Authors' objectives:

This report is intended to assess the existing evidence for the use and possible indications of implantable cardiac defibrillatorys (ICDs). It describes studies comparing ICDs with conventional treatment, mainly antiarrhythmic drugs, in patients at risk of SD due to arrhythmias.

Authors' recommendations: ICDs would be evidently effective in the following indications: Secondary Prevention Patients presenting the following when there is no treatable cause: - Heart arrest due to ventricular tachycardia (VT) or ventricular fibrillation (VF) - Spontaneous and sustained VT resulting in syncope or significant hemodynamic compromise. - Sustained VT without syncope or heart arrest associated to ejection fraction reduction (<35%) in patients whose functional class is not worse than III according to the New York Heart Association s heart failure class. Primary Prevention: - Patients with history of acute myocardial infarction (AMI) who also present all the following (non-sustained VT according to Holter + VT in the electrophysiologic testing + Poor left ventricular function with ejection fraction <35% and not belonging to a class worse than III according to the New York Heart Association s heart failure class). - Patients with history of AMI with poor ventricular function (Ejection fraction <=35%) associated with VT or VF induced during the electrophysiologic testing. AMI must have taken place more than four weeks prior to ICD implantation and the electrophysiologic testing must have been performed four weeks after AMI. - Patients with a history of AMI with poor ventricular function (Ejection fraction <=30%) associated with heart electrical conduction disorder (QRS is >120 mseg). Patients should not belong to Functional Class IV, should not present cardiogenic shock or hypotension when their baseline rhythm is stable. They should have not undergone a bypass or angioplasty in the previous three months, they should have not had an AMI during the previous month, they should not present a clinical condition or findings consistent with being candidates to coronary revascularization, they should not present irreversible brain damage due to a pre-existing brain disease nor have any other non-heart disease (e.g., cancer, kidney or liver failure) associated with an expected survival of less than one year and patients should provide their informed consent. Indications with less consensus and evidence but possibly effective. - Family history of heart disease with high risk of sudden death including: syndromes with prolonged QT, hypertrophic cardiomyopathy, Brugada s syndrome, right arrhythmogenic ventricular dysplasia and after Tetralogy of Fallot repair. There is even less consensus on this indication and less evidence, as they are uncommon syndromes. Indications where they are not recommended: - Syncope due to undetermined cause in patients without induced VT. - Continuous VT or VF. - VT or VF as a result of arrhythmias that may be treated with another surgical approach or catheter ablation (e.g., Wolf-Parkinson-White syndrome, monomorphic VT). - Ventricular tachyarrhythmias due to reversible or transient causes (AMI, metabolic disorder, trauma). - Significant psychiatric disease that may be aggravated by ICD implantation or that may prevent adequate follow-up. - End-stage disease with an expected life expectancy of less than six months. - Patients with coronary disease undergoing myocardial revascularization surgery who present poor ventricular function and prolonged QRS with no spontaneous or induced VT. - NYHA Class IV heart failure refractory to drugs in patients who are not candidates for heart transplantation. Other indications: For any other indication, there is no clear consensus in the international community as to define its use. It is worth considering that those professionals performing these practices shall meet competitiveness requirements to ensure a higher rate of success and a better follow-up. - Indications approved by MEDICARE in the USA on June 6th, 2003 based on the MADIT II findings and to be included as from 2004.

Authors' methods: Overview

Project Status: Completed

URL for project: http://www.iecs.org.ar/

Year Published: 2004

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Argentina

Organisation Name: Institute for Clinical Effectiveness and Health Policy

Contact Address: Dr. Emilio Ravignani 2024, Buenos Aires - Argentina, C1414 CABA

Contact Name: info@iecs.org.ar

Contact Email: info@iecs.org.ar

Copyright: Institute for Clinical Effectiveness and Health Policy (IECS)