By 30 days after TAVR , mean aortic valve gradient had decreased ( from 43.8 14.7 to 10.0 4.3 mm Hg , P < .001 ) , ejection fraction had increased ( from 53.2 12.4 % to 56.7 10.0 % , P < .001 ) , and left ventricular ( LV ) mass index had decreased ( from 144.7 36.1 to 140.0 37.9 gm/m ( 2 ) , P < .05 ) .