Myocardial Scintigraphy with 99mTc-Sestamibi in Children with Kawasaki Disease

Abstract

Kawasaki disease (KD) is a systemic vasculitis syndrome of early childhood. It involves particularly the coronary arteries and may cause aneurysms and thrombotic occlusions. Echocardiography is the most useful method of detecting coronary aneurysms. Nevertheless, obstructive lesions are difficult to evaluate and often need invasive coronary angiography. An important feature of this disease is the possibility of finding coronary pathology several years after the onset. This characteristic makes KD an important cause of coronary artery disease (CAD) in young adults. Thus patients with KD and previously diseased coronary arteries should be kept under long-term control. However, coronary angiography is invasive and cannot be performed repeatedly, espe cially in young patients. As an alternative, thallium 201 scintigraphy has been employed, but its low-energy photons are suboptimal for standard gamma-camera imaging, particularly in children aged less than three years. To verify the usefulness of a noninvasive assessment of myocardial perfusion, the authors used rest and dipyridamole 99mTc-Sestamibi scan in 15 children (ranging from one to six years of age) with Kawasaki's cardiac involvement. Coronary aneurysms have been demonstrated by echocardiography in 12 patients; 8 patients were also submitted to cardiac catheterization. The sensitivity of 99mTc-Sestamibi imaging for detection of overall coronary lesions was 88% and the specificity was 93%. These data suggest that rest/dipyridamole 99mTc-Sestamibi scintigraphy is an accurate and noninvasive method for the detection and follow-up of Kawasaki's cardiac damage even in patients aged one year.