Angioplasty Trumps Clot Drugs for Heart Attack Patients
But only if additional time delay is less than an hour
FRIDAY, Oct. 3, 2003 (HealthDayNews) -- The shortest route home does you no good if traffic is heavy.
In the same vein, the best theoretical treatment for heart attacks loses its edge when you take real-world delays and deficiencies into account.
Numerous studies point to angioplasty as more effective than clot-busting drugs for people in the early throes of a heart attack. Angioplasty uses a tiny balloon to clear out blood clots that are blocking arteries.
The problem is that most U.S. hospitals don't have the capability to perform an angioplasty and the patient can lose precious time being transferred to a facility that does, researchers say.
A new comprehensive analysis of 21 existing studies, the largest ever done, analyzed the risk of death, second heart attack and stroke in the six weeks following a heart attack for patients who had received either one of these two therapies, angioplasty or clot-dissolving drugs. It then cross-referenced this data with the time it took to give the patient the initial life-saving treatment.
Although angioplasty was superior to clot-busters in saving lives among patients who received it quickly, the two strategies became equivalent when the additional delay before angioplasty treatment reached 62 minutes.
In other words, if it takes more than an hour to get patients from the entrance of the emergency room to the angioplasty suite, you might as well have been administering the drugs.
Unfortunately, a recent New England Journal of Medicine article reports that "door-to-balloon" time (the time it takes to get from the emergency room door to the angioplasty suite) is 185 minutes for patients who have to be transferred to another hospital. Only 3 percent of patients make it to the beginning of angioplasty in less than 90 minutes.
"There are so many factors that get in the way of a quick transfer that doctors have to juggle a lot of variables. I've seen it myself, hospitals within 40 miles of here not being able to get an ambulance," says Dr. Richard W. Nesto, chairman of cardiovascular medicine at the Lahey Clinic Medical Center in Burlington, Mass.
"We ask doctors, realistically speaking, how soon can you get a patient in an ambulance and, if the transfer time is going to take more than 90 minutes and may extend to two hours, we tell them to give [clot-busting drugs]," Nesto says.
Giving clot-dissolving drugs before angioplasty can reduce the effectiveness of the latter, which essentially makes this an either/or situation.
"It's really a systems issue when people don't receive their initial care at a hospital that provides primary PCI [primary percutaneous coronary intervention -- an angioplasty]. So the question becomes how can we get the patient to a primary PCI center quickly," explains Dr. Brahmajee K. Nallamothu, lead author of the analysis, which appears in the Oct. 1 issue of the American Journal of Cardiology.
Unlike Europe, the United States has no centralized system for transferring heart attack patients. Different areas of the country are, however, experimenting with models to improve care. In Seattle, for instance, an electrocardiogram -- an electrical recording of the heart -- is done in the ambulance so the decision where to send the patient can be made sooner.
"We should make this more of a nationwide system and hopefully get more of the benefits of angioplasty," says Nallamothu, an interventional cardiology fellow at the University of Michigan Medical School.
But the benefits of clot-busting drugs should not be overlooked.
"Time is still important even in this day and age," Nallamothu says. "We need to make angioplasty more available to more people but, until we're able to do that, we need to be careful about not forgetting that [drugs] are a reasonable option, especially when we anticipate substantial delays."
The National Heart Attack Alert Program is looking at ways to reduce the amount of time it takes to identify and treat a heart attack. The American Heart Association has more on identifying, treating and surviving heart attacks.