Abstract 263: The Use of a Blood-Based Age/Sex/Gene Expression Test Helped Define Symptomatic Patients Unlikely to Benefit From Additional Anatomic or Functional Cardiac Testing: A Case Series Analysis in the Outpatient Cardiology Setting

Abstract

Background: More effective tactics are needed to evaluate patients with suspected symptomatic obstructive coronary artery disease (CAD). Results from recent studies such as PROMISE demonstrated that < 10% of these patients had a cardiac cause for their symptoms. A previously validated blood-based test, incorporating age, sex, and gene expression levels, demonstrated a 96% negative predictive value among symptomatic, non-diabetic patients in the evaluation of obstructive CAD at a threshold score of 15 or less, where a low score is indicative of low likelihood of obstructive CAD. Objective: The objective of this retrospective, case-control study (NCT02223286) was to evaluate the use of an age/sex/gene expression score (ASGES) and conventional anatomic and functional testing in the diagnostic work-up of patients referred for assessment of stable symptoms suggestive of obstructive CAD in the cardiologist’s office. Methods: In this post-hoc case series analysis, patients with stable symptoms suggestive of obstructive CAD referred to two cardiologists underwent both ASGES (range 1-40) testing and additional cardiac testing, which included ETT, stress echo, MPI, or CCTA. Demographics and clinical factors as well as ASGES results (predefined as low score/low likelihood of obstructive CAD [ASGES ≤15] or elevated score/elevated likelihood of obstructive CAD [ASGES >15]) and other cardiac test results were collected. Results: Among 67 patients in this analysis, the mean age was 52 years, 60% of the patients were female, 30% were smokers, 54% had hypertension, and 60% had dyslipidemia. The mean ASGES score was 13, and 63% (42/67) of the patients had an ASGES ≤15 (low score). Upon additional cardiac testing, 0% (0/42) of patients with a low score as compared to 20% (5/25) of patients with an elevated score had at least one abnormal anatomical or functional cardiac test result (p<0.01). Conclusion: In this case series analysis, utilization of additional cardiac testing in low ASGES patients did not add new information for further clinical-decision making. Based on these findings, a strategy of using the ASGES test early in the diagnostic process may lead to a reduction of further cardiac testing among low ASGES patients who have a low likelihood of obstructive CAD.