HEART FAILURE

1. DR. ANKIT JAIN
REVASCULARIZATION IN HEART
FALIURE

2. CORONARY ARTERY DISEASE
ACUTE CORONARY SYNDROME
Undergo revascularization procedures
Improved survival
Increased number of patients
with residual LV dysfunction
undergoing progressive LV
remodeling and congestive heart
failure

3.  In these patients, coronary revascularization may lead to
symptomatic and prognostic improvement
 These clinical benefits are accompanied by evidence of
reverse LV remodeling

4. In the early 1980s, Rahimtoola et al reviewed the results of
coronary bypass surgery trials and identified patients with CAD
and chronic LV dysfunction that improved by revascularization
CASS (coronary artery surgery study ) REGISTRY

5. Data from the coronary artery surgery study (CASS) registry
for patients with LVEF < 35% involved 651 patients.
• The five year survival was significantly better in surgical
patients (68%) than in the medical group (54%).
• The contrast was even more in patients with LVEF < 26% whose
five year survival was 63% with surgery, but 43% with medical
treatment

6. Thus came the concept of myocardial viability and
with it came the new terms such as hibernation and
stunning

7. VIABILITY
 Viable myocardium must have the following characteristics
1. The ability to generate ATP
2. have an intact sarcolemma, to maintain
ionic/electrochemical gradients, and
3. Have sufficient perfusion
4. The term “viable” implies nothing with regard to
contractile state

8.  There are two tissue states that exhibit sustained
contractile dysfunction despite meeting the three
criteria
 Stunned myocardium
&
 Hibernating myocardium.

9. MYOCARDIAL STUNNING
 First documented by Heyndrickx et al. in the mid- 1970s
 They concluded that brief periods of coronary occlusion
resulted in prolonged depression of myocardial function in
the ischemic zone.
 While regional electrograms return to normal within
seconds and the coronary flow restored rapidly, functional
derangement lasts for several hours.

10. Published October, 1975

11. Definition
 Brief period of ischemia
followed by restoration of
perfusion
 Subsequent LV
dysfunction of limited
duration
 Perfusion-contraction
mismatch
 Normal resting perfusion
 Decreased MBF reserve
Bolli R. Mechanism of myocardial stunning. Circulation 1990;82: 723–8.
Hearse DJ, Bolli R. Reperfusion induced injury: manifestations, mechanisms and clinical relevance. Cardiovasc
Res1992;26:101–8

12. PATHOGENESIS
There are 2 major hypotheses for myocardial stunning:
(1) a oxygen-free radical hypothesis and
(2) a calcium overload hypothesis
 Dysfunction may persist as long as 6 weeks post-insult
 Duration and severity of ischemia determine the duration of
post-ischemia/reperfusion dysfunction

13.  Normal cardiac contraction depends on the
maintenance of calcium cycling and homeostasis
across the mitochondrial membrane and sarcoplasmic
reticulum during each cardiac cycle.
 Brief ischemia followed by reperfusion-
accumulation of calcium and a partial failure of normal
beat to beat calcium cycling - damages Ca2+ pump
and ion channels of the sarcoplasmic reticulum.
 This results in the electromechanical uncoupling of
energy generation from contraction that characterizes
myocardial stunning

14. HIBERNATING MYOCARDIUM
 Is a state of persistently impaired myocardial function at
rest due to reduced coronary blood flow
 The physiology of hibernation involves reduced myocardial
blood flow, particularly to the subendocardium
 Resting blood flow may be reduced at rest but coronary
flow reserve is always reduced
Rahimtoola SH The hibernating myocardium Am Heart 1989;117:211-221

15. Ultra structural changes
Circulation1998;98:1151-1156
 Alteration of structural
proteins & metabolism to a
more fetal form - Smart heart
hypothesis
 Apoptosis and fibrosis
 Disorganization of the
cytoskeleton
 Loss of myofilaments
 Occurrence of large areas
filled with glycogen
 Ionic instability

