Atrial fibrillation ablation in practice: assessing CABANA generalizability

Novel stroke prevention strategies following catheter ablation for atrial fibrillation

Stroke prevention following successful catheter ablation of atrial fibrillation remains a controversial topic. Oral anticoagulation is associated with a significant reduction in stroke risk in the general atrial fibrillation population but may be associated with an increased risk of major bleeding, and the benefit: risk ratio must be considered. Improvement in successful catheter ablation and widespread use of cardiac monitoring devices may allow for novel anticoagulation strategies in a subset of patients with atrial fibrillation, which may optimize stroke prevention while minimizing bleeding risk. In this review, we discuss stroke risk in atrial fibrillation and the effects of successful catheter ablation on thromboembolic risk. We also explore novel strategies for stroke prevention following successful catheter ablation.

Ten-Year Trend of Oral Anticoagulation Use in Postoperative and Nonpostoperative Atrial Fibrillation in Routine Clinical Practice

BACKGROUND

The study aimed to describe the patterns and trends of initiation, discontinuation, and adherence of oral anticoagulation (OAC) in patients with new-onset postoperative atrial fibrillation (POAF), and compare with patients newly diagnosed with non-POAF.

METHODS AND RESULTS

This retrospective cohort study identified patients newly diagnosed with atrial fibrillation or flutter between 2012 and 2021 using administrative claims data from OptumLabs Data Warehouse. The POAF cohort included 118 366 patients newly diagnosed with atrial fibrillation or flutter within 30 days after surgery. The non-POAF cohort included the remaining 315 832 patients who were newly diagnosed with atrial fibrillation or flutter but not within 30 days after a surgery. OAC initiation increased from 28.9% to 44.0% from 2012 to 2021 in POAF, and 37.8% to 59.9% in non-POAF; 12-month medication adherence increased from 47.0% to 61.8% in POAF, and 59.7% to 70.4% in non-POAF. The median time to OAC discontinuation was 177 days for POAF, and 242 days for non-POAF. Patients who saw a cardiologist within 90 days of the first atrial fibrillation or flutter diagnosis, regardless of POAF or non-POAF, were more likely to initiate OAC (odds ratio, 2.92 [95% CI, 2.87-2.98]; P <0.0001), adhere to OAC (odds ratio, 1.08 [95% CI, 1.04-1.13]; P <0.0001), and less likely to discontinue (odds ratio, 0.83 [95% CI, 0.82-0.85]; P <0.0001) than patients who saw a surgeon or other specialties.

CONCLUSIONS

The use of and adherence to OAC were higher in non-POAF patients than in POAF patients, but they increased over time in both groups. Patients managed by cardiologists were more likely to use and adhere to OAC, regardless of POAF or non-POAF.

[Acute heart failure with altered ejection fraction : Electrocardiographic signs with mortality at the Abidjan cardiology institute]

INTRODUCTION

Heart failure with impaired ejection fraction (HFIEF) represents the end-stage of most cardiac diseases, and is responsible for a high mortality rate. In order to identify patients at risk, numerous clinical and paraclinical prognostic factors have been proposed. The electrocardiogram (ECG), easy to perform and inexpensive, retains a powerful role in the prognostic evaluation of heart failure patients. The aim was to evaluate ECG signs associated with mortality in a retrospective cohort of patients with ICFEA.

METHODOLOGY

The study was observational and analytical based on retrospective data collected from patients benefiting from a primary hospitalization for ICFEA at the Abidjan Heart Institute from January 2018 to July 2020.

RESULTS

Of the 370 patients included, 197 had died by August 1, 2020, representing an overall mortality of 53%. Mortality progressed gradually up to one year, then remained unchanged up to 30 months. In multivariate Cox regression including ECG variables only, the presence of intra-ventricular conduction disorders (OR: 1.80; 95% CI [1.01-3.25]), microvoltage (OR: 1.82; 95% CI [1.05-16]), and pathological Q waves (OR: 1.70; 95% CI [1.02-2.83]), were significantly associated with overall mortality. When ECG variables and clinical, paraclinical and therapeutic demographic variables were included, only the presence of pathological Q waves (OR:1.74; 95% CI [1.01-3.01]) persisted as a risk factor for mortality. Hypertension and treatment of heart failure, in particular ACEI/ARII, beta-blockers and ARM, were protective factors. The presence of Q waves was associated with a significant reduction in survival, based on curves obtained using the Kaplan-Meier model.

CONCLUSION

ICFEA is responsible for high mortality, mainly in the year following the 1st hospitalization for cardiac decompensation. The presence of pathological Q waves is the only electrocardiographic sign that remains statistically associated with a poor prognosis, after adjustment.

