Non-Biased Fat Scoring System For Human Cardiac Variability And Body Mass Index Correlation Analyses

Introduction: It remains unclear if body mass index (BMI) is correlated to the amount of cardiac adipose tissue in humans. Echocardiography is typically utilized to measure epicardial fat in live patients, but has yielded inconclusive results, as it is difficult to measure cardiac adipose tissue levels from a single location on a 1-dimensional image, as fat is not always distributed equally across the heart. Methods: Through the Ohio State Cardiac Research Tissue program, we have collected over 200 human hearts of various conditions. Multi-angle photographs are available for every heart. We developed an adipose tissue scoring system, so correlations can be drawn between the adipose tissue score (ATS), and BMI in failing and non-failing human hearts. Hearts were scored based on the multi-angle photographs. Each heart was given an atrial (AATS) and a ventricular score (VATS) ranging from 0-7, based on fat distribution and epicardial fat thickness. Nine sets of scores by individuals blinded to any patient information were averaged for each heart and the average ATS was plotted for correlation analyses against BMI and etiology. Results: A strong correlation was not apparent by plotting BMI versus VATS for all failing and non-failing hearts (R 2 = 0.011915 failing, 0.017262 non-failing). It is of interest to note that the lower right quadrant of the correlation plot is empty, indication that in patients with high BMI, the ATS was also high. However, in individuals with low BMI, there was a wide distribution of ATS. VATS and AATS are closely correlated in both failing (R 2 = 0.67082) and non-failing (R 2 = 0.84446) hearts. Conclusions: Our analysis shows that in humans, a high BMI is typically correlated with a high ATS score, but a low BMI does not necessarily correlate with a low ATS. The non-failing hearts have a stronger correlation between VATS and AATS compared to the failing hearts, suggesting that failing hearts do not always have an equal distribution of adipose tissue between the atria and ventricle. Future studies will investigate the presence of correlation between ATS with other parameters, such as age, gender, and race.