Benefits of lifelong exercise training on left ventricular function after myocardial infarction

Background Endurance exercise training induces cardio-protective effects, but athletes are not exempted from a myocardial infarction. Evidence from animal studies suggests that exercise training attenuates pathological left ventricular remodelling following myocardial infarction. We tested the hypothesis that lifelong exercise training is related to attenuated pathological left ventricular remodelling after myocardial infarction as evidenced by better left ventricular systolic function in veteran athletes compared to sedentary peers. Design This was a cross-sectional study. Methods Sixty-five males (606 years) were included and allocated to four groups based on lifelong exercise training volumes: (a) athletes (n=18), (b) post-myocardial infarction athletes (athletes+myocardial infarction, n=20), (c) sedentary controls (n=13), and (d) post-myocardial infarction controls (sedentary controls+myocardial infarction, n=14). Athletes were lifelong (20 years) highly physically active (30 metabolic equivalent of task (MET)-h/week), whereas sedentary controls did not meet the exercise guidelines (<10 MET-h/week) for the past 20 years. left ventricular systolic function, diastolic function and wall strain were measured using echocardiography. Results Cardiac enzyme markers (creatine-kinase, creatinine, aspartate transaminase and lactate dehydrogenase) following myocardial infarction and infarct location did not differ between athletes+myocardial infarction and sedentary controls+myocardial infarction. Left ventricular ejection fraction was significantly higher in athletes (61%+/- 4), athletes+myocardial infarction (58%+/- 4) and sedentary controls (57%+/- 6) compared to sedentary controls+myocardial infarction (51%+/- 7; p<0.01). Left ventricular circumferential strain was superior in athletes (-19% (-21% to -17%), athletes+myocardial infarction (-16% (-20% to -12%)), and sedentary controls (-15% (-18% to -14%) compared to sedentary controls+myocardial infarction (-13% (-15% to -8%), p<0.01). Diastolic function parameters did not differ across groups. Conclusion These findings suggest that lifelong exercise training may preserve left ventricular systolic function and possibly attenuates or minimises the deleterious effects of pathological post-myocardial infarction left ventricular remodelling in veteran athletes.