Long-term stroke risk prediction in patients with atrial fibrillation: Comparison of the ABC-stroke and CHA2DS2-VASc scores

Background-the abc-stroke score (age,biomarkers [n-terminal fragment b-type natriuretic peptide,high-sensitivity troponin],and clinical history [prior stroke/transient ischemic attack]) was proposed to predict stroke in atrial fibrillation (af). this score was derived/validated in 2 clinical trial cohorts in which patients with af were highly selected and carefully followed-up. however,the median follow-up was 1.9 years in the trial cohort; therefore,its long-term predictive performance remains uncertain. this study aimed to compare the long-term predictive performances of the abc-stroke and cha2ds2-vasc (cardiac failure or dysfunction,hypertension,age ≥75 [doubled],diabetes mellitus,stroke [doubled]-vascular disease,age 65 to 74 years and sex category [female]) scores in a cohort of anticoagulated patients with af. methods and results-we recruited 1125 consecutive patients with af who were stable on vitamin k antagonists and followed-up for a median of 6.5 years. abc-stroke and cha2ds2-vasc (cardiac failure or dysfunction,hypertension,age ≥75 [doubled],diabetes mellitus,stroke [doubled]-vascular disease,age 65 to 74 years and sex category [female]) scores were calculated and compared. median cha2ds2-vasc and abc-stroke scores were 4 (interquartile range 3-5) and 9.1 (interquartile range 7.3-11.3),respectively. there were 114 ischemic strokes (1.55% per year) at 6.5 years. the c-index of abc-stroke at 3.5 years was significantly higher than cha2ds2-vasc (0.663 versus 0.600,p=0.046),but both c-indexes were nonsignificantly different at 6.5 years. integrated discrimination improvement showed a small improvement (< 2%) in sensitivity at 3.5 and 6.5 years with abcstroke. for abc-stroke,net reclassification improvement was nonsignificantly different at 3.5 years,and showed a negative reclassification at 6.5 years compared with cha2ds2-vasc. decision curve analyses did not show a marked improvement in clinical usefulness of the abc-stroke score over the cha2ds2-vasc score. conclusions-in anticoagulated patients with af followed-up over a long-term period,the novel abc-stroke score does not offer significantly better predictive performance compared with the cha2ds2-vasc score. © 2017 the authors.