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April 25, 2022 – Researchers at the National Cerebral and Cardiovascular Center in Japan found that patients aged ≥75 years with non-valvular atrial fibrillation (NVAF) and previous stroke/transient ischemic attack (TIA) more commonly had subsequent ischemic and hemorrhagic events than those without previous stroke/TIA in the prospective, multicenter, observational All Nippon AF In the Elderly (ANAFIE) Registry.
AF is an independent risk factor for stroke, systemic embolism (SE) and all-cause death. Prior stroke/TIA increases the stroke risk of AF patients by 2.5 times. Thus, preventing subsequent ischemic stroke (IS) and intracranial hemorrhage (ICH) in AF patients with a history of stroke/TIA has become increasingly important. The challenge in anticoagulant therapy in secondary prevention is the balance between the benefit of preventing ischemic events and the risk of bleeding, in particular ICH. Both the risks of IS and ICH increase with increasing age. However, studies on the incidence of events and event risk factors in elderly patients with NVAF and previous stroke/TIA are limited.
Takeshi Yoshimoto and colleagues used a huge database of the ANAFIE Registry, where over 33,000 NVAF patients aged ≥75 years were registered from 1,273 medical institutions throughout Japan between 2016 and 2018 and followed up for 2 years.
All of stroke/SE (3.01 vs. 1.23/100 PY; adjusted hazard ratio [HR] 2.25, 95% CI 1.97–2.58), major bleeding, IS, ICH, and all-cause death were more common during follow-up in patients with stroke/TIA than those without. Thus, net clinical outcomes were also higher in stroke/TIA survivors (7.84 vs. 4.85/100 PY; adjusted HR 1.35, 95% CI 1.25–1.45). Of the 6,446 patients with previous IS/TIA, 4,393 (68.2%) were taking DOACs, and 1,668 (25.9%) were taking warfarin at enrollment. The risk of major bleeding (adjusted HR 0.67, 95% CI 0.48–0.94), ICH (HR 0.57, 95% CI 0.39–0.85), cardiovascular death (HR 0.71, 95% CI 0.51–0.99), and net clinical outcomes (HR 0.85, 95% CI 0.74–0.99) were lower in the DOAC users than in the warfarin users.
“An important finding was the low incidence of bleeding complications among patients with a history of stroke (0.97/100 PY for major bleeding; 0.67/100 PY for ICH), despite a very high prevalence of OAC use and relatively high prevalence of combined antiplatelet use (26.7%) in such aged population.” states Kazunori Toyoda, corresponding author of the paper.
The research has been published in Stroke, the official journal of the American Heart Association, as “Impact of a previous stroke on clinical outcomes in elderly patients with non-valvular atrial fibrillation: ANAFIE Registry” (DOI:10.1161/STROKEAHA.121.038285).