In the udenafil group , an echocardiographic surrogate of LV filling pressure was more prominently decreased ( P = @ ) along with a significant reverse remodeling of left atrial volume index ( @ @mL at baseline to @ @ at @th week , P = @ ) and a progressive fall in B-type natriuretic peptide level ( @ @pg/mL at baseline to @ @pg/mL at @th week , P < @ ) , indicating LV diastolic function improvement .