Two Routes for Removing Unhealthy Mitochondria: Degradation and Secretion

Mitochondria are highly dynamic, double-membraned organelles that generate the majority of ATP in cardiomyocytes while supporting cellular homeostasis and signal transduction. Accumulation of dysfunctional mitochondria can promote cardiomyocyte loss, impair contractile function, and ultimately lead to myocardial damage. To preserve mitochondrial integrity, cardiomyocytes rely on multilayered quality control mechanisms to remove defective mitochondria. Two major routes have emerged for this process: degradation, primarily via autophagy, and secretion via extracellular vesicles. This review summarizes the mechanisms of mitochondrial degradation and secretion in the heart and highlights their contributions to cardiac disease progression and potential as therapeutic targets.