Implantable cardioverter-defibrillator (ICD)
An ICD is a small device that a surgeon places in the chest. It is programmed to detect a dangerous heart rhythm or a cardiac arrest without help, and then gives a strong electric shock to end the rhythm or restart the heart. Some ICDs also work as pacemakers. In SCD-HeFT, people with NYHA class II or III heart failure and an ejection fraction of 35% or less had a lower risk of death with an ICD than with placebo. In DANISH, people with symptomatic systolic heart failure (ejection fraction 35% or less) not caused by coronary artery disease did not have a significantly lower rate of death from any cause with an ICD than with usual care, although sudden cardiac death was less frequent.
Also called ICD · Implanted cardioverter defibrillator
- Technology
- In this atlas
Overview
Technical summary
A US government health page also describes wearable cardioverter defibrillators, which it presents as battery-powered vests. SCD-HeFT (NCT00000609; PubMed 15659722): 2521 patients, hazard ratio for death 0.77 (97.5% CI 0.62 to 0.96) with a conservatively programmed, shock-only, single-lead ICD against placebo, and 1.06 (97.5% CI 0.86 to 1.30) with amiodarone. DANISH (NCT00542945; PubMed 27571011): 1116 patients, 21.6% against 23.4% died (hazard ratio 0.87, 95% CI 0.68 to 1.12), and sudden cardiac death 4.3% against 8.2% (hazard ratio 0.50, 95% CI 0.31 to 0.82). MeSH D017147 (Defibrillators, Implantable).
How it works
A device placed in the chest that detects a life-threatening rhythm or a cardiac arrest on its own and sends an electric charge to stop the rhythm or restart the heart (US government health page).
Strengths
- In SCD-HeFT, ICD therapy was associated with a 23 percent lower risk of death than placebo in patients with NYHA class II or III heart failure and an ejection fraction of 35 percent or less (hazard ratio 0.77; 97.5% CI 0.62 to 0.96).
- In DANISH, sudden cardiac death, a secondary outcome, was less frequent with an ICD (4.3 percent against 8.2 percent; hazard ratio 0.50; 95% CI 0.31 to 0.82).
Limitations
- In DANISH the primary outcome, death from any cause, did not differ significantly (hazard ratio 0.87; 95% CI 0.68 to 1.12), and device infection occurred in 4.9 percent of the ICD group against 3.6 percent of the control group (P=0.29).
- The SCD-HeFT ICD was conservatively programmed, shock-only and single-lead, and the abstract says results varied by NYHA class. PubMed links an erratum to the SCD-HeFT paper that was not read.
- Both trials studied heart failure with an ejection fraction of 35 percent or less; neither abstract covers other groups.
Required infrastructure
- Surgical implantation and device follow-up. A US government health page says ICDs are surgically placed in the chest; neither trial abstract describes follow-up care.
Claims and evidence
Context Adults with NYHA class II or III congestive heart failure and a left ventricular ejection fraction of 35 percent or less (SCD-HeFT)
- Recipient
- Adult
- Population
- Patients with New York Heart Association class II or III congestive heart failure and a left ventricular ejection fraction of 35 percent or less (abstract and registry wording). The abstract gives a median ejection fraction of 25 percent; heart failure was ischemic in 52 percent and nonischemic in 48 percent.
- Care setting
- Not stated in the abstract or the registry record.
- Geography
- The registry record lists no study locations.
- Life stage
- Registry age limits are 19 to 90 years.
- Follow-up
- Median follow-up was 45.5 months (abstract). The registry gives a completion date of 2005-04.
Eligibility: 3 inclusion criteria; exclusion criteria not stated
- Included
- NYHA class II or III congestive heart failure
- Left ventricular ejection fraction of 35 percent or less
- Age 19 to 90 years (registry)
- Excluded
- None stated
In SCD-HeFT, 2521 patients with New York Heart Association class II or III congestive heart failure and a left ventricular ejection fraction of 35 percent or less were randomly assigned to conventional therapy plus placebo (847 patients), conventional therapy plus amiodarone (845 patients), or conventional therapy plus a conservatively programmed, shock-only, single-lead ICD (829 patients). Placebo and amiodarone were given in a double-blind fashion. The primary end point was death from any cause, and median follow-up was 45.5 months. There were 244 deaths (29 percent) in the placebo group, 240 (28 percent) in the amiodarone group and 182 (22 percent) in the ICD group. Compared with placebo, amiodarone was associated with a similar risk of death (hazard ratio 1.06; 97.5 percent confidence interval 0.86 to 1.30; P=0.53), and ICD therapy with a decreased risk of death of 23 percent (hazard ratio 0.77; 97.5 percent confidence interval 0.62 to 0.96; P=0.007) and an absolute decrease in mortality of 7.2 percentage points after five years in the overall population. Results did not vary by ischemic or nonischemic cause of heart failure but did vary by NYHA class.
