Quantification of Intramyocardial Lipid by Proton Magnetic Resonance Spectroscopy

Study Overview
=================
Brief Summary
-----------------
Accumulation of triglycerides in heart tissue has been associated with changes in left ventricular function which can lead to heart failure. Proton magnetic resonance spectroscopy is currently the only non-invasive in vivo method to measure myocardial triglycerides content. The primary goal of this study was to determine if Magnetic Resonance Spectroscopy could effectively measure myocardial triglyceride content in myocardial heart tissue. Thus, quantitative and reliable techniques to monitor in vivo triglyceride accumulation in the heart are important for disease diagnosis and management. Currently, no such imaging method exists.

Detailed Description
-----------------
Because routine biopsy of the myocardium is not feasible, MRS is the most promising technique for the quantification of myocardial triglycerides. MRS is routinely used to precisely characterize metabolite concentrations in muscle and liver. 14-16 Studies such as monitoring the levels of deoxymyoglobin and real-time tracking of the postprandial accumulation of cellular lipids are examples of its diversity and potential.15,17,18 Generally, these studies suggest that the reproducibility of MRS is between 2 and 6%.18,19 In vivo cardiac MRS provides unique challenges because of the requirement to compensate for concurrent heart and lung motion. Using cardiac and respiratory gating to minimize motional artifacts, an initial validation study found a variation of 17% for sequential measurements, attributing the major error to residual motional effects. 20 Moreover, measurements were limited to the inter-ventricular septum. Using navigator and cardiac gating appeared to give a slight, 4%, improvement, but this was a preliminary study and no validation was done.21 For a comprehensive clinical validation, other reproducibility factors must be addressed. Variations due to post-processing, coil placement and calibration, trigger reproducibility, internal versus external standard, shimming, and protocol sequence variables such as pulse quality, gradient strength, voxel size, relaxation time, echo time, and the number of scan repetitions are all known sources of reproducibility. 17,19,22-24 All of these variables must be characterized in order to achieve optimal inter- scanner and subject reproducibility along with accurate treatment tracking capability. Therefore, 10 normal healthy volunteers were imaged to determine the reliability of the MRS protocol with test-re-test measurements. The 8 heart transplant patients were imaged prior to their routine heart biopsies, and then the myocardial biopsy tissue was measure and compared to the pre-biopsy images.

Official Title
-----------------
Quantification of Intramyocardial Lipid by Proton Magnetic Resonance Spectroscopy

Conditions
-----------------
Heart Transplantation

Intervention / Treatment
-----------------
* Procedure: Magnetic Resonance Spectroscopy
* Procedure: Ex vivo heart biopsy


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: healthy volunteers heart transplant patients undergoing post transplant endomyocardial biopsy not experiencing significant rejection heart transplant patients must be 18-30 years old. Exclusion Criteria: <18 or >45 pregnant significant systemic illness actively ill acute transplant rejection any condition that would prevent a participant from completing the NMR spectroscopy (i.e pacemakers, claustrophobia)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Compare magnetic resonance imaging measurements of triglyceride accumulation in myocardial tissue with ex vivo myocardial tissue collected from heart transplant patients who have had routine clinical heart biopsy.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Magnetic Resonance Spectroscopy<br>Patients will have Magnetic Resonance Spectroscopy to measure in vivo accumulation of triglycerides in myocardial tissue | Procedure: Magnetic Resonance Spectroscopy<br>* Magnetic Resonance Spectroscopy is a noninvasive procedure that provides detailed body images on any plane.<br>* Other names: MRS;|
| Experimental: Ex vivo heart biopsy<br>Patients will have their normal routine clinical heart biopsy of myocardial heart tissue. | Procedure: Ex vivo heart biopsy<br>* Heart transplant patients will have their normal clinical routine heart biopsy<br>* Other names: heart biopsy;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation Co-efficient Between MRS Spectroscopy and Endomyocardial Biopsy in Heart Transplant Participants | Participants first had MRS spectroscopy then the MRS spectroscopy images were compared to endomyocardial biopsy | 2 to 10 days | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Heart, Transplant, MRS, MRI, Spectroscopy