Transcript Surgical Repair Is the Treatment of Choice for Native Aortic

T h e H e rma H e a r t C e n te r, C h i l d re n ’ s H o s p i t al o f W i s c o n s i n
The Borderline Left Ventricle: What is
it? Recruit it or Forget it?
American Association for Thoracic Surgery
Seattle, WA, April 25, 2015
James S. Tweddell, MD
Children’s Hospital of Wisconsin.
Professor of Surgery and Pediatrics,
Cardiothoracic Surgery,
Medical College of Wisconsin.
Disclosures
• Financial disclosures –
Consultant for CorMatrix
• Off label use of drugs or
devices -None
The borderline left ventricle
Congenital malformations with a
moderately hypoplastic left ventricle in
which intervention is required in the
neonatal period
• Critical aortic stenosis (HLHS AS/MS)
• Lesions where coarctation/arch
hypoplasia is a constant finding with or
without VSD
 Coarctation with non-apex forming right
ventricle
 Hypoplastic left heart complex
Critical aortic stenosis
• One of first lesion to be studied
• How small is too small?
Kearney DL Sem Cardiothorac Vasc Anesth 2013
Aortic valve stenosis
• Risk factors for poor outcome
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1981-Latson – LV cross-sectional area <1.6cm2
1983 Mocellin – LVEDV < 80% normal and EFE
1983 Keane – LVEDV < 20ml/m2
1986 Gundry – EFE, LVEDP >26mmHg, LVEF < 42%
1987 Pelech – Pre-op shock/CHF, cardiomegaly, RVH, mitral
valve <11mm, Ao valve < 6mm, LVEDP > 20mmHg, LVEF < 40%
1988 Hammon- LVEDV < 20ml/m2 and MPAP > 50mmHg
1989 Zeevi – LVEDV < 60-80%
1990 Karl – LVEDV < 60%, non-apex forming LV
1991 Leung-mitral valve <9mm, LV-aortic junction<5mm
1991 Parson- LV cross-sectional area <2.0cm2, LVEDV <
20ml/m2, LVEDD <13mm
Aortic valve stenosis
• Risk factors for poor outcome
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1981-Latson – LV cross-sectional area <1.6cm2
1983 Mocellin – LVEDV < 80% normal and EFE
1983 Keane – LVEDV < 20ml/m2
1986 Gundry – EFE, LVEDP >26mmHg, LVEF < 42%
1987 Pelech – Pre-op shock/CHF, cardiomegaly, RVH, mitral
valve <11mm, Ao valve < 6mm, LVEDP > 20mmHg, LVEF < 40%
1988 Hammon- LVEDV < 20ml/m2 and MPAP > 50mmHg
1989 Zeevi – LVEDV < 60-80%
1990 Karl – LVEDV < 60%, non-apex forming LV
1991 Leung-mitral valve <9mm, LV-aortic junction<5mm
1991 Parson- LV cross-sectional area <2.0cm2, LVEDV <
20ml/m2, LVEDD <13mm
Aortic valve stenosis
• Risk factors for poor outcome
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1981-Latson – LV cross-sectional area <1.6cm2
1983 Mocellin – LVEDV < 80% normal and EFE
1983 Keane – LVEDV < 20ml/m2
1986 Gundry – EFE, LVEDP >26mmHg, LVEF < 42%
1987 Pelech – Pre-op shock/CHF, cardiomegaly, RVH, mitral
valve <11mm, Ao valve < 6mm, LVEDP > 20mmHg, LVEF < 40%
1988 Hammon- LVEDV < 20ml/m2 and MPAP > 50mmHg
1989 Zeevi – LVEDV < 60-80%
1990 Karl – LVEDV < 60%, non-apex forming LV
1991 Leung-mitral valve <9mm, LV-aortic junction<5mm
1991 Parson- LV cross-sectional area <2.0cm2, LVEDV <
20ml/m2, LVEDD <13mm
LVEDV < 20ml/m2
• 43 patients undergoing valvotomy for critical AS
• Threshold Scoring:
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LV long axis ratio < 0.8
aortic root < 3.5cm/m2
mitral valve area < 4.75cm2/m2
LV mass < 35gm/m2
> 2 risk of mortality = 100%
• Discriminating equation:
14.0(BSA) + 0.943(iRoot) + 4.78(LAR) + 0.157(iMVA) – 12.03
• Score <-0.35 predicted death with 90% accuracy
following aortic valvotomy for patients with
isolated aortic stenosis
Circ 1991
Kearney DL 2013
• Neonates with
coarctation/arch
hypoplasia can
have LVEDV <
20ml/m2 and survive
with simple
coarctation repair.
