Surreal illustration of a heart with tangled wires and a defibrillator, symbolizing atrial fibrillation and heart failure.

AF & Heart Failure: Decoding the ICD Impact

Kai Mendoza in Health & Wellness December 2025 • 4 min read.

"Is there a link between atrial fibrillation, heart failure, and implantable cardioverter-defibrillators?"

Atrial fibrillation (AF), a common heart rhythm disorder, is significantly more prevalent in individuals with heart failure (HF). While AF is known to increase the risk of HF, the relationship becomes even more complex when patients have an implantable cardioverter-defibrillator (ICD). ICDs are designed to prevent sudden cardiac death in at-risk individuals. But the interplay between AF, HF, and ICD therapies remains a subject of considerable debate and research.

The core of the issue lies in understanding whether AF independently worsens outcomes for HF patients with ICDs, or if it simply marks more advanced heart disease. Studies have presented conflicting results, leading to uncertainty about the true impact of AF in this specific patient population. Adding to the complexity, ICD therapies themselves, both appropriate and inappropriate, are associated with poorer prognoses.

To shed light on this complex relationship, a systematic review and meta-analysis was conducted, pooling data from multiple studies. This analysis sought to provide a clearer picture of how a history of AF impacts mortality and the occurrence of ICD therapies in patients with heart failure and reduced ejection fraction (HFrEF) who have an ICD.

Decoding the Link: AF, Heart Failure, and ICD Outcomes

Surreal illustration of a heart with tangled wires and a defibrillator, symbolizing atrial fibrillation and heart failure.

Researchers conducted a thorough search of medical literature through November 2016, identifying 62 studies involving 227,998 patients. These studies explored the connection between AF and various outcomes in HF patients with ICDs. The analysis focused on three key areas: all-cause mortality, appropriate ICD therapies (shocks or anti-tachycardia pacing), and inappropriate ICD therapies.

The meta-analysis revealed a significant association between a history of AF and adverse outcomes in HF patients with ICDs. Key findings included:

Increased Mortality: HF patients with a history of AF had a 42% higher risk of all-cause mortality.
Appropriate ICD Therapies: AF patients faced a higher risk of receiving appropriate ICD therapies.
Inappropriate ICD Therapies: These patients also had a significantly elevated risk of inappropriate ICD interventions.

These results highlight that AF history is statistically associated with adverse clinical outcomes in ICD-implanted HF patients. Patients with AF are at higher risk of mortality and require more ICD interventions (both appropriate and inappropriate) compared to those without AF. Further research is required to determine if AF independently affects HF prognosis or if it marks HF severity.

The Big Picture: Implications and Future Directions

This comprehensive review reinforces the importance of atrial fibrillation as a critical factor in managing heart failure patients with ICDs. The increased risks of mortality and ICD interventions highlight the need for proactive strategies to address AF in this population.

While the study clarifies the association, it also raises important questions about the nature of the relationship. Is AF simply a marker of more severe heart failure, or does it actively contribute to poorer outcomes? Further research is needed to dissect the independent impact of AF.

Moving forward, better characterization and detailed phenotyping of HF patients with ICDs are essential. This would allow for the identification of HF patients who would benefit from surveillance of AF prevention and also aggressive rhythm control.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1093/ehjqcco/qcy054, Alternate LINK

Title: Association Between Atrial Fibrillation And Patient-Important Outcomes In Heart Failure Patients With Implantable Cardioverter-Defibrillators: A Systematic Review And Meta-Analysis

Subject: Cardiology and Cardiovascular Medicine

Journal: European Heart Journal - Quality of Care and Clinical Outcomes

Publisher: Oxford University Press (OUP)

Authors: Katerina K Naka, George Bazoukis, Aris Bechlioulis, Panagiotis Korantzopoulos, Lampros K Michalis, Evangelia E Ntzani

Published: 2018-11-21

Everything You Need To Know

Is there a direct relationship between atrial fibrillation, heart failure, and implantable cardioverter-defibrillators?

Yes, there is a significant link between Atrial Fibrillation (AF), Heart Failure (HF), and Implantable Cardioverter-Defibrillators (ICDs). Patients with both AF and HF who have ICDs face increased risks. Specifically, those with a history of AF have a higher risk of all-cause mortality, and are more likely to require both appropriate and inappropriate ICD therapies. This highlights the importance of addressing AF in HF patients with ICDs.

How does Atrial Fibrillation (AF) impact patients with Heart Failure (HF) who have Implantable Cardioverter-Defibrillators (ICDs)?

Atrial Fibrillation (AF) is a common heart rhythm disorder, and its presence significantly complicates the management of Heart Failure (HF) patients with Implantable Cardioverter-Defibrillators (ICDs). AF is more prevalent in individuals with HF. The combination of these conditions, along with ICDs, leads to a complex interplay affecting patient outcomes. The research indicates that patients with a history of AF have a significantly higher risk of mortality, and are also more likely to experience both appropriate and inappropriate ICD interventions.

What role do Implantable Cardioverter-Defibrillators (ICDs) play in the context of Atrial Fibrillation (AF) and Heart Failure (HF)?

An Implantable Cardioverter-Defibrillator (ICD) is a device designed to prevent sudden cardiac death by delivering electrical shocks or anti-tachycardia pacing to correct life-threatening heart rhythms. In the context of Atrial Fibrillation (AF) and Heart Failure (HF), ICDs are implanted in patients at risk. The presence of AF in patients with ICDs and HF introduces additional complexity. ICDs can deliver both appropriate and inappropriate therapies, and the research indicates that patients with a history of AF are at higher risk of receiving these interventions.

What were the key findings regarding mortality in patients with Atrial Fibrillation (AF), Heart Failure (HF), and Implantable Cardioverter-Defibrillators (ICDs)?

The study revealed that Heart Failure (HF) patients with a history of Atrial Fibrillation (AF) and an Implantable Cardioverter-Defibrillator (ICD) experienced a 42% higher risk of all-cause mortality. This means that, statistically, a larger percentage of these patients died compared to HF patients with ICDs who did not have a history of AF. This finding underscores the need for proactive management strategies targeting AF in HF patients with ICDs to improve survival rates.

What are inappropriate ICD therapies, and how are they related to Atrial Fibrillation (AF) in patients with Heart Failure (HF)?

Inappropriate ICD therapies refer to interventions delivered by the Implantable Cardioverter-Defibrillator (ICD) that are not needed or are triggered by non-life-threatening arrhythmias. The meta-analysis found that patients with a history of Atrial Fibrillation (AF) and Heart Failure (HF) were at an elevated risk of receiving inappropriate ICD therapies. This means the ICD might deliver a shock or pacing when it is not clinically necessary, which can lead to complications and negatively affect the patient's quality of life. The research highlights the need to manage AF to reduce the likelihood of these unnecessary interventions.