Potential role of bolus-tracking data of carotid CT angiography for atrial fibrillation prediction

Abstract

Objectives: Atrial fibrillation (AF), a significant cause of ischemic stroke, often goes undetected because of its asymptomatic nature. This study investigated whether the total bolus-tracking time (TTT) and average slope (AS) of a bolus-tracking graph could be used to predict AF.

Methods: This single-center, retrospective study included patients who underwent carotid CTA and a 24-h Holter test. TTT and the average degree of enhancement during bolus-tracking, derived from carotid CTA, were defined as variables of interest. All patients underwent transthoracic echocardiography. Left ventricular diastolic dysfunction and elevated left atrial pressure (LAP) were identified according to the guidelines of the 2016 American Society of Echocardiography/European Association of Cardiovascular Imaging.

Results: The final cohort comprised 716 patients, 80 of whom presented with AF. The TTT of the AF group was significantly longer (23.8 ± 5.2 s) than that of the non-AF group (18.7 ± 2.8 s); p < 0.001. The AS of the bolus-tracking graph of the AF group was 0.80 ± 0.24, which was significantly lower than that of the non-AF group 1.38 ± 0.21 (p < 0.001). TTT was associated with a significantly higher risk of AF (odds ratio [OR]: 1.36; p < 0.001) and elevated LAP (OR: 1.46; p < 0.001). In contrast, the AS of the bolus-tracking graph was not significantly associated with either AF or an elevated LAP.

Conclusion: TTT derived from bolus-tracking carotid CTA is an effective adjuvant tool for detecting AF related to left ventricular diastolic dysfunction and elevated LAP, confirmed using echocardiography.

Key points: • Atrial fibrillation is not only a significant cause of ischemic stroke but is also often masked because of its atypical and asymptomatic features. • The total tracking time, derived from bolus tracking of carotid computed tomography angiography, may be an effective adjuvant tool for detecting undiagnosed atrial fibrillation and elevated left atrial pressure in patients.

Keywords: Atrial fibrillation; Computed tomography angiography; Contrast media; Echocardiography; Stroke.