Myocardial strain assessment by 2D Speckle Tracking to evaluate the effect of cardiac rehabilitation in patients with or without heart failure

Abstract

Cardiac rehabilitation improves the subjective condition of the patient, but little is known about associated structural and functional cardiac adaptations specifically the myocardial strain. To evaluate the impact of rehabilitation on structural and functional cardiac parameters using myocardial strain assessment by 2D Speckle Tracking. The study group consisted of 86 patients: 46 with heart failure with optimal medical treatment and 40 patients after acute myocardial infarction. A monocentric cohort study has included all patients who performed a 2-months cardiac rehabilitation program during one year. Clinical characteristics, a resting electrocardiogram, 2-dimensional Doppler echocardiography with tissue Doppler and strain imaging, and an incremental maximal exercise test on a bicycle ergometer were collected before and after the rehabilitation program. Paired Student t-test for comparison and Pearson's correlation coefficient were used for the statistical analysis. Eighty-six patients (46 with heart failure with optimal medical treatment and 40 patients after acute myocardial infarction) were included. Performance capacity was significantly improved after cardiac rehabilitation (Table 1): performance in watts 112 watts (±50) vs. 69.8 watts (±34.5); effort test duration 10.7 min (±4.4) vs. 6.9 min (±3.1) and 6 min walking time 565 m (±127) vs. 496 m (±113). Echographic parameters were also significantly improved: LVFE 52.9% (±13) vs. 46.9% (±12.7), E/E′ 6.7 (±1.54) vs. 7.38 (±2.9). Significant difference of strain before and after cardiac rehabilitation 15.38% (±4.72) vs. 14.12 (±4.79) has been also recorded. BNP level decreased by 29 ng/dL but not statistically significant from baseline. Nonetheless, no significant correlation was found between biological, functional and echocardiographic parameters. Both the performance capacity and left ventricular function on Doppler imaging were significantly improved in the 2 groups after the rehabilitation program in contrast to the BNP level. Strain imaging could be an interesting additional parameter to evaluate the positive response and structural improvement in patients with or without chronic heart failure who are undergoing cardiac rehabilitation.