6076Improvement of exercise capacity over the course of outpatient cardiac rehabilitation is an independent predictor of prognosis after a myocardial infarction

Abstract

Background Cardiac rehabilitation after myocardial infarction improves cardiovascular health and quality of life. However, data on long-term prognostic impact of surrogate rehabilitation parameters–such as exercise capacity improvements–remain scarce. Purpose To assess the independent prognostic impact of exercise capacity improvement over the course of outpatient cardiac rehabilitation after myocardial infarction. Methods Consecutive patients undergoing outpatient cardiac rehabilitation (3-times weekly for 12 weeks) after a myocardial infarction at a university centre were included. Exercise testing was performed at inclusion and after completion of the rehabilitation programme, with exercise capacity improvement defined as ≥2 MET increase over the course of the programme. Clinical data and risk factors were systematically collected, and patients were followed up for a minimum of 2 years. Kaplan-Meier curves and a multivariate Cox proportional hazard model were constructed for prediction of events (defined as a composite of incident cardiovascular death, re-infarction and coronary revascularsiation), with age, sex, LDL-cholesterol levels and body mass index as co-variates. Results A total of 409 patients were included (20% women). Exercise capacity and expected exercise performance were significantly improved after cardiac rehabilitation programme (6.6 to 9.5 METs, p<0.001, and 82 to 117%, p<0.001, respectively). After a median follow-up of 6.5 years, 93 patients experienced an event. Exercise capacity improvement of ≥2 METs was associated with reduced event rates (Figure 1), retaining statistical significance even after adjusting for age, sex, LDL-cholesterol and body mass index (HR 0.485, 95% CI 0.285–0.824). Kaplan-Meier curve Conclusion Improvement of exercise performance over the course of outpatient cardiac rehabilitation is an independent predictor of prognosis after a myocardial infarction, with improvements of ≥2 METs associated with a 50% reduction in events.