 Non-apex forming
left ventricles
 Small LVEDVs
Am Heart J 1997
J Thorac Cardiovasc Surg 1999
• 20 neonates with coarctation and small LVs
 Antegrade ascending aortic flow
 Ductal dependent
• Rhodes score < -0.35 (predicting need for univentricular
repair)
• Smallest LV volume 13.8 ml/m2
• Coarctation repair via left thoracotomy
• No early or late deaths
• Hypoplasia of the left heart
• Aortic and mitral valve hypoplasia without
valvar stenosis or atresia
• Hypoplasia of the LV, LVOTO, ascending aorta
and arch with coarctation
• Antegrade blood flow in the ascending aorta
and proximal brachiocephalic vessels
• No endocardial fibroelastosis (EFE)
Ann Thorac Surg 1998
Hypoplastic left heart complex
• Initial report was 11 pts
 Weight 3.59 ± 0.49 Kg
 9 hospital survivors (82%)
 Mean duration of vent
support 12 ± 7 days
 Prolonged inotropic
support
 1 late death
 9 reoperations in 6 patients
• 4 patients underwent 6
reoperations for LVOTO
• 2 patients underwent 3
reoperations for recurrent
arch obstruction
Tchervenkov CI et al Ann Thorac Surg 1998
Hypoplastic left heart complex
• Structures increased in size
Variable
Preop
MV diameter
32.2 ± 7.0 mm/m2
-2.4
38.5 ± 7.0 mm/m2
-1.6
<0.01
LVOT diam.
17.8 ± 3.1 mm/m2
-5.6
21.9 ± 5.8 mm/m2
-3.6
<0.01
LVEDD
56.2 ± 7.7 mm/m2
-2.7
67.0 ± 18.1 mm/m2
-2.0
<0.10
LVEDV
13.6 ± 8.6 mL/m2
-5.1
19.0 ± 7.7 mL/m2
-3.6
NS
LVESV
4.2 ± 2.9 mL/m2
-3.1
8.0 ± 4.4 mL/m2
-2.0
<0.10
LV/RV ratio
0.87 ± 0.08
Tchervenkov CI et al Ann Thorac Surg 1998
Z
Before Discharge
1.09 ± 0.10
Z
p
<0.01
Hypoplastic left heart complex
• Structures increased in size
Variable
Preop
MV diameter
32.2 ± 7.0 mm/m2
-2.4
38.5 ± 7.0 mm/m2
-1.6
<0.01
LVOT diam.
17.8 ± 3.1 mm/m2
-5.6
21.9 ± 5.8 mm/m2
-3.6
<0.01
LVEDD
56.2 ± 7.7 mm/m2
-2.7
67.0 ± 18.1 mm/m2
-2.0
<0.10
LVEDV
13.6 ± 8.6 mL/m2
-5.1
19.0 ± 7.7 mL/m2
-3.6
NS
LVESV
4.2 ± 2.9 mL/m2
-3.1
8.0 ± 4.4 mL/m2
-2.0
<0.10
LV/RV ratio
0.87 ± 0.08
Tchervenkov CI et al Ann Thorac Surg 1998
Z
Before Discharge
1.09 ± 0.10
Z
p
<0.01
Hypoplastic left heart complex
• LV compliance improves
“some growth of LV structures was already
observed at the time of hospital discharge”
Tchervenkov 1998
Are these dramatic changes in size due
to growth?
• Or changes in preload and afterload?
These echos were 2 weeks apart
Are the changes due to growth?
• Or simply to changes in loading?
Grosse-Wortmann 2008
Are the changes due to growth?
• Or simply to changes in loading?
Grosse-Wortmann 2008
Are the changes due to growth?
• Or simply to changes in loading?
