Is pulmonary arterial hypertension really a late complication of systemic sclerosis?

Pulmonary arterial hypertension (PAH) is a frequent cause of morbidity and mortality in patients with systemic sclerosis (SSc). PAH is generally considered to be a late complication of limited cutaneous SSc. This study identified and investigated a subset of SSc patients with early-onset PAH.

Clinical and hemodynamic data at the time of diagnosis were collected retrospectively for 78 consecutive patients with PAH associated with SSc. PAH diagnosed within 5 years of the first non-Raynaud phenomenon symptom of SSc was considered to be an early-onset complication. PAH diagnosed > 5 years following SSc diagnosis was considered to be a late complication.

PAH occurred a mean (+/- SD) duration of 6.3 +/- 6.6 years after the diagnosis of SSc (median delay, 4.0 years; 95% CI, 2.88 to 6.0 years). Early-onset PAH was diagnosed in 43 patients (55.1%), and late-onset PAH was diagnosed in 35 patients (44.9%). Patients with early-onset PAH were older at SSc diagnosis than patients with late-onset PAH (mean age, 58.0 +/- 12.5 vs 46.6 +/- 12.9 years, respectively; p = 0.0002). No differences in age at the time of PAH diagnosis, or in SSc subtype (limited vs diffuse; anticentromere vs anti-Scl70 antibodies), were observed between onset subgroups. At diagnosis, early-onset PAH was more severe than late-onset PAH, with a lower cardiac index (2.4 +/- 0.6 vs 2.8 +/- 0.6 L/min/m(2), respectively; p = 0.005) and greater total pulmonary resistance (1,708 +/- 777 vs 1,341 +/- 530 dyne x s x cm(-5)/m(2), respectively; p = 0.02). Mortality at 3 and 5 years was comparable between subgroups.

In contrast to the expected scenario, early-onset PAH occurred in approximately half of SSc patients. Early-onset PAH was as frequent among patients with diffuse SSc as those with limited SSc. Annual screening for PAH should be implemented immediately after SSc diagnosis for all patients.