1. Implantable Defibrillator Therapy Post Cardiac Arrest
Samir Saba, MD, FACC, FHRS
Associate Chief of Cardiology
Director, Cardiac Electrophysiology

2. Disclosures Research Support: Consulting: Boston Scientific Medtronic
St Jude Medical
Consulting:

3. Outline Guidelines Secondary Prevention Trials
AVID
CASH
CIDS
Reversible Causes of Sudden cardiac Death
AVID registry
UPMC Data
Role of the LifeVest
Indications
UPMC Experience
Advances in ICD Therapy

4. Sudden Cardiac Death in the United States

5. Implantable Cardioverter Defibrillator
Sinus Rhythm
Ventricular Tachycardia
31 J

6. ICD Guidelines after SCA
“ICD therapy is indicated in patients who are survivors of cardiac arrest due to ventricular fibrillation or hemodynamically unstable sustained VT after evaluation to define the cause of the event and to exclude any completely reversible causes” (Class I Indication; Level of Evidence: A)
ACC/AHA/HRS 2008 guidelines for Device-Based Therapy of Cardiac Rhythm Abnormalities: executive summary. J Am Coll Cardiol May 27;51(21):e1-62.

7. Cardiac Arrest Study Hamburg (CASH)
HR=0.77, P=0.08
Kuck KH et al. Circulation 2000;102:

8. Canadian Implantable Defibrillator Study (CIDS)
HR=0.80, P=0.14
Connolly SJ et al. Circularion 2000;

9. Antiarrhythmics Vs. Implantable Defibrillators (AVID) Trial
HR=0.69, P=0.02
The Antiarrhythmics versus Implantable Defibrillators (AVID) Investigators. N Engl J Med 1997;337:

10. Patient Management After Sudden Cardiac Arrest
Correct any reversible cause of SCA:
Revascularization when indicated for ACS
Correct electrolyte/metabolic abnormalities
Discontinue medications/drugs implicated in SCA
Zebras
WPW
Lightening/drowning/trauma

11. Anti-Arrhythmic Drugs After Sudden Cardiac Arrest
Use of AAD is adjunctive therapy
AAD Not needed as a matter of routine
Reserved for patients with high burden of ectopy or NSVT
May be required transiently until other triggers are reversed
The choice of AAD
Avoid class I agents (e.g. Flecainide, Propafenone) in patients with CAD or structural heart disease
Avoid class III agents (e.g. Sotalol, Dofetilide) in patients with prolonged QT interval or renal insufficiency
In the acute and subacute phases, Amiodarone is often used given that it is effective and hemodynamically tolerated
Amiodarone should be avoided when possible for long term use given its potential end-organ toxicities

12. Ventricular Arrhythmia Ablation After Aborted Sudden Cardiac Arrest
Adjunctive therapy to ICD implantation
SMASH-VT trial:
N=128 post MI and VT/VF
Randomized 1:1
ICD
ICD+RFA
HR=0.35, 95% CI 0.15 to 0.78, P = 0.007
VTACH trial:
N=110 post MI and stable VT with EF<50%
Randomized 1:1
ICD
ICD+RFA
HR=0.61, 95% CI 0.37 to 0.99, P = 0.045

13. Reversible Correctible Causes of SCA Conceptual Concerns
Determining the exact cause of a SCA and whether it is reversible is fraught with uncertainty:
Reversible causes may actually be a consequence of the SCA and resuscitation efforts rather than a cause
In addition, reversible and correctable causes may not be avoidable in future follow-up
The occurrence of SCA in the presence of a presumed reversible cause may unveil a predisposition to electrical cardiac instability

14. Reversible Correctible Causes of SCA AVID Registry
VF or Unstable VT
Reversible Cause? No
Yes
AVID Registry R
AVID Trial
No ICD
ICD

15. Reversible Correctible Causes of SCA UPMC Data
N=646 Patients
Reversible (N=435)
Irreversible (N=211)
Not Corrected (N=105)
Corrected (N=330)
ICD
(N=87)
No ICD
(N=243)
(N=31)
(N=74)
(N=41)
(N=170)
Death
N=31 (36%)
N=114 (47%)
N=107 (63%)
N=15 (37%)
N=42 (57%)
N=12 (39%)

16. Reversible Correctible Causes of SCA UPMC Data
IRREVERSIBLE
REVERSIBLE NOT CORRECTED
REVERSIBLE CORRECTED
In Acute Coronary Syndrome

17. Wearable Defibrillator (LifeVest)
Used only as a bridge to ICD
The LifeVest is indicated when there is an ICD indication but patient’s condition delays or prohibits ICD implantation
Infection
Neurological condition after SCA
Patient /family decision
Poor patient compliance

18. Advances in ICD Therapy Sub-Cutaneous ICD (S-ICD)
Advantages:
No Radiation
No endocarditis
No vascular occlusions
No need for high risk transvenous extractions
More predictable implantation times
Disadvantages:
No back-up pacing
No ATP

19. Advances in ICD Therapy MRI-Conditional ICD
Start of Scan
EKG
Pulse Ox
RF Lead Heating
Tissue Damage
Loss of Pacing Capture
Pacing Capture Threshold Change

20. Summary
Indications for ICD implantation after aborted SCA are well established for the secondary prevention of SCD
Adjunctive therapies include:
AAD
Ablation procedures
Gaps in knowledge exist regarding managing survivors of SCA in the context of a reversible cause
Recent advances in ICD technology:
MRI-compatible ICD
Subcutaneous ICD
Home monitoring
The LifeVest is only used as a bridge to ICD when ICD therapy has to be delayed in a SCA survivor

21. Questions?