Incidence of bleeding in patients with atrial fibrillation and advanced liver fibrosis on treatment with vitamin K or non-vitamin K antagonist oral anticoagulants

Objectives: To investigate the incidence of bleeding events in atrial fibrillation (AF) patients treated with vitamin K (VKAs) or non-vitamin K antagonist oral anticoagulants (NOACs) screened for the presence of liver fibrosis (LF). Background: Previous studies provided conflicting results on bleeding risk in AF patients with liver disease on VKAs, and no data on NOACs in this setting are available. Methods: Post-hoc analysis of a prospective, observational multicentre study including 2330 AF outpatients treated with VKAs (n = 1297) or NOACs (n = 1033). Liver damage was quantified by the FIB-4 score (>3.25), a validated marker of LF. The primary endpoint was the incidence of any bleeding, according to ISTH classification. Results: A high FIB-4 was present in 129 (5.5%) patients: 77 (5.9%) on VKA and 52 (5.0%) on NOACs (p = 0.344). During follow-up, 357 (15.3%) patients experienced a bleeding: 261 (80 major and 180 minor) with VKAs (7.2%/year), and 96 (40 major and 56 minor) with NOACs (6.4%/year). In VKA-treated patients, but not in those on NOACs, FIB-4 >3.25 was associated with higher major bleeding (14.3% vs. 5.6%, log-rank test p < 0.001). Multivariable Cox regression model showed that FIB-4 was associated with major bleeding only in VKA-treated patients (HR: 3.075, 95% CI 1.626–5.818, p = 0.001). On multivariable analysis, FIB-4 was not significantly associated with CVEs neither in VKA or NOAC-treated patients. Conclusion: We found a significant association between LF and major bleedings in AF patients treated with VKA, which was not evident in patients on NOACs.