16. Stenosis and flow relationship
 Coronary stenosis between
40 – 50% percent does not
alter resting MBF and
coronary flow reserve
 Between 40 and 80 percent
stenosis, resting MBF is
normal, but MBF reserve
flow is diminished
 A stenosis greater than 80
percent is associated with a
reduction in resting blood
flow
Gould KL, Lipscomb K, Hamilton GW. Physiologic basis for assessing critical coronary stenosis.
Instantaneous flow response and regional distribution during coronary hyperemia as measures of coronary
flow reserve. Am J Cardiol 1974;33:87–94.

17.  Recent data suggest that myocardial blood flow in hibernation
may not be decreased at rest to an extent that would account for
the degree of cardiac dysfunction
 It is now believed that hibernating myocardium is a
manifestation of repeated myocardial stunning as a result of
impaired coronary flow reserve
 In severe coronary disease, the limited flow reserve causes
repeated myocardial ischemia  repeated stunning 
Hibernation
 Gerber BLJL, Vanoverschelde JL, Bol A, et al. Myocardial blood flow, glucose uptake and recruitment of inotropic
reserve in chronic left ventricular ischaemic dysfunction

19. SUSPECT HM
 Unstable and stable angina
 Acute myocardial infarction
 Left-ventricular dysfunction +_congestive heart
failure
 Anomalous left coronary artery from the
pulmonary artery

20. Myocardial viability
 Nearly 50-60% of pts with Ischemic HF have substantial
viable myocardium
 Substantial viable myocardium means presence of viability
in at least 25% of LV myocardium ( ≥4 segments)
 Revascularization in such patients is likely to lead to a
significant ↑ in LVEF (by ≥5%)
Schinkel et al. Am J Cardiol 2001;88:561-4
Bax et al. J Am Coll Cardiol 1999;34:163-9

21. Why should viable myocardium be
Revascularized?
 Improvement of regional and global LV systolic function
 Remodeling is reversed
 Survival is increased
 Decrease of the composite of myocardial infarction, heart
failure, and unstable angina
Ferrari R. Myocardial hibernation. An adaptive phenomenon? In: Yellon DM, Rahimtoola SH, Opic LH, New Ischemic
Syndromes. New York, NY: Authors Publishing House, 1997:204–14
Rahimtoola SH, La Canna G, Ferrari R. Hibernating myocardium: another piece of the puzzle falls into place. J Am Coll Cardiol
2006;47:978–80.

22. The role of viability testing
 Observational series suggest that viability testing is useful to identify
patients likely to benefit from revascularization
 In a meta-analysis of 24 studies of viability testing in 3088 patients
with CAD and systolic dysfunction (Tl-201 SPECT (n- 6) FDG-PET (n-11), or DbE (n
- 8) to assess HM)
 In Patients with viability 1-year mortality was 16% in the OMT patient
and 3.2% in patients who had revascularization
 There was no difference in mortality among the patients who did not
had viability
Allman KC, Shaw LJ, Hachamovitch R, Udelson JE: Myocardial viability testing and impact of revascularization on
prognosis in patients with coronary artery disease and left ventricular dysfunction: A meta-analysis. J Am Coll Cardiol
39:1151, 2002.)

23. Allman KC, Shaw LJ, Hachamovitch R, Udelson JE: Myocardial viability testing and impact of
revascularization on prognosis in patients with coronary artery disease and left ventricular
dysfunction: A meta-analysis. J Am Coll Cardiol 39:1151, 2002.)

