History of erectile dysfunction as a predictor of poor physical performance after an acute myocardial infarction

Background: Erectile dysfunction may predict future cardiovascular events and indicate the severity of coronary artery disease in middle-aged men. The aim of this study was to evaluate whether erectile dysfunction (expression of generalized macro-and micro-vascular pathology) could predict reduced effort tolerance in patients after an acute myocardial infarction. Patients and methods: One hundred and thirty-nine male patients (60 +/- 12 years old), admitted to intensive cardiac rehabilitation 13 days after a complicated acute myocardial infarction, were evaluated for history of erectile dysfunction using the International Index of Erectile Function questionnaire. Their physical performance was assessed by means of two six-minute walk tests (performed two weeks apart) and by a symptom limited cardiopulmonary exercise test (CPET). Results: Patients with erectile dysfunction (57% of cases) demonstrated poorer physical performance, significantly correlated to the degree of erectile dysfunction. After cardiac rehabilitation, they walked shorter distances at the final six-minute walk test (490 +/- 119 vs. 564 +/- 94 m; p< 0.001); at CPET they sustained lower workload (79 +/- 28 vs. 109 +/- 34 W; p< 0.001) and reached lower oxygen uptake at peak effort (18 +/- 5 vs. 21 +/- 5 ml/kg per min; p = 0.003) and at anaerobic threshold (13 +/- 3 vs. 16 +/- 4 ml/kg per min; p = 0.001). The positive predictive value of presence of erectile dysfunction was 0.71 for low peak oxygen uptake (< 20 ml/kg per min) and 0.69 for reduced effort capacity (W-max < 100 W). Conclusions: As indicators of generalized underlying vascular pathology, presence and degree of erectile dysfunction may predict the severity of deterioration of effort tolerance in post-acute myocardial infarction patients. In the attempt to reduce the possibly associated long-term risk, an optimization of type, intensity and duration of cardiac rehabilitation should be considered.