Prognostic value of CHA2DS2-VASc score in patients with ‘non-valvular atrial fibrillation’ and valvular heart disease: the Loire Valley Atrial Fibrillation Project

Abstract

The CHA2DS2VASc score is a clinical risk stratification tool which estimates the risk of stroke and thromboembolism in non-valvular atrial fibrillation (AF). We aimed to establish the value of this score for risk evaluation in patients with non-valvular AF and valvular heart disease. Among 8053 patients with non-valvular AF (ESC guidelines definition), patients were categorized into Group 1 (no valve disease, n = 6851; 85%) and Group 2 (valve disease with neither rheumatic mitral stenosis nor valve prothesis, n = 1202; 15%). After follow-up of 868 ± 1043 days, 627 stroke/ thromboembolic (TE) events were recorded. Group 2 was significantly older, had a higher CHA2DS2VASc score and had a higher risk of thromboembolic events [hazard ratio (HR) 1.39; 95% CI 1.14-1.69, P = 0.001] compared with Group 1. Severe valve disease was not associated with worse prognosis for stroke/TE events. In the two groups, stroke/TE risk increased with a higher CHA2DS2VASc score. Factors independently associated with increased risk of stroke/TE events were older age (HR 1.25, 95% CI 1.14-1.36 per 10-year increase, P < 0.0001) and higher CHA2DS2VASc score (HR 1.33, 95% CI 1.23-1.45, P < 0.0001). The predictive value (c-statistic) of the CHA2DS2VASc score was similar in the two groups. In patients with non-valvular AF, left-sided valvular heart disease (excluding mitral stenosis and protheses) was associated with an increased risk of stroke/TE events. A higher CHA2DS2VASc score in these patients is likely to explain these results.