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

Abstract

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. 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 periodwere 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. 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). 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.