Epicardial fat as a cause of heart failure
“Overall obesity, as measured by a BMI greater than 30kg/m2, was previously seen as one of the main factors in the development of heart failure, but an increasing number of studies indicate that epicardial fat may be an even more important factor in heart failure”, says Van Woerden. The influence of epicardial fat on the prognosis of patients with heart failure was still unknown.
Poor prognosis independent of heart failure severity, BMI and comorbidities
Van Woerden and Gorter investigated whether epicardial fat also influenced the prognosis of patients with heart failure. In their study, they measured the volume of epicardial fat in 105 patients with heart failure by using MRI scans of the heart. The results showed that patients with a lot of epicardial fat were more often hospitalized for heart failure and more often died than patients with little epicardial fat. Importantly, this association was independent of BMI, heart failure severity, and comorbidities of the patient. In addition, it was found that even patients with obesity and a lot of epicardial fat were significantly more often hospitalized for heart failure and more often died than patients with obesity and little epicardial fat. These results support the concept that epicardial fat accumulation plays an important role in heart failure, regardless of the presence of obesity.
Measuring epicardial fat in the clinic
Van Woerden explains what the results of the study could mean for the clinic: “In the consulting room it is important to realize that a patient with a low BMI does not necessarily have little epicardial fat. In this study we saw that 22% of the patients with a BMI below 30kg/m2 had a lot of epicardial fat. That is why we should not only look at BMI to estimate whether someone has a lot or little epicardial fat, but also to specifically determine the amount of epicardial fat, by means of MRI or CT scans.” Gorter also mentions the use of other parameters that can say something about a patient's overall amount of fat, such as waist-to-hip ratio and waist circumference. These parameters give a much better impression of a patient's amount of fat than BMI alone and thus possibly also a better estimate of the patient's individual risk of heart failure.
A second study on this subject by fellow researcher Navin Suthahar (postdoc in the Department of Cardiology, UMCG), recently published in Nature Scientific Reports, shows that a patient's relative fat mass, measured by height and waist circumference, is much more strongly associated with the development of heart failure than, for example, BMI. This corresponds with the results of Van Woerden and Gorter, who argue in favor of measuring other parameters, in addition to BMI, for estimating the risk of heart failure.
In follow-up research, Van Woerden and Gorter want to investigate, among other things, whether epicardial fat can also be treated specifically, apart from overall obesity.
Read Van Woerden and Gorter's publication in Circulation: Heart Failure here
Read Suthahar's publication in Nature Scientific Reports here