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

Background: Braunwald classification can be used as a measure of the acuten ess or severity of clinical presentation of unstable angina. Gating perfusi on images might provide additional information to that obtained from angiog raphy, allowing correlations between the coronary anatomy and extent of myo cardium 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 wi thin 48 h of presentation; class C = postinfarction angina; class c = refra ctory angina) and the angiographic findings, and the extent of perfusion an d segmental wall motion abnormalities using technetium-99m (Tc-99m) sestami bi-gated single-photon emission computed tomography (SPECT) imaging. Methods: The study group consisted of 86 patients with unstable angina who underwent rest gated Tc-99m sestamibi SPECT imaging and coronary angiograph y. 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) us ing 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. Th e localization, the degree of stenosis, and the morphology of the culprit l esion were assessed. Multivariate analysis was performed to identify the in dependent predictors of class III, C, and c angina. Results: Perfusion index was higher and WMI was lower in classes III, C, an d c than in classes < III, < C, and < c, respectively (all p < 0.001). Clas s 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 < 0.0 001), intracoronary thrombus (p = 0.007), and decreased TIMI flow (p = 0.00 3); and class c angina with PI (p = 0.005) and WMI (p = 0.006). Conclusion: The highest levels of the Braunwald classification are associat ed with a greater size and intensity of myocardial perfusion and wall motio n abnormalities and with the angiographic findings of complex morphology, i ntracoronary thrombus, and decreased TIMI flow.