The efficacy of sildenafil therapy in patients with pulmonary hypertension of different etiology: influence on the clinical, functional, hemodynamic status, structure and function of the right and left heart, right ventricular-arterial coupling

Aim: to study the efficacy of sildenafil therapy in pulmonary hypertension of different etiology, its influence on the clinical, functional, hemodynamic status, structure and function of the right and left heart, right ventricular-arterial coupling (RVAC) in pts with idiopathic pulmonary hypertension (IPAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Materials and methods: in the study we included 29 IPAH pts aged 42.8±10.6 yrs, 28 CTEPH pts aged 43.4±10.4 yrs II-IV functional class (FC) (WHO), receiving stable standard therapy (anticoagulants, diuretics, glycosides) and calcium channel blockers for at least 3 months. Sildenafil was started at the dose of 10 mg TID to assess the tolerability for further titration after 1 wk to 20 mg 3 times a day. The treatment duration was 16 wks. At baseline and at wk 16 FC (WHO), 6-minute walking test (6-MWT), transthoracic echocardiography (Echo) and right heart catheterization (RHC) were performed. Results: both groups were comparable in baseline functional parameters: FC, the distance in 6-MWT, Borg index. The analysis of baseline structural and functional cardiac parameters by Echo in IPAH and CTEPH pts revealed pronounced cardiac remodeling as compared to the control group. All pts had criteria precapillary PH by RHC with comparable systolic pulmonary artery pressure (SPAP), mean pulmonary artery pressure (PAPm), cardiac output (CO) and index (CI), pulmonary vascular resistance (PVR) except for diastolic PAP (DPAP), which was higher in IPAH group (38.3±13.7 mm Hg vs 31.5±8.9 mm Hg in CTEPH group (p