Influence of Myocardial Hemorrhage on Staging of Reperfused Myocardial Infarctions With T2 Cardiac Magnetic Resonance Imaging: Insights Into the Dependence on Infarction Type With Ex Vivo Validation

Guan Wang; Hsin-Jung Yang; Avinash Kali; Ivan Cokic; Richard Tang; Guoxi Xie; Qi Yang; Joseph Francis; Songbai Li; Rohan Dharmakumar

doi:10.1016/j.jcmg.2018.01.018

JACC: Cardiovascular Imaging

Volume 12, Issue 4, April 2019 DOI: 10.1016/j.jcmg.2018.01.018

Influence of Myocardial Hemorrhage on Staging of Reperfused Myocardial Infarctions With T₂ Cardiac Magnetic Resonance Imaging
Insights Into the Dependence on Infarction Type With Ex Vivo Validation

Guan Wang, Hsin-Jung Yang, Avinash Kali, Ivan Cokic, Richard Tang, Guoxi Xie, Qi Yang, Joseph Francis, Songbai Li and Rohan Dharmakumar

Author + information

vol. 12 no. 4 693-703

DOI:

https://doi.org/10.1016/j.jcmg.2018.01.018

Published By:

JACC: Cardiovascular Imaging

Print ISSN:

1936-878X

Online ISSN:

1876-7591

History:

Received August 23, 2017
Revision received January 17, 2018
Accepted January 18, 2018
Published online April 1, 2019.

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2019 The Authors

Author Information

Guan Wang, MD^a,^b,
Hsin-Jung Yang, PhD^b,
Avinash Kali, PhD^b,
Ivan Cokic, MD^b,
Richard Tang, MD^b,
Guoxi Xie, PhD^c,
Qi Yang, MD^b,
Joseph Francis, PhD^d,
Songbai Li, MD^a,^∗∗ (songbaili001{at}163.com) and
Rohan Dharmakumar, PhD^b,^c,^e,^∗ (rohandkumar{at}csmc.edu)

^aDepartment of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, China
^bBiomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
^cDepartment of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
^dDepartment of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
^eDavid Geffen School of Medicine, University of California, Los Angeles, California

↵∗Address for correspondence:
Dr. Rohan Dharmakumar, Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, PACT Building–Suite 400, 8700 Beverly Boulevard, Los Angeles, California 90048.
↵∗∗Dr. Songbai Li, Department of Radiology, The First Affiliated Hospital of China Medical University, No.155 North Nanjing Street, Shenyang, Liaoning, China 110001.

Graphical abstract

Abstract

Objectives This study sought to determine whether T₂ cardiac magnetic resonance (CMR) can stage both hemorrhagic and nonhemorrhagic myocardial infarctions (MIs).

Background CMR-based staging of MI with or without contrast agents relies on the resolution of T₂ elevations in the chronic phase, but whether this approach can be used to stage both hemorrhagic and nonhemorrhagic MIs is unclear.

Methods Hemorrhagic (n = 15) and nonhemorrhagic (n = 9) MIs were created in dogs. Multiparametric noncontrast mapping (T₁, T₂, and T₂*) and late gadolinium enhancement (LGE) were performed at 1.5- and 3.0-T at 5 days (acute) and 8 weeks (chronic) post-MI. CMR relaxation values and LGE intensities of hemorrhagic, peri-hemorrhagic, nonhemorrhagic, and remote territories were measured. Histopathology was performed to elucidate CMR findings.

Results T₂ of nonhemorrhagic MIs was significantly elevated in the acute phase relative to remote territories (1.5-T: 39.8 ± 12.8%; 3.0-T: 27.9 ± 16.5%; p < 0.0001 for both) but resolved to remote values by week 8 (1.5-T: −0.0 ± 3.2%; p = 0.678; 3.0-T: −0.5 ± 5.9%; p = 0.601). In hemorrhagic MI, T₂ of hemorrhage core was significantly elevated in the acute phase (1.5-T: 17.7 ± 10.0%; 3.0-T: 8.6 ± 8.2%; p < 0.0001 for both) but decreased below remote values by week 8 (1.5-T: −8.2 ± 3.9%; 3.0-T: −5.6 ± 6.0%; p < 0.0001 for both). In contrast, T₂ of the periphery of hemorrhage within the MI zone was significantly elevated in the acute phase relative to remote territories (1.5-T: 35.0 ± 16.1%; 3.0-T: 24.2 ± 10.4%; p < 0.0001 for both) and remained elevated at 8 weeks post-MI (1.5-T: 8.6 ± 5.1%; 3.0-T: 6.0 ± 3.3%; p < 0.0001 for both). The observed elevation of T₂ in the peri-hemorrhagic zone of MIs and the absence of T₂ elevation in nonhemorrhagic MIs were consistent with ongoing or absence of histological evidence of inflammation, respectively.

Conclusions Hemorrhagic MIs are associated with persisting myocardial inflammation and edema, which can confound staging of hemorrhagic MIs when T₂ elevations alone are used to discriminate between acute and chronic MI. Moreover, given the poor prognosis in patients with hemorrhagic MI, CMR evidence for myocardial hemorrhage with persistent edema may evolve as a risk marker in patients after acute MI.

Key Words

Footnotes

This work was supported in part by grants HL136578 and HL133407 from the National Heart, Lung, and Blood Institute to Dr. Dharmakumar. All authors have reported that they have no relationships relevant to the contents of this paper to disclose.