Outcome measures in pulmonary arterial hypertension associated with systemic sclerosis

SSc is complicated in approximately 10% of the patients by pulmonary arterial hypertension (PAH), a rare dyspnoea-fatigue syndrome caused by an increase in pulmonary vascular resistance. The prognosis of SSc-PAH is particularly poor, with estimated survival rates of approximately 50% at 2 yrs without pulmonary circulation-targeted therapies. Prostacyclins, endothelin receptor antagonists and phosphodiesterase-5 inhibitors have been shown to be efficacious in PAH, with persistent long-term benefit and approximate doubling of survival rate, and these encouraging results appear transposable to the SSc-PAH subcategory. However, PAH as well as SSc-PAH remain incurable, with insufficient functional improvement in many patients. More progress is needed, and this will require more effective drugs and adapted outcome measures.