ENHANCED EXTERNAL COUNTERPULSATION: INFORMATION FOR

PRIMARY CARE PROVIDERS

By

Stephanie Matlock, RN, BSN

Submitted in Partial Fulfillment of the Requirements for the Master of
Science in Nursing Degree

Edinboro University of Pennsylvania

Approved by:

Juchm Schilling, C
Ccnnmittee Chairperson

Kristine Komosa, CRNP, MSN
Consultants in Cardiology, Erie, PA
Committee Member

Daie

Date

i

C

Table of Contents
Contents

Page

Abstract...

iv

Acknowledgements

,v

Chapter 1: Introduction

1

Background of the Problem.

1

Coronary artery disease

2

Enhanced external counterpulsation,

3

Statement of the Problem.

3

Theoretical Framework.

4

Statement of the Purpose

5

Assumptions

5

Definition of Terms

5

Summary.

6

Chapter 2: Review of Literature
A New Approach to the Therapy of Angina Pectoris
Current angina therapy

7
7
7

Enhanced external counterpulsation (EECP)
in cardiovascular disease management

History of EECP

8

10

Development of EECP

10

EECP in the treatment of angina.

12

Efficacy ofEECP..

13

Reduction of angina and time
to exercise-induced ischemia

14

Improvement of exercise tolerance.

17

Long term effects ofEECP

19

Psychological and Neurological Impacts of Coronary Artery Disease

21

Treatment of coronary artery disease and adverse neurological outcomes.

22

Psychosocial outcomes ofEECP

.24

Summary.
Chapter 3: Methodology
Model for Evaluating Printed Education Materials.

.25

26
.26

Predesign phase

26

Design phase

26

Pilot test phase.

27

Implementation/distribution phase.

28

Summary

28

References

29

Appendixes

34

A. Questionnaire for Evaluation............................................................

.35

B. Enhanced External Counterpulsation: ANoninvasive Treatment for

Coronary Artery Disease

36

iv

Abstract
The purpose of this project was to develop an informative article on enhanced

external counterpulsation (ECCP) therapy. It focuses on providing primary care

providers with knowledge about EECP and its potential benefits for their patients.
EECP is a noninvasive outpatient treatment for coronary artery disease that has been

successful for some patients whose angina pectoris has not responded to medical and/or
surgical therapy (Cohn, Hui, & Lawson, 2000). Patients undergo EECP treatment 1 hour
per day for a total of 35 treatments (Cohn et al., 1995). Each treatment involves external

cuffs applied to the patient’s calves, thighs, and buttocks (Burger, Guo, Hui, Lawson, &

Soroff, 1997). Sequential inflation during diastole using EKG timing results in more

effective coronary artery perfusion (Burger, Guo et al., 1997).
Research data suggest that EECP may provide adjunctive therapy for patients

suffering from stable angina (Crawford, Feldman, Schneider, & Soran, 1999). Primary
care providers, including nurse practitioners, play an important role in coordinating

patient care and must know how to screen and refer patients appropriately (Cram &
Ettinger, 1998).

EECP has demonstrated usefulness in improving exercise tolerance, treating angina,
and decreasing cardiac radionuclide perfusion defects (Cohn, Hui, & Lawson, 2000).
Dorothea E. Orem’s (2001) Self-care Deficit Theory of Nursing provided the conceptual

framework for this project.

V

Acknowledgements
This scholarly project took many months of hard work and dedication. Many people

helped to make the completion of this project possible. I would like to take this
opportunity to thank those who helped me reach my goal.

First I would like to thank Dr. Judith Schilling for her knowledge and guidance as my
committee chairperson. Without her this project would have not been possible. Next I

would like to thank Kristine Komosa for being a valuable part of my committee. Her
knowledge in cardiology was truly an asset to this project. Another valuable person
involved in the achievement of this scholarly project was Sue Simon. I want to thank her

for her time and support. Finally, I would like to thank all my family and friends,

especially my husband Kevin, for being so supportive when I was overwhelmed with my
studies. My personal time was limited and everyone was extremely patient. Without

their support and patience, I would have not been able to complete my project so

diligently.

1

Chapter 1
Introduction
This chapter provides a brief overview of coronary artery disease, angina, and

enhanced external counterpulsation (EECP) therapy. This project was inspired by a lack

of information on the benefits of EECP in primary care practice. Its purpose was to

develop an informative article on EECP to provide primary care providers with

knowledge about EECP and its potential benefits for their patients. Dorothea E. Orem’s
(2001) Self-care Deficit Theory of Nursing provided the conceptual framework for this

scholarly project. The background of the problem, the problem statement, purpose of the
study, assumptions, and pertinent definitions are included in this chapter.

Background of the Problem
The magnitude and prevalence of cardiovascular disease in the United States makes it
the leading cause of morbidity and mortality (Cohen, 1999). There are a host of options

available to practitioners treating patients with cardiovascular disorders such as non-

surgical and surgical revascularization, and drug therapy.
A noninvasive treatment called enhanced external counterpulsation (EECP) for

coronary artery disease has been used successfully for patients with angina pectoris who

are not responsive to medical and/or surgical therapy (Cohn, Hui, & Lawson, 2000). This
treatment has been found to be safe and without serious adverse effects in patients who
do not meet specific exclusion criteria (Crawford, Feldman, Scheinder, & Soran, 1999).

Today, managed care companies are encouraging primary care providers to limit
referrals to specialists and provide nee<:ded services themselves (Cram & Ettinger, 1998).
Primary care providers, including nurse

practitioners, play an important role in

2

coordinating patient care. Practitioners act as an entry point for patients in deciding what
services may be needed and, therefore, they most screen and refer patients appropriately

(Cram & Ettinger).

Coronmy artery disease. Despite a decline in death rates from coronary artery disease,
it is still the leading cause of morbidity and mortality in the United States (Institution for

Clinical Systems Integration [ICSI], 1997). Coronary artery disease is a chronic

condition with extended long-term survival rates because of secondary and tertiary

prevention by practitioners (Arora et al., 1999). Many patients are seen with recurrent

angina despite coronary revascularization and anti-ischemic agents (Arora et al.).
Strabos (1999) noted that chest pain is one of the most common complaints in
ambulatory practice. Coronary artery disease is commonly manifested as angina pectoris

(Luscher, 2000). As many as 5.6 million people in the United States suffer from angina
pectoris, and as many as 350,000 new cases are seen yearly (Tartaglia, 1996). Anderson,

Anderson, and Glanze (1990) defined angina pectoris as a paroxysmal thoracic pain
caused by myocardial anoxia resulting from atherosclerosis of the coronary arteries.

Angina is often accompanied by the feeling of suffocation and impending death. These
attacks can be precipitated by emotional stress, exertion, and exposure to intense cold.
Relief of this pain can be achieved by resting or by vasodilatation of the coronary arteries

(Anderson et al., 1990).
There has been an increasing number of patients with anginal symptoms over the past

decade that are unresponsive to medical treatment, and who are not candidates for
revascularization procedures (Crawford, Feldman, Schneider, & Soran, 1999). Research

3

data suggest that EECP may be helpful adjunctive therapy for patients with coronary
artery disease suffering from this problem.

Enhancedextemal countopdsat^^

The concept of counterpulsation was

first introduced in the United States by Kantrowitz in 1953 (Crawford, Feldman,

Schneider, & Soran, 1999). Counterpulsation-induced elevations of aortic diastolic

pressure improve coronary blood flow by as much as 40% (Cohn et al., 2000). In the
1960s, groups began exploring noninvasive methods for producing the physiological

effects of counterpulsation (Crawford et al., 1999). Then in 1975, the air-driven EECP

system was developed, consisting of three sets of balloons that wrap around the patient’s
lower legs, mid-thighs, and upper thighs (Crawford et al.).

EECP applies external pressure to the lower extremities and buttocks in a sequential
and EKG timed manner (Burger, Cohn et al., 1997). The sequentially applied air

pressure from the lower body upward causes a milking of blood toward the heart
(Crawford, Feldman, Schneider, & Soran, 1999). This enhances coronary artery

perfusion during diastole, and perhaps facilitates development of coronary collaterals
(Burger et al., 1996). The mechanism responsible for the beneficial effects of EECP

remain undefined (Crawford et al., 1999). Recent scientific investigations suggest that
chronic exposure to EECP induces shear stress which might result in the release of

growth factors and stimulate angiogenesis in the coronary beds (Crawford et al.)
Statement of the Problem

Coronary artery disease is the leading cause of death for both men and women in the

United States (U.S. Public Health Service, 1998). Arora et al. (1999) wrote that
practitioners will see patients with recurrent angina despite medical treatments and

4

interventions. EECP has been proven successful in relieving angina. Although the
benefits of EECP are well known among cardiovascular specialists, less literature about
this beneficial therapy is directed toward the primary care providers.

