Pulmonary hypertension in connective tissue diseases: an update

Pulmonary hypertension (PH) is a relatively commoner complication of systemic sclerosis (SSc) with estimated prevalence ranging between 8% and 12% as compared to much lower figures in other connective tissue diseases (CTD). It is a major cause of morbidity and mortality in CTDs. PH is classified into five major groups. CTD-associated PH belongs to group 1 PH, also known as pulmonary arterial hypertension (PAH). Around 30% of scleroderma-related deaths are due to PAH. Underlying pathogenesis is related to pulmonary vasculopathy involving small vessels. The Evidence-based Detection of Pulmonary Arterial Hypertension in Systemic sclerosis (DETECT) algorithm outperforms the current European Society of Cardiology/European Respiratory Society guidelines as a screening tool in SSc-PAH; it can, therefore, suggest when to refer a patient for right heart catheterization. CTD-PAH patients constitute at least 20% of patients included in all major trials of PH-specific therapy and the results are comparable to those of idiopathic PAH. The role of anticoagulation in CTD-PAH is associated with a high risk-benefit ratio with the caveat of its potential role in those with severe disease. There appears to be no role of immunosuppression in scleroderma-PAH; however, immunosuppressive agents, namely the combination of glucocorticoids and pulse cyclophosphamide / possibly mycophenolate, may result in clinical improvement in a subset of patients with systemic lupus erythematosus and mixed connective tissue disease-related PAH.