This document discusses risk stratification and management of ventricular arrhythmias in adults with congenital heart disease, particularly those with tetralogy of Fallot (ToF). It finds that ventricular tachycardia (VT) ablation is effective for treating VTs in ToF patients, with most VTs being fast and monomorphic. Risk factors for sudden cardiac death in ToF include prolonged QRS duration, ventricular dysfunction, nonsustained VT on Holter monitoring, and syncope. Cardiac MRI can identify predictors of death and sustained VT like right ventricular hypertrophy and fibrosis. Electrophysiological study can assess risk and guide decisions about implantable cardioverter defibrillator placement.

1. V I I C O R S O S U L L E C A R D I O P A T I E C O N G E N I T E D E L L ’ A D U L T O
Napoli, 22·09·2016
Pasquale Vergara, MD, Ph-D
Arrhythmology Unit - San Raffaele Hospital - Milano - Italy
ARITMIE VENTRICOLARI NEI CONGENITI ADULTI:
INDICAZIONI E TIMING DELL’ABLAZIONE
GESTIONE DEL PAZIENTE ADULTO CON ARITMIE

2. DEATH IN ADULTS CONGENITAL HEART DISEASE PATIENTS
Oechslin EN, Am J Cardiol 2000;86:1111-1116
2,609 adults @ Toronto Hospital, between 1981 and 1996
Peri-op:
18%
other
cardiovasc:
18%
CHF: 21%
Sudden
Death:
26%
Mechanism of death

3. 61
39
0 20 40 60 80
VT
cardiac arrest
⇝ 2162 adult CHD pts underwent ICD implantation in 24 studies
SD PREVENTION BY ICD IN CHD PATIENTS
Vehmeijer JT EHJ 2016;37:1439-1448
53%
47%
primary prevention secondary prevention
Type of congenital heart
disease in ICD recipients
Indications to implant

4. VENTRICULAR ARRHYTHMIAS IN CHD PATIENTS WITH ICD
Appropriate ICD interventions in CHD
⇝ 24,4% pts received ≥1 interventions on VT/VF
⇝ a remarkably high rate of appropriate ICD interventions,
both in primary prevention (22% in 3.3 years) and in
secondary prevention (35% in 4.3 years)
Vehmeijer JT EHJ 2016;37:1439-1448
selection bias
selection bias

5. •
•
•
•
NEJM 2008
804 pts from the ICD branch of the SCD-HeFT trial.
ICD programming: 1 zone of therapy; 18/24 beats; rate ≥188 bpm
•

6. R. Tung
M. Vaseghi
D. S.Frankel
P. Vergara
L. Di Biase
K.Nagashima
R. Yu,MD
S. Vangala
C. Tseng
E. Choi
S. Khurshid
M. Patel
N. Mathuria
S. Nakahara
W. S.Tzou
W.H.Sauer
K. Vakil
U. Tedrow
J.D. Burkhardt
VN.Tholakanahall
A. Saliaris
T. Dickfeld
J. P. Weiss
T. J. Bunch
M. Reddy
A. Kanmanthareddy
D. J.Callans
D.Lakkireddy
A. Natale
F.Marchlinski
W.G.Stevenson
P. DellaBella
K. Shivkumar
2061 pts with
structural heart
disease referred
for CA of scar-
related VT from
12 international
centers

7. VT ABLATION IN EUROPE
Median number of AF ablation = 50
Number of VT ablations in Germany in 2015: 416 ablations per million inhabitants

8. 128 pts with
previouos Myocardial infarction &
severe LV dysfunction
Enrollement criteria:
1) Indication to ICD implantation related to:
-Spontaneous VF or unstable VT
-Syncope and VT induction at EPS
- Mean LVEF: 0.25
2) ICD implantation for primary prophylaxis
and appropriate ICD therapy for a single
event during follow-up
No AAds (except betablockers)
NEJM 2007
Randomized to:
- ICD
vs
- RF ablation + ICD
SMASH-VT

9. NEJM 2007
Catheter ablation is an effective treatment to reduce ICD shocks, but
survival benefit not demonstrated
65% risk reduction of receiving ICD therapy in the
following 2 years
Overall reduction of ICD therapies burden in the ablation
group compared to the control group
No evidence
of survival
benefit

