Ventricular Myocardial Fat: An Unexpected Biomarker for Long-term Survival?
To examine the association between myocardial fat, a poorly understood finding frequently observed on non-contrast CT, and all-cause mortality in patients with and without a history of prior MI.
Materials and methods
A retrospective cohort from a diverse urban academic center was derived from chronic myocardial infarction (MI) patients (n = 265) and three age-matched patients without MI (n = 690) who underwent non-contrast chest CT between 1 January 2005-31 December 2008. CT images were reviewed for left and right ventricular fat. Electronic records identified clinical variables. Kaplan-Meier and Cox proportional hazard analyses assessed the association between myocardial fat and all-cause mortality. The net reclassification improvement assessed the utility of adding myocardial fat to traditional risk prediction models.
Mortality was 40.1% for the no MI and 71.7% for the MI groups (median follow-up, 6.8 years; mean age, 73.7 ± 10.6 years). In the no MI group, 25.7% had LV and 49.9% RV fat. In the MI group, 32.8% had LV and 42.3% RV fat. LV and RV fat was highly associated (OR 5.3, p < 0.001). Ventricular fat was not associated with cardiovascular risk factors. Myocardial fat was associated with a reduction in the adjusted hazard of death for both the no MI (25%, p = 0.04) and the MI group (31%, p = 0.018). Myocardial fat resulted in the correct reclassification of 22% for the no MI group versus the Charlson score or calcium score (p = 0.004) and 47% for the MI group versus the Charlson score (p = 0.0006).
Patients with myocardial fat have better survival, regardless of MI status, suggesting that myocardial fat is a beneficial biomarker and may improve risk stratification.
• Myocardial fat is commonly found on chest CT, yet is poorly understood
• Myocardial fat is associated with better survival in patients with and without prior MI and is not associated with traditional cardiovascular risk factors
• This finding may provide clinically meaningful prognostic value in the risk stratification of patients
KeywordsBiomarkers Myocardium Risk assessment Tomography, x-ray computed Outcomes research
Coronary artery disease
Net reclassification improvement
The preliminary findings were presented as an oral presentation at the Radiological Society of North America Annual Meeting, November 29, 2016, Chicago, IL.
This study has received funding by National Institutes of Health Clinical and Translational Science Awards Grant Number 1UL-1TR001073 from the National Center for Advancing Translational Sciences.
Compliance with ethical standards
The scientific guarantor of this publication is Dr. Anna S. Bader.
Conflict of interest
The authors of this manuscript declare relationships with the following companies: The spouse of L.B.H. is a board member of Kryon.
Statistics and biometry
One of the authors has significant statistical expertise.
The requirement for written informed consent was waived by the Institutional Review Board.
Institutional Review Board approval was obtained.
• performed at one institution
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