The Rate of Clinical Outcomes in Atrial Fibrillation according to Antithrombotic Strategy: The COOL-AF Registry

Net clinical benefit of oral anticoagulants in Asian patients with atrial fibrillation based on a CHA2DS2-VASc score

BACKGROUND

This study was conducted to assess the net clinical benefit (NCB) for oral anticoagulant (OAC) in atrial fibrillation (AF) patients according to the CHA2DS2-VASc score.

METHODS

Patients with AF were prospectively recruited in the COOL AF Thailand registry from 2014 to 2017. The incidence rate of thromboembolic (TE) events and major bleeding (MB) was calculated. Cox proportional hazards model was used to compare the TE and MB rate in patients with and without OACs in CHA2DS2-VASc score of 0-1 and ≥ 2, respectively. The survival analysis was performed based on CHA2DS2-VASc score. The NCB of OACs was defined as the TE rate prevented minus the MB rate increased multiplied by a weighting factor.

RESULTS

A total of 3,402 AF patients were recruited. An average age of patients was 67.38 ± 11.27 years. Compared to non-anticoagulated patients, the Kaplan Meier curve showed anticoagulated patients with CHA2DS2-VASc score of 2 or more had the lower thromboembolic events with statistical significance (p = 0.043) and the higher MB events with statistical significance (p = 0.018). In overall AF patients, there were positive NCB in warfarin patients with CHA2DS2-VASc score of 3 or more while there were positive NCB in DOACs patients regardless of CHA2DS2-VASc score. Females with CHA2DS2-VASc score of 3 or more had a positive NCB regardless of OACs type. Good anticoagulation control (TTR ≥65%) improved an NCB in males with CHA2DS2-VASc score of 3 or more.

CONCLUSIONS

AF patients with CHA2DS2-VASc score of 3 or more regardless warfarin or DOACs had a positive NCB. The NCB of OACs was more positive for DOACs compared to warfarin and for females compared to males.