Engineered cardiac patches from hiPSC-derived cardiomyocytes.

BACKGROUND: Heart failure remains a leading global cause of morbidity and mortality, with limited capacity for myocardial regeneration following infarction. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have become a promising therapeutic resource due to their scalability, differentiation potential, and immunologic adaptability. Engineered cardiac patches, three-dimensional constructs of hiPSC-CMs combined with supporting cells and scaffolds, offer a strategy to deliver organized myocardium directly to injured hearts, overcoming the limitations of cell injection therapies. SCOPE OF REVIEW: This review synthesizes evidence from 2010 to early 2025, spanning rodent, porcine, and non-human primate models, as well as the first clinical trials of hiPSC-CM patches. We highlight recent advances in maturation protocols, vascularization strategies, and scaffold engineering, while discussing two distinct translational paradigms: short-term paracrine support versus long-term remuscularization under sustained immunosuppression. RESULTS: Preclinical studies show that engineered patches improve graft survival, with engraftment rates ranging from 5 to 15%, alongside enhanced vascularization, electrical coupling, and left ventricular function. In large animal models, patches scaled to clinically relevant sizes achieved durable integration and improved hemodynamics. Of note, arrhythmogenic risk was lower than in intramyocardial injection models. Early human trials in Japan and Germany confirm feasibility and safety, with preliminary evidence of efficacy, including preliminary evidence of improved left ventricular ejection fraction and upgrades in NYHA functional class. Immunogenicity, graft maturation, and manufacturing scalability remain key hurdles, though innovations such as gene-edited hypoimmunogenic lines, multipronged maturation strategies, and bioreactor-based production offer potential solutions. CONCLUSIONS: Engineered hiPSC-CM cardiac patches represent a rapidly advancing frontier in regenerative cardiology. While early data indicate technical feasibility and measurable functional benefits, broader adoption will depend on resolving challenges of immune compatibility, arrhythmia prevention, and large-scale manufacturing. With coordinated progress in science, engineering, and regulation, cardiac patches may evolve into a transformative therapy for heart failure.