Relative performance evaluation of four bleeding risk scores in atrial fibrillation patients. What does the new DOAC score provide?

BACKGROUND

Recently, the direct oral anticoagulant (DOAC) score was developed and better predicted major bleeding in DOAC-treated patients with atrial fibrillation (AF) than HASBLED did. Little is known on the new score's performance regarding other bleeding risk in AF.

METHODS

We studied 14,672 patients diagnosed with AF between 2014 and 2018. During follow-up, we assessed the performance of DOAC score compared with the HASBLED, ORBIT and SWISS scores at predicting major bleeding in DOACs and non-DOACs users. Discrimination, calibration and decision curve analysis (DCA) were used to assess the risk scorer's performance.

RESULTS

There were 1484 (10.1%) patients on DOACs, 9730 on vitamin K antagonist (VKA), and 3458 on non-oral anticoagulants. Over a median of 3.5 years of follow-up, 79 major bleedings occurred in the DOAC patients, and 486 in the VKA patients (cumulative incidences = 7.4 and 13.9 per 100 patient-years, respectively). Amongst the DOAC patients, the DOAC score discrimination was moderate (C-statistic = 0.711), but significantly higher than HASBLED (C = 0.640; p = 0.03), ORBIT (C = 0.660; p = 0.04), and SWISS scores (C = 0.637; p = 0.002). The DCA showed higher net benefit using DOAC score compared with the remaining scores. In the VKA patients, DOAC score showed the highest discrimination (c-statistic = 0.709), followed by ORBIT (C = 0.692; p = 0.07), HASBLED and SWISS (C = 0.635 and 0.624, respectively; p < 0.01). All risk scores calibrated well, although HASBLED showed relatively poor calibration.

CONCLUSIONS

The new DOAC bleeding risk score is a valid and reasonable predictor of major bleeding over a median of 3.5 years of follow-up. Physicians can be reassured about the applicability of DOAC score for bleeding risk stratification in AF patients.

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CLINICALTRIALS: gov; Unique identifier: NCT04364516.