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Presenter Disclosure Information
Robert E. Michler, M.D.
Influence of Left Ventricular Volume
Reduction on Outcome After Coronary
Artery Bypass Grafting With or Without
Surgical Ventricular Reconstruction
Financial Disclosure: NIH STICH Grants
NHLBI CT Surgery Network
Unlabeled/Unapproved Uses Disclosure: No
Influence of Left Ventricular Volume
Reduction on Outcome After Coronary
Artery Bypass Grafting With or Without
Surgical Ventricular Reconstruction
Robert E. Michler, Gerald M. Pohost, Krzysztof Wrobel,
Robert O. Bonow, Jan Pirk, Jae K. Oh,
Carmelo A. Milano, Patricia A. Pellikka,
Francois Dagenais, Thomas A. Holly,
Anne S. Hellkamp, Kerry L. Lee, Marisa Di Donato,
on behalf of the STICH Investigators
Late-Breaking Clinical Trial Update
American College of Cardiology
March 16, 2010
Introduction
 Ischemic cardiomyopathy resulting from progressive
LV volume increase due to CAD and anterior-apical
myocardial scar compromises clinical outcome.
 The objective of surgical ventricular reconstruction
(SVR) is to create a smaller left ventricle with a more
natural shape.
 One STICH (Surgical Treatment for Ischemic Heart
Failure) Trial specific aim was to determine if adding
SVR to CABG provided patient benefit beyond that of
CABG alone.
SVR Hypothesis Question
Does adding SVR to CABG in medically-treated
ischemic heart failure patients decrease death/cardiac
rehospitalization?
1000 patients randomized 2002-2006
CAD, EF ≤ 35%
Anterior akinesia/dyskinesia
amenable to SVR
Randomized
499
CABG only
501
CABG + SVR
Follow-up 99% complete at 48-months
Purpose
 To determine whether any magnitude of
postoperative change in LV ESVI identified a
subgroup of CABG + SVR patients who have
increased survival when compared to patients
undergoing CABG alone.
Analysis Design
 Cohort identified with paired core laboratory
studies of fair to excellent quality permitting
accurate assessment of end-systolic volume index
(ESVI).
 Individual preoperative and postoperative ESVI
illustrated for patient groups with:
1. ESVI <60 mL/m2
2. ESVI 60-90 mL/m2
3. ESVI >90 mL/m2
 Kaplan-Meier curves and hazard ratios calculated
on cohorts to examine for a differential effect of
adding SVR to CABG.
Paired Left Ventricular Studies Before and After
Operation in 979 SVR Hypothesis Patients
Operated Patients
N = 979
86 died before 4 months
Patients eligible for
paired study analysis
N = 893
16 NO baseline study
Patients with baseline
studies sent to core lab
N = 877
107 NO 4-month study
Patients with paired
baseline and 4-month
studies, N = 770
175 patients without
sent to core lab
sent to core lab
both paired studies of
fair to excellent quality
86 (9%) of operated patients
13 Specific reasons provided
for missing study
3 Unexplained
64 Telephone follow-up only
22 Technical problem
21 Unexplained
15 Pts with CMR assessment
14 Pts with SPECT assessment
146 Pts with ECHO assessment
Patients analyzed in this
report, N = 595
Observational cohort defined by ESVI taken from a Randomized population
Cumulative Distribution of 595 SVR Hypothesis Patients
by Baseline ESVI
Preoperative to Postoperative Change in ESVI by Operation Received
160 Patients with Baseline ESVI < 60 mL/m2
GROUP 1
Preoperative to Postoperative Change in ESVI by Operation Received
200 Patients with Baseline ESVI 60–90 mL/m2
GROUP 2
Preoperative to Postoperative Change in ESVI by Operation Received
235 Patients with Baseline ESVI > 90 mL/m2
GROUP 3
ESVI Change
Lowest to Highest
ESVI
Operation
Group 1
<60 ml/m2
(N=160)
CABG
(N=91)
Group 2
60-90 ml/m2
(N=200)
Group 3
>90 ml/m2
(N=235)
CABG+
CABG+
CABG+
SVR
CABG
SVR
CABG
SVR
(N=69) (N=111) (N=89) (N=118) (N=117)
% No Reduction
55%
43%
48%
20%
32%
21%
% >30% Reduction
23%
28%
20%
38%
24%
44%
Preop LVEF
Median
0.37
0.28
0.22
0.36
0.30
0.21
Postop LVEF
Median
0.38
0.31
0.25
0.40
0.35
0.27
Hazard Ratios and 95% Confidence Intervals
All-Cause Mortality
All Patients (n=1000)
(as randomized)
All Patients (n=979)
(by operation received)
Patients with Pre &
Post Surgery Studies
(n=595)
Patients Excluded
(n=384)
CABG+SVR Better
CABG Only Better
