Atrial Fibrillation in Heart Failure - Healthcare and Medical News for Atlanta Physicians

Atrial fibrillation (AF) and heart failure (HF) are intertwined at so many levels, and each is both a major cause of and result of the other. This interplay is complex and incorporates many pathological mechanisms, but needless to say, the patient presenting with both AF and HF is an important cohort worth a more detailed review.

One of the key issues is trying to sort out whether the primary issue is AF or HF. It is well-known that AF with rapid rates can cause a specific entity called tachycardia-induced cardiomyopathy. The relative good news in this situation is that the LV dysfunction in this circumstance is typically reversible with adequate rate control (Shinbane JS, 1997). The timing of tachycardia-mediated cardiomyopathy is variable, but onset of LV dysfunction appears to occur over weeks, and once rates are controlled, LV function usually returns to normal within a month.

There are numerous other interplays in both directions. AF results in electrical remodeling of the atria, which can subsequently lead to structural remodeling, scar formation, atrial dilation, mitral annular dilation, mitral regurgitation, and thus increased risk of HF. The faster rates and irregularity may also impact LV function. On the flip side, HF results in elevated afterload, annular dilation, increased mitral regurgitation, atrial enlargement, atrial scar formation, and thus increased risk of AF. Neurohormal activation and calcium dysregulation serves as additional mediating factor (Gopinathannair R, 2021). AF has an association with both HF with preserved and reduced LV function, though patients with LV dysfunction have been studied more rigorously.

Initial therapy for patients with AF and HF focuses on the importance of heart rate and management of acute heart failure. Acute rate control, appropriate diuresis in the setting of volume overload, and guideline-directed medical therapy for HF are paramount. In many cases, this initial period of therapy may also help tease out whether the AF or HF is the greater primary culprit.

Rhythm Control

Shortly after and sometimes during the acute management phase, a decision will need to be made about a rhythm control vs rate control strategy. While the AFFIRM study for years has allowed physicians to consider both options with relative equipoise, the extensive data from recent trials clearly shows that rhythm control is superior to rate control (Kirchhof P, 2020). Recent advances in AF ablation technology making the procedure safer and more accessible further elevate rhythm control. Finally, in the setting of HF, there is now a robust set of randomized trials (particularly CASTLE-HF and CASTLE-HTx) demonstrating mortality benefit with AF ablation and rhythm control (Marrouche NF, 2018; Sohns C, 2023). Thus, for patients with AF and HF, the default strategy should be for rhythm control, predominantly with AF ablation when feasible.

Despite this plethora of data showing superiority of rhythm control, we do know that rhythm control has only modest success rates, and in some cases, AF ablation(s) and antiarrhythmic drugs (AADs) can be futile. In such cases, the real risk of complications or side effects could potentially outweigh any benefit. What factors can be used to help gauge whether aggressive AF rhythm control may no longer by worthwhile? Severely enlarged LA, long duration of AF, and extensive atrial scar on cardiac imaging may be markers that the chance of restoring or maintaining SR is lower (Charitakis E, 2023). Patient-related factors such as the patient’s age, frailty, and comorbidities may indicate a cohort in whom the procedural or AAD complication risk is elevated. Finally, for patients with adequate rate control, lack of symptoms, and LV dysfunction clearly preceding AF, the benefit of rhythm control may be muted or nonexistent. It is important to consider all three groups of factors to suggest when rate control alone may in fact be preferable.

The outcome of rhythm control is of course to try to be in sinus rhythm as much as possible. Previous studies have focused on time until AF recurrence, but the endpoint that matters is reduction in AF burden. Substudy data from CASTLE-HF and others highlight that when AF burden is reduced, the outcomes are better, with benefit noted when AF burden was <40% or more so at <5% (Brachmann J, 2021; Schwennesen HT, 2023). Of course, those with reduction in AF burden may be selecting the patients with less severe HF in some other capacity, but the data are compelling that lower AF burden is beneficial.

Rate Control

Rate control remains a cornerstone of management in AF, both acutely and long-term, especially when rhythm control is not an option. It should always be front and center during the acute management period, and bringing the rate down will improve HF management and symptoms tremendously. In the acute setting for AF rate control, beta blockers and nondihydropyridine calcium channel blockers are the usual first-line agents. Unfortunately, in the setting of HF, calcium channel blockers are contraindicated, and beta blockers may be limited by concurrent hypotension. The aggressiveness of rate control in the acute setting is largely dependent on the clinical circumstance, and in the acute setting, some degree of tachycardia may be appropriate even if the patient is in sinus rhythm.

What about digoxin? There are times that additional rate control is required beyond what can be achieved with beta blockers alone. This is where the question of digoxin is often raised. Although there is much historic data which has suggested digoxin may be associated with increased mortality, it is crucial to remember that this data is all retrospective and fraught with limited applicability. There are no randomized studies to answer the question of whether digoxin to help rate control is better or worse than the next best options which often would be amiodarone or pace and ablate. This is often a complex clinical situation and requires nuanced decision making, not likely to be readily answered in a future randomized control trial. There is, however, the very recent DIGIT-HF trial which assessed in a randomized fashion adding digoxin to standard medical therapy for HF, and this showed a net benefit (Bavendiek 2025). Thus, it is quite appropriate to utilize digoxin for rate control in AF and HF when needed.

