Abstract 15373: The Clinical and Hemodynamic Characteristics of Transition to Eisenmenger Syndrome in Pulmonary Arterial Hypertension Associated with Congenital Heart Disease: A National Multicenter Study

Abstract

Purpose: Although pulmonary arterial hypertension (PAH) associated with congenital heart disease (APAH-CHD) may show a progression to Eisenmenger Syndrome (ES), the clinical and hemodynamic aspects of the gray zone between the two states remain to be determined. The aim of this study was to examine the differential clinical and hemodynamic characteristics of transition to ES in patients with APAH-CHD.

Methods: Patients (>3 months of age) with APAH-CHD, who were included into THALES (Turkish Congenital Heart DiseAse PuLmonary HypErtension Study) Registry, were stratified into 3 groups: Group A Qp/Qs=1; Group B Qp/Qs=1-1.5; and Group C Qp/Qs >1.5. Descriptive statistics are presented as means+standard deviations. Inter-group comparisons were made using Mann-Whitney U and the Pearson Chi-Square tests for non-parametric and nominal variables, respectively.

Results: Among the clinical and hemodynamic characteristics for the total population of 1034 APAH-CHD patients; age and 6MWD were comparable among three groups (p=NS). Group A had significantly lower systemic arterial O2 saturations (SAO2) vs B and C (p<0.0001 for both comparisons) and pulmonary arterial O2 saturations (PAO2) (p<0.05 vs B and P<0.0001 vs C). Group B had a significantly higher mixed venous O2 saturation (mVO2) vs C (p<0.0001). Pulmonary arterial systolic pressure (PAPs) was significantly higher in Group A and B vs C (p<0.0001 for both comparisons). PAPm was higher in Group A vs B (p<0.01) and C (p<0.001) and in Group B vs C (p<0.0001). Right atrial pressure (RAP) was significantly higher in Group A vs B and C (p<0.05 for both comparisons). PCWP were not significantly different between the groups (p=NS). Group C had a lower PVR/SVR ratio vs A and B (p<0.0001 for both comparisons). There was a significant difference between Group A vs B and C (p=0.017 vs B and P=0.001 vs C). and Group B vs C (p<0.001) with regards to transpulmonary pressure gradient (TPPG).

Conclusions: Our study revealed that a change in shunt direction, as defined by the Qp/Qs ratio, was associated with significant changes in hemodynamic measures and blood O2 saturations. However, change in the direction of the shunt was not predicted by age or 6MWD.