Mitochondrial Dysfunction in Cardiomyopathy and Heart Failure: From Energetic Collapse to Therapeutic Opportunity

The heart's relentless contractile activity depends critically on mitochondrial function to meet its extraordinary bioenergetic demands. Mitochondria, through oxidative phosphorylation, not only supply ATP but also regulate metabolism, calcium homeostasis, and apoptotic signaling, ensuring cardiomyocyte viability and cardiac function. Mitochondrial dysfunction is a hallmark of cardiomyopathies and heart failure, characterized by impaired oxidative phosphorylation, excessive production of reactive oxygen species (ROS), dysregulated calcium handling, and disturbances in mitochondrial dynamics and mitophagy. These defects culminate in energetic insufficiency, cellular injury, and cardiomyocyte death, driving heart disease progression. Diverse cardiomyopathy phenotypes exhibit distinct mitochondrial pathologies, from acute ischemia-induced mitochondrial collapse to chronic remodeling seen in dilated, hypertrophic, restrictive, and primary mitochondrial cardiomyopathies. Mitochondria also orchestrate cell death and inflammatory pathways that worsen cardiac dysfunction. Therapeutic strategies targeting mitochondrial dysfunction, including antioxidants, modulators of mitochondrial biogenesis, metabolic therapies, and innovative approaches such as mitochondrial transplantation, show promise but face challenges in clinical translation. Advances in biomarker discovery and personalized medicine approaches hold promise for optimizing mitochondrial-targeted therapies. Unlike previous reviews that examined these pathways or interventions individually, this work summarizes insights into mechanisms with emerging therapeutic strategies, such as SGLT2 inhibition in HFpEF, NAD⁺ repletion, mitochondrial transplantation, and biomarker-driven precision medicine, into a unified synthesis. This framework underscores the novel contribution of linking basic mitochondrial biology to translational and clinical opportunities in cardiomyopathy and heart failure. This review synthesizes the current understanding of mitochondrial biology in cardiac health and disease, delineates the molecular mechanisms underpinning mitochondrial dysfunction in cardiomyopathy and heart failure, and explores emerging therapeutic avenues aimed at restoring mitochondrial integrity and improving clinical outcomes in cardiac patients.