Atrial fibrillation: comorbidities, lifestyle, and patient factors

Modern anticoagulation therapy has dramatically reduced the risk of stroke and systemic thromboembolism in people with atrial fibrillation (AF). However, AF still impairs quality of life, increases the risk of stroke and heart failure, and is linked to cognitive impairment. There is also a recognition of the residual risk of thromboembolic complications despite anticoagulation. Hence, AF management is evolving towards a more comprehensive understanding of risk factors predisposing to the development of this arrhythmia, its' complications and interventions to mitigate the risk. This review summarises the recent advances in understanding of risk factors for incident AF and managing these risk factors. It includes a discussion of lifestyle, somatic, psychological, and socioeconomic risk factors. The available data call for a practice shift towards a more individualised approach considering an increasingly broader range of health and patient factors contributing to AF-related health burden. The review highlights the needs of people living with co-morbidities (especially with multimorbidity), polypharmacy and the role of the changing population demographics affecting the European region and globally.

Association between catheter ablation of atrial fibrillation and mortality or stroke

OBJECTIVE

Catheter ablation of atrial fibrillation effectively reduces symptomatic burden. However, its long-term effect on mortality and stroke is unclear. We investigated if patients with atrial fibrillation who undergo catheter ablation have lower risk for all-cause mortality or stroke than patients who are managed medically.

METHODS

We retrospectively included 5628 consecutive patients who underwent first-time catheter ablation for atrial fibrillation between 2008 and 2018 at three major Swedish electrophysiology units. Control individuals with an atrial fibrillation diagnosis but without previous stroke were selected from the Swedish National Patient Register, resulting in a control group of 48 676 patients. Propensity score matching was performed to produce two cohorts of equal size (n=3955) with similar baseline characteristics. The primary endpoint was a composite of all-cause mortality or stroke.

RESULTS

Patients who underwent catheter ablation were healthier (mean CHA2DS2-VASc score 1.4±1.4 vs 1.6±1.5, p<0.001), had a higher median income (288 vs 212 1000 Swedish krona [KSEK]/year, p<0.001) and had more frequently received university education (45.1% vs 28.9%, p<0.001). Mean follow-up was 4.5±2.8 years. After propensity score matching, catheter ablation was associated with lower risk for the combined primary endpoint (HR 0.58, 95% CI 0.48 to 0.69). The result was mainly driven by a decrease in all-cause mortality (HR 0.51, 95% CI 0.41 to 0.63), with stroke reduction showing a trend in favour of catheter ablation (HR 0.75, 95% CI 0.53 to 1.07).

CONCLUSIONS

Catheter ablation of atrial fibrillation was associated with a reduction in the primary endpoint of all-cause mortality or stroke. This result was driven by a marked reduction in all-cause mortality.

Interventional Management of Atrial Fibrillation in the Chronic Heart Failure Population

Atrial fibrillation (AF) and heart failure (HF) synergistically interact to exacerbate each other. However, treatment of one entity can greatly improve management of the other. Although historically, permissive medical therapy was the mainstay of AF management in the HF population, recent data strongly favor early, often invasive, intervention for AF to reduce hard HF outcomes. It seems that intervening earlier in the time course of AF, though still not excluding persistent AF from treatment, may have more pronounced effects.

Catheter ablation versus medical therapy for atrial fibrillation with prior stroke history: a prospective propensity score-matched cohort study

BACKGROUND

Patients with atrial fibrillation (AF) and prior stroke history have a high risk of cardiovascular events despite anticoagulation therapy. It is unclear whether catheter ablation (CA) has further benefits in these patients.

METHODS

AF patients with a previous history of stroke or systemic embolism (SE) from the prospective Chinese Atrial Fibrillation Registry study between August 2011 and December 2020 were included in the analysis. Patients were matched in a 1:1 ratio to CA or medical treatment (MT) based on propensity score. The primary outcome was a composite of all-cause death or ischemic stroke (IS)/SE.

RESULTS

During a total of 4.1 ± 2.3 years of follow-up, the primary outcome occurred in 111 patients in the CA group (3.3 per 100 person-years) and in 229 patients in the MT group (5.7 per 100 person-years). The CA group had a lower risk of the primary outcome compared to the MT group [hazard ratio (HR) = 0.59, 95% CI: 0.47-0.74, P < 0.001]. There was a significant decreasing risk of all-cause mortality (HR = 0.43, 95% CI: 0.31-0.61, P < 0.001), IS/SE (HR = 0.73, 95% CI: 0.54-0.97, P = 0.033), cardiovascular mortality (HR = 0.32, 95% CI: 0.19-0.54, P < 0.001) and AF recurrence (HR = 0.33, 95% CI: 0.30-0.37, P < 0.001) in the CA group compared to that in the MT group. Sensitivity analysis generated consistent results when adjusting for time-dependent usage of anticoagulants.

