Abstract 10623: Validation of Embolic and Bleeding Risk Scores in Patients with Atrial Fibrillation and Cancer

Abstract

Introduction: Atrial fibrillation (AF) is common among cancer patients. Anticoagulation can reduce the risk of stroke and systemic embolism in AF patients. However, anticoagulation in patients with cancer can be difficult given unpredictable changes in thrombosis and bleeding risk. Although CHA 2 DS 2 -VASc and HAS-BLED are useful, their predictive performance in patients with cancer is unknown. Hypothesis: CHA 2 DS 2 -VASc and HAS-BLED scores in AF patients with cancer could lead to misclassification. Methods: Overall, 16,056 AF patients between 2014 and 2018 were followed during a median follow-up of 4.9 years, including 1,137 with cancer history. We used C statistic and Brier score for assessing the performance of both scores. Results: Discrimination, assessed with C statistics (assuming death as a competing risk), was similar between cancer and non-cancer anticoagulated patients. However, in non-anticoagulated patients, c-statistic of CHA 2 DS 2 -VASc was poor and significantly lower in non-cancer patients. The overall precision of the CHA 2 DS 2 -VASc score was good throughout the follow-up (Brier score <0.1), both in patients with and without cancer history. Regarding to HAS-BLED score, calibration and discrimination were poor in cancer patients, although without significant differences in comparison with non-cancer patients. In non-anticoagulated cancer patients and in those with active cancer, the embolic risk of CHA 2 DS 2 -VASc score = 1 was similar to CHA 2 DS 2 -VASc score ≥ 2. Only AF patients with cancer and CHA 2 DS 2 -VASc score = 0 presented a truly low risk of embolic events (negative predictive value 100%). A HAS-BLED score > 3 did not identify AF patients with cancer at higher bleeding risk. Conclusions: In AF patients with cancer, neither the CHA2DS2-VASC score nor the HASBLED score were useful for predicting embolic and hemorrhagic events, respectively. However, a CHA 2 DS 2 -VASc score 0 is useful to identify low embolic risk patients with AF and cancer.