Antiplatelet therapy with blood thinners reduces mortality for angioplasty patients
Patients with acute coronary syndrome who have undergone angioplasty have a reduced risk of all-cause in-hospital mortality but an increased risk of bleeding when given glycoprotein 2b/3a inhibitors (GPI) after the procedure, according to a study published today in JACC: Cardiovascular Interventions.
Using data from the National Cardiovascular Data Registry CathPCI Registry, researchers assessed records from 970,865 patients with an acute coronary syndrome between July 2009 and September 2011.
Despite advances in stent design and new anticoagulants, such as bivalirudin, the study found that almost one-third of cases in the study were treated with GPI.
After adjusting for many factors, including age, gender, race, insurance status, smoking status, family history of premature coronary artery disease and prior heart attack, relative risk reductions in mortality ranged from 10 to 28 percent. The risk reduction in mortality was enhanced in patients with myocardial infarction. However, after risk adjustments, GPI use was associated with an increased risk of major bleeding.
"These findings suggest that in the modern era of angioplasty, there may still be a role for the judicious use of GPI in high-risk patients, particularly if heparin, instead of bivalirudin, is used for anticoagulation, as it was in over one-half of patients included in this study," said David M. Safley, M.D., the study's lead author and associate professor of medicine at the University of Missouri-Kansas City.
This registry-based study was able to address some of the limitations of previous randomized trials on GPI, which included mostly lower-risk patients and did not measure mortality, Safley said.
In an accompanying editorial, A. Michael Lincoff, M.D., vice-chairman of the Robert and Suzanne Tomsich Department of Cardiovascular Medicine at the Cleveland Clinic, noted the limitations due to the observational nature of the analysis. "Without randomization, any observed associations between the treatment variable (GPI) and outcome cannot be proven to be causative," Lincoff wrote.
While acknowledging the robustness of the statistical methods used, Lincoff said, "There is no advantage of GPI over bivalirudin, and the latter strategy reduces bleeding."
