Mitral valve replacement in rheumatic patients: effects of chordal preservation.

Background: Subvalvular preservation is beneficial in patients undergoing mitral valve replacement, especially in degenerative mitral regurgitation. Its feasibility and benefit is less evident in rheumatic disease. Our aim was to study the impact of preservation techniques in rheumatic patients and determine risk factors for mortality.

Methods: Five hundred sixty-six rheumatic patients undergoing mitral valve replacement between 1996 and 2006 have been included. One hundred fifty-six patients had complete excision of the subvalvular apparatus (group 1), 248 had preservation of the posterior leaflet (group 2), and 162 had total chordal preservation (group 3). Echocardiography was performed preoperatively, at discharge, at 1 year, and at late follow-up.

Results: Reduction of ventricular volume was greater in groups 2 and 3, especially if previous mitral regurgitation or mixed disease were present. In mitral stenosis, valve resection caused postoperative increase of volume. Ventricular ejection and pulmonary hypertension had better outcome with valve preservation. Valve resection was associated with late mortality (hazard ratio, 2.64; p < 0.05), and complete chordal preservation was protective (hazard ratio, 0.31; p = 0.13). Actuarial survival (130 months) was better in group 3: 77.18% +/- 0.04%, 85.38% +/- 0.03%, and 93.22% +/- 0.02%, respectively (p < 0.01 group 1 versus group 3). Group 1 exhibited more low cardiac output syndrome (p < 0.01) and more patients in New York Heart Association functional class III and IV at last follow-up: 17.8% versus 3.9% and 2.0% (p < 0.001).

Conclusions: Complete chordal preservation is possible in a large percentage of rheumatic patients. Greater decrease of ventricular volume is obtained for mitral regurgitation. In mitral stenosis, subvalvular preservation may avoid postoperative ventricular dilatation. Consequently, ventricular ejection, pulmonary hypertension, and clinical outcomes may improve with time.