10. CURRENT PRACTICE FOR TIMING OF VT ABLATION
Proclemer Europace 2012;14:135-137

11. BETTER OUTCOME WHEN ABLATION IS PERFORMED EARLIER
• early (<30 days after the first documented VT)
• delayed (between 1 month and 1 year)
• very late (>1 year)
ICD implant 1st ATP 1st shock 1st ES
Clinical VT
Myocardial infarction
No survival benefit
In SMASH-VT trial
Late (≥2 VTs with the 1st and most recent VT
separated by at least 1month
2: Early (all others)
Frankel D; JCE 2011;22:1123-1128
Dinov; Circ A E 2014;7:1144-1151

12. (Days)
p < 0,001
Number No ES 1262 1044 985 963
at risk ES 677 517 471 421
VT ABLATION AFTER PAROXYSMAL EVENTS OR STORM?
Vergara et al in submission
International VT Ablation Center Collaborative Group
677 pts with ES vs 1262 without ES
2061 pts with
structural heart
disease
referred for CA
of scar-related
VT from 12
international
centers

13. (Days)
Number No inducible VTs 394 331 311 281
at risk Non-clinical VT inducible 139 101 86 73
Clinical VT inducible 42 23 18 15
Not tested 39 24 21 20
PES RESULT AFTER ABLATION PREDICTS SURVIVAL
Vergara et al in submission
International VT Ablation Center Collaborative Group
Survival free from death in patients with ES by the results of acute PES after the ablation.

14. CONGENITAL HEART DISEASE PATIENTS & VTs

15. SUDDEN CARDIAC DEATH AND VENTRICULAR ARRHYTHMIAS IN
PATIENTS WITH CONGENITAL HEART DISEASE
Priori S Eur Heart J. 2015;36:2793-867
2015 ESC Guidelines
ICD Catheter ablation Programmed ventricular stimulation

16. SUDDEN CARDIAC DEATH AND VENTRICULAR ARRHYTHMIAS IN
PATIENTS WITH CONGENITAL HEART DISEASE
Priori S Eur Heart J. 2015;36:2793-867
2015 ESC Guidelines
Catheter ablation
Programmed ventricular
stimulation
ToF with ≥1 Risk Factor
CHD + NSVT
Symptomatic sustained VT & ICD Alternative to drugs
Recurrent VTs
Alternative to ICD
Additional to ICD
Sustained VTs and
identified critical isthmus
Undergoing cardiac
surgery

17. SUDDEN CARDIAC DEATH AND VENTRICULAR ARRHYTHMIAS IN
PATIENTS WITH CONGENITAL HEART DISEASE
Priori S Eur Heart J. 2015;36:2793-867
2015 ESC Guidelines
Catheter ablation
Programmed ventricular
stimulation
ToF with ≥1 Risk Factor
CHD + NSVT
Symptomatic sustained VT & ICD Alternative to drugs
Recurrent VTs
Alternative to ICD
Additional to ICD
Sustained VTs and
identified critical isthmus
Undergoing cardiac
surgery

18. ⇝ During 30.4±29.3 months of follow-up, 91% of patients remained free of VT
The reentry circuit isthmuses of all induced 15 VTs (mean CL 276±78 ms; 73% poorly tolerated), identified
by activation, entrainment, and/or pace mapping, were located in an anatomic isthmus
VT ABLATION IN ToF IS FEASIBLE AND EFFECTIVE
Zeppenfeld Circ 2007;116:2241-52
⇝ 11 patients in 2 referral centers

19. VT IN ToF PATIENTS
Kapel GF, CircAE 2014;7:889-897

20. PATIENTS WITH VTS AFTER REPAIR OF CHD

21. SUDDEN CARDIAC DEATH AND VENTRICULAR ARRHYTHMIAS IN
PATIENTS WITH CONGENITAL HEART DISEASE
Priori S Eur Heart J. 2015;36:2793-867
2015 ESC Guidelines
Catheter ablation
Programmed ventricular
stimulation
ToF with ≥1 Risk Factor
CHD + NSVT
Symptomatic sustained VT & ICD Alternative to drugs
Recurrent VTs
Alternative to ICD
Additional to ICD
Sustained VTs and
identified critical isthmus
Undergoing cardiac
surgery

