IMPACT-PCP Data Support CardioDx's Corus CAD to Evaluate Symptomatic Patients

May 17, 2013—CardioDx, Inc. (Palo Alto, CA) announced results of a clinical utility study of the Corus CAD gene expression test in the real-world primary care setting for evaluating patients with signs and symptoms suggestive of obstructive coronary artery disease (CAD). Results from the multicenter, prospective IMPACT-PCP (Investigation of a Molecular Personalized Coronary Gene Expression Test on Primary Care Practice Pattern) trial was presented at the American Heart Association's QCOR 2013: Quality of Care and Outcomes Research scientific sessions, held on May 15–17 in Baltimore, Maryland.

According to CardioDx's announcement, the study showed that clinicians' diagnostic decision making was significantly influenced by integrating Corus CAD early to assess patients for obstructive CAD. Patients presenting with typical and atypical presentations of chest pain (n = 251) were enrolled in the study and evaluated by nine primary care clinicians in four practices for assessment of symptoms. The clinician's diagnostic strategy was evaluated before and after the Corus CAD results were known.

After Corus CAD testing, clinicians modified their diagnostic strategy in 58% of patients (P < .001). Among the 127 patients with low Corus CAD scores (≤ 15), 60% (76/127) saw a reduction in testing and only 2% (3/127) had increased testing. Patient follow-up is ongoing, with 98% of patients having completed 30-day follow-up. Results of the study suggest that early use of Corus CAD in primary care practices to assess obstructive CAD influences clinical decision making, reported CardioDx.

“Primary care offices get approximately 10,000 visits a day from patients with symptoms of chest pain,” commented lead investigator Lee Herman, MD, in the company's press release. “Evaluation of patients with typical or atypical symptoms suggestive of CAD costs billions of dollars in annual cardiac-related diagnostic expenses in the United States. Clearly, we need better noninvasive diagnostic tests to quickly and accurately assess patients for obstructive CAD in the primary care setting. With a high negative predictive value of 96% and a high sensitivity of 89%, Corus CAD is a convenient and reliable diagnostic test that can help primary care clinicians accurately exclude the diagnosis of obstructive CAD early in the assessment pathway and can help identify whether or not patients need further cardiac testing.”

As stated in the company's press release, the CardioDx Corus CAD is a clinically validated blood-based test for the assessment of obstructive CAD. The test involves a routine blood draw administered in the clinician's office and does not expose patients to risks of radiation or imaging agent intolerance. It is a gender-specific test that accounts for critical biological differences between men and women.

The Corus CAD test is intended for use in nondiabetic stable patients who present with typical or atypical symptoms suggestive of CAD, have no known history of CAD and no previous myocardial infarction or revascularization procedure, and are not currently taking steroids, immunosuppressive agents or chemotherapeutic agents.

The company advised that the Corus CAD test has been clinically validated in multiple independent patient cohorts, including two prospective, multicenter PREDICT and COMPASS studies in the United States. In the COMPASS study, Corus CAD outperformed myocardial perfusion imaging in diagnostic accuracy, sensitivity (89% vs 27%; P < .001), and negative predictive value (96% vs 88%; P < .001). The Corus CAD system also demonstrated excellent performance for excluding obstructive CAD relative to both invasive angiography and computed tomography angiography. Additionally, a retrospective, multicenter chart review study and the prospective IMPACT CARD trial at Vanderbilt University, the first of two prospective clinical utility studies, demonstrated that Corus CAD use yields statistically significant and clinically relevant changes in patient management decisions in both primary care and cardiology settings, stated CardioDx.