Right ventricle (RV) fibrosis is known to worsen outcomes in patients with pulmonary hypertension (PH). The aim of this study was to evaluate how RV stiffness, measured by transthoracic echocardiography, was associated with proven risk factor of high mortality in patients with PH – NTproBNP.
Materials and methods.
We included 30 subjects with PH: 13,3% (n=4) with idiopathic PH, 3,3% (n=1) with PH associated with portal hypertension, 70% (n=21) with PH associated with congenital heart disease and 13,3% (n=4) with chronic thromboembolic PH. We used physical examination and echocardiography with extended evaluation of RV stiffness – RV end systolic elastane (Ees), artery afterload elastance (Ea), RV ventricle-arterial coupling (VAC) and global longitudinal strain of RV (RV SR). Each subject was treated with sublingual sildenafil 20 mg 3 times a day for 6 months. NTproBNP tests were done at the beginning and in the end of a study. In order to find association, we used Spearman correlation analysis.
Mean pulmonary artery systolic pressure (PASP) was 89.21±4.46 mmHg according to the right heart cath results, most patients belonged to the II functional class and were stable at the moment of inclusion. Mean echocardipographic values were: systolic pressure in pulmonary artery 75,50±6,59 mmHg, TAPSE 16,64±0,93 mm, Ea 4,66±0,20, Ees 1,76±0,30, VAC 0,60±0,08, RV SR 18,94±2,10. NTproBNP was 310,9±66,25 at the beginning and 426,45±107,27 so there were no significant dynamics. We found that Ea was significantly inversely associated with NTproBNP dynamics (R=-0,47; P=0,049), and direct correlation with VAC (R=0,648; P=0,004) and RV SR (R=0,489; P=0,024). There were no correlation with Ees.
RV elasticity, measured with several echocardiographic factors as Ea and VAC, as well as RV SR, were significantly associated with NTproBNP dynamics during 6m therapy with sublingual sildenafil.