Aging poses obstacles to the functionality of human mesenchymal stem cells (MSCs), resulting in a notable decline in their valuable contribution to myocardial infarction (MI). MicroRNAs (miRNAs) play a pivotal role in governing MSC aging; nonetheless, the specific mechanisms remain puzzling. This research delved into the value of miR-873-5p in the management of MSC aging and investigated whether the restraint of miR-873-5p could regenerate aged MSCs (AMSCs), thereby enhancing their healing success for MI. In this study, MSCs were isolated from both young donors (referred to as YMSCs) and aged donors (referred to as AMSCs). The senescence status of these MSCs was evaluated through the application of age-related beta-galactosidase (SA-beta-gal) staining. Following this assessment, the MSCs, including those treated with anti-miR-873-5p-AMSCs, were then transplanted into the hearts of Sprague-Dawley rats experiencing acute myocardial infarction. Increasing miR-873-5p levels in YMSCs resulted in elevated cellular aging, whereas reducing miR-873-5p expression decreased aging in AMSCs. Mechanistically, miR-873-5p inhibited autophagy in MSCs through the AMPK signaling pathway, leading to cellular aging by suppressing the Cab39 expression. Partial alleviation of these effects was achieved by the administration of the autophagy inhibitor 3-methyladenine. Grafting of anti-miR-873-5p-AMSCs, by enhancing angiogenesis and bolstering cell survival, led to an improvement in cardiac function in the rat model, unlike the transplantation of AMSCs. miR-873-5p which serves as a pivotal element in mediating MSC aging through its regulation of the Cab39/AMPK signaling pathway. It represents an innovative target for revitalizing AMSCs and enhancing their heart-protective abilities.