Theoretical Framework

Dorothea E. Orem s (2001) Self-care Deficit Theory of Nursing provided the
theoretical framework for this project. Orem noted that self-care is performed by mature

individuals in deliberate response to a need. Orem’s theory includes several components:
(a) self-care agency, (b) self-care deficit, (c) therapeutic self-care demand, and (d)

nursing agency.
Self-care agency is described as the ability to perform self-care that will promote life,

health, and well-being (Orem, 2001). Therapeutic self-care demand is all the self-care

actions that a patient needs to perform at any given time to maintain health and promote

well-being. According to Orem, patients have a self-care deficit if they do not have the
ability to meet their therapeutic self-care demands. Nursing agency is the specialized
abilities of nurses. Nursing agency is needed when patients are unable to meet their

therapeutic self-care demands.
One major goal of nurse practitioners is to help patients meet their therapeutic selfcare demands. In order to achieve this goal the nurse practitioner acts as a nursing agent
for the patient. The nurse agent assesses the functional ability of patients with chronic

stable angina to identify self-care deficits. Maher (1998) wrote that functional ability

assessment includes basic activities of daily living (ADLs) and instrumental activities of
daily living (IADLs). Self-care activities that people must be able to do without
assistance to survive are considered ADLs (Maher, 1998). If patients live independently

5

they must also be able to perform required activities, such as housework which is
considered an IADLs (Mayer).
As nurse practitioners, if a patient is found to have a functional self-care deficit related

to angina, action is needed to improve the patient’s self-care agency. When usual
medical treatments are not effective, then other options should be explored. The nurse

practitioner acting as a nursing agent with knowledge of EECP and its effectiveness can
facilitate self-care agency and optimize self-care agency in patients with chronic stable

angina.
Statement of the Purpose
The purpose of this scholarly project was to develop an informative article on EECP

therapy to be submitted for publication in a journal for primary care providers. This
article provides primary care providers with knowledge about EECP therapy and its

potential benefits for their patients.

Assumptions
For the purpose of this project, the following assumption was made:

1. Primary care offices have an adult population of patients who could potentially
benefit from EECP therapy.

Definition of Terms
The following terms have been defined for this study:

1. Enhanced external counterpulsation (EECP) is a noninvasive procedure that applies
external pressure to the lower body in a sequential, EKG-timed manner, using pneumatic
cuffs to enhance filling of the coronary arteries during diastole (Cohn, Hui, & Lawson,
2000).

6

2. Counterpulsation is the action of circulatory-assist pumping device that is

synchronized counter to the regular action of the heartbeat (Anderson, Anderson, &

Glanze, 1990).
3. Diastolic augmentation is an increase of arterial blood pressure and retrograde

aortic blood flow that occurs in diastole caused by counterpulsation (Arora et al., 1999).

4. Angina pectoris is the result of myocardial ischemia, which is caused by an
imbalance between the myocardial oxygen requirements and the supply of oxygen
(Braunwald, 1997).
5. Chronic stable angina is caused by flow-limiting coronary artery stenoses of

variable severity with the residual coronary blood flow being preserved at the
micro vascular level (Braunwald, 1997).
Summary
Ischemic heart disease is one of the most common diseases managed by family
practitioners (Gersh, Solomon, & Zanger, 1999). In the time of managed care, primary

care providers must manage illnesses within their scope of practice, and know when to
refer for additional treatment (Cram & Ettinger 1998). Orem’s Self-care Deficit Theory

(2001) was conceptual framework for this project and was utilized based on the concept
that primary care providers help patients to achieve health, well-being, and maximal

independence. The assumptions and terminology of this project were presented.

7

Chapter 2
Review of the Literature
This chapter provides an overview of current modalities in the treatment of angina,

and the role of enhanced external counterpulsation (EECP) in cardiovascular disease

management. A brief history of EECP is also presented. Finally, the efficacy of EECP
and psychosocial aspects are discussed.

A New Approach to the Therapy of Angina Pectoris
Myocardial ischemia can be alleviated by a noninvasive method called EECP

(Amsterdam, 1997). Today, primary care providers have an array of treatment options

for patients with heart disease (Cohen, 1999). EECP is a noninvasive therapy that is
unfamiliar to most clinicians and may warrant closer attention (Tartaglia, 1996).

Current angina therapy. Great progress has been made in the treatment of angina
pectoris since a century ago when short-acting nitrates were introduced (Amsterdam,
1997). In the past 4 decades treatments have focused on the pathophysiology of

myocardial ischemia (Amsterdam). Additional medications used to treat angina became

available in the 1960s and 1970s such as beta-adrenergic blocking agents and calcium

channel blockers (Luscher, 2000). These drugs act on myocardial ischemia by

decreasing myocardial oxygen demand (Amsterdam). Some patients, however,
experience unwanted side effects (Arora et al., 1999).

In the 1970s revascularization by coronary artery bypass (CABG) surgery or

percutaneous transluminal coronary angioplasty (PTCA) came into use (Luscher, 2000).
Revascularization can be very effective in a significant number of patients (Arora et al.,

8

1999). However, revascularization is verv meth, 4 •
s very costly and is associated with morbidity and
mortality (Amsterdam, 1997).

Despite all these traditional treatments, practitioners will still see patients with
recurrent angina (Arora et al., 1999). („ light of

the

for

,herapeu(ic

options for patients with angina, such as EECP, continues.

EECP in cardiovascular disease management. In the past 10 years, there has been an

increasing number of patients who present with anginal symptoms, but are unresponsive
to medical therapy and are not candidates for revascularization (Crawford, Feldman,

Schneider, & Soran, 1999). A new option for these patients is EECP. It has been
approved by the Food and Drug Administration for the treatment of stable and unstable

angina, cardiogenic shock, and acute myocardial infarction (Amsterdam, 1997). Most
clinical investigations are focused on EECP treatment for stable angina (Amsterdam).

The groups of patients who seem to benefit most from EECP are those who have had
previous coronary bypass surgery, whose lesions are not suitable for percutaneous
catheter procedures, or those with restenosis following revascularization with PTCA

(Crawford et al., 1999).

Coronary artery disease management involves evidence-based cost-effective
prevention, education, diagnostic services, and treatment (Baklajian, Hannan, &

Strobeck, 1997). Goals of disease management are to: (a) prevent as much new disease
as possible, (b) assess and identify severity of existing disease, and (c) in severe forms of
disease, treat the patient maximally to provide disease stabilization. According to

Baklajian et al. (1997) stabilized coronary artery disease should result in: (a) reduction of
coronary events, (b) reduced ER visits and hospital admissions for angina, (c) reduction

9

of nitrate use and anginal episodes, (d) improvement h myocardi„

(e)

improved functional status.
EECP is a noninvasive method that has contributed to disease stabilization in some

patients that would have otherwise required revascularization surgery (Baklajian,
Hannan, & Strobeck, 1997). EECP therapy represents an adjunctive therapy available to
patients on an outpatient basis to postpone the need for the more costly and invasive

inpatient treatments (Baklajian et al., 1997). EECP is safe and without serious adverse
effects when patients are selected appropriately (Crawford, Feldman, Schneider, & Soran,

1999).
Patients that should be excluded from EECP (Baklajian, Harman, & Strobeck, 1997)
are those with evidence of aortic aneurysm, severe ileofemoral occlusive disease, or

evidence of lower extremity deep vein thrombosis. Caution is advised in patients with an
ejection fraction less than 30% (Baklajian et al., 1997). Vasomedical, Inc. (1995) lists

the following as some contraindications for EECP: (a) aortic insufficiency, (b) cardiac

catheterization within 1-2 weeks, (c) arrhythmia that might interfere with the triggering
of the EECP system e.g. atrial flutter, atrial fibrillation, ventricular tachycardia, (d)
congestive heart failure, (e) severe hypertension (>180/1 lOmmhg), (f) peripheral vascular

disease, (g) pregnancy, and women of childbearing age without reliable contraception, (h)

recent myocardial infarction, (i) non-:ischemic cardiomyopathy, and (j) bleeding diathesis,

coumadin therapy with PT > 15.
Patient selection for inclusion for EECP treatment noted by Baklajian, Hannan, and
Strobeck (1997) were: (a) patients who have undergone at least one poor

revascularization procedure and are in need of another, as long as they have at .east one

10

open conduit to the distal coronary artery bed, (b) patients with single or double-vessel
coronary artery disease unsuitable for PTCA or stent implantation, and (c) patients with
triple-vessel disease, diffuse in nature, with unsatisfactory distal bypass target vessels as

long as at least one artery does not have a severe proximal obstruction.

