While no prospective clinical trials of anti-TNF therapy have been performed in PH and there is concern due to a study in which infliximab caused worsening heart failure (46), there are case reports of patients with scleroderma and rheumatoid arthritis who experienced worsening of PAH after cessation of anti-TNF therapy (47, 48) suggesting potential benefit particularly in the setting of CTD-PAH. This evidence concerns the gene TNF and heart failure.