Erectile dysfunction is almost as strong a predictor of heart disease as smoking or family history, according to a report published last week in The Journal of the American Medical Association.

Researchers studied 3,816 men with erectile dysfunction and 4,247 men with no dysfunction, and they tracked the incidence of angina, heart attack, arrhythmias, stroke and other heart problems over seven years. Men who reported erectile dysfunction before or during the study had a 45 percent increased risk of a cardiovascular event compared with men who never reported the problem.

''Erectile dysfunction is treatable,'' said Dr. Ian M. Thompson, the lead author of the report and chairman of urology at the University of Texas Health Science Center at San Antonio. ''It may be the event that gets a man in to see a doctor. That patient should ask his physician: 'I used to smoke. My dad died of a heart attack. Now I have E.D. Do I need further evaluation?' Then the doctor has additional responsibilities to think about cardiac illness as well.''

The link between erectile dysfunction and cardiovascular disease, the authors write, has previously been established, but the magnitude of the effect has not been known until now.

The authors acknowledge that the results depend on patient reports of erectile dysfunction that may be difficult to assess and that they did not collect data on blood pressure medications or medications for erectile dysfunction, which may have altered the results.

Still, the association held even after controlling for smoking, cholesterol level, family history and other factors.