Does preoperative tethering symmetry affect left ventricular reverse remodeling after restrictive annuloplasty?

Background: We hypothesized that a preoperative symmetric pattern with anterior mitral leaflet (AML) tethering predominance is related to lack of LVRR after restrictive annuloplasty. Methods: In 300 patients with surgical annuloplasty for chronic ischemic mitral regurgitation the AML and posterior mitral leaflet (PML) tethering angles were quantified and patients were divided on the basis of the preoperative anterior/posterior tethering angle ratio: there were 144 patients with symmetric (Group 1) and 156 with asymmetric (Group 2) preoperative tethering pattern patients underwent echocardiography preoperatively, at discharge and at follow-up appointments (6 months [IQR 5-8 months]; late, 48 months [15-63 months]). Reverse remodeling was defined as a reduction in left ventricular end systolic volume index > 15%. Results: LVRR was higher in the asymmetric group at discharge (69.2% vs. 9.7%, p <0.001), early (70.55% vs. 10.45%, p <0.001 and late follow up (81.4% vs. 4.8%, p <0.001). At multivariable regression analysis corrected by significant key factors of LVRR, symmetric leaflet tethering (OR, 4.8 [95% CI 2.9-5.6], p <0.001), anterior tethering angle α′ <39.5° (OR, 5.0 [95% CI 2.0-6.6], p <0.001), coaptation height <11 mm (OR, 2.5 [95% CI 1.1-3.3], p = 0.006) and coaptation length ≥ 8 mm at the end of procedure (OR, 2.0 [CI 0.8-3.0], p = 0.01) were independent predictors of LVRR. Compared with patients with asymmetric pattern (adjusted OR 0.2 [95% CI 0.03-1.6), those with symmetric pattern had > 4-fold odds for lack of LVRR. Conclusions: The preoperative symmetric pattern with AML prevalence was strongly associated with lack of reverse remodeling after annuloplasty. An accurate echocardiographic evaluation of the tethering mechanisms should be incorporated into clinical risk assessment and prediction models.