Coronary artery disease (CAD) causes one in seven deaths among Americans, and diagnosis can be challenging. To provide the most appropriate care pathways, helpful and convenient testing modalities need to be explored. A diagnosis is only as good as the tools used to help make it.
A few considerations:
- Slightly more than one-third of cardiac catheterizations in patients with stable symptoms find obstructive CAD.
- Patient follow-up data suggest that only 10% of patients presenting with stable chest pain to outpatient clinics have a cardiac etiology.
- The recently published PROMISE trial determined the rate of obstructive disease in patients referred for cardiac imaging tests to be just 6%.
These data indicate that CAD, as prevalent as it is, often presents with symptoms so general that an accurate means to rule it out is needed prior to exposing patients to expensive and potentially risky tests. Ideally, clinicians should be able to select patients who truly need cardiac catheterization, which has historically been somewhat difficult. However, medicine and diagnostics are continually evolving and providing new tools to help improve cardiac care.
A relatively new study indicated that a personalized medicine test helped determine the appropriate cardiac care pathway for patients. An age, sex, and gene expression score (ASGES) is determined by a simple blood test, with an easy-to-understand score. On a scale of 1-40, scores of 15 or less provide confidence that the likelihood of obstructive CAD, and thus need for coronary artery revascularization in the near term, is low. For the study, obstructive CAD was defined as at least one atherosclerotic plaque causing 50% or greater luminal diameter stenosis in a major coronary artery (≥1.5 mm lumen diameter) as determined by invasive quantitative coronary angiography or coronary computed tomography angiography (CTA, ≥2.0 mm).
As scores rise above 15, the likelihood of a blockage in the heart arteries or clinical events increases. The PROMISE substudy, published in the American Journal of Medicine, suggested that low ASGES scores provide the same confidence in outcomes as a normal or negative myocardial perfusion imaging or CTA finding.
Better recognition among clinicians of the ASGES blood test and adoption of the test into clinical practice can save patients from unnecessary and potentially risky procedures. Use of the test can also reduce high medical costs for patients and the healthcare system.