Stem cell therapy might improve erectile function in men with ischemic cardiomyopathy, according to recent research in the Journal of Sexual Medicine.
Success may depend on stem cell dose and the type of cells used, however.
Several treatment options are available for the treatment of erectile dysfunction, including medications, vacuum devices, and penile implants. But these treatments are not appropriate for all patients. For example, men who take nitrates for coronary artery disease cannot take phosphodiesterase type 5 inhibitors because of a potentially dangerous drug interaction.
In recent years, scientists have studied stem cell therapy for men with ED. Some experts believe that this approach could do more than just improve symptoms; stem cell therapy might reverse ED itself.
The current study focused on 36 men (median age 66.5 years) who received transendocardial stem cell injections. Data was obtained from three previous studies:
- The Comparison of Allogeneic vs Autologous Bone Marrow–Derived Mesenchymal Stem Cells Delivered by Transendocardial Injection in Patients With Ischemic Cardiomyopathy (POSEIDON trial)
- The Transendocardial Mesenchymal Stem Cells and Mononuclear Bone Marrow Cells for Ischemic Cardiomyopathy (TAC-HFT trial)
- The Dose Comparison Study of Allogeneic Mesenchymal Stem Cells in Patients With Ischemic Cardiomyopathy (TRIDENT study)
All of the participants had ED, scoring less than 25 points on the erectile function domain of the International Index of Erectile Function (IIEF-EF).
Twenty-eight men received stem cell injections (either allogeneic human bone marrow-derived cells or autologous-derived cells). Nine men received 20 million cells, eight men received 100 million cells, and 11 men received 200 million cells.
Eight men received placebo injections.
Median IIEF-EF scores for men in the placebo group changed from 5.5 points at baseline to 3.5 points at a 12-month follow-up point. For those who received stem cells, IIEF scores rose from 5.0 points to 7.0 points.
The researchers found that men who received the highest dose of cells (200 million) and those who received autologous-derived cells had similar significant results: a change from a median of 14 points at baseline to 20 points at the 12-month follow-up visit.
“It is difficult to know the true significance of this difference,” the authors noted. “It is interesting as an exploratory outcome.”
They also analyzed endothelial function in a subgroup of men from the TRIDENT trial. While there were significant improvements in function, “there was no correlation” to IIEF-EF scores.
The authors offered some possible explanations for their results. The participants already had cardiovascular issues, so it’s possible that their ED situation could not be reversed by stem cell therapy.
“Another likely explanation is that not enough stem cells reached corporal tissue to enact an effect,” they added. This might explain why men who received the highest number of stem cells fared better than those who received smaller amounts.
It’s also possible that stem cells do not improve erections in men with vasculogenic ED, they said.
They recommended future research using high cell doses and autologous-derived cells.
The Journal of Sexual Medicine
Ory, Jesse, MD, et al.
“The Effect of Transendocardial Stem Cell Injection on Erectile Function in Men With Cardiomyopathy: Results From the TRIDENT, POSEIDON, and TAC-HFT Trials”
(Full-text. Published online: February 11, 2020)