24. RESULTS
 Excess death in the population with hibernating
myocardium is to a large extent sudden, presumably
arrhythmic death
 Scar formation and a reduction and inhomogeneity of
connexin 43 expression in HM may contribute to
alterations in electrical impulse propagation and reentry
 Isolated myocytes from HM are hypertrophied and have
striking prolongation of the action potential and EAD
 Bito V, Heinzel FR et al. Cellular mechanisms of contractile dysfunction in hibernating
myocardium. Cellular remodeling in hibernation.Circ Res 94:

26. How much of LV should be viable?
 Target is to improve LV function by at least 5%
 25% of the LV should be viable using DSE
 38% using conventional nuclear medicine and PET
Bax JJ, Maddahi J, Poldermans D, Elhendy A, Schinkel A, Boersma E, Valkema R, Krenning EP, Roelandt JR, van der Wall
EE. Preoperative comparison of different noninvasive strategies for predicting improvement in left ventricular function after
coronary artery bypass grafting. Am J Cardiol. 2003;92:1– 4

27. Techniques to assess myocardial
viability

28. ECG and viability
 60% of regions with Q waves have viable myocardium as
detected by imaging techniques
 ST-segment elevation at rest in leads with Q waves is
associated with non viable scarred myocardium
 Exercise-induced Q wave prolongation is demonstrated in
patients with recent MI who shows viability
Assessment of residual myocardial viability in regions with chronic electrocardiographic Q-wave infarction. Am Heart J 2002;144:865–869
Bodi V, Sanchis J, Llacer A et al. ST-segment elevation in Q leads at rest and during exercise: relation with myocardial viability and left
ventricular remodelling within the first 6 months after infarction. Am Heart J 1999;137:1107–15.

29. CONTD..
 ST elevation developing during exercise or dobutamine
stress is a marker of maintained viability
 The combination of ST elevation and reciprocal ST
depression increases the accuracy for detection of viable
myocardium
 Inducible perfusion abnormalities assessed by SPECT have
been seen
 In 94% of patients with exercise- induced ST elevation
 In 50% with pseudonormalisation of the T wave but
without ST elevation

30. 2D Echo
Do improve
 LV end-diastolic wall
thickness ≥ 0.5 to 0.6
cm
 Hypokinetic rather than
akinetic or dyskinetic
Don t improve
 LV (end-diastolic volume
greater than twice the
upper limit of normal)
 The involvement of 4
ventricular wall segments
by scarring
Rahimtoola et al. J Am col cardio : c a r d i o v a s c u l a r i m a g i n g , 1 (4), 2 0 0 8 : 5 3 6 – 5 5

31. DSE
 The augmentation of contractility (contractile reserve) in
response to dobutamine stress is the basis for the use of
stress echocardiography
 Dysfunctional myocardium that is able to show a transient
improvement in systolic function in response to dobutamine
(contractile reserve) is considered viable

32. Predictive value of DSE
 E/o myocardial viability on low dose DSE is a strong predictor
of both long term survival and functional recovery in Ischemic
HF patients
 Biphasic response has highest predictive value
 Segments with a biphasic response has a specificity
and sensitivity of 80% to 90% for prediction ofglobal
functional recovery
Curr Probl Cardiol 2001;26:141–86

33. Myocardial Contrast echo
 Myocardial perfusion by CE is evaluated qualitatively, and
segments visually classified as :
 Viable (normal or patchy perfusion )
Or
 Nonviable ( absent perfusion)
 Micro vascular density and the capillary area correlates
inversely with the extent of fibrosis
 MCE has a primary role in assessing the quality of
reperfusion following STEMI (No reflow)
Heart 2003;89:139–144
Circulation 2002;106:950–6

34. MCE for prediction of viability
 Sensitivity and specificity of 89% and 51% to predict
functional recovery
 High NPV for recovery of function and residual viability
 ≥ 3 viable segments on MCE: high likelihood of
improvement in global LV function post-revascularization
J Am Coll Cardiol 1997;29:985–93

35. 201Thallium SPECT
 The most widely used method for assessing myocardial
viability
 Initial uptakedependent on myocardial blood flow
 Retention 3 to 4 hours after injection is an active, energy-
requiring process that is a function of cell membrane
integrity and tissue viability

