Outcomes of complex older patients with acute ischaemic stroke and atrial fibrillation: A comparison study with and without the use of oral anticoagulants for secondary stroke prevention.

Abstract

Introduction: Direct oral anticoagulants (DOACs) have become the mainstay of stroke prevention in patients with atrial fibrillation (AF). Decision to anticoagulate frail and post-stroke patients with AF may be challenging and complex. This study aimed to compare the outcomes of complex older patients with acute ischaemic stroke and AF who were treated with and without oral anticoagulants for secondary stroke prevention.

Materials and methods: This is a retrospective observational study of all older persons (≥65 years) admitted to the geriatric medicine ward in our university hospital with acute ischaemic stroke and AF from January 2016 - December 2021. The inclusion criteria in our study were patients discharged alive from hospital post-ischaemic stroke with AF. Exclusion criteria were those who died as inpatient, those undergoing end-of-life care or with very severe frailty which are contraindication to anticoagulation. Comparison was done between patients who were anticoagulated and patients who were eligible for anticoagulation but were not anticoagulated for various reasons.

Results: There were 539 patients with ischaemic stroke, of whom 110 (21%) had AF. Among them, 29 patients were excluded due to death during hospitalization (19), end-of-life (4), and very severe frailty (6). While 65 (80%, mean age 84.1 ± SD 6.3) were discharged on anticoagulation, 16 (20%, mean age 88.3 ± SD 4.3, p=0.388) were discharged without anticoagulation. The median clinical frailty score was six in both groups. Among the anticoagulated, 59 (91%) were commenced on DOACs and six (9%) were on warfarin. The main reasons recorded for not commencing anticoagulants in eligible patients were patient/family did not agree to start (8), high bleeding risk (7), and poor social support (1). Mortality was significantly higher in the non-anticoagulated group (n=10, 63%) compared to the anticoagulated group (n=22, 32%) (p=0.036).

Conclusion: Although frail older persons are perceived to have a poorer benefit/risk ratio when anticoagulated, our study demonstrated lower mortality in post-stroke anticoagulated complex older AF patients compared to those who were not anticoagulated. However, given the small numbers of participants in our study, further studies are required to determine characteristics of patients who may have better outcomes or lower risk of adverse events on anticoagulants. These findings also underscore the pressing need for a standardized, frailty-prescribing and monitoring protocol to maximise benefit and minimise risks of adverse outcomes.