Rate control to a target HR can be helpful especially in the outpatient setting. Although studies of potential lenient rate control approaches have suggested acceptable outcomes for patients with AF, when considering patients with concurrent HF, retrospective data supports more aggressive rate control, ideally to resting HR < 80 bpm (Hess PL, 2020). Unfortunately, patients whose HRs are more easily controlled are likely to have better outcomes, so this may be collider bias, thus clinical discretion is necessary when considering HR targets in AF and HF.

An important factor to remember is that sometimes the best way to achieve rate control is via rhythm control. That can be via urgent or expedited cardioversion, with or without antiarrhythmic drugs, or via an expedited AF ablation procedure. Promoting early AF ablation can often avoid prolonged challenges in rate control.

Pace and Ablate

Finally, it is worth reviewing a tried and true strategy for decades. Prior to AF ablation, when maintenance of SR was even more difficult, in the setting of rapidly conducting AF with HF, numerous studies demonstrated a benefit with AV node ablation and pacemaker implantation (Brignole 2021). Pacing advances including cardiac resynchronization therapy and more recently, conduction system pacing, make long-term ventricular pacing less harmful. These advances allow the pace and ablate strategy to provide the benefit of definitive rate control with much lower risk of downside. When patients already have or otherwise need a device regardless, that lends even more support for considering this approach. When rhythm control is unsuccessful or patients are not a good candidate, then pace and ablate can help with recovery of associated LV dysfunction.

Future developments may continue to enhance AF ablation strategies such that more advanced disease can still be successfully ablated. Heart failure therapies continue to evolve. At an upstream level, the rapid progress of GLP-1 drugs, the resulting weight loss, and improvement in numerous cardiovascular markers, will hopefully lead to a lower overall incidence of both AF and HF. The growing emphasis on risk factor modification, particular improved diet, exercise, and reduced alcohol intake, though challenging for many patients, remains a cornerstone of preventing future AF cases.

In summary, atrial fibrillation and heart failure are often found together in the clinical setting, and it is usually the case that through multiple pathophysiological pathways, they each are major contributors and drivers of each other. It then becomes important to manage both together, and when AF is promoting HF, more aggressive AF treatment is warranted. This is highlighted by a critical role for rhythm control using AF ablation in particular for most patients when not otherwise contraindicated. When rhythm control is unsuccessful or not an option, stricter rate control including pace and ablate strategies should be pursued. When AF is appropriately managed, patients demonstrate marked improvement in heart failure, and in some cases, clear benefits in mortality outcomes.

References

Bavendiek U, et al. “Digitoxin in Patients with Heart Failure and Reduced Ejection Fraction.” N Eng J Med 2025; 393: 1155-1165.
Brachmann J, et al. “Atrial Fibrillation Burden and Clinical Outcomes in Heart Failure: The CASTLE-AF Trial.” JACC Clin Electrophysiol 2021; 7 (5): 594-603.
Brignole M, et al. “AV Junction Ablation and Cardiac Resynchronization for Patients with Permanent Atrial Fibrillation and Narrow QRS: The APAF-CRT Mortality Trial.” Eur Heart J 2021; 42 (46): 4731-4739.
Charitiakis E, et al. “Predictors of Recurrence After Catheter Ablation in Electrical Cardioversion of Atrial Fibrillation: An Umbrella Review of Meta-Analyses.” Europace 2023; 25 (1): 40-48.
Gopinathannair R, et al. “Managing Atrial Fibrillation in Patients with Heart Failure and Reduced Ejection Fraction.” Circ: Arrhythm & Electrophysiol 2021; 14 (7): 688-705.
Hess PL, et al. “Strict Versus Lenient Versus Poor Rate Control Among Patients With Atrial Fibrillation and Heart Failure.” Am J Cardiol 2020; 125 (6): 894-900.
Kirchhof P, et al. “Early Rhythm-Control Therapy in Patients with Atrial Fibrillation.” N Engl J Med 2020; 383: 1305-1316.
Marrouche NF, et al. “Catheter Ablation for Atrial Fibrillation with Heart Failure.” N Engl J Med 2018; 378: 417-427.
Shinbane JS, et al. “Tachycardia-induced cardiomyopathy: a review of animal models and clinical studies.” J Am Coll Cardiol 1997; 29 (4): 709-715.
Sohns C, et al. “Catheter Ablation in End-Stage Heart Failure with Atrial Fibrillation.” N Engl J Med 2023; 389: 1380-1389.
Schwennesen HT, et al. “Ablation to Reduce Atrial Fibrillation Burden and Improve Outcomes: JACC Review Topic of the Week.” J Am Coll Cardiol 2023; 82 (10): 1039-1050.

Ashish A. Bhimani, MD, FHRS, FACC

Ashish A. Bhimani, MD, FHRS, FACC is the Chief of Electrophysiology at Piedmont Heart Institute. Prior to joining Piedmont Heart Institute in 2016, he completed his cardiovascular disease and electrophysiology training at University Hospitals in Cleveland and then served on the faculty at University of Texas Medical Branch for 3 years. In addition to a broad-based EP clinical practice, he has a special interest in electrophysiology education and developing system-wide approaches to improving quality of care.