Aims: Isolated sinus node dysfunction (ISND) is a sinus node dysfunction without atrial fibrillation. A high risk of ischaemic stroke (IS) has been reported in ISND populations. However, current guidelines do not recommend anticoagulation in ISND management. P-wave indicates ISND-related atrial remodelling. P-wave indices and the CHA2DS2-VASc score may contribute to risk stratification for ISND-related IS.
Methods and results: In this multi-centre longitudinal cohort, ISND patients were divided into development (n = 1185) and external validation (n = 988) cohorts. Ischaemic stroke prediction capacity of the P-combined score was assessed with regard to discrimination, calibration, and clinical effectiveness. The cut-off value of the score was confirmed by using a restricted cubic spline curve. One hundred and twenty-four (10.46%) ISND patients developed IS [1.63%/year; 95% confidence interval (CI): 1.49-1.78%/year] after a median 3.02-year follow-up in the development cohort. The P-wave terminal force in electrocardiogram-lead V1 (PTFV1) was the only significantly abnormal P-wave index (adjusted hazard ratio: 2.56; 95% CI: 1.72-3.80). Therefore, we incorporated the PTFV1 with the CHA2DS2-VASc score to generate a P-combined score. For a 5-year IS risk, the P-combined score improved Harrell's C-statistic (95% CI) from 0.678 (0.618-0.738) to 0.716 (0.657-0.774) and 0.747 (0.677-0.816) to 0.808 (0.747-0.868) in the development and validation cohorts, respectively, along with calibration and decision curve analyses. The cut-off value of the score was 3 in the development cohort and well-discriminated in the validation cohort.
Conclusion: Chinese ISND patients have a higher IS risk than the general population. Compared with the CHA2DS2-VASc score, the PTFV1-combined CHA2DS2-VASc score shows a better risk-stratification capacity for ISND-related IS.
Keywords: CHA2DS2-VASc score; Ischaemic stroke; P-wave terminal force in ECG-lead V1; Sinus node dysfunction.
By screening the risk factors of ischaemic stroke for isolated sinus node dysfunction (sinus node dysfunction without atrial fibrillation), we developed and validated a new scoring system—P-combined score, which is a combination of an abnormal P-wave terminal force in electrocardiogram-lead V1 (PTFV1) and the CHA2DS2-VASc score. We constructed the P-combined score in the following way: abnormal PTFV1 (2 points), age (1 point for 65–74 years and 2 points for ≥75 years), sex (1 point for female), congestive heart failure (1 point), hypertension (1 point), diabetes mellitus (1 point), vascular disease (1 point), and thrombotic event (2 points). Based on our analysis, we found that the P-combined score showed a strong performance (with a C-statistic of 0.716 for 5 years), which was better than the CHA2DS2-VASc score (C-statistic of 0.678 for 5 years). We also found that the performance of the P-combined score was rigorous in an independent cohort from two external centres (with a C-statistic of 0.808 for 5 years) and outperformed the CHA2DS2-VASc score (C-statistic of 0.747 for 5 years).
© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.