Prevalence of elevated pulmonary arterial pressures measured by echocardiography in a multicenter study of patients with systemic sclerosis

OBJECTIVE: To estimate the prevalence of elevated pulmonary arterial pressures (PAP) as a correlate for pulmonary arterial hypertension (PAH) in patients with systemic sclerosis (SSc) in rheumatology centers in Canada. METHODS: During the one-year study period (June 2002-May 2003), charts of patients with SSc were reviewed to determine demographics, SSc characteristics, percentage of patients with a PAH diagnosis, and the site criteria for such diagnosis. Subjects with no PAH that had symptoms of dyspnea and/or fatigue were invited to undergo Doppler echocardiography to estimate their systolic PAP (sPAP). RESULTS: A total of 539 patients with SSc (age 56 yrs +/- 13 SD, 84% female, 41% with diffuse SSc, 58% limited SSc, SSc disease duration 9 yrs +/- 7 SD) at 8 rheumatology centers were reviewed. Twenty-three percent of patients were diagnosed with elevated sPAP based on the site diagnosis criteria (i.e., > 30 mm Hg or > 35 mm Hg). From the non-PAH, not recently screened patients that had symptoms of dyspnea or fatigue, a total of 89 patients underwent a Doppler echocardiograph; 40% had sPAP > 35 mm Hg. CONCLUSION: Elevated PAP are common in both limited and diffuse SSc disease, occurring in 21% of limited and 26% of diffuse SSc patients. During the screening most patients had mild PAP elevations that would require further assessments such as right heart catheterization to diagnose PAH where appropriate. A high index of suspicion is important and routine echocardiography in symptomatic patients may allow earlier diagnosis of PAH and intervention. The proportion of SSc patients with mild to moderate elevations of PAP who will develop significant PAH is unknown and longterm studies are needed to address the natural progression.