Review Article

Rhythm Control in Heart Failure Patients with Atrial Fibrillation

Register or Login to View PDF Permissions
Permissions× For commercial reprint enquiries please contact Springer Healthcare: ReprintsWarehouse@springernature.com.

For permissions and non-commercial reprint enquiries, please visit Copyright.com to start a request.

For author reprints, please email rob.barclay@radcliffe-group.com.
Information image

  • Views: 1007

  • Likes: 1

  • Downloads: 44

  • Citations: 3

Average (ratings)
No ratings
Your rating

Abstract

AF and heart failure (HF) commonly coexist. Left atrial ablation is an effective treatment to maintain sinus rhythm (SR) in patients with AF. Recent evidence suggests that the use of ablation for AF in patients with HF is associated with an improved left ventricular ejection fraction and lower death and HF hospitalisation rates. We performed a systematic search of world literature to analyse the association in more detail and to assess the utility of AF ablation as a non-pharmacological tool in the treatment of patients with concomitant HF.

Keywords

AF, heart failure, rhythm control, rate control, cardiac ablation,

Disclosure:The authors have no conflicts of interest to declare.

Received:

Accepted:

Published online:

DOI:https://doi.org/10.15420/aer.2020.23

Correspondence Details:William Eysenck, St George’s University Hospitals NHS Foundation Trust, Blackshaw Rd, Tooting, London SW17 0QT, UK. E: william.eysenck@nhs.net

Open Access:

This work is open access under the CC-BY-NC 4.0 License which allows users to copy, redistribute and make derivative works for non-commercial purposes, provided the original work is cited correctly.

Sir James Mackenzie, famous for describing the first mechanistic insights into AF in 1902 using his polygraph, also reported that AF was present in 80–90% of patients who had congestive heart failure (HF) in 1920.1 Today, the conditions are the two ‘epidemics’ of cardiovascular disease.2 They are dominating cardiovascular care and, with increasing longevity, they will become more prevalent and place an even greater burden upon healthcare resources over the coming decades.3, 4 The conditions are inextricably linked in a vicious cycle, with HF promoting the development of AF and vice versa. In addition, each increases the morbidity and mortality associated with the other.5

Despite good progress in the management of AF-related symptoms, there are limited data to compare the benefits of different treatments and international guidelines advocate multiple therapeutic options.6 Traditionally, AF rhythm control involves a combination of antiarrhythmic medical therapy and direct current cardioversion (DCCV). Partly because of the inefficacy of these therapies the ‘rate versus rhythm’ debate has been intense in the aftermath of trials showing that, compared to a rate control strategy, a rhythm control strategy does not reduce mortality or morbidity and is more costly and inconvenient.7, 8

More recently, multiple studies have reported improvements in ‘soft’ end points with catheter ablation while two trials – Catheter Ablation vs Anti-arrhythmic Drug Therapy for Atrial Fibrillation Trial (CABANA; NCT00911508) and Catheter Ablation vs Standard Conventional Treatment in Patients With LV Dysfunction and AF (CASTLE-AF) – have reignited the debate as to whether modern rhythm control therapy can improve prognosis in patients with AF.

This paper is a state-of-the-art review analysing world literature accessed via detailed literature searches utilising PubMed, Web of Science and Scopus to establish the connection between AF and HF in detail and to determine the impact of AF rhythm control on patients with coexisting HF.

Direct Current Cardioversion for AF and Left Ventricular Performance

In 1962, Lown described electrical cardioversion of AF.9 He later won the Nobel Prize for his nuclear weapon non-proliferation work.10 Electrical cardioversion is indicated for patients with AF associated with significant symptoms or as part of a long-term rhythm control strategy. The efficacy and immediacy of DCCV in restoring SR provides valuable insight into the potential benefit of rhythm control on cardiac performance.

Kieny et al. demonstrated that, after successful cardioversion in persistent AF patients with dilated cardiomyopathy, left ventricular ejection fraction (LVEF) improved from 32.1% ±€5.3% to 52.9 ±€9.7%; p<0.001.11 Wall et al. demonstrated an improvement in LVEF of 14.2% in patients with impaired LV function following successful cardioversion (n=108; 95% CI [11.0%–17.4%]; p<0.0001). Furthermore, the benefit was more significant the lower the LVEF. The subgroup analysis of moderately reduced ejection fraction (HFmrEF) showed a mean improvement of 4.24% (n=50; 95% CI [0.3–8.2%]; p=0.03) and the subgroup analysis of reduced ejection fraction (HFrEF) showed a mean improvement of 23.0% (n=58; 95% CI [19.4–26.6%]; p<0.0001).

