Canadian implantable defibrillator study

Following resuscitation from ventricular fibrillation (VF) or pulseless VT, ICD implantation is a proven strategy for the prevention of recurrent SCD. Three prospective, randomized, controlled trials, the Antiarrhythmics Versus Implantable Defibrillators (AVID) study, the Canadian Implantable Defibrillator Study (CIDS), and the Cardiac Arrest Study Hamburg (CASH), support this strategy [27-29]. 

The Canadian Implantable Defibrillator Study studied ICD therapy versus amiodarone while CASH studied ICD therapy versus a variety of antiarrhythmic medications in patients with resuscitated SCD. Both trials found nonsignificant reductions in mortality with ICD implantation. CIDS showed a relative risk (RR) reduction of 19.7% [p = 0.14] and CASH showed a RR reduction of 23% in mortality [p = 0.08]. 

Connolly SJ, Gent M, Roberts RS, et al. Canadian implantable defibrillator study (CIDS) a randomized trial of the implantable cardioverter defibrillator against amiodarone. Circulation. Mar 21 2000 101(11) 1297-1302. 

The original intent of the ICD was to prevent recurrent cardiac arrest due to ventricular tachycardia and fibrillation. Secondary prevention of recurrent cardiac arrest was initially the prime reason for ICD implant. Five multicenter prospective randomized secondary prevention trials have been completed AVID (Antiatrhythmics Versus Implantable Defibrillator), CASH (Cardiac Arrest Study Hamburg), CIDS (Canadian Implantable Defibrillator Study), DEBUT (Defibrillator versus beta-Blockers for Unexplained death in Thailand), and MAVERIC (The Midlands Trial of Empirical Amiodarone versus Electrophysiology-guided Interventions and Implantable (Tardioverter-defibrillators) (Table 14.3) (77,118,121,149,170). 

CIDS (Canadian Implantable Defibrillator Study, 1998) ICD vs. amiodarone for VTA F Most CAD, prior MI (74%) VT with syncope VT > ISObpm with EF < 35%, or inducible VT with syncope, VF... 

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