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