DCCV successfully restores SR in the majority of patients who undergo the procedure with quoted success rates at the time of the procedure of the order of 85%.12 However, it is widely accepted that DCCV has limited long-term success rate with only 30–40% of patients remaining in SR at the end of 1 year.13 Restoration of SR with DCCV can improve AF-related symptoms, LVEF, exercise capacity and HF symptoms.14,15

Given the greater efficacy of AF ablation and antiarrhythmic drug (AAD) therapy in maintaining SR, it is logical to hypothesise a more substantial role for these interventions in patients with coexisting HF and AF. Despite this, the only indication in international guidelines for catheter and surgical AF ablation (including concomitant open and closed procedures and standalone) remains symptom relief.16

Antiarrhythmic Medication for AF in Heart Failure

Two landmark studies, each with >1,000 patients, have assessed the efficacy of pharmacological rhythm control in patients with concomitant AF and HF (AF-CHF) with HFrEF.17 In the Danish Investigators of Arrhythmia and Mortality on Dofetilide in Congestive Heart Failure (DIAMOND-CHF) trial, 1,518 patients were randomised to receive either dofetilide (n=762) or placebo (n=758). At the conclusion of the trial (12 months follow-up), 65% of patients in the dofetilide arm were in SR versus 30% of patients in the placebo arm. There was no difference in mortality between the two groups, but the dofetilide arm had lower rates of HF hospitalisation than the placebo group.18

In the AF-CHF trial, there was no difference in cardiovascular death when comparing a rate versus rhythm-control strategy with antiarrhythmic medications in 1,376 patients with AF and HFrEF and New York Heart Association (NYHA) classes II–IV (HR 1.06; 95% CI [0.86–1.30]; p=0.59), with similar findings for all-cause mortality and worsening HF.19

A possible explanation for these neutral outcomes is the difficulty in achieving and maintaining SR in patients with HF. In the rhythm control arm of AF-CHF, although 82% or participants were taking amiodarone, 58% had at least one episode of AF during the trial.19 In addition, the potential benefit of SR maintenance with respect to mortality may have been neutralised by harmful effects of AADs.17

Benefits of Rate Control for AF in Heart Failure

A poor rate control resulting in fast ventricular response has been suspected as one of the major determinants of HF in AF patients. Impaired cardiac function can be reversed after restoration of SR and good ventricular rate control achieved as well by using either antiarrhythmic drugs or by atrioventricular (AV) node ablation and pacemaker implantation.2

While the benefit of cardiac resynchronisation therapy (CRT) is established in symptomatic HF patients in SR with LVEF ≤35% and QRS duration of ≥120 ms, its role in patients with coexistent HF and AF is less well defined.20,21 CRT with AV node ablation provides robust rate control and improved ventricular synchrony in AF and requires attention. Three studies have evaluated the impact of AV node ablation on LVEF in 346 CRT-AF patients.22–24 The mean increase in LVEF was 10.3% (95% CI [6.4%–14.2%]) in patients receiving a CRT device combined with AV node ablation. These data suggest an important role for rate control of AF in improving outcomes in HF patients.

Catheter Ablation for AF in Heart Failure

The first data on the impact of curative catheter ablation for AF in HF patients was reported by Hsu et al. in 2004.25 The authors demonstrated that LVEF significantly increased after AF ablation with the greatest improvement within the first 3 months after the procedure. Interestingly, LVEF increased in most of the patients irrespective of whether ventricular rates were poor or well-controlled before ablation, indicating the existence of other factors than a fast ventricular rate for the development of AF-CHF.

In the Comparison of Pulmonary Vein Isolation Versus AV Nodal Ablation With Biventricular Pacing for Patients With Atrial Fibrillation With Congestive Heart Failure (PABA CHF; NCT00599976) study, 41 patients with drug-resistant AF were randomly assigned to pulmonary vein isolation (PVI) and 40 patients to undergo AV node ablation combined with biventricular pacing.26 At 6 months, patients who had undergone PVI had a higher LVEF than those who had received AV node ablation and biventricular pacing (35% versus 28%; p<0.011). Patients undergoing the rhythm control procedure also had better 6-minute walk distance (340 m versus 297 m; p<0.001) than those in the ‘ablate and pace’ strategy. In patients undergoing PVI, 71% remained in SR at 6 months. AV node ablation with biventricular pacing is a robust form of the rate-control strategy and of rate regularisation. PABA CHF showed that PVI, compared to the best possible rate-control and rate-regularisation strategy, provides superior morphological and functional improvements. Potential explanations for LVEF improvement might be the improvement of atrial contractility, maintenance of atrioventricular synchrony, as well as the prevention of high ventricular rates.27

Importance of Sinus Rhythm

A number of recent trials have suggested that SR following AF ablation is associated with improved outcomes in patients with AF.28 Substantial data demonstrate that restoration of SR leads to an improvement in LVEF in AF patients (Table 1).29 Regardless of aetiology, LV systolic dysfunction and HF are associated with a higher risk of death.30 The majority of AF ablation trials use freedom from AF and restoration of SR as their primary endpoints, with procedural success rates of 50–60% after a single procedure and 80–85% after repeat procedures.31 Therefore, it is logical to postulate that, in restoring SR, a successful AF ablation may not only improve LVEF but also reduce the excess mortality associated with concomitant HF.