History of EECP
EECP was developed about 40 years ago, and found a significant place in China

where it has been used for over two million patients (Tartaglia, 1996). The concept of

counterpulsation was introduced in the United States by Kantrowitz and Kantrowitz with
the proposal that elevating aortic diastolic pressure could benefit patients with coronary
insufficiency by improving coronary blood flow (Crawford, Feldman, Schneider, &

Soran, 1999).

Development of EECP. In 1953 it was shown that coronary artery blood flow could
increase 20% to 40% if the coronary arteries where perfused at an elevated pressure
during diastole (Giron, Hui, & Soroff, 1997). Although studies came to suggest that

counterpulsation could improve coronary blood flow and would benefit patients with

coronary artery insufficiency, developing the necessary technology proved to be a
challenge (Crawford, Feldman, Schneider, & Soran, 1999).
In 1955, Adler et al. assisted the circulation in a patient with heart failure by
venoarterial bypass in which venous blood was withdrawn into an oxygenator and
returned to arterial circulation by a pump. This type of assisted circulation, however, was

not effective in decreasing myocardial oxygen consumption.

In 1958, Case et al. showed that tension or duration pressure generated by the left
ventricle is an important determinant of the heart’s oxygen consumption. Soroff and his

11

colleagues demonstrated that co-'Unterpulsation produced a reduction in the consumption

of oxygen m the left ventricle as a result reducing systolic pressure (Giron, Hui, & Soroff,
1997).

In 1966, Birtwell et al. released a study on assisting circulation by synchronous
pulsation of extramural pressure. Their approach was theoretically based on the idea that
the arterial vascular bed, which normally acts to store a large part of the ventricular

energy output passively, can be activated by introducing external energy during diastole
by synchronous pulsation of extramural pressure. By using a pressure chamber with

pneumatic control on dogs to apply the synchronous pulsation of extramural pressure, the
study indicated that cardiac output, venous return, and aortic systolic and diastolic

pressures could be modified to reduce left ventricular workload, meanwhile increasing
cardiac output.

The initial equipment consisted of a hydraulically driven unit with a pair of waterfilled bladders to be wrapped around the thighs and lower legs of the patient (Crawford,

Feldman, Schneider, & Soran, 1999). Suboptimal diastolic augmentation was achieved

with this equipment because the tissue mass to which the external pressure could be
applied was limited (Crawford et al., 1999).

In China in 1976, a four-limb sequential external counterpulsation system combined

with the use of buttock balloons driven by a air compression pump was developed (Cai et
al., 1983). By applying timed sequential pressure using these pneumatic cuffs, effective
diastolic augmentation can be achieved (Cohn, Hui, & Lawson, 2000). Milking of blood

from the vasculature of the lower body by sequential inflation of these cuffs is more
effective than the earlier hydraulic method in increasing venous return (Cohn et al.,

12

2000). It was demonstrated that adding buttocks cuffs mcreased diastolic augmentation
by 44% (Crawford, Feldman, Schneider, & Soran, 1999).

Augmenting aortic diastolic pressure increases the perfusion pressure to coronary

arteries and the transmyocardial pressure gradient, which possibly enhances the
development of coronary collateral vessels (Burger et al., 1996). According to Crawford,
Feldman, Schneider, and Soran et al. (1999) scientific investigations are suggesting that

shear stress induced by repeated exposure to EECP might result in the release of growth

factors and subsequent stimulation of angiogenesis within the coronary vasculature.

EECP in the treatment of angina. According to Cohn, Hui, and Lawson (2000)
enhanced external counterpulsation has been useful in improving exercise tolerance,

treating anginal symptoms, and decreasing radionuclitide stress perfusion defects in many
patients. It is believed that EECP recruits collateral channels to areas of ischemia in the

myocardium, diminishing angina and reducing or even eliminating areas of poor
perfusion (Giron, Hui, & Soroff, 1997). Physiologic effects of EECP are accomplished

by raising the supply of oxygen to the myocardium by increasing diastolic perfusion
pressure to benefit patients with ischemic disease (Atkins et al., 1992).

Currently, the device used for EECP was developed by Dr. Zhen-Shen Zheng in China
and brought to the United States by Drs. Harry Soroff and John Hui in 1989 for research

trials (Burger, Guo et al., 1997). EECP applies timed external pressure to the lower body

in a sequential manner, using three pairs of pneumatic cuffs (Cohn, Hui, & Lawson,
2000). The external cuffs are applied to the calves, thighs, and buttocks and the
sequential inflation occurs

during diastole using EKG timing to result in effective filling

of coronary arteries (Burger, Guo

et al.). The pressure is released during systole,

13

reducing cardiac work and afterload, thereby decreasing myocardial energy requirements

(Cohn et al., 1995). The action of EECP is similar to the intra-aortic balloon pump
(IABP) in producmg timed diastolic augmentation (Cohn et al., 2000). However, EECP

differs from IABP hemodynamically in that it directly increases venous return and this

benefits the patient’s cardiac output (Burger, Guo et al.).
EECP therapy usually consists of 1 hour of out patient treatment for 35 days over a

span of 7 weeks (Cohn et al., 1995). During the treatment the patient is placed to a bed­

like apparatus with six air valves that emits rhythmic thumping sounds (Cohn et al.). It
involves wrapping balloon cuffs all wrapped around the patient’s legs, thighs and
buttocks (Cohn et al.). The synchronous pulsatory pressure applied sequentially from the

calves to the buttocks milks the venous blood back to the heart to increase diastolic
pressure and coronary blood flow in order to foster collateralization (Cohn et al.).
Efficacy of EECP

EECP has been used successfully as a noninvasive treatment for coronary artery

disease in patients not responding to medical and/or surgical treatment (Cohn, Hui, &

Lawson, 2000). According to Crawford, Feldman, Schneider, & Soran (1999) EECP has

proved to be useful in the therapy of patients with chronic angina, and studies in the past

decades have supported the hypothesis that EECP can produce long-term benefits in
patients with angina secondary to coronary artery disease.

Arora et al. (1999) suggested that EECP could reduce time to angina and extend time
to ischemia in patients experiencing symptoms from coronary artery disease. The

improved exercise tolerance seen in patients studied by Atkins et al. (1992) helped to

14

prove the efficacy of EECP. Finally, EECP is also suggested to have secondary benefits
of decreased anxiety and depression (Burger, Cohn, Fife et al., 1997).

Reduction of angina and time to exercise-induced ischemia. A study done by Atkins et
al. (1992) included 18 patients, one woman and 17 men, with incapacitating angina and
baseline thallium 201 perfusion imaging showing evidence of exertional ischemia within

1 week prior to EECP treatment. All patients received the same EECP treatment, 1 hour

each day for a total of 36 hours. Approximately 1 week after therapy was completed, a

maximal stress test was performed. All 18 patients had improvements in anginal
symptoms after the treatment and, of the 18 patients, 16 had complete relief of angina

during usual daily activities. Pre and post-Thallium-201 stress testing showed complete
resolution of ischemic defects in 12 patients (67%). Two patients had a decrease in the

area of ischemia (11%), and four patients had no change (22%). In summary, a total of
14 patients had a reduction in myocardial ischemia as evaluated by Thallium-201 .

imaging (p= < 0.01).
A larger randomized study, the Multicenter Study of Enhanced External

Counterpulsation (MUST-EECP) trial, was conducted in the United States at seven
medical centers (Arora et al., 1999). It was the first randomized controlled study
designed to evaluate the efficacy of EECP in patients with angina and coronary artery

disease. The primary endpoints were exercise duration, time to > 1-mm ST-segment
depression, angina counts, and nitroglycerine usage. Five hundred patients with chronic
stable angina were considered ftr inclusion with 139 being randomized between May

1995 and lune 1997 for the trial. Eligible patients met the following criteria: (a) between

ages of 21 and SI, (b) angina symptoms in levels I, H, or 111 consistent with Canadian

15

Cardiovascular Society Classification system (Campeau, 1976), (c) documented evidence
of coronary artery disease, and (d) an exercise treadmill test (ETT) positive for ischemia.

