Blood Test Evaluated for Suspected Obstructive Coronary Artery Disease

Coronary artery disease (CAD) also known as ischemic heart disease is a very common heart condition in the USA and one in seven deaths among Americans is caused by CAD. A common symptom is chest pain or discomfort, which may travel into the shoulder, arm, back, neck, or jaw.

CAD can cause a narrowing or blockage of the coronary arteries which are the vessels to the heart that supply the heart with blood, oxygen, and nutrients, reducing blood flow to the heart muscle. This narrowing or blockage in the coronary arteries is often referred to as obstructive CAD, characterized by the presence of atherosclerosis, or plaque.

In a collaborative trial, scientists at Duke University (Durham, NC, USA) utilized 2,370 non-diabetic patients from the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial biobank repository. Almost half of the patients (1,137) in the sub-study were randomized to the computed tomography angiography (CTA) arm. In this group, 115 (10.1%) of patients were found to have obstructive CAD, and a Corus CAD score more than 15 was associated with increased obstructive CAD likelihood. Findings from the PROMISE Trial provide independent confirmation of the association between the Corus CAD test scores and the presence and extent of coronary artery disease in patients and the likelihood of obstructive CAD.

The 1,312 patients with higher Corus CAD test scores (greater than 15) had higher event rates that were statistically different from 1,058 patients with lower Corus CAD test scores (1–15). Additionally, the results from the sub-study found that at 25-month median follow-up, the clinical event rates for patients with low Corus CAD scores (less than or equal to 15), were low and no different from negative or normal noninvasive test results using either cardiac stress testing or coronary CTA (3.2% vs. 2.6%). The Corus CAD blood test is produced by CardioDx, Inc. (Redwood City, CA, USA). The test incorporates age, sex and gene expression measurements into a single score that indicates the likelihood of obstructive CAD.

Mark Monane, MD, FACP, Chief Medical Officer of CardioDx, said, “We note the finding that clinical outcomes among the patients with the low scores on the Corus CAD blood test (approximately 45% of the study patients) were no different from patients with normal cardiac stress testing or CT-angiography. Taken together, these three results highlight the characteristics of the Corus CAD test to safely and accurately help clinicians risk stratify symptomatic patients, so that patients can potentially avoid additional cardiac testing and procedures that may be potentially unnecessary.” The study was presented at the 65th American College of Cardiology Annual Scientific Meeting, on April 3, 2016, held in Chicago, IL, USA).

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Duke University
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