In studies of catheter ablation of AF, restoration of SR is associated with significant improvements in LVEF, with an 11% increase on average.32 In addition, patients with AF and HF who spend a higher proportion of time in SR experience less severe functional impairment (NYHA class III symptoms in 27 versus 35%; p<0.0001).33

Myocardial Fibrosis in AF and Heart Failure

Atrial fibrosis leads to structural and functional impairment of the left atrium and persistence of AF, and is associated with the development of AF-HF.34,35 Mild pre-ablation left atrial structural remodelling by delayed enhancement MRI (DEMRI) predicts favourable structural and functional reverse remodelling and long-term success after catheter ablation of AF, irrespective of the paroxysmal or persistent nature of AF.34

Despite extensive research addressing the interplay between changes in the atria and AF, relatively few studies provide histological evaluation of the ventricle in patients with AF.36 However, it appears to have a crucial role in the AF-CHF interaction. Ventricular fibrosis may occur secondary to AF as a consequence of rapid ventricular rates, the irregularity of ventricular contraction or activation of the renin–angiotensin–aldosterone system.35,37,38 Myocardial interstitial fibrosis contributes to left ventricular dysfunction leading to the development of HF.39 Successful catheter ablation has been shown to result in reverse remodelling and a regression of diffuse fibrosis in AF-mediated cardiomyopathy providing the pathophysiological explanation for the benefit of ablation in AF-CHF patients.40

Summary of Randomised Trials of Catheter Ablation

Article image
Download

Cardiac MRI offers noninvasive assessment of atrial injury and recovery of active atrial function following AF ablation because of its ability to visualise all segments of the atrial wall during the cardiac cycle.41 Catheter ablation can be associated with sustained atrial dysfunction owing to to ablation-related scarring. Previous studies have demonstrated that the difference between electroanatomic mapping (EAM) ablated area and LGE-MRI scar area was associated with higher AF recurrence after ablation.42 Despite the aforementioned benefits of catheter ablation in AF-CHF, repeat ablation could be associated with more ablation-related scarring and worse outcomes.43,44 This suggests timely treatment of arrhythmia-mediated cardiomyopathy may minimise irreversible ventricular remodelling if SR is restored and multiple AF ablation procedures should be avoided.

Cardiopulmonary Exercise Testing in AF and Sinus Rhythm

Cardiopulmonary exercise testing (CPET) is an important tool to evaluate exercise capacity and predict outcomes in patients with HF.45 It provides an assessment of the integrative exercise responses involving the pulmonary, cardiovascular and skeletal muscle systems, which are not adequately reflected through the measurement of individual organ system function.45 Peak oxygen uptake (VO2 peak) is an important, reproducible facet of exercise performance and has been shown to have high prognostic value in cardiac patients and healthy individuals. VO2 peak is determined by cellular oxygen demand and equates to the maximal rate of oxygen transport. Significant increases in VO2 peak in SR have been demonstrated on CPET in patients who have undergone AF ablation.46 These findings imply that an improvement in haemodynamics in SR improves the rate of oxygen transport and, ultimately, this has the potential to improve prognosis. In addition, VO2 peak is a strong prognostic indicator in chronic HF and is a criterion variable for consideration of cardiac transplantation in such patients.47,48 Among patients with chronic systolic HF, even a modest increase in peak VO2 peak over 3 months has been associated with more favourable outcomes, highlighting the importance of CPET as an investigative tool; it also provides an insight into the favourable haemodynamic effects of restoring SR with an ablation procedure.49

Sleep Studies and Rhythm Control

Another condition strongly associated with AF is sleep-disordered breathing (SDB). Perhaps the most straightforward explanation for the association is that patients with AF and SDB share a number of risk factors and comorbidities, including age, male sex, hypertension, HF and coronary artery disease.

More evidence is emerging of a true physiological connection.50,51 Patients with obstructive sleep apnoea (OSA) have >30% greater risk of AF recurrence after catheter ablation than those without.52–54 However, the efficacy of catheter ablation for AF is similar in patients without obstructive sleep apnoea and those with this condition who are on continuous positive airway pressure treatment.55,56

In an animal model, obesity and acute obstructive apnoea have been shown to interact to promote AF.57 OSA is associated with repetitive forced inspiration against a closed airway which can result in negative intrathoracic pressure leading to an increase in cardiac afterload, larger atrial size and higher wall stress, resulting in atrial remodelling, which predisposes patients to arrhythmia.58

