Phase 3 Trial Shows Stem Cell Therapy Reduces Heart Failure Risk by 57% After Heart Attack
核心洞察
The PREVENT-TAHA8 phase 3 trial demonstrated that intracoronary infusion of mesenchymal stem cells derived from Wharton's jelly significantly reduced heart failure incidence by 57% in STEMI patients.
At 3 years follow-up, only 5.74% of stem cell-treated patients developed heart failure compared to 16.08% in the standard care group.
The treatment also improved left ventricular ejection fraction by approximately 6% more than standard care and reduced heart failure readmissions by 78%.
Intracoronary infusion of mesenchymal stem cells derived from Wharton's jelly significantly reduced the risk of heart failure in patients recovering from ST-elevation myocardial infarction (STEMI), according to results from the phase 3 PREVENT-TAHA8 trial published in the BMJ.
The randomized controlled trial found that 5.74% of patients who received stem cell therapy developed or were readmitted for heart failure at 3 years, compared to 16.08% of those receiving standard care alone. This represents a 57% reduction in heart failure risk (HR 0.43; 95% CI 0.21-0.89; P=0.024).
Trial Design and Patient Population
The study enrolled 420 patients across three teaching hospitals in Iran, with final analysis including 396 patients (mean age 59 years; 19% women). All participants had undergone percutaneous coronary intervention for acute STEMI with the left anterior descending artery as the infarct-related vessel and had left ventricular ejection fraction (LVEF) below 40%.
More than 60% of patients had a smoking history, 44% had hypertension, and approximately one-third had hypercholesterolemia. Patients were randomized in a 1:2 ratio to receive either intracoronary infusion of allogeneic Wharton's jelly-derived mesenchymal stem cells plus guideline-directed medical therapy, or standard care alone. The stem cell infusion was performed within 3 to 7 days of PCI, with a median follow-up of 33.2 months.
Significant Clinical Benefits Observed
Beyond the primary endpoint of heart failure prevention, the treatment demonstrated substantial benefits across multiple measures. Hospital readmissions for heart failure were reduced by 78% (0.92 vs 4.20 per 100 person-years; HR 0.22; 95% CI 0.06-0.74; P=0.015).
At 6 months, patients in the treatment group showed approximately 6% greater improvement in LVEF compared with the control group (P < 0.001). The composite endpoint of cardiovascular mortality and myocardial infarction was also significantly lower in stem cell-treated patients (HR 0.39; 95% CI 0.19-0.82).
However, no significant differences were observed between groups for individual endpoints of readmission for MI, all-cause mortality, or cardiovascular mortality.
Anti-Inflammatory Mechanism Proposed
Lead author Armin Attar, MD, PhD, from Shiraz University of Medical Sciences, and colleagues suggest the preventive effect may be attributed to the anti-inflammatory properties of mesenchymal stem cells. The findings support results from the DREAM-HF trial, which found that subendocardial transplantation of mesenchymal stem cells in heart failure patients with elevated high-sensitivity C-reactive protein levels reduced reinfarction risk.
"The findings position [mesenchymal stem cells] as a viable adjunctive procedure to mitigate myocardial infarction-induced heart failure," the researchers stated.
Expert Commentary on Clinical Implications
Jay H. Traverse, MD, from Minneapolis Heart Institute, who commented on the study, noted that researchers have evolved their approach based on numerous failed past studies of stem cell therapy. He explained that mesenchymal cells may be superior to bone marrow mononuclear cells for intracoronary therapy, as the latter "often just fly through the heart when you infuse them and go to the spleen and the lungs [without] really doing anything."
Traverse emphasized the economic potential of the therapy, noting that if a single infusion could prevent one heart failure hospitalization, "it would likely pay for itself."
However, he acknowledged challenges facing the field: "Stem cells in general have gotten a bad name in a way because we certainly overpromised, based on the earlier studies, and we have underdelivered dramatically."
Future Research Priorities
The researchers emphasized that multiple research priorities need addressing before this therapy can successfully transition to clinical practice. They stressed the importance of making direct assessment of clinical endpoints the primary objective of future trials, rather than relying on surrogate endpoints as many prior trials have done.
"This is crucial to provide clear evidence" that patients will benefit long-term, the authors noted. They called for further phase I and II studies to identify the most effective stem cell type, isolation technique, and delivery strategy to maximize therapeutic potential in cardiac regeneration.
Traverse noted current limitations in advancing the field: "The issue is that right now what you're seeing is a lot of single sites or small consortiums doing these studies. I'm just not optimistic that cell therapy is going to get front and center again like it was 10 or 15 years ago."
He attributed this partly to the cost of developing therapies and mounting necessary trials, as well as competition from numerous pharmaceutical drugs in development that focus on blocking cytokines and reducing inflammation after myocardial infarction.