Factors influncinig 6 MWD in sclerodermia patients with pulmonary symptoms

Abstract

Introduction: Pulmonary involvement is the most common cause of death in Systemic sclerosis (SSc). The six-minute walk test (6MWT) is a simple and non-invasive test used to assess cardiopulmonary performance. The aim of this study was to evaluate the performance of 6MWT in predicting PAH and interstitial lung disease in patients with SSc and cardiopulmonary symptoms. Methods: Patients with SSc who had cardiopulmonary symptoms including dyspnea, cough, chest pain and syncope were enrolled in this study. Patients underwent 6MWT, high-resolution computed tomography (HRCT), spirometry, body plethysmography and single breath carbon monoxide diffusion measurement in respiratory lab. Based on the extent of the lung parenchyma involvement in HRCT, patients were divided into two groups of <20% and ≥20% lung parenchyma involvement. Pulmonary arterial pressure (PAP) was measured by echocardiography. Results: Sixty-three patients with SSc and cardiopulmonary symptoms underwent 6MWT. There were no significant differences in mean 6MWD between the SSc subgroups including patients with diffuse SSc compared with limited disease, patients with no parenchymal involvement compared with patients with parenchymal involvement < 20% and ≥ 20% in HRCT, and patients with PAP ≥ 25 mmHg compared with patents with PAP < 25 mmHg. We analyzed relationship between 6MWD and age, PAP, forced expiratory volume, forced vital capacity and diffusing capacity of the lungs for carbon monoxide. No significant relationship was found between them.