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Corus CAD Frequently Asked Questions

What is the Corus CAD test?

Corus CAD is a convenient blood test that helps your doctor quickly, accurately, and safely assess the likelihood that you have a significant narrowing in your coronary arteries (the arteries supplying blood to your heart), also known as obstructive coronary artery disease (CAD).* Corus CAD is the only sex-specific test for obstructive CAD that takes into consideration cardiovascular differences between men and women. The test has been clinically validated in two published studies with data that included both men and women.1,2

How is the Corus CAD test performed?

Similar to other laboratory tests, your physician must order the Corus CAD test for you. The test requires a small blood sample, which can be obtained on the same day as your initial appointment. The sample will then be shipped to the CardioDx Commercial Laboratory for analysis, and results are sent to your doctor within a few days of shipment. Your doctor will contact you to discuss your test results and help you understand what the information in your test report means.

What does the Corus CAD test measure?

The Corus CAD test will analyze your blood and measure the activity, or gene expression, of genes, which is combined with your age and sex to generate a score. The Corus CAD score indicates the likelihood that you have a significant narrowing or blockage in the heart arteries, as seen in the PREDICT and COMPASS clinical studies.1,2

What is gene expression?

Gene expression is the term used to describe gene activity, or production of RNA (ribonucleic acid), in response to environmental factors. Gene expression occurs throughout a person's life in most cells and tissues. Gene expression can change in response to disease and other conditions. Some tests incorporate gene expression to help doctors assess a patient's disease status. Gene expression tells you what's happening in your body right now.

How can the Corus CAD test help me?

After the Corus CAD test is performed, your doctor will receive a patient report with your test score. The score, along with other clinical information about you, can help your doctor assess your likelihood of having a significant narrowing or blockage in your heart arteries.

Will my insurance cover the Corus CAD test?

CardioDx is committed to providing access to the Corus CAD test for all patients, regardless of their insurance coverage or ability to pay for the test. The Corus CAD test is a covered benefit by Medicare, Aetna, and Coventry Health, and CardioDx is actively pursuing additional insurance company coverage. If you have any questions about insurance coverage, billing, or financial assistance for the Corus CAD test, please contact the CardioDx reimbursement team at 1.866.941.4996 and select option 1 or email You may also download our Patient Cost Information brochure.

How reliable is the Corus CAD test?

The Corus CAD test has been validated in two U.S. clinical studies called PREDICT and COMPASS, with 526 and 431 patient samples, respectively.1,2 The PREDICT validation study included 526 nondiabetic male and female patients, and results were published in October 2010 in the medical journal Annals of Internal Medicine. The COMPASS study, which builds on the results of the previous PREDICT validation study, was designed to provide additional independent validation of the Corus CAD test in a population of 431 male and female patients referred for myocardial perfusion imaging (MPI), a common noninvasive test for CAD. This population more appropriately reflects the real-world patient population for Corus CAD than the PREDICT study, as indicated by the lower disease prevalence. COMPASS evaluated results in nondiabetic patients with non-acute typical or atypical symptoms suggestive of obstructive CAD. The study found that the Corus CAD test has an NPV of 96% in the evaluation of obstructive CAD and more accurately assessed the likelihood of obstructive CAD than MPI. Based on these results, the Corus CAD test may help a doctor rule out obstructive CAD as the cause of the patient’s symptoms.

* Obstructive CAD is defined as at least one atherosclerotic plaque causing ≥50% luminal diameter stenosis in a major coronary artery (≥1.5 mm lumen diameter) as determined by invasive quantitative coronary angiography or coronary computed tomography angiography (≥2.0 mm lumen diameter).

Please see COMPASS study exclusion and inclusion criteria. Thomas GS, Voros S, McPherson JA, et al. Circ Cardiovasc Genet. 2013;6(2):154-162.

The COMPASS study found that the Corus CAD test has an NPV of 96% at the pre-specified score threshold of 15 in the overall population of men and women referred to MPI.

  1. Rosenberg S, Elashoff M, Beineke P, et al. Multicenter Validation of the Diagnostic Accuracy of a Blood-Based Gene Expression Test for the Assessment of Obstructive Coronary Artery Disease in Nondiabetic Patients. Ann Intern Med. 2010;153:425-434.
  2. Thomas GS, Voros S, McPherson JA, et al. A Blood-Based Gene Expression Test for Obstructive Coronary Artery Disease Tested in Symptomatic Nondiabetic Patients Referred for Myocardial Perfusion Imaging: The COMPASS Study. Circ Cardiovasc Genet. 2013;6(2):154-162.