Scleroderma-associated PAH was associated with significantly less right ventricular hypertrophy with increasing pulmonary vascular resistance compared to idiopathic PAH.
Cross-Sectional (n=53)
Does right ventricular adaptation to load differ between patients with scleroderma-associated PAH and idiopathic PAH?
Patients with SSc-PAH exhibit less adaptive right ventricular hypertrophy in response to increased pulmonary vascular resistance compared to those with IPAH, potentially explaining their poorer clinical outcomes.
Patients with scleroderma (SSc)-associated pulmonary arterial hypertension (PAH) have worse survival than patients with idiopathic PAH (IPAH). We hypothesized that the right ventricle (RV) adapts differently in SSc-PAH versus IPAH. We used cardiac magnetic resonance imaging (cMRI) and hemodynamic characteristics to assess the relationship between RV morphology and RV load in patients with SSc-PAH and IPAH. In 53 patients with PAH (35 with SSc-PAH and 18 with IPAH) diagnosed by right heart catheterization (RHC), we examined cMRIs obtained within 48 hours of RHC and compared RV morphology between groups. Regression analysis was used to assess the association between diagnosis (IPAH vs. SSc-PAH) and RV measurements after adjusting for age, sex, race, body mass index (BMI), left ventricular (LV) mass, and RV load. There were no significant differences in unadjusted comparisons of cMRI measurements between the two groups. Univariable regression showed RV mass index (RVMI) was linearly associated with measures of RV load in both the overall cohort and within each group. Multivariable linear regression models revealed a significant interaction between disease type and RVMI adjusting for pulmonary vascular resistance (PVR), age, sex, race, BMI, and LV mass. This model showed a decreased slope in the relationship between RVMI and PVR in the SSc-PAH group compared with the IPAH group. RVMI varies linearly with measures of RV load. After adjusting for multiple potential confounders, patients with SSc-PAH demonstrated significantly less RV hypertrophy with increasing PVR than patients with IPAH. This difference in adaptive hypertrophy may in part explain previously observed decreased contractility and poorer survival in SSc-PAH.
Kelemen et al. (2015) conducted a cross-sectional in Pulmonary arterial hypertension (n=53). Scleroderma-associated pulmonary arterial hypertension (SSc-PAH) vs. Idiopathic pulmonary arterial hypertension (IPAH) was evaluated on Relationship between right ventricular mass index (RVMI) and pulmonary vascular resistance (PVR). Scleroderma-associated PAH was associated with significantly less right ventricular hypertrophy with increasing pulmonary vascular resistance compared to idiopathic PAH.