Authors' objectives:

The aim of this report was to assess the evidence available on the usefulness of implantable cardioverter defibrillators (ICD) to prevent sudden death in high risk patients.

Authors' results and conclusions: I. Secondary prevention Based on the results of 5 randomized controlled clinical trials and two meta-analyses included in the revision, according to the CASH, AVID, CIDS and VETERANS studies, the patients that would clearly benefit from the use of ICD and achieve a 12.3% to 8.8% decrease of annual mortality are those who: - survived a cardiac arrest due to VF (ventricular fibrillation) or VT (ventricular tachycardia), - had spontaneous and sustained VT resulting in syncope or significant hemodynamic involvement, or - had symptomatic VT without syncope or cardiac arrest, and, at the same time, have poor ventricular function (ejection fraction <35%), are not class IV according to the functional classification's heart failure for the New York Heart Association. On the other hand, there is not a clear benefit for those patients with good ventricular function. Nor it is necessary to indicate ICD based on electrophysiological studies (MAVERIC study). II. Primary prevention In summary, the information presented in 9 randomized controlled clinical trials, benefits were shown in: - patients with history of acute myocardial infarction (AMI) at least four weeks before, with left ventricular ejection fraction (LVEF) 35% , non-sustained ventricular tachycardia (NSVT) on Holter and induced VT in the electrophysiologic study (MADIT I and MUSTT: HR 0.46; CI 95% 0.26 to 0.82), and - patients with history of acute myocardial infarction (AMI) at least four weeks before, with a LVEF of 30% (MADIT II: HR 0.69; CI 95% 0.51 to 0.93). No benefits were observed: - in patients with early AMI (DINAMIT) - in routine use together with elective by-pass surgery (CABG). There might be some benefit, although results in comparison with pharmacologic treatment are not conclusive, for patients: - with functional class II or III for New York Heart Association's heart failure with ischemic or idiopathic dilated cardiomyopathy and a LVEF 35% (CAT, AMIOVIRT, DEFINITE, SCD-HeFT).

Authors' recommendations: ICD is effective in reducing the risk for sudden death in different populations, although it is an invasive procedure which is not free from risks and adverse events and with high costs. The placement of this device to all the groups in which some degree of benefit has been demonstrated implies an intervention to a vast population. It is essential to identify the subgroups in which this practice is most effective, especially if we take into account that not all the groups of patients would benefit equally. The absolute benefit of ICD placement is higher in patients under secondary prevention and in some groups chosen already under primary prevention. However, for many indications, it is not clear which sub-groups would benefit most. The cost-effectiveness reported in the literature is very variable and no studies have been found carried out in our country. Even with the most satisfactory results taken from the international literature, its cost-effectiveness has values that are considered close to maximum, even in wealthy countries. It is possible that this profile would be more adverse in developing countries, which forces to evaluate its coverage, taking into account the use of resources in each health system.

Authors' methods: Overview

Project Status: Completed

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

Year Published: 2006

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)