Papillary Muscle Relocation in Secondary Mitral Regurgitation: Midterm Outcomes

Background: Mitral valve repair in secondary mitral regurgitation is still uncertain as the chance of recurrence is approximately 30 percent after solely undersized annuloplasty. Some procedures adding to the subvalvular level are proposed to alleviate the recurrent rate. This study was to evaluate the clinical and echocardiographic outcomes of papillary muscle relocation plus undersized ring in secondary mitral regurgitation (2 nd MR). Methods: Medical records of moderate to severe 2 nd MR with tethering depth of more than 1 cm patients who underwent papillary muscle relocation plus undersized ring from 2014 to 2020 were reviewed. Clinical and echocardiographic parameters before and after operation were analyzed. Results: Thirty-two patients were included during the 6-year period. There was no perioperative mortality. Two patients died at one year from ischemic stroke and car accidents with overall 5-year survival of 93.7%. All patients were in NYHA class I and II with MR grading as trivial or mild at a median follow-up of 33 months. Postoperative mean tenting depth, area and posterior leaflet angle decreased remarkably from 1.18 cm, 2.61 cm 2 and 46.5 degree to 0.65 cm, 1.22 cm 2 and 28.6 degree, respectively (p < 0.001, 0.02, and 0.01). Moreover, left ventricular function and remodeling were also notably improved (EF; 38.2% vs 49.1%: p = 0.018, LVEDD; 62.8 vs 54.6 mm: p = 0.005, LVESD; 50.2 vs 42.4 mm: p = 0.01). Conclusions: Papillary muscle relocation combined with undersized annuloplasty improved mid-term clinical outcomes. Apart from reduction of recurrent MR rate, restoration of mitral configuration and reverse LV remodeling could be the effect of adding subvalvular correction in this pathology.