Role of pulmonary function tests in screening pulmonary arterial hypertension in scleroderma

Abstract

Pulmonary arterial hypertension (PAH) is a life-threatening complication of scleroderma. Its prevalence is estimated to be between 12 and 29%. The symptoms are usually nonspecific and overlooked in those patients already limited by other complications of their condition. It is recommended to perform noninvasive screening for scleroderma patients for early detection of PAH, which has a significant impact on treatment strategy and clinical outcomes. The aim of this study was to assess the role of certain pulmonary function parameters [forced vital capacity (FVC), diffusion capacity of the lung for carbon monoxide (DLCO), FVC/DLCO] in the early prediction of PAH in scleroderma patients. This prospective study was conducted on 30 scleroderma-diagnosed patients; all patients were subjected to routine laboratory investigations, plain chest radiographic posteroanterior view, computed tomography of the chest, transthoracic echocardiography, spirometry, and DLCO. The echocardiographic results showed pulmonary artery systolic pressure greater than 35 mmHg in eight patients, which led to suspect a possibility of pulmonary hypertension (PH) in those patients. On comparing patients with suspected PH and others, we found significant differences in the values of FVC% and DLCO%, which was significantly lower in patients with suspected PH (P < 0.05), and FVC%/DLCO% was significantly higher in those patients (P < 0.05). The best cutoff value of FVC/DLCO for predicting suspected PH among the studied cases was a value greater than 1.91, with a sensitivity of 87.5% and a specificity of 100%. Assessment of pulmonary functions is an easy and helpful tool in screening pulmonary vasculopathy in scleroderma patients. It helps to suspect patients with early PH, which can be subsequently confirmed with further appropriate tests. Egypt J Broncho 2015 9:287–292