A major international study by cardiologists has shown that the addition of tirofiban into the medical management of patients with unstable angina reduces their risk of death by as much as 47%. Unstable angina is currently the leading cause of admissions to coronary care units, accounting for more than 1.4 million hospitalizations per year in the United States. Tirofiban, a member of a new class of anti-platelet inhibitors, proved so effective in decreasing the incidence of post-angina heart-attacks that the researchers recommended its use as part of a new therapeutic standard of care. The researchers' study and clinical recommendation will be published in the May 21 issue of The New England Journal of Medicine.
Unstable angina is a life-threatening cardiac condition that occurs when bloodflow to the heart muscle is disrupted or impaired. In most cases, the pain of angina is associated with the rupturing of large cholesterol plaques that have built-up, over time, near the outer walls of the heart chamber. "At the present time, we treat this condition with a combination of heparin and aspirin because both of those drugs have unique properties that encourage the dissolution of plaques," explains Howard Herrmann, MD, associate professor of medicine at the University of Pennsylvania Medical Center -- one of the 72 participating trial sites. "Our study showed that the intravenous introduction of tirofiban into the standard treatment protocol provides additional benefit to patients because tirofiban helps prevent the development of plaque deposits by blocking the aggregation of platelets -- which is a precursor to clot development."
In their two-year investigation of 1,915 patients with unstable angina or non-Q-wave myocardial infarction (which represents the middle ground, clinically speaking, between angina and a full-blown heart attack), the researchers tested the effectiveness of tirofiban in addition to heparin and aspirin [PRISM-PLUS]. They found that tirofiban -- in combination with heparin/aspirin --resulted in a 47% risk-reduction for heart attack within the first week of treatment, and a 30% risk-reduction at thirty days. "These numbers demonstrate very clearly the effectiveness of including tirofiban in the standard of care for treating patients with angina," notes Herrmann, who served as principal investigator for the Penn portion of the world-wide study.
On the basis of the study results, tirofiban has received approval from the Food and Drug Administration (FDA) for the treatment of unstable angina. The drug is manufactured by Merck under the trade name of aggrastat.
Editor's Notes: Dr. Herrmann may be reached for comment directly at (215) 662-2180.
Dr. Herrmann holds no stock in Merck. He has been a paid lecturer and consultant to the pharmaceutical company; and is currently conducting a Merck-sponsored clinical trial.
Journal
New England Journal of Medicine