Author + information
- Ivan Cokic,
- Avinash Kali,
- Hsin-Jung Yang,
- Richard Tang,
- Joseph Francis and
- Rohan Dharmakumar
Background: Fat deposition in chronic myocardial infarctions (MI) is a common finding. It is typically observed in the peri-infarct border zone (BZ) of old scars and has been linked to adverse outcomes in the chronic post-MI setting. To date, the mechanism underlying fat accumulation in infarcted myocardium remains unknown. Since iron is known to promote adipogenesis, we hypothesized that fatty infiltration in hemorrhagic MIs occurs in the regions with persistent iron deposits (PID).
Methods: Fourteen dogs were subjected to 3-hour occlusion of the LAD artery, followed by reperfusion. All dogs underwent T2* and LGE CMR 7 days after MI. Hearts were explanted 6 months post-MI. Paraffin and frozen histology sections were used to investigate the presence of fat and PID in CMI.
Results: Intramyocardial hemorrhage (IMH) was detected in 10 out of 14 dogs by T2* CMR. Only dogs positive for IMH in subacute MI showed evidence of fatty infiltration and PID in CMI. Moreover, fat depots in the peri-infarct BZ exclusively colocalized with Prussian Blue (PB)-stained iron (Examples: sub-endocardial region in Fig 1A, mid-myocardial region in Fig 1B). Foam cell formation in the iron-laden regions was confirmed by Oil Red O staining (Fig 2).
Conclusions: Here we demonstrate that persistent iron deposits from hemorrhagic MI are intimately linked with the process of fatty infiltration within peri-infarct BZ. Our data suggests that iron plays a critical role in adverse cardiac remodeling throughout the chronic phase of hemorrhagic MI.
Poster Hall, Hall C
Friday, March 17, 2017, 3:45 p.m.-4:30 p.m.
Session Title: Biomarkers and Targets for Ischemic Heart Disease
Abstract Category: 1. Acute and Stable Ischemic Heart Disease: Basic
Presentation Number: 1164-297
- 2017 American College of Cardiology Foundation