Abstract 15523: Absence of Chordae Tendineae near Valve Coaptation Leads to Mitral Regurgitation in Lone Atrial Fibrillation

Abstract

Introduction: Mitral annuloplasty is performed to treat mitral valve regurgitation (MR) in lone atrial fibrillation (AF) patients. The mechanisms of the significant MR in lone AF patients are not known well. We assessed the hypothesis that absence of chordae tendineae near the mitral valve (MV) coaptation could lead to the significant functional MR in the lone AF patients. Methods: We analyzed 64 patients with a history of AF with greater than 50 % of the left ventricular (LV) ejection fraction, and no organic abnormality of MV. Of these 31 has mild or lesser MR (AF Groups) and 33 has moderate or severe MR (AFMR Group). We also analyzed 33 sinus rhythm patients with normal echocardiographic findings (Sinus Group). Parameters concerning to MV morphology were measured with commercial software. Chordae attaching points (CAPs) nearest from the coaptation line were detected on the anterior mitral leaflet (Figure). Ratio of the length from CAP to coaptation line against that from anterior annulus to coaptation line was calculated as CAP-C/An-C ratio. Results: Mitral annular area (P < 0.05), leaflets surface area (P < 0.05), and CAP-C/An-C ratio (P < 0.05) were larger in the AFMR Group as compared with the AF Group (Table). With multivariate analysis, the correlation factor of significant MR in AF patients was increase in the CAP-C/An-C ratio (Odds ratio (per 1 % increase) = 1.70; p <0.05). Conclusion: The absence of chordae tendineae near the coaptation line represented by larger CAP-C/An-C ratio is related to the functional MR in AF patients with normal LV function.