Results from a Phase III clinical trial have shown that patients who received a stem cell therapy within a week of a heart attack had a significantly lower risk of developing heart failure within the next three years compared to patients who received the standard care. Based on these findings, published today in the BMJ journal, the researchers propose stem cell therapy as an add-on treatment to prevent future heart failure and related hospital stays in patients at risk.
While deaths due to heart attacks have dropped by nearly 90% over the past 50 years, many survivors go on to develop heart failure further down the line. “Although the management of heart failure is well advanced, preventive measures for heart failure in patients after a myocardial infarction remain underexplored,” write the authors of the study. “Stem cell therapy has emerged as a promising intervention because it can support repair of cardiac tissue and preserve ventricular function.”
Stem cell therapy had previously shown to improve heart function after a heart attack, but no large-scale clinical trial had looked at whether this treatment could significantly reduce the risk of heart failure in this high-risk patient population.
As part of the PREVENT-TAHA8 trial, 136 patients received an infusion of allogeneic mesenchymal stem cells within three to seven days of a heart attack, in addition to the standard care, while 260 patients received the standard care alone. All patients had no previous history of heart disease and had been hospitalized for their first heart attack across three hospitals in Shiraz, Iran. On average, patients were followed for 33 months.
Compared to the control group, patients who received the stem cell therapy saw a 57% reduction in heart failure risk and a 78% lower rate of hospital readmissions due to heart failure. Six months after treatment, those treated with the stem cell therapy showed a significant improvement in heart function.
Conversely, the treatment did not have a statistical effect on the hospital readmission rate due to heart attack, cardiovascular death or death from any cause. These results seem to confirm previous findings from the BAMI clinical trial, one of the largest of its kind, which showed that while an autologous bone marrow cell therapy did not reduce the all-cause mortality rate, the treatment did significantly reduce the rate of hospitalizations due to heart failure during the two years after the initial treatment.
“Mortality remains a complex outcome to affect, and why stem cell therapy has not consistently shown benefit in this domain is not yet clear,” said the authors. “This may be attributed to the requirement for very large sample sizes to detect a mortality effect, or it may reflect the underlying mechanisms of action of stem cells, which may primarily affect functional and reparative pathways rather than directly altering survival.”
The researchers stated that more work will be needed to identify optimal cell types, refine delivery methods, and better understand the underlying mechanisms of action of stem cell therapy. Their hope is that, one day, this treatment could be used in routine clinical practice to prevent complications later on in the journey of patients with heart disease, which remains the leading cause of mortality around the world.
