EECP Protects Coronary Artery Disease Patients from Future Cardiac Events.* S. Karim et al 1st International Congress on Heart Disease – New Trends in Research, Diagnosis, and Treatment. The Journal of Heart Disease 1:1 May ’99 External Counterpulsation – Review Article. Xu-Yu-yun, Hu Da-yi, & Zheng Zhen-sheng. Chinese Medical Journal 103(9): 762-71, 1990 The published studies of EECP give us a clear message: EECP is an effective treatment for angina. In each study, be it American, Chinese, or Indonesian, just over 90% of patients improve. That EECP works well short term is now clearly established, but can EECP, or a program of EECP, have an effect on long term outcome? Dr. Lawson’s paper, showed us that five year outcome following EECP, when used to treat refractory symptoms in inoperable patients, was similar to that of low risk patients who underwent elective bypass surgery. But Lawson’s study involved only 33 patients. What effect will EECP have when larger groups of patients are studied, and for longer periods of time? Can a program based on EECP make a long term difference?
Karim and associates treated 117 patients with EECP between 1/92 and 12/97. Their outcome through 12/98 was then compared with that of 198 coronary patients who were treated over the same time period with standard drug therapy. The number of cardiac events (cardiac death, heart attack, need for invasive revascularization) occurring in each group over the seven year follow-up period was recorded. The average number of days elapsing between the initiation of therapy and the development of an event was calculated.
Here’s what Karim found:
Mean # Event Free Days
Karim found that patients treated with drug therapy alone were 2.3 times more likely to experience an adverse event during the seven year follow-up period. Unlike the MUST-EECP study<http://www.eecpworld.com/eecp/graphical/must-eecp.htm>, Karim’s study was not randomized or double-blind. The EECP patients knew they had received EECP. The drug group knew that they hadn’t. Still, the results are impressive, and patients are 2.3 times less likely to experience an adverse cardiac event.
In China, medical records are centralized, and standard measures are used to asses symptom severity and a patient’s response to treatment. By 1990, 1,800 EECP centers were up and running in China. In this 1990 paper, Dr. Xu Yu-yun and colleagues describe the short term effects of EECP in just over 6,000 patients. Long term outcome of 102 patients treated with EECP is compared with that of a similar group of coronary patients who received standard drug therapy alone. Here’s what they found:
Short-term effects on symptoms and EKG appearance were assessed in 6,116 patients treated with EECP
1.2% Total Effective Rate
Here again, just over 90% of patients treated with EECP improved. Long-term results were measured in 102 EECP patients; 23, 39, & 53 were followed for 7, 6, & 5 years post EECP respectively. 19, 32, & 52 patients treated solely with medication were followed over the same time periods.
Total Effective Rate – Symptoms Long-term: Symptoms
Drug Group 5 year follow-up
33.3% 6 year follow-up
48.1% 7 year follow-up
Total Effective Rate – EKG
Drug Group 5 year follow-up
31.2% 6 year follow-up
20% 7 year follow-up
Cardiac Death Rate
13.5% By Eighth Year
This was not a randomized, double blind study, but it involved a large number of patients and points to a definite, beneficial effect of EECP on long term outcome. In interpreting these numbers, keep in mind that in China EECP is often not just a one time treatment; Chinese patients not infrequently receive booster and maintenance sessions. In China the goal is to keep people healthy and out of the hospital, at the lowest possible cost, so they’re not shy about the use of EECP. They know that EECP helps long term. The question for us is, just why does EECP help long term? Could EECP have a favorable effect on atherosclerosis? Could EECP be altering our biochemistry in a positive way?
GUIDELINES BY INTERNATIONAL EECP PATIENT REGISTRY AT PITTSBURG-USA*
Clinical studies and data from the International EECP Patient Registry
(IEPR), coordinated by the Epidemiology Data Center at the University of Pittsburgh, continue to demonstrate that – 70–80% of patients realize therapeutic benefit immediately upon completion of a course of EECP therapy.
- At patient follow-up,therapeutic benefit is enhanced at six months and sustained at 24 months post treatment.
- Quality-of-life measures from a randomized trial and registry studies show significant improvement in the patients’ ability to resume activities of daily living, social interaction, and recreational pursuits.
Patient Selection and Treatment
EECP therapy is a safe and effective treatment that provides sustained duration of benefit in patients with disabling angina and angina equivalents, left ventricular dysfunction (LVD), and heart failure. EECP therapy is indicated for use in
(A) stable and unstable angina pectoris, (B) congestive heart failure, (C) acute myocardial infarction, and (D) cardiogenic shock. Patients that may benefit from EECP Therapy, Patients with *angina or angina equivalents who:
No longer respond to medical therapy
Restrict their activities to avoid angina symptoms
Are unwilling to undergo additional invasive revascularization procedures
Have LVD (EF <35%)
Have co-morbid conditions that increase the risk of revascularizationprocedures (e.g., diabetes, heart failure, pulmonary disease, renal dysfunction)
Have coronary anatomy unsuitable for surgical or catheter-based
Are considered inoperable or at high risk of operative/interventional Complications
Suffer with microvascular angina (Cardiac Syndrome X) Heart failure patients* in a euvolemic state with:
Ischemic or idiopathic cardiomyopathy
LVD (EF <35%)
Co-morbid conditions that increase the risk of complications of revascularization procedures
Diabetic patients known to be at greater risk for post-procedural complications.
Elderly patients at high risk for morbidity and mortality associated with invasive coronary interventions.
Arrhythmias that interfere with machine triggering
Severe lower extremity vaso-occlusive disease
Presence of a documented aortic aneurysm requiring surgical repair
Greater than Grade II aortic regurgitation
Patients with blood pressure *higher than 180/110 mmHg* should be controlled prior to treatment with enhanced external counterpulsation.
Patients with a heart rate of more than *120 bpm* should be controlled prior treatment with enhanced external counterpulsation.
Patients at high risk of complications from increased venous return should be carefully chosen and monitored during treatment with enhanced externalcounterpulsation. Decreasing cardiac afterload by optimizing cuff inflation and deflation timing may help minimize increased cardiac filling pressures and the possibility of pulmonary congestion due to increased venous return.
Patients with clinically significant valvular disease should be carefully chosen and monitored during treatment with enhanced external counterpulsation.
Certain valve conditions, such *as significant aortic insufficiency* or *severe mitral or aortic stenosis*, may prevent the patient from obtaining benefit from diastolic augmentation and reduce cardiac afterload in the presence of increased venous return.