Reduction of mitral valve leaflet tethering by procedures targeting the subvalvular apparatus in addition to mitral annuloplasty.

BACKGROUND: Ischemic mitral regurgitation (IMR) with ischemic cardiomyopathy (ICM) was treated with surgical procedures, and mitral leaflet tethering was assessed. Twenty-two patients with both ICM (left ventricular ejection fraction <0.35) and IMR (>2) underwent coronary artery bypass grafting (CABG), mitral annuloplasty (MAP) with or without surgical ventricular restoration (SVR) and procedures targeting the subvalvular apparatus. METHODS AND
RESULTS: Fourteen patients (group 1) underwent CABG and MAP, and the remaining 8 (group 2) underwent CABG, MAP, SVR, papillary muscle approximation (PMA), and papillary muscle suspension (PMS). PMA joined the entire papillary muscles with 3 mattress sutures. For PMS, 2 ePTFE sutures were placed between papillary muscle tips and fibrous annuli. Anterior and posterior mitral leaflet tethering angles (ALA and PLA) relative to the line connecting annuli, posterior and apical displacement of coaptation, and IMR grade were measured on echocardiography. Although preoperative ALA and PLA in group 2 were significantly larger than in group 1, there was no significant difference between groups at 1 month after surgery. At 1 year after surgery, however, the situation reversed: ALA and PLA in group 1 were significantly larger than in group 2.
CONCLUSIONS: In addition to MAP, procedures targeting the subvalvular apparatus including PMA and PMS achieved persistent reduction of mitral valve leaflet tethering, which might lead to the improvement of long-term outcome.