Super Aspirins for Heart Attack Patients Getting Mixed Reviews
March 15, 2000 (Anaheim, Calif.) -- For years, heart specialists have known that giving heart attack patients an aspirin a day improves the patient's chance of survival because the aspirin blocks the formation of new blood clots. So, when new drugs were developed that had even more powerful clot-prevention properties, it seemed a good guess that these "super aspirins" would work even better than plain, old, ordinary aspirin. A good theory, perhaps, but in practice, the oral super aspirins are dismal -- and possibly dangerous -- failures.
The new agents -- called glycoprotein IIb/IIIa inhibitors -- are available both as IV drugs and in pill form. One of the more exasperating aspects of this latest research is the fact that the IV formulations work extremely well. In a new trial, giving one of these IV drugs to patients who underwent angioplasty and stent procedures to open blocked arteries cut the risk of death or major complications by 40%. But when the drugs are given in pill form, they fail miserably.
Researchers studying these new drugs discussed the latest findings here Tuesday in a press conference at a meeting of the American College of Cardiology.
Last month, scientists stopped the clinical trial of the IV super aspirin Integrilin (eptifibatide) because results at that time were so positive that they decided it was unethical to give placebo to some patients.
Lead researcher James Tcheng, MD, tells WebMD that he hopes this trial will change the way heart attack patients are treated. "[Currently,] about 70% of patients [eligible to receive the therapy] are not getting [it]," he says. The new study showed that the drug reduced mortality and major heart attacks by 40% compared to placebo. He adds that Integrilin may offer a good -- but far less costly -- alternative to a similar drug called Reopro (abciximab). "Reopro costs about $1,500, whereas Integrilin costs about $400."
While the news from that study was undeniably positive, it was overshadowed by the latest grim results on the oral super aspirins. This bad news came from a study called 2nd SYMPHONY, in which more than 6,500 heart attack patients were given the experimental drug called sibrafiban (in either low or high dose) along with aspirin or aspirin alone.
Robert M. Califf, MD, professor of medicine and director of the Duke Clinical Research Institute in Durham, N.C., says that these latest results were very much a replay of earlier clinical trials, which demonstrated again and again that oral super aspirin is no match for regular aspirin. Overall, patients taking sibrafiban at any dose were more likely to have an adverse event and were more likely to have a major bleeding event, he says.
The most damaging finding in the trials of oral super aspirin concerned mortality. In both trials, very few patients died, but in each study, more deaths occurred among patients treated with the super aspirin than with plain aspirin.