A study published today in the New England Journal of Medicine led by Columbia University Medical Center and NewYork-Presbyterian Hospital researchers showed that an anti-clotting agent called bivalirudin (brand name Angiomax®), when used by itself to treat cardiac emergencies known as acute coronary syndromes (ACS), reduced the risk of major bleeding, a key risk for mortality, by 47 percent compared with the standard combination drugs. The medication was found to be equally as effective as the combination of injectable blood thinners traditionally used to maintain blood flow to the heart during these emergencies.
Results of the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial, one of the largest ACS trials to evaluate anti-clotting therapies conducted to date, demonstrated fewer cases of major bleeding in patients who were treated with bivalirudin than there were with patients treated with heparin and GPIIb/IIIa inhibitors. This resulted in a need for fewer blood transfusions. Patients who received bivalirudin alone had similar rates of ischemic complications, such as heart attack, the need for repeat procedures for artery reblockages or death as the other groups, but had significantly lower rates of major bleeding complications compared to the other groups.
As part of the trial, 13,819 study participants in 17 countries were enrolled into one of three treatment groups. One group received one of two types of the standard treatment heparin - either unfractionated heparin (UFH) or the low-molecular weight heparin enoxaparin, combined with GPIIb/IIIa inhibitors. A second group received bivalirudin and GPIIb/IIIa inhibitors. A third group received bivalirudin alone. The blood thinner has been approved to replace heparin in non-emergency angioplasty procedures, but had not been tested in more critical emergency situations, such as ACS.
"After testing several different combinations of drug therapies, we found this medication delivered by itself is as effective as combination drugs and results in less bleeding, which may lead to improved outcomes for patients who suffer from these emergent cardiac events," said Dr. Gregg Stone, M.D., the director of Research and Education for the Center for Interventional Vascular Therapy at Columbia University Medical Center and NewYork-Presbyterian Hospital, and chairman of the Cardiovascular Research Foundation, who led the study. "Use of bivalirudin alone rather than the more traditional anticoagulants in ACS patients could prevent a significant number of major bleeding episodes and blood transfusions every year in the U.S. and elsewhere."
Each year, approximately 5 million Americans are rushed to emergency rooms with severe chest pains, of which about 1.4 million are identified with ACS. ACS can be the precursor to a major heart attack or death. ACS is caused by a blockage in an artery that prevents oxygen-rich blood from reaching the heart.
When people present with ACS symptoms, they are traditionally immediately put on a cocktail of drugs that prevent the formation of blood clots that can cause a heart attack. Two of these drugs are potent anti-clotting agents: heparin, which has been in use for 100 years, and GPIIb/IIIa inhibitors. However, heparin can be problematic to use because patients have variable responses to it, and when combined with GPIIb/IIIa inhibitors heparin can thin the blood so much that it can lead to serious bleeding which prolongs the hospital stay, is costly to treat and can be fatal. Excessive bleeding is particularly a risk in patients undergoing balloon angioplasty or surgery procedures to restore blood flow to an injured heart, which are commonly performed in this setting.