Comprehensive Evaluation of Ischemic Heart Disease Using MRI

Coronary heart disease is the leading cause of death and disability in the US, accounting for about one-third of all deaths in subjects over age 35.

With the development of newer Magnetic Resonance Imaging (MRI) techniques, such as faster pulse sequences and parallel imaging, cardiac MRI has become a routine tool for the evaluation and detection of myocardial ischemic disease. First pass myocardial perfusion (FPMP) using MRI is increasingly being used to assess ischemic heart disease. MRI offers the advantages of spatial resolution sufficient to differentiate between subendocardial and subepicardial perfusion; shorter examination time and also lack of ionizing radiation. Left ventricle cine gradient echo imaging can be used to assess regional ventricular function. Left ventricular myocardial viability can also be easily assessed at the same time in order to determine the amount of viable left ventricular myocardium and the percentage of irreversibly scarred myocardium by delayed enhanced images. Viability imaging is usually added to the perfusion protocol to increase specificity by allowing detection of fixed perfusion defects, which represent scar. The ultimate cardiac MRI protocol would be to combine both of these imaging strategies with a reliable and accurate coronary Magnetic Resonance Angiography(MRA) technique, such that obstructive coronary artery disease could be evaluated comprehensively at the same time. If all of these techniques can be combined together in a single study, it may be feasible to finally achieve a "one stop shop" for cardiac Magnetic Resonance Imaging.

Inclusion criteria

Under an Institutional Committee on Human Research board approved protocol 80 patients with a suspected myocardial ischemic disease recruited from the cardiac cath laboratory will be recruited in this prospective study. Volunteers will be recruited for the purpose of protocol development and will not be included in analysis. All subjects will be screened for glomerular filtration rate (GFR) within 24 hours before the exam. All patients must have a GFR > 30 mL/min/1.73m2 to be part of the study.

All subjects will be selected following the Nephrogenic Systemic Fibrosis (NSF) guidelines. All dialysis patients or end-stage renal disease patients with a creatinine clearance of < 30 mL/min will not be selected for the study to avoid NSF. Patients with GFR < 60 ml/min but >30 ml/min will receive a reduced dose of Gadolinium contrast (0.1 ml/kg).

Exclusion criteria

• Age <18 years;
• Known contraindication to MR imaging (such as pacemaker placement, magnetic implants, etc);
• Claustrophobia;
• Inability to perform an adequate breath-hold for imaging,
• Inability to provide informed consent;
• all subjects will be will be screened for GFR within 24 hours before the exam and subjects presenting with GFR < 30 ml/min will be excluded;
• Pregnant and lactating women;
• Patients with hypersensitivity to gadolinium contrast agents, metoprolol, adenosine, or nitroglycerin;
• Contra indication for Adenosine

• 2nd- or 3rd-degree atrioventricular block (except in patients with a functioning artificial pacemaker)
• Sinus node disease (except in patients with a functioning artificial

pacemaker)

• Unstable angina
• Acute myocardial infarction
• Known or suspected bronchoconstrictive or bronchospastic lung

disease (e.g., asthma)

• Hypersensitivity to adenosine
• Caffeine within 12-24 hours
• Theophylline and Dipyridamole products within 24 hours.
• Contra indication for Metoprolol

• sinus bradycardia
• heart block greater than first degree
• Cardiac Failure
• Bronchospastic Disease
• Contra indication for Nitroglycerin

• Early myocardial infarction, severe anemia, increased intracranial pressure, and those with a known hypersensitivity to nitroglycerin.

b .Administration of Nitrostat (nitroglycerin tablets, USP) is contraindicated in patients who are using Viagra® since Viagra has been shown to potentiate the hypotensive effects of organic nitrates.