Patients with refractory angina often suffer from erectile dysfunction.Enhanced external counterpulsation (EECP) decreases symptoms of angina,and increases nitric oxide release.This study evaluated the effect of EECP on sexual function in men with severe angina.The International Index of Erectile Function (IIEF) was used to assess erectile function of severe angina patients enroled in the International EECP Patient Registry.Their symptom status,medication use,adverse clinical events and quality of life were also recorded before and after completing a course of EECP.