Identifying early pulmonary arterial hypertension in patients with systemic sclerosis

Pulmonary arterial hypertension (PAH) is a life-shortening complication of systemic sclerosis (SSc) with a life-time prevalence of approximately 10% [1, 2]. It is currently defined by the presence of a mean pulmonary arterial pressure (mPAP) ≥25 mmHg with a pulmonary arterial wedge pressure (PAWP) ≤15 mmHg and a pulmonary vascular resistance (PVR) >3 WU, in the absence of significant lung disease or chronic thromboembolic disease. Other forms of pulmonary hypertension (PH) may also quite commonly exist in SSc patients, including PH due to left heart disease or lung disease. It is widely agreed that identifying patients with SSc who also have PAH (SSc-PAH) earlier in their disease process is likely a good idea with the presumption that earlier diagnosis leads to earlier treatment, which hopefully leads to better outcomes. Certainly, previous data have demonstrated superior survival in patients with SSc-PAH identified by screening when compared with patients presenting due to symptoms [3]. Over the past few years several groups have investigated the optimal way of screening SSc patients for the presence of PAH, most notably the DETECT investigators [4]. The DETECT study demonstrated that in a population of SSc patients enriched for the likely presence of PAH (by including patients only with a diffusion coefficient for carbon monoxide, DLCO,