36. Markers of viability on Thallium
 Reversible defects on rest-redistribution imaging
 Rest-redistribution, an uncommon observation, is highly
predictive of hibernation when seen
 The recommended SPECT imaging is stress-redistribution-
reinjection It provides information about viability and
ischemia
Lomboy CT, Schulman DS, Grill HP et al. Rest-redistribution thallium-201 scintigraphy to determine myocardial
viability early after myocardial infarction. J Am Coll Cardiol 1995;25:210–7.
Marin Neto JA, Dilsizian V, Arrighi JA et al. Thallium reinjection demonstrates viable myocardium in regions with
reverse redistribution. Circulation 1993;88:1736–45.

37. Technetium-99m sestamibi
 Emits higher energy
photons
 Has better tissue
penetration
 Shorter T1/2
 Uptake depends on both
perfusion and viability
 No redistribution
 The most widely reported
technetium agent is Tc-
99m-sestamibi

38. Markers of viability
 Viability is considered to be present when in dysfunctional
segments:
 tracer uptake is normal or
 shows reversible defect or
 mild-to-moderate fixed defects (>50-60% of normal region)
 Pretreatment with nitrates may enhance the accuracy for
detection of viability
Sciagra R, Bisi G et al J Nucl Cardiol 1996;3: 221–30.

39. Prediction of outcome
 Overall sensitivity - 81%, specificity - 66%, PPV-71%,
and a NPV- 77% in predicting post-revascularization
improvement of regional ventricular function
Curr Probl Cardiol 2001;26:141–86

40. Nuclear imaging Vs DSE
Bax et al. Curr Probl Cardiol. 2001;26:141-188

41. Limitations of nuclear scans
 The relatively poor spatial resolution
 Detection of subendocardial scar is difficult
 False negative in TVD with uniform ↓ in perfusion ( global
ischemia effect)
 Radiation burden

42. Positron Emission Tomography
 Allows simultaneous assessment of perfusion and metabolic
status of myocardial tissue
 Imaging with high spatial and temporal resolution
 Estimations of myocardial perfusion have been performed with
13NH3 and H215O
 Metabolism by FDG
 Can quantify MBF

43. FDG- PET
 In the fasting state, the heart predominantly uses free
fatty acids as a source of fuel
 During conditions of ischemia, the myocyte switches
to glucose as its predominant source of energy
 ↑ glycogenolysis
 ↑ glycolysis
 ↓ mitochondrial metabolism
 ↓ FFA uptake

44. FDG- PET
 As there should be no uptake of glucose by infarcted
myocardium—which is metabolically inert—nonviable
myocardium will appear as a region of low-FDG
concentration
 In areas of reversibly injured myocardium, glucose
utilization is normal and even above normal
 Thus, stunned or hibernating myocardium may be
indistinguishable from normal tissue in an FDG PET image

45. PET Classification of Dysfunctional
Myocardium
Tissue type Perfusion Metabolism Recovery with
revascularization
Stunned Normal Normal Yes
Hibenating Reduced Increased relative
to perfusion
Yes
Transmural
infarction
Reduced Reduced No
Non transmural
infarction
Partially reduced Partially reduced Varies
Curr Opin Cardiol 21:464–468 2001

46. PET in Viability assessment
 Less radiation burden
 Significantly higher sensitivity than Tl-201 rest-
redistribution imaging
 Spatial resolution superior to SPECT but inferior to MRI
 Meta-analyses suggest sensitivity around 90% and
specificity of 60% to 70%

47. CMR
 Most promising modality
 Provides information on anatomy, function and perfusion,
with high spatial resolution
 The minimum amount of myocardium that can be imaged is
1 g with a spatial resolution of 2 mm
 Reliable and accurate assessment of myocardial scar burden
and contractile reserve by CMR Overall sensitivity and
specificity of 81% and 80%

