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The PREDICT (Personalized Risk Evaluation and Diagnosis In the Coronary Tree) Study


To develop and validate the Corus CAD test.




Over 4,000 samples collected from 39 sites in the U.S. The algorithm development and validation phases used 640 and 526 samples, respectively.

Study Design:

PREDICT1 enrolled patients who had been referred for invasive coronary angiography by their physician. Patients had a blood sample drawn just prior to their catheterization procedure. CardioDx received the angiography results from the catheterization procedure, including the clinician's assessment of the maximum percent stenosis, or level of CAD, in any of the major coronary arteries as well as clinical data. In addition to the local assessment of the extent of disease, each angiography used in the study was sent to a single third-party core lab for Quantitative Coronary Angiography, or QCA, to provide a second and independent assessment of the level of obstructive coronary artery disease*. A case was defined as any patient that had at least one lesion greater or equal to 50% stenosis by QCA, and a control was any patient with no lesions greater or equal to 50% stenosis. We compared the ability of the algorithm score to classify patients as to their case and control status from angiography and assessed whether the algorithm score had higher diagnostic performance than clinical factors alone.

Key Findings:

The PREDICT study demonstrated that the Corus CAD algorithm significantly classifies patients as to their obstructive CAD status and has a sensitivity of 85% and negative predictive value (NPV) of 83% at a score threshold of less than or equal to 14.75 in a population of men and women referred to the catheterization lab.


Published, Annals of Internal Medicine (October 2010)2



* In the PREDICT Study, 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.

  1. PREDICT study. Clinical trial summary found at:, NCT00500617.
  2. Rosenberg S, Elashoff MR, Beineke P, et al. Multicenter Validation of the Diagnostic Accuracy of a Blood-Based Gene Expression Test for Assessing Obstructive Coronary Artery Disease in Nondiabetic Patients. Ann Intern Med. 2010;153:425-434.