Comprehensive Magnetic Resonance of Peripheral Arterial Disease

• Plaque Volume [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  SFA plaque volume
• Perfusion Index [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  Perfusion index is a MRI measure of calf muscle perfusion indexed to the arterial input. The value is between 0 and 1 with 0 being worst and 1 being best.
• Phosphocreatine Recovery Time Constant - the Time it Takes for Phosphocreatine Levels to Recover to Plateau. [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  Phosphocreatine recovery time constant is the time it takes for phosphocreatine levels to recover to plateau after the completion of exercise. This ranges from 20 to 1000 seconds. 20-40 seconds is normal and any value over 40 seconds is abnormal.

• Low Density Lipoprotein Cholesterol [ Time Frame: 2 years ] [ Designated as safety issue: No ]
• Total Cholesterol [ Time Frame: 2 years ] [ Designated as safety issue: No ]
• High Density Lipoprotein Cholesterol [ Time Frame: 2 years ] [ Designated as safety issue: No ]
• Triglycerides [ Time Frame: 2 years ] [ Designated as safety issue: No ]
• Magnetic Resonance Angiographic Index [ Time Frame: 2 years ] [ Designated as safety issue: No ]
  MRA index is a measure of angiographic severity of disease. 0 = no disease and 4 is severe disease.
• Log Treadmill Exercise Time [ Time Frame: 2 years ] [ Designated as safety issue: No ]
• 6-minute Walk Distance [ Time Frame: 2 years ] [ Designated as safety issue: No ]
• V02 - Maximal Oxygen Consumption [ Time Frame: 2 years ] [ Designated as safety issue: No ]

The purpose of this study is to develop new ways of imaging fatty blockages in the leg arteries to improve upon techniques used now and to develop new ways of understanding how new treatments may affect the disease.

• Drug: Simvastatin
  40mg each night
  Other Name: Zocor
• Drug: Ezetimibe
  10mg daily
  Other Name: Zetia
• Drug: Simvastatin/Ezetimibe
  40mg/10mg each night
  Other Name: Vytorin

• Experimental: Randomized
  Patients are imaged at baseline and randomized to Simvistatin 40 mg each night or Simvistatin 40mg/Zetia 10mg each night for 2 years
  Interventions:

  • Drug: Simvastatin
  • Drug: Simvastatin/Ezetimibe
• Experimental: Ezetemibe
  Patients are imaged at baseline and treated with ezetimibe 10mg each night for 2 years.
  Intervention: Drug: Ezetimibe

• West AM, Anderson JD, Meyer CH, Epstein FH, Wang H, Hagspiel KD, Berr SS, Harthun NL, DiMaria JM, Hunter JR, Christopher JM, Chew JD, Winberry GB, Kramer CM. The effect of ezetimibe on peripheral arterial atherosclerosis depends upon statin use at baseline. Atherosclerosis. 2011 Sep;218(1):156-62. Epub 2011 Apr 16.
• West AM, Anderson JD, Epstein FH, Meyer CH, Wang H, Hagspiel KD, Berr SS, Harthun NL, Weltman AL, Dimaria JM, Hunter JR, Christopher JM, Kramer CM. Low-density lipoprotein lowering does not improve calf muscle perfusion, energetics, or exercise performance in peripheral arterial disease. J Am Coll Cardiol. 2011 Aug 30;58(10):1068-76.
• Isbell DC, Berr SS, Toledano AY, Epstein FH, Meyer CH, Rogers WJ, Harthun NL, Hagspiel KD, Weltman A, Kramer CM. Delayed calf muscle phosphocreatine recovery after exercise identifies peripheral arterial disease. J Am Coll Cardiol. 2006 Jun 6;47(11):2289-95. Epub 2006 May 15.
• Isbell DC, Meyer CH, Rogers WJ, Epstein FH, DiMaria JM, Harthun NL, Wang H, Kramer CM. Reproducibility and reliability of atherosclerotic plaque volume measurements in peripheral arterial disease with cardiovascular magnetic resonance. J Cardiovasc Magn Reson. 2007;9(1):71-6. Erratum in: J Cardiovasc Magn Reson. 2007;9(3):629.
• Isbell DC, Epstein FH, Zhong X, DiMaria JM, Berr SS, Meyer CH, Rogers WJ, Harthun NL, Hagspiel KD, Weltman A, Kramer CM. Calf muscle perfusion at peak exercise in peripheral arterial disease: measurement by first-pass contrast-enhanced magnetic resonance imaging. J Magn Reson Imaging. 2007 May;25(5):1013-20.
• Kramer CM. Peripheral arterial disease assessment: wall, perfusion, and spectroscopy. Top Magn Reson Imaging. 2007 Oct;18(5):357-69.
• Anderson JD, Epstein FH, Meyer CH, Hagspiel KD, Wang H, Berr SS, Harthun NL, Weltman A, Dimaria JM, West AM, Kramer CM. Multifactorial determinants of functional capacity in peripheral arterial disease: uncoupling of calf muscle perfusion and metabolism. J Am Coll Cardiol. 2009 Aug 11;54(7):628-35.

Inclusion Criteria:

Patients age 30-85 referred to the vascular imaging laboratory with documented evidence of peripheral arterial disease (0.4<ABI<0.9) 96 Normal healthy subjects ages 30-85

Exclusion Criteria:

Age<30, >85

GFR less than 45mL/min based on a serum creatinine drawn within 90 days of the MRI:

Pregnancy Contraindications to a magnetic resonance examination

• Intracranial clips
• Implantable pacemaker and defibrillator
• Cochlear or intraocular implants
• Claustrophobia
• Any metallic implant not listed as magnetic resonance compatible in Shellock F.G ---Pocket Guide to Magnetic Resonance Procedures and Metallic Objects, Update 2000. Lippincott, Williams and Wilkins