Impact of exercise training on myocardial contractile functions assessed by cardiac magnetic resonance in post-myocardial infarction patients.

Background: Improvement of functional capacity and mortality reduction in post-MI patients were found to be associated with regular exercise training. The cardiac magnetic resonance (CMR) is considered the most accurate non-invasive modality in quantitative assessment of left ventricular (LV) volumes and systolic functions. Our main objective was to investigate the impact of exercise training on LV systolic functions in patients post anterior MI using CMR. 32 patients on recommended medical treatment 4 week after having a successful primary PCI for an anterior MI were recruited, between May 2018 and May 2019. They were divided into two groups, training group (TG): 16 assigned to a 12 week exercise training program and control group (CG): 16 who received medical treatment without participating in the exercise training program. Treadmill exercise using modified Bruce protocol was done to TG before and after the training program in order to record the resting and maximum HR, metabolic equivalent (MET), and calculate HR reserve. CMR was performed for all patients 4 weeks after PCI and was repeated after completion of the study period to calculate ejection fraction (EF), left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and wall motion score index (WMSI).

Results: 100% were males. 6 patients from CG dropped during follow-up, no statistically significant difference between the two groups regarding age, BMI, smoking status, hypertension, diabetes mellitus and dyslipidemia. Using the CMR, the TG showed significant improvement in EF (36.6 ± 14.2% to 43.1 ± 12.4%; P < 0.001) and WMSI (2.03 ± 0.57 to 1.7 ± 0.49; P < 0.001), without statistically significant change in LV volumes. Regarding CG no significant changes in EF, WMSI, LV volumes were found. There was significant improvement in EF and WMSI change before and after study in TG vs. CG [6.5 (2.3-9.0) vs. - 2.0 (- 6.8 to 1.3), P value < 0.001] and [- 0.3 (- 0.5 to 0.1) vs. 0.1 (- 0.1 to - 0.5), P value 0.001] respectively.

Conclusions: 12 weeks of exercise training program in post-MI patients have a favorable impact on LV global and regional systolic functions without adversely affecting LV remodeling (as assessed by CMR).