title: The ABC (age, biomarkers, clinical history) stroke risk score: a biomarker-based risk score for predicting stroke in atrial fibrillation.
abstract: Atrial fibrillation (AF) is associated with an increased risk of stroke, which is currently estimated by clinical characteristics. The cardiac biomarkers N-terminal fragment B-type natriuretic peptide (NT-proBNP) and cardiac troponin high-sensitivity (cTn-hs) are independently associated with risk of stroke in AF. Our objective was to develop and validate a new biomarker-based risk score to improve prognostication of stroke in patients with AF.
  
  
  
  A new risk score was developed and internally validated in 14 701 patients with AF and biomarkers levels determined at baseline, median follow-up of 1.9 years. Biomarkers and clinical variables significantly contributing to predicting stroke or systemic embolism were assessed by Cox-regression and each variable obtained a weight proportional to the model coefficients. External validation was performed in 1400 patients with AF, median follow-up of 3.4 years. The most important predictors were prior stroke/transient ischaemic attack, NT-proBNP, cTn-hs, and age, which were included in the ABC (Age, Biomarkers, Clinical history) stroke risk score. The ABC-stroke score was well calibrated and yielded higher c-indices than the widely used CHA2DS2-VASc score in both the derivation cohort (0.68 vs. 0.62, P < 0.001) and the external validation cohort (0.66 vs. 0.58, P < 0.001). Moreover, the ABC-stroke score consistently provided higher c-indices in several important subgroups.
  
  
  
  A novel biomarker-based risk score for predicting stroke in AF was successfully developed and internally validated in a large cohort of patients with AF and further externally validated in an independent AF cohort. The ABC-stroke score performed better than the presently used clinically based risk score and may provide improved decision support in AF.
  
  
  
  NCT00412984, NCT00799903.
authors.affiliation: Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden Uppsala Clinical Research Center, Uppsala University, Uppsala Science Park, Uppsala, Sweden ziad.hijazi@ucr.uu.se.
authors.forename: Ziad
authors.initials: Z
authors.lastname: Hijazi
authors.affiliation: Uppsala Clinical Research Center, Uppsala University, Uppsala Science Park, Uppsala, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Lindbäck
authors.affiliation: Duke Clinical Research Institute, Duke Medicine, Durham, NC, USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Alexander
authors.affiliation: Bristol-Myers Squibb, Princeton, NJ, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Hanna
authors.affiliation: Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden Uppsala Clinical Research Center, Uppsala University, Uppsala Science Park, Uppsala, Sweden.
authors.forename: Claes
authors.initials: C
authors.lastname: Held
authors.affiliation: Boston University Medical Center, Boston, MA, USA.
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Hylek
authors.affiliation: Duke Clinical Research Institute, Duke Medicine, Durham, NC, USA.
authors.forename: Renato D
authors.initials: RD
authors.lastname: Lopes
authors.affiliation: Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden Uppsala Clinical Research Center, Uppsala University, Uppsala Science Park, Uppsala, Sweden.
authors.forename: Jonas
authors.initials: J
authors.lastname: Oldgren
authors.affiliation: Uppsala Clinical Research Center, Uppsala University, Uppsala Science Park, Uppsala, Sweden Department of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden.
authors.forename: Agneta
authors.initials: A
authors.lastname: Siegbahn
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital and University of Auckland, Auckland, New Zealand.
authors.forename: Ralph A H
authors.initials: RA
authors.lastname: Stewart
authors.affiliation: Green Lane Cardiovascular Service, Auckland City Hospital and University of Auckland, Auckland, New Zealand.
authors.forename: Harvey D
authors.initials: HD
authors.lastname: White
authors.affiliation: Duke Clinical Research Institute, Duke Medicine, Durham, NC, USA.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Granger
authors.affiliation: Department of Medical Sciences, Cardiology, Uppsala University, Uppsala, Sweden Uppsala Clinical Research Center, Uppsala University, Uppsala Science Park, Uppsala, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Wallentin
mesh_terms: D001281:Atrial Fibrillation; D015415:Biomarkers; D006801:Humans; D008487:Medical History Taking; D020097:Natriuretic Peptide, Brain; D018570:Risk Assessment; D012307:Risk Factors; D020521:Stroke
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain
keywords: Atrial fibrillation; Biomarkers; Natriuretic peptides; Risk score; Stroke; Troponin