Myocardial contrast echocardiography of coronary artery lesions due to Kawasaki disease

Cardiac surgical procedures for the coronary sequelae of Kawasaki disease

OBJECTIVES

The aim of this article is to make an evaluation on the clinical features of patients with Kawasaki disease who require a cardiac surgical procedure including coronary artery bypass grafting, coronary arterial aneurysmorrhaphy or heart transplantation.

METHODS

English literature of Kawasaki disease for cardiac surgery (1990-2011) was retrieved in the Pubmed database. The clinical features of the patient setting from the representative articles were collected and analyzed.

RESULTS

Patients with Kawasaki disease were very young, with some requiring a cardiac surgical procedure at a very early age. The interval between the onset and the surgical operation was 9.5±9.4 years. The prevalence of myocardial infarction and re-infarction was high. Giant aneurysm, critical stenosis with calcification and thrombus formation of the coronary arteries often warrant coronary artery bypass, heart transplantation or coronary arterial aneurysm plication. The left internal mammary artery to the left anterior descending coronary artery was the most commonly used graft in coronary artery bypass. Graft patency rate was 82.4% at 21.4±32.3 (range 0.1-252) month follow-up. The early and late mortalities of this patient setting were 0.6 and 3.0%, respectively.

CONCLUSIONS

Patients with Kawasaki disease may develop coronary artery lesions prone to aneurysmal formation with calcification and thrombus and may require coronary artery bypass at a very early age. With the left internal mammary artery as the first choice of bypass graft, the long-term patency and patient survival was satisfactory.

Contrast echocardiography: potential for the in-vivo study of pediatric myocardial preservation

BACKGROUND

Myocardial contrast echocardiography (MCE) has been used successfully during adult cardiac surgery to image myocardial perfusion. Recently it has been suggested this technique is capable of detecting microvascular injury and inflammation because sonicated albumin microbubbles adhere to activated neutrophils and, in the presence of denuded or inflamed endothelium, they persist within the microvasculature rather than passing unimpeded, which results in profound slowing of their transit rates. The technique has not previously been used during congenital heart surgery; however significant potential is suggested in this setting in which myocardial inflammation may contribute to postoperative myocardial dysfunction, a leading cause of morbidity and mortality. We have performed a preliminary study to assess the safety and feasibility of MCE in the pediatric intraoperative environment and to examine myocardial transit rates.

METHODS

Sonicated albumin microbubbles were injected with cardioplegia during bypass in 16 children (aged 3 weeks to 8.5 years). Images were collected using transesophageal echocardiography. Complications, post-bypass electrocardiographic, echocardiographic, and outcome data were recorded. Myocardial transit rates were calculated using videointensity analysis, assessed for reproducibility and correlated with demographic and intraoperative variables and postoperative outcome.

RESULTS

The technique was performed safely, with good reproducibility. Myocardial persistence of microbubbles, which occurred in 6 patients, was associated with crystalloid cardioplegia, prolonged preischemic bypass (r = 0.72, p = 0.004), or ischemic time (r = 0.69, p = 0.002).

CONCLUSIONS

Intraoperative MCE shows potential as an in vivo technique for the study of pediatric myocardial preservation.

Comparison of 201Tl SPET and treadmill exercise testing in patients with Kawasaki disease

About 4% of children with Kawasaki disease ultimately develop ischaemic heart disease. Therefore, the early detection, non-invasive monitoring and long-term follow-up of myocardial ischaemia are essential. We compared the sensitivity and specificity of 201Tl single photon emission tomography (SPET) and treadmill exercise in the detection of myocardial ischaemia in 23 patients (19 boys, 4 girls) with Kawasaki disease. They were divided into two groups according to the results of coronary angiography. Group I consisted of 11 patients with coronary abnormalities; Group II consisted of 12 patients with no coronary abnormalities. The sensitivity, specificity, false-positive and false-negative rates for detecting coronary arterial lesions were 72.7% (8/11), 58.3% (7/12), 38.5% (5/13) and 30% (3/10) for 201Tl SPET, and 45.5% (5/11), 100% (12/12), 0% (0/5) and 33.3% (6/18) for treadmill exercise, respectively. We conclude that 201Tl SPET is more sensitive than treadmill exercise for the detection of coronary arterial abnormalities, but that the specificity of treadmill exercise is better than that of 201Tl scintigraphy. Coronary artery lesions detected by coronary angiography have good concordance of ischaemic areas with perfusion defects detected by 201Tl SPET. When ischaemic findings on 201Tl SPET and/or positive treadmill exercise testing are noted, coronary angiography is strongly indicated to detect possible stenotic lesions in the coronary arteries.

Noninvasive evaluation of myocardial ischemia in Kawasaki disease: comparison between dipyridamole stress thallium imaging and exercise stress testing

The sensitivities of dipyridamole stress thallium 201 single photon emission computed tomography (SPECT) and treadmill exercise testing in the detection of myocardial ischemia were compared. Thirty-eight patients with Kawasaki disease and 11 age-matched controls participated in the study. Fifteen of the 38 patients with Kawasaki disease had marked coronary artery stenosis (> 75%) in at least one vessel. SPECT scans were obtained immediately after dipyridamole infusion and 4 hours later. The sensitivity of SPECT for detection of coronary stenosis was 80% (12/15), whereas that of treadmill exercise testing was only 33% (5/15) (p < 0.001). Although the sensitivity of SPECT significantly exceeded that of treadmill exercise testing among patients with coronary stenosis in only one vessel (p < 0.05), such benefits were not found for patients with stenosis in two or three vessels. These findings suggest that dipyridamole stress SPECT has a higher degree of sensitivity in the detection of myocardial ischemia than does treadmill exercise testing, especially for patients with single-vessel disease.

Collateral vessels assessed by myocardial contrast echocardiography in patients with coronary artery lesions after Kawasaki disease

Using myocardial contrast echocardiography (MCE), coronary arteriography, and thallium-201 myocardial imaging (TMI), we examined the characteristics and the role of collateral vessels in 35 patients with coronary artery lesions after Kawasaki disease. The male/female ratio was 25:10. The patients' ages are examination ranged from 1.0 to 20.3 years (mean, 10.8 years). The age at onset of Kawasaki disease ranged from 0.3 to 11.6 years (mean, 2.6 years). The coronary artery lesions were: dilated lesions without coexistent stenotic lesions in 5 patients (14%), localized stenosis with less than 50% narrowing in 5 patients (14%), localized stenosis with 50% or more narrowing in 4 patients (11%), and obstructive lesions, such as occlusion and/or segmental stenosis, in 21 patients (60%). In the group with no stenotic lesions and the group with less than 50% localized stenosis, the perfusion area of the right coronary artery was 32.6 +/- 8.4% and that of the left coronary artery was 76.3 +/- 7.9%. The total perfusion area of the right and the left coronary arteries was 108.9 +/- 2.6%, which value was inversely correlated with age at examination (r = 0.716, P = 0.020). In the group more than 50% localized stenosis, an increase in overlap areas detected by MCE, where a perfusion defect was seen on TMI, was not found, except in 1 patient with 99% stenosis. In the patients with obstructive lesions development of collateral channels was better in the perfusion area of the occluded right coronary artery than in that of the occluded left coronary artery, and well developed collateral channels were significantly correlated with good wall motion. We conclude that overlapping perfusion occurs in younger rather than in older children without stenotic coronary systems, and this may contribute to the food development of collateral circulation in infants and young children with coronary artery lesions after Kawasaki disease.