A new Miller School study found that women and men with a heart muscle disease called non-ischemic dilated cardiomyopathy respond similarly to injections of mesenchymal stem cells (MSCs). In addition, women are more likely than men to have a substantial recovery from this condition because of the smaller size and shape of their left ventricles.
“The issue of sex differences in heart disease is a major issue in cardiology, and these findings have important clinical implications for the ongoing development of cell therapy,” said Joshua M. Hare, M.D., Louis Lemberg Professor of Medicine and founding director of the Interdisciplinary Stem Cell Institute (ISCI) at the University of Miami Miller School of Medicine. “Women with heart disease often don’t respond as well to treatment as men, and may have worse outcomes. There are also disparities in clinical research, as women have been underrepresented in clinical trials through the years – an issue that must be taken into consideration in designing future trials.”
Dr. Hare was the senior author of the study, “The Impact of Patient Sex on the Response to Intramyocardial Mesenchymal Stem Cell Administration in Patients with Non-Ischemic Dilated Cardiomyopathy,” published online recently in Cardiovascular Research. Dilated cardiomyopathy is an acquired or hereditary disease that reduces the heart’s ability to pump blood because the left ventricle is enlarged and weak, a condition that can lead to heart failure.
Miller School co-authors were Raul D. Mitrani, M.D., associate professor of medicine and director of clinical cardiac electrophysiology; Ivonne H. Schulman, M.D., professor of clinical medicine and current program director, Translational and Clinical Studies of Acute Kidney Injury, National Institutes of Health; Angela C. Rieger, M.D., M.Sc.; Makoto Natsumeda, M.D.; Bryon A. Tompkins, M.D.; Monisha N. Banerjee, M.D.; Courtney Premer, Ph.D.; Aisha Khan, M.Sc., M.B.A.; Krystalenia Valasaki, M.Sc.; Bettina Heidecker, M.D., Ph.D.; Alejandro Mantero, Ph.D.; and Wayne Balkan, Ph.D. Victoria Florea, M.D., a former Miller School scientist who is now associate director of clinical science at MyoKardia in South San Francisco, was the lead author.
The new study examined outcomes for 24 male and 10 female patients who received MSCs in POSEIDON-DCM, a randomized clinical trial led by Dr. Hare whose results were published in 2017. The research team examined patient outcomes, such as improvements in the function of endothelial cells that control vascular relaxation, ejection fractions, the percentage of blood leaving the left ventricle each time it contracts and functional parameters including the walk distance capacity or quality of life parameters.
“We found men and women improved to the same extent, in contrast to other types of therapy that typically show better outcomes in men,” said Dr. Hare. “While the response to treatment was similar, the women trial participants tended to have better outcomes because of the smaller size of their hearts. In fact, more women than men ended up with a full cure.”
This study corroborates that the sex of the patient plays an important role in disease progression, said Dr. Rieger. “Having a subset of patients that can return to recovered contractility of the heart could translate into fewer complications and mortality in the short term and probably long term,” she said. “However, this still needs to be confirmed in a specified clinical trial. We are also looking at other parameters, such as genetic variants, and combining this with precision medicine to optimize therapy.”
Summarizing the results, Dr. Hare said, “This study is the first of its kind to demonstrate that MSC therapy improves a variety of parameters in non-ischemic dilated cardiomyopathy irrespective of patient sex.”