The impact of ischemic stroke and intracerebral hemorrhage with non-Vitamin K antagonist oral anticoagulants in patients with paroxysmal and persistent atrial fibrillation: A population based cohort study

Current guidelines recommend oral anticoagulants (OACs) for CHA2DS2-VASc scores of 2, regardless of the subtype of paroxysmal atrial fibrillation (PRX AF) or persistent AF (PRS AF). However, the likelihood of ischemic stroke events occurring in PRX AF may be lower than that in PRS AF. Nevertheless, the bleeding risk associated with the use of OACs in these two groups has not yet been fully explored. This study aimed to assess the effect of nonvitamin K antagonist OAC (NOAC) therapy on ischemic stroke events and intracerebral hemorrhage (ICH) risk. This was a retrospective population-based cohort study using Taiwan's National Health Insurance Research Database from 2014 to 2019. The cohort comprised patients who were newly diagnosed with AF. To minimize potential confounding, inverse probability treatment weighting (IPTW) was applied to balance baseline characteristics between NOAC and non-NOAC groups. The endpoint encompassed the incidence of ischemic stroke and intracranial hemorrhage (ICH). Compared with the patients in the non-NOAC group, those with PRX AF receiving NOACs demonstrated a significant reduction in the risk of ischemic stroke [hazard ratio (HR), 0.86; 95 % confidence interval (CI), 0.78–0.94], whereas no significant difference in the risk of intracerebral hemorrhage was found (HR, 1.0; 95 % CI, 0.87–1.16). In the PRS AF cohort, NOACs significantly lowered the risk of both ischemic stroke (HR, 0.85; 95 % CI, 0.77–0.93) and ICH (HR, 0.86; 95 % CI, 0.74–0.99). We concluded that among patients with PRX AF and PRS AF, those treated with NOACs exhibited a significant reduction in ischemic stroke risk. However, only in PRS AF, the NOAC group demonstrated a significant reduction in ICH risk compared with the nonNOAC group.