Aspirin and warfarin: A combination for everyone?
Huang K, Shah V, Ahsan S, Kaatz S, Krol G, Ellsworth S, Ryan N, Gentile J, and Wilkinson B. Aspirin and warfarin: A combination for everyone? J Thromb Thrombolysis 2019; 47(4):616-617.
J Thromb Thrombolysis
Introduction: The addition of aspirin (ASA) to warfarin increases the risk of serious bleeding. The purpose was to decrease unnecessary ASA use in patients on warfarin. Methods: Quality improvement initiative from single center results analyzed from Henry Ford Hospital, 1 of 6 anticoagulation clinics involved in the Michigan Anticoagulation Quality Improvement Imitative (MAQI$sup$2$/sup$). Institutional Review Board approval was obtained. Inappropriate use of aspirin was defined as any patient on warfarin and concomitant ASA without any of the following co-morbidities: coronary artery disease, peripheral artery disease, heart valve replacement, prior stroke, and left ventricular assist device (LVAD). For patients identified, an initial email was sent to the enrolling anticoagulation physician requesting a review to discontinue ASA. If no response was received within 7 days of a second email, the enrolling physician was called by one of the investigators using a standardized script. Results: Combined warfarin and aspirin use was found in 29.5% [95% CI 28.2-30.9] or 1348 of 4565 patients on warfarin in the anticoagulation clinic. Inappropriate ASA use was identified in 140 patients (10.4%; 95% CI 8.8-12.0). Of those 140 identified, 125 discontinued ASA per their provider (89.3%; 95% CI 84.2-94.4), reducing the number of patients inappropriately on ASA by 9.3% [95% CI 7.8%-10.9%]. Conclusions: Over one quarter of patients on warfarin are on ASA and approximately 10% of these patients with no clear indication. When providers are contacted with the information, the vast majority are receptive to stopping ASA which should decrease bleeding risk in this group of patients.