48. LGE

49. DEMRI-Bright means dead
 Most promising MR
parameter for viability
 Demonstrates nonviable
tissue as
"hyperenhanced"or
bright signal-
 DE-MRI assesses
viability as a continuum
based on transmural
thickness of
hyperenhancement
% of
enhancement
<75%
<25%-
viable+++
25-75%--
continuum
>75% Scar
Jonathan W. Weinsaft et al Magn Reson Imaging Clin N Am 15 (2007) 505–525

50. ADVANTAGE OF CMR
• A major advantage of DE-MRI is that it can visualize
the transmural extent of both alive (viable) and dead
(nonviable) myocardium

51. Low dose Dobutamine stress MRI
 DS MRI is less sensitive but more specific with respect to
recovery of contractile function after revascularization
 sensitivity and specificity of dobutamine MRI for the
diagnosis of myocardial viability is 81 and 95%.

52. MODALITY
SENSITIVITY (%)
MEAN (95% CI)
SPECIFICITY (%)
MEAN (95% CI)
Dobutamine
echocardiography
76 (72-80) 81 (77-84)
Delayed enhancement by
MRI
97 (91-100) 68 (51-85)
FDG PET 89 (85-93) 57 (51-63)
SPECT 89 (84-93) 68 (61-75)
COMPARISION OFDIFFERENT TECHNIQUES
Circulation 117:103, 2008.

53. REVASCULARIZATION IN ICM
 Revascularization in ICM refers to revascularization of not
only of dysfunctional but viable myocardium but also of
remote, normally contracting myocardium (at rest) but
subtended by flow limiting stenosis

54. REVASCULARIZATION IN HM
 Functional recovery after revascularization is more
prolonged and dependent on new protein synthesis and
myocyte repair
 In the absence of revascularization, repetitive ischemia may
progress to myocyte necrosis or apoptosis and fibrosis
indicating that hibernating myocardium is not fully adapted
to chronic hypo perfusion
 Consequently, if revascularization is to succeed, it must be
applied early

55. EARLY REVASCULARIZATION
 When the dyskinetic region occupies more than 10% of the
total myocardial mass , the left ventricle progressively
enlarges
 This causes subendocardial ischemia in the remote
myocardium and progressive ventricular remodeling occur
 After severe ventricular dilitation revascularization is less
likely to be successful even in the presence of HM
 Revascularization should be done early before irreversible
LV remodeling and myocardial fibrosis occur

56. CONTD..
 LVEDD more then 70 mm predicts poor prognosis after
revascularization
 It indicates the presence of multiple segments of scarred
myocardium
 If such degree of LV remodeling and these ventricular
dimensions are present , even if viability is documented,
revascularization is not improve clinical outcomes
Rahimtoola SH et al. Chronic ischemic left ventricular dysfunction: from pathophysiology to imaging and
its integration into clinical practice. JACC Imaging. 2008

58. REVASCULARIZATION
 Revascularization is associated with increased risk in
patients with low LVEF, And not all patients with ischemic
cardiomyopathy show improvement in contractile function
 So a careful selection of patients who may benefit from
revascularization procedures appears to be warranted
 The evidence supporting the clinical benefit of surgical
coronary revascularization is based on observational data

59. Duke Cardiovascular Disease
Databank
 They reported 25-year experience of 1391 patients with
systolic dysfunction and ischemic heart disease
 1052 patients were treated medically
 339 underwent CABG
 CABG-treated patients had a significantly lower mortality
 The survival advantage was present regardless EF, age or
NYHA class

60. RESULTS

61. Results for 1, 2 or TVD

62. Subgroup analysis

63. Surgical Treatment for Ischemic
Heart Failure Trial (STICH)
 In patients with HF, LVD and CAD amenable to surgical
revascularization, CABG added to intensive MED will
decrease all-cause mortality compared to MED alone
INCLUSION CRITERIAS
• LVEF ≤ 35%, CAD suitable for CABG
• MED eligible
 Absence of left main CAD as defined by an
intraluminal stenosis of ≥ 50%
 Absence of CCS III angina or greater
(angina markedly limiting ordinary activity)

