Never mind the side-effects of Plavix, (generic name clopidogrel), the popular anti-blood-clotting drug.
A new study reveals doubling the current recommended dose of Plavix to angioplasty patients, from 300 milligrams to 600, cut the combined risk of heart attack and cardiac death by half.
Dr. Anthony Abbate, an assistant professor of medicine at Virginia Commonwealth University says the higher dose did not increase the risk of serious bleeding, a major concern with Plavix.
Abbate and Dr. Giuseppe G. Biondi-Zoccai, an assistant professor of cardiology at the University of Turin in Italy had analyzed ten previous studies and covered 1,500 patients who had angioplasty. Most had either 300 milligrams or 600 milligrams of Plavix before the procedure.
"The evidence is very powerful," said Dr. Gregory Dehmer, president of the society and a professor of medicine at Texas A&M College of Medicine. "Although Plavix is powerful stuff, the meta-analysis did not find an excessive amount of bleeding. So we have a lower risk of myocardial infarction [heart attack] with no significant increase in adverse side effects."
The incidence of cardiac death or non-fatal heart attack was 50 percent lower in the following 30 days in those getting the higher dose of Plavix. Only 3.1 percent of those getting the 600-milligram dose had in-hospital heart attacks, compared to 6.4 percent of those getting the 300-milligram dose. The overall 30-day incidence of death or heart attack was 3.8 percent for the higher dose and 7.3 percent for the lower dose, according to the study.
"This research has important clinical and cost implications," Biondi-Zoccai said in a prepared statement.
Current guidelines by the American Heart Association, the American College of Cardiology and the Society for Cardiovascular Angiography and Interventions say that physicians should "strongly consider" giving 300 milligrams of Plavix before angioplasty, a medical procedure to open narrowed or blocked blood vessels of the heart.
"Those guidelines are in the process of having an update," Dehmer said, adding that new guidelines are expected "in the next few months."
"In practical terms, many practitioners are concerned about the current recommendations," Dehmer said. "One concern is that should the patient require elective bypass surgery, does a higher dose of clopidogrel increase the risk of excessive bleeding?
"Also there is the bleeding risk. It is addressed in this meta-analysis, which shows very minimal potential downside," he added.
But the final word is not in yet, said Dr. Marc S. Sabatine, associate professor in the cardiovascular division of Brigham and Women's Hospital in Boston. That will come from a major international study, to include up to 14,000 angioplasty patients, which is still enrolling participants, he said.
The smaller studies included in the current meta-analysis aren't definitive, Sabatine said, because there can be "publication bias," meaning that studies showing a positive result are more likely to get into print.
Timing also plays a role in treatment, he noted. Plavix must be activated in the liver, which takes about six hours, so giving it earlier makes it more effective.
But even with those side considerations, "many laboratories are considering switching to 600 milligrams," Sabatine said.