Late-breaking data presented at TCT 2007, the scientific symposium of the Cardiovascular Research Foundatio, show that the use of the anticoagulant bivalirudin following angioplasty in heart attack patients reduces net adverse clinical events by 24 percent compared to the standard treatment, and significantly reduces major bleeding that occurs after angioplasty by 40 percent.
Results of the HORIZONS AMI trial, sponsored by the Cardiovascular Research Foundation, were measured at 30 days; the patients will be observed for five years to collect long-term data.
"This is a landmark trial, which will help establish the guidelines for drug and stent therapy during primary angioplasty in patients with heart attacks for many years to come," said Gregg W. Stone, MD, Chairman of the Cardiovascular Research Foundation and Professor of Medicine, Columbia University Medical Center.
"Usually, angioplasty is associated with an excess of bleeding in heart attack patients," Dr. Stone said. "In the first phase of the HORIZONS AMI trial, we sought to determine whether using bivalirudin instead of heparin and glycoprotein IIb/IIIa inhibitors in patients with a heart attack after angioplasty reduces this high rate of bleeding and improves survival, as it does in stable coronary artery disease."
In addition, while previous studies of drug-eluting stents have often focused on their use in patients with stable or unstable chest pain, this is the largest study to focus on the appropriate use of anticoagulation medications and drug-eluting stents in patients experiencing the most dangerous form of heart attack (ST-elevation myocardial infarction).
The HORIZONS AMI trial enrolled over 3600 patients presenting to hospitals in 11 countries with a heart attack. More than 120 national and international interventional cardiology centers are participating in the trial. Patients undergoing angioplasty were randomly assigned to receive either the standard anticoagulant regimen of unfractionated heparin plus a glycoprotein IIb/IIIa inhibitor or bivalirudin alone. The patients are to be followed for five years.
At 30 days, net adverse clinical events -- a combination of major bleeding or major adverse cardiac event -- were 12.1% in patients receiving heparin and GP IIb/IIIa inhibitors, and 9.2% in patients receiving bivalirudin alone. And when considered by itself, major bleeding was 8.3% in patients on combination drug therapy, vs. 4.9% in patients on bivalirudin alone.
In an important finding, cardiac deaths at 30 days were significantly higher in patients on heparin and GP IIb/IIIa inhibitors (2.9%) than those on bivalirudin alone (1.8%). Other important endpoints, such as second heart attacks and strokes, occurred with nearly identical frequency with bivalirudin and standard therapy.
"This study determines that bivalirudin use is safer than previous standard anticoagulant therapy, without causing excess bleeding in these acutely ill patients with a heart attack undergoing angioplasty, which may translate into lower mortality," said Roxana Mehran, MD, Medical Director of the Data Coordinating and Analysis Center at CRF stated. She and her team conducted this study under an Investigational Device Exemption (IDE) from the Food and Drug Administration.
Comparison of Drug-Eluting Stents to Bare-Metal Stents Underway
Patients enrolled in the HORIZONS AMI trial were also randomly assigned to receive either Taxus drug-eluting stents or a bare-metal stent. Data on this portion of the study -- also a landmark comparison of drug-eluting stents to bare-metal stents -- will be available next year.
Materials provided by Cardiovascular Research Foundation. Note: Content may be edited for style and length.
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