Further recent studies have demonstrated a reduction in nocturnal respiratory events (apnoeas and hypopnoeas) and a reversal of sleep-disordered breathing with restoration of SR using both DCCV and AF ablation procedures at short-term follow-up.55,56 Improving haemodynamic status and cardiac function with restoration of SR could reduce fluid displacement from the lower limbs to the neck region of the body, a key mechanism in the pathogenesis of OSA.59–61 The hazard of mortality in sleep apnoea increases with apnoea severity, highlighting the potential importance of these findings and providing a further, different angle to hypotheses supporting a mortality benefit of SR in patients with AF.62

AF Ablation and Mortality in Heart Failure

A number of studies postulate that AF ablation can reduce mortality. CASTLE-AF is the only randomised clinical trial to date comparing catheter ablation and pharmacological therapy for patients with coexisting HF and AF that measures the ‘hard’ primary endpoints of death and hospitalisation for heart failure.63 Patients had symptomatic paroxysmal or persistent AF, LVEF ≤35%, NYHA class ≥2, with an ICD or CRT with defibrillator implanted. AF ablation was associated with a significantly lower rate of a composite of death and hospitalisation for HF than medical therapy.63 There was also a benefit in all-cause mortality alone, driven by a significantly lower rate of cardiovascular death in the ablation group.

Furthermore, catheter ablation reduced the AF burden, increased the distance walked in 6 minutes and improved the LVEF. On the basis of the data extracted from the memory of the implanted devices, 63.1% of the patients in the ablation group and 21.7% in the medical-therapy group (p<0.001) were in SR at the 60-month follow-up visit and had not had AF recur since the previous follow-up visit (typically at 48 months).63

Heart Rhythm Monitoring Following AF Ablation

Given the benefits of maintenance of SR following AF ablation described, accurate and complete heart rhythm monitoring is imperative. The HRS Expert Consensus Statement set guidelines for catheter ablation trials stating that, after the blanking period, success is defined as ‘freedom from AF, atrial flutter or tachycardia’ and discontinuation of antiarrhythmic medication, that patients should be followed for at least 12 months and, at minimum, should have a 24-hour Holter monitor at 3, 6, 12 and 24 months.16,64

The gold standard of heart rhythm monitoring is beat-to-beat monitoring with implanted devices.65 AF ablation studies employing beat-to-beat monitoring with implanted devices have determined ‘cure’ rates of only 29% for persistent AF, significantly lower than trials that used less stringent monitoring criteria.31, 66 Beat-to-beat monitoring will detect significantly more AF episodes because of the continuous monitoring capabilities of implanted devices. In the absence of large, prospective, randomised studies using beat-to-beat follow up, ablation success remains open to speculation. Beat-to-beat monitoring is particularly important if it is the restoration of SR that is associated with improvement in LV function and provides an argument for all catheter ablation studies to have significantly tighter cardiac monitoring, ideally with implanted devices allowing every heartbeat to be monitored.

Discussion

The main findings of our systematic review are that the pathophysiological benefits from AF ablation stem from successful restoration of SR and this is most likely to be achieved by early intervention. These benefits extend to reversed remodelling of the left cardiac chambers, an improvement in LVEF, an improvement in key, prognostic facets of exercise performance and a reduction in SDB. It is likely that these factors are the drivers for the reduced mortality observed with AF ablation in the recent CASTLE-AF study.

In addition, a large percentage of patients in the general population progress from a paroxysmal form of AF to a persistent or permanent form, limiting the likelihood of successful ablation, suggesting timely treatment of arrhythmia-mediated cardiomyopathy with ablation may minimise irreversible remodelling when SR is restored.

Finally, given the importance of restoration and maintenance of SR following ablation, we propose that AF ablation trials should use stringent heart rhythm monitoring, ideally with implanted devices, allowing monitoring of every heartbeat to document the true impact of ablation on heart rhythm. Long-term monitoring with an implanted device allows for determination of AF pattern, number of discrete episodes and AF burden, providing a wealth of information regarding a patient’s AF.

Recent evidence has suggested the importance of AF burden to cardiovascular and neurological outcomes, and the effect of lifestyle and risk factor modification on AF burden. AF burden is best defined as the proportion of time an individual is in AF during a monitoring period, expressed as a percentage, and continuous monitoring, ideally with an implanted device, is required to meet this definition.

A number of studies have reported improvement in ‘soft’ end points with catheter ablation of AF. However, they are not powered to demonstrate that mortality can be reduced by ablation. The CASTLE-AF trial substantiates these earlier reports that AF ablation is beneficial in patients with AF and HF. The study demonstrated that the use of ablation for AF in patients with HF is associated with a significantly lower composite of death and HF hospitalisation than medical therapy. The results from CASTLE-AF are of significant interest and support a role for AF ablation in such patients. However, these results do not support offering AF ablation to all patients with AF and HF. The inclusion criteria for the trial were strict, resulting in more than 3,000 patients being screened to identify 363 patients to take part in the trial. The quality of the rate control in the pharmacological group has not been published and, in the current review, we have demonstrated the importance of effective rate control in improving LV performance. The mortality benefits of ablation only appeared after 3 years into the trial, by which stage only 191 of the original trial patients were still being followed up. Finally, some subgroups did not benefit from ablation, such as those with an LVEF<25%.67 However, despite these issues, there is sufficient evidence to support early AF ablation in patients with symptomatic AF and HF, in addition to device therapy.