64. RESULTS
 1212 Patients were randomized
 CABG 610
 Medical Therapy 602
• In patients randomized to STICH, there was no statistically
significant difference in all-cause mortality between
medical therapy alone and medical therapy with CABG
• Although CABG reduces cardiovascular mortality and
morbidity compared to medical therapy alone

65. N Engl J Med 2011; 364:1607-1616

66. LIMITATIONS
 The mean age was just 60 years
 60% predominantly suffered angina pectoris and, 60% were
in NYHA class I or II HF means ,patients were less sick
 The clinical HF was not necessary for trial enrolment
 Trial excluded patients with significant left main stem
disease
 Intention-to-treat analysis did not demonstrate a beneficial
impact of revascularization, the as-treated analysis did
show significant benefit for CABG over OMT
 A 19% reduction in cardiovascular mortality was observed

68. RESULTS
 Inclusion criteria was LVEF <35%, CAD
amenable to CABG and no left main stenosis
≥50%
 763 patients were included for propensity score
analysis including 624 who received OMT and
139 CABG
 Risk-adjusted mortality rates at 5 years of 46% for
OMT versus 29% for CABG, and the survival
benefit of CABG over MED continued through 10
years follow-up

69. Unadjusted Kaplan Meier Rate
Estimates of Time to Death

70. PARR2
 The lack of randomized controlled trials (RCT) of viability
testing was addressed by the PARR-2 trial
 PARR-2 stratified patients with severe LV systolic
dysfunction randomized to
 PET-guided management (n = 218) vs.
 Without PET (where an alternative test could be considered
[n = 212])
 At 1 yr demonstrated no significant difference in the
composite primary outcome of cardiac death, MI or
recurrent hospitalization between the 2 arms.

72. LIMITATIONS
 PARR-2 had lower adherence to PET-guided
recommendations, which may have reduced the ability to
detect a difference in the primary outcome
 When only patients adhering to PET-guided
recommendations were included, the PET adherence group
had significantly better outcome than the standard care
group

74. OBJECT
 Trial assess the interaction between myocardial viability
and survival in randomized patients who were eligible for
medical management alone and eligible for CABG

75. Patients with viability tests
Patients
without
myocardial
viability
Patients with
myocardial
viability
CABG
50.1%
CABG
47.4%
MED
49.9%
MED
52.6%
601
487
243 244
114
60 54

76. RESULTS
 A total of 17 of 487 patients with viability (37%) and 58 of
114 patients without viability (51%) died but after
adjustment for other baseline variables, this association
with mortality was not significant
 Trial concluded that in patients with CAD and LV
dysfunction, assessment of myocardial viability does not
identify patients who will have the greatest survival benefit
from adding CABG to aggressive medical therapy

77. LIMITATIONS
1. Analysis limited to SPECT and DE, not PET or c-MRI
2. It was not a true randomized assessment as optional
viability testing was done upon clinical decision
3. It is highly likely that patients without HM were not
enrolled (only 19% of STICH trial patients had no
demonstrable HM)

78. CONTD..
 Patients who underwent viability testing had significantly
greater LV dysfunction, LV dilatation, and incidence of
previous AMI
 It is known that patients with very severely remodelled
ventricles are less likely to benefit from revascularization
 This is therefore a crucial difference between the groups
and made it more likely that viability testing would appear
ineffective

79. CONTD..
 It is possible that the advances in medical and device
therapy have markedly reduced the added benefit o
revascularization, such that it is difficult to demonstrate
further improvement in clinical outcomes
 Benefit of CABG may not be related to revascularization of
viable segments but rather to revascularization of
potentially ischemic segments

