Key result
Exercise-based cardiac rehab is linked to ~20% better ventricular-arterial coupling alongside improved LV efficiency.
Why the study?
The effect of cardiac rehabilitation on left ventricular mechanical efficiency and ventricular-arterial coupling in unselected heart failure patients has not been studied.
Does exercise-based cardiac rehabilitation improve ventricular-arterial coupling and left ventricular mechanical efficiency in patients with systolic heart failure?
Does exercise-based cardiac rehabilitation improve ventricular-arterial coupling and left ventricular mechanical efficiency in patients with systolic heart failure?
Absolute Event Rate: 0.67% vs 0.56%
p-value: p=0.02
Exercise-based cardiac rehabilitation significantly improves surrogate markers of cardiac mechanics, specifically ventricular-arterial coupling and left ventricular mechanical efficiency, in patients with systolic heart failure.
CR effects on LV efficiency/VAC in unselected HF remain unclear; leaves open whether these metrics add value beyond peak VO2.
BACKGROUND: Success of cardiac rehabilitation (CR) is generally assessed by the objective improvement in peak volume of inhaled oxygen (VO2) measured by cardiopulmonary exercise test (CPX). However, cardiac mechanical efficiency and ventricular-arterial coupling (VAC) are the other important dimensions of the heart failure pathophysiology, which are not included in CPX-derived data. The effect of cardiac rehabilitation on left ventricular (LV) efficiency or VAC in unselected heart failure patients has not been studied thus far. METHODS AND RESULTS: Thirty patients with an ejection fraction of ≤45% were recruited for 20 sessions of exercise-based CR. Noninvasive LV pressure-volume loops were constructed and VAC was calculated with the help of applanation tonometry and echocardiography before and after CR. VAC showed an improved mechanical efficiency profile and increased significantly from 0.56±0.18 to 0.67±0.21 (P=0.02). LV mechanical efficiency improved from 43.9±9.1% to 48.8±9.1% (P=0.01). The change in peak VO2 was not in a significant correlation with the change in VAC (r=-0.18; P=0.31), mechanical efficiency (r=-0.16, P=0.39), or the change in ejection fraction (r=-0.07; P=0.68). CONCLUSIONS: CR is associated with an improvement in VAC and LV mechanical efficiency in heart failure patients. Further studies are needed to determine the incremental value of VAC and mechanical efficiency over CPX-derived data in predicting clinical outcomes.
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Aslanger et al. (2015) studied Systolic Heart Failure (n=30). Exercise-based cardiac rehabilitation vs. Pre-rehabilitation baseline was evaluated on Ventricular-arterial coupling (VAC) (p=0.02). Exercise-based cardiac rehabilitation significantly improved ventricular-arterial coupling (from 0.56 to 0.67; P=0.02) and LV mechanical efficiency (from 43.9% to 48.8%; P=0.01).