Anticoagulation Changes Following Major and Clinically Relevant Nonmajor Bleeding Events in Non-valvular Atrial Fibrillation Patients

Abstract

Background Bleeding events are common complications of oral anticoagulant drugs, including both warfarin and the direct oral anticoagulants (DOACs). Some patients have their anticoagulant changed or discontinued after experiencing a bleeding event, while others continue the same treatment. Differences in anticoagulation management between warfarin- and DOAC-treated patients following a bleeding event are unknown. Methods Patients with non-valvular atrial fibrillation from six anticoagulation clinics taking warfarin or DOAC therapy who experienced an International Society of Thrombosis and Haemostasis (ISTH)-defined major or clinically relevant non-major (CRNM) bleeding event were identified between 2016 and 2020. The primary outcome was management of the anticoagulant following bleeding (discontinuation, change in drug class, and restarting of same drug class). DOAC- and warfarin-treated patients were propensity matched based on the individual elements of the CHA2DS2-VASc and HAS-BLED scores as well as the severity of the bleeding event. Results Of the 509 patients on warfarin therapy and 246 on DOAC therapy who experienced a major or CRNM bleeding event, the majority of patients continued anticoagulation therapy. The majority of warfarin (231, 62.6%) and DOAC patients (201, 81.7%) restarted their previous anticoagulation. Conclusion Following a bleeding event, most patients restarted anticoagulation therapy, most often with the same type of anticoagulant that they previously had been taking.

Comparison of Patient Outcomes Before and After Switching From Warfarin to a Direct Oral Anticoagulant Based on Time in Therapeutic Range Guideline Recommendations

“…The outcomes assessed were ischemic stroke and major bleeding based on International Society of Thrombosis and Hemostasis criteria. 5 This report follows the STROBE reporting guideline. This study received a waiver of participant consent from the institutional review board because of minimal risk to participants.…”

“…Rates of major bleeding were adjusted by a modified HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR [international normalized ratio], elderly, drugs/alcohol concomitantly) score (as continuous variable-removing the labile INR) while rates of ischemic stroke were adjusted by CHA 2 DS 2 -VASc score (as continuous variable) and compared using a mixed model with patients as random effect. 5 Categorical variables were assessed using χ 2 test or Fisher exact test. Two-sided P < .05 was considered significant for all comparisons.…”

“…Patients were excluded if NVAF was not the only indication for anticoagulation or if they did not have at least 6 months of follow-up after switching to a DOAC. The outcomes assessed were ischemic stroke and major bleeding based on International Society of Thrombosis and Hemostasis criteria . This report follows the STROBE reporting guideline.…”

“…Each group’s outcome rates (number per 100 patient-years) while taking warfarin were compared with rates after switching to a DOAC. Rates of major bleeding were adjusted by a modified HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR [international normalized ratio], elderly, drugs/alcohol concomitantly) score (as continuous variable-removing the labile INR) while rates of ischemic stroke were adjusted by CHA 2 DS 2 -VASc score (as continuous variable) and compared using a mixed model with patients as random effect …”