Risk high just after heart attack

People are most at risk of dropping dead in the first month after a heart attack, a new study finds, but the most effective treatment to prevent this isn’t done that early on because it, too, is considered riskiest then.

The rate of sudden death was 10 times higher in the first month after a heart attack compared to two years later, researchers report in today’s New England Journal of Medicine.

Most heart attacks are caused by blockages that deprive the pumping muscle of blood and oxygen. Treatments can clear these and restore blood flow, but damage from the heart attack can lead to abnormal rhythms that can stop the heart without warning.

The problem is becoming more common as heart attack treatment improves. Sudden death accounts for two out of three heart deaths in the United States, about 450,000 cases each year.

Studies have shown that implanted defibrillators – like the one Vice President Dick Cheney has – can help prevent sudden death by shocking the heart back into a normal rhythm. But those studies were done in patients several years after a heart attack.

Last year, a study in the same journal reported that putting the pager-size devices in people just weeks after a heart attack does not improve survival, and guidelines by the American College of Cardiology and American Heart Association recommend that doctors wait one to three months before implanting the device.

The new study shows the dilemma that creates.

Researchers studied 14,609 post-heart attack patients enrolled in a drug trial who suffered a muscle-damaging heart attack or heart failure between 1998 and 2001. Seven percent either died suddenly or were revived after cardiac arrest.

Researchers found 19 percent of all sudden deaths or cardiac arrests happened within a month of a heart attack. The rate of sudden death or cardiac arrest was highest in the first month after a heart attack – 1.4 percent compared to 0.14 after two years.

The study was funded by Novartis Pharmaceuticals, which makes several cholesterol and blood pressure-lowering drugs.