Pulmonary hypertension phenotypes in patients with systemic sclerosis

Abstract

Pulmonary hypertension (PH) commonly affects patients with systemic sclerosis (SSc) and is associated with significant morbidity and increased mortality. PH is a heterogenous condition and several different forms can be associated with SSc, including pulmonary arterial hypertension (PAH) resulting from a pulmonary arterial vasculopathy, PH due to left heart disease and PH due to interstitial lung disease. The incidence of pulmonary veno-occlusive disease is also increased. Accurate and early diagnosis to allow optimal treatment is, therefore, essential. Recent changes to diagnostic haemodynamic criteria at the 6th World Symposium on Pulmonary Hypertension have resulted in therapeutic uncertainty regarding patients with borderline pulmonary haemodynamics. Furthermore, the optimal pulmonary vascular resistance threshold for diagnosing PAH and the role of exercise in identifying early disease require further elucidation. In this article we review the epidemiology, diagnosis, outcomes and treatment of the spectrum of pulmonary vascular phenotypes associated with SSc.

FIGURE 1

Potential pulmonary hypertension (PH) classification groups associated with systemic sclerosis. Patients may develop a pulmonary arterial vasculopathy (group 1, pulmonary arterial hypertension), may develop PH due to left heart disease (group 2) or PH due to lung disease (group 3; most commonly interstitial lung disease, although the incidence of combined fibrosis and emphysema is also increased). The incidence of pulmonary veno-occlusive disease (group 1′) also appears to be increased in systemic sclerosis. Chronic thromboembolic PH (group 4) should be excluded while patients with a previous scleroderma renal crisis who progress to end-stage chronic kidney disease may develop group 5 disease. Reproduced and modified from [4] with permission from the publisher.