Abstract 12418: Effect of Atrial Fibrillation Cardioversion on the Severity of Mitral Insufficiency

To evaluate the effect of cardioversion with restoration of sinus rhythm in patients with atrial fibrillation (AF) and significant mitral regurgitation (MR) may improve the severity of MR. Atrial fibrillation (AF) is chronic, progressive and, may cause "permanent remodeling of the heart muscle, without structural abnormalities of the valve, reverse remodeling of the left atrium (LA) may be successful in AF. This retrospective cohort study included patients with atrial fibrillation who were hospitalized for cardioversion, received echocardiography during AF in mitral insufficiency, demonstrated significant mitral regurgitation, and underwent additional echocardiography within six months. Indices of the two echocardiograms were compared and used to investigate the effect of cardioversion on the severity of MR. A total of 417 patients were enrolled with a mean age of 74.6 ± 12, with 192 men (46%). On a 6 month follow-up echo, 254 patients (61%) returned to sinus rhythm. An improvement of two or more degrees of severity of MR was observed in 100 patients (24%). Of that number, 72 patients (72%) returned to sinus rhythm, compared with 28 patients (28%) who remained in AF (p = 0.009). Multivariate analysis found that the restoration of sinus rhythm was independently associated with an improvement of two or more degrees of severity, MR p = 0.01, OR = 1.9, CI 95% [1.2-3.0]. There was improvement in the end systolic left ventricular diameter from 3.79 ± 0.99 to 3.58 ± 0.91, p < 0.01, a decrease in the diameter of the left atrium from 4.97 ± 0.64 to 4.79 ± 0.76, p < 0.02, a decrease in the jet area from 11.37 ± 3.7 to 5.9 ± 1.7, p < 0.01, a decrease in vena contracta from 0.66 ± 0.08 to 0.56 ± 0.07, p < 0.01, and a decrease in the TIG from 41.85 ± 12.9 to 36.5 ± 10.7, p < 0.01. There was also an improvement in the FS indices from 28.70 ± 10.17 to 32.17 ± 9.28, p < 0.01.In the group with a slight improvement or no improvement in MR, there was an increase in end diastolic diameter from 5.10 ± 0.77 to 5.19 ± 0.79, p < 0.02, and an increase in the diameter of the left atrium. There was no difference in the other indices. Cardioversion of atrial fibrillation to sinus rhythm in patients with significant mitral regurgitation was positively related to improvement in the severity of mitral insufficiency.