Authors' objectives:

This review aims to assess the available evidence on implantable cardioverter-defibrillators for the primary prevention of sudden cardiac death due to ventricular arrhythmias.

Authors' recommendations: With regard to ICDs for the primary prevention of sudden cardiac death due to ventricular arrhythmias, the ICSI Technology Assessment Committee concludes: The implantation of a cardioverter-defibrillator is a relatively safe procedure, with a perioperative mortality rate of 0% to 1.0% in most studies, which may be related more to underlying disease than the procedure itself. Significant morbidity may occur in 1% to 3% of patients and includes pneumothorax, system infection, and lead dislodgement. Although the ideal candidate for an ICD has not yet been defined, evidence from randomized controlled trials (RCTs) (e.g., SCD-HeFT) shows that ICDs are most efficacious in decreasing SCD and all-cause mortality in patients with NYHA class II or III CHF from ischemic or non-ischemic causes, a left ventricular ejection fraction (LVEF) of 0.35 or less, no coronary revascularization procedure within three months prior to ICD implantation, and no myocardial infarction (MI) within one month prior to implantation In addition, for patients with NYHA class I CHF, evidence from a large randomized controlled trial (MADIT II) has shown that ICDs are efficacious in decreasing SCD and all-cause mortality only for patients with ischemic heart disease. Additional patient selection criteria for this subgroup include a history of MI (over one month prior to ICD implantation), an LVEF of 0.30 or less, and no coronary revascularization procedure within three months prior to implantation. There is not enough evidence to show that ICDs are efficacious for the primary prevention of SCD in other cardiac disorders, such as Brugada syndrome and hypertrophic cardiomyopathy. Evidence from a large randomized controlled trial (COMPANION trial) supports the efficacy of biventricular ICD use in conjunction with cardiac resynchronization therapy (CRT) for the prevention of all-cause mortality, decreased hospitalizations, and improvements in quality of life for patients with NYHA class III/IV congestive heart failure, an LVEF of 0.35 or less, and a QRS width of at least 120 milliseconds in patients with ischemic or non-ischemic cardiomyopathy. Although optimal medical therapy should be aggressively pursued, there is not enough evidence to determine the amount of time needed for medical therapy prior to measuring ejection fraction for determining the appropriateness of ICD implantation (i.e., to determine maximal LVEF).

Authors' methods: Review

Project Status: Completed

URL for project: http://www.icsi.org/knowledge/detail.asp?catID=107&itemID=2149

Year Published: 2005

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Institute for Clinical Systems Improvement

Contact Address: 8009 34th Avenue South, Suite 1200, Bloomington, MN, USA. Tel: +1 952 814 7060; Fax: +1 952 858 9675

Contact Name: icsi.info@icsi.org

Contact Email: icsi.info@icsi.org

Copyright: Institute for Clinical Systems Improvement (ICSI)