To summarize the causes of missed diagnosis in adult-type coarctation of the aorta (COA) by transthoracic echocardiography (TTE) and propose an optimized standardized scanning protocol to reduce diagnostic omissions.

A retrospective analysis was performed on 45 surgically/radiologically confirmed adult-type COA cases (23 pre-protocol optimization and 22 post-protocol optimization) diagnosed via TTE at the Second Affiliated Hospital of Nanchang University between January 2013 and February 2025. The core enhancements of the standardized scanning protocol included: systematically scanning the suprasternal notch view to obtain clear long-axis images of the aortic arch for assessing its morphology and stenosis characteristics, and routinely acquiring Doppler spectra in the abdominal aorta long-axis view (typically at the diaphragmatic level) to evaluate its hemodynamic features. The missed diagnosis rates pre- and post-protocol optimization were compared using the Fisher's exact test, with relative risk (RR) and number needed to treat (NNT) calculated.

The missed diagnosis rate by TTE significantly decreased from 34.78% (8/23) pre-protocol optimization to 4.55% (1/22) post-protocol optimization (P=0.004). The RR reduction was 87% (RR=0.13, 95% confidence interval: 0.02–0.87), and the NNT of 4 indicated that standardized protocol prevented one missed diagnosis per four patients.

Understanding the echocardiographic characteristics of adult-type COA and implementing the standardized scanning protocol can significantly reduce the missed diagnosis of adult-type COA by TTE.