In Kawasaki disease coronary aneurysm combined with myocardial ischemia, in addition to lifestyle intervention and pharmacological treatment, re-establishing coronary artery blood flow through surgical or interventional methods is a more active and effective measure to prevent myocardial infarction, fibrosis, cardiac insufficiency, arrhythmia and improve prognosis.
Case report.
A child, male, 10 years old, with “no obvious discomfort”, was found to have “congenital heart disease and ventricular septal defect” since childhood, and was found to have “left coronary artery trunk aneurysm formation with an internal diameter of 10 mm and wall thickening during routine review of echocardiography. 10 mm, wall thickening, lumen irregularity and attached thrombus. The right coronary artery aneurysm had an internal diameter of 6 mm, the left ventricle was enlarged with an end-diastolic internal diameter of 45 mm, the left ventricular lower wall, lateral wall, anterior septum and apical wall were thinned, the motion was reduced, the left ventricular systolic function was reduced, and the ejection fraction was 40%.
The ECG showed II, III, AVF and V1-3 leads q-wave with T-wave inversion.
The grandparents recalled that the child had symptoms such as red eyes, red lips and rash after a high fever when he was 1 year old, but he was not systematically treated because his body temperature was soon normal.
After admission, the child was examined by blood tests, ultrasound of the arteries of the extremities and head and neck, and CT of the great vessels, excluding rheumatic immune system diseases such as nodular artery and aortitis.
The final diagnosis was “sequelae of Kawasaki disease – coronary artery aneurysm, coronary heart disease, old myocardial infarction (anterior septum, inferior wall, lateral wall, apical part), cardiac function class II”.
Treatment.
(1) Basic treatment.
Due to the risk of sudden death in the child, activity level needs to be limited and strenuous exercise is strictly prohibited. Lifestyle guidance is given to prevent early-onset coronary atherosclerosis, including avoidance of high-fat diet, weight control, and prevention of obesity. Take low-dose aspirin to prevent intracoronary atheroma thrombosis. Give Kepone, spironolactone and diuretics to maintain cardiac function.
(2) Is coronary revascularization necessary?
The coronary angiogram showed a large coronary aneurysm in the left main stem, located at the opening of the anterior descending branch and the left circumflex branch, with an aneurysm diameter of about 10 mm, calcification of the aneurysm wall, thrombus formation in the lumen, and local stenosis of 90%; (see figure). The right coronary artery aneurysm was about 6 mm in diameter with a local stenosis of about 70%;. The distal vessel lumen was all patent.
Adenosine loading ECG + nuclear myocardial imaging results were positive, suggesting the presence of myocardial ischemia.
After medical and surgical discussions, it was concluded that the child had three coronary artery lesions, especially severe stenosis in the left main stem, and significant myocardial ischemia, with a risk of sudden death; the left ventricle was enlarged, several ventricular wall segments were hypokinetic, and the left ventricular systolic insufficiency should be actively treated with coronary revascularization.
We performed coronary artery bypass grafting for the left anterior descending branch, left gyrus branch, and right coronary artery under non-extracorporeal circulation using the saphenous vein as the graft vessel.
The preoperative drug therapy was continued after the operation. Six months after the operation, the child’s activity tolerance improved significantly, but he still had discomfort in the anterior thoracic region after strenuous activities. A repeat cardiac ultrasound showed improved left ventricular systolic function with LVEF of 55%;; CT showed a patent coronary bridge.
Discussion.
Kawasaki disease is prevalent in Asian populations, with an incidence of 150/100,000 children under 5 years of age in East Asia, including Japan and Taiwan, and 10-15/100,000 in Europe and the United States, according to statistics. Kawasaki disease is a systemic vasculitis that affects mainly small and medium-sized arteries, with coronary arteries being particularly susceptible, and coronary artery aneurysms being the most serious complication. The incidence of coronary artery aneurysms used to be as high as 15-25%; currently, the incidence of coronary artery aneurysms has been reduced to 5% with the application of high-dose gammaglobulin shock therapy regimens; and the incidence of giant coronary artery aneurysms greater than 8mm in diameter is approximately 1%;. The incidence of coronary artery aneurysms is relatively high in infants with onset under 1 year of age, and in children who do not respond to gammaglobulin therapy.
The incidence of transient coronary artery dilatation in the acute phase of Kawasaki disease is about 18.8%;. Echocardiography observed that the coronary arteries generally start to dilate around 10 days after the onset of disease. However, 2/3 of cases are transiently dilated and the vast majority can return to normal after 3-5 weeks.
