Insights into Pulmonary Arterial Hypertension in Connective Tissue Diseases

Pulmonary arterial hypertension (PAH) is a severe complication associated with connective tissue diseases (CTDs), which is characterized by a significant influence on the patient's prognosis and mortality. The prevalence of PAH varies depending on the type of CTD. Still, it is highly prevalent in patients with systemic sclerosis (SSc), systemic lupus erythematosus (SLE), mixed connective tissue disease (MCTD), and primary Sjögren's syndrome (pSS). Identifying rheumatic disease-specific risk factors is crucial for early diagnosis and intervention. Risk factors for PAH development include specific sociological factors (related to race, gender, and age), clinical features (particularly severe Raynaud's phenomenon and multiple telangiectasias), cardiological factors (pericarditis and left heart disease), biochemical factors (elevated NT-proBNP and decreased HDL-cholesterol), serological factors (presence of ANA, e.g., anti-U1-RNP or SSA, and antiphospholipid antibodies), and pulmonary factors (interstitial lung disease and decreased DLCO or DLCO/alveolar volume ratio < 70%, FVC/DLCO > 1.6). The analysis of risk factors can be the most useful during the selection of patients at high risk of PAH development. The initial diagnosis of PAH is usually based on transthoracic echocardiography (TTE) and is finally confirmed by right heart catheterization (RHC). Targeted therapies can improve outcomes and include endothelin receptor antagonists, prostacyclin analogs, phosphodiesterase inhibitors, and tailored immunosuppressive treatments. Effective management strategies require a multidisciplinary approach involving rheumatologists, cardiologists, and pulmonologists. The risk stratification and individualized treatment strategies can enhance survival and quality of life in patients with PAH-CTD.