Implantable Cardioverter Defibrillator - the evidence behind the guidelines
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Transcript of Implantable Cardioverter Defibrillator - the evidence behind the guidelines
EBM Presentation: Implantable Cardioverter Defibrillators
5 June 2015Koh Choong Hou
Supervisor: Tan Vern Hsen
Scope• History of ICDs
• Indications for ICDs
• Major Trials
Pioneers of ICDs - “M&M”
Martin Mower
Michel Mirowski
*Dr Chow Wei En©
*
Indications for ICDs (ACC)
Wait… How about medical therapy
first?
SCD Prevention Trials - Antiarrhythmic Agents
• CAST I [Cardiac Arrhythmia Suppression Trial (1991)]
• ESVEM [Electrophysiologic Study vs ECG Monitoring (1993)]
• GESICA [Grupo de Estudio de la Sobrevida en la Insuficiencia Cardiaca en Argentina (1994)]
• CHF STAT [Congestive Heart Failure: Survival Trial of Antiarrhythmic Therapy (1995)]
• SWORD [Survival with Oral d-Sotalol (1996)]
• CAMIAT [Canadian Amiodarone Myocardial Infarction Arrhythmia Trial (1997)]
• EMIAT (European Myocardial Infarction Amiodarone Trial (1997)]
CHF STAT
SWORD Trial
EMIAT (European MI Amiodarone Trial)
SCD Prevention Trials - ICDs• Secondary Prevention
• CASH [Cardiac Arrest Study Hamburg (1994)]
• AVID [Amiodarone vs Implantable Defibrillator (1995)]
• CIDS [Canadian Implantable Defibrillator Study (2000)]
• Primary Prevention
• MADIT [Multicentre Automatic Defibrillator Implantation Trial (1996)]
• CABG-PATCH (1997)
• MUSTT [Multicentre Unsustained Tachycardia Trial (1999)]
• MADIT II (2002)
• DEFINITE (2004)
• DINAMIT (2004)
• SCD-HeFT (2005)
ICDs in Secondary Prevention
Key Trials: ICD in Secondary Prevention
• Antiarrhythmics vs ICDs
• First trial of such nature to be completed
• Demonstrated superiority of ICDs over AADs (primarily amiodarone)
AVID Trial
A Comparison of Antiarrhythmic-Drug Therapy with Implantable Defibrillators in Patients Resuscitated from Near-Fatal Ventricular ArrhythmiasThe Antiarrhythmics versus Implantable Defibrillators (AVID) Investigators. N Engl J Med 1997; 337:1576-1584
AVID Trial
CIDS (Canadian Implantable Defibrillator Study)
CIDS (Canadian Implantable Defibrillator Study)
ICD Better Amiodarone Better
CASH (Cardiac Arrest Study Hamburg)
Sub-optimally Addressed Issues
• Beta-blockade - have we really optimised medical therapy prior to device implantation?
• Is 35% the magic EF?
• Under-represented population - the impact of ICD in non-ischaemic CMP?
Are AADs more protective over the long term horizon?
Meta-analyses of the ICD Secondary Prevention Trials. Connolly et al. European Heart Journal 2000 (21) 2071-2078
HRS/ACC/AHA Expert COnsensus Statement on the Use of ICD Therapy in Patients who are not included or not well represented in Clinical Trials. Heart Rhythm 2014; 11:1270-1303
HRS/ACC/AHA Expert COnsensus Statement on the Use of ICD Therapy in Patients who are not included or not well represented in Clinical Trials. Heart Rhythm 2014; 11:1270-1303
ICD within 40 days of AMI
ICDs in Primary Prevention
Class I Indication? Not always clear cut…
Accurate & Reproducible Measurement of LV Volume & EF by Contrast Echocardiography. S Malm et al. JACC 2004:1030-5
Comparison of LVEF & Volumes in Heart Failure by Echo, Radionuclide Ventriculography & CMR. Are they interchangeable? Bellenger et al. Eur Heart J (2000) 21:1387-96
MADIT II
MADIT I & II
MUSTT
DEFINITE
ICDs prevent
arrhythmic deaths but will kill you
in other ways???
Shock
SCD-HeFT
Matching the Evidence to the
Guidelines
Indications for ICDs (ACC)SCD HeFT
Indications for ICDs (ACC)DEFINITE
Indications for ICDs (ACC)
MADIT II
Indications for ICDs (ACC)MUSTT
MADIT I
Indications for ICDs (ACC)
AVID, CIDS, CASH
Wever EF, Hauer RN, van Capelle FL, et al. Randomized study of implantable defibrillator as first-choice therapy versus conventional strategy in postinfarct sudden death survivors. Circulation. 1995;91: 2195–203.
• The Grey Zone: 35% < EF < 40%. EPS is “useful”.
• NSVT post MI, EF > 35%
• NSVT post MI, EF > 35% with negative EPS
• NSVT in NICMP
• Elderly - what is the “age cut-off”?
• Beyond EF
• Dual vs Single Chamber; Programming (minimising inappropriate shocks)
Unaddressed Scenarios