Clot-busting drugs that save thousands of heart attack patients each year can be deadly when given to elderly patients, doctors report today.
Their study highlights what appears to be a serious problem with one of the century’s major medical advances — one that gave doctors the power to halt heart attacks in progress, says lead author Stephen Soumerai of Harvard Medical School (news – web sites).
”This was a huge innovation,” he says. ”It’s one of the most effective therapies in cardiology, and it has been hyped by everybody from the manufacturers to the National Heart, Lung, and Blood Institute.”
But he added that most of the studies that led to the drugs’ approval, as with many other studies, excluded people over 75. ”We’re living in a world without data on the benefits and risks of drugs in people over 75.”
The drugs, known as streptokinase and t-PA, dissolve artery-clogging blood clots if given within 12 hours of the start of symptoms. But they also may cause life-threatening bleeding.
Older people with fragile arteries are more prone to bleeding. About 2.7 million people 75 and older suffer from coronary artery disease, and 350,000 of them die each year, according to the American Heart Association (news – web sites).
The four-year study of 2,659 heart attack patients treated in Minnesota hospitals found:
* Patients younger than 80 were more likely to survive if they received clot-busters.
* Patients 80 to 90 who were given clot-busters had a 40% higher death rate than people in that age group who did not get the drugs.
* Roughly 38% of people given clot-busters were ineligible for them, because they had conditions that predisposed them to bleeding, raising their risk of death at any age.
Christopher Cannon, a Harvard cardiologist who did not work on the study, cautioned that such ”observational” studies ”should be taken with a grain of salt” because they’re not as reliable as randomized, placebo-controlled studies that lead to drug approval.
Jerry Gurwitz of the University of Massachusetts Medical School, a co-author, says no such study likely will be done, because doctors would have a hard time randomly putting heart attack patients on a placebo when this therapy is proven to save lives.
”In no way do I think this study supports the recommendation that elderly patients shouldn’t be treated,” he says. Rather, he says, the study in Annals of Internal Medicine ”suggests strongly that physicians have to be very careful in their decision-making, selecting only appropriate patients.”
He said doctors must consider alternatives to clot-busters, including immediate balloon angioplasty.
But only 20% of hospitals are equipped to provide it.