AIM: Percutaneous transluminal coronary angioplasty (PTCA) has become increasingly important in patients with multivessel ischemic heart disease without surgical indication. The aim of the present study was to evaluate the usefulness of myocardial perfusion scintigraphy in discriminating the functional significance of coronary obstruction in patients with multivessel disease.
METHODS: Thirty four patients with multivessel coronary artery disease were included in the study (17 females, mean age 63.2 yrs). Twenty four patients (70.5%) had triple vessel disease, with at least 50% obstruction of the left anterior descending (LAD), left circumflex (CXA) and right coronary arteries (RCA). The other 10 patients had at least 50% obstruction in the same arteries or their main branches. All patients were submitted to myocardial perfusion scintigraphy with [Tc-99m] sestamibi at rest and after exercise (7 patients) or pharmacological stress with dipyridamole (27 patients). All patients were submitted to coronary angiography within 6 months of the scintigraphy. The perfusional defects were associated to coronary arteries according to the American Heart Association recommendations for tomographic imaging: anterior, antero-septal and apex (LAD territory), antero-lateral and inferior-lateral (CXA territory) and inferior and inferior-apical (RCA territory).
RESULTS: Perfusion defects were detected in 3 territories in 3/34 patients (8.8%), in 2 territories in 13/34 patients (38.2%) and in 1 territory in 16/34 patients (47%). No perfusion defects were found in 2/34 patients (5.8%). One of these two patients presented transient ischemic dilation (subendocardial ischemia).
CONCLUSIONS: Most patients with multivessel coronary artery disease at angiography present perfusion defects in only 1 or 2 territories on myocardial perfusion scintigraphy. This information should be used for decision making as to which territories to treat with angioplasty. A false negative study is a rare finding.
