Abstract WP340: Loading Doses of Clopidogrel Across the US: Temporal and Regional Trends

Abstract

Introduction: Multiple trials have investigated the use of antiplatelet agents such as clopidogrel in the management of acute ischemic stroke (IS), and ongoing trials such as POINT include a loading dose followed by maintenance dosing of clopidogrel. The use of loading doses of clopidogrel is well-established in the treatment of acute coronary syndrome, but national trends in the use of clopidogrel loading doses in IS have not been well explored. Methods: In a retrospective analysis of the Premier database (a representative sample of 15% of US hospital discharges with procedure codes and medications) we identified adult patients admitted to a hospital with IS (ICD-9 codes 433.X1 and 434.X1) for years 2006-2010 and 2014. We identified those having a loading dose of Clopidogrel; defined as a total of 300mg or more on the day of or the day following admission for the acute event. We used logistic regression to examine the use of clopidogrel and loading doses over time and by region. Results: Of 341,208 IS cases (mean age 71 (14) years, 47% male, 16% black/3% Hispanic/65% white/16% other) during the study periods, 31 % received clopidogrel during hospital admission, with 0.3 % receiving a loading dose during the first 24 hours after admission. Use of clopidogrel fluctuated over the study periods but did not show a statistically significant change from 2006 to 2014; p=0.99. From 2006 to 2014, there was a 0.52 % increase in the proportion of patients receiving loading doses of clopidogrel for acute IS; rising from 0 in 2006 and 2007 to 0.52% in 2014; p<0.0001. Use of clopidogrel loading was also affected by geographic location, with 0.17, 0.28, 0.35, and 0.40 % respectively in the Northeast, South, Midwest, and West (Northeast < South, Midwest and West; South < West; all p<0.0001). Conclusion: We report temporal trends in the use of clopidogrel for the years 2006 to 2010 and 2014. Use of clopidogrel has fluctuated over this time period, while use of loading doses increased significantly over time, especially in the Western US. Understanding changes in clopidogrel use in IS on a national level is important in planning initiatives to address regional differences in access to care, as well as in the creation of standardized, evidence-based guidelines affecting clinical practice.