A baseline ETT was performed within 4 weeks prior to initiation of the treatment. These

patients were given active or inactive counterpulsation (CP), which consisted of thirtyfive 1-hour treatments. The active-CP group had 300 mm Hg of cuff pressure. The

inactive-CP or control group had 75 mm Hg of cuff pressure, enough to mimic the feel
and appearance of EECP. An ETT was performed within 1 week after completion of 35
treatment sessions.
Exercise duration was defined as time from initiation of exercise to the beginning of
the recovery period and was measured in seconds, which was compared pre and post

treatment (Arora et al., 1999). In the active-CP group, exercise duration was 426 + 20
seconds at baseline and 470 + 20 seconds post-CP (p<0.001). In the inactive-CP group,

exercise duration was 432 + 22 seconds at baseline and 464 ± 22 seconds post-CP
treatment (/?<0.03). No significant change in exercise duration was noted between the

two groups from baseline to post treatment (adjusted mean: active-CP: 42+11 seconds

vs. inactive-CP: 26 + 12 seconds; p> 0.3).
Ischemia was measured by time to > 1-mm ST-segment depression (Arora et al.,
1999). In the active-CP group, time to >l-mm ST-segment depression improved from
337 to 379 (± 18) seconds post EECP (p= <0.002). In the inactive-CP group, time to >1 -

mm ST-segment depression differed from 326 (± 21) seconds at baseline to 330 (± 21)

seconds post EECP (p<0.74). There was a statistically significant difference between the
groups’ time to > 1-mm ST-segment depression from baseline to post treatment (adjusted
mean: active-CP: 37 ± 11 seconds vs. inactive-CP: -4 ± 12 seconds; p=0.01).

16

Angina counts were considered the average frequency of anginal episodes per day,

calculated by dividing the number of anginal episodes reported at three consecutive
treatment sessions by the number of days in which the sessions took place (Arora et al.,

1999). The difference in angina counts between baseline and post treatment were

calculated as a percentage change. Data on angina counts from patients completing the
therapy (> 34 treatments) were available for 59 patients in the inactive-CP group, and 57

patients in the active-CP group. The first three sessions were considered as the baseline
period. The patients in the active and inactive groups were then classified into these
categories: (a) 50%+ improvement, (b) 25% to 49% improvement, (c) 0% to 24%

improvement, (d) 1% to 25% worsening, (e) 26% to 50% worsening, (f) 51% to 100%

worsening and (g) > 100% worsening. Patients who had no angina episodes at the first
three sessions were considered as having no change (0%) if they continued to have no
episodes at other sessions. The same patients were considered as 100% worsening if they

developed episodes after the first three sessions. The analysis of on-demand
nitroglycerine tablets per day (nitroglycerine count) was calculated in the same manner as
the angina counts.
The active-CP group’s average angina counts were 0.72 ± 0.14 at baseline and 0.57 ±

0.38 post treatment (Arora et al., 1999). In the inactive-CP group, angina counts were
0.77 ± 0.14 at baseline and 0.76 ± 0.22 post treatment. The difference between the

groups’ angina episodes before and after completing treatment was significant (adjusted
mean: active-CP: -0.033 ± 0.27 vs. inactive-CP: 0.15 ± 0.27; p< 0.035). In the group of
patients who completed therapy, nitroglycerine use was 0.39 ± 0.11 at baseline, and 0.43

± 0.21 after treatment. The difference between the two groups nitroglycerine usage

17

before and after treatment

was not significant (adjusted mean: active-CP: - 0.32 ±0.15

vs. inactive-CP -0.19 + 0.14; p> 0.1).

In both treatment groups adverse events were recorded at each session (Arora et al.,
1999). Adverse events were reported more by the patients in the active-CP group 39

(55%) than the inactive-CP group 17 (26%), p< 0.001. The majority of events (47 of 95)
reported by both groups were considered to be device-related such as paresthesias,

edema, abrasions, bruising, or pain (legs or back). However, only 5 patients withdrew
from the study due to leg complaints.

Improvement of exercise tolerance. Burger et al. (1996) performed a study to
determine the effects of EECP therapy on exercise tolerance and exercise hemodynamics
in a group of patients with chronic stable angina. Twenty-seven patients, including 1

woman and 26 men with a mean age of 60, were enrolled in the study. A baseline

maximal radionuclide stress test was performed before entering the study and after the

therapy was completed, each using the same cardiac workload. Radionuclide images
were evaluated and classified as either improved (partial or complete resolution of
reversible defects) or unimproved. The stress tests before and after 35 treatments, each in

1 to 2 hour increments, were evaluated for changes in exercise duration in minutes,
maximal heart rate in beats per minute, and blood pressure in mm Hg.
The pre and post maximal stress results were compared using the paired two-tailed

Student’s t test (Burger et al., 1996). The patients were subgrouped by either improved
or unimproved radionuclide stress tests and separately analyzed. Linear regression was

also used to evaluate the data’s correlation (Pearson’s product moment correlation

coefficient and Spearman’s rank correlation coefficient) between the change in exercise

18

tolerance, changes in blood pressure, heart rate, and double product (heart rate x systolic
blood pressure) during maximal exercise in all patients.

Radionuclide stress perfusion imaging improved in 21 patients (78%) after receiving
EECP therapy (Burger et al., 1996). These subjects had an increased exercise duration
from 7.22 ± 0.63 to 9.12 ± 0.60 minutes (p< 0.0005) after EECP. Heart rate, blood

pressure, and double product showed insignificant change after EECP. For all 27 patients
treated with EECP, exercise duration on the Bruce protocol maximal stress test improved

from 7.17 + 0.53 minutes to 8.84 + 0.49 (p< 0.0001). Improved exercise tolerance was
seen after receiving EECP in 22 out of 27 patients (81%). In the subgroup of 6 patients

with unimproved perfusion imaging no significant differences were noted before and

after EECP therapy in exercise tolerance, maximal heart rate, or maximum systolic blood
pressure.

Increases in heart rate with maximal exercise were demonstrable in the patients
showing improved myocardial perfusion and correlated with the increases in exercise
duration (Burger et al., 1996). However, the increases in exercise duration were

associated with lower than expected heart rates and insignificant increases in the blood
pressure. This effect of heart rate response to exercise could have been due to

chronotropic insufficiency, drug effect, or increases in stroke volume and conditioning.
Blood pressure response, similarly, may have been due to left ventricular dysfunction,
drug effect, or decreased peripheral resistance. However, drug therapy was kept constant

and myocardial perfusion improved, making left ventricular dysfunction, drug effect, or
chronotropic insufficiency unlikely. Resulting increased stroke volume from decreased

peripheral resistance, in contrast, could not be excluded.

19

This study suggested that the increase in duration of exercise after treatment with

EECP was a result of improvement in myocardial perfusion (shown by improved stress

radionuclide perfusion), and a decrease in peripheral vascular resistance (similar to the

effect of exercise training) (Burger et al., 1996).
Long term effects of EECP. In a study done by Cohn et al. (2000) patients who

received EECP therapy were evaluated to determine their long-term prognosis. A cohort
of consecutive patients with angina and treated with EECP from 1989 to 1991 were

followed for a mean of 5 years. The study planned to determine whether there was
evidence for a sustained benefit from EECP treatment by assessing major adverse
cardiovascular events (MACE) 5 years post treatment. MACE endpoints were: death,

myocardial infarction, coronary artery revascularization surgery, and cardiac related

hospitalization.
All subjects had a radionuclide stress test showing reversible perfusion defects

consistent with ischemia. Thirty-three patients enrolled in and completed the therapy of
35 to 36 hours of EECP administered for 1 to 2 hours daily, 5 days a week.

Characteristics of the patients in the study were as follows: (a) 73% had multivessel
disease by coronary angiogram, (b) 45% had prior myocardial infarctions, and (c) 61

had prior revascularization procedures. Twelve patients included in the 61% had a total
of 17 prior coronary artery bypass grafting (CABG). Fifteen patients also included in the

61% had a total of 33 prior percutaneous transluminal coronary angioplasty (PTCA).

Seven of these patients had both prior PTCA and CABG. Some exclusions for treatment

included decompensated heart failure, myocardial infarction in the past 3 months,
unstable angina, aortic valve insufficiency, peripheral vascular disease, arrhythmias

20

interfering with tinting such as atrial fibrillation, uncontrolled hypertension (> 180/110

mmHg), or bleeding diathesis.
A radionuclide stress test was performed pre and post EECP treatments at the same
cardiac work load was evaluated blindly by trained readers with no knowledge of the

patient’s clinical condition (Cohn, Hui, & Lawson, 2000). Based on the stress

radionuclide perfusion imaging post EECP therapy, two groups of patients were
identified and classified into subgroups: (a) responders: patients showing a decrease in
the size or number of perfusion defects, and (b) nonresponders: patients without evidence

of perfusion defect improvement. The differences pre and post treatment, and between
the subgroups, were evaluated using the chi-square test, significance assumed at the p<

0.05 level. Analysis of patient baseline characteristics predicting a favorable response to

the treatment was performed at the same level of significance.
Initial results demonstrated that EECP was well tolerated in all the patients completing

the course of therapy, and all patients reported a decrease in angina symptoms (Cohn,

Hui, & Lawson, 2000). After the therapy, decreased medication usage were noted: (a)

long acting nitrate use decreased by 21%, (b) 13% of patients decreased beta-blocker use,

