Cardiovascular Magnetic Resonance Imaging in Cardiometabolic Disease
Abstract
The unrelenting incidence of obesity and type 2 diabetes has become a global public health concern. Cardiovascular disease (CVD) remains the leading cause of morbidity and mortality in these cohorts. Cardiovascular Magnetic Resonance (CMR) imaging is a robust imaging modality with techniques to provide sensitive detection of early cardiovascular changes in obesity and diabetes.
In a prospective study of obese adolescents (n=11, 10 to 20 years old) and a healthy weight control group (n=14), we found obesity was associated with increases in Left ventricular (LV) mass, LV wall thickness and mass:volume ratio. In this “early stage” of remodeling, these structural changes were not associated with elevations in Native T1, a surrogate marker of tissue fibrosis. Strain analysis, by novel CMR tissue tracking analysis, revealed a hyper-contractile state, likely representing a combined contribution of elevated systolic blood pressure with compensatory myocyte hypertrophy. Obese subjects were additionally enrolled in a comprehensive 6-month lifestyle intervention; subjects did not experience weight loss or any change in cardiac parameters after 6 months.
Further along the natural history of CVD as related to metabolic disease, the second study looked to examine possible sub-clinical changes in the hearts of otherwise healthy diabetic patients. This study examined twenty-eight healthy type 2 diabetic patients without any observable vascular complications. The complementary use of CMR-based T1 mapping and 3-dimensional strain analysis demonstrated expansion of the extracellular matrix and a reduction in global longitudinal strain.
In the endpoint of the cardiometabolic disease spectrum, we analyzed individuals with known or suspected Coronary Artery Disease. This study explored the relationship between intra-thoracic fat volume (ITFV) and 4D myocardial strain-based markers of adverse remodeling. In non-infarcted myocardium, ITFV is associated with reductions in myocardial strain. These findings suggest ITFV to be a potentially important marker of adverse ventricular remodeling.
The findings of these three studies suggest a capacity of contemporary CMR to identify early changes in cardiometabolic disease and also lend insight into the progression of diabetic heart disease. CMR provides a non-invasive, accurate and reproducible imaging modality with the potential to be useful in screening and CVD risk-stratification.
Description
Keywords
Biophysics--Medical
Citation
Schmidt, A. (2016). Cardiovascular Magnetic Resonance Imaging in Cardiometabolic Disease (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25216