Trends in usage of alternative antiplatelet therapy after stroke and transient ischemic attack

The effects of alternative antiplatelet agents such as clopidogrel and dipyridamole have been studied in clinical trials and heavily marketed. Because public data on their usage are limited, we examined trends in their prescription after stroke and transient ischemic attack to assess the impact of marketing and trial results.

Between 2001 and 2005, 85 US hospitals prospectively enrolled all patients admitted with ischemic stroke or transient ischemic attack into a registry designed for quality improvement (Ethos). Data on rates of antiplatelet medication usage at discharge were examined over time, and trends were evaluated by the Mantel-Haenszel test.

Among 18 020 patients included during the 4-year period, 89% were discharged on antithrombotic medication. Between the first quarter of 2001 and the first quarter of 2004, prescription of clopidogrel-aspirin doubled (P<0.0001 for trend), coincident with publication of results from CURE and CREDO showing efficacy in patients with acute coronary syndromes. Monotherapy with aspirin or clopidogrel decreased concomitantly, and use of dipyridamole-aspirin remained constant. After an increased bleeding risk was reported in the clopidogrel-aspirin arm of the MATCH trial, use of the combination decreased sharply from 31.5% in the first quarter of 2004 to 12.8% in the first quarter of 2005 (P<0.0001), while an increase was seen in the use of clopidogrel alone (7.6% to 12.8%, P=0.03) and dipyridamole-aspirin (7.4% to 20.2%, P<0.0001).

Clopidogrel and dipyridamole-aspirin are used frequently after stroke or transient ischemic attack. Use of clopidogrel-aspirin was common in patients with recent ischemic stroke before the publication of MATCH, after which rates dramatically declined and use of dipyridamole-aspirin and clopidogrel alone increased.