The Use Of A Precision Medicine Blood Test In A Rural Setting May Reduce The Need For Unnecessary Patient Travel To Undergo Advanced Cardiac Testing

Introduction: Patients in the rural setting have been shown to have less access to specialist care. More effective tactics are needed to evaluate symptomatic patients with suspected obstructive coronary artery disease (CAD) in this setting. A blood-based age/sex/gene expression score (ASGES) incorporating key features of precision medicine has shown clinical validity with a 96% negative predictive value and 89% sensitivity in estimating a symptomatic patient’s current likelihood of obstructive CAD. Objective: The objective of this retrospective study was to evaluate the use of an ASGES and its effects on unnecessary testing and patient travel burden for rural patients with suspected ischemic heart disease. Methods: Medical records of 112 symptomatic patients with no previous advanced cardiac testing were analyzed at a single, rural-based cardiology clinic from 2014 to 2016. Demographics, clinical characteristics, and ASGES (predefined as low < 15 and elevated > 15) results, as well as follow-up for major adverse cardiac events (MACE) and coronary artery revascularizations were collected for analysis (median follow-up of 389 days). Mileage is calculated as the cumulative distance from a patient’s zip code to the care center using Google map. Patients who had concomitant diagnoses outside of intended use were excluded. Results: Among 112 patients, 58 (52%) had a low score of ≤15, with an average ASGES of 7 (interquartile range 3.5 -11). Of the 58 patients with low scores, the average age was 59 (±13), 54 (93%) were women, 47 (81%) were white, and 49 (84%) had typical angina symptoms. With respect to a decrease in travel burden, the majority of low score patients (59%) made more than one trip following the initial workup, traveling a median of 325 miles. Among the 112 patients, MACE/revascularization was found in 2 patients (2 events) with low ASGES compared to 4 patients (9 events) in the elevated ASGES group. Conclusions: This study highlights the potential utility of a simple blood test in the rural setting to rule out obstructive CAD and avoid unnecessary travel burden for advanced cardiac testing. Almost half of the eligible patients had a low score and were at low current likelihood for obstructive CAD, thus they were unlikely to benefit from further testing.