Coronary artery aneurysms are mainly located in the left and right coronary artery trunks and larger coronary branches, and generally do not involve small distal branches. Due to the presence of persistent endothelial insufficiency in coronary arteries after Kawasaki disease, intra-aneurysm thrombosis is often present. Coronary aneurysms, especially giant coronary aneurysms, are often complicated by luminal narrowing or even occlusion, leading to myocardial ischemia, myocardial infarction and sudden death.
According to a group of Japanese clinical data, the incidence of myocardial infarction in Kawasaki disease is 1.1%; it is the leading cause of death in Kawasaki disease. The vast majority of myocardial infarctions occur within 1 year of disease onset. Unlike adult coronary artery disease, myocardial infarction in Kawasaki disease can occur under any circumstances, more often during sleep or rest at night, and manifests as weakness, vomiting, abdominal pain, chest pain, and shock. 50%; of myocardial infarction cases may be preceded by no symptoms of myocardial ischemia, and 37%; of myocardial infarction cases are also asymptomatic at the time of occurrence. This may have something to do with the inability of children to complain of symptoms.
This data also shows that the mortality rate of the first myocardial infarction episode in Kawasaki disease is as high as 22%; due to the lack of myocardial ischemic preadaptation process and collateral vascular compensation. 16% of those who survive the initial infarction episode; will have another infarction. The mortality rate of second and third myocardial infarction reached 63%; and 83%; respectively. Most cases of death after myocardial infarction are left coronary artery trunk lesions, and surviving cases are mainly single branch lesions, especially right coronary artery lesions.
In addition to the need for long-term antithrombotic therapy and prevention of early coronary artery sclerosis, Kawasaki disease complicated by coronary aneurysm, special attention should be paid to the presence of myocardial ischemia during follow-up. If there are manifestations of myocardial ischemia (including angina symptoms, electrocardiographic or echocardiographic changes), or if there is no manifestation of myocardial ischemia but there is evidence of myocardial ischemia on stress tests (including stress nuclear myocardial perfusion imaging, flat panel exercise electrocardiography or stress echocardiography), further coronary angiography should be performed to understand the coronary artery lesions and assess the necessity and possibility of coronary revascularization therapy.
The purpose of coronary revascularization therapy is to provide blood flow to the ischemic myocardium, which is a more aggressive and effective measure to prevent myocardial ischemic necrosis, fibrosis, cardiac insufficiency, arrhythmias, and to improve the prognosis.
The indications for coronary revascularization of coronary artery aneurysms in Kawasaki disease are as follows.
(1) With symptoms of myocardial ischemia.
(2) Although there is no manifestation of myocardial ischemia, evidence of myocardial ischemia is found on stress tests (including stress myocardial perfusion imaging, electrocardiography or echocardiography, etc.).
(3) Coronary angiography shows 75% coronary artery stenosis; or more, 50% left main stem stenosis; or more, with risk of sudden death.
There are two types of coronary revascularization: surgical and interventional. However, at present, especially in China, low age and low weight are the main difficulties limiting the implementation of hemodynamic reconstruction treatment. The above case in this paper is one of the few coronary artery bypass surgery for younger children in China.
Methods of coronary artery revascularization.
(1) Interventional treatment
It is mainly applied to limited, non-opening, non-long segment coronary lesions. It includes percutaneous coronary balloon angioplasty (PTCA), coronary stent implantation, Xuanmu ablation and intracoronary thrombolytic therapy.
PTCA: requires lesions without calcification or only mild calcification, and is the first-line treatment for younger children. The pressure should not be too high when choosing to dilate, otherwise the neoplastic coronary aneurysm is likely to form. In addition, the restenosis rate after PTCA is high and can reach 15%.
Coronary artery stenting has a high lumen patency rate, prevents restenosis after PTCA, and can be used for longer segment lesions. However, it is not suitable for severely calcified lesions. It is not suitable for younger children because the operation requires a larger vascular access and requires an age >;13 years.
Xuan mill ablation: for older children with severe calcified lesions.
Intracoronary thrombolytic therapy: using intracoronary administration of t-PA thrombolysis followed by heparin anticoagulation, which is the only option for younger children.
(2) Coronary artery bypass grafting (CABG)
This is commonly referred to as coronary artery bypass grafting. CABG can be considered for left main lesions and for those who are not suitable for interventional treatment. However, because of the difficulty of performing the procedure in younger children, the optimal age for the procedure is preferably 5 years or older. In large cohort studies with a high number of cases reported in the literature, the mean age of surgery was around 10 years.
If possible, the use of the internal thoracic artery is recommended as a graft vessel, especially in younger children. This is because of the growth properties of the internal thoracic artery and the higher rate of late patency compared to the saphenous vein.