81. RESULTS
 Trial Prospectively evaluated survival of 144 consecutive
patients (130 males, age 65 11 years) with CAD and LV
dysfunction (EF 24 7%) undergoing DE-CMR
 86 patients underwent complete revascularization (79
CABG/ 7 PCI)
 58 patients remained under medical treatment
 Significant viability is present if 4 dysfunctional segments
have <50% transmural hyperenhancement

82. RESULTS
 In patients with viability, medical therapy was associated
with a 4.6-fold increased risk of death compared with those
who were completely Revascularized
 There was no significant difference in survival with
medical therapy versus revascularization in patients without
viability
 In this study also the survival was better in patients with
non viable myocardium then with viable when both was
treated by OMT

84. WHY SO MUCH DISCREPANCY
 Structural changes occur, most prominently in
dysfunctional regions but also in remote, normally
contracting segments .
1. Reductions in microvessel density and cross-sectional
area
2. Depletion of myocyte contractile elements
3. Collagen replacement within the extracellular matrix
which may be of varying severity and reversibility
The extent of these changes likely affect the success of
revascularization
Rahimtoola SH, Dilsizian V, Kramer CM, Marwick TH, Vanoverschelde JL. Chronic
ischemic left ventricular dysfunction: from pathophysiology to imaging and its integration
into clinical practice. J AmColl Cardiol Img 2008

85. CONTD..
 Trans mural extent of DE assesses only 1 aspect of this complex
process, that of scar/collagen replacement
 So its accuracy in predicting functional recovery when there is
intermediate extents of transmurality is reduced
 The ability of CMR to assess resting perfusion and CFR
Myocardial energetics, and quantitative regional wall motion
using tissue tagging should be capitalized
 Because there may be better predictive value in assessing
multiple aspects of viability in a tiered approach rather than 1
component

86. CONTD..
 The other viability imaging also suffer from lack of
accuracy in predicting recovery even after
showing presence of viable myocardium probably
because of these reasons

87. LVEF NOT INCREASED POST
SURGERY
 Several studies have shown that LVEF improved
significantly ( =5%) after revascularization in 60% of
patients (range, 38% to 88%)
 Hence, resting LVEF does not always improve after
revascularisation despite the presence of substantial
myocardial viability
 Patients with severly dilated ventricles and extensive
fibrosis are less likely to improve LVEF after
revascularization
 Pagano D, Fath-Ordoubadi F, Beatt KJ, Townend JN, Bonser RS, Camici PG. Effects of coronary revascularisation on
myocardial blood flow and coronary vasodilator reserve in hibernating myocardium. Heart. 2001

88. OTHER
1. Incomplete revascularization
2. Viable myocardium may be juxtaposed to
regions with extensive scarring and unable to
respond to revascularization because of
tethering
3. There might be new perioperative myocardial
necrosis in regions that were viable prior to
revascularization
4. Too early assesment

89. RESTING VS. STRESS LVEF

90. TIME COURSE OF RECOVERY
 The time interval between revascularization and
assessment of LV function at follow-up ranged from 2 to 6
months
 Stunned segments :
 2/3rd - early contractile recovery (≤3 mths)
 1/10th show late improvement (≥1 yr)
 Hibernating segments
 1/3rd - early improvement
 2/3rd show late recovery
Bax et al. Circulation 2001;104 Suppl 1:I314–8

92. RESULTS
 104 consecutive patients who underwent LVEF assessment
CABG,
 68 had improvement in LVEF (>5% increase)
 36 had no significant change.
 The two groups had similar postoperative improvement in
angina and heart failure scores, and there was no difference
in cardiovascular mortality with a mean follow-up of
32months

93. Potential Mechanisms
 Subendocardial scar can prevent systolic thickening at rest,
but revascularization of the mid-myocardial and epicardial
layers—which maintains their viability—helps prevent scar
expansion
 So even if LVEF is not increased the absence of further
cavity dilatation and improved LV geometry is in fact a
benefit of revascularization
 Senior R, Lahiri A, Kaul S. Effect of revascularization on left ventricular remodeling in patients
with heart failure from severe chronic ischemic left ventricular dysfunction. Am J Cardiol 2001

