Corus CAD

Simple blood test can help clinicians assess patient's risk of heart problems

February 13, 2017
by John W. Mitchell, Senior Correspondent
Primary care doctors now have an accurate and affordable blood test at their disposal to determine if a patient with chest pain has a big problem or not.

The results of a peer-reviewed trial study published in the February issue of the American Heart Journal found that Corus CAD, a blood test developed by CardioDX, can help doctors determine whether or not their patient’s symptoms are due to a heart artery blockage. The test result was also found in the study to be associated with future coronary artery disease (CAD) events, specifically a patient’s likelihood of having a revascularization procedure.

"CAD-related events have historically had, and continue to have, a significant impact on patient morbidity and mortality, and are very costly to patients and to the health care system as a whole," Pamela Douglas, M.D., principal investigator of the main study and professor of research in cardiovascular disease, Duke University Medical Center, told HCB News.

The findings were the result of a subset study of the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE). The sub-study was done under the auspices of the National Heart, Lung and Blood Institutes' effort to assess the blood test, which generates an age, sex and gene expression score (ASGES) to determine risk.

"The test helps clinicians rule out obstructive coronary artery disease as the cause of the patient’s symptoms," Dr. Mark Monane, FACP and Chief Medical Officer at CardioDX told HCB News. "The Corus test provides a 96 percent likelihood that a person with a low score does not currently have obstructive coronary artery disease."

He added that the Corus CAD score is especially helpful in patients with atypical CAD symptoms like abdominal pain or fatigue. Women and elderly patients, he noted, often present with atypical symptoms of obstructive CAD.

According to Douglas, when obstructive CAD is categorized as unlikely through a low ASGES (Corus) score, clinicians might also use this information to help patients avoid unnecessary procedures. This could include invasive cardiac catheterization and exposure to radiation and/or dyes from such tests.

Such a protocol would be less invasive for the patient while reducing unnecessary health care costs.

"Predicting the presence of coronary artery disease in patients with chest pain and the need for related procedures is a priority in cardiac care," explained Douglas. "We want to know as early as possible whether the cause of the patient's symptoms is likely CAD related ... or whether we can confidently say that we need to pursue non-cardiac causes."

She said that the top line findings in the retrospective study demonstrated that a low ASGES score correlated with low risk of a major cardiac event going forward for 25 months. The study encompassed 2,370 non-diabetic patients from the PROMISE trial biobank repository. The findings in this blood test subgroup remained constant even after adjusting for common clinical risk factors.

According to Douglas, the results of the PROMISE sub-study provides observational data supporting further prospective exploration of potential uses of the ASGES blood test in heart health evaluation.

"It's exciting to have the ability to potentially simplify a patient's care in the primary care setting, as well as reduce cost for the patient and cost to the health care system," said Douglas.