015 The CHADS2 score predicts more accurately adverse cardiovascular outcome in atherothrombotic patients without atrial fibrillation than established scores: Insights from the European REACH registry

AimThe CHADS2 score is a reliable, easy-to-use, and popular bedside score to assess the risk of stroke in patients with atrial fibrillation (AF). The items of the score are all key determinants of prognosis in vascular patients. We compare CHADS2 to established scores (the Framingham score and the European SCORE) for their ability to predict adverse cardiovascular outcome in atherothrombotic patients without AF.MethodsIndividual risk scores were calculated in 18,888 stable atherothrombotic patients without AF included in the European REACH registry in 18 European countries between 2003 and 2004. Each scheme was divided into low, intermediate and high predicted risk categories and applied to the cohort. MACCE (CV Death, MI or Stroke) were recorded at 2 years follow-up.ResultsTwo hundred six deaths and 987 MACCE occurred during 37776 patients-years follow up. According to CHADS2 score, 38.2% (7234 patients with CHADS2=0-1) had low, 48.2% (9101 patients with CHADS2=2-3) had intermediate and 13.5% had high predicted CV risk (2553 patients with CHADS2=4-6) (figure A). The proportion of individual assigned to individual risk categories varied widely across schemes (low risk ranged from 26.6% to 88.6%, high risk from 1.5% to 25.0%). Although the risk scores had only poor discriminating ability, CHADS2 had the higher c-statistics of 0.613 (figure B). In multivariable logistic regression, the CHADS2 score (high vs low risk) remains an independent predictor of MACCE even after adjustement to Framingham score (OR 2.78 [95% CI 2.3 to 3.3]) or european SCORE (OR 2.94 [95% CI 2.45 to 3.5]).ConclusionsThe CHADS2, a reliable, easy-to-use, bedside score, appears to predict more accurately, adverse cardiovascular outcome in atherothrombotic patients without atrial fibrillation, than established scores. But current risk scheme have limited ability and better scores are needed