CONCLUSIONS

In AF patients with a prior stroke history, CA was associated with a lower combined risk of all-cause death or IS/SE. Further clinical trials are warranted to confirm the benefits of CA in these patients.

The impact of age on ablation outcomes in AF-mediated cardiomyopathy

INTRODUCTION

The absence of ventricular scar in patients with atrial fibrillation (AF) and systolic heart failure (HF) predicts left ventricular (LV) recovery following AF ablation. It is unknown whether age impacts the degree of LV recovery, reverse remodeling, or AF recurrence following catheter ablation (CA) among this population.

OBJECTIVES

To evaluate the impact of age on LV recovery and AF recurrence in a population with AF and systolic HF without fibrosis (termed AF-mediated cardiomyopathy) following CA.

METHODS

Consecutive patients undergoing CA between 2013 and 2021 with LV ejection fraction (LVEF) < 45% and absence of cardiac magnetic resonance imaging (CMR) detected LV myocardial fibrosis were stratified by age (<65 vs. ≥65 years). Following CA, participants underwent remote rhythm monitoring for 12 months with repeat CMR for HF surveillance.

RESULTS

The study population consisted of 70 patients (10% female, mean LVEF 33 ± 9%), stratified into younger (age < 65 years, 63%) and older (age ≥ 65 years, 37%) cohorts. Baseline comorbidities, LVEF (34 ± 9 vs. 33 ± 8 ≥65 years, p = .686), atrial and ventricular dimensions (left atrial volume index: 55 ± 21 vs. 56 ± 14 mL/m2 age ≥ 65, p = .834; indexed left ventricular end-diastolic volume: 108 ± 40 vs. 104 ± 28 mL/m2 age ≥ 65, p = .681), pharmacotherapy and ablation strategy (pulmonary vein isolation in all; posterior wall isolation in 27% vs. 19% age ≥ 65, p = .448; cavotricuspid isthmus in 9% vs. 11.5% age ≥ 65) were comparable (all p > .05) albeit a higher CHADS2 VASc score in the older cohort (2.7 ± 0.9 vs. 1.6 ± 0.6 age < 65, p < .001).   Freedom from AF was comparable (hazard ratio: 0.65, 95% confidence interval: 0.38-1.48, LogRank p = .283) as was AF burden [0% (interquartile range, IQR: 0.0-2.1) vs. age ≥ 65: [0% (IQR 0.0-1.7), p = .516], irrespective of age. There was a significant improvement in LV systolic function in both groups (ΔLVEF + 21 ± 14% vs. +21 ± 12% age ≥ 65, p = .913), with LV recovery in the vast majority (73% vs. 69%, respectively, p = .759) at 13 (IQR: 12-16) months. This was accompanied by comparable improvements in functional status (New York Heart Association class p = .851; 6-min walk distance 50 ± 61 vs. 93 ± 134 m in age ≥ 65, p = .066), biomarkers (ΔN-terminal-pro brain natriuretic peptide -139 ± 246 vs. -168 ± 181 age ≥ 65,p = .629) and HF symptoms (Short Form-36 survey Δphysical component summary p = .483/Δmental component summary, p = .841).

CONCLUSION

In patients undergoing CA for AF with systolic HF in the absence of ventricular scar, comparable improvements in ventricular function, symptoms, and freedom from AF are achieved irrespective of age.

The Effectiveness of Ablation Therapy for Atrial Fibrillation: A Systematic Review

