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Corus CAD Clinical Utility

In addition to clinical validity, it is also important to demonstrate that a test can change and improve clinical care. These types of studies are often referred to as clinical utility studies. Clinical utility studies for Corus CAD have demonstrated that the test changes clinician decision-making in clinically relevant ways. In both the primary care and cardiology settings, clinicians reduced referral rates to cardiology and/or advanced cardiac testing for symptomatic patients with low (≤15) Corus CAD scores.

IMPACT-CARD
IMPACT-PCP
REGISTRY I
WOMEN

The IMPACT-CARD (Investigation of a Molecular Personalized Coronary Gene Expression Test on Cardiology Practice Pattern) Trial

Purpose:

To measure the impact of the Corus CAD score on clinicians' care plans for patients presenting with chest pain or angina equivalent symptoms in the cardiology office.

Type:

Prospective

Size:

83 patients were eligible for analysis in the trial and matched with 83 historical controls with similar clinical factors.

Trial Design:

IMPACT-CARD1 was conducted in the cardiology department at Vanderbilt University Medical Center using a pre- and post-trial design. The clinicians performed their initial assessment of the patient and recorded their preliminary patient management plan into one of the following categories: (1) no intervention/medical management; (2) referral for coronary computed tomography angiography (CCTA) or stress testing with or without imaging, including myocardial perfusion imaging (MPI); or (3) referral for invasive coronary angiography. The clinicians then obtained a peripheral blood sample and ordered the Corus CAD test. After receiving the Corus CAD results, each clinician decided on the appropriate evaluation and management of the patient using the Corus CAD score in conjunction with the information that was previously available. We measured both the percentage of time that clinicians changed their care plans and whether the change resulted in an increase or decrease in the intensity of testing.

Key Findings:

Clinicians changed their care plan for 58% of the patients (48/83). There was an overall reduction in the intensity of testing across the patient population after clinicians received the Corus CAD scores. Low Corus CAD scores generally corresponded with less intensive cardiac diagnostic evaluation and management, while elevated scores generally corresponded with more intensive cardiac diagnostic evaluation and management.

Status:

Published, Critical Pathways in Cardiology (May 2013)1

Identifier:

NCT01251302

 

IMPACT-CARD Trial Results (n=83)

Clinicians Changed Patients' Care Plan 58% of the Time After Corus CAD Testing (p<0.001)

 

Patients With Downgraded Testing

Patients With No Change in Testing

Patients With Upgraded Testing

Corus CAD (≤15)

56%

(29/52)

44%

(23/52)

0%

(0/52)

Corus CAD (>15)

10%

(3/31)

39%

(12/31)

52%

(16/31)


  1. McPherson JA, Davis K, Yau M, et al. The Clinical Utility of Gene Expression Testing on the Diagnostic Evaluation of Patients Presenting to the Cardiologist With Symptoms of Suspected Obstructive Coronary Artery Disease: Results From the IMPACT (Investigation of a Molecular Personalized Coronary Gene Expression Test on Cardiology Practice Pattern) Trial. Crit Pathw Cardiol. 2013;12(2):37-42.

The IMPACT-PCP (Investigation of a Molecular Personalized Coronary Gene Expression Test on Primary Care Practice Pattern) Trial

Purpose:

To measure the impact of the Corus CAD score on clinicians' care plans for patients presenting with chest pain or angina equivalent symptoms in the primary care setting.

Type:

Prospective

Size:

251 patients eligible for analysis.

Trial Design:

IMPACT-PCP1 was conducted by eight primary care clinicians from four U.S. practices using a pre- and post-trial design. The clinicians performed their initial assessment of the patient and recorded their preliminary patient management plan into one of the following categories: (1) no further cardiac testing or treatment; (2) medical management or lifestyle changes; (3) referral for coronary computed tomography angiography (CCTA) or stress testing with or without imaging, including myocardial perfusion imaging (MPI); or (4) referral for invasive coronary angiography. The clinicians then obtained a peripheral blood sample and ordered the Corus CAD test. After receiving the Corus CAD results, each clinician then decided on the appropriate evaluation and management of the patient using the Corus CAD score in conjunction with the information that was previously available. We measured both the percentage of time that clinicians changed their care plans and whether the change resulted in an increase or decrease in the intensity of testing.

Key Findings:

Clinicians changed their care plans for 58% of the patients (145/251). There was an overall reduction in testing across the patient population after clinicians received the Corus CAD scores. Low Corus CAD scores (≤15) generally corresponded with less intensive cardiac diagnostic evaluation or more intensive management, while elevated scores (>15) generally corresponded with no change in cardiac diagnostic evaluation or more intensive management.

