High prevalence of unrecognized chordae tendineae rupture in mitral valve prolapse patients undergoing valve replacement surgery

Background: Not infrequently, chordae tendineae rupture, which was not recognized preoperatively using echocardiography, was found during mitral valve (MV) surgery in patients with severe mitral regurgitation (MR) diagnosed with MV prolapse. We evaluated the incidence and predictors of echocardiographically-unrecognized chordae tendineae rupture in patients with severe MR because of MV prolapse. Methods: We enrolled 124 patients undergoing MV surgery for severe MR because of nonrheumatic MV prolapse. Patients with MR because of infective endocarditis, ischemic heart disease, or echocardiographically-detected chordal rupture were excluded. The study sample was divided into 2 groups: surgically-proven chordae tendineae rupture (n= 51), and no chordae rupture (n= 73). Results: Echocardiographically-unrecognized chordae tendineae rupture was found in 51 (41%) of 124 patients undergoing MV surgery because of MR. It was more common in patients with posterior or single-leaflet prolapse. Although the severity of MR was greater in patients with chordal rupture, left atrial volume index was smaller compared with those without. In a multivariate analysis, involvement of posterior leaflet (odds ratio [OR], 2.80; 95% confidence interval [CI], 1.15-6.84) or single leaflet (OR, 3.18; 95% CI, 1.07-9.45), MR severity (OR, 4.76; 95% CI, 1.96-11.59), and left atrial volume index (OR, 0.98; 95% CI, 0.96-0.99) were independently associated with chordal rupture (P < 0.05 for all). Conclusions: Unrecognized chordae tendineae rupture is a common unrecognized contributor to severe MR necessitating valve replacement in MV prolapse patients. Earlier recognition and more specific management might contribute to improved prognosis for such patients.