CT coronary angiography as an alternative imaging method to ascertain cardiac output and its correlation with echocardiography

Abstract

To assess the feasibility and accuracy of cardiac output (CO) obtained using a test bolus in patients scanned with single-source prospective-gated cardiac computed tomography (CT), and comparing it with CO obtained from unenhanced two-dimensional (2D) echocardiography using biplane Simpson's method. In the present study, 100 patients with a mean age of 55±12 years who underwent coronary CT angiography with prospective electrocardiogram (ECG)-gated CT in which the scan delay was evaluated using a test bolus. The time-attenuation curves obtained from the test bolus were used to calculate the CO of the patients. The CO obtained was then compared with that obtained after follow-up 2D echocardiography using biplane modified Simpson method. Linear regression was calculated between the CO and contrast enhancement: CO=-0.16(HUmax)+7.65. The study showed good correlation between the two methods with r=0.77, p<0.001. On Bland-Altman analysis, no significant difference was noted between the two methods. This less researched method for CO estimation appears feasible; however, the clinical usefulness of this parameter is uncertain in absence of further clinical and reference standard validation.