For a comprehensive review of bleeding risk factors in AF patients see Zulki y et al.103 The bleeding risk scores range in the simplicity of calculation and the cutoffs employed to indicate low, intermediate, and high risk of bleeding, and the prevalence of bleeding events reported in the validation cohorts (Table 3). Use of Bleeding Risk Scores: As seen in Table 3, there are multiple bleeding risk scores that have been proposed for bleeding risk strati cation, with the HEMORR2HAGES (hepatic or renal disease, ethanol abuse, malignancy, older, reduced platelet count/ function, hypertension, anemia, genetic factors, excessive fall risk, and stroke), HAS-BLED (hypertension, abnormal renal/liver function [1 point each], stroke, bleeding history or predisposition, labile INR, elderly (0.65), drugs/alcohol concomitantly [1 point each]), ATRIA, ORBIT, and ABC-bleeding derived and validated in AF populations.103 The risk factors included vary by scores (Table 3), and their derivation from selected clinical trial cohorts or real- Various validation studies have been summarized in e-Table 10. Unsurprisingly, stroke risk scores are also associated with bleeding, as stroke and bleeding risks correlate with each other. For example, higher CHADS2 and CHA2DS2-VASc scores are also associated with greater bleeding risk, but the HAS-BLED score outperforms the CHADS2 and CHA2DS2-VASc scores for predicting which was also evident in the systematic review by Zhu et al.106 Composite risk scores that include stroke and bleeding end points have also been proposed but have not been shown to perform incrementally better over the individual scores.107,108 The bleeding risk scores in AF are also predictive of bleeding in non-AF populations; for example, in patients with ACS undergoing PCI-stenting.109 Adding more clinical variables marginally improves the predictive value (at least statistically), but the c-indexes still remain approximately 0.6. 