After 6 months of therapy , an improvement in clinical status ( WHO functional class 2.1 0.4 vs 2.9 0.3 ; P = 0.042 ) , 6-minute walk distance ( 360 51 vs 293 68 m ; P = 0.005 ) , SpO ( 2 ) at the end of the 6MWT ( 72 10 vs 63 15 % ; P = 0.047 ) , Borg score ( 2.9 1.5 vs 4.4 2.3 ; P = 0.036 ) , serology ( pro-brain natriuretic peptide 303 366 vs 760 943 pg/ml ; P = 0.008 ) and haemodynamics ( pulmonary blood flow 3.4 1.0 vs 3.1 1.2 l/min/m ( 2 ) , P = 0.002 ; pulmonary vascular resistances index 19 9 vs 24 16 WU/m ( 2 ) , P = 0.003 ) was observed .
