P1008Clinical characteristics and outcomes of japanese patients with atrial fibrillation and mitral regurgitation: the fushimi af registry

Abstract

Background: Previous studies have suggested that the presence of mitral regurgitation (MR) with atrial fibrillation (AF) may have a protective role in the occurrence of thromboembolic events, and that mild to moderate MR may increase the thromboembolic risk, in contrast to severe MR, which might have a protective effect. The proposed mechanism would be an increase in atrial washing and emptying and reduced intra-atrial stasis, but these suggestions remain controversial. Method: The Fushimi AF Registry was designed to enroll all of the AF patients in our city. In the entire cohort (4,325 patients), we excluded 169 patients (3.9%) who were classified into valvular AF (defined as either rheumatic mitral stenosis or prosthetic heart valves) or uncertain about valvular heart disease. The eligible 4,156 patients were divided into MR group (n=393, 9.5%) and non-MR group (n=3,763, 90.5%). Result: MR group was more older (MR vs. non-MR; 75.7 years vs. 73.3 years p<0.0001), more often female (51.4% vs. 38.5%, p<0.0001), persistent/permanent type (71.5% vs. 48.0%, p<0.0001), less in body weight (54.4 kg vs. 60.2 kg, p<0.0001), more likely to have heart failure (53.4% vs. 22.8%, p<0.0001) previous stroke/systemic embolism (SE) (25.2% vs. 19.9%, p=0.013), had higher CHADS2 score (2.45 vs. 1.98, p<0.0001), and received oral anticoagulant prescription more frequently (65.1% vs. 53.2%, p<0.0001). MR group had larger left atrium (48.5 mm vs. 42.6 mm, p<0.0001), and lower left ventricular ejection fraction (58.9% vs. 63.4%, p<0.0001). Heart rate (79.4 bpm vs. 78.3 bpm, p=0.16) was comparable between the groups. During the median follow-up of 1,271 days, the incidence rates of stroke/SE (1.52 vs. 1.44 per 100 person-years, log-rank p=0.95, Figure), ischemic stroke (1.02 vs. 0.99, p=0.91) and major bleeding (1.69 vs. 1.19, p=0.35) were not significantly different between MR and non-MR group. All-cause death was significantly higher in MR group (5.67 vs. 3.51, p=0.0005).We further divided the MR group by the severity of MR using echo-Doppler imaging. Of the MR group, echo-Doppler imaging data were available in 173 patients, and we divided them into two groups; mild to moderate MR (n=121, 69.9%), and severe MR (n=52, 30.1%). Incidence rates of stroke/SE were not significantly different between the three groups (mild to moderate MR vs. severe MR vs. non-MR; 1.85 vs. 3.06 vs. 1.44, p=0.34), and so were ischemic stroke (1.04 vs. 1.67 vs. 0.99, p=0.83). Conclusion: Incidences of stroke/SE and ischemic stroke in MR group were not significantly different from those in non-MR group in Japanese patients with atrial fibrillation. The severity of MR was also not associated with the risk of those thromboembolic events. (Figure Presented) .