Known knowns and known unknowns: risks associated with combination antithrombotic therapy

摘要: Background: Use of antiplatelet therapy in combination with oral anticoagulants remains controversial. The purpose this article is to review current consensus recommendations for antithrombotic therapy, evaluate risks bleeding among patients taking and lastly single-center data from Kaiser Permanente Colorado detailing clinical outcomes associated therapy. Methods: This was a retrospective, longitudinal pharmacoepidemiologic review. Adult receiving warfarin managed by pharmacy service who had documented (aspirin, clopidogrel, and/or dipyridamole) use (combination cohort) or non-use (monotherapy were identified as September 30, 2005. Utilizing integrated, electronic medical records, anticoagulation-related adverse events (death, hemorrhage, thrombosis) coronary during six-month follow-up (October 2005 through March 2006). Proportions compared between cohorts. Independent associations the cohorts assessed adjustment potential confounding factors. Results: Data 2,560 monotherapy 1,623 analyzed. Patients cohort more likely have hemorrhages (4.2% vs. 2.0%, unadjusted p<0.001). With adjustment, combined independently hemorrhagic (OR=2.75; 95% Cl 1.44, 5.28) but not (OR=0.99; 0.37, 2.62) events. Conclusions: At population level, risk appears outweigh benefits. These findings suggest that clinicians carefully consider benefits when prescribing do meet evidence-based criteria approach.