Hazard Ratios and 95% Confidence Intervals
All-Cause Mortality
Patients with Pre & Post
Surgery Studies (n=595)
Baseline ESVI > 90 ml/m2
(n=235)
Baseline ESVI 60- 90 ml/m2
(n=200)
Baseline ESVI < 60 ml/m2
(n=160)
CABG+SVR Better
CABG Only Better
Kaplan-Meier Estimates: Cumulative Risk of Death
Patients with Pre & Post Surgery Studies : Baseline ESVI ≤ 90 mL/m2
(n=360)
HR=0.59 (95% CI: 0.35 – 1.00; rank test: p=0.0475)
Total events (63): 20 in CABG+SVR and 43 in CABG Only
Kaplan-Meier Estimates: Cumulative Risk of Death
Patients with Pre & Post Surgery Studies : Baseline ESVI > 90 mL/m2
(n=235)
HR=1.24 (95% CI: 0.75 – 2.06; rank test: p=0.4071)
Total events (60): 33 in CABG+SVR and 27 in CABG Only
Hazard Ratios and 95% Confidence Intervals
All-Cause Mortality
Baseline ESVI ≤ 90 mL/m2
with Small or no Reduction
(n=180)
Baseline ESVI ≤ 90 mL/m2
with Large Reduction
(n=180)
Baseline ESVI > 90 mL/m2
with Small or no Reduction
(n=117)
Baseline ESVI > 90 mL/m2
with Large Reduction
(n=118)
CABG+SVR Better
CABG Only Better
Kaplan-Meier Estimates: Cumulative Risk of Death
Patients with Pre & Post Surgery Studies
Baseline ESVI > 90 mL/m2 and Small/or No Reduction in Post_Op ESVI
(n=117)
HR=1.54 (95% CI: 0.80 – 2.98; rank test: p=0.1950)
Total events (36): 17 in CABG+SVR and 19 in CABG Only
Small/or no reduction = change from baseline ESVI ≤ -23.7 mL/m2
Kaplan-Meier Estimates: Cumulative Risk of Death
Patients with Pre & Post Surgery Studies
Baseline ESVI > 90 mL/m2 and Large Reduction in Post_Op ESVI
(n=118)
HR=1.20 (95% CI: 0.51 – 2.80; rank test: p=0.6777)
Total events (23): 16 in CABG+SVR and 8 in CABG Only
Large reduction = change from baseline ESVI > -23.7 mL/m2
Limitations of Study
 Baseline LV volume and regional function data
were not available in every STICH patient.
 Secondary structural and hemodynamic variables
related to LV function, such as sphericity index or
mitral regurgitation, were not considered in this
analysis.
 Bias of investigators towards not sending
suboptimal postoperative studies cannot be
excluded.
Conclusions
1.
A broad range of baseline ESVI is represented among STICH patients.
2.
The postoperative ESVI decrease is significantly larger for CABG+SVR
patients.
3.
In patients with larger volumes, ESVI > 90 ml/m2, CABG alone resulted in
a substantial reduction in ESVI.
4.
Patients with preoperative ESVI values ≤ 90 ml/m2 trended toward benefit
from CABG + SVR, whereas patients with preoperative ESVI values
> 90 ml/m2 trended toward benefit from CABG alone.
5.
No threshold of ESVI at baseline, ESVI at 4 months postoperative or ESVI
volume change identified a patient group that benefited from adding SVR
to CABG.
6.
The post-op ESVI is the most important prognostic mortality measure.
Its prognostic importance is significant even after accounting for the
baseline ESVI or the pre-to-post change in ESVI.
Discussion Slides
Change in Regional Cardiac Function in 504 SVR Hypothesis Pts
Group 1: LVESVI < 60 mL/m2 (N = 129)
Preoperative
Postoperative
1
1
7
7
Dyskinesia
2
CABG
14
N = 70
3
2
9
3
9
6
2
13
8
16
14
11
5
3
9
17
10
4
4
1
1
7
7
17
15
12
6
2
13
8
16
14
11
5
3
9
12
17
15
10
10
4
4
6
16
11
15
10
13
14
N = 59
17
12
15
8
CABG + SVR
Normal
13
8
12
5
6
16
11
5
Change in Regional Cardiac Function in 504 SVR Hypothesis Pts
Group 2: LVESVI 60–90 mL/m2 (N = 170)
Preoperative
Postoperative
1
1
7
7
Dyskinesia
2
CABG
14
N = 96
3
2
9
3
9
6
2
13
8
16
14
11
5
3
9
17
10
4
4
1
1
7
7
17
15
12
6
2
13
8
16
14
11
5
3
9
12
17
15
10
10
4
4
6
16
11
15
10
13
14
N = 74
17
12
15
8
CABG + SVR
Normal
13
8
12
5
6
16
11
5
Change in Regional Cardiac Function in 504 SVR Hypothesis Pts
Group 3: LVESVI > 90 mL/m2 (N = 205)
Preoperative
Postoperative
1
1
7
7
Dyskinesia
2
CABG
14
N = 105
3
2
9
3
9
6
2
13
8
16
14
11
5
3
9
17
10
4
4
1
1
7
7
17
15
12
6
2
13
8
16
14
11
5
3
9
12
17
15
10
10
4
4
6
16
11
15
10
13
14
N = 100
17
12
15
8
CABG + SVR
Normal
13
8
12
5
6
16
11
5
Hazard Ratios and 95% Confidence Intervals
All-Cause Mortality
Patients with Pre & Post
Surgery Studies
(n=595)
Post-Op ESVI > 90 mL/m2
(n=150)
Post-Op ESVI 60- 90 mL/m2
(n=198)
Post-Op ESVI < 60 mL/m2
(n=247)
CABG+SVR Better
CABG Only Better