(c) calcium-channel blockers use also decreased by 7%, and (d) 33 /o (11 patients) were
able to take one or more fewer antianginal medications.
Improvement in radionuclide stress testing after the treatment, compared to the same
stress test given before therapy, demonstrated a significant (p< 0.01) improvement in
perfusion defects in 26 of the 33 (79%) patients (responders). In 7 patients, perfusion
defects were unchanged (nonresponders) (Cohn, Hui, & Lawson, 200 )

21

In the course of the mean 5-year follow up, 13 of 33 patients (33%) underwent

additional EECP treatments (Cohn, Hui, & Lawson, 2000). MACE occurred in 6 of the 7
patients (86%) m the nonresponder group. In the responder group 6 of 26 patients (23%)

reached MACE chosen endpoints (p< 0.01). In all, 21 of the 33 (64%) patients treated
with EECP remained alive and free of MACE 5 years after initial treatment. None had

cardiovascular morbidity or needed repeat revascularization. The 5-year survival of

patients who were treated with EECP was 88%. Cohn et al. (2000) wrote that this is
similar to the mortality rates reported in other medical and revascularization (CABG or
PTCA) trials such as the Coronary Artery Surgery Study, the CABG meta-analysis, and

the Bypass Angioplasty Revascularization Investigation.
This expanded cohort study with a 5-year follow-up by Cohn, Hui, and Lawson (2000)

focused on MACE or the need for revascularization within 5 years of follow-up. In the
group of responders to EECP, a decreased frequency of death and major adverse

cardiovascular events was significant, as compared to nonresponders (23% vs. 86%; p<

0.01). The low occurrence of post treatment events suggests that EECP may be a long­
term, noninvasive, cost-effective treatment for selected patients with chronic angina.
Psychological and Neurological Impacts of Coronary Artery Diseasg

Mental stress has a known effect on angina, and risk factors for sudden cardiac death
include states of chronic and acute stress mediated through the central nervous system

(Cohn et al., 1995). As the brain triggers a sympathetic nervous system response, the
heart’s vascular and platelet environment may be set up for an ischemic response with
angina as the end result (Cohn et al.).

22

Treatment of

Technology continues to reduce the morbidity and mortality associated with CABG

procedures (Burger, Cohn, Fife, et al., 1997). Howeyer, Bashein et al (1939) made it
clear that the prevalence of major neurologic injury and of neuropsychiatric disturbances

have not decreased following CABG procedures. In fact, Henriksen (1934) measured the
regional cerebral blood flow of patients before and after open-heart surgery. The study
showed that the mean cerebral blood flow fell in 24 of 31 patients. These marked

changes in cerebral blood flow after surgery indicate evidence of diffuse brain damage in

patients following most cardiac operations.
Later, Aggarwal et al. (1996) in the Multicenter Study of Peri-Operative Ischemia
Research and Education Foundation found that 129 out of 2108 patients had serious

adverse cerebral outcomes after cardiac surgery. Two types of adverse cerebral outcomes
were seen. Type I was represented by focal injury, stupor, or coma, and Type II was
deterioration in intellectual function, memory deficit, or seizures.

It is suggested that adverse cerebral outcomes after CABG are serious and relatively
common (Aggarwal et al., 1996). The patients with adverse cerebral effects had higher

in-hospital mortality and also had a longer hospitalization after surgery. These patients
also had higher rates of discharge to other facilities for intermediate or long-term care.
The study authors felt that it is imperative that new therapeutic and diagnostic strategies

be developed to alleviate these adverse cerebral outcomes following CABG.
A recent study, Medical Care Costs and Quality of Life after Randomization to

Coronary Angioplasty or Cow Bypass Surgety (Boothroyd et al., 1997), assessed
medical costs and quality of life after randomization to PTCA or CABG. Niue hundred

23

thirty-four patients were studied, collecting yearly quality of life data and quarterly
economic data. To assess quality of life the Duke Activity Status Index, a measure of the

ability to perform activities of daily living, was used. After 3 years, the CABG patients
had greater improvement in functional status scores than did patients who had PTCA.
The Rand Mental Health Inventory was also administered, a five item scale with totals

ranging from 0-100 (higher scores representing better mental health), to assess anxiety,

depression, and positive affect. The median scores for PTCA and CABG patients were

both 76.0.
The cost of the two procedures and return to work were other factors evaluated in the

study by Boothroyd et al. (1997). The patients in the PTCA group returned to work 5
weeks sooner than the CABG patients, and the mean cost of PTCA was 35% lower than
that of uncomplicated surgery. However, after 5 years the total medical expense acquired

by PTCA patients was up to 95% of surgery. The study indicated that CABG correlates
with a better quality of life than PTCA in patients with multivessel disease when the
initial higher morbidity of the CABG procedure is eliminated (Boothroyd et al., 1997).

Most recently a study published in The New England Journal ofMedicine found that
patients whose cognitive function declines immediately after coronary bypass surgery
(which is approximately 50% of all patients who endure CABG) are at an increased risk

for long-term cognitive descent and a decreased level of overall cognitive functioning
(Blumenthal et al., 2001).

Neurocognitive tests were performed on 261 patients at Duke Heart Center from
March 1989 through November 1993 prior to CABG, before hospital discharge, at 6

weeks following discharge, at 6 months, and 5 years after their surgery (Bluntenthaiet

24

.1,2001). The weli validated battety of five tests induded; (a) the

short-story module of

the Randt Memory Test, (b) the Digit Span subtest of the Weehsler Adult Intelligence
Scale-Revised, (c) the Benton Revised visual Retention Test, (d) the Digit Symbol subtest

of the Wechsler Adult Intelligence Scale-Revised, and (e) the Trial Making Test.

Of the 261 patients, 176 were available for the 5 year follow up, which was complete
in November 1998 (Blumenthal et al., 2001). Cognitive decline was evident in 53% of
the patients upon discharge testing. At 6 weeks the incidence of cognitive decline

decreased to 36 /o of patients, and was at 24% of patients at the 6 month follow up.
Finally, 5 years after the surgery, the incidence of cognitive decline was evident in 42%
of patients. This study demonstrated statistically significant associations of cognitive

decline after CABG; early cognitive impairment is clinically a precursor for later
cognitive impairment.
Psychosocial outcomes of EECP. Cohn et al. (1995) published a pilot study on the
psychosocial adjustment associated with EECP. Patients were given a psychosocial

battery pre-EECP (first day of treatment) and post-EECP (last day of EECP). This

included the Psychosocial Adjustment to Illness Scale-Revised (PAIS-R) which is a self­

reported measure that evaluates seven areas of adjustment to illness, as well as a
questionnaire on pain, exercise, and medication needs. An additional questionnaire on

quality of life was administered only post-EECP.

Twelve patients completed the PAIS-R before and after EECP treatment (Cohn et al.,

1995). Results were fisted as mean scores ± standard deviation. In all the twelve subjects

only the area of extended family relationships showed a statistically significant difference

(54.1 ± 7.2 pre-EECP and 58.2 ± 6.2 post-EECP^ 0-05). A significant decrease in the

25

number of times subjects experienced chest pain (p^p 3 , ± 2 2 B „ 6 ± „ ,
EECPp < 0.01), severity of the chest pain (pre.EECP 2.9 ± 0.8 to 1.7 ± 1.0 post-EECP, p

< 0.05), and frequency of nitrate use (pre-EECP 2.3 + 2.5 to 0.1 ± 0.4 post-EECP, p <
0.10) was found on the subject questionnaire.

Nine of the twelve subjects co:mpleted the quality of life questionnaire administered

post-EECP (Colin et al., 1995). The results reported using descriptive statistics
demonstrated a 100% improvement in the subjects’ ability to work, energy levels, and

overall well-being. It was also noted that two of the respondents showed no evidence of
improvement of ischemia post-EECP, however, they reported improved quality of life.

EECP seemed to be well tolerated psychologically and resulted in reduced stress,
improved ability to work, improved health condition, and improved overall well being

(Cohn et al.).
Summary
This literature review included several of the current therapies used to treat chronic
angina, and how EECP can be used as a therapy in cardiovascular disease management
for these patients with chronic angina. The history of the development of EECP, and

theories of how the mechanism of EECP helps patients with angina, are discussed.

Finally, clinical research studies supporting the idea that EECP therapy can be used as a
treatment for angina demonstrating effectiveness physiologically, as w
psychosocially, were also presented.

