Men with erectile dysfunction were more likely than other men to experience chest pain, a heart attack or a stroke during the next seven years, the study found.
The results suggest that men who see their doctors for impotence drugs also should consider getting screened for heart disease, said study co-author Dr. Ian Thompson of the University of Texas Health Science Center at San Antonio.
"There are many men who die suddenly of a heart attack, never having seen a physician and never having their cardiovascular risk assessed," Thompson said. "Some of these men may never have had a symptom of cardiovascular disease."
The study appears in Wednesday's Journal of the American Medical Association.
The connection isn't new. Researchers already understood that heart disease and erection problems share risk factors, including obesity, smoking, diabetes, high blood pressure and physical inactivity.
But the study is the first to look at a large group of healthy men and monitor them over time, Thompson said. Researchers used data on 8,063 men without pre-existing heart conditions who participated in a study on prostate cancer prevention.
The researchers found erectile dysfunction to be almost as good a predictor for cardiovascular disease as a family history of heart attack.
But it wasn't a perfect predictor. In the group of men that had erection problems, 11 percent went on to experience a cardiovascular event. In the group with no erectile complaints during the study period, 6 percent still went on to have a cardiovascular event.
The study had limitations. It didn't use the standard questionnaire used by researchers to measure erectile dysfunction and it relied on patients' own reports of heart problems, rather than their medical records, said Dr. Elizabeth Barrett-Connor of the University of California San Diego, who was not involved in the study.
"But I think their results are right," she said. "I think it's good this article is being published in a major journal. It may get more people to improve their lifestyle, if nothing else."