Abstract
Cardiac resynchronization therapy (CRT) is a cornerstone intervention for patients with heart failure (HF) and electrical dyssynchrony, improving quality of life, functional capacity, and survival. Beyond mechanical synchrony, mounting evidence suggests CRT exerts systemic and myocardial cardiometabolic benefits. CRT acutely enhances mechanical efficiency and shifts substrate utilization toward greater oxidation of fatty acids and ketones, effects that correlate with long-term reverse remodeling on cardiac magnetic resonance imaging. Earlier metabolomic profiling demonstrated that CRT normalizes circulating energy metabolites, improving Krebs cycle intermediates and substrate balance between glucose and lipids, while baseline metabolite patterns may differentiate responders from non-responders. These metabolic adaptations accompany favorable changes in diastolic performance, right ventricular function, and ventriculo-arterial coupling. In parallel, improved splanchnic perfusion and reduced congestion may ameliorate gut dysbiosis and endotoxemia, mitigating systemic inflammation. Collectively, these findings position CRT as a therapy capable of both mechanical and metabolic restoration in advanced HF. In this review, we discuss the emerging data on how CRT reconditions myocardial energy metabolism, influences ventricular-arterial interactions, and modulates peripheral and gut-derived metabolic pathways.