Abstract 11055: Length of Anticoagulation Treatment in Provoked VTE - Lessons from the Maqi ² Collaborative

Introduction: Anticoagulation (AC) with warfarin or direct oral anticoagulants (DOAC) is the core of VTE treatment. Due to lower risk of VTE recurrence, American College of Chest Physicians (ACCP) recommends three months AC in patients with provoked VTE and without other indication for long-term AC. We aimed to assess how closely “real world” practice followed guideline recommendations. Hypothesis: We hypothesize most patients taking warfarin or DOAC for provoked VTE receive no more than three months AC. Patients who get prolonged AC are more likely to be taking DOAC than warfarin. Methods: We identified patients who initiated warfarin or DOAC from a six center AC clinic registry between 2008-20. Provoked VTE was defined as VTE after a transient risk factor: surgery, lower extremity cast/immobilization, childbirth, or OCPs. AC duration was categorized as <80, 80-120, or >120 days. Appropriate treatment window was defined as 80-120 days to adjust for variability in clinic scheduling. Median AC length for DOAC vs. warfarin was compared with a two-sample test. Prevalence of extended AC was compared using chi-square test. Variables increasing risk of extended AC were analyzed with logistic regression, adjusted for baseline demographic and clinical characteristics. Results: At six centers, we identified 488 patients with provoked VTE on warfarin and 302 on DOAC. Average AC length was 137 days for warfarin and 180 days for DOAC (p<0.0001). 266 (54.5%) patients on warfarin and 215 (71.2%) on DOAC got >120 days of AC (p<0.001). Variables increasing risk of >120 days AC include recurrent VTE (OR 2.11; CI 1.34,3.32), prior MI (OR 4.09; CI 1.37,12.2), and DOAC use (OR 2.34; CI 1.69, 3.23) (Figure 1). Conclusions: In this multi-center analysis, most patients receive AC longer than guideline-recommended. DOAC use, recurrent VTE, and prior MI are associated with prolonged AC. Understanding the relationship between prior MI and AC duration in provoked VTE warrants future investigation.