Early anticoagulation in atrial fibrillation-related acute ischaemic stroke: efficacy and safety profile

Abstract

Objectives: To evaluate the effects of early anticoagulation on functional outcome, recurrent ischaemic events and haemorrhagic complications in Atrial Fibrillation (AF)-related acute ischaemic strokes (AIS).

Materials and methods: We retrospectively evaluated patients hospitalised in a Stroke Unit due to AF-related AIS. Patients were divided according to anticoagulation initiation timing (0-4 days, 5-14 days, no anticoagulation by the 14th day). We assessed the following outcomes at 3 months: favourable functional outcome [modified Rankin Scale (mRS) score 0-2 or equal to pre-stroke], recurrent ischaemic events and haemorrhagic complications after anticoagulation initiation.

Results: We included 395 patients. Anticoagulation was initiated at days 0-4 in 33.9% of patients, days 5-14 in 25.3% and not initiated by the day 14 in 40.8%. Factors associated with earlier anticoagulation included lower previous mRS, valvular AF and lower stroke severity. Favourable functional outcome occurred in 40.2% of patients, with lower odds in those anticoagulated at 5-14 versus 0-4 days (OR: 0.47, 95% CI: 0.23-0.94), independently of age, previous mRS and stroke severity. Recurrent ischaemic events occurred in 8.3% of patients, with higher odds in non-anticoagulated patients by the 14th day, compared to the remainder groups (OR: 3.26, 95% CI: 1.29-8.22 vs. 0-4 days and OR: 8.16, 95% CI: 1.76-37.9 vs. 5-14 days). In patients who started anticoagulation (n = 288), haemorrhagic complications occurred in 10.8%, being more frequent in those who started at 0-4 days vs. > 14 days. However, it did not abolish the 0-4-day initiation's benefit on functional outcome.

Conclusions: Early anticoagulation was associated with lower ischaemic recurrence and better functional outcome at 3 months. Additional studies are needed to better clarify its haemorrhagic risk.

Keywords: Acute ischaemic stroke; Atrial fibrillation; Early anticoagulation; Functional outcome; Haemorrhagic complications; Secondary prevention.