Angiographic and scintigraphic (perfusion and electrocardiogram-gated SPECT) correlates of clinical presentation in unstable angina.

ABSTRACT

BACKGROUND: Braunwald classification can be used as a measure of the acuteness or severity of clinical presentation of unstable angina. Gating perfusion images might provide additional information to that obtained from angiography, allowing correlations between the coronary anatomy and extent of myocardium at risk via simultaneous perfusion/function assessment. HYPOTHESIS: The aim of this study was to determine the relation between the highest levels of the Braunwald classification (class III = rest angina within 48 h of presentation; class C = postinfarction angina; class c = refractory angina) and the angiographic findings, and the extent ofperfusion and segmental wall motion abnormalities using technetium-99m ((99m)Tc) sestamibi-gated single-photon emission computed tomography (SPECT) imaging. METHODS: The study group consisted of 86 patients with unstable angina who underwent rest gated (99m)Tc sestamibi SPECT imaging and coronary angiography. Perfusion was graded on a 5-point scale (0 = normal; 4 = absent uptake) and wall motion on a 4-point scale (0 = akinesia/dyskinesia; 3 = normal) using the 20 segment model. Perfusion (PI) and wall motion indices (WMI) were calculated by adding the score of all segments and dividing this by 20. The localization, the degree of stenosis, and the morphology of the culprit lesion were assessed. Multivariate analysis was performed to identify the independent predictors of class III, C, and c angina. RESULTS: Perfusion index was higher and WMI was lower in classes III, C, and c than in classes < III, < C, and < c, respectively (all p < 0.001). Class III angina was associated with PI (p <0.0001), WMI (p< 0.0001), complex morphology (p = 0.01), and decreased Thrombolysis in Myocardial Infarction (TIMI) flow (p = 0.002); class C angina with PI (p < 0.0001), WMI (p< 0.0001), intracoronary thrombus (p = 0.007), and decreased TIMI flow (p = 0.003); and class c angina with PI (p = 0.005) and WMI (p = 0.006). CONCLUSION: The highest levels of the Braunwald classification are associated with a greater size and intensity of myocardial perfusion and wall motion abnormalities and with the angiographic findings of complex morphology, intracoronary thrombus, and decreased TIMI flow.