Platelets as Central Modulators of Post-Cardiac Arrest Syndrome: Mechanisms and Therapeutic Implications

Post-cardiac arrest syndrome (PCAS) remains a major cause of mortality and neurological impairment following successful resuscitation, yet the mechanisms linking global ischemia-reperfusion injury to microvascular and systemic dysfunction are not yet completely understood. While prior work has focused on inflammation, endothelial injury, and circulatory collapse, the central role of platelets in coordinating these pathological processes has not been comprehensively examined. This review provides the first integrated framework positioning platelets as core modulators, rather than secondary participants, in PCAS pathophysiology. We synthesize emerging evidence demonstrating that ischemia and reperfusion transform platelets into potent thromboinflammatory effectors through oxidative stress, DAMP-mediated pattern recognition signaling, and mitochondrial dysfunction. Hyperactivated platelets drive cerebral microthrombus formation, coronary no-reflow, and peripheral organ hypoperfusion, while platelet-leukocyte aggregates, neutrophil extracellular traps, and platelet-derived microparticles amplify systemic inflammation and endothelial injury. We further highlight the clinical significance of dynamic platelet dysfunction in coagulopathy, prognostication, and responses to post-arrest therapies including targeted temperature management and ECMO. Finally, we outline a novel, platelet-centered therapeutic paradigm, emphasizing selective interventions, such as GPVI inhibition, P-selectin blockade, FXI/XIa inhibition, and NETosis modulation, that target pathological platelet activity while preserving essential hemostatic function. In this review, by reframing platelets as the central determinants of PCAS, we report new mechanistic insights and therapeutic opportunities that are complementary to the existing post-arrest strategies and have the potential to improve survival and neurological outcomes after cardiac arrest.