Spontaneous echo contrast in the descending aorta in patients without aortic dissection: associated clinical and echocardiographic characteristics

Abstract

The objective of the study was to evaluate the frequency, clinical and echocardiographic correlates of spontaneous echo contrast in the descending aorta in the absence of dissection. Prevalence of spontaneous echo contrast in the descending aorta in the absence of dissection, and its clinical and echocardiographic correlates were investigated in 1199 consecutive patients who underwent transesophageal echocardiography. Spontaneous echo contrast in the descending aorta was detected in 54 (4.5%) patients. Patients with spontaneous echo contrast in the descending aorta had an older age (60.6±8 vs. 40.6±14.2 years, P=0.0001), an increased prevalence of male gender (66.7 vs. 43.9%, P=0.001), an increased diameter of ascending aorta (4.2±1.0 vs. 3.3±1.1 cm, P=0.0001), an increased diameter of descending aorta (3.1±0.9 vs. 2.1±0.4 cm, P=0.0001), a higher prevalence of aortic wall calcification (9.3 vs. 0.5%, P=0.00001), complex plaque in the descending aorta (13 vs. 0.7%, P=0.0001), left ventricular dysfunction (7.4 vs. 2.1%, P<0.05), a lower incidence of severe aortic regurgitation (0 vs. 3.5%, P<0.05), a lower peak flow velocity in the descending aorta (28±9 vs. 51±21 cm/s, P<0.00001), and a lower maximal shear rate in the descending aorta (51±29 vs. 105±47 s −1, P<0.00001) compared with patients without spontaneous echo contrast in the descending aorta. However, prevalence of atrial fibrillation, mitral valve disease, intracardiac spontaneous echo contrast and/or thrombus and embolic event were not different between patients with and without spontaneous echo contrast in the descending aorta ( P>0.05). Shear rate, diameter of the descending aorta, aortic wall calcification, complex plaque in the descending aorta, absence of severe aortic regurgitation and male gender were independent variables of spontaneous echo contrast in the descending aorta. Spontaneous echo contrast in the descending aorta is a local and flow-dependent phenomenon related to aortic dilation, atherosclerosis, and decreased shear rates in the descending aorta. However, in this study, spontaneous echo contrast in the descending aorta was not found to be associated with embolic events.