Ventricular performance following valve replacement for chronic mitral regurgitation: importance of chordal preservation.

OBJECTIVE: To assess immediate and late changes in left ventricular performance after mitral valve replacement (MVR) for mitral regurgitation with or without preservation of chordae tendineae. EXPERIMENTAL DESIGN: a prospective, one year follow-up, study. SETTING: university cardiosurgical hospital. PATIENTS: Fourteen patients with symptomatic chronic mitral regurgitation were divided into Group A (n = 7), which underwent MVR with chordal preservation, and Group B (n = 7) which underwent MVR with chordal transection. METHODS: Transesophageal echocardiography, obtained simultaneously with radial artery and pulmonary capillary wedge pressures over a range of loading conditions, was used to estimate left ventricular elastance (Eps), calculated as the slope of peak systolic pressure/end-systolic volume relation, and preload recruitable stroke work (PRSW). Measurements were taken intraoperatively before and after cardiopulmonary bypass, 6 hours later and 10 days later. Transthoracic echocardiography follow-up data were obtained after 3 months and one year. RESULTS: Eps significantly decreased immediately after MVR (p = 0.018), with no difference among 2 groups. Eps gradually increased to preoperative levels 10 days after surgery. PRSW also significantly decreased after MVR (p = 0.01). The decrease was significantly larger in Group B (p = 0.038). During follow-up, Group A showed a significantly better ejection fraction (p = 0.008), and a smaller end-systolic volume index (p = 0.01) and left ventricular mass index (p = 0.04), than Group B. CONCLUSIONS: These data support the hypothesis that chordal preservation during MVR has beneficial effects on left ventricular performance.