Abstract 3066: Implementation of Results from Major Clinical Trials on Utilization Patterns of Antithrombotic Agents following Noncardioembolic Ischemic Stroke or TIA in the United States (2000-2009)
Background and Purpose: Several large trials published over the last decade have significantly altered recommended guidelines for therapy following a noncardioembolic ischemic stroke or transient ischemic attack (TIA). We examined utilization patterns of these agents over the last decade, with regards to the publication of the MATCH, ESPRIT, and PRoFESS clinical trials, to study the implementation of the results of such trials in clinical practice.
Methods: Antithrombotic utilization was prospectively collected as part of the National Ambulatory Medical Care Survey (NAMCS) between 2000 and 2009. Patients with a history of ischemic stroke or TIA were included with the exception of those with a concomitant history of atrial fibrillation, atrial flutter, or heart valve replacement. Annual utilization prevalence of the following antithrombotic strategies was compared: aspirin monotherapy, clopidogrel monotherapy, combined clopidogrel and aspirin, dipyridamole-aspirin, and warfarin. Average annual prevalence was compared before and after publication of MATCH in 2004, ESPRIT in 2006, and PRoFESS in 2008. A second pre-specified analysis excluded patients with known coronary artery disease (CAD) to censor the use of combined clopidogrel and aspirin for treatment of CAD after the 2001 CURE and 2002 CREDO trials showed a benefit of extended dual antiplatelet therapy.
Results: An annual average of 4,221,059 patients between 2000 and 2009 met criteria for evaluation. After the 2004 MATCH trial, the annualized rate of combined clopidogrel and aspirin use increased from 3.3% before trial publication to 6.8% afterwards (p<0.0001). When patients with CAD were excluded an increase of 3.3% to 5.5% was found during the same period (p<0.0001). Following the 2006 ESPRIT trial, the annualized rate of dipyridamole-aspirin use increased from 2.8% to 4.6% (p<0.0001); the annualized rate of clopidogrel use increased from 12.8% to 17.8% (p<0.0001); and the annualized rate of aspirin use increased from 12.6% to 16% (p<0.0001). After the PRoFESS trial, published in late 2008, the annualized rate of clopidogrel use increased from 13.8% to 19% (p<0.0001); the annualized rate of dipyridamole-aspirin use minimally increased from 3.3% to 4% (p<0.0001); and the annualized rate of aspirin use decreased from 14.2% to 11% (p<0.0001).
Conclusion: The impact of the MATCH, ESPRIT, and PRoFESS trials on antithrombotic utilization has been variable. The results highlight the importance of addressing factors that facilitate or hinder the implementation of results from such trials into practice.
- © 2012 by American Heart Association, Inc.