The Сlinical Impact of Pulmonary Artery Distensibility Index in Patients With Pulmonary Hypertension

Objective. Vascular remodeling in patients with pulmonary artery hypertension (PAH) may be assessed by measurement of contrast magnetic-resonance imaging (CMRI) derived pulmonary artery distensibility (PAD) index. The objective of our study was to investigate whether PAD index could be used as a marker for the evaluation of PAH severity. Design and methods. Forty four patients with PAH (mean age — 42,8 ± 14,5 years, males:females = 11:33) were enrolled: 29 patients with idiopathic pulmonary arterial hypertension, 4 subjects with corrected congenital heart disease, 3 subjects with scleroderma PAH and 8 patients with inoperable chronic thromboembolic pulmonary hypertension. All patients underwent 6-minute walk test, right heart catheterization (RHC), heart ultrasound (ECHO), CMRI, cardiopulmonary exercise testing, and serum N-terminal-pro-brain natriuretic peptide (NT-proBNP) level was defined. Results. PAD index was decreased in PAH patients 11,9 % (9,3-19,7). Patients with decreased PAD index < 20 % had higher NT-proBNP level, lower tricuspid annular systolic velocity and right ventricle/left ventricle ratio by ECHO. Patients with PAD index < 20 % had higher pulmonary artery systolic blood pressure (96,5 ± 22,4 versus 77,9 ± 19,4 mmHg; p < 0,05), and reduced cardiac output which were determined by RHC (3,98 ± 1,1 versus 4,95 ± 1,21 l/min; p < 0,05). Decreased VO2peak was found in patients with PAD index < 20 % (14,8 versus 18,8 ml/min/kg; p = 0,05). Conclusions. PA distensibility index may be used for noninvasive assessment of PAH severity and progression.