Link between atherosclerosis, erectile dysfunction strengthened in imaging study
NEW ORLEANS — An advanced imaging study using fluorine-18 sodium fluoride PET determined that there is a relationship between atherosclerosis and erectile dysfunction, researchers reported at the American College of Cardiology Scientific Session.
In the study of 437 men with prostate cancer (mean age, 67 years) who underwent a series of fluorine-18 sodium fluoride PET scans, each increment of a measure of atherosclerosis in the penile arteries corresponded to an increased likelihood of erectile dysfunction, according to the researchers, who simultaneously published their findings in the Journal of the American College of Cardiology.
“When we looked at the scans, we saw something striking,” Cardiology Today Editorial Board Member Jagat S. Narula, MD, PhD, MACC, associate dean for global health at Icahn School of Mount Sinai and professor of medicine and Philip J. and Harriet L. Goodhart Chair in Cardiology and director of the Cardiovascular Imaging Program in Mount Sinai’s Zena and Michael A. Wiener Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Center for Cardiovascular Health, said in an interview. “We saw there was some kind of a penile uptake of sodium fluoride. When we looked at the cross section, we found that it was not a product of excretion; on both sides of the urethra, there were areas lighting up that coincide with the bulbar arteries of the penis. These are the areas that fill in with blood to bring on an erection. As long as you retain blood in there with no leak, the erection will be maintained; failure to retain blood there leads to erectile dysfunction.”
A link revealed
That led the team to hypothesize that atherosclerosis was present in the areas lit up by sodium fluoride, Narula said.
“If there is some form of atherosclerosis in these arteries, there will be a narrowing, and if there is a narrowing, the blood flow will be reduced, and there will be less blood in the cavernous areas that should be filled with blood to maintain an erection,” he said. “This was a serendipitous finding.”
Among the cohort, 76.9% of men had prevalent erectile dysfunction, 13.7% had incident erectile dysfunction within 1 year and 9.4% had normal erectile function.
Maximum standard uptake value (SUVmax) was higher in the prevalent group (median, 1.88; interquartile range [IQR], 1.67-2.16) and in the incident group (median, 1.86; IQR, 1.72-2.08) than in the normal group (median, 1.42; IQR, 1.25-1.54; P < .001), Narula and colleagues found.
After adjustment for other risk factors, each 0.5-U increment of SUVmax was associated with an OR of 25.2 (95% CI, 9.5-67) for prevalent or incident erectile dysfunction (area under the receiver operating curve, 0.91; 95% CI, 0.88-0.94).
“Many experts believe that, in the majority of cases, atherosclerosis is the most important cause underlying erectile dysfunction,” Narula told Cardiology Today. “But until now, there had not been a way of looking at it. In the past, people had been looking by CT at calcification in the arteries that give rise to the bulbar arteries, and some have conducted angioplasty of those arteries, but no one had ever been able to see the atherosclerosis in the penile artery. We suspect the sodium fluoride uptake in the penile arteries represents atherosclerosis in these arteries.”
An implication, he said, is that controlling risk factors for atherosclerosis may be able to prevent erectile dysfunction in the same way it prevents heart disease.
“One important message of this study is going to be that we must have a better lifestyle if we want to prevent erectile dysfunction,” Narula said.
The next step, he said, is to use fluorine-18 sodium fluoride PET to image the penile arteries of men without prostate cancer to see whether the association applies to a wider population.
‘A novel tool’
In a related editorial published in JACC, Ahmed Tawakol, MD, associate director of nuclear cardiology, co-director of the Cardiac MR PET CT Program and director of the Integrative Bio-Imaging Program at Massachusetts General Hospital, and associate professor of medicine at Harvard Medical School, and colleagues wrote that the findings “raise the possibility that the process of penile arterial microcalcification may contribute to the development of [erectile dysfunction]” and “highlights [sodium fluoride] imaging as a novel tool that could be used to study vasculogenic [erectile dysfunction]: to enrich [erectile dysfunction] trials by identifying individuals at highest risk or to be used as a surrogate marker for predicting treatment response.” – by Erik Swain
Nakahara T, et al. Abstract 1137-468. Presented at: American College of Cardiology Scientific Session; March 16-18, 2019; New Orleans.
Disclosures: The authors report no relevant financial disclosures.