Abstract 672: Prediction of Ischemia on Myocardial Perfusion Imaging With Multislice Computed Tomography Coronary Angiography
Background: Previous studies have shown that the presence of stenosis on multislice computed tomography (MSCT) has a poor positive predictive value for presence of ischemia on myocardial perfusion imaging (MPI). Therefore, identification of features on MSCT that may imply a higher likelihood of ischemia may facilitate clinical management following MSCT.
Objective: To identify variables on MSCT angiography that may predict ischemia on MPI.
Methods: Both MSCT and MPI were performed in 616 patients with known or suspected CAD. Based on MSCT angiography, the presence, location, extent and degree of stenosis (>50% luminal narrowing or not) were determined. Lesions were classified as non-calcified, mixed and calcified. Ischemia on MPI was defined as a summed stress score (SSS) >4.
Results: Ischemia was observed in 28% (n=168) of patients. Multivariate analysis showed that location of atherosclerotic disease (left main and/or proximal left descending artery) (OR 1.7, p=0.03), extent of disease (≥ 3 diseased segments) (OR 1.6, p=0.03) and degree of stenosis (presence of >50% luminal narrowing) (OR 3.4, p<0.05) were independent predictors of ischemia. Interestingly, plaque composition (the presence of ≥3 mixed plaques) was also predictive for ischemia (OR 2.9, p<0.05). These variables provided significant incremental value over clinical characteristics for the prediction of ischemia (figure⇓).
Conclusions: MSCT variables describing location, extent, degree and composition of atherosclerosis are predictive for ischemia on MPI. Integration of these variables may improve identification of patients with a higher likelihood of ischemia.