Source problem. A cited source is corrected. Check the sources before relying on this claim.
Applies to Adult- Patients with New York Heart Association class II or III congestive heart failure and a left ventricular ejection fraction of 35 percent or less (abstract and registry wording). The abstract gives a median ejection fraction of 25 percent; heart failure was ischemic in 52 percent and nonischemic in 48 percent.
- Not stated in the abstract or the registry record.
- The registry record lists no study locations.
- Registry age limits are 19 to 90 years.
- Certainty method
- Not assessed
- Limitations
- Abstract of the 2005 report only; the full text was not read (NEJM pages return HTTP 403 to scripts). PubMed links an erratum (a correction) (N Engl J Med 2005 May 19;352(20):2146) whose text was not read, so the numbers may not match the corrected paper. The abstract says placebo and amiodarone were double-blind and does not describe masking of the ICD group. The ICD was a conservatively programmed, shock-only, single-lead device, so the result is not evidence about other programming. The abstract says results varied by NYHA class but gives no figures for it. The registry record lists no results and no study locations.
- Last checked
- 2026-10-15
- Next evidence check due
- Not scheduled
Sources and citations (18)
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Background Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, BACKGROUND, sentence 1
- How it applies
- Background stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, BACKGROUND, sentence 2
- How it applies
- Background stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, METHODS, sentence 1, fragment 1 of 3
- How it applies
- Design, population or outcome definition in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, METHODS, sentence 1, fragment 2 of 3
- How it applies
- Design, population or outcome definition in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, METHODS, sentence 1, fragment 3 of 3
- How it applies
- Design, population or outcome definition in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, METHODS, sentence 2
- How it applies
- Design, population or outcome definition in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, METHODS, sentence 3
- How it applies
- Design, population or outcome definition in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 1
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 2
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 3
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 4, fragment 1 of 2
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 4, fragment 2 of 2
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 5, fragment 1 of 3
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 5, fragment 2 of 3
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 5, fragment 3 of 3
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, RESULTS, sentence 6
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, CONCLUSIONS, sentence 1, fragment 1 of 2
- How it applies
- The authors' conclusion in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure
- Locator
- Abstract, CONCLUSIONS, sentence 1, fragment 2 of 2
- How it applies
- The authors' conclusion in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Corrected
- Snapshot hash
9e02e8268dadfb84fc08a78f82aa246eadeacc3c6916539dc5b812d2f6d96660- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
Context Adults with symptomatic systolic heart failure not caused by coronary artery disease (DANISH)
- Recipient
- Adult
- Population
- Patients with symptomatic systolic heart failure (left ventricular ejection fraction of 35 percent or less) not caused by coronary artery disease. In both groups 58 percent received cardiac resynchronization therapy (abstract). The registry also requires NYHA class II to III (class IV accepted if a biventricular pacemaker is planned) and NT-proBNP above 200 pg/ml.
- Care setting
- Not stated in the abstract. The registry calls the study multicenter in its title and lists one location, in Denmark.
- Geography
- Denmark (the one country in the registry record).
- Life stage
- Registry minimum age is 18 years; the registry gives no maximum age.
- Follow-up
- Median follow-up was 67.6 months (abstract). The registry gives 5 years as the primary outcome time frame.
Eligibility: 5 inclusion criteria; 8 exclusion criteria
- Included
- Age 18 years or older at screening (registry)
- Documented non-ischemic heart failure with a left ventricular ejection fraction of 35 percent or less (registry)
- NYHA class II to III; class IV accepted if a biventricular pacemaker is planned (registry)
- NT-proBNP above 200 pg/ml (registry)
- Written informed consent (registry)
- Excluded
- Uncorrected congenital heart disease or valve obstruction, obstructive cardiomyopathy, active myocarditis, constrictive pericarditis, untreated thyroid disease, adrenal insufficiency or active vasculitis (registry)
- On the urgent waiting list for a heart transplant (the non-urgent list is allowed)
- Recipient of a major organ transplant
- Malignancy treated or present within 6 months before randomisation, with listed exceptions
- Known HIV with an expected survival under 5 years because of HIV
- Renal failure treated with dialysis
- Alcohol or illicit drug abuse disorder in the last 3 months by self-report
- Any condition that in the investigator's opinion puts the subject at significant risk or interferes with participation, and unwillingness to take part
In DANISH, a randomized, controlled trial, 556 patients with symptomatic systolic heart failure (left ventricular ejection fraction of 35 percent or less) not caused by coronary artery disease were assigned to receive an ICD and 560 were assigned to usual clinical care; in both groups 58 percent received cardiac resynchronization therapy. The primary outcome was death from any cause. After a median follow-up of 67.6 months, the primary outcome had occurred in 120 patients (21.6 percent) in the ICD group and in 131 patients (23.4 percent) in the control group (hazard ratio 0.87; 95 percent confidence interval 0.68 to 1.12; P=0.28). Sudden cardiac death, a secondary outcome, occurred in 24 patients (4.3 percent) in the ICD group and in 46 patients (8.2 percent) in the control group (hazard ratio 0.50; 95 percent confidence interval 0.31 to 0.82; P=0.005). Device infection occurred in 27 patients (4.9 percent) in the ICD group and in 20 patients (3.6 percent) in the control group (P=0.29). The authors conclude that prophylactic ICD implantation was not associated with a significantly lower long-term rate of death from any cause than usual clinical care.
