Is It Possible to Predict False-Positive Exercise Stress Echocardiography Results by Measuring the Left Atrial Antero-Posterior Diameter?

Background: Left atrial (LA) size is a well-known prognostic determinant in the setting of coronary artery disease (CAD). No previous study has evaluated LA antero-posterior (A-P) diameter as a potential screening method for identifying individuals with a low probability of CAD. We aimed to assess the influence of LA A-P diameter adjusted for chest wall conformation (A-P thoracic diameter) on the occurrence of false-positive (FP) results on exercise stress echocardiography (ESE) in patients with suspected CAD.

Methods: All consecutive patients who had undergone coronary angiography at MultiMedica IRCCS (via San vittore 12, 20123, Milan, Italy) within two months from a positive ESE over a seven-year period were retrospectively analyzed. All patients underwent LA A-P diameter/A-P thoracic diameter ratio assessment, resting transthoracic echocardiography, and subsequent ESE. The primary endpoint was FP-ESE, defined as a positive ESE with no evidence of obstructive CAD (≥70% stenosis in any epicardial coronary artery) on subsequent coronary angiography.

Results: A total of 160 patients (64.4±13.0 years, 56.9% females) with a positive ESE were retrospectively analyzed. In light of coronary angiography results, 129 patients (80.6%) had an obstructive CAD, while 31 (19.4%) did not (FP). On the multivariate logistic regression analysis, the LA A-P diameter/A-P thoracic diameter ratio (odds ratio (OR) 0.42, 95% confidence interval (CI) 0.31-0.57) showed a strong inverse correlation with the primary endpoint. An LA A-P diameter/A-P thoracic diameter ratio ≤0.25 had 100% sensitivity and 85% specificity for predicting FP-ESE results (area under the curve (AUC) = 0.94). A strong linear correlation was demonstrated between the LA A-P diameter and A-P thoracic diameter (r = 0.85), whereas the correlation between the LA volume index and A-P thoracic diameter was moderate (r = 0.47).

Conclusions: Echocardiographic assessment of the LA A-P diameter adjusted for the A-P thoracic diameter may allow clinicians to identify, among individuals with suspected CAD, those at lower risk of obstructive CAD.