Absolute Quantification of Coronary Flow Reserve by Stress Perfusion MRI
Coronary artery disease (CAD, coronary heart disease) is the leading cause of death in the U.S., causing 1 in 5 deaths in 2005. The current method for diagnosing coronary artery disease that is considered most accurate is coronary angiography however it involves risk and radiation. Alternatively nuclear imaging test and MRI stress test only permits the semi qualitative analysis of the myocardial perfusion images.
In this proposal the investigators will develop a means to calculate Coronary Flow Reserve (CFR) using the MRI. the investigators approach has the potential to reduce mortality from myocardial infarction by effecting a change in the patient management paradigm. Absolute quantification of myocardial perfusion will detect coronary stenosis and CAD in patients with more accuracy than the semi-quantitative or qualitative analysis of perfusion images. Measurement of Coronary Flow Reserve is important for the following reasons: decrease of coronary flow reserve has been identified as a first effect of CAD; it provides an objective measure of treatment efficacy.
The purpose of this study is to compare images from nuclear stress test and/or coronary angiography with Magnetic Resonance Imaging (MRI) that will evaluate subjects with coronary artery disease calculating myocardial blood flow using a novel MRI technique combined to an extracellular Gadolinium-based contrast agent and stressor agent
Drug: gadofoveset trisodium
|Study Design:||Intervention Model: Single Group Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Diagnostic
|Official Title:||Absolute Quantification of Coronary Flow Reserve by Stress Perfusion MRI|
- Quantification of Myocardial Blood Volume [ Time Frame: outcome measured following single MRI scan ]The investigators anticipated that a novel MRI imaging protocol using a high relaxivity blood-pool contrast agent (gadofosveset trisodium) would be capable of quantifying coronary flow reserve based on quantification of myocardial blood volume and would be correlated with myocardial flow reserve as measured in low spatial resolution nuclear SPECT scans. Pre- and post- gadofosveset trisodium images were to be used to calculate the myocardial blood volume. Myocardial blood volume is derived from an equation of the relaxation times of hydrogen atoms in the blood and myocardium. If the agent administered did not behave as a true intravascular agent in the myocardium, quantification of myocardial intravascular blood volume (and hence a calculated coronary flow reserve) could not be calculated using the specified approach. In this case, relaxation times would be reported. Relaxation (R) times are measured in inverse seconds.
- Coronary Blood Volume Calculation Using MRI Stress Perfusion [ Time Frame: 18 months ]The investigators anticipate that CBV changes (in ml/100g of tissue) under stress reflect complementary physiologic feed back to stress perfusion scans, contrary to the hypothesis by many groups who claim that cardiac BOLD and/or rest-perfusion scans can determine without recourse to exercise or pharmacological stress.
|Study Start Date:||September 2012|
|Study Completion Date:||February 2014|
|Primary Completion Date:||February 2014 (Final data collection date for primary outcome measure)|
Experimental: coronary artery disease patients
Patients with suspected coronary artery disease prospectively recruited for myocardial perfusion MRI. All subjects to receive 5 ml IV gadofoveset trisodium contrast (Ablavar, Lantheus) at both stress and rest. Stress to be induced using 5 ml intravenous (IV) regadenoson (Lexiscan, Astellas US LLC), and the effects of regadenoson were reversed with 50 mg IV aminophylline following the completion of stress imaging.
Regadenoson will be infused intravenously 0.4 mg/5 mL (0.08 mg/mL) as a single bolus.
Other Name: LexiscanDrug: gadofoveset trisodium
All subjects to receive 5 ml IV gadofoveset trisodium contrast (Ablavar) at both stress and rest.
Other Name: Ablavar
The main hypothesis the investigators will test is that changes in myocardial blood volume, under physiologic stress, correlate with myocardial flow reserve as measured in low spatial resolution nuclear SPECT scans. Secondary hypothesis is that stress perfusion as quantified with bolus height corrected gadofosveset trisodium images, better correlate with SPECT perfusion than uncorrected, relative perfusion values.
The investigators propose implementing the scan protocol using a 1.5T or 3.0T MRI scanner. The investigators will scan a series of 20 patients recruited from the nuclear stress lab at Northwestern Memorial Hospital. These subjects will be approached and enrolled into a HIPPA Compliant, IRB approved research study to assess the effectiveness of myocardial perfusion and blood volume images to measure myocardial blood volume. Subjects will be scanned with a modified version of the clinical stress-perfusion protocol. Correlation analysis will be used to test the hypothesis that quantitative blood volume is an indicator of myocardial flow reserve.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01655043
|United States, Illinois|
|Chicago, Illinois, United States, 60611|
|Principal Investigator:||James C Carr, MD||Northwestern University|