Abstract 14762: Stroke and Thromboembolism in Patients With Atrial Fibrillation and Mitral Regurgitation

Introduction: It has been found in short series in the 1990s that significant mitral regurgitation (MR) might be protective against left atrial spontaneous echo contrast formation and against stroke in patients with non-rheumatic atrial fibrillation (AF). The effect of MR on the risk of stroke in patients with AF is still debated. We studied whether or not MR was associated with a decreased risk of stroke in a large series of patients with non-valvular AF. Methods: Among 8053 patients with nonvalvular AF (ie. no prosthetic valve or mitral stenosis), 740 patients (9%) had MR, among whom 107 (14%) had severe MR. Patients with MR were significantly older and had a higher CHA 2 DS 2 -VASc score. Results: After follow up of 868±1043 days, 627 stroke/ thromboembolic (TE) events were recorded. Patients with MR had a similar risk of thromboembolic events when compared to patients with no MR (unadjusted hazard ratio [HR] 1.19; 95%CI 0.93-1.52, p=0.18, adjusted HR 0.99, 95%CI 0.77-1.28, p=0.95 after adjustment for age, gender, VKA and antiplatelet use and CHA 2 DS 2 -VASc score). Severe MR was associated with a nonsignificant higher risk for stroke/TE events (HR 1.59; 95%CI 0.85-2.98, p=0.14, adjusted HR 1.85, 95%CI 0.95-3.57, p=0.07). In the 2 groups, stroke/TE risk increased with a higher CHA 2 DS 2 -VASc score. Factors independently associated with increased risk of stroke/TE events were older age (HR 1.27, 95%CI 1.17-1.36 per 10-year increase, p 2 DS 2 -VASc score (HR 1.31, 95%CI 1.23-1.39, p Conclusions: In patients with nonvalvular AF, neither MR nor severe MR was independently associated with a different risk of stroke/TE events. The perceived protective effect of MR against the risk of thrombo-embolic events is not relevant in AF patients in relation to risk strata using a contemporary risk stratification scheme, the CHA 2 DS 2 -VASc score.