Higher baseline LVEF ( odds ratio , 0.90 [ 95 % confidence interval , 0.86 , 0.95 ] ; P < 0.0001 ) and previous permanent pacemaker ( odds ratio , 0.34 [ 95 % confidence interval , 0.15 , 0.81 ] ) were independently associated with reduced likelihood of 10 % absolute LVEF improvement by 30 days ; higher mean aortic valve gradient was associated with increased odds of LVEF improvement ( odds ratio , 1.04 per 1 mm Hg [ 95 % confidence interval , 1.01 , 1.08 ] ) .