Prospective International Study of Coronary Subtraction Using 320 Detector Row CT (CorSub)

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.