Stroke risk prediction in patients with atrial fibrillation with and without rheumatic heart disease

AIMS: Patients with atrial fibrillation (AF) and rheumatic heart disease (RHD), especially mitral stenosis, are assumed to be at high risk of stroke, irrespective of other factors. We aimed to re-evaluate stroke risk factors in a contemporary cohort of AF patients. METHODS AND RESULTS: We analysed data of 15 400 AF patients presenting to an emergency department and who were enrolled in the global RE-LY AF registry, representing 47 countries from all inhabited continents. Follow-up occurred at 1 year after enrolment. A total of 1788 (11.6%) patients had RHD. These patients were younger (51.4±15.7 vs. 67.8±13.6 years), more likely to be female (66.2% vs. 44.7%) and had a lower mean CHA2DS2-VASc score (2.1±1.7 vs. 3.7±2.2) as compared to patients without RHD (all P<0.001). Significant mitral stenosis (average mean transmitral gradient 11.5±6.5 mmHg) was the predominant valve lesion in those with RHD (59.6%). Patients with RHD had a higher baseline rate of anticoagulation use (60.4% vs. 45.2%, P<0.001). Unadjusted stroke rates at 1 year were 2.8% and 4.1% for patients with and without RHD, respectively. The performance of the CHA2DS2-VASc score was modest in both groups [stroke at 1 year, c-statistics 0.69, 95% confidence interval (CI) 0.60-0.78 and 0.63, 95% CI 0.61-0.66, respectively]. In the overall cohort, advanced age, female sex, prior stroke, tobacco use, and non-use of anticoagulation were predictors for stroke (all P<0.05). Mitral stenosis was not associated with stroke risk (adjusted odds ratio 1.07, 95% CI 0.67-1.72, P=0.764). CONCLUSION: The performance of the CHA2DS2-VASc score was modest in AF patients both with and without RHD. In this cohort, moderate-to-severe mitral stenosis was not an independent risk factor for stroke.