Is Right Ventricular Remodeling in Pulmonary Hypertension Dependent on Etiology? An Echocardiographic Study

Survival in patients (pts) with pulmonary hypertension (PH) differs between subgroups at similar levels of pressure overload. We set to analyze right ventricular (RV) morphology and function in different types of PH using conventional and deformation imaging echocardiography.

Thirty-four pts with PH: 12 pts with idiopathic pulmonary arterial hypertension (IPAH, 42.2 ± 13 years), 11 pts with chronic thromboembolic PH (CTEPH, 50.8 ± 12 years), 11 pts with Eisenmenger syndrome [ES 41.2 ± 15 years, 4 with atrial septal defect (ASD) and 7 with ventricular septal defect (VSD)], and 13 age-matched healthy individuals (38.1 ± 15 years) were evaluated. The following echocardiographic parameters were measured: echo-derived systolic pulmonary pressure (sPAPecho), RV end-diastolic diameter (RVEDD), RV wall thickness (RVWT), TAPSE, RV fractional area change (RVFAC), Tei index, peak systolic velocity of the tricuspid ring (S't), and speckle tracking-derived RV free wall strain. Furthermore, right heart catheterization (RHC) was performed in pts with PH and mean, and systolic pulmonary artery pressure (mPAPcath, sPAPcath), cardiac output (CO), cardiac index (COi), and pulmonary vascular resistance (PVR) were noted.

The levels of mPAPcath and sPAPcath were similar between pts with PH (pANOVA = NS). Patients with ES had higher COi compared to other groups (2.94 ± 0.79, 2.28 ± 0.69, and 1.74 ± 0.46 L/min/m(2) for pts with ES, IPAH, and CTEPH respectively, pANOVA = 0.004, P post hoc ES versus all other groups < 0.05). TAPSE, Tei index, and S't were similar between groups and impaired versus controls (pANOVA < 0.001, P post hoc between groups of patients = NS). Patients with ES had better RVFAC (41.1 ± 9, 30.5 ± 10.8, 23.2 ± 9.8%) and RV free wall strain (-20.6 ± 3.5, -16.3 ± 7.5, -10.8 ± 5%), as well as an increased thickness of the RV free wall compared to other groups of patients (9.2 ± 1.5, 7.2 ± 1 and 7.2 ± 1.6 mm for pts with ES, IPAH and CTEPH, respectively) (pANOVA<0.001, P post hoc <0.05 ES versus all other groups). RVFAC and RV free wall strain significantly correlated with COi (r = 0.53, P = 0.006 and r = -0.77, P < 0.001, respectively).

Patients with ES have a more hypertrophied RV free wall, better RV performance as assessed by RVFAC and RV free wall strain and increased COi compared to other types of PH. Furthermore, RV performance appears to be less dependent on the level of pressure overload. These findings could contribute to the better survival profile of patients with ES.