Sex and the Heart: New Guidelines for Men

  May 1, 2002

Reprinted with the permission from Harvard Men's Health Watch (May 2002), published by Harvard Medical School  (www.health.harvard.edu). Copyright 2002 by the President and Fellows of Harvard College.

All Rights reserved.

It's a familiar dilemma: A man who has had a heart attack is eager to return to normal sexual activity, his wife is worried and reluctant, and his doctor is caught in the middle. Though the scenario is common, the next act has been harder to predict, as doctors have struggled to formulate the best response. To help reconcile conflicting approaches, a group of experts from around the world gathered in Princeton, New Jersey, for the International Consensus Conference on Sexual Activity and Cardiac Risk. The guidelines they issued will help men decide when sex is safe for them.

Sex as Exercise

Disappointingly, perhaps, people seem to spend more energy thinking and talking about sex than on the act itself. During sexual intercourse, a man's heart rate rarely gets as high as 130 beats a minute, and his systolic blood pressure (the higher number, recorded when the heart is pumping blood) nearly always stays under 170. All in all, average sexual activity ranks as mild to moderate in exercise intensity. It uses oxygen three and a half times faster than sitting quietly, which is about the same as doing the foxtrot or raking leaves. Sex burns about 5 calories a minute; that's 4 more than a man uses watching TV, but it's about the same as walking the course to play golf. If a man can walk up two or three flights of stairs without difficulty, he should be in good enough shape for sex.

Sex as Sex

Raking leaves may increase a man's oxygen consumption, but it probably won't get his motor running. Sex, of course, is different, and the excitement and stress might well pump out extra adrenaline. Both mental excitement and physical exercise increase adrenaline levels and can trigger heart attacks and arrhythmias, abnormalities of the heart's pumping rhythm. Can sex do the same? In theory, yes. But in practice it's really very uncommon, at least during conventional sex with a familiar partner.

Careful studies show that fewer than 1 of every 100 heart attacks are related to sexual activity, and for fatal arrhythmias the rate is just 1 in 200. Put another way, for a healthy 50-year-old man, the risk of having a heart attack in any given hour is about one in a million; sex doubles the risk, but it's still just two in a million. For men with heart disease, the risk is ten times higher, but even for them, the chance of suffering a heart attack during sex is just twenty in a million. Those are pretty good odds, but the new guidelines suggest that it may be possible to make them even better.

Rating the Risk

The Consensus Conference arrived at a classification system based on a man's cardiac risk factors as well as his personal history of heart disease. In addition to age, the major risk factors included high blood pressure, diabetes, obesity, cigarette smoking, abnormal blood cholesterol levels, and a sedentary lifestyle. Using these considerations, men can be divided into one of three risk categories.

Low risk. Most men will fall into this group. Included are men with two or fewer major cardiac risk factors, men with well-controlled hypertension or mild, stable angina, men who have had successful angioplasties or coronary artery bypass operations, and even men who are as little as 6√8 weeks out from heart attacks. Men with mild heart valve disease or mild congestive heart failure are also considered at low risk.

According to the conference, sex should be safe for low-risk men; as a result, they don't need special testing or extra precautions.

Moderate risk. This category includes men with three or more major cardiac risk factors, men with moderately severe but stable angina, and men who are 2√6 weeks past a heart attack. Also included are men with moderately severe congestive heart failure and those with evidence of atherosclerosis beyond the heart, such as previous strokes or peripheral artery disease.

The conference recommends caution for men at moderate risk, suggesting that they avoid sex until they have had a detailed cardiovascular evaluation, usually including a stress test and an echocardiogram. Men who pass these tests with flying colors can be reclassified as low risk, but any problems that show up may indicate high risk.

High risk. Men who have had heart attacks within 2 weeks head the group at high risk, which also includes those with severe or unstable angina, men with uncontrolled hypertension, and patients with severe congestive heart failure, dangerous arrhythmias, moderate to severe heart valve disease, and heart muscle disease.

The conference suggests that men at high risk refrain from sexual activity, at least until their medical condition has improved substantially. Even then, full cardiovascular evaluation and individual advice are necessary before they get the go-ahead.

How About Viagra?

Until recently, human biology has provided unwanted protection for men with heart disease. That's because many of the causes of heart disease, such as smoking, diabetes, high blood pressure, and abnormal cholesterol levels, also cause impotence. The common link is atherosclerosis, which can damage arteries in the penis as well as in the heart.

Sildenafil (Viagra) has changed everything. About 70% of men with erectile dysfunction respond to the drug well enough to enable sexual intercourse. Sex may be safe for most men with heart disease, but is sildenafil a safe way to have sex?

For men with low to moderate risk, the answer is yes ≈ with one critical qualification (see Harvard Men's Health Watch, January 2000). Men who are taking nitrate medications in any form cannot use sildenafil. Moreover, men who develop symptoms of angina when they have sex after taking Viagra cannot take nitrates; they should contact a doctor and discuss the situation. This restriction covers all preparations of nitroglycerin, including long-acting nitrates, nitroglycerin patches and pastes, and amyl nitrate. Fortunately, other treatments for erectile dysfunction, such as the vacuum pump and alprostadil injections or urethral tablets, are safe for men with heart disease, even if they are using nitrates (see HMHW, September 1997).

Safe Sex

Sex is a normal part of human life. For all men, with or without heart disease, the best way to keep sex safe is to stay healthy by avoiding tobacco, exercising regularly, and eating properly. Other measures that reduce the risk of heart attack are also important; low-dose aspirin heads the list (see HMHW, January 1999). Needless to say, men should not initiate sexual activity if they are not feeling well, and men who experience possible cardiac symptoms during sex should interrupt the sexual activity at once.

With the new guidelines and simple precautions, sex is safe for the heart ≈ but it should be safe for the rest of the body, too. Sexually transmitted diseases pose a greater threat than sexually induced heart problems. When it comes to sex, men should use their heads as well as their hearts.