Role of genetics to be explored
“This study highlights the need for further investigation into these individuals because, at the moment, we can’t be sure that the only contributing factor to this is the obesity,” said Dr. Westaby.
In the works are plans to see if there may be an underlying genetic predisposition in obese individuals that may have contributed to the development of an enlarged heart. The group also plans to study the families of the deceased individuals to determine if they are at risk of developing cardiomegaly, he said.
“This paper makes an important contribution to the literature that raises many important questions for future research,” Timothy P. Fitzgibbons, MD, PhD, from the University of Massachusetts, Worcester, wrote in an accompanying editorial.
Being able to access so many autopsy samples gives the current study considerable heft, Dr. Fitzgibbons said in an interview.
“A lot has been made of the obesity paradox and the perhaps benign nature of obesity but this paper suggests the opposite, that it is a very serious problem and can, in fact, in and of itself, cause heart abnormalities that could cause sudden death,” he noted.
The fact that only 13% of OCM cases had fibrosis on histology suggests that fibrosis was not the main cause of sudden cardiac death, he said.
“Often we will do MRIs to look for areas of fibrosis within the heart because those areas make patients prone to re-entry arrhythmias, in particular, ventricular tachycardia. But the authors suggest that the enlarged myocytes may themselves be predisposing to arrhythmias, rather than fibrosis,” Dr. Fitzgibbons said.
The study was supported by Cardiac Risk in the Young. Dr. Westaby and Dr. Fitzgibbons have reported no relevant financial relationships.
A version of this article appeared on Medscape.com.