The Future

A significant limitation of all AF ablation studies is the lack of blinding with regard to randomisation and treatment. Randomised, double-blind, placebo-controlled studies are considered the gold standard of studies involving a medical intervention. Randomised clinical trials with inadequate blinding report enhanced placebo effects for intervention groups and nocebo effects for placebo groups.68

It is difficult to perform a truly blinded trial with a sham AF ablation procedure, but the lack of blinding could result in bias as to whether, for example, to admit a patient for worsening HF, how the patients are medically managed, how the patients report symptoms and so on. To date, no studies have included a satisfactory, ethically justifiable sham limb to compare with AF ablation. The advent of such a study design could advance our understanding to another level.

Clinical Perspective

  • The pathophysiological benefits from AF ablation stem from successful restoration and maintenance of sinus rhythm and this is most likely to be achieved by early intervention.
  • These benefits extend to reversed remodelling of the left cardiac chambers, an improvement in left ventricular ejection fraction, an improvement in key, prognostic facets of exercise performance and a reduction in sleep-disordered breathing.
  • Timely treatment of arrhythmia-mediated cardiomyopathy with ablation may minimise irreversible remodelling when sinus rhythm is restored.
  • Given the importance of restoration and maintenance of sinus rhythm following ablation, we propose that AF ablation trials should use stringent heart rhythm monitoring, ideally with implanted devices, allowing monitoring of every heartbeat to document the true impact of ablation on heart rhythm.

