Abstract 21633: Relationship Between Descriptors of Coronary Atherosclerosis by Coronary Ct Angiography and Quantitative Myocardial Perfusion as Assessed by Hybrid PET/CT Imaging
Background: Although the relationship between coronary stenosis and myocardial perfusion is well established, little is known about the contribution of other anatomic descriptors of atherosclerosis burden to this relationship.
Methods: We evaluated the per-vessel associations between athero burden and myocardial flow reserve (MFR) in 73 consecutive patients undergoing quantitative 82Rubidium myocardial perfusion PET and coronary CT angiography (CTA) imaging for the evaluation of known or suspected CAD. CTA descriptors of athero burden included the quantitative diameter stenosis (DS), plaque composition (calcified, non-calcified or mixed), summed stenosis score within each coronary artery (summed of all stenosis), total plaque length, and vessel remodeling index (<1.1; 1.1–1.29; or ≥1.3). MFR was defined as the ratio of peak stress over rest myocardial blood flow.
Results: Coronary atherosclerosis was seen in 50 of 73 patients, and in 107 of 209 evaluable coronary arteries. In univariate analysis, regional MFR was associated with age (r= −0.30, P<0.001), DS (r= −0.25, P<0.001) (Figure), summed stenosis score (r= −0.23, P=0.001), number of segments with plaque (−0.22, P=0.001), and total plaque length (r= −0.15, P=0.03), positive remodeling index (r= −0.14, P=0.04), calcified (r= −0.14, P=0.036), and mixed plaque (r= −0.15, P=0.03), and noncalcified plaque (r=0.12, P=0.07). In multivariable analysis, the best model for predicting regional MFR included age (β= −0.33, P<0.001), DS (β= −1.09, P=0.02), the presence of non-calcified plaque (β= 0.17, P=0.009), and an interaction between Age*DS (β= 0.95, P=0.047).
Conclusion: Individual CTA descriptors of coronary atherosclerosis burden show modest associations with coronary flow reserve, most of which disappear after adjusting for age and degree of stenosis severity.
- © 2010 by American Heart Association, Inc.