Elevated Pulmonary Artery Pressure, Not Pulmonary Vascular Resistance, is an Independent Predictor of Morbidity Following Bidirectional Cavopulmonary Connection (original) (raw)

Background: Successful single ventricle palliation relies on the pulmonary vasculature accommodating non-pulsatile venous return from the body. Mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance (PVR) are two interdependent measures of pulmonary vasculature that can impact pulmonary blood flow following bidirectional cavopulmonary connection (BCPC). We sought to determine which of these two measures is a better predictor of outcomes following BCPC. Methods: A retrospective chart review was performed on patients (pts) who underwent BCPC at our institution between 2008 and 2014 for whom MPAP and PVR data were available. Baseline demographic data, preoperative hemodynamics, operative details and postoperative clinical variables were analyzed. MPAP was dichotomized at 15mmHG and indexed PVR at 3 Wood units (wu). Major morbidity was defined as need for extracorporeal membrane oxygenation, BCPC takedown, percutaneous intervention during BCPC admission, hospital length of stay greater than 1 standard deviation from the mean, or need for supplemental oxygen at discharge. Results are displayed as mean ± standard error of the mean. Results: 250 patients (136 males, 54%) were included in the analysis. Mean age at BCPC was 8.3 months (±0.34) and mean weight 6.9 kg (±0.12). 91 pts (36%) had elevated MPAP ≥15mmHg (17.4±0.27 vs 11.3±0.16). 21 pts (8.4%) had PVR >3wu (3.9±0.18 vs 1.8±.04). There were 9 (3.6%) deaths, and 49 patients (20%) sustained major morbidity. Elevated MPAP was associated with increased intubation days (5.4±1.5 vs 1.8±0.31), increased intensive care stay (10.1±1.8 vs 6.0±0.70), and increased need for sildenafil at discharge (28.5% vs 19.5%) (p<0.05). Conversely, elevated PVR was not associated with any of the variables studied. On multiple regression analysis, elevated MPAP was an independent predictor of major morbidity (p<0.05). Ventricular end diastolic pressure and need for preoperative oxygen supplementation were the only two independent predictors of mortality. Conclusions: Elevated MPAP, not PVR, is an independent predictor of morbidity following BCPC.