The answer is "yes," but it's a qualified yes. In the two-hour period after sex, the risk of having a heart attack goes up 2.5-fold. That sounds like a lot, but if you double the risk of a rare event it's still going to be a rare event. (What if I told you that by walking past a music store you triple your risk of having a piano fall on your head—from one in 1 billion to three in 1 billion?) It turns out that having sex once a week for a year increases the risk of having a heart attack in that same time frame by 0.01 percent (one in 10,000) in healthy individuals, and by 0.1 percent (one in 1,000) for those with cardiovascular disease. (The absolute risks are very low.)
Doctors understand some of the risk factors for coronary artery disease (smoking, diabetes, etc.), but we don't have a clear idea of what acts as the final trigger for a heart attack. Certain behaviors do seem more likely than others to set off an unfortunate episode: Waking up in the morning, physical exertion, sexual activity, and anger. Yet all of these taken together can only account for a minority of cases. Physical (but nonsexual) overexertion is thought to cause about 5 percent of all heart attacks, anger 3 percent, and sex less than 1 percent. It's worth noting that sex and anger both involve extremes of emotional arousal, and they both increase heart attack risk to the same degree—about 2.5-fold. As DeBusk points out, the reason anger ends up causing a greater percentage of all heart attacks is that people tend to have more angry outbursts than sex.
All of this leaves me to wonder why the "Ask your doctor …" caution appears so consistently in erectile dysfunction drug ads. Is it a friendly public-service announcement? Legal cover-your-gluteus maneuvering? A marketing ploy to add a titillating sense of danger? What's odd is that drug-ad warnings typically address the side effects of the drug—"In the rare event of an erection lasting more than 4 hours, seek immediate medical help to avoid long-term injury." It's unusual for a warning to be focused solely on the consumer. Ads for osteoporotic drugs don't say, "Ask your doctor if you're healthy enough to climb up a ladder, from which you could fall and easily break something." Ads for Alzheimer's drugs don't say, "Ask your doctor if you're healthy enough to drive in heavy traffic, operate complicated machinery, or be the 40th president of the United States and leader of the Free World."
The difference lies in the fact that most drugs work by preventing something—thinning bones, for example, or fading memories. But ED drugs are proactive in the literal sense of the word, allowing men to once again participate in an activity that carries some small but tangible increase in cardiovascular risk. The Food and Drug Administration's Division of Drug Marketing, Advertising and Communications stipulates that broadcast ads must include the drug's most important risks, and having a heart attack whilst flying your broomstick over the Emerald City qualifies as such. Particularly if you've been flying around up there for more than four hours.
The lesson here is that having sex increases one's risk of having a heart attack, but only to a very small degree, and let's be honest: Everything increases one's risk for something. Swimming, for instance, increases the risk of drowning. Standing increases the risk of falling. My advice is, don't mix physical exertion, anger, and sex. If you can't agree on whose turn it is to drag the claw-foot bathtubs to the edge of the surf, hire a mover. Really, it's not worth getting worked up about.