Research at St. Louis Heart & Vascular
Long-Term Improvement in Microvascular Angina Patients Treated With Enhanced External Counterpulsation
Kenneth D. Kronhaus, William E. Lawson, Lake Cardiology, Mount Dora, FL, SUNY Stony Brook, Stony Brook, NY
Background: Angina in patients without significant angiographic epicardial disease can be a medically refractory cause of chronic disability. Fort these microvascular angina patient Enhanced External Counterpulsation (EECP) may prove uniquely beneficial. Patent epicardial arteries facilitate transmission of the increased flow and pressure generated by EECP to the microcirculation and may promote angiogenesis, normalize endothelial function and improve myocardial perfusion and anginal symptoms. The benefit and durability of EECP therapy in these patients was studied.
Methods: Patients with atypical angina refractory to medical therapy and evidence of microvascular angina (a pharmacologic or exercise stress test with radionuclide or echocardiographic imaging [ST] showing regional ischemia together with a cardiac angiogram demonstrating no significant coronary disease) were treated with EECP. Angina, assessed by the Canadian Cardiovascular Society class [CCS], and stress tests were evaluated at baseline and after completing EECP treatment. Major cardiovascular events (cardiac hospitalization, death, infarction) were tracked for the duration of follow-up. Statistical analysis was performed with the student t test; significance level p < 0.05.
Results: Twenty one patients, 14 women and 7 men with a mean age of 68.5 years, received an average of 36.4 hours of EECP. CCS improved in all patients, the average baseline class of 3.8 improved to an early CCS of 1.4 [p < 0.05] and 6.3 month CCS of 1.2 [p < 0.05}. ST obtained a mean of 5.0 months post EECP showed complete resolution of defects in 16/17 cases [p < 0.05]. There was a durable reduction in angina in 20/21 patients at a mean 12.9 months of follow-up. With up to 19 months of follow-up only 1 patient had an adverse event [heart failure requiring admission] and increasing angina [treated with EECP].
Conclusions: Microvascular angina is effectively treated with EECP. There is a reduction in angina and provokable ischemia. The effect is durable with a low incidence of recurrent angina one year post treatment and few adverse cardiovascular events.
