Off-label-dosing of non-vitamin K-dependent oral antagonists in AF patients before and after stroke: results of the prospective multicenter Berlin Atrial Fibrillation Registry.

AIMS: We aimed to analyze prevalence and predictors of NOAC off-label under-dosing in AF patients before and after the index stroke. METHODS: The post hoc analysis included 1080 patients of the investigator-initiated, multicenter prospective Berlin Atrial Fibrillation Registry, designed to analyze medical stroke prevention in AF patients after acute ischemic stroke. RESULTS: At stroke onset, an off-label daily dose was prescribed in 61 (25.5%) of 239 NOAC patients with known AF and CHA2DS2-VASc score ≥ 1, of which 52 (21.8%) patients were under-dosed. Under-dosing was associated with age ≥ 80 years in patients on rivaroxaban [OR 2.90, 95% CI 1.05-7.9, P = 0.04; n = 29] or apixaban [OR 3.24, 95% CI 1.04-10.1, P = 0.04; n = 22]. At hospital discharge after the index stroke, NOAC off-label dose on admission was continued in 30 (49.2%) of 61 patients. Overall, 79 (13.7%) of 708 patients prescribed a NOAC at hospital discharge received an off-label dose, of whom 75 (10.6%) patients were under-dosed. Rivaroxaban under-dosing at discharge was associated with age ≥ 80 years [OR 3.49, 95% CI 1.24-9.84, P = 0.02; n = 19]; apixaban under-dosing with body weight ≤ 60 kg [OR 0.06, 95% CI 0.01-0.47, P < 0.01; n = 56], CHA2DS2-VASc score [OR per point 1.47, 95% CI 1.08-2.00, P = 0.01], and HAS-BLED score [OR per point 1.91, 95% CI 1.28-2.84, P < 0.01]. CONCLUSION: At stroke onset, off-label dosing was present in one out of four, and under-dosing in one out of five NOAC patients. Under-dosing of rivaroxaban or apixaban was related to old age. In-hospital treatment after stroke reduced off-label NOAC dosing, but one out of ten NOAC patients was under-dosed at discharge. CLINICAL TRIAL REGISTRATION: NCT02306824.

Oral anticoagulation in patients with atrial fibrillation and acute ischaemic stroke: design and baseline data of the prospective multicentre Berlin Atrial Fibrillation Registry.

AIMS: The Berlin Atrial Fibrillation Registry was designed to analyse oral anticoagulation (OAC) prescription in patients with atrial fibrillation (AF) and acute ischaemic stroke. METHODS AND RESULTS: This investigator-initiated prospective multicentre registry enrolled patients at all 16 stroke units located in Berlin, Germany. The ongoing telephone follow-up is conducted centrally and will cover 5 years per patient. Within 2014 and 2016, 1080 patients gave written informed consent and 1048 patients were available for analysis. Median age was 77 years [interquartile range (IQR) 72-83], 503 (48%) patients were female, and 254 (24%) had a transient ischaemic attack (TIA). Overall, 470 (62%) out of 757 patients with known AF and a (pre-stroke) CHA2DS2-VASc ≥ 1 were anticoagulated at the time of stroke. At hospital discharge, 847 (81.3%) of 1042 patients were anticoagulated. Thereof 710 (68.1%) received a non-vitamin K-dependent oral anticoagulant (NOAC) and 137 (13.1%) a vitamin K antagonist (VKA). Pre-stroke intake of a NOAC [odds ratio (OR) 15.6 (95% confidence interval, 95% CI 1.97-122)] or VKA [OR 0.04 (95% CI 0.02-0.09)], an index TIA [OR 0.56 (95% CI 0.34-0.94)] rather than stroke, heart failure [OR 0.49 (95% CI 0.26-0.93)], and endovascular thrombectomy at hospital admission [OR 12.9 (95% CI 1.59-104)] were associated with NOAC prescription at discharge. Patients' age or AF type had no impact on OAC or NOAC use, respectively. CONCLUSION: About 60% of all registry patients with known AF received OAC at the time of stroke or TIA. At hospital discharge, more than 80% of AF patients were anticoagulated and about 80% of those were prescribed a NOAC.