22. TO IMPLANT ICDS OR NOT TO IMPLANT?
ICD should always
be implanted in
CHD patients
undergoing VT
ablation
Ablation is
enough for
treating VTs
⇝ICDs prevent SD !!!! ⇝Ablation also might improve survival
⇝Lead malfunction & infection are still a
problem in young patients
⇝I don’t know who are patient who
might really need ICD after ablation, so
I’ll study the issue
⇝ICD are very small & reliable
⇝I don’t know who might really need
ICD after ablation, so I’ll implant all
VT patients

23. • LVEF > 30%
• well-tolerated SMVT (no syncope)
VT ABLATION IN PATIENTS WITHOUT ICD
Maury P. European Heart Journal 2014;35, 1479–1485
⇝ 166 patients
All-cause mortality rate in the control group of
implanted patients presenting with SMVT and
sharing similar clinical characteristics was similar (12%).

24. WHAT TYPE OF VT DO ToF EXPERIENCE?
Tetralogy of Fallot is the largest subgroup of ICD recipients with CHD
Sudden cardiac death is the most frequent mode of demise in infant
survivors
Prevalence of clinical sustained VT : 11.9%
Low overall annual incidence of SCD (0.15%)
Prevalence of SCD in ToF varies between 2.0 and 8.3%
• EPS was performed in 80% of pts
• sustained VAs were inducible in 58%:
• Monomorphic VTs in 16 pts (76%),
• polymorphic VTs in 3 (14%),
• VF in 2 (9%)
• Combined monomorphic VT and VF in 1 pt (5%).
Koyak Z, Int J Cardiol 2013;167:1532-1535

25. VT IN TOF PATIENTS
⇝ The majority of arrhythmias in adult rTOF are fast
monomorphic VTs
⇝ These arrhythmias are likely to be fatal if untreated,
even in patients with good biventricular function
⇝ 2/3 of rTOF patients that die suddenly, typically early
to middle-aged adults, have preserved cardiac
function and good functional status prior to the
event,  non-heart failure related arrhythmia
mechanisms
Kapel GF, European heart journal 2016

26. RISK STRATIFICATION

27. MRI PREDICTORS OF DEATH AND SUSTAINED VT IN ToF
Valente AM, Heart. 2014;100:247-253
3 categories of risk factors:
• Patient history
• electrophysiologic markers
• hemodynamic abnormalities
⇝ 873 repaired Tetralogy of Fallot patients
• Cardiac MRI
• 12-lead ECG within 1 year
from MRI
• clinical follow-up ≥1 year or
occurrence of a primary
outcome
⇝ Primary outcome:
death or sustained VT

28. MRI PREDICTORS OF DEATH AND SUSTAINED VT IN ToF
Valente AM, Heart 2014;100:247-253
RV hypertrophy
 myocyte volume
 collagen & gross fibrosis
VT re-entry
substrate


29. MODELS TO PREDICT SUDDEN DEATH IN ToF
⇝ LV global longitudinal strain, MAPSE, right atrial area and RV fractional area
change provided the best combination of simplicity and prognostic value (c
statistic of 0.70 for both)
Diller Circulation 2012;125:2440-2446
LV GLOBAL LONGITUDINAL STRAIN
Freedom from sudden cardiac death (SCD) or life-threatening arrhythmia (LTA)
Cut-offs:
• MAPSE <12 mm
• right atrial area >20 cm2
• RV fractional area change <32%
• LV-LS <15%
⇝ 413 repaired Tetralogy of Fallot patients

30. ⇝ Those with progressive increase of QRS duration or impairment of ventricular function are
at risk of sudden cardiac death
⇝ Keep monitoring patients!
QRS duration
PREDICTORS OF SUDDEN CARDIAC DEATH IN A-CHD
Koyak Z. Europace 2016
Patients who died suddenly
due to an arrhythmia
Matched controls Controls
Cases

