Compared with the symmetric group , the asymmetric group had less annular dilatation , greater annular heights ( 10.3 1.9 vs 8.5 1.9 mm , P < .01 ) , greater ratios of posterior to anterior leaflet tethering angle ( 3.19 0.88 vs 1.95 0.46 , P < .01 ) , and smaller TVs with more posterior displacement of the coaptation line .