Status:

Published, Journal of the American Board of Family Medicine (March 2014)1

Identifier:

NCT01594411

 

IMPACT-PCP Trial Results (n=251)

Clinicians Changed Patients' Care Plan 58% of the Time After Corus CAD Testing (p<0.001)

 

Patients With Downgraded Testing

Patients With No Change in Testing

Patients With Upgraded Testing

Corus CAD (≤15)

60%

(76/127)

38%

(48/127)

2%

(3/127)

Corus CAD (>15)

14%

(17/124)

47%

(58/124)

39%

(49/124)


  1. Herman L, Froelich J, Kanelos D, et al. Utility of a Genomic-based, Personalized Medicine Test in Patients Presenting With Symptoms Suggesting Coronary Artery Disease. J Am Board Fam Med. 2014;27(2):258-67.

REGISTRY I

Purpose:

To determine the impact of Corus CAD testing on primary care decision making around further cardiac testing.

Type:

Prospective

Size:

342 stable, non-acute patients in seven community-based primary care practices.

Key Findings:

Registry I1 found a strong association between cardiac referral rates by low (≤15) and elevated (>15) Corus CAD score groups, with only 6% (10/167) of the low Corus CAD score patients versus 70% (122/175) of the elevated Corus CAD score patients being referred for further cardiac evaluation (p<.0001). Approximately 49% of patients had a low Corus CAD score, allowing their primary care providers to focus on other causes for their symptoms. Each 10-point decrease in a patient's Corus CAD score was associated with a 14-fold decreased odds of referral for further cardiac evaluation or testing (p<.0001). In addition, patients with a low Corus CAD score had a 94% reduced odds of referral relative to patients with an elevated Corus CAD score (p<.0001).

Status:

Published, American Journal of Medical Quality (May 2014)1

Identifier:

NCT01557855


  1. Ladapo JA, Lyons H, Yau M, et al. Enhanced Assessment of Chest Pain and Related Symptoms in the Primary Care Setting Through the Use of a Novel Personalized Medicine Genomic Test: Results From a Prospective Registry Study. Am J Med Qual. 2014 May 5. [Epub ahead of print]

Aggregate Analysis of the Two Studies of Clinical Utility in Women

Purpose:

To observe if the age/sex/gene expression test (Corus CAD test) results are incorporated into medical decision making to help identify women whose symptoms are not due to obstructive CAD.

Type:

Review of aggregated data of two prospective studies

Size:

Data were pooled from 16 primary care providers (PCPs) in geographically diverse U.S. sites on 320 women presenting with stable symptoms suggestive of obstructive CAD and undergoing Corus CAD testing.1

Trial Design:

This clinical utility analysis was an aggregated analysis of female cohorts from the IMPACT-PCP (NCT01594411) and REGISTRY I (NCT01557855) studies. The eligibility criteria were the same in both studies: stable, non-acute, participants without diabetes presenting to PCPs in the outpatient setting with typical or atypical symptoms suggestive of obstructive CAD. Data variables merged from the two datasets included Corus CAD score, sex, age, race/ethnicity, smoking status, blood pressure, and Corus CAD-directed care referral patterns.

Primary care clinicians were allowed to incorporate the Corus CAD test results, at their own discretion, as part of their medical decision-making processes and in conjunction with other clinical information. The primary outcome of this analysis was the association between Corus CAD scores and referrals for further cardiac evaluation (referral to cardiology or advanced cardiac testing). Participants were followed for safety after the diagnostic workup in both clinical utility studies.

Key Findings:

The referral rate for further cardiac evaluation was 4.0% (10/248) for women with low Corus CAD scores versus 83.3% (60/72) for women with elevated Corus CAD scores (OR=0.008, p value <0.0001). The overall MACE/revascularization rate on median follow-up was 1.2%.* After adjusting for clinical covariates, women with low Corus CAD scores were significantly less likely to be referred for further cardiac evaluation (OR=0.013, p <0.0001).

Status:

Published, Menopause. 2015 Apr 6 [Epub ahead of print]

Identifier:

N/A

 

Aggregated Analysis: Subgroup of Women in Two Clinical Utility Studies (n=320)

 

Not Referred (%)

Referred (%)

 

Corus CAD (≤15)
N=248, 78%

238 (96%)

10 (4%)

OR = 0.008
p-value <0.0001

Corus CAD (>15)
N=72, 22%

12 (17%)

60 (83%)

 

Study

Safety: # Events

IMPACT-PCP

1
(30 days, event not related)

REGISTRY I

3
(avg. 264 days, 1 event not related)


* Median follow-up period for IMPACT-PCP = 37 days, REGISTRY I = 278 days

  1. Ladapo JA, Herman L, Weiner BH, et al. Use of a Blood Test Incorporating Age, Sex, and Gene Expression Influences Medical Decision-making in the Evaluation of Women Presenting with Symptoms Suggestive of Obstructive Coronary Artery Disease: Summary Results from Two Ambulatory Care Studies in Primary Care. Menopause. 2015 Apr 6. [Epub ahead of print] PubMed PMID: 25828395.