Clinical characteristics and prognosis of connective tissue disease-associated pulmonary arterial hypertension

Abstract Background Pulmonary arterial hypertension (PAH) is a series of clinicopathological syndromes associated with elevated pulmonary arterial pressure caused by various reasons, and is also the most serious complication of connective tissue disease (CTD). This study aims to evaluate the clinical features and prognostic factors of CTD associated PAH (CTD-PAH) patients in the Chinese Han population, and provide a reference basis for improving their prognosis. Methods A total of 392 individuals with CTD between January 2017 and August 2021 were included in this study. They were divided into two main groups: CTD-PAH and CTD-non-PAH. The independent sample t-test and Mann-Whitney U test were used to compare clinical and laboratory findings. Receiver operating characteristic (ROC) curves were converted into binary variables to determine the critical value. A Kaplan-Meier survival analysis was used to compare the survival rates of the two groups. And an analysis of death risk factors was conducted using Cox regression. Results In this study, SLE was the most common underlying disease among Chinese Han patients with CTD-PAH (51.56%). The level of anti-U1-RNP antibodies was significantly higher in the CTD-PAH group as compared to the CTD-non-PAH group (P = 0.001), whereas the levels of anti-SCL-70 antibodies were lower (P < 0.001). CTD patients with higher anti-U1-RNP antibodies levels were at high risk for PAH (P = 0.021), whereas higher levels of anti-U1-RNP have also been linked to decreased mortality in CTD-PAH (P < 0.001). In addition, the anti-SCL-70 antibody was an independent protective factor for CTD-PAH (P = 0.029). The poor prognosis of CTD-PAH was associated with high RDW (P = 0.010), NLR (P < 0.001), CAR (P = 0.001) and pulmonary infection (P = 0.008). Conclusion Patients with CTD who have higher levels of anti-U1-RNP antibodies are at high risk for PAH, whereas higher levels of anti-U1-RNP antibodies have also been linked to decreased mortality. An increase in the anti-SCL-70 antibody levels is an independent protective factor against CTD-PAH. High CAR, NLR, RDW and pulmonary infection are also significant determinants of total mortality in patients with CTD-PAH.