Mariana Diaz-Zamudio MD, Abstract Co-Author: Nothing to Disclose

Tobias A. Fuchs MD, Abstract Co-Author: Nothing to Disclose

Damini Dey PhD, Presenter: Research support, Siemens AG

Piotr Jan Slomka PhD, Abstract Co-Author: Nothing to Disclose

Reza Arsanjani, Abstract Co-Author: Nothing to Disclose

Heidi Gransar, Abstract Co-Author: Nothing to Disclose

Guido Germano, Abstract Co-Author: Nothing to Disclose

Daniel S. Berman MD, Abstract Co-Author: Research Grant, Lantheus Medical Imaging, Inc Research Grant, Astellas Group Research Grant, Siemens AG Speaker, Bristol-Myers Squibb Company Speaker, Covidien AG Speaker, Astellas Group Stockholder, Spectrum Dynamics Ltd Consultant, Bracco Group Consultant, FlouroPharma, Inc

Philipp A. Kaufmann MD, Abstract Co-Author: Researcher, General Electric Company

We aimed to investigate if quantitative plaque burden and luminal contrast density differences measured from coronary CT angiography (CTA) predict ischemia by SPECT in men and women.

184 (62% Males) consecutive patients with suspected coronary artery disease (CAD), undergoing hybrid CTA and stress/rest myocardial perfusion SPECT scans, with calcium score ≤1000, no severe motion artifacts and no multi-vessel disease were considered. From CTA, arteries were evaluated by automated software (AUTOPLAQ) deriving non-calcified (NCP), low-density NCP [LDNCP, attenuation <30 Hounsfield Units (HU)], and total plaque (TP) burdens (%, normalized to vessel volume), maximum diameter stenosis (DS), remodeling index (RI) and contrast density difference (CD, maximum difference in HU/lumen area). Regional ischemia (≥2% stress-rest perfusion deficit) was automatically derived from attenuation-corrected Cadmium-Zinc-Telluride (CZT) SPECT.

Plaque measures were higher in arteries corresponding to ischemic regions [DS 43.6 vs 22.9%; NCP 23.0 vs 13.6%; LDNCP 4.2 vs 1.9%; TP 25.5 vs 15.5%; RI 1.06 vs 0.7; CD 26.5 vs 10.0%; p<0.0002 for all] with higher per-vessel prevalence of LDNCP≥7% and CD≥45%. In multivariable analysis, both LDNCP≥7% and CD≥45% predicted ischemia in overall population (LDNCP: OR 4.98; CD: OR 7.6, p<0.002), and separately in men (LDNCP: OR 5.03, p<0.0001; CD: OR 5.29, p=0.03) and women (LDNCP: OR 5.4, p=0.037; CD: OR 12.1, p=0.006). When adjusted for DS ≥50%, both LDNCP and CD persisted as the strongest ischemia predictors in overall population (LDNCP: OR 3.67, p=0.002; CD: OR 5.1, p=0.008; DS: OR 1.94, p=0.04), but only LDNCP in men (OR 3.66, p=0.005) and CD in women (OR 10.94, p=0.025) predicted ischemia. Further, in a sub-analysis of vessels with stenosis severity ≥50% (figure), only LDNCP predicted ischemia in men (OR 4.04, p=0.016) and CD predicted ischemia in women (OR 8.62, p=0.031).

Quantitative CTA measures of LDNCP and CD predict ischemia by SPECT independent of stenosis. There are gender-based differences in quantitative CTA features that predict ischemia: LDNCP burden is the strongest predictor for ischemia in men, while CD is the strongest predictor in women.

From our study of patients undergoing hybrid CTA and SPECT in an unbiased population, quantitative CTA features may be important for elucidating the pathophysiology of myocardial ischemia in men and women.

Diaz-Zamudio, M, Fuchs, T, Dey, D, Slomka, P, Arsanjani, R, Gransar, H, Germano, G, Berman, D, Kaufmann, P, Quantitative Coronary Plaque Burden and Contrast Density Difference from Coronary CTA Predict Ischemia by SPECT in Men and Women.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14011663.html