26

Chapter 3
Methodology

The purpose of this schdarly project

t0 develop m

enhanced external counlerpulsation therapy (EECP) to be submitted for publication in a
scholarly journal for primary care providem. This chapter discusses the development of

the article using the model for Evaluating Printed Education Materials (EPEM)

developed by Bernier and Yasko (1991).
Model for Evaluating Printed Education Materials
Bernier and Yasko’s (1991) EPEM model is composed of five phases: predesign,
design, pilot test, implementation/distribution, and evaluation. The first four phases of

the EPEM model helped to guide the development of this article to enhance the
knowledge base of primary care providers when assessing and identifying patients who

may benefit from EECP.
Predesign phase. During the predesign phase, the need for an article to educate
primary care providers about EECP was determined by the lack of published information

about EECP therapy directed specifically toward them. The purpose of this article was
then identified: to provide primary care providers with knowledge about EECP therapy
and its potential benefits for their patients. Important areas of content would include
coronary artery disease as an increasing problem for patients and their primary care
providers, a brief history of EECP, the tele of EECP in cardiovascular disease

management, and its effectiveness as a treatment for angina.
Design phase During the design phase, the most significant information was chosen
based on the review of literature. Then contents were carefully selected based on

27

Mistical data and evidence concerning the use of EECP as effectivelament for angim.

in patients unresponsive to traditional treatment methods.

Pilot test phase. The pilot test phase of this project included having the first draft of
the article reviewed by a cardiologist who specializes in noninvasi™ diagnostics and

treatments, a nurse practitioner who works in cardiac services, and a registered nurse who

manages a cardiology EECP laboratory on a daily basis. These professionals were asked
to provide feedback on the clarity and informative content of the article. The draft article

and questionnaire for evaluation (Appendix A) were then distributed to four primary care

providers, including two nurse practitioners. The primary care providers were asked to

read the article and complete the questionnaire. Feedback from the three cardiac health
care professionals and the three primary care providers who returned the questionnaire
was used to evaluate and revise the article.

The cardiologist suggested to possibly include more detailed information on how the

physiologic effects of EECP are accomplished. The cardiac nurse practitioner did
suggest mentioning some adverse events that were reported in the MUST-EECP trial that
were device-related, so that the reader could have an idea of what patients could possibly
expect during treatment. The registered nurse who manages an EECP clinic had several

suggestions. First, she agreed with the nurse practitioner that some adverse events should
be included. Next, she felt that insurance coverage for EECP therapy should be stated so
primary care providers will know who the treatment would be paid for before they refer

for treatment. She also wanted the article to contain different types of treatment
prescriptions such as a patient who may receive up to two hours of treatment at one time.

She also gave more current resources of information containing inclusions and

28

contraindications for EECP treatment, which were then utilized
based on her personal experience as an EECP

in the article. Finally,

nurse, she discussed practical aspects of

EECP, and also the opportunities taken by her to deliver patient education on diet,
exercise and medications during treatment. The article was then amended to reflect that.

The primary care providers all felt that the information was new and helpful. They
agreed that the purpose of the article was clear. One nurse practitioner did feel that it was
important to include information on where patients can be referred for EECP treatment.

A web site on EECP was then added to the article containing that specific information.

The other nurse practitioner agreed with the EECP nurse that insurance coverage was
important and should be included.

Implementation/distribution phase. The final article (Appendix B) was submitted to a

peer-reviewed nurse practitioner journal. The article will then be reviewed for possible
publication.

Summary

In summary, the purpose of this scholarly project was to develop an informative
article for primary care providers on EECP, its uses, and identification of patients with

symptomatic coronary artery disease who may benefit from EECP therapy. Development
of the article was guided by the EPEM model by Bernier and Yasko (1991). The article

was submitted for possible publication to a peer-reviewed nurse practitioner journal.

29

References
Adler, S., Dennis, C., Fries, C., Gliedman M
vneaman, M„ Gorayeb, E„ Karlson, K„ Levowitz, B„
Newman, M. Stuckey, J., Young, L„ & Zuhdi, M. (1955). Complete and partial

person of animal and human subjects: A study of factors yeilding consistent survival.
Successful application to one case. Surgery,38. 30-37

Aggarwal, A., Graham, S. H„ Kanchuger, M„ Ley, C„ Mangano, C. M„ Mangano, D.
T„ Marschall, K„ Newman, M„ Nussmeier, N„ Ozanne, G„ Roach, G. W„ & Wolman,

R. (1996). Adverse cerebral outcomes after coronary bypass surgery. The New England
Journal of Medicine, 335, 1857-1862.
Amsterdam, E. A. (1997). Enhanced external counterpulsation: Chronicle of a new

approach to the therapy of angina pectoris. Cardiovascular Reviews & Reports (pp. 3-5).
Greenwich, CT: Cardiovascular Reviews & Reports, Inc.

Anderson, K. L., Anderson, L. E., & Glanze, W. D. (Eds.) (1990). Mosby’s medical

dictionary (3rd ed.). St. Louis: C.V. Mosby Company.
Arora, R. R., Chou, M. T., Crawford, L., Fleishman, B., Jain, D., McKierman, T., &
Nesto, W. R. (1999). The Multicenter Study of Enhanced External Counterpulsation

(MUST-EECP): Effect of EECP on exercise-induced myocardial ischemia and angmal
episodes. Journal of the American College of Cardiology, 33J 833-1840.
Atkins, H„ Cohn, P. F., Hui, J. C. K., Kayden, D. S., Lawson, W. E, Sasvary, D„

Soroff, H. S„ & Zheng, Z. S. (1992). Efficacy of enhanced external counterpulsation in
the treatment of angina pectoris. TheAmeric^^

859-862.

30

Baklajian, R„ Hannan, J., & Strobeck,j. E (1997)

external counterpulsation in cardiovascular disease management. In Cardiovascular
Reyiews&Reports (pp. 6-11). Greenwich, CT: Cardiovascular Reviews & Reports, Inc.

Bashein, G„ Bledsoe, S. W„ Cohen, M. A., Coppel, D. B., Davis, K. B„ Goldstein, D.
E., Hombein, T. F., Ivey, T. D., Nessly, M. L., Townes, B. D., & Veith, R. C. (1989).
Neurobehavorial outcomes in cardiac operations. Journal of Thoracic and Cardiovascular

Surgery, 98, 774-782.
Bernier, M. J., & Yasko, J. (1991). Designing and evaluating printed education

materials: Model and instrument development. Patient Education and Counseling, 18,

253-263.

Birtwell, W., Collins, J., Deterling, R., Giron, F., Ruiz, U., & Soroff, H. (1966).
Assisted circulation by synchronous pulsation of extramural pressure. Surgery, 60, 894-

901.
Blumenthal, J., Gaver, V., Grocott, H., Jones, R., Kirchner, J., Mark, D., Newman, M.»

Phillips-Bute, B., & Reves, J. (2001). Longitudinal assessment of neurocognitve function

after coronary-artery bypass surgery. The New England Journal of Medicine,344, 395402.

Boothroyd, M. S„ Brooks, M. M„ Hlatky, M. A., Johnstone, I., Pitt, B„ Mark, D. B„
Reeder, G„ Rogers, W. J., Ryan, T, Smith, H., & Whitlow, P. (1997). Medical care costs

and quality of life after randomization to coronary angioplasty or coronary bypass
surgery. The New England JounialofMgdi£fflgU& 92'98'

31

Br^. B. (1997). Chronic coronary

E

;

& J. D. Rutherford. (Eds.).

1289-1349). Philadelphia, PA: W.B. Saunders Company.
Burger, L„ Cohn, P„ Fife, A, Fricchione, L. G, Hui, J. P, landorf, L„ Lawson, W.

E, & Vaccaro, B. (1997). Psychosocial aspects of enhanced external counterpulsation. In
Cardiovascular Reviews & Reports (pp. 23-27). Greenwich, CT: Cardiovascular Reviews
& Reports, Inc.

Burger, L., Cohn, P. F., Hui, J. C. K., Jiang, L., Lawson, W. E., Lillis, O., Oster, Z.,
Soroff, H., & Zheng, Z. S. (1996). Improved exercise tolerance following enhanced

external counterpulsation: Cardiac or peripheral effect? Cardiology, 87,271-275.
Burger, L., Guo, T., Hui, J. C. K., Lawson, W. E., & Soroff, H. S. (1997)

Enhanced external counterpulsation: US clinical research. In Cardiovascular Review &
Reports (pp. 18-23). Greenwich, CT: Cardiovascular Review & Reports, Inc.

Cai, S„ Chen, G„ Chen, B„ Chen, P„ Chen, Y., Huang, B„ Kambic, H„ Hong , M.,
Nose, Y., Wo, S., Zhan, C., & Zheng, Z. (1983). Sequential external counterpulsation
(SECP) in China. Transactions-American Society for Artificial Internal Organs, 29, 593603.

Campeau, L. 1976. Letter: Grading of angina pectoris. Circulation, 54, 522-523.
Cohen, J. (1999). Cardiovascular disease: Tomorrow is the reason for today s
therapeutics. Geriatrics, 54(3), 57-63.

