Subsequent in vivo studies confirmed the efficacy of this hydrogel delivery system in reducing infarct size, cardiac fibrosis, and arrhythmia incidence, improving ventricular ejection fraction, and upregulating the expression of key cardiac markers, including α‐actin, Cx43, Ki67, and α‐SMA, and downregulating the expression of TUNEL, ultimately leading to improved cardiac function after MIRI. Here, ACTA1 is linked to cardiac arrhythmia.