Abstract 15349: A Comparison of Clinical and Hemodynamic Characteristics of Pre- and Post-Tricuspid Congenital Shunts Resulting in Pulmonary Arterial Hypertension: Insights from a National Study

Abstract

Purpose: Post-tricuspid (postTri) congenital shunts have been considered to elicit an earlier progression to pulmonary arterial hypertension (PAH) than pre-tricuspid (preTri) defects. However, the clinical and hemodynamic aspects of this progression remain to be determined. Using data from the multicenter THALES Registry we compared the clinical and hemodynamic characteristics of preTri and postTri shunts resulting in PAH.

Methods: Patients (>3 months of age) with PAH associated with congenital heart disease were included into the THALES Registry. Descriptive statistics are expressed as means+standard deviations. Patients were stratified according to their congenital defect (preTri or postTri) and clinical and hemodynamic characteristics were compared using the Mann-Whitney U and the Pearson Chi-Square tests.

Results: The study population comprised 1034 APAH-CHD patients. The 6MWD was 369±120m. Mean pulmonary arterial systolic pressure (PAPs) and PAPm were 84.5± 29,4 and 54.7±22.2 mmHg; right atrial pressure (RAP) and PCWP were 9.0±3.1 and 11.0±3.2 mmHg; transpulmonary and transsystemic pressure gradients (TPPG, TSPG) were 45.0± 22.1 and 70.5±17.6 mmHg; Qp/Qs and PVR/SVR ratios were 3.34± 4.84 and 0.38±0.47; and mixed venous, pulmonary arterial and systemic arterial O2 saturations (mVO2%, PAO2% and SAO2%) were 65.6±11.3%, 80.8±9.4% and 91.4±7.6%, respectively. PreTri and postTri defects were recorded in 197 (19%) and 837 (81%) patients. The postTri subgroup were younger at PAH diagnosis than the preTri (12.6+13.9 vs 35.2+21.1 years; p < 0.0001) whereas gender, 6MWD, mVO2, PAO2 and SAO2 were comparable between both subgroups (p=NS). The postTri subgroup had statistically significantly higher PAPs (87.3+28.5 vs 70.9+30.3 mmHg; p<0.0001), PAPm (56.8+21.7 vs 45.5+21.8 mmHg; p<0.0001) and PVR/SVR ratio (0.41+0.51 vs 0.28+0.27; p<0.01) than the preTri subgroup, while the TSPG and Qp/Qs ratio were not significantly different.

Conclusions: Our multicenter registry on APAH-CHD confirms the more aggressive nature of postTri congenital shunts than preTri defects in terms of an early age onset of PAH, higher pulmonary arterial pressures and PVR/SVR ratio. However, these differences may not extend to functional status and O2 saturations.