Impact of anti-arrhythmic drugs and catheter ablation on the survival of patients with atrial fibrillation: a population study based on 199 433 new-onset atrial fibrillation patients in the UK

Contemporary Study of New Onset Atrial Fibrillation Treatment Strategies at a Large Academic Tertiary Care Center

BACKGROUND

Early rhythm-control after atrial fibrillation (AF) incidence is associated with improved cardiovascular outcomes. Moreover, AF ablation provides more effective rhythm-control than antiarrhythmic drugs (AADs). The extent of adoption of contemporary trials and guidelines for the management of new onset AF is unknown.

OBJECTIVE

In this observational retrospective study, we sought to evaluate treatment pathways for new onset AF at a large tertiary academic medical center within the last 6 years.

METHODS

We performed a systematic search within our institutional TriNetX database to identify adult patients who (1) had new onset AF between January 2018 and January 2023, (2) did not have surgery or thyrotoxicosis within 1 month of incident AF diagnosis, and (3) had at least one visit at our center > 6 months after initial AF diagnosis. Patients with prior AF diagnosis were excluded. We identified the initial three lines of treatment administered following AF diagnosis, including rate- or rhythm-control strategies with AADs or ablation therapy.

RESULTS

The cohort included 24 990 patients (mean age at diagnosis 69.8 ± 13.1 years, 58% male). During follow-up, 7130 (29%) received rhythm-control, 9760 (39%) received rate-control, and 8100 (32%) received neither. Rhythm-control consisted of AADs in 4610 (18%) and AF ablation in 2530 (10%). As first line therapy, 12 055 (48%) patients received rate-control, 3919 (16%) received AADs and 916 (4%) underwent AF ablation.

CONCLUSION

Most contemporary patients with incident AF at a large US academic tertiary center either received no rate or rhythm intervention or only rate-control.

Evolution in electrophysiology 100 years after Einthoven: translational and computational innovations in rhythm control of atrial fibrillation

In 1924, the Dutch physiologist Willem Einthoven received the Nobel Prize in Physiology or Medicine for his discovery of the mechanism of the electrocardiogram (ECG). Anno 2024, the ECG is commonly used as a diagnostic tool in cardiology. In the paper 'Le Télécardiogramme', Einthoven described the first recording of the now most common cardiac arrhythmia: atrial fibrillation (AF). The treatment of AF includes rhythm control, aiming to alleviate symptoms and improve quality of life. Recent studies found that early rhythm control might additionally improve clinical outcomes. However, current therapeutic options have suboptimal efficacy and safety, highlighting a need for better rhythm-control strategies. In this review, we address the challenges related to antiarrhythmic drugs (AADs) and catheter ablation for rhythm control of AF, including significant recurrence rates and adverse side effects such as pro-arrhythmia. Furthermore, we discuss potential solutions to these challenges including novel tools, such as atrial-specific AADs and digital-twin-guided AF ablation. In particular, digital twins are a promising method to integrate a wide range of clinical data to address the heterogeneity in AF mechanisms. This may enable a more mechanism-based tailored approach that may overcome the limitations of previous precision medicine approaches based on individual biomarkers. However, several translational challenges need to be addressed before digital twins can be routinely applied in clinical practice, which we discuss at the end of this narrative review. Ultimately, the significant advances in the detection, understanding, and treatment of AF since its first ECG documentation are expected to help reduce the burden of this troublesome condition.

[Update atrial fibrillation in older adults]

Atrial fibrillation is the most frequent cardiac arrhythmia in old age. As a result of the positive data on ablation, the focus has shifted to rhythm control. Older adults can also benefit from catheter ablation. Oral anticoagulation remains an essential part of the pharmacological treatment of atrial fibrillation. Recent study results show that geriatric patients require an individual treatment approach, which should be based on the recommendations of the current guidelines and the use of supplementary aids. The assessment of functionality should be taken into account in the treatment and the treatment goal planning as well as symptoms associated with atrial fibrillation. In acute situations cardioversion and long-term drug or interventional (catheter ablation) rhythm-stabilizing treatment are available for rhythm control.

Early rhythm control in atrial fibrillation anno 2024

Atrial fibrillation is a chronic progressive disease and is the most common arrhythmia in adults. It is a major cause of cardiovascular morbidity and mortality. The EAST-AFNET 4 trial demonstrated that rhythm control in patients with early atrial fibrillation significantly reduces cardiovascular outcomes compared to usual care. The effectiveness of early rhythm control is predominantly mediated by the presence of sinus rhythm and early rhythm control is more effective in patients with multiple comorbidities. Studies such as STOP-AF First, Cryo-FIRST, EARLY-AF and its 3-year follow-up trial demonstrate that first-line catheter ablation is more effective in maintaining sinus rhythm than anti-arrhythmic drug therapy. These findings are leading to a paradigm shift in the electrophysiology community in favour of early rhythm control with catheter ablation when feasible.

