Abstract 16375: Low Nasal Nitric Oxide as a Prognosticator of Failing Single Ventricle Physiology in Congenital Heart Disease Patients?
Introduction: Pulmonary arterial hypertension (PAH) is a major complication in patients with congenital heart disease (CHD). The mechanism of PAH in CHD is multi-factorial and includes increased pulmonary blood flow/pressure, shear stress to pulmonary arteries, and vasoconstriction, proliferation, and thrombosis to the pulmonary vascular bed. PAH patients are treated with medications to increase nitric oxide (NO) levels, as reduction of endothelial-derived NO is thought to contribute to PAH pathogenesis. Interestingly, we recently showed some CHD patients can have very low nasal nitric oxide (nNO), prompting us to investigate the hypothesis that CHD patients with low nNO may have increased risk for PAH.
Methods: Retrospective chart review of cardiac catheterization was performed and pulmonary arterial hemodynamic data were analyzed in 85 CHD patients. Nasal NO measurements were obtained, and patients with low nNO were identified using nNO cutoff values used for diagnosis of primary ciliary dyskinesia (PCD), a sinopulmonary disease associated with very low nNO.
Results: No significant correlation was found between low nNO and mean pulmonary artery pressures, indexed PVR, or pulmonary blood flow in CHD patients. However, CHD patients with failing Fontan/bidirectional Glenn (BDG) circulations and functional BDG had significantly lower nNO as compared to CHD patients with functioning Fontan circulations (p < 0.0001). Furthermore, CHD patients with single ventricle physiology were 14 times more likely to fail if they have extremely low nNO levels below the PCD cut off values (OR 14.8, p = 0.006). In several patients, nNO measurements before and after heart transplantation showed persistence of the nNO deficiency after transplantation, suggesting an intrinsic defect in nNO production unrelated to post-surgical alterations in pulmonary blood flow.
Conclusions: In CHD patients, there was no correlation between low nNO and PAH, but instead, a highly significant correlation was observed between low nNO and failing Fontan/BDG circulations. These novel findings suggest further studies are warranted to investigate whether low nNO may be a prognosticator of poor outcome in Fontan subjects and thus may guide clinical care of such high-risk CHD patients.
Author Disclosures: C. Yau: None. M. Zahid: None. O. Khalifa: None. W. Devine: None. L. Leatherbury: None. P. Wearden: None. C. Lo: None.
- © 2014 by American Heart Association, Inc.