The prevalence of undiagnosed pulmonary arterial hypertension in subjects with connective tissue disease at the secondary health care level of community‐based rheumatologists (the UNCOVER study)

Objective Most of the data about the prevalence of pulmonary arterial hypertension (PAH) are from tertiary centers that are biased toward seeing more severe cases; therefore, the true prevalence of PAH among patients with connective tissue disease is unknown. We sought to determine the point prevalence of undiagnosed PAH in community‐based rheumatology practices. Methods The study design was a multicenter, prospective and retrospective survey and analysis of clinical cases in 50 community rheumatology practices. We evaluated a total of 909 patients with either scleroderma (systemic sclerosis [SSc]) or mixed connective tissue disease (MCTD). If a subject had not been diagnosed as having PAH, then a new Doppler echocardiogram was obtained to measure cardiac parameters, including estimated right ventricular systolic pressure (ERVSP), and a full review of medical records was done. Results Of 909 screened patients, 791 were evaluable and completed the study; 669 had not previously been studied for PAH. Of these 669 patients, 89 (13.3%) were found by Doppler echocardiography to have an ERVSP of ≥40 mm Hg. Of these 89 patients, 82 (92.1%) had SSc and 7 (7.9%) had MCTD. The total prevalence of PAH in the survey was 26.7% (211 of 791 patients, including 122 with known PAH and 89 newly diagnosed as having PAH). Doppler echocardiographic data showed 20 of 89 patients (22.5%) with ERVSP of ≥50 mm Hg, 20 of 89 patients (22.5%) with increased RV dimension, and 25 of 89 patients (28.1%) with right atrial enlargement. Patients with ERVSP ≥40 mm Hg had decreased exercise tolerance compared with those with ERVSP