Effects of antiarrhythmic drug responsiveness and diagnosis-to-ablation time on outcomes after catheter ablation for persistent atrial fibrillation

Background

The impact of delaying atrial fibrillation catheter ablation (AFCA) for antiarrhythmic drug (AAD) management on the disease course remains unclear. This study investigated AFCA rhythm outcomes based on the diagnosis-to-ablation time (DAT) and AAD responsiveness in participants with persistent AF (PeAF).

Methods

We included data from 1038 AAD-resistant PeAF participants, all of whom had a clear time point for AF diagnosis, especially PeAF at diagnosis time, and had undergone an AFCA for the first time. Participants who experienced recurrences of paroxysmal type on AAD therapy were analyzed as a cohort of AAD-partial responders; those maintaining PeAF on AAD were AAD-non-responders. We determined the DAT cutoff for best discriminating long-term rhythm outcomes using a maximum log-likelihood estimation method based on the Cox proportional hazard regression model.

Results

Of the participants (79.8% male; median age 61), 806 (77.6%) were AAD-non-responders. AAD-non-responders had a higher body mass index and a larger left atrial diameter than AAD-partial-responders. They also had a higher incidence of AF recurrence after AFCA (adjusted hazard ratio 1.75, 95% confidence interval 1.33-2.30; log-rank p < .001) compared to AAD-partial-responders. The maximum log-likelihood estimation showed bimodal cutoffs at 22 and 40 months. The optimal DAT cutoff rhythm outcome was 22 months, which discriminated better in the AAD-partial-responders than in the AAD-non-responders.

Conclusions

Both DAT and AAD responsiveness influenced AFCA rhythm outcomes. Delaying AFCA to a DAT of longer than 22 months was inadvisable, particularly in the participants in whom PeAF was changed to paroxysmal AF during AAD therapy.

Effect of early catheter ablation of atrial fibrillation in patients with heart failure

INTRODUCTION

According to current guidelines, pulmonary vein isolation as first-line therapy should be considered for patients with atrial fibrillation (AF), however, optimal timing of the procedure is still unknown in patients with heart failure (HF). We aimed to evaluate the effect of early catheter ablation (CA) in patients with HF and left ventricular ejection fraction (LVEF) below 50%.

METHODS

We analyzed data from a structured registry comprising 227 patients with paroxysmal or persistent AF and HF with LVEF < 50% who underwent radiofrequency CA between 2015 and 2022. Early CA was defined as a procedure performed within 12 months of AF diagnosis. The median follow-up duration was 1748 (1176.3-2353.5) days, with a minimum follow-up of 365 days. Our endpoints were AF recurrence after a 3-months blanking period and all-cause mortality.

RESULTS

Among the 227 patients with a median age of 64.3 years, 97 (42.7%) experienced AF recurrence and 55 (24.2%) died during the follow-up period. The median LVEF was 40% for early CA and 38% for delayed CA (p = .053). Early CA significantly reduced AF recurrence (HR = 0.25 [0.15-0.42], p < .001), however, the timing of procedure did not affect all-cause mortality (p = .16). These findings were consistent regardless of AF subtype or the burden of comorbidities, as assessed by the CHA2DS2-VASc score.

CONCLUSION

The timing of CA of AF appears to be an important factor in patients with HF. Early CA reduced AF recurrence, although it does not impact all-cause mortality. We found similar results regardless of AF subtype or burden of comorbidities.

[Type 2 amiodarone-induced thyrotoxicosis: prevalence, time and predictors of development]

BACKGROUND

Amiodarone takes a leading position in arrhythmological practice in the prevention and relief of various cardiac arrhythmias. Type 2 amiodarone-induced thyrotoxicosis is a frequent side effect of the drug. It is the most complex type of thyroid dysfunction both in terms of the severity of clinical manifestations, and in terms of understanding the mechanisms of pathogenesis, possibility of differential diagnosis and providing effective treatment. Due to the increasing life expectancy of the population, corresponding increase in the frequency of cardiac arrhythmias, the problem does not lose its relevance. Identification of predictors, assessment and prediction of the individual risk of developing this thyroid pathology is a necessity in daily clinical practice for making a reasonable decision when prescribing the drug, determining the algorithm for further dynamic monitoring of the patient.

