The purpose of the study is to collect acoustic, ECG, and clinical data from consenting participants, so that AusculSciences can perform analysis on the sounds produced by the heart and determine the accuracy of the CAD-det System for detecting CAD.

This is a prospective multi-center clinical trial. Using the CAD-det, acoustic and electrical cardiac data will be collected from participants with intermediate pretest probability of CAD who are referred to invasive coronary angiography (ICA). The CAD-det recording will be administered prior to the scheduled ICA procedure. The data collected by CAD-det will be processed using AusculSciences' Data Analysis Application (DAA) to produce a patient's indication for CAD.

Inclusion Criteria:

1. Stable
2. >/= 19 years old
3. Suspected obstructive CAD
4. Referred to ICA

Exclusion Criteria:

1. Documented CAD or coronary revascularization
2. Age < 19 years old
3. Acute coronary syndromes
4. Congenital heart disease or heart transplantation
5. Dextrocardia
6. Uncontrolled irregular heart rhythm (atrial arrhythmia (fibrillation, flutter) or frequent PACs or PVCs (>10/minute))
7. Resting heart rate > 110 bpm
8. Known hemodynamically-significant valvular heart disease, audible diastolic murmurs, or hypertrophic or non-ischemic cardiomyopathy
9. Chest wall deformity or wounds in adhesive application areas
10. Pregnancy
11. Unwillingness or inability to provide informed consent or to comply with the study protocol