The multicenter study of enhanced external counterpulsation (MUST-EECP): effect of EECP on exercise-induced myocardial ischemia and anginal episodes.

OBJECTIVES The purpose of this study was to assess safety and efficacy of enhanced external counterpulsation (EECP). BACKGROUND Case series have shown that EECP can improve exercise tolerance, symptoms and myocardial perfusion in stable angina pectoris. METHODS A multicenter, prospective, randomized, blinded, controlled trial was conducted in seven university hospitals in 139 outpatients with angina, documented coronary artery disease (CAD) and positive exercise treadmill test. Patients were given 35 h of active counterpulsation (active CP) or inactive counterpulsation (inactive CP) over a four- to seven-week period. Outcome measures were exercise duration and time to > or =1-mm ST-segment depression, average daily anginal attack count and nitroglycerin usage. RESULTS Exercise duration increased in both groups, but the between-group difference was not significant (p > 0.3). Time to > or =1-mm ST-segment depression increased significantly from baseline in active CP compared with inactive CP (p = 0.01). More active-CP patients saw a decrease and fewer experienced an increase in angina episodes as compared with inactive-CP patients (p < 0.05). Nitroglycerin usage decreased in active CP but did not change in the inactive-CP group. The between-group difference was not significant (p > 0.7). CONCLUSIONS Enhanced external counterpulsation reduces angina and extends time to exercise-induced ischemia in patients with symptomatic CAD. Treatment was relatively well tolerated and free of limiting side effects in most patients.