31. SUDDEN CARDIAC DEATH AND VENTRICULAR ARRHYTHMIAS IN
PATIENTS WITH CONGENITAL HEART DISEASE
Priori S Eur Heart J. 2015;36:2793-867
2015 ESC Guidelines
Catheter ablation
Programmed ventricular
stimulation
ToF with ≥1 Risk Factor
CHD + NSVT
Symptomatic sustained VT & ICD Alternative to drugs
Recurrent VTs
Alternative to ICD
Additional to ICD
Sustained VTs and
identified critical isthmus
Undergoing cardiac
surgery

32. ELECTROPHYSIOLOGICAL STRATIFICATION OF ToF PATIENTS
Kapel GF, European Heart Journal 2016
18 pts received an ICD before discharge:
• 6 pts: failed VT ablation
• 2 pts: VT ablation not performed
• 2 pts: VT ablation successful, but depressed cardiac function
• 4 pts: VT ablation successful, but patients preference
• 4 pts: depressed cardiac function
Patients were considered at risk when at least 1
prior reported risk factor was present:
• Syncope
• QRS duration ≥180 ms
• non-sustained VT on Holter
• ≥ moderate dysfunction of LV or RV
• late repair (≥5years of age)
• and the presence of a transannular patch
Electoanatomical mapping for the
evaluation of the anatomical and
electrically conducting isthmses

33. ABLATION OF VT ISTHMUS IN ToF
Kapel GF, European heart journal 2016

34. ⇝All 63 patients without a slow conducting isthmus at discharge remained free
from VT (group A)
ELECTROPHYSIOLOGICAL STRATIFICATION OF ToF PATIENTS
Kapel GF, European Heart Journal 2016

35. ⇝ Slow conducting anatomicaI isthmuses (<0.5 m/s) were the
substrate for all documented and induced VT in rTOF with
preserved cardiac function.
⇝ This substrate could not be predicted by previously suggested
clinical risk factors.
⇝ Repaired TOF patients without an arrhythmogenic isthmus at
baseline or after successful isthmus ablation, in the presence of
a preserved biventricular function, may not require ICD
implantation.
ELECTROPHYSIOLOGICAL STRATIFICATION OF ToF PATIENTS
Kapel GF, European Heart Journal 2016

36. ⇝ In 11 of 28 (39%) patients with rTOF, right-sided RFCA failed to abolish all
inducible VTs
⇝ preoperative electrophysiology study and intraoperative ablation of
anatomic isthmuses related to VT is a reasonable consideration even in
the absence of spontaneous VTs
VT ABLATION APPROACH:
RIGHT VENTRICLE IS NOT ALWAYS THE RIGHT TARGET IN ToF
Kapel GF, CircAE 2014;7:889-897

37. ⇝The anatomic isthmus between the PV and the VSD may no longer be
approachable for RFCA from RV endocardium and may, therefore, require a left-
sided approach.
⇝The combination of graft material and hypertrophy may prevent effective RFCA
after PV replacement even if a combined (RV/LV) approach is used
SURGERY & VT ISTHMUS
Kapel GF, CircAE 2014;7:889-897

38. CASE # 1 - 22 yo MALE ToF
• 1991 (1 yo) surgical correction with
VSD patch + trans-annular patch
• 1992 redo for VSD patch detatchment
• 2005 VT -> flecainide
• 2006 VT ablation
• 2007 redo VT ablation + ICD implant
• 2009 RV lead malfunction -> lead
extraction
• Several VTs

39. CARDIACT CT
• RV dilatation with EF 48%
• VSD patch + infundibular patch

40. BIPOLAR VOLTAGE MAP
Electrically silent area:
Infundibular patch

41. RADIOFREQUENCY VT ABLATION

42. CONCLUSIONS
⇝ In TOF patients the VT substrate is related to
macroreentry involving an anatomical isthmus
⇝ Ablation is recommended in CHD patients with recurrent
VT
⇝ VT ablation before ICD implantation should be indicated
only in highly selected cases
⇝ Electro-anatomical mapping might be used for the
stratification of patients at risk for VTs
⇝ Possible concomitant treatment