Pre-test probability estimation of coronary artery disease can be improved by adding an acoustic-based risk score.

Background: The American Heart Association/American College of Cardiology (AHA/ACC) 2021 Chest Pain Guidelines introduced a new pre-test probability (PTP) model for obstructive coronary artery disease (CAD). The model recommends a 15 % risk cut-off for referral for further testing. Whether addition of a risk score measured from acoustic detection of coronary turbulence obtained by the noninvasive device CADScor®System (CAD-score) improves the AHA/ACC-PTP capability to assign the correct risk category has not been tested. Methods: Patients with symptoms suggestive of CAD referred for coronary CT angiography and undergoing a same-day CAD-score were included. PTP was calculated based on sex, age, and symptoms. All patients with suspected stenosis on CT angiography were referred for invasive angiography. A CAD-score ≤ 20 was used as cut-off for low likelihood of CAD. Results: The study population consisted of 2874 patients (47 % women, median age [IQR] 58 [52-65] years). PTP categorized 2044 (71 %) of patients as > 15 % amongst whom 387 (18.9 %) were re-classified to low likelihood by a CAD-score ≤ 20. In patients aged < 70 without hypertension, 37 % were re-classified to low probability. Of the 830 patients with low PTP ≤ 15 %, 68.7 % had a CAD-score ≤ 20 indicating a deferred testing strategy. Conclusion: Adding an acoustic-based CAD-score to the PTP in patients with AHA/ACC defined-PTP > 15 % risk can reduce the number of diagnostic tests by overall 19 %, and 37 % in subgroups, and may support cost-effective clinical decision-making. Moreover, CAD-score may aid risk stratification in patients, particularly with AHA/ACC-PTP ≤ 15 %.