References

  1. Cobbe S, ed. Atrial fibrillation in hospital and general practice: the Sir James Mackenzie Consensus Conference. Proc Roy Coll Phys Edinbh 1999;29(3 Suppl 6). http://www.rcpe.ac.uk/journal/supplements/supplement-6.pdf (accessed 22 September 2020).
  2. Verma A, Kalman JM, Callans DJ. Treatment of patients with atrial fibrillation and heart failure with reduced ejection fraction. Circulation 2017;135:1547–63.
    Crossref | PubMed
  3. Mukherjee RK, Williams SE, Niederer SA, et al. Atrial fibrillation ablation in patients with heart failure: one size does not fit all. Arrhythm Electrophysiol Rev 2018;7:84–90.
    Crossref | PubMed
  4. Asad ZUA, Yousif A, Khan MS, et al. Catheter ablation versus medical therapy for atrial fibrillation. Circ Arrhythm Electrophysiol 2019;12:e007414.
    Crossref | PubMed
  5. Moschonas K, Nabeebaccus A, Okonko DO, et al. The impact of catheter ablation for atrial fibrillation in heart failure. J Arrhythm 2019;35:33–42.
    Crossref | PubMed
  6. Kirchhof P, Benussi S, Kotecha D, et al. 2016 ESC guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J 2016;37:2893–962.
    Crossref | PubMed
  7. AFFIRM Investigators. Baseline characteristics of patients with atrial fibrillation: the AFFIRM Study. Am Heart J 2002;143:991–1001.
    Crossref | PubMed
  8. Hagens VE, Van Veldhuisen DJ, Kamp O, et al. Effect of rate and rhythm control on left ventricular function and cardiac dimensions in patients with persistent atrial fibrillation: results from the RAte Control versus Electrical Cardioversion for Persistent Atrial Fibrillation (RACE) study. Heart Rhythm 2005;2:19–24.
    Crossref | PubMed
  9. Cakulev I, Efimov IR, Waldo AL. Cardioversion: past, present, and future. Circulation 2009;120:1623–32.
    Crossref | PubMed
  10. Fazekas T. The concise history of atrial fibrillation. Orvostort Kozl 2007;53:37–68 [in Hungarian].
    PubMed
  11. Kieny JR, Sacrez A, Facello A, et al. Increase in radionuclide left ventricular ejection fraction after cardioversion of chronic atrial fibrillation in idiopathic dilated cardiomyopathy. Eur Heart J 1992;13:1290–5.
    Crossref | PubMed
  12. Glover BM, Walsh SJ, McCann CJ, et al. Biphasic energy selection for transthoracic cardioversion of atrial fibrillation. The BEST AF Trial. Heart 2008;94:884–7.
    Crossref | PubMed
  13. Hellman T, Kiviniemi T, Vasankari T, et al. Prediction of ineffective elective cardioversion of atrial fibrillation: a retrospective multi-center patient cohort study. BMC Cardiovasc Disord 2017;17:33.
    Crossref | PubMed
  14. Boldt LH, Rolf S, Dietz R, Haverkamp W. Atrial fibrillation in patients with heart failure. Pathophysiological concepts and therapeutic options. Dtsch Med Wochenschr 2008;133:2349–54 [in German].
    Crossref | PubMed
  15. Boldt LH, Rolf S, Huemer M, et al. Optimal heart failure therapy and successful cardioversion in heart failure patients with atrial fibrillation. Am Heart J 2008;155:890–5.
    Crossref | PubMed
  16. Calkins H, Hindricks G, Cappato R, et al. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation: executive summary. J Interv Card Electrophysiol 2017;50:1–55.
    Crossref | PubMed
  17. Baher A, Marrouche NF. Treatment of atrial fibrillation in patients with co-existing heart failure and reduced ejection fraction: time to revisit the management guidelines? Arrhythm Electrophysiol Rev 2018;7:91–4.
    Crossref | PubMed
  18. Pedersen OD, Brendorp B, Køber L, et al. Prevalence, prognostic significance, and treatment of atrial fibrillation in congestive heart failure with particular reference to the DIAMOND-CHF study. Congest Heart Fail 2003;9:333–40.
    Crossref | PubMed
  19. Roy D, Talajic M, Nattel S, et al. Rhythm control versus rate control for atrial fibrillation and heart failure. N Engl J Med 2008;358:2667–77.
    PubMed
  20. Dickstein K, Vardas PE, Auricchio A, et al. 2010 focused update of ESC guidelines on device therapy in heart failure: an update of the 2008 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure and the 2007 ESC guidelines for cardiac and resynchronization therapy. Developed with the special contribution of the Heart Failure Association and the European Heart Rhythm Association. Europace 2010;12:1526–36.
    Crossref | PubMed
  21. Steinberg JS. Desperately seeking a randomized clinical trial of resynchronization therapy for patients with heart failure and atrial fibrillation. J Am Coll Cardiol 2006;48:744–6.
    Crossref | PubMed
  22. Molhoek SG, Bax JJ, Bleeker GB, et al. Comparison of response to cardiac resynchronization therapy in patients with sinus rhythm versus chronic atrial fibrillation. Am J Cardiol 2004;94:1506–9.
    Crossref | PubMed
  23. Gasparini M, Auricchio A, Regoli F, et al. Four-year efficacy of cardiac resynchronization therapy on exercise tolerance and disease progression: the importance of performing atrioventricular junction ablation in patients with atrial fibrillation. J Am Coll Cardiol 2006;48:734–43.
    Crossref | PubMed
  24. Dong K, Shen WK, Powell BD, et al. Atrioventricular nodal ablation predicts survival benefit in patients with atrial fibrillation receiving cardiac resynchronization therapy. Heart Rhythm 2010;7:1240–5.
    Crossref | PubMed
