1. Paul Dorian, MD Hôpital St Michel, Toronto
Défibrillateurs Implantables pour Prévenir la Mort Subite- Pour Qui et Comment?
Paul Dorian, MD
Hôpital St Michel, Toronto

2. Patient ER (FV spontanée)

3. The Inventor of the AICD
History of the AICD
1966- Dr. M. Mirowski
conceives the idea of an implantable defibrillator after his friend, colleague and mentor Dr. Harry Heller dies of sudden cardiac death
Guidant logo in upper right corner/
Dr. Michel Mirowski
( )
The Inventor of the AICD

4. History of ICD Therapy
The first device is implanted and tested in an animal
The first patient is implanted with an AICD device

5. ICD’s Today ( 2004) Small devices – Pectoral site
Transvenous, single incision
Local anesthesia; conscious sedation
hospital stay usually 0-1 days
Few complications ( similar to pacemakers_)
Perioperative mortality < 0.5%
Programmable therapy options
Single- or dual-chamber therapy
Battery longevity up to 9 years
Recognizes VT and VF – 99%
Terminates VT and VF – 99%
Pacemaker
Today’s devices are implanted pectorally, either subcutaneously or submuscularly in most patients.
1998 actual implants (estimates): 45,000 in U.S. 10,000 outside of U.S. 55,000 Worldwide
Battery longevity projections for Medtronic devices:
GEM years – 100% pacing, monthly shocks
6.9 years – 100% pacing, quarterly shocks
9.1 years – 100% sensing, 0% pacing, quarterly shocks
GEM DR years – 100% pacing, monthly shocks
6.6 years – 100% pacing, quarterly shocks
7.8 years – 0% pacing, monthly shocks
9.6 years – 0% pacing, quarterly shocks
Micro Jewel II years – 100% pacing, monthly shocks
7.8 years – 100% sensing, 0% pacing, quarterly shocks
Jewel AF years – 100% pacing, monthly shocks
8.9 years – 0% pacing, quarterly shocks

6. Anti-tachycardia pacing therapy
Antitachycardia Pacing (ATP)
Shock (cardioversion)

7. Qui a besoin d’un Defibrillateur Implantable ?
Tous qui sont a haut risque de TV soutenue ou FV:
Dysfonction du VG
Maladie Coronarienne ou cardiomyopathie
Surtout histoire antecedante de tachycadie ventriculaire ou arret cardiaque ( FV)

8. The Penalty for Failure is Death Fu Manchu

9. Relation between triggers and substrate in SCD
Big Trigger Trigger Small trigger
lightning
NSVT
VPB, EAD
Ischemia
Tachycardia
Adrenergic drive
Good EF Substrate Poor EF
The substrate is DYNAMIC

10. Categories of ICD indications
“Secondary prophylaxis” :
Patients with a prior history of sustained VT or VF
No reversible factors ( eg acute MI)
“Primary prophylaxis” :
Patients with no history of sustained VT or VF
Risk factors for sudden death - severe LV dysfunction
- Heart failure symptoms
- Non sustained VT ?
- inducible VT at EP study?

11. Meta-Analysis of ICD Secondary Prevention Trials: AVID, CASH, CIDS
Pts with prior sustained VT or VF
Death
Arrhythmic Death
Amio
Amio
ICD
ICD
Years
Years
Number at risk:
ICD:
Amio:
Connolly et al. Eur Heart J 2000;21:2071-8

12. Long term follow up of Patients Treated with Amiodarone in CIDS
(SMH, n=60)
Mortality
100
Mortality or Recurrence of Arrhythmia 80
Mortality, Recurrence of Arrhythmia or Discontinuation of Amiodarone Due to Side Effects
Freedom From Event
(%) 60 40 20 2 4 6 8 10 12
Time (Years)
Bokhari et al Circ. 2004

13. Vaccin pour prevenir la Mort Subite?
Facteurs de risque –
Fraction d’éjection < 30%
Cicatrise du VG surtout ancien infarctus
Tachycardie non soutenue sur Holter ( ?)
symptômes d’insuffisance cardiaque

14. Time after Enrollment (Years)
MUSTT Study: CAD, EF < 40% , NSVT ( > 4d post MI), inducible VT/VF
(17% < 1mo, 22% 1mo-1 yr post MI)
0.6
No EP-Guided AA Rx
EP-Guided Rx, No ICD
0.5
Not randomized
EP-Guided Rx, ICD
0.4
Mortality Rate
0.3
p < 0.001
0.2
0.1 1 2 3 4 5
Time after Enrollment (Years)
Buxton AE. N Engl J Med. 1999;341: 20

15. Probability of Survival
MADIT-II : ICD’s for patients with prior MI and EF < 30%, no prior arrhythmias
1.0
0.9
Defibrillator
0.8
Probability of Survival
0.7
Conventional
P = 0.007
0.6
0.0 1 2 3 4
Year
No. at Risk
Defibrillator (0.91) (0.94) (0.78)
Conventional (0.90) (0.78) (0.69)
Moss AJ. NEJM 2002;346:

17. QRS Prolongation: A Strong Independent Risk Factor for Mortality in Patients with Severe Ischemic Heart disease
QRS Duration, ms
Mortality, %
<100 (n=58)
13.8
(n=86)
17.6
(n=65)
23.6
(n=44)
45.5
 140 (n=60)
43.3
Kalahasti V et al, PACE 2002;24:528

18. Noninvasive ECG Parameters in Multivariate Cox Model for Predicting Total Mortality in MADITT II Patients Randomized to Conventional Therapy
Variable
Age ≥ 65 years
NYHA ≥ II
BUN > 25
No BB use
AFib
QRS > 0.12 sec HR
1.47
2.00
1.94
1.57
2.36
1.90
(95% CI)
( )
( )
( )
( )
( )
( )
P value
0.164
0.008
0.010
0.089
0.021
0.013
Zareba et al, NASPE 2002

