Case reports have suggested that bariatric surgery improves pulmonary hypertension. We performed a retrospective, case–control study to evaluate the safety and efficacy of bariatric surgery in obese patients with severe pulmonary hypertension. Morbidly obese patients followed in a specialty pulmonary hypertension clinic who underwent laparoscopic gastric bypass or sleeve gastrectomy between 2008 and 2013 (n = 10) were compared to a BMI-matched cohort managed with maximal medical therapy (n = 10). Patients with advanced malignancy, prior heart/lung transplantation, and pulmonary hypertension from thromboembolism were excluded. Primary outcomes assessed were changes in use of pulmonary vasodilatory and diuretic medications, need for home oxygen therapy, and mean pulmonary arterial pressures. Secondary outcomes measured were excess body weight loss, perioperative mortality and morbidity, and hospital length of stay. More patients who underwent bariatric surgery experienced improvements in pulmonary arterial pressures (75 vs. 0 %, p = 0.02), reduction in or discontinuation of pulmonary vasodilatory therapy (67 vs. 0 %, p = 0.01), and decreased diuretic requirements (86 vs. 13 %, p = 0.01) than the control cohort. Seventy-five percent of patients previously on home oxygen discontinued therapy after surgery, while oxygen requirements increased in 50 % of the control cohort. Excess body weight loss was greater in the surgical group (EWL 68 vs. 19 %, p
