Chronic stable angina enhanced external counter pulsation

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [mailto:mgibson@perfuse.org] Phone:617-632-7753; Associate Editor(s)-In-Chief: John Fani Srour, M.D.; Jinhui Wu, M.D.; Lakshmi Gopalakrishnan, M.B.B.S.

Overview
Enhanced external counter pulsation (EECP) is another alternative therapy in the management of refractory angina. Most data from observational studies have demonstrated significant improvement in the exercise tolerance and reduction in the frequency of anginal symptoms as well as the use of nitroglycerin among patients treated with EECP.

Mechanisms of Benefit

 * EECP has been postulated to decrease myocardial oxygen demand, enhance myocardial collateral flow via increased transmyocardial pressure, and improve endothelial function.


 * Decrease peripheral vascular resistance and increase ventricular function.


 * Increase arterial blood pressure and retrograde aortic blood flow during diastolic augmentation.


 * Possible placebo effect associated with EECP has not been addressed in many studies, which have not included sham controls.

Approach
EECP uses three paired pneumatic cuffs that are applied to the lower extremities. The cuffs are sequentially inflated then deflated.

The therapy is usually administered over 7 weeks consisting of 35-one hour treatments.

Randomized-Controlled Study

 * A multicenter, prospective, randomized, blinded, controlled trial involving 139 patients with angina, documented coronary artery disease and positive exercise treadmill test randomly assigned to receive either EECP (35 hours of active counterpulsation) or inactive EECP (over a 4- to 7-week period) to determine the safety and efficacy of EECP. The study demonstrated a significant improvement in the time to ST segment depression from baseline in the active EECP group (P=0.01). More active-EECP patients experienced a significant reduction in the frequency of anginal episodes (P=less than 0.05); however, the usage of nitroglycerin did not significantly change in both the groups. Thus, the study concluded that enhanced external counterpulsation significantly reduced angina and extended the time to exercise-induced ischemia in patients with symptomatic CAD.

Registry Studies

 * The International EECP Patient Registry (IEPR) involved 978 patients with refractory angina from 43 clinical centers to evaluate the safety and effectiveness of EECP in the management of chronic stable angina. Of the 978 patients analyzed, 70% had CCS class III or IV angina before the start of therapy, 62% used nitroglycerin, 81% had been previously revascularized, and 69% were considered unsuited for either PCI or CABG at the time of starting EECP. 86% patients completed a full 35-one hour course of EECP, of whom 81% reported a significant improvement of at least one angina class immediately after the last treatment.


 * A cohort study of 2,289 patients with refractory angina, from more than 100 centers, were evaluated to assess the safety and efficacy of EECP in the management of refractory angina. Angina class improved in 74% of patients with limiting angina (CCS class II-IV), with patients most impaired at baseline demonstrating the greatest improvement (39.5% of patients in CCS class III and IV improved 2 or more classes). The treatment was generally well tolerated and effective in patients ranging from 19 to 97 years.

==ACC/AHA Guidelines- Enhanced external counterpulsation (DO NOT EDIT) == {{cquote|

Class IIb
1. Enhanced external counterpulsation (EECP). (Level of Evidence: B)}}

Vote on and Suggest Revisions to the Current Guidelines

 * The Chronic Stable Angina Living Guidelines: Vote on current recommendations and suggest revisions to the guidelines

Guidelines Resources

 * The ACC/AHA/ACP–ASIM Guidelines for the Management of Patients With Chronic Stable Angina


 * The ACC/AHA 2002 Guideline Update for the Management of Patients With Chronic Stable Angina


 * Guidelines on the management of stable angina pectoris: The Task Force on the Management of Stable Angina Pectoris of the European Society of Cardiology


 * The 2007 Chronic Angina Focused Update of the ACC/AHA 2002 Guidelines for the Management of Patients With Chronic Stable Angina