Abstract 19807: Pre-Superior Cavopulmonary Anastomosis Cardiac Catheterization at Altitude

Abstract

Introduction: Infants with single ventricle physiology typically undergo cardiac catheterization prior to superior cavopulmonary anastomosis (SCPA) to assess operative suitability. Predictors of poor outcome at sea level include elevated central venous pressure (CVP), transpulmonary gradient (TPG), pulmonary vascular resistance (PVR) and pulmonary artery (PA) size. Living at higher altitude has vasoconstrictive effects on the pulmonary vasculature, and a prior study suggested that higher PA pressure may predict worse outcomes. The goal of this study was to determine which elements of the pre-SCPA catheterization were useful in predicting successful Fontan operation at altitude. Methods: A retrospective review revealed 150 patients who underwent pre-SCPA catheterization over a 10-year period. Pre-SCPA catheterization data were abstracted and subjects were grouped by progression to Fontan vs. aborted palliation, heart transplant or death. Statistical analysis included Wilcoxon Rank Sum tests, uni-variable logistic regression and receiver operator characteristic (ROC) curve analysis. Results: Differences between groups at cardiac catheterization are summarized in Table 1. Logistic regression showed that larger PA diameter was protective; left PA: OR: 0.73, 95% CI: 0.6-0.9, p = 0.01; right PA: OR:0.73, 95% CI: 0.6-0.9, p = 0.02. ROC analysis defined thresholds for minimum left PA and right PA diameter of <4mm for poor outcome (area under the curve of 0.68 and 0.67, respectively). Conclusions: Our data suggest that pulmonary arterial size, more so than measured pressure or resistance, influences ability to achieve Fontan palliation at higher altitude. We hypothesize that this may be a feature of differences in pulmonary arterial growth. An alternative approach to evaluating pulmonary arterial morphology during palliation, such as cross-sectional imaging, may help optimize individual patient hemodynamics and provide better predictors of outcome.