Clinical utility of the acoustic detection of coronary stenosis as an early rule-out criterion: a blinded, prospective, monocentric study versus standard care

Abstract

Abstract Background: The CADScor®System is a noninvasive and radiation-free technology that searches for stenosis induced by turbulent coronary blood flow. A CADSscore represents the acoustic detection results of coronary stenoses. We assessed consecutive patients with stable symptoms without known coronary artery disease (CAD) to define a low risk for obstructive CAD based on a low CAD score than a standard approach of clinical assessment using noninvasive and invasive diagnostic measurements. Methods: Overall, 214 consecutive patients aged ˃40 years in a German cardiological outpatient unit were included. Patients underwent an initial clinical assessment, a double-blinded CAD score, standard examinations, and a national guidance-based diagnostic cascade. They underwent a 6-month telephone follow-up to capture future CAD events. A CAD score of ≤20 was defined as low risk. Results: Overall, 196 patients completed the planned diagnostic workup after their initial visit, and 187 had a valid CAD score. All 196 patients underwent an electrocardiogram (ECG) and echocardiography, and 178 patients underwent a stress ECG. According to the initial standard evaluation, 41 patients were considered to be low-risk without further diagnosis. A CAD score of ≤20 was found in 51 patients. According to clinical standards, 85 and 77 patients underwent noninvasive testing and invasive angiography, respectively. The obstructive CAD was invasively diagnosed in 25 patients, of whom 4 had a CAD score of ≤20. No additional CAD was detected at the 6-month follow-up. Overall, 41 of the 165 noninvasive and invasive diagnostic procedures could have been avoided with a CAD score of ≤20 as the exclusion criterion for further diagnosis after the standard initial diagnosis. Furthermore, 10 of the 52 invasive procedures without evidence of obstructive CAD could have been prevented. Conclusions: The obstructive CAD was confirmed in 12.8% of patients with stable symptoms and suspected CAD. Therefore, advanced noninvasive testing was mainly used for further CAD exclusion. The diagnostic yield of invasive angiography was low, and approximately a quarter of further diagnostic procedures could have been avoided with the CAD score, which showed an acceptable false-negative rate compared with the standard diagnostic tools. Trial registration: Deutsches Register Klinischer Studien (DRKS): DRKS00016986 (22/03/2019)