Cohn, P. F., Fricchione, G. L., Hui, J. C. K., Jaghab, K., Jandorf, L., Lawson, W.,
Soroff, H„ & Zheng, S. Z. (1995). Psychosocial effects of enhanced external
counterpulstion in the angina patient. Psychosomatics,

>

32

Cohn, P. F., Hui, J. C. K., & Lawson, W E oonm t
’(2000)' Long-term prognosis of patients
with angina treated with enhanced externa! co«erpulsati„„: Five.year

Clinical Cardiology, 23, 254-258.

Cram, P„ & Ettinger, W. (1998). Generalists er speeialista-Who does it better?.

Physician Executive, 24(1), 140-146.
Crawford, L. E„ Feldman, A. M„ Schneider, M. V., & Soran, 0. (1999). Enhanced

external counterpulsation in the management of patients with cardiovascular disease.
Clinical Cardiology, 22, 173-178.

Gersh, B. J., Solomon, A. J., & Zanger, D. R. (1999). Contemporary management of

angina: Part 1. risk assessment. American Family Physician 60,2543-2552.
Giron, F., Hui, J. C. K., & Soroff, H. S. (1997). Historical review of the development

of enhanced external counterpulsation technology and its physiologic rationale. In
Cardiovascular Review & Reports (pp. 28-31). Greenwich, CT: Cardiovascular Reviews

& Reports, Inc.

Henriksen, L. (1984). Evidence suggestive of diffuse brain damage following cardiac
operations. The Lancet, 1(8381),816-820.

Institute for Clinical Systems Integration (1997). Ijpid scrgening in adults: Working
to prevent coronary artery disease. Minneapolis, MN: Author.

Luscher, T. F. (2000). Treatment of stable angina. BritishMedicalJouniaL (7253), 62
64.
Maher, L. (1998). A practical guide to screening and assessment. Patien

31-32, 34, 39, 43-44, 46, 51, 54, 62, 64, 67.
Orem, D. E. (2001). NursmgLCQnceptsXW^

,th ed.). St. Louis: Mosby.

33

Strabos, C. N. (1999). Angina pectoris. In R. L.
(Eds>). Principles of ambulatory medicine (5th

Barker, J. R. Burton, & P. D. Zleve,

ed.)(pp. 721-744). Baltimore, MD:

Williams & Wilkins.

Tartaglia, J. (1996). Simple compressive air cuffs are now available in the U.S. for
angina. Modem Medicine, 64(4); 12.

U.S. Public Health Service (1998). Clinician’s handbook of preventative services. (2nd
ed.). McLean, VA: International Medical Publishing, Inc.
Vasomedical, Inc. (1995). Clinical training resource manual. (3rd ed.). Westbury, NY:

Author.

34

Appendixes

35

Appendix A
Questionnaire for Evaluation

1. Was the purpose of the article clear to you?

2. Was the content of the article explained clearly and in a logical manner?

3. Was the information presented new and helpful?

4. Is there any other information that you think should be included in the article?

5. Do you have any other comments or suggestions?

36

Appendix B

Enhanced Externa! Counterpulsation: A Nomnvasive Treahnent for
Coronary Artery Disease
Despite a decline in death rates from coronary artery disease, it is still the leading

cause of morbidity and mortality in the United States

Strabos noted that chest pain is

one of the most common complaints in ambulatory practice2. As many as 5.6 million
people in the United States suffer from angina pectoris, and 350,000 new cases are

diagnosed yearly . Some patients experience recurrent angina despite coronary
revascularization and anti-ischemic medications4.

A noninvasive treatment called enhanced external counterpulsation (EECP) for

coronary artery disease has been used successfully for patients with angina pectoris who
are not responsive to medical and/or surgical therapy5. EECP applies external pressure

to the lower body in a sequential, EKG-timed, manner using pneumatic cuffs wrapped
around the legs, thighs, and buttocks, this enhance filling of the coronary arteries during
diastole 5. A typical course of EECP therapy involves 35 treatments that last at least one

hour each, during which time the patient may listen to music or watch television3. This

may also present an opportunity for patient teaching concerning diet, exercise, and
medications.
EECP was developed about 40 years ago in China where it has been used for over two
million patients

The concept of conntetpulsation was introduced in the United States

by Kantrowitz and Kantrowitz in 1953 with the proposal that devating aortic diastolic

pressure could benefit patients with coronary "sufficiency by nnprovmg « artery
blood flow

Developing the necessary technology, however, proved io he a cWienge.

37

the mid-1960s, research groups began exploring noninvasiee methods for producing

the physiologic effects of counterpulsriiou. The iritial equipment consisted of a

hydraulically driven unit with a pair of water-filled bladders to be mapped around the
patient’s thighs and lower legs6.

In 1976, a four-hmb sequential external counterpulsation system, combined with the
use of buttock balloons driven by an air compression pump, was developed in China7.

Milking of blood from the vasculature of the lower body by sequential inflation of these
cuffs was more effective than the earlier hydraulic method in producing increased venous

return and enhanced filling of the coronary arteries during diastole5.
The device used for EECP was developed by Dr. Zhen-Shen Zheng in China and
brought to the United States by Drs. Harry Soroff and John Hui in 1989 for research trials

8. EECP applies timed external pressure to the lower body in a sequential manner, using
three pairs of pneumatic cuffs5. During the treatment the patient is placed on a bed-like

apparatus with six air valves that emits rhythmic thumping sounds9. The external cuffs
are applied to the calves, thighs, and buttocks and the sequential inflation occurs during

diastole using EKG timing. This results in more effective filling of the coronary arteries
8. The pressure is released during systole, reducing cardiac work and afterload, thereby

decreasing myocardial energy requirements . The synchronous pulsatory pressure
applied sequentially from the calves to the buttocks milks venous blood back to the heart

to increase coronary blood flow and diastolic pressure, and may foster collateralization

According to Crawford et al. scientific investigations are suggesting that shear stress
induced by repeated exposure to BECP might also result in the release of growth lactors

and subsequent stimulation of angiogenesis within the coronary vasculature >.

38

A study by Atkins et al. included 18 patients with
■
pauents with incapacitating angina and baseline

thallium-201 imaging showing evidence of exertional ischemia ». Each patient received

the same EECP treatment, one hour each day for a tola! of J6 hours. All 18 patients bad
complete relief of angina during usual daily activities. Pre and post-Thallium-201 stress

testing showed complete resolution of ischemic defects in 12 patients (67%). Two

patients had a decrease in the area of ischemia (11%), and 4 patients had no change
(22%). In summary, a total of 14 patients had a reduction in myocardial ischemia as
evaluated by Thallium-201 imaging (p=<0.01).

Cohn et al. published a pilot study on the psychosocial adjustment associated with
EECP 9. Twelve patients completed the Psychosocial Adjustment to Illness Scale­
Revised (PAIS-R) and a subjective pain and disability assessment pre-EECP (first day of
treatment) and post-EECP (last day of treatment). Additionally, a quality of life

questionnaire was administered post-EECP. All 12 patients demonstrated a statistically

significant improvement in mean scores in the area of extended family relationships (p <

0.05). On the subjective questionnaire a significant decrease in the number of times
subjects experienced chest pain (p < 0.01), the severity of the chest pain (p < 0.05), and

frequency of nitrate use (p

0.10) was found. All 12 patients reported 100%

improvement in ability to work, energy levels, and overall well-being on the quality of
life questionnaire that was administered post-EECP treatment.
A larger randomized study, the Multicenter Study of Enhanced External

Counterpulsation (MUST-EECP) trial, was conducted in the United States at seven

medical centers \ One hundred thirty-nine patients were randomized between May 1995

and June 1997. Eligible patients met the Mowmg criteria: (a) between 21 and 81 years

39

of age, (b) angina symptoms in levels I, II, or III consistent with the Canadian

Cardiovascular Society Classification system, (c) documented evidence of coronary
artery disease, and (d) an exercise treadmill test (ETT) positive for ischemia. These
patients were given active counterpulsation (cuff pressure of 300mm Hg) or inactive
counterpulsation (cuff pressure of 75mm Hg). An ETT was performed within 1 week

after therapy was completed to assess exercise duration and time to ischemia; anginal
episodes and nitroglycerine used during the course of therapy were also evaluated. No
significant change in exercise duration was noted between the two groups from baseline

to post treatment (p > 0.3). Ischemia was measured by time to > 1-mm ST-segment
depression. There was a statistically significant difference between the two groups’ time

to exercise-induced ischemia from baseline to post treatment (adjusted mean: active

EECP: 37+11 seconds vs. inactive EECP: -4 + 12 seconds: p = 0.01). The study also
showed a significant difference between the groups’ angina episodes before and after

completing treatment (adjusted mean: active EECP: -0.033 + 0.27 vs. inactive EECP:
0.15 + 0.27: p < 0.035). Finally, the amount of nitroglycerine used by patients at baseline

and post treatment was not significantly different.
In both treatment groups adverse events were recorded at each session . Adverse

events were reported more by the patients in the active-CP group, 39 or 55 /o, than by

patients in the inactive-CP group, 17 or 26%, (p<0.001>. The majority of events (47 of

95) reported by both groups were considered to be device-related such as paresthesias,
edema, abrasions, bruising, or pain (legs or back). However, only 5 patients withdrew
from the study due to leg complaints.