AIM

To evaluate the structure of amiodarone-induced thyroid dysfunction, prevalence, time and predictors of development type 2 amiodarone-induced thyrotoxicosis in a prospective cohort study. MATERIALS AND METHODS: The study involved 124 patients without thyroid dysfunction who received amiodarone therapy for the first time. Evaluation of the functional state of the thyroid gland was performed initially, after prescribing the drug for the first 3 months 1 time per month, in the future - every 3 months. The follow-up period averaged 12-24 months. The end of the observation occurred with the development of amiodaron-induced thyroid dysfunction or patient's refusal to further participate in the study. For the differential diagnosis of the type of amiodarone-induced thyrotoxicosis, the level of anti-TSH receptor antibodies and thyroid scintigraphy with technetium pertechnetate were determined. The type and frequency of thyroid dysfunction, time and predictors of development type 2 amiodarone-induced thyrotoxicosis were evaluated.

RESULTS

The structure of amiodarone-induced thyroid dysfunction was represented by hypothyroidism in 19,3% (n=24), type 1 thyrotoxicosis in 1,6% (n=2), type 2 thyrotoxicosis in 23,4% (n=29). The median time of its development was 92,0 [69,0;116,0] weeks; the average period of common survival - 150,2±12,6 weeks (95% CI: 125,5-175,0), median - 144±21,7 weeks (95% CI: 101,4-186,6). The main predictors of type 2 amiodarone-induced thyrotoxicosis were: age (OR=0,931; 95% CI: 0,895-0,968; p<0.001), BMI (OR=0,859; 95% CI: 0,762-0,967; p=0,012), time from the start of amiodarone therapy (OR=1,023; 95% CI: 1,008-1,038; p=0,003). Age ≤60 years was associated with increased risk of the dysfunction by 2.4 times (OR=2,352; 95% CI: 1,053-5,253; p=0,037), BMI≤26,6 kg/m2 - 2,3 times (OR=2,301; 95% CI: 1,025-5,165; p=0,043). CONCLUSION: The results allow to personalized estimate the risk of type 2 amiodarone-induced thyrotoxicosis and determine the patient's management tactic.

Electronic health record-wide association study for atrial fibrillation in a British cohort

Background

Atrial fibrillation (AF) confers a major healthcare burden from hospitalisations and AF-related complications, such as stroke and heart failure. We performed an electronic health records-wide association study to identify the most frequent reasons for healthcare utilization, pre and post new-onset AF.

Methods

Prospective cohort study with the linked electronic health records of 5.6 million patients in the United Kingdom Clinical Practice Research Datalink (1998-2016). A cohort study with AF patients and their age-and sex matched controls was implemented to compare the top 100 reasons of frequent hospitalisation and primary consultation.

Results

Of the 199,433 patients who developed AF, we found the most frequent healthcare interactions to be cardiac, cerebrovascular and peripheral-vascular conditions, both prior to AF diagnosis (41/100 conditions in secondary care, such as cerebral infarction and valve diseases; and 33/100 conditions in primary care), and subsequently (47/100 conditions hospital care and 48 conditions in primary care). There was a high representation of repeated visits for cancer and infection affecting multiple organ systems. We identified 10 novel conditions which have not yet been associated with AF: folic acid deficiency, pancytopenia, idiopathic thrombocytopenic purpura, seborrheic dermatitis, lymphoedema, angioedema, laryngopharyngeal reflux, rib fracture, haemorrhagic gastritis, inflammatory polyneuropathies.

Conclusion

Our nationwide data provide knowledge and better understanding of the clinical needs of AF patients suggesting: (i) groups at higher risk of AF, where screening may be more cost-effective, and (ii) potential complications developing following new-onset AF that can be prevented through implementation of comprehensive integrated care management and more personalised, tailored treatment.

Clinical trial registration

NCT04786366.

Managing arrhythmia in cardiac resynchronisation therapy

Arrhythmia is an extremely common finding in patients receiving cardiac resynchronisation therapy (CRT). Despite this, in the majority of randomised trials testing CRT efficacy, patients with a recent history of arrhythmia were excluded. Most of our knowledge into the management of arrhythmia in CRT is therefore based on arrhythmia trials in the heart failure (HF) population, rather than from trials dedicated to the CRT population. However, unique to CRT patients is the aim to reach as close to 100% biventricular pacing (BVP) as possible, with HF outcomes greatly influenced by relatively small changes in pacing percentage. Thus, in comparison to the average HF patient, there is an even greater incentive for controlling arrhythmia, to achieve minimal interference with the effective delivery of BVP. In this review, we examine both atrial and ventricular arrhythmias, addressing their impact on CRT, and discuss the available evidence regarding optimal arrhythmia management in this patient group. We review pharmacological and procedural-based approaches, and lastly explore novel ways of harnessing device data to guide treatment of arrhythmia in CRT.