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Results from Two Studies Demonstrate the Clinical Utility of CardioDx Gene Expression Test in Patients with Suspected Obstructive Coronary Artery Disease

May 14, 2012

PALO ALTO, Calif. – May 14, 2012 – CardioDx, Inc., a pioneer in the field of cardiovascular genomic diagnostics, today announced results of two studies evaluating the role of the Corus® CAD gene expression test in clinical decision-making for the evaluation of patients with suspected obstructive coronary artery disease (CAD). Results were presented last week at the Quality of Care and Outcomes Research (QCOR) 2012 Scientific Session in Atlanta, Ga., and the Society of General Internal Medicine (SGIM) 35th Annual Meeting in Orlando, Fla.

“Every day, thousands of patients visit a primary care physician for symptoms suggestive of coronary artery disease – an enormous cost to the health care system,” said David Levison, president and CEO of CardioDx. “These two studies, which evaluated the clinical utility of the Corus CAD test in real-world clinical practice, demonstrate that Corus CAD can help identify whether or not patients need further diagnostic cardiac evaluation, helping many patients avoid invasive testing and exposure to radiation risks or imaging agent intolerance.”

John McPherson, M.D., director of the Cardiovascular Intensive Care Unit at Vanderbilt University Medical Center, in Nashville, Tenn., presented results from the prospective IMPACT (Investigation of a Molecular Personalized Coronary Gene Expression Test on Cardiology Practice Pattern) Trial at the QCOR conference on May 9.

Results of the study concluded that Corus CAD was associated with a clinically relevant and statistically significant change in diagnostic test utilization.

IMPACT enrolled non-diabetic patients referred to Vanderbilt University Medical Center cardiologists for evaluation of chest pain and related symptoms suggestive of coronary artery disease. The cardiologists’ diagnostic strategies were evaluated before and after the Corus CAD score was known in a prospective cohort of 83 patients.

Following the use of Corus CAD, a change in diagnostic testing (e.g., an increase or decrease in the use of myocardial perfusion imaging, computed tomography angiography (CTA) and/or cardiac catheterization) was noted in 58 percent of patients (p<0.001). Among patients with decreased testing, 91 percent (29/32) had low (≤15) Corus CAD scores. At 30 days and six months, no major adverse cardiovascular events were observed for any low-scoring patient who had not been referred for further testing. Among patients with increased testing, 100 percent (16/16) had non-low (>15) Corus CAD scores.

“Evaluating patients with suspected coronary artery disease often involves test overutilization and high costs,” said Dr. McPherson. “Results of the IMPACT trial show Corus CAD simplifies the diagnostic strategy for suspected symptomatic coronary artery disease. The Corus CAD test helps physicians exclude patients without obstructive CAD from unnecessary diagnostic testing while identifying patients for further cardiac work-up.”

In addition, on May 11 at the SGIM conference, Michael Conlin, M.D., Johns Creek Primary Care, Suwanee, Ga., presented results from a study evaluating the impact of the Corus CAD test on patient referrals to cardiology in 317 patients at four community-based primary care clinics in Arizona, Georgia, Louisiana, and North Carolina. The objective of the study was to assess the role of Corus CAD on clinical decision-making by community-based primary care providers considering patient referrals to cardiology for evaluation of chest pain and related symptoms suggestive of coronary artery disease.

Results of the study showed that Corus CAD significantly influenced primary care physician referral patterns to cardiologists, with low Corus CAD-scoring patients 73 percent less likely to be referred to cardiologists compared to non-low Corus CAD-scoring patients. This effect was independent of age, gender, symptoms, and practice site. The decrease in patient referrals to cardiology was accompanied by a reduction in use of non-invasive and invasive testing.

“The results of this study suggest that primary care physicians have incorporated the use of the Corus CAD score in their practices to help accurately exclude obstructive CAD as the cause of a patient’s symptoms. This can lead to more efficient and improved patient care in the primary care setting,” said Dr. Conlin, who served as the principal investigator of the study.

About Corus CAD

With a simple blood draw, Corus CAD can help primary care clinicians and cardiologists exclude obstructive coronary artery disease as the cause of a stable non-diabetic patient's symptoms. It is the first sex-specific test for obstructive coronary artery disease, accounting for critical biological differences between men and women. The test is safe and does not expose patients to radiation risks or imaging agent intolerance.

The Corus CAD test measures the RNA levels of 23 genes. Because blood RNA levels are altered when obstructive coronary artery disease is present, the Corus CAD score aids clinicians in assessing whether an individual patient’s symptoms may be due to obstructive coronary artery disease.

Corus CAD is commercially available through an innovative patient sample kit that includes everything needed for blood collection and express delivery to the company’s CLIA-certified Palo Alto, Calif. laboratory. Test results are delivered promptly to the clinician’s office. Corus CAD is currently available in the United States.

Corus CAD has been recognized by The Wall Street Journal’s Technology Innovation Awards, honored as a Gold Edison Award recipient, and named one of TIME’s Top Ten Medical Breakthroughs.

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About CardioDx

CardioDx, Inc., a pioneer in the field of cardiovascular genomic diagnostics, is committed to developing clinically validated tests that empower clinicians to better tailor care to each individual patient. Strategically focused on coronary artery disease, cardiac arrhythmia and heart failure, CardioDx is poised to expand patient access and improve healthcare quality and efficiency through the commercialization of genomic technologies. For more information, please visit

Media Contact: Nicole Osmer