Vasoreactivity to Inhaled Nitric Oxide with Oxygen Predicts Long-Term Survival in Pulmonary Arterial Hypertension

PVRI Member Authors: Aaron Waxman

Abstract

Pulmonary vasodilator testing is currently used to guide management of patients with pulmonary arterial hypertension (PAH). However, the utility of the pulmonary vascular response to inhaled nitric oxide (NO) and oxygen in predicting survival has not been established. Eighty patients with WHO Group I PAH underwent vasodilator testing with inhaled NO (80 ppm with 90% O2 for 10 minutes) at the time of diagnosis. Changes in right atrial (RA) pressure, mean pulmonary artery pressure (mPAP), pulmonary capillary wedge pressure, Fick cardiac output, and pulmonary vascular resistance (PVR) were tested for associations to long-term survival (median follow-up 2.4 years). Five-year survival was 56%. Baseline PVR (mean±SD 850±580 dyne-sec/cm5) and mPAP (49±14 mmHg) did not predict survival, whereas the change in either PVR or mPAP while breathing NO and O2 was predictive. Patients with a ≥30% reduction in PVR with inhaled NO and O2 had a 53% relative reduction in mortality (Cox hazard ratio 0.47, 95% confidence interval (CI) 0.23–0.99, P=0.047), and those with a ≥12% reduction in mPAP with inhaled NO and O2 had a 55% relative reduction in mortality (hazard ratio 0.45, 95% CI 0.22–0.96, P=0.038). The same vasoreactive thresholds predicted survival in the subset of patients who never were treated with calcium channel antagonists (n=66). Multivariate analysis showed that decreases in PVR and mPAP with inhaled NO and O2 were independent predictors of survival. Reduction in PVR or mPAP during short-term administration of inhaled NO and O2 predicts survival in PAH patients.

Read the full article online

Topics

Nitric Oxide and Nitric Oxide Synthase
Survival
Vasoreactivity: Vasoconstriction and Vasodilatation

Authors

Rajeev Malhotra, Dean Hess, Gregory D. Lewis, Kenneth D. Bloch, Aaron B. Waxman, Marc J. Semigran

Published in:

Pulmonary Circulation Vol 1: No 2 cover image

June 2011

Pulmonary Circulation Vol 1: No 2

View this journal

Our research platform is the world.

Through worldwide collaboration, we can begin to answer the question of a global disease.

Join the PVRI
standard-example-image.jpg