The immediate and one-year outcomes of dialysis patients with refractory angina treated by enhanced external counterpulsation

Abstract

Adult dialysis patients with angina pectoris refractory to medical treatment or revascularization are not uncommon. Enhanced external counterpulsation (EECP) has been proven to be effective in reducing myocardial ischemia and refractory angina. The objective of this study was to assess the immediate and 1-year effects of EECP treatment in dialysis patients with refractory angina. Thirty-six consecutive dialysis patients were treated with EECP, and a follow-up was conducted after 1 year. The Canadian Cardiovascular Society (CCS) Angina Grading Scale was used to measure angina severity. Medications were recorded before EECP treatment, at the end of treatment, and at 1-year follow-up. Adverse events and risk factors of cardiovascular disease were recorded and analyzed. At 1-year follow-up, data from patients improving by at least one CCS class after treatment were compared with data from patients showing no improvement. The improvement rates in CCS class were 85% immediately after EECP and 66% at 1-year follow-up. Thallium-201 myocardial perfusion imaging demonstrated a reversible resolution of 40% and improvement of 25% immediately after EECP treatment. Diabetes mellitus and high serum phosphate levels were risk factors affecting whether the beneficial effects of EECP treatment could be sustained (p < 0.05). Major adverse events were rare. EECP shows potential for refractory angina in dialysis patients. The beneficial effects were sustained for more than 1 year in 66% patients. Diabetes mellitus and high serum phosphate levels were major factors impacting the sustained effectiveness of EECP treatment. Nonetheless, adequately powered future studies are necessary to assess safety and efficacy of this procedure.