WEDNESDAY, Nov. 5, 2025 (HealthDay News) -- Intracoronary infusion of mesenchymal stem cells reduces the risk for heart failure and heart failure readmission among patients with ST-segment elevation myocardial infarction (STEMI) with impaired left ventricular ejection fraction (LVEF), according to a study published online Oct. 29 in The BMJ.Armin Attar, M.D., Ph.D., from Shiraz University of Medical Sciences in Iran, and colleagues examined the effect of intracoronary infusion of allogeneic Wharton's jelly-derived mesenchymal stem cells in a phase 3 randomized clinical trial. Patients with a first STEMI and LVEF <40 percent were enrolled and randomly assigned to receive intervention or standard care within three to seven days of STEMI.The final analysis included 396 patients: 136 in the intervention group and 260 in the control group, with a median follow-up of 33.2 months. The researchers found that intracoronary infusion of mesenchymal stem cells had a preventive effect for incidence of heart failure, readmission to hospital for heart failure, and a composite endpoint of cardiovascular mortality and readmission for myocardial infarction or heart failure (hazard ratios, 0.43, 0.22, and 0.39, respectively). There was no significant effect on readmission to the hospital for myocardial infarction, all-cause mortality, or cardiovascular mortality with the intervention. Compared with the control group, the intervention group showed significantly greater improvement from baseline to six months in the LVEF (β = 5.88).The intervention "highlights the potential of Wharton's jelly-derived mesenchymal stem cells as a valuable adjunctive treatment in primary percutaneous coronary intervention to prevent future adverse events," the authors write.Abstract/Full Text.Sign up for our weekly HealthDay newsletter