August 21, 2007Annals of Internal Medicine
Systematic Review: Implantable Cardioverter Defibrillators for Adults with Left Ventricular Systolic Dysfunction
Key result
Implantable cardioverter defibrillators reduced all-cause mortality by 20% (95% CI, 10-29%) in RCTs and 46% (95% CI, 32-57%) in observational studies of adults with LV systolic dysfunction.
Why the study?
Do implantable cardioverter defibrillators reduce all-cause mortality in adult patients with left ventricular systolic dysfunction?
Population
105,467 adult patients with left ventricular systolic dysfunction from 12 RCTs and 76 observational studies.
Design
Systematic_review
Authors
Discussion
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Implication
ICDs merit consideration for mortality reduction in LV systolic dysfunction; confirms RCT benefit and extends it to real-world populations.
Key Points
- To summarize the benefits and harms of implantable cardioverter defibrillators in adults with left ventricular systolic dysfunction.
- Systematic review of literature from 1980 to 2007, including both randomized controlled trials and observational studies.
- Analysis of 12 RCTs involving 8516 patients and 76 observational studies involving 96,951 patients.
- Data extraction performed independently by two reviewers. The outcome measures included mortality, complications, and device effectiveness.
- ICDs reduced all-cause mortality by 20% in RCTs (95% CI, 10% to 29%) and by 46% in observational studies (95% CI, 32% to 57%).
- Death associated with ICD implantation occurred in 1.2% of procedures (95% CI, 0.9% to 1.5%).
- Complication rates included 1.4 device malfunctions, 1.5 lead problems, and 0.6 site infections per 100 patient-years.
Study Design
Type
Systematic Review (n=105,467)
Structured PICO
Do implantable cardioverter defibrillators reduce all-cause mortality in adult patients with left ventricular systolic dysfunction?
P
Population
105,467 adult patients with left ventricular (LV) systolic dysfunction (86% NYHA class II or III) from 12 RCTs (n=8,516) and 76 observational studies (n=96,951).
I
Intervention
Implantable cardioverter defibrillators (ICDs)
O
Outcome
All-cause mortalityhard clinical
Main Result
Effect estimate: 20% reduction (95% CI 10% to 29%)
Implantable cardioverter defibrillators are efficacious in reducing all-cause mortality for adult patients with left ventricular systolic dysfunction, with benefits extending to nontrial populations despite known device-related complications.
Limitations
- Studies were of short duration and infrequently reported nonfatal outcomes.
- Few studies evaluated dual-chamber ICDs.
- Lack of individual-patient data prevents identification of subgroup-specific effects.
- Studies were of short duration and infrequently reported nonfatal outcomes
- Few studies evaluated dual-chamber ICDs
- Lack of individual-patient data prevents identification of subgroup-specific effects
Cite This Study
Ezekowitz et al. (2007) conducted a systematic review in Left ventricular systolic dysfunction (n=105,467). Implantable cardioverter defibrillators (ICDs) was evaluated on All-cause mortality (20% reduction, 95% CI 10% to 29%). Implantable cardioverter defibrillators reduced all-cause mortality by 20% (95% CI, 10-29%) in RCTs and 46% (95% CI, 32-57%) in observational studies of adults with LV systolic dysfunction.