Risk Factors for an Elevated Ventricular End-Diastolic Pressure Prior to the Fontan Operation.

Abstract

Systemic ventricular end-diastolic pressure (SVEDP) is an important determinant of pulmonary artery pressure in those with a Fontan circulation. Predictors of an elevated SVEDP have been incompletely identified in this population. All who underwent the Fontan operation at our center between 1/2009 and 12/2013 were retrospectively identified. SVEDP at the pre-Fontan catheterization and other patient variables were extracted. We identified 61 patients. Pre-Fontan SVEDP was positively associated with systemic ventricular systolic pressure (β=0.4, p=0.004), aortic systolic pressure (β=0.3, p=0.007), aortic mean pressure (β=0.3, p=0.02), and decreased ventricular systolic function (p=0.03). Compared to those with pre-Fontan SVEDP≤7mmHg, patients with SVEDP>7mmHg had higher average ventricular systolic pressure (85.0±7.5 vs. 78.7±8.3mmHg, p=0.003), higher average descending aorta mean pressure (62.4±4.9 vs. 58.6±8.1mmHg, p=0.03), and a higher incidence of decreased ventricular systolic function (36 vs. 15%, p=0.07). For those with a systemic right ventricle, the SVEDP decreased significantly from the pre-Stage 2 to pre-Fontan measurements (8.7±2.6 vs. 7.3±2.0mmHg, p=0.02), but not for those with a systemic left ventricle (7.8±2.0 vs. 7.2±1.8mmHg, p=0.3). At pre-Fontan catheterization, decreased ventricular systolic function and markers of systemic afterload were positively associated with the SVEDP. SVEDP decreased significantly after Stage 2 for those with a systemic right ventricle, but not for those with a systemic left ventricle; the systemic right ventricle may be particularly vulnerable to pre-Stage 2 volume loading.