Changes in remote myocardial tissue after acute myocardial infarction and its relation to cardiac remodeling: A CMR T1 mapping study.

P Stefan Biesbroek,Peter M Van De Ven,Aernout M Beek,Raquel P Amier,Niels Van Royen,Paul F A Teunissen,Lourens F H J Robbers,Robin Nijveldt,Mark B M Hofman,Albert C Van Rossum

doi:10.1371/journal.pone.0180115

P Stefan Biesbroek, Peter M Van De Ven + Show 8 more

Open Access

https://doi.org/10.1371/journal.pone.0180115

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Journal: PloS one	Publication Date: Jun 23, 2017
Citations: 36	License type: CC BY 4.0

Affiliation: Amsterdam UMC Location VUmc, Netherlands Heart Institute

Abstract

ObjectivesTo characterize the temporal alterations in native T1 and extracellular volume (ECV) of remote myocardium after acute myocardial infarction (AMI), and to explore their relation to left ventricular (LV) remodeling.MethodsForty-two patients with AMI successfully treated with primary PCI underwent cardiovascular magnetic resonance after 4–6 days and 3 months. Cine imaging, late gadolinium enhancement, and T1-mapping (MOLLI) was performed at 1.5T. T1 values were measured in the myocardial tissue opposite of the infarct area. Myocardial ECV was calculated from native- and post-contrast T1 values in 35 patients, using a correction for synthetic hematocrit.ResultsNative T1 of remote myocardium significantly decreased between baseline and follow-up (1002 ± 39 to 985 ± 30ms, p<0.01). High remote native T1 at baseline was independently associated with a high C-reactive protein level (standardized Beta 0.32, p = 0.04) and the presence of microvascular injury (standardized Beta 0.34, p = 0.03). ECV of remote myocardium significantly decreased over time in patients with no LV dilatation (29 ± 3.8 to 27 ± 2.3%, p<0.01). In patients with LV dilatation, remote ECV remained similar over time, and was significantly higher at follow-up compared to patients without LV dilatation (30 ± 2.0 versus 27 ± 2.3%, p = 0.03).ConclusionsIn reperfused first-time AMI patients, native T1 of remote myocardium decreased from baseline to follow-up. ECV of remote myocardium decreased over time in patients with no LV dilatation, but remained elevated at follow-up in those who developed LV dilatation. Findings from this study may add to an increased understanding of the pathophysiological mechanisms of cardiac remodeling after AMI.

Highlights

Following acute myocardial infarction (AMI), the infarcted myocardium undergoes a sequence of pathophysiological changes including myocardial necrosis, myocardial edema, microvascular injury, and subsequent healing with scar tissue formation [1]
extracellular volume (ECV) of remote myocardium significantly decreased over time in patients with no left ventricular (LV) dilatation (29 ± 3.8 to 27 ± 2.3%, p
In patients with LV dilatation, remote ECV remained similar over time, and was significantly higher at follow-up compared to patients without LV dilatation (30 ± 2.0 versus 27 ± 2.3%, p = 0.03)

Summary

Introduction

Following acute myocardial infarction (AMI), the infarcted myocardium undergoes a sequence of pathophysiological changes including myocardial necrosis, myocardial edema, microvascular injury, and subsequent healing with scar tissue formation [1]. Pathological changes in myocardial tissue composition can be evaluated using cardiovascular magnetic resonance (CMR) imaging. Native (i.e. pre-contrast) T1 mapping permits direct quantification of the absolute T1 relaxation times, and can be used to detect and quantify myocardial edema, without the need for a reference region [4,5,6]. Post-contrast T1 mapping enables quantification of gadolinium (Gd)-based contrast accumulation within the interstitial space of the myocardium, and thereby provides a direct measure of the size of the extracellular volume (ECV) [7]

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