Accuracy of Current Non-invasive Methods in Estimating Aortic Coarctation Gradients

Abstract

Aims: To understand the accuracy of non-invasively obtained blood pressure gradients (cuff vs Doppler gradient) with an invasively measured pressure gradient.
 Study Design: Retrospective study.
 Place and Duration of Study: Department of Pediatrics, Section of Pediatric Cardiology, King Faisal Specialist Hospital & Research Center, Jeddah, Saudi Arabia, between Jan, 2010 till Jan, 2020.
 Methodology: A retrospective study of patients with CoA who underwent cardiac catheterization between Jan, 2010 till Jan, 2020 was performed. Cuff BP gradients and Doppler echocardiography were measured prior to cardiac catheterization and afterwards, when an intervention was performed. Student t test and Bland-Altman analysis were performed.
 Results: 55 patients with aortic coarctation underwent 92 cardiac catheterizations. Among them 75 needed interventions. This resulted in a total of 162 cardiac catheterizations (cath), from them 67 pressure gradients included in the analysis. There was no statistically significant difference between mean Doppler measurements and invasively derived catheter gradients (p=0.12). In contrast peak Doppler measurement (p < 0.00001) and cuff blood pressure gradients (p=0.03) showed significant differences to the cath gradient. We found that cuff blood pressure gradients accurately reflected cath measurement in native COA (p=0.40) and in those who weigh less than 10 kg (p=0.67). Mean Doppler measurements had a small tendency for underestimation. Peak Doppler gradient and cuff pressure gradient usually overestimated cath measurement. 
 Conclusion: The mean Doppler echocardiography seems to be the most accurate among the other noninvasive methods in use to estimate severity of aortic coarctation. It provided reasonable agreement with the invasively obtained aortic coarctation gradient.

Using computed tomography angiography and computational fluid dynamics to study aortic coarctation in different arch morphologies

“…Further improve CTA examination to diagnose CoA with extensive vertebral collateral supplying the descending aorta, the diameter of the lumen of the surgically resected aortic isthmus is less than 1 mm. Thus, the velocity is measured by TTE, then calculating the pressure gradient generated by blood flow from the Bernoulli equation ( 36 ). The greater the velocity of blood flow to the aortic wall, the greater the pressure gradient between the ends of the stenosis.…”