Functional Assessment of Coronary Artery Disease by CTA Flow Encoding

The purpose of this pilot study is to test the ability of Transluminal Flow Encoding (TAFE)
to evaluate vessel specific ischemia in patients with a clinical indication for invasive
coronary angiography (ICA) with fractional flow reserve (FFR) measurements for suspected
coronary disease. TAFE is a novel method that derives coronary blood flow from easily
obtainable non-invasive coronary CT angiograms.

Participants will undergo a rest coronary CTA, a regadenoson stress CT, and a clinically
indicated invasive coronary angiogram. The study aims to determine the accuracy of TAFE
compared to invasive fractional flow reserve.

We hypothesize that TAFE-derived coronary blood flow, coronary flow reserve, and myocardial
CT perfusion imaging can accurately diagnose an abnormal FFR (<0.80) measured in vessels in
patients undergoing invasive coronary angiography.

Inclusion Criteria:

- Inclusion Criteria A. Male or female patients, age 40 years and older. Women of child
bearing potential must demonstrate a negative pregnancy test within 24 hours of the
study CT.

B. Referral for invasive coronary angiography for a suspicion of coronary artery disease
with possible percutaneous intervention planned.

C. Able to understand and willing to sign the Informed Consent Form.

Exclusion Criteria:

A. Patients with a known history of coronary artery bypass surgery. B. Current or previous
ST elevation myocardial infarction (MI), prior MI (confirmed by persistent pathologic Q
waves on ECG, clinical reports of CPK-MB or Troponin > three times the upper limit of
normal or a fixed perfusion defect on nuclear imaging) C. Current evidence of acute
myocardial ischemia, unstable angina, or cardiovascular instability including troponin >
than the limit of detection (≥0.06 ng/ml), new ST depression > 1 mm, hypotension with a
systolic pressure <90 mm Hg.

D. Known allergy to iodinated contrast media

E. Known or suspected intolerance or contraindication to beta-blockers including:

1. Known allergy to beta-blockers

2. History of moderate to severe bronchospastic lung disease (including moderate to
severe asthma) F. Known allergy to regadenoson or aminophylline. G. Any patient not
deemed medically stable by a physician. F. Known or suspected severe symptomatic
aortic stenosis. G. Severe hypertrophic obstructive cardiomyopathy. H. Evidence of
severe symptomatic heart failure (NYHA Class III or IV) at the time of the scan.

I. Inability to lie flat. J. Atrial fibrillation or uncontrolled tachyarrhythmia, or
advanced atrioventricular block (second or third degree heart block) K. Elevated serum
creatinine (> 1.5mg/dl) OR calculated creatinine clearance of < 60 ml/min (using the
Cockcroft-Gault formula) L. History of contrast-induced nephropathy M. Severe pulmonary
disease or other disorder that does not allow patient to hold breath for 10 seconds or
more.

N. History of organ transplantation O. Acute myocarditis or pericarditis. P. Recent history
of illicit drug use (past 3 months) Q. Recent use of dipyridamole containing medications.
R. Current pregnancy.