Kawasaki disease (KD) is the leading cause of acquired heart disease in children and can result in life-threatening coronary artery aneurysms in up to 25 % of patients. These aneurysms put patients at risk of thrombus formation, myocardial infarction, and sudden death. Clinicians must therefore decide which patients should be treated with anticoagulant medication, and/or surgical or percutaneous intervention. Current recommendations regarding initiation of anticoagulant therapy are based on anatomy alone with historical data suggesting that patients with aneurysms ≥8 mm are at greatest risk of thrombosis. Given the multitude of variables that influence thrombus formation, we postulated that hemodynamic data derived from patient-specific simulations would more accurately predict risk of thrombosis than maximum diameter alone. Patient-specific blood flow simulations were performed on five KD patients with aneurysms and one KD patient with normal coronary arteries. Key hemodynamic and geometric parameters, including wall shear stress, particle residence time, and shape indices, were extracted from the models and simulations and compared with clinical outcomes. Preliminary fluid structure interaction simulations with radial expansion were performed, revealing modest differences in wall shear stress compared to the rigid wall case. Simulations provide compelling evidence that hemodynamic parameters may be a more accurate predictor of thrombotic risk than aneurysm diameter alone and motivate the need for follow-up studies with a larger cohort. These results suggest that a clinical index incorporating hemodynamic information be used in the future to select patients for anticoagulant therapy.

Patients with coronary artery aneurysms (CAAs) resulting from Kawasaki disease (KD) are at risk for thrombosis and myocardial infarction. Current guidelines recommend CAA diameter ≥8 mm as the criterion for initiating systemic anticoagulation. Transluminal attenuation gradient (TAG) analysis has been proposed as a noninvasive method for evaluating functional significance of coronary stenoses using computerized tomography angiography (CTA), but has not previously been used in CAA. We hypothesized that abnormal hemodynamics in CAA caused by KD could be quantified using TAG analysis. We studied 23 patients with a history of KD who had undergone clinically indicated CTA. We quantified TAG in the major coronary arteries and aneurysm geometry was characterized using maximum diameter, aneurysm shape index, and sphericity index. A total of 55 coronary arteries were analyzed, 25 of which had at least 1 aneurysmal region. TAG in aneurysmal arteries was significantly lower than in normal arteries (− 23.5 ± 10.7 vs −10.5 ± 9.0, p = 0.00002). Aneurysm diameter, aneurysm shape index, and sphericity index were weakly correlated with TAG (r2 = 0.01, p = 0.6; r2 = 0.15, p = 0.06; r2 = 0.16, p = 0.04). This is the first application of TAG analysis to CAA caused by KD, and demonstrates significantly different TAG values in aneurysmal versus normal arteries. Lack of correlation between TAG and CAA geometry suggests that TAG may provide hemodynamic information not available from anatomy alone. TAG represents a possible extension to standard CTA for KD patients who may improve thrombotic risk stratification and aid in clinical decision making.

Background: Awareness of Kawasaki disease (KD) is emerging in Russia but the diagnosis is still often missed.Methods: This is a retrospective study of 303 children with KD who received care at a single center in Moscow over the period from 2004 to 2016.Results: Overall, coronary artery aneurysms were documented in 91 (30,0%) of 303 patients and transient ectasia in 40 (13,2%). Intracoronary thrombi were found in 12 of 15 patients with giant aneurysms and in 3 patients with medium-sized aneurysms.Conclusion: The patients with KD in the Moscow region had typical features of the disease described in the literature but the proportion of patients with coronary artery aneurysms was higher than reported from other countries. We assume that this is due to delayed treatment, which has gradually improved over time. Increased awareness of KD in Russia is critical to ensure timely diagnosis and treatment.

Background: Coronary artery aneurysms (CAA) put patients (pts) at risk for thrombosis and myocardial infarction. Clinical guidelines recommend systemic anticoagulation for giant CAA, diameter ≥ 8mm. Pt-specific modeling and computer simulations in KD pts suggest that hemodynamic data can predict regions with increased risk of thrombus formation and may be superior to simple assessment of the geometry of the aneurysm. Specifically, regions with high Particle Residence Time gradients (PRTg) have correlated with regions of thrombus formation. Methods: Transluminal Attenuation Gradient (TAG) is determined from the change in radiological attenuation on CT angiography (CTA) images in Hounsfield units per vessel length. TAG analysis has been used for characterizing coronary artery stenoses; however this approach has not been used for CAA. We analyzed the correlation between TAG and PRTg in KD pts with CAA and evaluated TAG for prediction of thrombotic risk. Results: Pt-specific anatomic models for flow simulations were constructed from CTA image data from 6 KD pts with CAA and one normal control. TAG was calculated for all aneurysmal vessels and one control vessel. TAG values for the CAA were markedly lower than for the non-aneurysmal vessel (mean -23.76 vs. -2.21). In addition, TAG values were compared to PRTg and other hemodynamic data obtained for each pt. Conclusion: TAG analysis is a new technique that can be applied to pt data obtained non-invasively through CTA. Thrombotic risk stratification for CAA and decisions about whether to start systemic anticoagulation may be improved by incorporating TAG and should be evaluated in future prospective studies.