CHARLOTTESVILLE, Va. -- Your heart harbors a secret: a layer of fat that can either protect it or potentially contribute to its demise. Now, University of Virginia researchers have invented a revolutionary MRI technique that allows them to study this enigmatic tissue in unprecedented detail, potentially opening new frontiers in cardiac medicine.
This innovative technique examines epicardial adipose tissue (EAT), a specialized fat layer that wraps around our hearts. While EAT naturally serves protective functions in healthy individuals, providing both energy reserves and thermal insulation for the heart, it can undergo concerning changes under certain conditions.
The research team, led by Dr. Frederick H. Epstein, of UVA's Department of Biomedical Engineering, developed this specialized MRI technique to examine the fatty acid composition of EAT, measuring different types of fats: saturated, monounsaturated, and polyunsaturated fatty acids.
"Using this new MRI technique, we now for the very first time have the ability to know the composition of the fat that accumulates around the heart. This is important because depending on its makeup, the fat which surrounds the heart has the potential to release damaging substances directly into the heart muscle, leading to serious heart problems," explains researcher Amit R. Patel, MD, a cardiologist and imaging expert at UVA Health.
To test their new imaging method, the researchers studied 21 patients who had experienced ST-segment elevation myocardial infarction (STEMI), a severe type of heart attack. All patients were examined within 96 hours after blood flow was restored to their hearts. The study group included 14 men and seven women, with an average age of 62.6 years.
The technique provides detailed insights into EAT composition that weren't previously possible with conventional imaging. Understanding the proportions of different fat types is crucial because each affects heart health differently. For instance, saturated fats have been linked to inflammatory responses in adipose tissue, while certain unsaturated fats may help counter inflammation.
One of the major technical achievements was developing a method that could capture clear images despite the constant motion of the heart and lungs. "The ability to make these measurements in epicardial adipose tissue required the use of advanced computational methods that can extract the unique signature of saturated fatty acids from an overall noisy signal," explains Epstein, who also serves as associate vice president for research at UVA.
The study found distinct differences in EAT composition compared to other fat deposits in the body. Notably, the researchers discovered significant correlations between EAT composition and measures of heart function and structure in STEMI patients. The findings suggest that analyzing EAT composition might provide valuable insights into cardiac health and disease progression.
Looking ahead, Dr. Patel envisions potential therapeutic applications. "With our ongoing research, we hope to show that we can convert the unhealthy fat which surrounds the heart to a more healthy type of fat with either diet and exercise or through the use of medications. We believe that by doing so, we will be able to reduce some of the complications associated with heart disease."
From protective cushion to potential indicator of heart health, the fat surrounding our hearts may hold crucial clues about cardiac disease. This new imaging technique brings us closer to understanding its complex role.