Background:

- This study is designed for people who need a standard, non-research invasive coronary angiogram to find out if they have heart disease. Researchers want to take a computed tomography (CT) scan of people s hearts before their procedure to see if this less invasive test can also diagnose coronary artery disease.

Objectives:

- To learn if a new way to view CT pictures is able to accurately diagnose coronary artery disease.

Eligibility:

- People age 55 and older who need a coronary angiogram.

Design:

• Participants will be screened with their medical records.
• Participants may give a blood sample.
• Participants may have a CT scan of the heart with and without contrast. The CT scan will not interfere with their medical care.
• Participants blood pressure and heart rhythm will be monitored before, during, and after the CT scan. They may have an electrocardiogram.
• Before the scan, participants will have an intravenous catheter put into their arm. It will be used to inject contrast.
• Participants may take a beta blocker to slow their heart rate.
• Participants may take nitroglycerin under their tongue. It will enlarge their heart blood vessels and improve picture quality. It may cause a flushing sensation or headache.
• Participants will lie on their back on a padded table. The table slides into a large, donut-shaped machine. An x-ray tube will move around their body, taking pictures. They will be asked to hold their breath for 5 seconds at a time.
• Participants will be called 30 days after their angiogram. They will answer questions about their health, hospital visits, or medical treatments.

Coronary calcium can impair the accurate evaluation of the coronary arteries with coronary computed tomography angiography (CCTA). A novel approach to potentially overcome this limitation is coronary calcium subtraction, where areas of calcification identified on a non-contrast scan are removed from the contrast enhanced images.

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• INCLUSION CRITERIA:

  1. Age over 55 years
  2. Subjects referred for coronary angiography
  3. Able to understand and willing to sign the Informed Consent Form

EXCLUSION CRITERIA:

1. Known allergy to iodinated contrast media
2. Estimated GFR less than 50 ml/min
3. Atrial fibrillation or other continuous cardiac arrhythmias
4. Known or suspected intolerance or contraindication to beta-blocker medication (i.e. significant reactive airway disease, decompensated heart failure, Mobitz type 2 second degree or 3rd degree atrio-ventricular heart block)
5. Inability to adequately hold breath for 5 seconds
6. Pregnancy. Women of child bearing potential must demonstrate a negative pregnancy test within 24 hours of the study MDCT.