Late development of mitral regurgitation after left ventricular reconstruction surgery

Late presence of mitral regurgitation (MR) after the Dor procedure (left ventricular (LV) reconstruction associated with coronary artery bypass grafting) for postinfarction patients carries a poor prognosis. The aim of this study was to review our experience with the Dor procedure and to analyze the correlation of surgical results with late MR.

The study group comprised 19 patients with previous anterior transmural myocardial infarction (MI). Ten patients were classified as New York Heart Association (NYHA) functional class III or IV at surgery. MR was moderate in 2 patients and mild in 15 patients.

Myocardial revascularization was performed in all patients, with a mean of 3.7+/-1.2 grafts. Mitral valve was repaired in 6 patients. Four patients with mild MR underwent posterior annuloplasty, and 2 with moderate MR underwent rigid annular remodeling. Early postoperative NYHA functional class improved from 2.7+/-0.9 to 1.3+/-0.5; however, MR deteriorated to moderate in 5 patients with worsening NYHA functional class 3 months after surgery. Although the valve was not repaired during surgery in 4 patients with preoperative mild MR, 1 patient with moderate MR underwent annuloplasty with a rigid ring. All patients with late MR underwent more than 30-mL/m2 reduction of end-diastolic volume index at surgery. Cumulative 4-year survival including hospital deaths was 89.5%.

To prevent the risk of late MR, a more than 30-mL/m2 reduction of end-diastolic volume index should be avoided and mitral valve repair should be performed even if preoperative functional MR is only mild.