It is expected that the prevalence of atrial fibrillation (AF), the most prevalent cardiac arrhythmia among people aged 65 to 85, would be mostly classified using the CHAS2DS2-VASc approach for anticoagulation therapy. A high number of people in the entire world will be living with AF by 2030. Long-term follow-up data are sparse, although radiofrequency catheter ablation (CA) for symptomatic AF patients has the potential to be a curative therapy. Although women are referred later and less often than men, the outcomes following ablation are comparable across both genders. Health-related quality of life suffers from AF, and patients often find themselves less active as a result of their condition. AF may have a wide variety of symptoms and signs from the clinic's point of view. Women are more likely to exhibit symptoms than men; one reason for this is that women have an average QT interval that is 10-20 milliseconds longer than men, which is more likely to exacerbate tachycardia symptoms. In search of medical databases for relevant medical literature, we looked at PubMed/Medline, the Cochrane Library, and Google Scholar. Ten publications were gathered after the papers were located, assessed, and qualifying criteria applied were used to select them. The finished articles were done to give an overview of the effectiveness of ablation therapy for AF. Some studies showed that there was no statistical significance between invasive and pharmacological treatments. Other research found no difference in the recurrence of atrial arrhythmia between pulmonary vein isolation (PVI) CA alone and PVI + enhancement magnetic resonance imaging (MRI)-guided fibrosis ablation in individuals with persistent AF. The oldest individuals in studies comparing CA to medical treatment for AF demonstrated no improvement in prognosis after CA. Also, complications from therapy and CA's efficacy in preventing future atrial arrhythmias were similarly low across all age groups. Based on the above, we concluded that more studies are required to establish the most effective approach to treating AF to apply it in daily practice and gain more knowledge about it.

The effect of treatment strategy on long-term follow-up results in patients with nonvalvular atrial fibrillation in Turkey: AFTER-2 subgroup analysis

BACKGROUND

We performed a subanalysis of the data from the AFTER-2 registry. In our study, we aimed to compare the long-term follow-up results of nonvalvular atrial fibrillation (NVAF) patients in Turkey according to their treatment strategies.

METHODS

All consecutive patients older than 18 years of age who presented to cardiology outpatient clinics, had at least one AF attack and did not have rheumatic mitral valve stenosis or prosthetic heart valve disease were included in our prospective study. The patients were divided into two groups as rhythm control and rate control. Stroke, hospitalization and death rates were compared between the groups.

RESULTS

A total of 2592 patients from 35 centers were included in the study. Of these patients, 628 (24.2%) were in the rhythm control group and 1964 (75.8%) in the rate control group. New-onset ischemic cerebrovascular disease or transient ischemic attack (CVD/TIA) was detected at a lower rate in the rhythm control group (3.2% vs. 6.2% p = 0.004). However, there was no significant difference in one-year and five-year mortality rates (9.6% versus 9.0%, p = 0.682 and 31.8% versus 28.6%, p = 0.116, respectively). Hospitalization were found to be significantly higher in patients with rhythm control group (18% vs. 13%, p = 0.002).

CONCLUSION

It was found that rhythm control strategy is preferred in AF patients in Turkey. We found a lower rate of ischemic CVD/TIA in patients in the rhythm control group. Although no difference was observed in mortality rates, we found a higher rate of hospitalization in the rhythm control group.

Outcomes of Early Rhythm Control Therapy in Patients With Atrial Fibrillation and a High Comorbidity Burden in Large Real-World Cohorts

BACKGROUND

A recent subanalysis of the EAST-AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial) suggests a stronger benefit of early rhythm control (ERC) in patients with atrial fibrillation and a high comorbidity burden when compared to patients with a lower comorbidity burden.

METHODS

We identified 109 739 patients with newly diagnosed atrial fibrillation in a large United States deidentified administrative claims database (OptumLabs) and 11 625 patients in the population-based UKB (UK Biobank). ERC was defined as atrial fibrillation ablation or antiarrhythmic drug therapy within the first year after atrial fibrillation diagnosis. Patients were classified as (1) ERC and high comorbidity burden (CHA2DS2-VASc score ≥4); (2) ERC and lower comorbidity burden (CHA2DS2-VASc score 2-3); (3) no ERC and high comorbidity burden; and (4) no ERC and lower comorbidity burden. Patients without an elevated comorbidity burden (CHA2DS2-VASc score 0-1) were excluded. Propensity score overlap weighting and cox proportional hazards regression were used to balance patients and compare groups for the primary composite outcome of all-cause mortality, stroke, or hospitalization with the diagnoses heart failure or myocardial infarction as well as for a primary composite safety outcome of death, stroke, and serious adverse events related to ERC.

RESULTS

In both cohorts, ERC was associated with a reduced risk for the primary composite outcome in patients with a high comorbidity burden (OptumLabs: hazard ratio, 0.83 [95% CI 0.72-0.95]; P=0.006; UKB: hazard ratio, 0.77 [95% CI, 0.63-0.94]; P=0.009). In patients with a lower comorbidity burden, the difference in outcomes was not significant (OptumLabs: hazard ratio, 0.92 [95% CI, 0.54-1.57]; P=0.767; UKB: hazard ratio, 0.94 [95% CI, 0.83-1.06]; P=0.310). The comorbidity burden interacted with ERC in the UKB (interaction- P=0.027) but not in OptumLabs (interaction-P=0.720). ERC was not associated with an increased risk for the primary safety outcome.

