Effect of exercise based cardiac rehabilitation on LV systolic function & exercise stress parameters in patients with ischemic cardiomyopathy post anterior STEMI

Background: Cardiovascular diseases are a leading cause of death worldwide. Multiple meta-analysis have demonstrated the benefit of exercise based cardiac rehabilitation. However, the effect of exercise training on left ventricular (LV) systolic function in patients with ischemic cardiomyopathy has been controversial in the literature. Objective: To study the effect of exercise-based cardiac rehabilitation (EBCR) on left ventricular (LV) systolic function and exercise stress parameters (METs achieved, HR recovery and HR reserve) in post anterior STEMI patients with ischemic cardiomyopathy (EF≤45%). Patients and methods: The study included 50 patients with ischemic cardiomyopathy (Post anterior STEMI successfully treated by 1ry PCI) referred for cardiac rehabilitation unit at Ain Shams University Hospitals. The patients were subjected to 3 months of formal exercise based cardiac rehabilitation. Before the CR program, they were subjected to a symptom-limited exercise test (modified Bruce protocol) to exclude any remaining ischemia and calculate enrolment HR reserve, baseline heart rate recovery in 1st minute and 2nd minute (HRR1 and HRR2). Another symptom-limited exercise test was done post CR program to assess the forementioned exercise parameters after completion of the program. Echocardiography was done at baseline and after completion of the CR program for assessment of LV systolic function by ejection fraction (assessed by 2D Simpson’s method) and peak longitudinal strain of the left ventricle (measured using speckle tracking echocardiography). Results: Exercise-based cardiac rehabilitation was associated with significant improvement in LV systolic function as reflected by significant improvement in Global longitudinal strain (GLS) (P-value = 0.0001) in patients with ischemic heart failure. CR was also associated with improvement in the functional capacity as reflected by the improvement in METs as well as in the HRR and HR reserve (P-value = 0.0001). However, there was no significant change regarding EF before and after cardiac rehabilitation (P-value= 0.4582).