To demonstrate the incremental utility of SSF for individuals undergoing CCTA, with expected improvements in image quality and diagnostic accuracy.

Hypothesis: Coronary CT angiography (CCTA) employing a novel intracycle motion compensation algorithm (SnapShot Freeze [SSF]) will be superior to CCTA without an intracycle motion compensation algorithm ("conventional" CCTA) for diagnostic accuracy and image quality.

Scientific Basis: Preliminary study (Leipsic, Min, Journal of Cardiovascular Computed Tomography [in press]) of coronary CT angiograms in individuals undergoing pre-procedural assessment for transcatheter aortic valve replacement (n=36) demonstrate improved image quality of CCTA using SSF compared to CCTA not using SSF. Importantly, individuals in this study did not receive heart rate slowing agents (e.g., beta blockers), and diagnostic image quality was substantially improved. While not statistically powered on a per-patient basis, per-segment diagnostic accuracy of CCTA using SSF was superior to conventional CCTA. These results are complementary to those derived from internal testing at GE Healthcare wherein phantom work has demonstrated improved diagnostic performance using SSF compared to conventional image acquisitions.

Long-term Goal/Purpose: To demonstrate the incremental utility of SSF for individuals undergoing CCTA, with expected improvements in image quality and diagnostic accuracy. If the aims of this study are achieved, the use of SSF for effective temporal resolution improvement may obviate (or reduce) the need for CT hardware for improved temporal resolution.

Inclusion Criteria:

1. Consenting adult patients ≥18 years of age;
2. Suspected but without known prior history of CAD
3. Not actively taking heart rate lowering agents at least 48 hours prior to study (e.g., AV nodal blockers such as beta blockers, calcium channel blockers or digoxin)
4. Glomerular filtration rate >60 ml/min
5. CCTA and ICA within 1 week of each other with no interscan event (e.g., myocardial infarction or coronary revascularization)

Exclusion Criteria:

1. Incomplete ICA or CCTA;
2. Known CAD (prior myocardial infarction, PCI, CABG)
3. Atrial Fibrillation
4. Abnormal Renal Function (GFR <60 ml/min)
5. Unwilling or unable to give consent
6. Non-cardiac illness with life expectancy <1 year
7. Concomitant participation in another clinical trial in which subject is subject to investigational drug or device
8. Pregnant women
9. Allergy to iodinated contrast agent
10. Contraindications to nitroglycerin
11. Systolic blood pressure ≤90 mm Hg
12. Contraindications to β blockers or nitroglycerin

Consenting adult patients ≥18 years of age, Suspected but without known prior history of CAD, Not actively taking heart rate lowering agents at least 48 hours prior to study (e.g., AV nodal blockers such as beta blockers, calcium channel blockers or digoxin)