Connelly, Kim

Dick, Alexander J

Ghugre, Nilesh R

Graham, John J

Radau, Perry

Wright, Graham A

Zia, Mohammad I

Journal of Cardiovascular Magnetic Resonance

English

PubMed

Nilesh R Ghugre

Mohammad I Zia

Perry Radau

John J Graham

Kim Connelly

Alexander J Dick

Graham A Wright

Crossref

Evolution of gray zone after acute myocardial infarction: Influence of microvascular obstruction

Springer - Publisher Connector

POSTER PRESENTATION Open Access
Evolution of gray zone after acute myocardial
infarction: Influence of microvascular obstruction
Nilesh R Ghugre1*, Mohammad I Zia1, Perry Radau1, John J Graham2, Kim Connelly2, Alexander J Dick3,
Graham A Wright1
From 2011 SCMR/Euro CMR Joint Scientific Sessions
Nice, France. 3-6 February 2011
Introduction
The presence of ischemia-induced microvascular
obstruction (MVO) despite successful coronary revascu-
larization, has been associated with poor functional
recovery and adverse left ventricular remodeling after
acute myocardial infarction (AMI). Additionally, the
extent of the infarct gray zone is a strong independent
predictor of post-AMI mortality. However, the evolution
of gray zone after AMI has not been investigated and its
relationship with MVO in terms of risk stratification is
unknown.
Purpose
To characterize the evolution of gray zone and deter-
mine its correlation with the presence of MVO during
infarct healing in patients treated with primary percuta-
neous coronary intervention (PCI).
Methods
Patients were enrolled post-PCI and underwent MRI
examination on a 1.5T scanner (GE Signa Excite) at day
2, week 4 and month 6 following AMI. Cardiac function
[Ejection fraction (EF), End-diastolic volume (EDV)] was
evaluated using a steady-state-free-precession (SSFP)
sequence in cine mode. A T1-weighted IR-GRE
sequence was used for delayed-hyperenhancement
(DHE) of infarcted myocardium. Infarct core (IC) and
gray zone (GZ) volumes were quantified using the full-
width-half-maximum technique as previously described;
both quantities were expressed as a percentage of myo-
cardial volume. MVO’s were manually traced and
included in the infarct core calculation.
Results
Ten patients who completed MRI exams at all
three time points were included in the study [mean age:
59.7±11 years; 9 males, 1 female; 4 right coronary artery
and 2 left circumflex artery PCI; MVO was identified in
4 patients]. Figure 1 shows DHE images from represen-
tative patients in the MVO and non-MVO groups while
Tables 1, 2, 3 summarize the corresponding quantities
measured. Note that the following findings were signifi-
cant: (a) infarct core was reduced in all patients by
month 6; (b) MVO was resolved by week 4; (b) gray
zone size relative to infarct size, GZr = 100*GZ/(GZ+IC)
increased in the MVO group at month 6 while it
remained stable in the non-MVO group; (d) EF was
reduced in the MVO group compared to the non-MVO
at all time points (p<0.05). The percent change in GZr
(ΔGZr) at week 4 and month 6, relative to day 2 is
shown in Figure 2.
1Sunnybrook Health Sciences Centre, Toronto, ON, Canada
Full list of author information is available at the end of the article
Figure 1 Delayed-enhanced short-axis slices from two
representative patients in the MVO and non-MVO groups imaged at
three different time points post AMI. Color coding identifies three
regions: Infarct core (green), gray zone (yellow) and microvascular
obstruction (red).
