Epidemiology and disease characteristics of systemic sclerosis-related pulmonary arterial hypertension: results from a real-life screening programme

Abstract

Background: Pulmonary arterial hypertension (PAH) is the leading cause of death in systemic sclerosis (SSc). Annual screening with echocardiogram (ECHO) is recommended. We present the methodological aspects of a PAH screening programme in a large Australian SSc cohort, the epidemiology of SSc-PAH in this cohort, and an evaluation of factors influencing physician adherence to PAH screening guidelines.

Methods: Patient characteristics and results of PAH screening were determined in all patients enrolled in a SSc longitudinal cohort study. Adherence to PAH screening guidelines was assessed by a survey of Australian rheumatologists. Summary statistics, chi-square tests, univariate and multivariable logistic regression were used to determine the associations of risk factors with PAH.

Results: Among 1636 patients with SSc, 194 (11.9%) had PAH proven by right-heart catheter. Of these, 160 were detected by screening. The annual incidence of PAH was 1.4%. Patients with PAH diagnosed on subsequent screens, compared with patients in whom PAH was diagnosed on first screen, were more likely to have diffuse SSc (p = 0.03), be in a better World Health Organisation (WHO) Functional Class at PAH diagnosis (p = 0.01) and have less advanced PAH evidenced by higher mean six-minute walk distance (p = 0.03), lower mean pulmonary arterial pressure (p = 0.009), lower mean pulmonary vascular resistance (p = 0.006) and fewer non-trivial pericardial effusions (p = 0.03). Adherence to annual PAH screening using an ECHO-based algorithm was poor among Australian rheumatologists, with less than half screening their patients with SSc of more than ten years disease duration.

Conclusion: PAH is a common complication of SSc. Physician adherence to PAH screening recommendations remains poor. Identifying modifiable barriers to screening may improve adherence and ultimately patient outcomes.

Keywords: Pulmonary arterial hypertension; Scleroderma; Screening algorithm; Systemic sclerosis.

Fig. 1

Australian Scleroderma Cohort Study algorithm for screening for pulmonary hypertension. ANA antinuclear antibody, ENA extractable nuclear antibody, CXR chest radiograph, ECG electrocardiogram, TTE transthoracic echocardiogram, PFT pulmonary function test, 6MWT six-minute walk test, PAH pulmonary arterial hypertension, sPAP systolic pulmonary arterial pressure, DLCO diffusing capacity of the lung for carbon monoxide corrected for haemoglobin, RHC right-heart catheterization, HRCT high-resolution chest computed tomography, V/Q ventilation perfusion, CTPA computed tomography pulmonary angiography

Fig. 2

Survival in systemic sclerosis (SSc) with pulmonary arterial hypertension (PAH) according to the screening visit when the diagnosis was made (first vs subsequent)