The Intemational EECP Patient Registry (IEPR) collects data from 60 sites on consecutive chronic angina patients treated with EECP.The Duke Activity Index (DASI),a 12 item patient completed questionnaire,was used to measure functional capacity in patients before and after a course of EECP treatment.The Canadian Cardiovascular Society Classification (CCSC) of angina was used to monitor changes in angina.The majority of patients had severe angina,had prior invasive revascularization,but were not suitable for bypass surgery or percutaneous intervention.Functional status measured by the DASI questionnaire was poor at baseline,but improved significantly after EECP treatment.Co-morbidities although predictive of low baseline DASI,were not associated with failure to achieve functional improvement.