Background: The aim of this study is to investigate the feasibility of chordal-sparing mitral valve replacement procedures in a rheumatic population, and to determine the early and late effects of different chordal preservation procedures on the clinical outcome and left ventricular mechanics.
Methods: Various techniques of chordal preservation during mitral valve replacement for rheumatic heart disease in 451 patients between 1996 and 1999 are described. The mean age was 35.6 +/- 19.0 years (range, 15 to 55 years). Seventy patients had complete excision of the subvalvular apparatus (group I), 124 had preservation of the posterior chordopapillary apparatus (group II), and 257 had total chordal preservation (group III). Echocardiography was performed preoperatively, at discharge, at 1 year, and at 4 years.
Results: Chordal preservation groups (II and III) demonstrated significant improvement (p < 0.05) in left ventricular function immediately and late postoperatively. Reduction of left ventricular end-systolic and end-diastolic volume was significant in the chordal preservation groups (II and III) as compared to the nonchordal group (group I; p < 0.005). The total chordal group demonstrated greater fractional change of left ventricular end-systolic volume as compared to the posterior chordal and nonchordal group. The left ventricular ejection fraction and fractional shortening continued to decline over time in the nonchordal cohort (p = 0.05 and p = 0.001, respectively) and did not improve by 4 years. Statistically significant change in ejection fraction occurred in the chordal preservation groups as compared to the nonchordal group.
Conclusions: We conclude that total chordal preservation is possible in the large majority of rheumatic patients and confers significant long-term advantage by preserving left ventricular function. The surgical technique should be individualized.