Growth Differentiation Factor-15 Based ABC (Age, Biomarkers, Clinical History)-AF (Atrial Fibrillation)-Bleeding Risk Score for Elderly Patients with Nonvalvular Atrial Fibrillation.

Background: Growth differentiation factor-15 (GDF-15) is a strong predictor of bleeding in atrial fibrillation (AF) patients. The novel ABC (age, biomarkers, and clinical history), AF, and bleeding risk score outperforms HAS-BLED bleeding risk score for major bleeding (MB) in patients with AF receiving oral anti-coagulation in the clinical trial cohort. However, it has not been entirely externally validated. We aimed to refine and understand the application of the ABC-AF bleeding risk score in elderly (aged ≥65 years old) patients with nonvalvular atrial fibrillation (NVAF) for predicting the different types of bleeding events and anti-thrombotic treatments. Methods: We identified elderly patients with NVAF between March 2018 and December 2019 who were hospitalized for the first time after a diagnosis of NVAF. We measured the plasma concentration of the ABC biomarkers (growth differentiation factor 15 (GDF-15) and cardiac troponin-T (cTnT)) from enrolled patients. We collected their general information and follow up for one year until December 2020. During the follow-up period, information on the occurrence of bleeding events (major bleeding, clinically relevant nonmajor gastrointestinal bleeding (CRNM GIB), and minor bleeding events) was collected. Results: We enrolled 342 elderly NAVF patients; the ABC-AF bleeding and HAS-BLED scores were quantified. With an average of 1.5 years of follow-up, 6 patients had an intracranial hemorrhage; 57 patients had CRNM GIB; and 68 patients had minor bleeding events (36 fecal occult blood positive and 32 other minor bleeding events). The ABC-AF bleeding score yielded a C-index of 0.72 (95% CI 0.60-0.84) for predicting MB in elderly patients with NAVF, C-index of 0.69 (95% CI 0.57-0.82) by HAS-BLED score. Comparison of the incidence of bleeding events during follow-up and the predicted 1-year incidence of bleeding events by each bleeding risk score, ABC-AF bleeding, and HAS-BLED scores have similar value in predicting the risk for elderly patients with NAVF in different types of bleeding events, whether on oral anti-coagulation treatment (OAC) or non-OAC (P > 0.05). Conclusion: In elderly patients with NVAF, the biomarker-based ABC-AF bleeding score showed similar performance compared with the HAS-BLED bleeding risk score.