Contemporary management of atrial fibrillation and the predicted vs. absolute risk of ischaemic stroke despite treatment: a report from ESC-EHRA EORP-AF Long-Term General Registry

Background: Risk stratification in patients with atrial fibrillation (AF) is important to facilitate guideline-directed therapies. The Calculator of Absolute Stroke Risk (CARS) scheme enables an individualized estimation of 1-year absolute risk of stroke in AF. We aimed to investigate the predicted and absolute risks of ischaemic stroke, and evaluate whether CARS (and CHA2DS2-VASc score) may be useful for identifying high risk patients with AF despite contemporary treatment.

Methods: We utilized the EORP-AF General Long-Term Registry which prospectively enrolled patients with AF from 250 centres across 27 participating European countries. Patients with sufficient data to determine CARS and CHA2DS2-VASc score, and reported outcomes of ischaemic stroke were included in this analysis. The primary outcome of ischaemic stroke was recorded over a 2-year follow-up period.

Results: A total of 9444 patients were included (mean age 69.1 [±11.4] years; 3776 [40.0%] females). There was a high uptake (87.9%) of anticoagulation therapy, predominantly with vitamin K antagonist (50.0%). Over a mean follow-up period of 24 months, there were a total of 101 (1.1%) ischaemic stroke events. In the entire cohort, the median CARS and absolute annual risks of ischaemic stroke were 2.60 (IQR 1.60-4.00) and 0.53% (95%CI 0.43-0.64%), respectively. There was no statistical difference between the predictive performance of CARS and CHA2DS2-VASc score (0.621 [95%CI 0.563-0.678] vs. 0.626 [95%CI 0.573-0.680], P = 0.725).

Conclusion: Contemporary management of AF was associated with a low risk of ischaemic stroke. CARS and CHA2DS2-VASc score may be useful to identify high risk patients despite treatment who may benefit from more aggressive treatment and follow-up.