  25. Hsu LF, Jaïs P, Sanders P, et al. Catheter ablation for atrial fibrillation in congestive heart failure. N Engl J Med 2004;351:2373–83.
    Crossref | PubMed
  26. Preobrazhenskiı˘ DV. What is the optimal catheter approach for atrial fibrillation in chronic heart failure? Is it rhythm control or rate control? Results of PABA-CHF study. Kardiologiia 2009;49:70–1 [in Russian].
    PubMed
  27. Khan MN, Jaïs P, Cummings J, et al. Pulmonary-vein isolation for atrial fibrillation in patients with heart failure. N Engl J Med 2008;359:1778–85.
    Crossref | PubMed
  28. Corley SD, Epstein AE, DiMarco JP, et al. Relationships between sinus rhythm, treatment, and survival in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study. Circulation 2004;109:1509–13.
    Crossref | PubMed
  29. Liang JJ, Callans DJ. Ablation For atrial fibrillation in heart failure with reduced ejection fraction. Card Fail Rev 2018;4:33–7.
    Crossref | PubMed
  30. Hall TS, von Lueder TG, Zannad F, et al. Relationship between left ventricular ejection fraction and mortality after myocardial infarction complicated by heart failure or left ventricular dysfunction. Int J Cardiol 2018;272:260–6.
    Crossref | PubMed
  31. Veasey RA, Silberbauer J, Schilling RJ, et al. The evaluation of pulmonary vein isolation and wide-area left atrial ablation to treat atrial fibrillation in patients with implanted permanent pacemakers: the Previously Paced Pulmonary Vein Isolation Study. Heart 2010;96:1037–42.
    Crossref | PubMed
  32. Dagres N, Varounis C, Gaspar T, et al. Catheter ablation for atrial fibrillation in patients with left ventricular systolic dysfunction. A systematic review and meta-analysis. J Card Fail 2011;17:964–70.
    Crossref | PubMed
  33. Suman-Horduna I, Roy D, Frasure-Smith N, et al. Quality of life and functional capacity in patients with atrial fibrillation and congestive heart failure. J Am Coll Cardiol 2013;61:455–60.
    Crossref | PubMed
  34. Kuppahally SS, Akoum N, Badger TJ, et al. Echocardiographic left atrial reverse remodeling after catheter ablation of atrial fibrillation is predicted by preablation delayed enhancement of left atrium by magnetic resonance imaging. Am Heart J 2010;160:877–84.
    Crossref | PubMed
  35. Avitall B, Bi J, Mykytsey A, Chicos A. Atrial and ventricular fibrosis induced by atrial fibrillation: evidence to support early rhythm control. Heart Rhythm 2008;5:839–45.
    Crossref | PubMed
  36. Wijesurendra RS, Casadei B. Atrial fibrillation: effects beyond the atrium? Cardiovasc Res 2015;105:238–47.
    Crossref | PubMed
  37. Nattel S, Burstein B, Dobrev D. Atrial remodeling and atrial fibrillation: mechanisms and implications. Circ Arrhythm Electrophysiol 2008;1:62–73.
    Crossref | PubMed
  38. Hanna N, Cardin S, Leung TK, et al. Differences in atrial versus ventricular remodeling in dogs with ventricular tachypacing-induced congestive heart failure. Cardiovasc Res 2004;63:236–44.
    Crossref | PubMed
  39. González A, Schelbert EB, Díez J, et al. Myocardial interstitial fibrosis in heart failure: biological and translational perspectives. J Am Coll Cardiol 2018;71:1696–706.
    Crossref | PubMed
  40. Prabhu S, Costello BT, Taylor AJ, et al. Regression of diffuse ventricular fibrosis following restoration of sinus rhythm with catheter ablation in patients with atrial fibrillation and systolic dysfunction: a substudy of the CAMERA MRI trial. JACC Clin Electrophysiol 2018;4:999–1007.
    Crossref | PubMed
  41. Inoue YY, Alissa A, Khurram IM, et al. Quantitative tissue-tracking cardiac magnetic resonance (CMR) of left atrial deformation and the risk of stroke in patients with atrial fibrillation. J Am Heart Assoc 2015;4:e001844.
    Crossref | PubMed
  42. Parmar BR, Jarrett TR, Kholmovski EG, et al. Poor scar formation after ablation is associated with atrial fibrillation recurrence. J Interv Card Electrophysiol 2015;44:247–56.
    Crossref | PubMed
  43. Nori D, Raff G, Gupta V, et al. Cardiac magnetic resonance imaging assessment of regional and global left atrial function before and after catheter ablation for atrial fibrillation. J Interv Card Electrophysiol 2009;26:109–17.
    Crossref | PubMed
  44. Muellerleile K, Groth M, Steven D, et al. Cardiovascular magnetic resonance demonstrates reversible atrial dysfunction after catheter ablation of persistent atrial fibrillation. J Cardiovasc Electrophysiol 2013;24:762–7.
    Crossref | PubMed
  45. Albouaini K, Egred M, Alahmar A, et al. Cardiopulmonary exercise testing and its application. Postgrad Med J 2007;83:675–82.
    Crossref | PubMed
  46. Fiala M, Wichterle D, Bulková V, et al. A prospective evaluation of haemodynamics, functional status, and quality of life after radiofrequency catheter ablation of long-standing persistent atrial fibrillation. Europace 2014;16:15–25.
    Crossref | PubMed
  47. Jessup M, Abraham WT, Casey DE, et al. 2009 focused update: ACCF/AHA guidelines for the diagnosis and management of heart failure in adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation. Circulation. 2009;119:1977–2016.
    Crossref | PubMed
  48. Mancini DM, Eisen H, Kussmaul W, et al. Value of peak exercise oxygen consumption for optimal timing of cardiac transplantation in ambulatory patients with heart failure. Circulation 1991;83:778–86.
