PREVENT-TAHA8: Post-MI Intracoronary Stem Cells May Lower HF Risk After STEMI

An intracoronary infusion of stem cells after PCI may benefit some STEMI patients as an adjunctive treatment in reducing the incidence of heart failure (HF), according to results from the PREVENT-TAHA8 study.

At 3 years, 5.74% of patients who received an infusion of mesenchymal cells derived from Wharton’s jelly—the mucous connective tissue of the umbilical cord that is rich in stem cells—developed or were readmitted to hospital for HF, as compared to 16.08% of those treated with standard care.

In the paper, published October 29, 2025, in the BMJ, Armin Attar, MD, PhD (Shiraz University of Medical Sciences, Iran), and colleagues say “the findings position [mesenchymal stem cells] as a viable adjunctive procedure to mitigate myocardial infarction-induced heart failure.”

They suggest that the preventive effect may be attributed to the anti-inflammatory properties of these stem cells and supports results from the DREAM-HF trial, a study that found a subendocardial transplantation of mesenchymal stem cells in HF patients with elevated high-sensitivity C-reactive protein levels reduced the risk of reinfarction.

PREVENT-TAHA8 also contributes valuable information on the potential impact of stem cell therapy on left ventricular ejection fraction, they add. At 6 months, patients in the treatment group had about a 6% greater improvement in LVEF compared with the standard care control group (P < 0.001).

Jay H. Traverse, MD (Minneapolis Heart Institute, MN), who commented on the study, said researchers have evolved their thinking based on numerous failed past studies of stem cell therapy.

Mesenchymal cells, he told TCTMD, may be the better option for intracoronary therapy than bone marrow mononuclear cells, which are easy to obtain but “often just fly through the heart when you infuse them and go to the spleen and the lungs [without] really doing anything.”

Like the researchers, Traverse said the anti-inflammatory hypothesis makes sense, and if larger studies can replicate this work, it could lead to a potentially easily-used adjunct to contemporary medical therapies.

“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,” he added. While PREVENT-TAHA8 may not move the needle much at this time, Traverse said it could fuel hope that researchers in this area have had for years of being able to provide a safe and economical way of offering stem cell therapy. If a single infusion could be shown to prevent one HF hospitalization, for example, it would likely pay for it itself, he added.

PREVENT-TAHA8

Attar and colleagues randomized 396 patients (mean age 59 years; 19% women) at three teaching hospitals in Iran. More than 60% had a smoking history, 44% had hypertension, and about one-third had hypercholesterolemia. All had undergone PCI for acute STEMI with the LAD as the infarct-related artery and had LVEF rates below 40%. Patients in the intervention group had the intracoronary procedure to infuse the stem cells within 3 to 7 days of PCI in addition to the guideline-directed medical therapy (GDMT), while the control patients received GDMT alone after PCI.

The incidence of HF was significantly lower in those randomized to the stem-cell therapy (2.77 vs 6.48 per 100 person-years; HR 0.43; 95% CI 0.21-0.89) as was the incidence of HF readmissions (0.92 vs 4.20 per 100 person-years; HR 0.22; 95% CI 0.06-0.74). The composite endpoint of cardiovascular mortality and MI also was significantly lower in those treated with stem cells (HR 0.39; 95% CI 0.19-0.82).

No differences were seen between the groups for the individual endpoints of readmission for MI, all-cause mortality, or CV mortality.

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 Jay H. Traverse

Attar and colleagues say the findings “underscore the need to conduct further phase I and II studies aimed at identifying the most effective stem cell type, isolation technique, and delivery strategy to maximize the therapeutic potential of mesenchymal stem cells in cardiac regeneration.”

However, they also note that among the multiple research priorities needing to be addressed before this therapy can transition successfully to the bedside is making direct assessment of clinical endpoints the primary study objective of future trials, rather than surrogate endpoints as many prior trials have done. This, they add, “is crucial to provide clear evidence” that patients will benefit in the long term.

“The issue is that right now what you're seeing is a lot of single sites or small consortiums doing these studies,” Traverse said. “I'm just not optimistic that cell therapy is going to get front and center again like it was 10 or 15 years ago.”

Part of the reason for that, he added, is both the cost to develop the therapies and to mount the needed trials, as well as the fact that blocking cytokines and reducing inflammation after MI is the focus of numerous drugs in the pharmaceutical pipeline.

“There’s also still some skepticism out there, and I think it’s fairly well founded,” he said.