Magnetic Resonance Angiography to Diagnose Atherosclerotic Disease

Magnetic Resonance Angiography (MRA) is a developing technique that permits the non-invasive
evaluation of arterial and venous structures without the need for x-ray based catheter
angiography. While dramatic progress has been made in the last few years, there are still
substantial limitations in the accuracy of MRA in the evaluation of coronary artery. The
primary aim of this study is to evaluate state-of-the-art techniques for coronary MRA in
subjects with known or suspected coronary atherosclerosis. The secondary aim of this protocol
is to generate natural history data for future hypothesis-driven clinical trials using MRA
techniques developed in this current protocol. The long-term objective of this pilot study
and research initiative is to improve coronary MRA to the point that it can reliably replace
diagnostic x-ray catheter angiography in the evaluation of subjects with atherosclerotic
disease.

- INCLUSION CRITERIA:

1. Subjects with known or suspected atherosclerotic disease based on clinical
findings or documented by angiography (conventional, CT or MRA), or Doppler
ultrasound. Subjects at risk for atherosclerosis including: smoking,
hyperlipidemia, low levels of high density lipoproteins (less than 50 mg/dl for
women and less than 40 mg/dl for men), hypertension, family history (early onset
atherosclerosis less than 55 year old in male and less than 65 year old in female
who is first degree relative), and diabetes mellitus or metabolic syndrome.

2. Subject must be willing to participate in the protocol.

3. Subject age greater than 18 years old.

4. Subject must be clinically stable and be able to come to the Clinical Center to
participate in the study.

EXCLUSION CRITERIA:

1. Subjects with contraindication to MRI scanning. These contraindications include but
are not limited to the following devices or conditions:

1. Implanted cardiac pacemaker or defibrillator

2. Cochlear Implants

3. Ocular foreign body (e.g. metal shavings)

4. Embedded shrapnel fragments

5. Central nervous system aneurysm clips

6. Implanted neural stimulator

7. Medical infusion pumps

8. Any implanted device that is incompatible with MRI.

2. Unsatisfactory performance status as judged by the referring physician such that the
subject could not tolerate an MRI scan. Examples of medical conditions that would not
be accepted would include unstable angina and dyspnea at rest.

3. Subjects requiring sedation for MRI studies.

4. Subjects with a condition precluding entry into the scanner (e.g. morbid obesity,
claustrophobia, etc.).

5. Pregnant or lactating women.

6. Subjects with severe back-pain or motion disorders who will be unable to tolerate
supine positioning within the MRI scanner and hold still for the duration of the
examination.

7. Subjects who are unable to undergo a CTA within 1 month of the MRA part of this study,
or are unable undergo or be scheduled for a cardiac catheterization within 1 month of
the MRA.

FOR GADOLINIUM BASED MRI STUDIES ONLY:

8. History of severe allergic reaction to gadolinium contrast agents despite the use of
premeditation with an anti-histaminic and cortisone.

9. Creatinine value greater than 3.0 mg/dl

FOR CARDIAC CT:

10. Recent cardiac CT within a month. Both a coronary CTA and calcium score scan are
required for this study. If any of these scans were performed at an outside facility
and meet the necessary quality level, then that aspect of the cardiac CT scan
(coronary CTA, calcium score scan or both) will not be performed at the NIH. Coronary
CTA and/or calcium score CT obtained at the outside facility must be performed within
one month of subject inclusion and acquired using a 16 slice scanner or higher and
should be of good quality. The unformatted images of outside cardiac scans must be
available to the primary investigator within one month of their acquisition for
eligibility of inclusion in the study.

FOR CORONARY CTA:

11. Contraindication to the use of CT contrast agents:

1. Creatinine value greater than 1.4 mg/dl

2. History of multiple myeloma

3. Use of metformin-containing products less than 24 hrs prior to contrast
administration

4. History of significant allergic reaction to CT contrast agents despite the use of
premeditation with an anti-histaminic and cortisone.

12. Subjects with contraindication precluding the use of beta blockers necessary to
perform the coronary CTA. These include:

1. Asthma

2. Active bronchospasm

3. Moderate or severe COPD

4. Second or third degree AV block

5. Decompensated cardiac failure

6. Allergy to beta blockers

7. Systolic blood pressure less than 100 mm Hg

8. Pregnancy or nursing