19. HR = 0.37 (p=0.004) 63% reduction in mortality
Survival in Defibrillator Group and Conventional Treatment Group in 364 MADITT II Patients with QRS > 0.12 sec (excluding paced patients)
MORTALITY
2-yr
36%
14%
3-yr
53%
21%
Conv
ICD
HR = 0.37 (p=0.004) % reduction in mortality
Zareba et al NASPE 2002

20. SCD HeFT-Enrollment Scheme
DCM ± CAD and CHF
EF ≤ 35%
NYHA Class II or III
6 minute walk, Holter R
Placebo
Amiodarone
ICD
n=847
n=845
n=829

21. Mortality by Intention to Treat
28.9%
35.8%
34.1%
Amiodarone vs. Placebo
ICD Therapy vs. Placebo HR
1.06
0.77
97.5% CI
0.86, 1.30
0.62, 0.96
P-Value
0.529
0.007
ICD pts – 5%/yr risk of appropriate shock

23. No Technology is perfect
Inappropriate shocks
Lead fracture. Dislodgement
Infection
Short battery life ( 5-7 years)
Complex programming and follow-up
Doesn’t prevent all sudden death

24. ICDs in SCD-HeFT 2.2% not implanted 4.0% removed, not replaced
4.6% serious complications at implant, no deaths
9.4% serious complications in follow-up
5.0% appropriate shocks / pt / yr
total: 7.4% shocks / pt / yr

25. Aucune technologie n’est parfaite
choc non appropriée ( pour tachycardie non dangereuse)
Infection
Durée courte de vie des batteries ( env. 5 ans)
programmation compliquée
Et…. Prolonge pas la vie de tous

26. CABG Patch : ICD immediately after CABG EF <35%, +ve SAECG30
27%
24% 20
Cumulative Mortality (%)
Defibrillator Group 10
Control Group
p = 0.64 12 24 36 48
Month
Defibrillator Gr
Control Group
Bigger JT. NEJM 1997;337(22):

27. Early post MI ICD vs control: All-Cause Mortality
DINA IT
Early post MI ICD vs control: All-Cause Mortality
Months
Day 6-40 post MI, EF < 35%, depressed HRV

28. Why Don’t ICDs Save Everyone From Dying a Sudden Death?
Some patients die from CHF or MI or Asystole / PEA 
Some VT / VF is a precursor to non-arrhythmic death 
Some VT / VF presents as electrical storm - electrical success, but poor outcome

29. ICD Implant Rates continue to diverge between Europe and USA
MUSTT
MADIT II
???
Annual
ICD implants
per million
inhabitants
MADIT & AVID
USA *
ICD implant rates/million population for all of Europe (red), compared to the U.S. (yellow), during the 1990s. Superimposed are the important studies – MADIT, AVID, and MUSTT (see later slides for details) – the first two published in 1996, and MUSTT in 1999, all of which had an important impact on ICD therapy acceptance in the U.S., but apparently little or no impact in Europe.
Although the European implant rates are also steadily increasing, It is apparent that the curves are in fact diverging, with the U.S. over 200 implants/million, roughly 5-fold the European rate.
The next major study, MADIT II, finished end 2001, and we will be interested to see the impact both in Europe and the U.S. of MADIT II.
CANADA
Europe
Updated from Nisam S, 2000

30. The Real Questions in Deciding on ICD Recommendation
What is the annual risk of sudden arrhythmic death?
(or the risk / device lifetime, ~ 5 years)
What is the annual risk of death from other causes?
All ICDs are Prophylactic

31. MERCI

32. Meta-analysis of All Primary Trials of ICD for Primary Prophylaxis

33. Recommendations for ICD
Class I:
Patients with ischemic heart disease and LV ejection fraction ≤ 30%, measured at least one month post myocardial infarction and three months post coronary revascularization procedure*. (Level of Evidence: A)
Add risk stratification during the presentation
* Coronary bypass surgery or percutaneous coronary intervention

34. ACC/AHA format of classification of recommendations
Class IIa
Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment.
IIa: Weight of evidence/opinion is in favour of usefulness/efficacy.
IIb: Usefulness/efficacy is less well established by evidence/opinion.

35. Recommendations for ICD
Class IIa:
Patients with ischemic heart disease and LV dysfunction (LVEF = %), measured at least one month post myocardial infarction (MI) and three months post coronary revascularization procedure* with inducible VF/sustained VT at electrophysiology study. (Level of Evidence: B)

36. Recommendations for ICD
Class IIa:
Patients with non-ischemic cardiomyopathy present for greater than or equal to 9 months, LV dysfunction (LVEF ≤ 30 %), and heart failure NYHA functional class II-III. (Level of Evidence: B)
Patients with familial or inherited conditions such as but not limited to long QT syndrome, hypertrophic cardiomyopathy, Brugada syndrome or arrhythmogenic right ventricular cardiomyopathy, and at a high risk for life-threatening ventricular tachyarrhythmias. (Level of Evidence: B)

37. Recommendations for ICD
Class IIb:
Patients with ischemic heart disease, prior myocardial infarction (MI), LV dysfunction (LVEF = 31-35%) with either no inducible VF/sustained VT at electrophysiology study, or without an electrophysiology study. (Level of Evidence: C)
Patients with non-ischemic cardiomyopathy present for at least nine months, LV dysfunction (LVEF = 31–35%) and NYHA functional class II-III heart failure. (Level of Evidence: C)
Severe symptoms (e.g. syncope) attributable to sustained ventricular tachyarrythmias while awaiting cardiac transplantation. (Level of Evidence: C)