Pulmonary Vascular Reactivity and Prognosis in Patients With Chronic Thromboembolic Pulmonary Hypertension A Pilot Study

Background— Surgical pulmonary endarterectomy is the preferred treatment for chronic thromboembolic pulmonary hypertension. Persistent pulmonary hypertension after pulmonary endarterectomy has been recognized as a major determinant of poor outcome. We tested whether acute vasoreactivity identifies chronic thromboembolic pulmonary hypertension patients prone to develop persistent/recurrent pulmonary hypertension after pulmonary endarterectomy and whether the degree of acute vasoreactivity affects survival or freedom from lung transplantation. Methods and Results— Right-sided heart catheterization at baseline and after inhalation of 40 ppm nitric oxide for 20 minutes was performed in 103 patients (56.3±15.3 years old, 53 women). Reductions in mean pulmonary arterial pressure (ΔmPAP; −8.8±12.6%; P<0.0001) and pulmonary vascular resistance (−16.1±18.1%; P<0.0001) and an increase in mixed venous saturation during inhaled nitric oxide (9.1±11.6%; P<0.0001) were observed. Sixty-two patients underwent pulmonary e...