Applies to Adult- Patients with symptomatic systolic heart failure (left ventricular ejection fraction of 35 percent or less) not caused by coronary artery disease. In both groups 58 percent received cardiac resynchronization therapy (abstract). The registry also requires NYHA class II to III (class IV accepted if a biventricular pacemaker is planned) and NT-proBNP above 200 pg/ml.
- Not stated in the abstract. The registry calls the study multicenter in its title and lists one location, in Denmark.
- Denmark (the one country in the registry record).
- Registry minimum age is 18 years; the registry gives no maximum age.
- Certainty method
- Not assessed
- Limitations
- Abstract of the 2016 report only; the full text was not read (NEJM pages return HTTP 403 to scripts). The primary outcome did not differ significantly between the groups. The sudden-cardiac-death result is a secondary outcome, and the abstract does not say how it was adjusted for multiple comparisons. The trial studied heart failure not caused by coronary artery disease and says nothing about heart failure caused by coronary artery disease. The abstract names Medtronic and others as funders. PubMed lists no erratum for this record. The registry record holds no results.
- Last checked
- 2026-10-15
- Next evidence check due
- Not scheduled
Sources and citations (17)
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Background Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, BACKGROUND, sentence 1
- How it applies
- Background stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, BACKGROUND, sentence 2, fragment 1 of 2
- How it applies
- Background stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, BACKGROUND, sentence 2, fragment 2 of 2
- How it applies
- Background stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, BACKGROUND, sentence 3
- How it applies
- Background stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, METHODS, sentence 1, fragment 1 of 2
- How it applies
- Design, population or outcome definition in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, METHODS, sentence 1, fragment 2 of 2
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ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, METHODS, sentence 2
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- Design, population or outcome definition in the abstract.
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- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, METHODS, sentence 3
- How it applies
- Design, population or outcome definition in the abstract.
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- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, METHODS, sentence 4
- How it applies
- Design, population or outcome definition in the abstract.
- Retrieved
- Source effective date
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- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, RESULTS, sentence 1, fragment 1 of 2
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- Result stated in the abstract.
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ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, RESULTS, sentence 1, fragment 2 of 2
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
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- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, RESULTS, sentence 2, fragment 1 of 2
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, RESULTS, sentence 2, fragment 2 of 2
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
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- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Supports Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, RESULTS, sentence 3
- How it applies
- Result stated in the abstract.
- Retrieved
- Source effective date
- Not reported
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- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, CONCLUSIONS, sentence 1, fragment 1 of 2
- How it applies
- The authors' conclusion in the abstract.
- Retrieved
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- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, CONCLUSIONS, sentence 1, fragment 2 of 2
- How it applies
- The authors' conclusion in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
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Background Defibrillator Implantation in Patients with Nonischemic Systolic Heart Failure
- Locator
- Abstract, CONCLUSIONS, sentence 2
- How it applies
- The authors' conclusion in the abstract.
- Retrieved
- Source effective date
- Not reported
- Source state
- Current
- Snapshot hash
ed86c7418fab9245ebefc0371dc41a8479fede9fdf2b4ceb7b831b4e91ef4dc1- Reuse basis
- PubMed record fetched through NCBI E-utilities. Only the hash of the bytes is kept, because publisher copyright may apply to the abstract (PubMed disclaimer, fetched 2026-10-15 as ck-pubmed-disclaimer.html, hash only). Short factual quotations under 25 words, with the citation. Public text is quote, following Ben's decision of 2026-10-13 (medical-atlas-core issue 2) for PubMed and other NLM records.
Clinical links
Each link reports what one cited claim says about one population. "Evaluated for" means studied, not shown to work. These links do not show that anything is effective or right for you.
