2013 ACR/EULAR systemic sclerosis classification criteria in patients with associated pulmonary arterial hypertension

To analyze the performance of the 1980 ACR and new 2013 ACR/EULAR criteria for systemic sclerosis (SSc) in cutaneous SSc (lcSSc) patients, especially those affected by lcSSc and pulmonary arterial hypertension (PAH).

All patients with a clinical lcSSc diagnosis from a prospective observational SSc cohort were included. Sociodemographic and disease-related variables were collected, and PAH confirmed by right heart catheterization (RHC). Performance of the 2013 and 1980 SSc criteria was analyzed in terms of clinical diagnosis. Descriptive and between-group analyses were performed as to the fulfillment of criterion sets, including comparison of survival.

Overall, 321 patients were included, 63% of whom fulfilled the 1980 ACR and 93% the 2013 ACR/EULAR criteria. Agreement between both criteria sets proved poor (κ = 0.23). LcSSC patients fulfilling both criterion sets were significantly younger at diagnosis, whilst presenting organ involvement, calcinosis, fingertip digital ulcers, and pitting scars more frequently than those who met the 2013 criteria only. Patients who fulfilled the 2013 but not the 1980 criteria presented a higher degree of ACA positivity and PAH. Nearly 12% of patients developed PAH. Patients who did not meet the 1980 criteria were affected by a milder disease from but demonstrated higher pulmonary vascular resistance and lower cardiac index than those fulfilling both criterion sets. Whereas patients with PAH met the 2013 criteria, only 47% fulfilled the 1980 criteria. Regardless of criterion set fulfillment, high mortality was observed in PAH patients, with no significant between-patient difference based on criterion set.

The new 2013 ARC/EULAR criteria prove more accurate than the former 1980 ACR criteria in identifying and differentiating patients with lcSSc, especially those with associated PAH. Since PAH exhibits a better prognosis if treated early, all SSc patients should undergo PAH screening.