Pulmonary Hypertension in Connective Tissue Disease is Associated with the New York Heart Association Functional Class and Forced Vital Capacity, But Not with Interstitial Lung Disease

Abstract

OBJECTIVE: Pulmonary hypertension (PH) develops frequently in connective tissue diseases (CTD) and is an important prognostic factor. The aim of this study was to assess the prevalence of PH in patients with CTD by non-invasive echocardiography and analyze the potential biomarkers for helping to detect PH. METHODS: All Korean patients with CTD who had dyspnea on exertion or interstitial lung disease (ILD) were screened for PH with echocardiography and clinical data were collected from four hospitals. RESULTS: Among 196 patients with CTD, 108 (55.1%) had ILD and 21 had PH defined as >40 mmHg. Of the 21 patients with PH, 10, 4, and 3 patients had systemic sclerosis, systemic lupus erythematosus, and mixed connective tissue disease, respectively. There was no difference in the incidence of PH according to the presence of ILD: 12 patients (11.1%) with ILD had PH and 9 patients (10.2%) without ILD had PH. The results of the pulmonary function test, total cholesterol, red cell volume distribution width, alkaline phosphatase, and the New York Heart Association (NYHA) functional class III or IV differed significantly according to the presence of PH. In multiple regression analysis, NYHA functional class III or IV (odd ratio [OR]=7.3, p=0.009) and forced vital capacity (OR=0.97, p=0.043) were independent predictive factors of PH. CONCLUSION: PH is not associated with the presence of ILD in Korean patients with CTD. On the other hand, NYHA functional class III or IV and decreased forced vital capacity indicate the presence of PH in connective tissue disease.