A Study of Computed Tomography (CT) for Evaluation of Coronary Artery Blockages in Typical or Atypical Chest Pain

Inclusion Criteria: * The subject has typical or atypical chest pain suspected of CAD and is referred for an elective coronary angiography. * The subject must be scheduled to undergo a CATH procedure between 48 hours and 3 weeks post CCTA procedure. * The subject must not undergo any cardiac interventional treatment between the 2 procedures. * The subject must have sinus rhythm with stable heart rate of ≤65 beats per minute (bpm) or if heart rate was \>65 bpm, the subject must agree to the use of beta-blocker(s) prior to the CT scan procedure to achieve stable heart rate of ≤65 bpm. Exclusion Criteria: * The subject had an established diagnosis of CAD by a) previous CATH, b) prior myocardial infarction confirmed by ECG, or c) prior revascularization (balloon angioplasty, stent placement, or CABG). * The subject had a known allergy to iodinated contrast agent, including but not limited to hives, anaphylactoid or cardiovascular reactions, laryngeal edema and bronchospasm. * The subject had impaired renal function with a serum creatinine level of 1.7 mg/dL (150 μmol/L) or above. * The subject had atrial fibrillation/flutter or any irregular heart rhythm considered by the investigator to interfere with temporal acquisition of cardiac CT images. * The subject had a resting heart rate of \>100 bpm and/or a resting systolic blood pressure of \<100mm Hg. * The subject had an artificial heart valve(s). * The subject has had prior pacemaker or internal defibrillator lead implantation. * The subject's resting heart rate was \>65 bpm and beta-blocker therapy was contraindicated. * The subject had a contraindication to verapamil when beta-blocker therapy could not be administered. The subject had a contraindication to nitroglycerin. * The subject had evidence of ongoing or active clinical instability.