PREDICT Trial

Based on the results described in Wingrove et al. (2008)1 the prospective, multi-center PREDICT (Personalized Risk Evaluation and Diagnosis In the Coronary Tree)2 trial was designed and enrolled to develop and validate a gene expression test for assessing the likelihood of obstructive* coronary artery disease (CAD) in stable patients with symptoms suggestive of CAD. Eric Topol, M.D., Director of the Scripps Translational Science Institute in La Jolla, California, is the principal investigator of this trial. Patient enrollment in PREDICT was completed in January of 2011, with more than 4,000 patients in total.

Results from experiments reported in Elashoff et al., BMC Medical Genomics, 2011, showed that diabetic and nondiabetic patients had distinct patterns of changes in gene expression in the presence or absence of CAD. Thus, algorithm development of Corus® CAD was limited to nondiabetics.

1,343 nondiabetic patients from 39 PREDICT clinical sites, enrolled between July 2007 and April 2009, were included in the development and prospective validation of Corus CAD. All patients had been referred for elective invasive coronary angiography. The patients were classified as cases or controls based on whether or not they had obstructive CAD, as determined by quantitative coronary angiography (QCA). Blood samples were also collected from the patients, and data from the QCA analysis was then compared to Corus CAD test results to determine test performance. Both QCA technicians and clinical data analysts were blinded to patient disease status.

PREDICT Trial Design

PREDICT Validation Study Findings

Majority of Patients Sent for Invasive Angiography Did Not Have Obstructive CAD

  • Only 37% of all patients in PREDICT were found to have obstructive CAD by QCA
    • The rate of obstructive CAD was particularly low in women (26%)
  • These findings from the PREDICT trial are consistent with those reported by Patel et al. in a study of 398,978 patients published in the New England Journal of Medicine in 20102

Test Has High Sensitivity and Negative Predictive Value

  • Test sensitivity and negative predictive value are 85% and 83%, respectively.

Test Score Reflects Presence and Extent of Obstructive CAD

  • A higher test score corresponds to a higher likelihood of obstructive CAD. (See Figure 1.)
  • Test score is significantly correlated with overall coronary atherosclerotic disease burden. (See Figure 2.)

Test Improves Classification of Patient Disease Status

  • The combination of test score and clinical factor assessment is significantly better than clinical factor assessment alone. (See Figure 3.)
  • Independent of myocardial perfusion imaging result or clinical risk, increasing test score leads to increasing likelihood of obstructive CAD.

Figure 1

Figure 2

Figure 3

* 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 (QCA).

  1. Wingrove JA et al. Correlation of peripheral-blood gene expression with the extent of coronary artery stenosis. Circ Cardiovasc Genet. 2008; 1:31-38
  2. PREDICT trial. Clinical trial summary found at: www.clinicaltrials.gov, NCT00500617.
  3. Rosenberg S 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.
  4. Patel MR et al. Low diagnostic yield of elective coronary angiography. N Engl J Med. 2010;362(10):886-895.
  5. Elashoff MR et al.  Development of a blood-based gene expression algorithm for assessment of obstructive coronary artery disease in nondiabetic patients.  BMC Medical Genomics. 2011; 4-26.
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