Background: Cardiac catheterization is the gold standard to determine operability in patients with congenital heart disease (CHD) with left to right shunt and pulmonary hypertension.

Objective: To determine if systemic oxygen saturation could be used as a screening tool for acyanotic CHD patients who are operable without having to undergo an invasive procedure.

Materials and Methods: All cardiac catheterization data at the King Chulalongkorn Memorial Hospital between 2002 and 2017 were retrospectively reviewed. The inclusion criteria were acyanotic lesion with left-to-right shunt, mean pulmonary artery pressure of 25 mmHg or more, pulmonary overcirculation (Qp:Qs greater than 1), and absence of significant left sided heart disease (LAP or PCWP of less than 15 mmHg). Operability was defined as Rpi of 6 WU.m² or less and Rp:Rs of less than 0.3 in room air. The value of aortic saturation as diagnostic test for operability was analyzed by ROC curve analysis.

Results: Two hundred twenty-six patients, with a median age of two years old, (IQR 0.11, 6.00) were divided into pre-tricuspid shunt (ASD, PAPVR, 9.7%), complete atrioventricular (AV) canal defect (13%), and other post-tricuspid lesion (VSD, PDA, 77%). Aortic saturation cut-off values to predict operability with 100% specificity were 98.5% in pre-tricuspid shunt, 100% in post-tricuspid shunt group, and 94.5% in complete AV canal group.

Conclusion: In the present study population, aortic saturation may be used to determine operability in acyanotic CHD patients with pulmonary overcirculation. Diagnostic yield is best in patients with complete AV canal defect in whom oxygen saturation of 95% or above identified operability with close to 100% specificity. In other lesions, there appears to be no oxygen saturation that is safe to preclude cardiac catheterization.

Keywords: Congenital heart disease, Acyanotic heart disease, Non-cyanotic heart lesions, Pulmonary hypertension, Operability, Aortic saturation

DOI: doi.org/10.35755/jmedassocthai.2021.05.11326

Received 8 April 2020 | Revised 3 March 2021 | Accepted 9 March 2021