Evaluation of the C₂HEST Risk Score as a Possible Opportunistic Screening Tool for Incident Atrial Fibrillation in a Healthy Population (From a Nationwide Danish Cohort Study)

A simple clinical score, C2HEST (C2: CAD/COPD [1 point each]; H: Hypertension; E: Elderly [Age ≥75, doubled]; S: Systolic HF [doubled]; T: Thyroid disease [hyperthyroidism]) has been proposed to predict incident atrial fibrillation (AF), with good discrimination and internal calibration. To define high-risk patients at particular age strata for incident AF in a nationwide population cohort, who could potentially be targeted for AF screening, we used a nationwide cohort study of all Danish citizen aged ≥65 years to evaluate the performance of the C2HEST score. "High risk" subjects at age 65, 70, and 75 had 5-year risks of new onset AF of 11.8%, 14.2% and 13.6%, respectively, and the corresponding event rates were 2.99, 3.67, and 3.38 per 100 person years, respectively. Associated hazard ratios (HR) were 4.08 (95% confidence interval [CI] 3.84 to 4.34), 3.80 (95% CI: 3.68 to 3.92) and 2.17 (95% CI: 2.13 to 2.22), respectively compared with the lowest risk strata within age category. At all age cohorts, the greatest risk component of the C2HEST score on multivariable analysis was by having 2 points for C (C2), that is both CAD and COPD followed by systolic heart failure (S) both with HRs up to 2.0. CAD or COPD alone (C1) or hypertension (H) were associated with increased risk of new onset AF corresponding to HR between 1.44 and 1.64. In conclusion, this nationwide population cohort addresses the question on clinical risk prediction for new onset AF in a population at different age strata, whereby the C2HEST score may help in identifying those at 'high risk' of new onset AF at 3 distinct age cohorts (65, 70, and 75 years). A high risk C2HEST score stratum was associated with a greater risk of new onset AF. These patients could be considered for more intensive efforts for screening and detection of incident AF.