Resumption of anticoagulation therapy among Non-Valvular Atrial Fibrillation (NVAF) patients with prior intracranial haemorrhage

Abstract Purpose Resumption of anticoagulation therapy (OAC) in patients with non-valvular atrial fibrillation (NVAF) suffering from intracranial haemorrhage (ICH) is challenging in clinical practice. The aim of this study was to evaluate impact of resumption of OAC on clinical outcomes in NVAF patients with history of ICH. Methods Consecutive patients with NVAF with or without OAC who survived from an index ICH between January 2018 and July 2022 in 16 public hospitals in Hong Kong were identified and analyzed retrospectively. Resumption of OAC was substantiated by new prescription obtained from electronic medical records. Patients were divided into 5 groups: (i) OAC naïve (as reference group); (ii) resume direct oral anticoagulant (DOAC); (iii) resume Vitamin K antagonist (VKA); (iv) discontinue DOAC; (v) discontinue VKA. Risks of ischemic stroke, recurrent ICH and all-cause mortality were estimated for all groups and compared with individuals without OAC, using adjusted sub-distribution hazard ratios (aSHR) derived from Fine and Gray regression models, accounting for death as competing risk, adjusting for components of CHA2DS2VASC and HASBLED scores. Sub-analysis was conducted to compare outcomes between different DOAC agents (i.e, apixaban, dabigatran, edoxaban, rivaroxaban), using VKA as reference among patients who resumed DOAC or VKA. Results Of 982 patients who met inclusion criteria (mean age 77.7±10.9, female 40.9%), 39.1% (n=384) were OAC naive, 32.2% (n=316) resumed DOAC, 12.6% (n=124) resumed VKA, 9.0% (n=88) discontinued DOAC and 7.1% (n=70) discontinued VKA. During a median follow-up period of 2.0 (IQR: 0.7-3.5) years, no statistically significant difference in risk of ischemic stroke was observed among 5 groups. Discontinuation of DOAC was associated with markedly higher risk of ischemic stroke (aSHR=8.32 (1.8-39.3)) only among AF patients with CHA2DS2VASC score ≥ 4, Risk of recurrent ICH was higher in patients who resumed VKA (aSHR=1.6(1.0-2.5)). Sub-analysis demonstrated resumption of apixaban was associated with lowest risk of recurrent ICH (aSHR=0.6(0.4-0.9)). Compared to OAC naïve patients, those who resumed DOAC (aSHR=0.5(0.4-0.7)) had lowest risk of all-cause mortality, whereas discontinuation DOAC (aSHR=1.9(0.4-2.5) and VKA (aSHR=1.6(0.2-2.2)) were both associated with increased mortality. Conclusion Our real-world data revealed among NVAF patients with prior ICH long term discontinuation of OAC was associated with increased risk of ischemic stroke. Recurrent ICH was highest among patients who resumed VKA and lowest with apixaban.