Takashi Hayano

Transformation of coronary artery aneurysm to obstructive lesion and the role of collateral vessels in myocardial perfusion in patients with Kawasaki disease

OBJECTIVES The aim of this study was to examine the transformation of coronary artery aneurysms to obstructive lesions and to assess the role of collateral vessels in patients with Kawasaki disease. BACKGROUND Coronary artery aneurysms, especially giant aneurysms, are known to become obstructive lesions in patients with Kawasaki disease. However, the process of transformation is not yet clear. METHODS Thirty patients (average age 9.9 years) with obstructive lesions secondary to Kawasaki disease underwent repeated coronary artery angiography and thallium myocardial scintigraphy over a mean period of 7.7 years after the acute onset of Kawasaki disease. RESULTS In the 27 patients who were enrolled in the acute phase of the disease because of coronary artery aneurysms, the later transformation to obstructive lesions was not significantly different between the 61 large and 6 medium-sized aneurysms. Obstructive transformation of aneurysms was more rapid in the right than in the left coronary artery (p < 0.001). From the last coronary angiogram obtained, the obstructive lesions were classified as localized stenosis > 90% in 10 vessels, occlusions in 6 vessels and segmental stenosis in 26 vessels. Both localized and segmental stenosis occurred significantly more often in the left anterior descending and the right coronary artery than in other vessels (p < 0.05). The incidence of collateral vessels was significantly correlated with a younger age at onset of Kawasaki disease, especially in patients with segmental stenosis (p < 0.001). Collateral vessels did not develop in the presence of localized stenosis regardless of the occurrence of myocardial ischemia. All occluded vessels had collateral development regardless of the presence of myocardial infarction. CONCLUSIONS The treatment of localized stenosis may play an important role in preventing myocardial infarction in the chronic phase of Kawasaki disease.

Asymptomatic myocardial infarction in Kawasaki disease: Long-term prognosis

SummaryEight patients with Kawasaki disease who had sustained asymptomatic myocardial infarction 8–15 years ago (mean, 13.1 years) were reexamined by various noninvasive cardiac function tests to assess long-term prognosis.At present, electrocardiograms (ECGs) are normal in six patients. However, all eight patients had a prolonged preejection period (PEP) to left ventricular ejection time (LVET) ratio 30 s after amylnitrate (AN) inhalation. Six patients had perfusion defects by exercise thallium-201 myocardial scintigraphy, and two patients developed ST segment depression in treadmill exercise testing.These patients are symptom-free even though their physical activity has not been restricted. Yet they proved to have serious abnormalities suggesting sequelae of myocardial infarction or existing myocardial ischemia. Judging from the results of noninvasive cardiac function tests and recently performed coronary angiography, five of the eight patients require coronary bypass surgery.

A child case of acute right coronary obstruction due to catheter-induced coronary dissection: successful reperfusion without stenting.

We report on a 10-year-old child who suffered from acute right coronary obstruction due to catheter-induced coronary dissection. Immediate placement of a perfusion catheter into the obstructed right coronary artery and subsequent overnight reperfusion allowed successful recovery of the right coronary artery lumen without implantation of a stent. Follow-up angiography demonstrated spontaneous regression of the dissected coronary artery and normal right and left ventricular wall motion. The indication of stent implantation should be carefully determined in a child case of iatrogenic coronary dissection because stenting may induce coronary stenosis during growth.