Pulmonary arterial hypertension related to connective tissue disease: a review

PAH associated with connective tissue diseases is associated with significant functional impairment and morbidity, and carries with it a poor prognosis. The mortality is as high as 10% to 15% in the first year after diagnosis; making it a devastating disease. The availability of ever-increasing numbers of treatment options in the recent era have improved survival in this patient population and have made early and accurate diagnosis a more important goal. According to the Registry to Evaluate Early and Long-Term Pulmonary Arterial Hypertension Disease Management (REVEAL), 1-year, 3-year, 5-year, and 7-year survival rates from time of diagnostic right-sided heart catheterization in patients with PAH were found to be 85%, 68%, 57%, and 49%, respectively, which is a considerable improvement since the National Institutes of Health registry 2 decades previously. In a study by Condliffe and colleagues, survival rates in patients with SSC-associated PAH have improved to 78%at 1 year and 47% at 3 years. Patients with SLE-related PAH have a much higher survival rate of up to 75% at 3 years. Proper screening, early diagnosis, and early treatment can have a significant impact in reducing morbidity and mortality. A small study to assess outcomes in patients with asymptomatic CTD found to have exercise induced PAH suggest that bosentan may be safe and effective in improving the hemodynamics and outcomes in these patients. This study included only 10 patients, and additional randomized trials with larger numbers of subjects are needed to affirm this hypothesis. Studies are under way to find additional therapeutic modalities in the form of PDGF receptor blockers, VEGF blockers, tyrosine kinase inhibitors, endothelial dysfunction inhibitors, multikinase inhibitor of Raf-1, serotonin receptor antagonists,and rho kinase inhibitors. Despite these, clinical suspicion, early diagnosis, early