A VALIDATED, PERIPHERAL BLOOD GENE EXPRESSION PATTERN CORRELATES WITH CORONARY ARTERIAL PLAQUE BURDEN BY QUANTITATIVE CORONARY ANGIOGRAPHY AND CORONARY ARTERY CALCIUM SCORING

Category: 48. Genetics and Clinical Outcomes Presentation Number: 924-4 Citation: J. Am. Coll. Cardiol. 2011;57;E1157 Authors: Szilard Voros, Michael R. Elashoff, Amy J. Sehnert, Hsiao D. Lieu, James A. Wingrove, Susan E. Daniels, Steven Rosenberg, Alexandra Lansky, Robert S. Schwartz, William E. Kraus, Eric J. Topol, Piedmont Heart Institute, Atlanta, GA, CardioDx Inc, Palo Alto, CA Abstract: Background: Coronary plaque burden can be measured indirectly by quantitative coronary angiography (QCA) and by coronary artery calcium (CAC) scoring by CT. We previously validated a real-time-PCR-based 23-geneexpression test, Corus CAD, to predict obstructive CAD using QCA (≥50% stenosis). Background: Coronary plaque burden can be measured indirectly by quantitative coronary angiography (QCA) and by coronary artery calcium (CAC) scoring by CT. We previously validated a real-time-PCR-based 23-geneexpression test, Corus CAD, to predict obstructive CAD using QCA (≥50% stenosis). Methods: In the validation cohort of the PREDICT study (NCT 00500617), 526 patients had gene expression score and QCA-derived plaque burden available and in 79 patients (49 cases, 30 controls), CAC score also. Plaque burden was defined as the sum of occluded luminal volumes for all QCA lesions; occluded volume is calculated from lesion length and reference and minimal vessel luminal diameter, assuming a symmetrical hourglass shape. Linear regression analysis was used to evaluate relationships. Results: In the 526 patients, there was significant correlation between gene expression score and QCA-derived plaque burden (p=1.4x10-8, R=0.38). In the CT subset, gene expression and CAC scores (range 0-3189; median=270) were correlated with R=0.63 (p=3x10-10). ROC analysis for the prediction of non-zero CAC by gene expression score showed an AUC 0.92. Both scores were significantly associated with disease burden by QCA (R=0.57 and 0.51,