Treatment with epoprostenol reverts nitric oxide non-responsiveness in patients with primary pulmonary hypertension

Objective-To assess whether long term treatment with epoprostenol might res tore primary non-responsiveness to nitric oxide (NO) in patients with prima ry pulmonary hypertension. Methods-Seven patients with primary pulmonary hypertension receiving intrav enous epoprostenol continuously because of failure of NO to influence pulmo nary haemodynamics during initial testing were followed over a period of 13 -29 months. Afterwards, acute Vascular reactivity towards NO was rested aga in during right heart catheterisation. Results-Administration of NO after continuous epoprostenol treatment for a mean period of 18 months improved arterial oxygen saturation (p < 0.01) and cardiac index (p < 0.05), and decreased mean pulmonary artery pressure (p < 0.01) and total pulmonary vascular resistance (p < 0.01) in patients prev iously unresponsive to NO. Conclusions-Long term treatment with epoprostenol reverts initial refractor iness to NO in patients with primary pulmonary hypertension. Thus the addit ion of NO to epoprostenol treatment might cause further improvement in the course of the disease.