Study Examines Outcomes in Geriatric MI Patients Administered Triple Antiplatelet Therapy

Research conducted at the Duke University School of Medicine indicates triple therapy may increase risk of bleeding in geriatric patients with myocardial infarction who have a stent.

Is more better or worse was the question asked by researchers in a study evaluating 2 versus 3 antithrombotic agents in older patients (≥65 years) with acute myocardial infarction (MI) with atrial fibrillation (AF) who were treated with percutaneous coronary intervention (PCI).

The retrospective study examined data of nearly 5000 patients from the National Cardiovascular Data Registry ACTION Registry, between January 2007 and December 2010, who had a history of AF, were treated with angioplasty, and had also received a coronary stent. The primary outcomes examined were 2-year major adverse cardiac events (MACE) comprising death, readmission for MI, or stroke. To compare response to antiplatelet treatment, outcomes with dual antiplatelet therapy (DAPT) were compared with triple therapy (DAPT plus warfarin) using the Cox proportional hazard model.

A little over 27% of the study population was discharged on triple therapy, the authors found, and while they had a similar risk of MACE as those on DAPT, they had a significantly greater risk of bleeding that needed hospitalization as well as a greater risk of intracranial hemorrhage. A majority of these patients on triple therapy were frequently on warfarin prior to being admitted to the hospital.

The authors conclude that triple therapy increased the patient’s risk for major bleeding but did not significantly influence MI, death, or stroke.

"The increased risk of bleeding without apparent benefit of triple therapy observed in this study suggests that clinicians should carefully consider the risk-to-benefit ratio of triple therapy use in older atrial fibrillation patients who have had a heart attack treated with angioplasty," said Connie N. Hess, MD, MHS, from the Duke University School of Medicine and senior study author. Further prospective studies of different combinations of anti-clotting agents are needed to define the optimal treatment regimen for this population."