Heart failure remains a major cause of global morbidity and mortality despite advances in guideline-directed medical therapy. Nanoparticle-based approaches have gained attention as strategies to enhance therapeutic delivery; however, their clinical relevance depends on addressing true pharmacological barriers rather than repackaging existing agents. In this review, we present a conceptual framework to define when nanomedicine provides meaningful therapeutic value in heart failure. We argue that nanotechnology should not be viewed as a replacement for guideline-directed medical therapy, but as an enabling platform for the targeted delivery of potent therapies limited by pharmacokinetic and biodistribution constraints. We summarize the principal nanoparticle platforms used in cardiovascular applications, including lipid-based and polymeric systems, and contextualize their use across key pathophysiological domains in heart failure: TGF-β (transforming growth factor-beta)-mediated fibrosis, IL-1β (interleukin-1 beta) and TNF-α (tumor necrosis factor-alpha)-driven inflammation, reactive oxygen species-mediated injury, regenerative strategies, and gene- and mRNA-based therapies. We propose 3 criteria for translational relevance: (1) a targetable myocardial microenvironment, (2) a therapeutic agent limited by conventional delivery, and (3) a formulation that confers a demonstrable clinical advantage. Although these conditions are met in selected preclinical models, clinical translation remains limited. The field is therefore shifting from an emphasis on delivery feasibility to therapeutic necessity. Nanomedicine is best positioned as a precision adjunct to heart failure therapy-enabling the right therapy to reach the right myocardium at the right time.

Postcardiac arrest syndrome is a complex multisystem disorder that evolves after return of spontaneous circulation and remains a major determinant of morbidity and mortality following out-of-hospital cardiac arrest. Beyond anoxic brain injury and transient myocardial dysfunction, many patients develop a systemic ischemia/reperfusion response with endothelial and microvascular dysfunction, vasoplegia, and immune dysregulation-features that contribute to shock and organ failure. Hemodynamic instability is often mixed with low systemic vascular resistance despite preserved or recovering cardiac output, but management is still largely supportive and centered on achieving a target mean arterial pressure. An increasing understanding of the central role of inflammation, including gastrointestinal barrier disruption, cytokine release, complement activation, nitric oxide-cGMP signaling, and immune phenotypic heterogeneity has prompted evaluation of targeted adjunctive therapies. However, randomized trials of immunomodulators and other vasoactive strategies have yielded mixed results, reflecting biological heterogeneity and limited phenotypic stratification. This review synthesizes contemporary understanding of the inflammatory and hemodynamic mechanisms underpinning postcardiac arrest syndrome, examines current and emerging pharmacologic strategies, and highlights priorities for future investigation, including mechanistic phenotyping, prospective biobanking, and prospective trial requirements to guide more precise management strategies in postcardiac arrest care.