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Claim, not a settled fact Compared with placebo and amiodarone in SCD-HeFT: Heart failure
Applies to Adult- Patients with New York Heart Association class II or III congestive heart failure and a left ventricular ejection fraction of 35 percent or less (abstract and registry wording). The abstract gives a median ejection fraction of 25 percent; heart failure was ischemic in 52 percent and nonischemic in 48 percent.
- Not stated in the abstract or the registry record.
- The registry record lists no study locations.
- Registry age limits are 19 to 90 years.
In SCD-HeFT, 2521 patients with New York Heart Association class II or III congestive heart failure and a left ventricular ejection fraction of 35 percent or less were randomly assigned to conventional therapy plus placebo (847 patients), conventional therapy plus amiodarone (845 patients), or conventional therapy plus a conservatively programmed, shock-only, single-lead ICD (829 patients). Placebo and amiodarone were given in a double-blind fashion. The primary end point was death from any cause, and median follow-up was 45.5 months. There were 244 deaths (29 percent) in the placebo group, 240 (28 percent) in the amiodarone group and 182 (22 percent) in the ICD group. Compared with placebo, amiodarone was associated with a similar risk of death (hazard ratio 1.06; 97.5 percent confidence interval 0.86 to 1.30; P=0.53), and ICD therapy with a decreased risk of death of 23 percent (hazard ratio 0.77; 97.5 percent confidence interval 0.62 to 0.96; P=0.007) and an absolute decrease in mortality of 7.2 percentage points after five years in the overall population. Results did not vary by ischemic or nonischemic cause of heart failure but did vary by NYHA class.Source problem. A cited source is corrected. Check the sources before relying on this claim.
Limitations. Abstract of the 2005 report only; the full text was not read (NEJM pages return HTTP 403 to scripts). PubMed links an erratum (a correction) (N Engl J Med 2005 May 19;352(20):2146) whose text was not read, so the numbers may not match the corrected paper. The abstract says placebo and amiodarone were double-blind and does not describe masking of the ICD group. The ICD was a conservatively programmed, shock-only, single-lead device, so the result is not evidence about other programming. The abstract says results varied by NYHA class but gives no figures for it. The registry record lists no results and no study locations.
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Claim, not a settled fact Compared with usual care in heart failure not caused by coronary artery disease (DANISH): Heart failure
Applies to Adult- Patients with symptomatic systolic heart failure (left ventricular ejection fraction of 35 percent or less) not caused by coronary artery disease. In both groups 58 percent received cardiac resynchronization therapy (abstract). The registry also requires NYHA class II to III (class IV accepted if a biventricular pacemaker is planned) and NT-proBNP above 200 pg/ml.
- Not stated in the abstract. The registry calls the study multicenter in its title and lists one location, in Denmark.
- Denmark (the one country in the registry record).
- Registry minimum age is 18 years; the registry gives no maximum age.
In DANISH, a randomized, controlled trial, 556 patients with symptomatic systolic heart failure (left ventricular ejection fraction of 35 percent or less) not caused by coronary artery disease were assigned to receive an ICD and 560 were assigned to usual clinical care; in both groups 58 percent received cardiac resynchronization therapy. The primary outcome was death from any cause. After a median follow-up of 67.6 months, the primary outcome had occurred in 120 patients (21.6 percent) in the ICD group and in 131 patients (23.4 percent) in the control group (hazard ratio 0.87; 95 percent confidence interval 0.68 to 1.12; P=0.28). Sudden cardiac death, a secondary outcome, occurred in 24 patients (4.3 percent) in the ICD group and in 46 patients (8.2 percent) in the control group (hazard ratio 0.50; 95 percent confidence interval 0.31 to 0.82; P=0.005). Device infection occurred in 27 patients (4.9 percent) in the ICD group and in 20 patients (3.6 percent) in the control group (P=0.29). The authors conclude that prophylactic ICD implantation was not associated with a significantly lower long-term rate of death from any cause than usual clinical care.Limitations. Abstract of the 2016 report only; the full text was not read (NEJM pages return HTTP 403 to scripts). The primary outcome did not differ significantly between the groups. The sudden-cardiac-death result is a secondary outcome, and the abstract does not say how it was adjusted for multiple comparisons. The trial studied heart failure not caused by coronary artery disease and says nothing about heart failure caused by coronary artery disease. The abstract names Medtronic and others as funders. PubMed lists no erratum for this record. The registry record holds no results.
Record details
- Record id
cardio:implantable-cardioverter-defibrillator- Content hash
143844a186bcbca00924455aa353b8ffba10c4474ed92e406e289417d08e3782