Pulmonary arterial hypertension therapies in patients with obesity hypoventilation syndrome: a case series.

Obesity hypoventilation syndrome (OHS) is caused by complex interactions between multiple pathological processes, including diminished respiratory drive and sleep-related breathing alterations, leading to structural and functional respiratory impairment and ultimately, pulmonary hypertension (PH). Because PH is closely associated with OHS, thoroughly evaluating its etiology is essential, and individualized treatments must be considered. We describe two patients with OHS exhibiting severe PH with pulmonary vascular resistance exceeding 5 Wood units; both were classified as Group 1 PH, i.e., pulmonary arterial hypertension (PAH). Initially admitted to our hospital complaining of dyspnea, both patients commenced PAH therapies in addition to positive airway pressure therapy and diuretics, improving their hemodynamic status, dyspnea, and exercise capacity, and finally enabling their discharge. These findings suggest that PAH can coexist with OHS, and PAH therapies, introduced with careful consideration, may provide substantial benefits for select patients.