Differences in Right Ventricular Functional Changes during Treatment between Systemic Sclerosis-associated Pulmonary Arterial Hypertension and Idiopathic Pulmonary Arterial Hypertension

Abstract

Rationale: Patients with systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) continue to have an unacceptably high mortality rate despite the progress achieved with pulmonary arterial vasodilator therapies.

Objectives: We sought to determine whether SSc-PAH is a clinically distinct pulmonary vascular disease phenotype when compared with idiopathic pulmonary arterial hypertension (IPAH) on the basis of progression of echocardiographic right ventricular (RV) dysfunction.

Methods: Retrospective analysis of echocardiographic data in 13 patients with SSc-PAH and 11 patients with IPAH was used to delineate the progression of RV dysfunction during single or combination pulmonary arterial vasodilator therapy. All patients had right heart catheterization-confirmed pulmonary arterial hypertension as well as complete baseline (at the time of diagnosis) and follow-up (most recent) echocardiograms. We excluded patients with significant scleroderma-associated interstitial lung disease. Adjusting for time of follow-up and disease duration, we performed mixed model regression analyses comparing the changes between the two groups for different echocardiographic variables: tricuspid annular plane systolic excursion, tricuspid regurgitation jet velocity, right atrial area, and RV diameter.

Results: The mean ages for the SSc-PAH and IPAH groups were 60.8 and 48.2 years, respectively. The mean follow-up periods for the two groups were 3.8 and 1.95 years, respectively. Tricuspid annular plane systolic excursion did not improve in patients with SSc-PAH, whereas it increased in the patients with IPAH (-0.38 mm, P = 0.87; vs. +5.6 mm, P = 0.02). The other echocardiographic variables showed a trend toward worsening in the SSc-PAH group and improvement in the IPAH group.

Conclusions: Our results indicate that, in patients with SSc-PAH, echocardiographic RV function does not improve over time compared with that of patients with IPAH, despite institution of pulmonary artery vasodilator therapies.

Keywords: disease progression; idiopathic pulmonary arterial hypertension; pulmonary arterial hypertension; right ventricle; systemic sclerosis–associated pulmonary arterial hypertension.

Figures

Figure 1.

Disease duration and follow-up time. Right heart catheterization (RHC) was used to diagnose pulmonary arterial hypertension. Baseline ECHO = first available echocardiogram; follow-up ECHO = most recent echocardiogram.

Figure 2.

Consolidated Standards of Reporting Trials (CONSORT) diagram showing the selection of patients with systemic sclerosis–associated pulmonary arterial hypertension (SSc-PAH) and patients with idiopathic pulmonary arterial hypertension (IPAH) for this study. PAH = pulmonary arterial hypertension; PH = pulmonary hypertension; UCTD = undifferentiated connective tissue disease; WHO = World Health Organization.

Figure 3.

Change in mean tricuspid annular plane systolic excursion (TAPSE) from baseline to follow-up. The error bars represent the SEM. IPAH = idiopathic pulmonary arterial hypertension; SSc-PAH = systemic sclerosis-associated pulmonary arterial hypertension.