    Crossref | PubMed
  49. Swank AM, Horton J, Fleg JL, et al. Modest increase in peak VO2 is related to better clinical outcomes in chronic heart failure patients: results from heart failure and a controlled trial to investigate outcomes of exercise training. Circ Heart Fail 2012;5:579–85.
    Crossref | PubMed
  50. Kwon Y, Misialek JR, Duprez D, et al. Association between sleep disordered breathing and electrocardiographic markers of atrial abnormalities: the MESA study. Europace 2017;19:1759–66.
    Crossref | PubMed
  51. Morrell MJ, McMillan A. Does age matter? The relationship between sleep-disordered breathing and incident atrial fibrillation in older men. Am J Respir Crit Care Med 2016;193:712–4.
    Crossref | PubMed
  52. Fox H, Bitter T, Horstkotte D, et al. Cardioversion of atrial fibrillation or atrial flutter into sinus rhythm reduces nocturnal central respiratory events and unmasks obstructive sleep apnoea. Clin Res Cardiol 2016;105:451–9.
    Crossref | PubMed
  53. Sanders P, Elliott AD, Linz D. Upstream targets to treat atrial fibrillation. J Am Coll Cardiol 2017;70:2906–8.
    Crossref | PubMed
  54. Pathak RK, Evans M, Middeldorp ME, et al. Cost-effectiveness and clinical effectiveness of the risk factor management clinic in atrial fibrillation: the CENT study. JACC Clin Electrophysiol 2017;3:436–47.
    Crossref | PubMed
  55. Naruse Y, Tada H, Satoh M, et al. Radiofrequency catheter ablation of persistent atrial fibrillation decreases a sleep-disordered breathing parameter during a short follow-up period. Circ J 2012;76:2096–103.
    Crossref | PubMed
  56. O’Brien LM, Bullough AS, Shelgikar AV, et al. Validation of Watch-PAT-200 against polysomnography during pregnancy. J Clin Sleep Med 2012;8:287–94.
    Crossref | PubMed
  57. Iwasaki YK, Shi Y, Benito B, et al. Determinants of atrial fibrillation in an animal model of obesity and acute obstructive sleep apnea. Heart Rhythm 2012;9:1409–16.e1.
    Crossref | PubMed
  58. Marulanda-Londoño E, Chaturvedi S. The interplay between obstructive sleep apnea and atrial fibrillation. Front Neurol 2017;8:668.
    Crossref | PubMed
  59. Redolfi S, Yumino D, Ruttanaumpawan P, et al. Relationship between overnight rostral fluid shift and obstructive sleep apnea in nonobese men. Am J Respir Crit Care Med 2009;179:241–6.
    Crossref | PubMed
  60. Bucca CB, Brussino L, Battisti A, et al. Diuretics in obstructive sleep apnea with diastolic heart failure. Chest 2007;132:440–6.
    Crossref | PubMed
  61. Tang SC, Lam B, Lai AS, et al. Improvement in sleep apnea during nocturnal peritoneal dialysis is associated with reduced airway congestion and better uremic clearance. Clin J Am Soc Nephrol 2009;4:410–8.
    Crossref | PubMed
  62. Lavie P, Lavie L, Herer P. All-cause mortality in males with sleep apnoea syndrome: declining mortality rates with age. Eur Respir J 2005;25:514–20.
    Crossref | PubMed
  63. Marrouche NF, Kheirkhahan M, Brachmann J. Catheter ablation for atrial fibrillation with heart failure. N Engl J Med 2018;379:492.
    Crossref | PubMed
  64. Terricabras M, Verma A, Morillo CA. Measuring success in ablation of atrial fibrillation: time for a paradigm shift? Circ Arrhythm Electrophysiol 2018;11:e006582.
    Crossref | PubMed
  65. Podd SJ, Sugihara C, Furniss SS, et al. Are implantable cardiac monitors the ‘gold standard’ for atrial fibrillation detection? A prospective randomized trial comparing atrial fibrillation monitoring using implantable cardiac monitors and DDDRP permanent pacemakers in post atrial fibrillation ablation patients. Europace 2016;18:1000–5.
    Crossref | PubMed
  66. Tondo C, Iacopino S, Pieragnoli P, et al. Pulmonary vein isolation cryoablation for patients with persistent and long-standing persistent atrial fibrillation: clinical outcomes from the real-world multicenter observational project. Heart Rhythm 2018;15:363–8.
    Crossref | PubMed
  67. Bono J, Kirchhof P. Is there a CASTLE-AF on the hill? Eur Heart J 2018;39(16):1324–5.
    Crossref | PubMed
  68. Kaptchuk TJ. The double-blind, randomized, placebo-controlled trial: gold standard or golden calf? J Clin Epidemiol 2001;54:
    541–9.
    Crossref | PubMed
  69. MacDonald MR, Connelly DT, Hawkins NM, et al. Radiofrequency ablation for persistent atrial fibrillation in patients with advanced heart failure and severe left ventricular systolic dysfunction: a randomised controlled trial. Heart 2011;97:740–7.
    Crossref | PubMed
  70. Jones DG, Haldar SK, Jarman JW, et al. Impact of stepwise ablation on the biatrial substrate in patients with persistent atrial fibrillation and heart failure. Circ Arrhythm Electrophysiol 2013;6:761–8.
    Crossref | PubMed
  71. Hunter RJ, Berriman TJ, Diab I, et al. A randomized controlled trial of catheter ablation versus medical treatment of atrial fibrillation in heart failure (the CAMTAF trial). Circ Arrhythm Electrophysiol 2014;7:31–8.
    Crossref | PubMed
  72. Di Biase L, Mohanty P, Mohanty S, et al. Ablation versus amiodarone for treatment of persistent atrial fibrillation in patients with congestive heart failure and an implanted device: results from the AATAC multicenter randomized trial. Circulation 2016;133:1637–44.
    Crossref | PubMed
Previous Volume Article Next Volume Article