Evaluation by Dipirydamole MRI of the effects of cardiac rehabilitation after myocardial infarction

Background: The effects of exercise training (ET) on myocardial perfusion after myocardial infarction have been well studied with scintigraphy whereas cardiac MRI seems a better technique which was not used yet in the literature in this indication. Methods: 11 patients after a first myocardial infarction were left again in 2 groups: a 20 session-ET program (T, n=6) and a control group (C, n=5). All patients underwent a dipirydamole MRI and a cardiopulmonary test at entry and after 3 months. Results At 3 months, improvements in work capacity (P < 0,05), peak VO2 (P < 0,05) were observed in T but not in C. Ejection fraction and left ventricular (LV) volumes were unchanged in T and C. Myocardial perfusion assessed by MRI was comparable at rest and after dipirydamole in each group. The recuperation of the segmentary kinetics was inversely proportional to the delayed enhancement given by MRI and was better for T than for C (P < 0,02). Conclusions: This is a preliminary study. Cardiac MRI makes it possible to apprehend perfusion in a reliable and reproducible way. ET has no detrimental effects on LV volumes and function; rather, it improves recovery of infarcted segments