Evaluating Diagnostic Accuracy: A Comparison of Echocardiography and Catheterization in Determining Nakata and McGoon Indices for Surgical Management of Tetralogy of Fallot

Background: A key factor in deciding the surgical approach and predicting outcomes for tetralogy of Fallot (ToF) is the size of the pulmonary arteries. Objectives: The present study aims to compare the diagnostic accuracy of echocardiography with catheterization by calculating Nakata and McGoon indices for surgical decision-making in patients with ToF. Methods: This analytical epidemiological study, using a purposive (non-random) sampling method, was conducted on 120 patients with ToF. The patients underwent angiography and echocardiography. Subsequently, the Nakata and McGoon indices were calculated. Statistical analysis included both descriptive (frequency, mean, median, and interquartile range) and inferential methods. The Wilcoxon signed-rank test was used for comparing paired non-parametric measurements, and Spearman’s rank correlation was used to evaluate the strength of association between imaging modalities. A P-value < 0.05 was considered statistically significant. Results: A significant correlation was found between the results of echocardiography and angiography (P = 0.009). A statistically significant positive correlation was observed for the right pulmonary artery (RPA) (rho = 0.418; P = 0.004), descending aorta (rho = 0.652; P = 0.041), and cross-sectional area of the right pulmonary artery (CSA-R) (rho = 0.418; P = 0.004). No significant correlation was found for the McGoon ratio (rho = 0.067; P = 0.855) or for left pulmonary artery (LPA) and cross-sectional area of the left pulmonary artery (CSA-L) measurements. Conclusions: In patients with ToF, echocardiography alone may not be sufficient for definitive surgical decision-making. While echocardiography remains a safe, accessible, and cost-effective modality, its limitations necessitate the use of cardiac catheterization when precise anatomical measurements are required. However, in cases where echocardiographic images are unclear or equivocal, other methods such as CT angiography should be considered.