A study published in Stem Cells Translational Medicine showed that treating heart patients with mesenchymal stem cells does not increase their risk for irregular heart beat and instead improved the patients’ cardiac conditions.

Previous studies have shown that stem cells have the potential to repair the damage caused by heart disease, but there was speculation that some stem cells could worsen the condition in the same way that some anti-arrhythmia drugs do.

“This could be an important breakthrough for many heart patients, as proarrhythmia – which is a new or more frequent occurrence of pre-existing arrhythmia – unfortunately can be a side effect of some of the drugs we’re using to treat these patients,” lead author Dr. Raul Mitrani said in prepared remarks.

The team of researchers analyzed the data from 88 patients enrolled in 2 clinical trials evaluating the potential of mesenmchymal stem cells in treating ischemic cardiomyopathy.

A year after the patients began treatment, the patients who received mesenchymal stem cells showed no signs of arrythmia.

“We were encouraged by what we saw,” Mitrani said. “Even better, in a group of patients with low ventricular ectopy burden – what some call ‘heart hiccups’ or ‘skipped beats’ – there were definite signs of improvement while in the BMC and placebo groups, no similar signal for improvement was noted. This leads us to believe that prospective studies might clarify the role of MSCs to reduce ventricular arrhythmias.”

“By combining data from 2 studies, the authors were able to study this question in 1 of the largest groups of patients to date,” the journal’s editor-in-chief, Anthony Atlala, added. “These findings are important because they emphasize the need for further large prospective studies to evaluate the anti-arrhythmic potential of mesenchymal and other newer cell-based therapies.”