36 ± 9 days
36 ± 9 days
Minich 1997
Are the changes due to growth?
• Or simply to changes in loading?
24 hours
Tchervenkov 1998
Am J Cardiol 1973
1. Preload starvation is a rare cause of LV hypoplasia
Conclusion – Normal cardiac morphogenesis requires blood flow–
2. LV development is sensitive to increases in afterload but resistant to
directed remodeling in addition to intrinsic patterning.
changes in preload
LV development is afterload sensitive
LV development is not as sensitive to preload
The fetal left ventricle is preparing for big things!
• The right ventricle is the workhorse of the fetal circulation
• Fetal right heart output 1.4 X > left heart output
• But the left ventricle is preparing to take on sole ownership of the
systemic circulation
Mielke 2001
Unmasking the potential LV
At birth:
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LV output doubles
Dramatic increase in left ventricular end-diastolic dimension
Mitral valve area doubles
Are we unmasking this potential in patients in abnormal loading?
Agata Y et al J Pediatr 1991
I am making the left
ventricle grow!
So why are the criteria for an adequate
LV different for different lesions?
Neonatal LV adaptation is limited in patients with critical AS
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In-utero cavitary hypertension
Dilatation
Hypertrophy
Endomyocardial ischemia
Endocardial fibroelastosis
LV compliance impaired even before EFE develops?
Lesions with coarctation/arch hypoplasia with antegrade aortic flow
and without EFE (coarctation with nonapex forming LVs, hypoplastic
left heart complex) have preserved neonatal adaptation.
Immediate postnatal LV growth?
The dramatic acute dimensional changes following
repair of borderline LV lesions are the result of
normalization of loading conditions that permit full
expression of left ventricular phenotype
This not evidence of growth but
simple unmasking of the left
ventricle potential
Immediate remodeling can be dramatic but
continued remodeling is unpredictable
The available predictive models
• Colan et al 2006 Revised
discriminant model predicting
2V survival among neonates
with critical aortic stenosis with
intact ventricular septum and
MV Z-score > -2.
• Hickey et al 2007 Univentricular
repair survival assessment tool.
Includes patients with VSD and
arch obstruction
•
http://www.chssdc.org/content/chss-scoreneonatal-critical-aortic-stenosis
 10.98 (BSA) + 0.56 (aortic valve •
annulus z-score) + 5.89 (LAR) 0.79 (presence of grade 2 or 3
EFE) - 6.78
 New cut-off <-0.65
 90% accurate in predicting
biventricular survival in patients
with MV z-score > -2
Risk factors for poor outcome :
 1V repair: TR, ↓mitral annulus, ↓
dominant ventricular length,
large VSD
 2V repair: ↓ LVOT dimension, EFE,
LV dysfx, aortic arch hypoplasia
Small LV structures, ductal dependency with retrograde arch flow
and endocardial fibroelastosis are not a good start for a 2V repair
Is there a survival advantage to 2V repair?
• 362 neonates
with critical
LVOTO
• No survival
advantage to
2V repair
p = 0.07
…maybe a hypoplastic LV results in chronic low CO the
major determinant of outcome is the degree of LV
hypoplasia and the only difference between 1V and 2V
repair is which atrium has chronically elevated pressure?
Hickey EJ et al J Thorac Cardiovasc Surg 2007
Cardiology in the Young 2005
•Healthy
•Single Ventricle (n=55)
•TGA (n=54)
•Complex 2 Ventricle (n=73)
Parent Report - PedsQL Results, n = 182
Summary
• To make sense of all of this we need
better reporting of results
 Lesion specific
 Age specific
 Results in addition to survival and
reintervention
• Exercise tolerance
• Quality of life
• Neurodevelopmental outcome
Law of the Instrument
Law of the Instrument
"I suppose it is tempting, if the
only tool you have is a
hammer, to treat everything
as if it were a nail.”
Abraham H. Maslow (1966)
The future
• We need strategies in addition to surgery and
catheter intervention
• What we really need is a way to achieve a
hyperplastic response
 Reactivation of gene pathways, stem cell therapy, use
of paracrine effects
Hickey EJ, Caldarone CA, McCrindle BW J Am Coll Cardiol 2012
Thank you
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