The impact of physical training on endothelial function in myocardial infarction survivors: pilot study

Background: Endothelial dysfunction (ED) may indirectly influence the outcome of patients with coronary artery disease. Aim: To assess the influence of cardiac rehabilitation (CR) on endothelial function in patients after ST-segment elevation myocardial infarction (STEMI). Methods: Twenty-nine patients scheduled for CR were included in the study. CR began at least four weeks after STEMI and consisted of 12 or 24 training sessions. Endothelial function assessment was performed before and after CR, using reactive hyperaemia peripheral arterial tonometry. Results: Before the CR, ED was diagnosed in 16 of 29 (55.2%) patients. A total of 25 patients had two assessments of endothelial function: before and after CR. In univariate analysis the factors of negative response of endothelial function to CR were: higher baseline hyperaemia index (lnRHI) (odds ratio [OR] for positive response to CR 0.01; 95% confidence interval [CI] 0.00-0.33; p = 0.01) and higher peak serum troponin I level during index hospitalisation (OR 0.97; 95% CI 0.94-1.00; p = 0.04). The independent, negative predictor of response to CR was lnRHI (OR 0.01; 95% CI 0.01-0.16; p = 0.03). Patients training for 24 sessions (n = 16) had similar lnRHI changes to those of patients training for 12 sessions (n = 9); [0.16 (-0.06)-0.30 vs. 0.10 (0.05-0.15); p = 0.44, respectively]. Conclusions: ED is a frequent abnormality in STEMI survivors. Despite the lack of statistically significant improvement of endothelial function after CR in the analysed group of patients, some factors can influence the efficacy of this type of physical activity. The best effect of CR on endothelial function was observed in patients with baseline ED.