Prevalence of pulmonary arterial hypertension in an Australian scleroderma population: screening allows for earlier diagnosis
Background: We sought to determine the prevalence of pulmonary complications and especially pulmonary arterial hypertension (PAH) in an Australian scleroderma population.
Methods: Between July 2005 and June 2007, physicians in Western Australia were asked to refer patients with scleroderma specifically for pulmonary hypertension screening. All patients were assessed for PAH and other respiratory conditions using echocardiography, lung function testing and clinical assessments. Right heart catheterization was carried out in patients with evidence of increased right ventricular systolic pressure.
Results: Of the 184 patients analysed, 44 had possible PAH on echocardiography. Right heart catheterization confirmed the diagnosis in 24 (13%). Diffuse interstitial lung disease was found in 32 patients representing a point prevalence of 17.4%. The severity of PAH at diagnosis varied according to whether the patients were referred for screening (group A) or for diagnostic (group B) purposes. The 6-min-walk test distance and median pulmonary vascular resistance were significantly worse in group B versus group A (324 vs 402 m; P= 0.02 and 884 dynes/s per cm−5 vs 486 dynes/s per cm−5; P < 0.01, respectively).
Conclusion: Screening may result in earlier diagnosis of PAH with, in general more mild disease. This is important, given that early treatment for PAH while patients are less symptomatic is associated with improved exercise tolerance and pulmonary haemodynamics: indices indicative of disease progression and clinical worsening.