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Dysfunctional but viable
myocardium
Ischemic heart disease assessed by MRI and SPECT
Martin Ugander, MD
Department of Clinical Sciences, Lund
Department of Clinical Physiology
Lund University
Supervisor:
Co-supervisor:
Håkan Arheden, MD, PhD
Clinical Physiology, Lund
Peter Cain, MBBS, PhD
Wesley Heart Clinic, Brisbane, AU
Funding:
• Swedish Research Council
• Swedish Heart Lung Foundation
• Faculty of Medicine at Lund University
• Region of Scania
Aim
• To further elucidate the pathophysiology
of dysfunctional but viable myocardium
in patients with ischemic heart disease.
Outline of Studies
• Study I - Method for quantitative MRI & SPECT
• Study II - Wall thickening vs. Infarct transmurality
• Study III - LVEF vs. Infarct size
• Study IV - Time course of perfusion & function
after revascularization
Study I
Quantitative polar representation of left
ventricular myocardial perfusion, function and
viability using SPECT and cardiac magnetic
resonance: initial results
Cain PA, Ugander M, Palmer J, Carlsson M,
Heiberg E, Arheden H.
Clin Physiol Funct Imag 2005 (25) 215-222
Background
• Clinical management of CAD involves
complex assessment of the extent and
severity of changes in function,
perfusion and viability.
• No adequate research tools for
quantitative assessment exist.
Aims
• To explore the feasibility of integrative
quantitative representation of LV
perfusion, function and viability in polar
plots.
• To determine agreement between visual
scoring and quantitative measures.
Methods
• 10 patients scheduled for CABG
– rest/stress SPECT
– Cine and delayed enhancment CMR
• Quantification with in-house software
• Comparison with visual scoring using
Kendall’s coefficient of concordance (W)
Methods
Results
Results
Kendall’s W: 1.0 (p<0.001)
0.85 (p<0.001)
Conclusions
• Side-by-side quantitative polar
representation of LV perfusion, function
and viability is feasible and may aid in
the complex assessment of these
parameters.
• The agreement between quantitative
measurement and visual scoring was
very good.
Study II
Infarct transmurality and adjacent segmental
function as determinants of wall thickening in
revascularized chronic ischemic heart disease
Ugander M, Cain PA, Perron A, Hedström E,
Arheden H.
Clin Physiol Funct Imag 2005 (25) 209-214
Background
• Regional LV function in patients with
IHD may be influenced by many factors.
Aims
• To explore how regional wall thickening
in patients with chronic IHD is affected
by both infarct transmurality and the
function of adjacent segments.
• To compare with results from healthy
subjects.
Methods
• 20 patients
– 6 months after revascularization
– Cine CMR
– Delayed enhancement CMR
• 20 matched controls
– Cine CMR
Multivariate analysis of
parameters contributing to
wall thickening
t
Infarct transmurality
-4.5
Number dysf. adjacent seg. -22.9
p
<0.001
<0.001
Conclusion
• The number of dysfunctional adjacent
segments is a greater determinant than
infarct transmurality on regional wall
thickening.
• Infarction is difficult to assess by resting
function alone.
• DE CMR is an important tool in this
setting.
Study III
A maximum predicted left ventricular ejection
fraction in relation to infarct size in patients with
ischemic heart disease
Ugander M, Ekmehag B, Arheden H.
Submitted
Background
• An understanding of the relationship
between LVEF and infarct size is
important when assessing the potential
benefit of revascularization in patients
with IHD.
Aims
• To explore the relationship between
LVEF and IS.
• To determine a maximum predicted
LVEF for a given IS.
Methods
• 297 patients clinically referred for
viability assessment by CMR
• LVEF
• Infarct size (% LVM)
Methods
LVEF (%)
A
C
θ
B
Infarct size (%LVM)
Patient characteristics (IHD)
Distribution of infarctions
Distribution of number of
coronary artery vessel
territories
Results
Cine
Contrast
2ch
4ch
LVEF=29%
IS=36%
Cine
Contrast
2ch
4ch
LVEF=25%
IS=6%
Conclusions
• LVEF cannot be used to estimate IS.
• IS cannot be used to estimate LVEF.
• LVEF can be used to estimate a
maximum predicted IS.
• IS can be used to estimate a maximum
predicted LVEF.
Study IV
Influence of the presence of chronic nontransmural myocardial infarction on the time
course of perfusion and functional recovery after
revascularization.
Ugander M, Cain PA, Johnsson P, Palmer J,
Arheden H.
Manuscript
Background
• The time course of recovery of LV
function and perfusion after
revascularization is not fully understood.
Aims
• To study the effect of presence of
infarction on the time course of recovery
of perfusion and function after elective
revascularization.
Methods
• 15 patients (inclusion ongoing)
– first time elective CABG (n=13) or PCI (n=2)
• Imaging
– rest/stress SPECT
– cine and delayed enhancement CMR
– Before revasc., 1 & 6 months after revasc.
Patient characteristics
•
•
•
•
•
•
14 men, 1 woman
mean age 68 years (range 52-84)
3VD n=6
2VD n=6
1VD n=3
LVEF = 49  10%
Distribution of infarct
transmuralities
Conclusions
• Dysfunctional segments without
infarction improved both perfusion and
function at 1 month.
• Segments with infarction showed
improved perfusion at 1 month and
improved function at 6 months.
• This may reflect more severe ischemic
burden in segments with infarction.
Summary
• Study I - Method for quantitative MRI & SPECT
• Study II - Wall thickening vs Infarct transmurality
• Study III - LVEF vs Infarct size
• Study IV - Time course of perfusion & function
after CABG
Conclusion
• It is important to perform quantitative
assessment of function,perfusion and
viability in combination when studying
the pathophysiology of dysfunctional but
viable myocardium in IHD.
www.med.lu.se/cmr
Bo Hedén, MD PhD
Ann-Helen Arvidsson, tech
Henrik Engblom, MD, PhD-student
Håkan Arheden, MD PhD
Christel Carlander, tech
Karin Markenroth, PhD
Marcus Carlsson, MD, PhD-student
Martin Ugander, MD, PhD-student
Erik Hedström, PhD
Einar Heiberg ,PhD
Henrik Mosén, MD, PhD
Erik Bergvall, MSc, PhD-student
The ischemic cascade
Mahrholdt et al
2005 Eur Heart J