94. Potential Mechanisms
 Revascularized myocardium may limit infarct expansion
and ventricular dilation by providing a scaffolding which
supports the surrounding necrotic myocardium and reduces
myocardial compliance
 These mechanisms may also improve diastolic function and
even reduce dynamic mitral regurgitation
 Revascularization of ischemic myocardium bordering
endocardial scar may reduce the incidence of ventricular
arrhythmias

95. PCI IN LV DYSFUNCTION
 Data is limited for PCI
 A meta-analysis of studies utilizing PCI in patients
with ejection fraction ≤ 40%) was done to determine
in-hospital and long-term (≥ 1 year) mortality
 4766 patients from 19 studies were included in this
meta-analysis
 The mean LVEF was 30%
 The in-hospital mortality using random-effects model
was 1.8%
 The long-term mortality was 15.6%

96. CONTD..
 The relative risk using the random-effects model (PCI vs.
CABG) was 0.98
 So the PCI among patients with left ventricular
dysfunction is feasible with acceptable in-hospital and
long-term mortality and yields similar outcomes to CABG
 Kunadian, Vijayalakshmi et al .Percutaneous coronary intervention among patients with left
ventricular systolic dysfunction: a review and meta-analysis of 19 clinical studies Coronary
Artery Disease November 2012 - Volume 23 - Issue 7 - p 469–479

97. PCI VS CABG
 Patients with reduced LVEF <50%, who had undergone
PCI with DESs (n = 402) or CABG (n = 551) were enrolled
in a retrospective, observational registry
 The primary outcome was all-cause death
 The median follow-up duration was 32 months
Jeong Hoon Yang et al.Long-Term Outcomes of Drug-Eluting Stent Implantation Versus Coronary Artery
Bypass Grafting for Patients With Coronary Artery Disease and Chronic Left Ventricular Systolic
DysfunctionAmerican Journal of Cardiology
Volume 112, Issue 5 2013

98. RESULTS
 All-cause death occurred in 81 patients (20.1%) in the DES group and
98 patient (17.8%) in CABG
 Long-term cumulative rate of death was not significantly different
between the 2 groups (DES vs CABG 21.3% vs 19.1%)
 Rate of major adverse cardiac and cerebrovascular events (35.5% vs
24.1%, was higher in the DES group than the CABG group
 This was driven by the higher incidence of repeat revascularization in
the DES group (11.3% vs 4.3%)

 In conclusion, DES implantation provides comparable long-term
clinical outcomes, except for repeat revascularization, to CABG in
patients with CAD and LV dysfunction

99. ESC GUIDELINES 2010

100. PRDOMINENT HEART FALIURE

101. ACC 2013

103.  Rahimtoola SH, Dilsizian V, Kramer CM, Marwick TH, Vanoverschelde JL. Chronic ischemic left ventricular dysfunction: from
pathophysiology to imaging and its integration into clinical practice. J AmColl Cardiol Img 2008

104. CONCLUSION
BENEFITS OF REVASCULARIZATION DEPENDS
ON
1. The presence and magnitude of stress induced
ischemia
2. The stage of cellular degeneration within viable
myocardium
3. The degree of LV remodeling
4. Timing and success of revascularization
procedure
5. Adequacy of the target coronary vessels, can
affect the functional outcome after
revascularization

105. CONCLUSION
 Revascularization should be done early before irreversible
myocardial injury occur
 In patients with ICMP with predominant heart failure
symptoms viability assessment is essential before
Revascularization
 More detailed viability studies are needed for accurate
prediction of benefits of revascularization in ICMP
 Benefits of revascularization are not always associated with
improved LVEF
 Survival of patients with HM treated by MM is worse then
similar pts. With non viable treated by MM

106. THANK YOU