40

In 1996 Burger et al. performed a study to determine n. «•
y o determine the effects of EECP therapy on
exercise tolerance and exercise hemodynamics

For

therapy, exercise duration on the maximal stress test improved from

± „ 53

to S.S4 ± 0.49 (p < 0.0001). An improved exercise tolerance was seen alter completing

EECP therapy in 22 of 27 patients (81%). A baseline nwtimal radionuclide stress test
was performed on the 27 patients before entering the study and after EECP therapy was

completed. Radionuclide stress perfusion imaging improved in a total of 21 patients
(78%) after receiving 35 EECP treatments, each in one to two hour increments. In these
21 patients exercise duration was also improved significantly (from 7.22 + 0.63 to 9.12 ±
0.60 minutes (p < 0.0005). In the subgroup of 6 patients with unimproved perfusion

imaging no significant difference was noted before and after EECP therapy in exercise
tolerance.
Recently, an expanded cohort study of 33 patients was completed by Cohn et al.5. It

focused on assessing major adverse cardiovascular events (MACE) over a 5-year post­
treatment period to determine the long-term prognosis of patients who received EECP

therapy. Twenty-six of 33 patients (79%) demonstrated significant improvement in
myocardial perfusion defects (p < 0.01). These patients had a significant decrease in

frequency of death and MACE as compared to nonresponders (p < 0.01). The low

occurrence of post-treatment events suggested that EECP might be a long-tenn,

noninvasive, cost-effective treatment for selected patients with chronic angina.
EECP is safe and without serious adverse effects when patients are selected appropriate^
‘ The group of patients who seem to tenefh the n»st horn EECP, but are not temted to

are those who have had previous comnary bypass surgery, whoso lesions me not smtable

41

for percutaneous catheter procedures, or those with resten„sis followtag
with percutaneous transluminal coronary angioplasty (PTCA)6

The some criteria for patient selection for EECP treatment stated by Vasomedical, Inc.
but not limited to, is that the patient must be diagnosed with angina pectoris- class HI or

IV and in the opinion of a cardiologist or cardiovascular surgeon must not be a candidate
for surgical intervention 12. Some criteria for patient inclusion for EECP therapy noted
by Baklajian et al. were the following: (a) patients who have undergone at least one prior

revascularization procedure and are in need of another, as long as they have one open
conduit to the distal coronary bed, (b) patients with single or double-vessel coronary
artery disease not suitable for PTCA or stent implantation, and (c) patients with triple-

vessel disease, diffuse in nature, with unsatisfactory distal bypass target vessels without
severe proximal obstruction I3.
Patients that should be excluded from EECP, according to Baklajian et al. are those

with evidence of aortic aneurysm, severe ileofemoral occlusive disease, or lower
extremity deep vein thrombosis. Caution is advised for patients with an ejection fraction
less than 30% 13. Exclusion criteria identified by Atkins et al. (1992) were aortic

insufficiency, myocardial infarction in the past three months, nonischemic

cardiomyopathy, severe hypertension (>180/110), and peripheral vascular disease .
Vasomedical, Inc. lists the following as some of the contraindications fo

cardiac catheterization within 1-2 weeks, (b) arrhythmia that might interfere with the
triggering of the BECP system e.g. atrial fibrillation or ventricular taohycar a, ( )

congestive heart Mure, (d) pregnancy, and women of childbearing age without reliable
contraception, (e) bleeding diathesis, coumadm therapy with PT

42

IlBurmCe coverage is always an issue for new treatments. As of My 1, lw> the

Health Care Financing Administration (HCFA) has provided coverage for EECP therapy
to Medicare patients who have been diagnosed with class HI or class IV angina pectoris

(Canadian Cardiovascular Society Classification or equivalent classification), and who
are not a candidate for surgical intervention in the opinion of a cardiologist or
cardiovascular surgeon 12.

In conclusion, we know that ischemic heart disease is one of the most common
diseases managed in family practice 16. Studies have demonstrated that EECP is useful in

improving exercise tolerance, treating angina, decreasing cardiac perfusion defects in
patients with coronary artery disease, and most of all improving quality of life5.
Practitioners act as an entry point for patients in deciding what services may be

needed and, therefore, they must screen and refer patients appropriately 17. Patients with
anginal symptoms refractory to medical or surgical treatment, and who are not candidates

for revascularization procedures, are encountered increasingly in the primary care

environment 6. The clinician with knowledge of the benefits of EECP, and the ability to
screen and refer the appropriate patients for this treatment, can provide a useful adjunct to

conventional medical therapy for angina6. For more information about EECP therapy
patients and providers and a list of treatment centers, log on to www.eecn.

18

43

References

,. tnsmute for Clinical Sys,ems Integrariom

*

prevent coronary artery disease. Minneapolis, MN: Author, 1997;17]-177
2. Strabos CN: Angina Pectoris. In: Barker RL, Burton JR, Zleve PD, eds. Principles

of ambulatory medicine, 5*1 edition. Baltimore, MD: Williams and Wilkins, 1999;712-

744.
3. Tartaglia J: Simple compressive air cuffs are now available in the U.S. for angina.

Modern Med 1996;64(4): 12.
4. Arora RR, Chou MT, Crawford L, Fleishman B, Jain D, McKierman T, Nesto WR:
The multicenter study of enhanced external counterpulsation (MUST-EECP): effect of

EECP on exercise-induced myocardial ischemia and anginal episodes. J Am Coll Cardiol

1999;33:1833-1840.
5. Cohn PF, Hui JCK, Lawson WE: Long-term prognosis of patients with angina
treated with enhanced external counterpulsation: five-year follow-up study. Clin Cardiol

2000;23:254-258.

6. Crawford LE, Feldman AM, Schneider MV, Soran 0: Enhanced external

counterpulsation in the management of patients wiiith cardiovascular disease. Clin Cardiol

1999;22:173-178.
7. Cai S, Chen G, Chen B, Chen P, Chen Y, Huang B, Kambic H, Hong M, Nose Y,

Wo S, Zhan C, Zheng Z: Sequential external coimterpulsation (SBCP) in China.
Am Soc for ArtifIntern Organs 1983;29:593-603.
s. Burger L, Guo T, Hui JCK, Lawson WE, SoroffHS: Enhanced exte

dounterpulsation: US dtaical research. Custar

.WriW •

44

9. Cohn PF, Fncchione GL, Hui JCK, Jaghab K, Jandorf L, Lawson W, Soroff H,
Zheng SZ: Psychosocial effects of enhanced extena.1 connterptdsation in the angina

patient. Psychosomatics 1995;36:494-497

10. Atkins H, Cohn PF, Hui JCK, Kayden DS, Lawson WE, Sasvary D, Soroff HS,
Zheng ZS: Efficacy of enhanced external counterpulsation in the treatment of angina

pectoris. Am J Cardiol 1992;70,859-862.

11. Burger L, Guo T, Hui JCK, Jiang L, Lawson WE, Lillis O, Oster Z, Soroff H,
Zheng ZS. Improved exercise tolerance following enhanced external counterpulsation:

cardiac or peripheral effect? Cardiol 1996;87:271-275.
12. Vasomedical, Inc. (2001). Vasomedical EECP [On-line]. Available:
http:/Anvw.naturalb\,pass.com/naturalb\rpass reimbursement.htm.

13. Baklajian R, Hannan J, Strobeck JE: The emerging role of enhanced external

counterpulsation in cardiovascular disease management. Cardiovascular
Reviews &Reports 1997;18:6-11.

14. Vasomedical, Inc. (1995). Clinical training resource manual. (3rd ed.). Westbury,
NY: Author.
15. 16. Gersh BJ, Solomon AJ, Zanger DR: Contemporary management of angina:
part 1. risk assessment. Clin Cardiol 1999;22:173-178.

16. Cram P, Ettinger W: Generalists or specialists—who does it better? Physician

Executive 1998;24(l):140-146.
17. Vasomdeical, Inc. (1999). EECP Treatment Relief from Angina. [Brochure].

Westbury, NY: Author.