Long-term outcomes of papillary muscle relocation anteriorly for functional mitral regurgitation

Objectives: This study aimed to evaluate the outcomes of the patients who underwent restrictive annuloplasty (RA) plus papillary muscle relocation anteriorly (PMR-A) with the risk factors in mitral valve repair for functional mitral regurgitation (FMR).

Methods: Eighty-six patients underwent mitral valve repair with RA for FMR. Thirty-five of them received additional bilateral papillary muscle relocation for severe leaflet tethering. The papillary muscles were relocated posteriorly (PMR-P) early in the study. Then, in the later period, the technique was modified to PMR-A, in which the papillary muscles were relocated anteriorly for 24 cases. The survival of the patients undergoing RA + PMR-A was examined retrospectively, adjusting for differences in patient background.

Results: Twenty-three deaths were observed during the follow-up period out of the 86 cases. Independent preoperative risk factors for survival were left ventricular ejection fraction, patient age and B-type natriuretic peptide (BNP) level. Among the patients with BNP <1000 pg/ml, 5-year survival after RA plus PMR-A was 84.7%, while RA alone was 78.6% and RA + PMR-P 57.1%. Cox proportional hazards regression adjusted for the preoperative risk factors showed a significantly higher hazard ratio of RA + PMR-P to RA + PMR-A (12.77, P = 0.011), while the hazard ratio of RA alone to RA + PMR-A was not significantly different. Furthermore, reverse remodelling of the left ventricle was observed for 3 years only in RA + PMR-A.

Conclusions: Long-term survival for patients who underwent RA plus bilateral PMR-A was promising. Patients with significantly higher BNP had lower survival after valve repair for FMR.