Idiopathic pulmonary arterial hypertension (IPAH) and pulmonary arterial hypertension related to scleroderma (PAH-SSc) are characterized by progressive increases in pulmonary vascular resistance with resultant right ventricular dysfunction, failure, and eventual death. Despite similar hemodynamics, patients with PAH-SSc have poorer response to therapy and worse outcomes. Differences in echocardiographic measures of right ventricular function and morphology may have important prognostic significance in this patient population.
Comprehensive evaluations were performed in consecutive patients with IPAH or PAH-SSc including right heart catheterization and transthoracic echocardiograms. The echocardiograms were interpreted with special attention to right sided chamber function and morphology including right atrial and ventricular areas, eccentricity index, and tricuspid annular plane systolic excursion (TAPSE). The echocardiograms were interpreted without knowledge of the right heart catheterization results or the patient’s diagnosis. The patients were then prospectively followed to determine long-term survival.
Thirty-three patients (15 IPAH and 18 PAH-SSc) were included in the study. Patients with PAH-SSc were older (60.5 ± 12.7 vs. 44.5 ± 12.4, P-value < 0.001). There was no difference between right atrial pressure and cardiac index between groups; however, patients with PAH-SSc had lower mean pulmonary artery pressures (45.2 ± 9.9 vs. 54.5 ± 14.5, P-value 0.036). There was a trend towards increased right atrial size and right ventricular area, and a decreased eccentricity index for the PAH-SSc group. Pericardial effusions were more likely in the PAH-SSc patients then the patients with IPAH (50% vs. 7%, Chi-squared=0.007). Right ventricular function as measured by TAPSE was significantly reduced in the PAH-SSc group (1.7 ± 0.5 vs 2.1 ± 0.7, P-value 0.042). One-year outcomes are pending.
Patients with PAH-SSc have reduced right ventricular function and are more likely to have a pericardial effusion present despite having milder pulmonary hypertension. These results suggest that the right ventricle in patients with PAH-SSc is less adaptable to elevation in pulmonary artery pressure.
Echocardiographic measurements of right ventricular function may have prognostic significance for long-term survival.
Micah Fisher, None.