Comparison of mitral competence after mitral repair with papillary muscle approximation versus papillary muscle relocation for functional mitral regurgitation

The purpose of this study was to evaluate the surgical results of papillary muscle approximation (PMA) and papillary muscle relocation (PMR) for functional mitral regurgitation (FMR) and to compare the effects of both procedures on the change in mitral regurgitation (MR) and echocardiogram parameters associated with tethering. Eighteen patients with moderate-to-severe FMR (MR grade ≥2) who underwent PMA or PMR were retrospectively analyzed. Underlying diseases were ischemic cardiomyopathy, idiopathic dilated cardiomyopathy, and aortic valve disease for seven, six, and five patients, respectively. Eleven patients underwent PMA and seven patients underwent PMR. Mitral annuloplasty and surgical ventricular restoration were performed concomitantly for 18 and 6 patients, respectively. None of these patients died in the hospital. Three patients died during the late period; two of these deaths were cardiac related. The rate of 3 years of freedom from cardiac-related death was 89%. After a mean follow-up of 33 months, MR grade was significantly improved compared with preoperative values (3.0 ± 0.8 to 0.7 ± 1.2; p < 0.01). Recurrence of MR grade ≥2 occurred in three patients and the rate of 3 years of freedom from recurrence of MR grade ≥2 was 87%. During follow-up, tenting height (1.1 ± 0.2 to 0.7 ± 0.2 cm; p < 0.01), tenting area (2.2 ± 0.7 to 0.9 ± 0.5 cm2; p < 0.01), and anterior leaflet tethering angle (39° ± 11° to 26° ± 8°; p < 0.01) were significantly improved compared with preoperative values. Posterior leaflet tethering angle significantly deteriorated from 40° ± 7° to 53° ± 15° (p < 0.01); however, it did not further deteriorate compared with the early postoperative value of 55° ± 16° (p = 0.7). There was no difference in echocardiogram parameters associated with tethering between PMA and PMR throughout the observation period. Both methods were associated with lasting relief of MR and reverse left ventricular remodeling. There was no difference between PMA and PMR regarding the effect on mitral valve competence. Both methods allowed durable mitral repair and good clinical outcomes.