Ghugre et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):P151
http://jcmr-online.com/content/13/S1/P151
© 2011 Ghugre et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons
Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in
any medium, provided the original work is properly cited.
Conclusions
The increase in infarct gray zone or arrhythmogenic
substrate may be one of the possible mechanisms
responsible for adverse remodeling and poor clinical
prognosis in patients with MVO. Monitoring the early
evolution of gray zone in the high-risk patients could
also potentially help identify the optimal timing and
candidates for placement of implantable cardioverter-
defibrillator.
Author details
1Sunnybrook Health Sciences Centre, Toronto, ON, Canada. 2St. Michael’s
Hospital, Toronto, ON, Canada. 3University of Ottawa Heart Institute, Ottawa,
ON, Canada.
Published: 2 February 2011
doi:10.1186/1532-429X-13-S1-P151
Cite this article as: Ghugre et al.: Evolution of gray zone after acute
myocardial infarction: Influence of microvascular obstruction. Journal of
Cardiovascular Magnetic Resonance 2011 13(Suppl 1):P151.
Submit your next manuscript to BioMed Central
and take full advantage of: 
• Convenient online submission
• Thorough peer review
• No space constraints or color figure charges
• Immediate publication on acceptance
• Inclusion in PubMed, CAS, Scopus and Google Scholar
• Research which is freely available for redistribution
Submit your manuscript at 
www.biomedcentral.com/submit
Table 1 All patients (N=10)
Day 2 Week 4 Month 6
GZ (%) 7.8±3.5 7.4±6.0 7.2±5.0
IC (%) 18.5±11.6 12.2±8.1 * 11.5±8.1 *
MVO (%) 3.5±5.1 0.2±0.3 0.2±0.4
EF (%) 47.4±7.1 49.8±7.8 51.5±11.1
EDV (ml) 123.2±30.3 143.9±33.0 117.0±23.8
GZr (%) 31.4±7.8 37.4±17.0 38.1±11.7
Values have been expressed as mean±standard deviation.
p-values were measured with respect to day 2 measurements by paired
Students t-test.
* p<0.01.
Table 2 non-MVO patients (N=6)
Day 2 Week 4 Month 6
GZ (%) 6.6±3.1 4.4±2.3 ** 4.5±2.7
IC (%) 11.8±4.5 8.9±6.6 7.5±5.3 **
MVO (%) 0 0 0
EF (%) 50.8±7.3 53.3±8.3 57.5±7.1
EDV (ml) 134.6±27.4 135.0±22.9 117.6±23.7
GZr (%) 34.5±5.7 30.3±11.8 33.6±10.2
Values have been expressed as mean±standard deviation.
p-values were measured with respect to day 2 measurements by paired
Students t-test.
** p<0.05.
Table 3 MVO patients (N=4)
Day 2 Week 4 Month 6
GZ (%) 9.7±3.6 12.0±7.2 11.3±5.0
IC (%) 28.5±12.0 17.2±8.2 ** 17.5±8.5 **
MVO (%) 8.7±4.2 0.4±0.5 ** 0.4±0.6 **
EF (%) 42.2±3.0 44.6±3.0 42.3±10.0
EDV (ml) 106.1±29.1 157.3±44.7 * 116.2±27.6 *
GZr (%) 26.1±8.7 39.4±18.5 38.9±10.7 **
Values have been expressed as mean±standard deviation.
p-values were measured with respect to day 2 measurements by paired
Students t-test.
* p<0.01, ** p<0.05.
Figure 2 Plot demonstrates the change in GZr at two time points
(t) i.e. week 4 and month 6 relative to the initial measurement at
day 2. Error bars indicate standard error.
Ghugre et al. Journal of Cardiovascular Magnetic Resonance 2011, 13(Suppl 1):P151
http://jcmr-online.com/content/13/S1/P151
Page 2 of 2


file:///data/remote/core/dit/data/Springer-OA/pdf/3fe/aHR0cDovL2xpbmsuc3ByaW5nZXIuY29tLzEwLjExODYvMTUzMi00MjlYLTEzLVMxLVAxNTEucGRm.pdf

Evolution of gray zone after acute myocardial infarction: Influence of microvascular obstruction

Abstract

Similar works

Full text

Available Versions

Crossref

Springer - Publisher Connector

Springer - Publisher Connector