CONCLUSIONS

ERC is safe and may be more favorable in a population-based sample of patients with high a comorbidity burden (CHA2DS2-VASc score ≥4).

Mechanical Circulatory Support Devices in Acute Myocardial Infarction-Cardiogenic Shock: Current Studies and Future Directions

Cardiogenic shock (CS) caused by acute myocardial infarction (AMI) accounts for most deaths in the population with AMI and continues to be associated with high short-term mortality. Several temporary mechanical circulatory support (MCS) devices have been developed to treat CS and studied in randomized controlled trials (RCTs) of patients with AMI-CS. Unfortunately, none of these RCTs has demonstrated an improvement in survival with temporary MCS in AMI-CS. Potential reasons for these negative results in RCTs are numerous and reflect the challenges of enrolling critically ill patients with CS. Researchers have used observational study designs to provide insights about outcomes associated with the use of temporary MCS in AMI-CS. These observational studies have yielded conflicting results, in some cases contrary to the results of RCTs. Several limitations pertinent to both RCTs and observational analyses, mostly relating to selection bias and failure to consider unmeasured confounding variables and population heterogeneity, preclude drawing strong inferences regarding the effects of temporary MCS on survival in populations with AMI-CS. Understanding these limitations is essential to correctly interpreting the literature regarding temporary MCS to treat AMI-CS and is necessary to inform the design of future studies that will potentially provide stronger evidence. Optimally matching temporary MCS devices to the needs of individual patients with AMI-CS will presumably be more successful than indiscriminate application in unselected patients. In this review, we discuss the existing literature on temporary MCS to treat AMI-CS and describe the specific challenges that must be overcome to develop an improved evidence base for guiding clinical practice.

Increasing time between first diagnosis of atrial fibrillation and catheter ablation adversely affects long-term outcomes in patients with and without structural heart disease

INTRODUCTION

Atrial Fibrillation (AF) is a common arrhythmia often comorbid with systolic or diastolic heart failure (HF). Catheter ablation is a more effective treatment for AF with concurrent left ventricular dysfunction, however, the optimal timing of use in these patients is unknown.

METHODS

All patients that received a catheter ablation for AF(n = 9979) with 1 year of follow-up within the Intermountain Healthcare system were included. Patients with were identified by the presence of structural disease by ejection fraction (EF): EF ≤ 35% (n = 1024) and EF > 35% (n = 8955). Recursive partitioning categories were used to separate patients into clinically meaningful strata based upon time from initial AF diagnosis until ablation: 30-180(n = 2689), 2:181-545(n = 1747), 3:546-1825(n = 2941), and 4:>1825(n = 2602) days.

RESULTS

The mean days from AF diagnosis to first ablation was 3.5 ± 3.8 years (EF > 35%: 3.5 ± 3.8 years, EF ≤ 35%: 3.4 ± 3.8 years, p = .66). In the EF > 35% group, delays in treatment (181-545 vs. 30-180, 546-1825 vs. 30-180, >1825 vs. 30-180 days) increased the risk of death with a hazard ratio (HR) of 2.02(p < .0001), 2.62(p < .0001), and 4.39(p < .0001) respectively with significant risks for HF hospitalization (HR:1.44-3.69), stroke (HR:1.11-2.14), and AF recurrence (HR:1.42-1.81). In patients with an EF ≤ 35%, treatment delays also significantly increased risk of death (HR 2.07-3.77) with similar trends in HF hospitalization (HR:1.63-1.09) and AF recurrence (HR:0.79-1.24).

CONCLUSION

Delays in catheter ablation for AF resulted in increased all-cause mortality in all patients with differential impact observed on HF hospitalization, stroke, and AF recurrence risks by baseline EF. These data favor earlier use of ablation for AF in patients with and without structural heart disease.

Can Observational Analyses of Routinely Collected Data Emulate Randomized Trials? Design and Feasibility of the Observational Patient Evidence for Regulatory Approval Science and Understanding Disease Project

OBJECTIVES

The Observational Patient Evidence for Regulatory Approval Science and Understanding Disease (OPERAND) project examines whether real-world data (RWD) can be used to inform regulatory decision making.

METHODS

OPERAND evaluates whether observational analyses using RWD to emulate index trials can produce effect estimates similar to those of the trials and examines the impact of relaxing the eligibility criteria of the observational analyses to obtain samples that more closely match the real-world populations receiving the treatments. In OPERAND, 2 research teams independently attempt to emulate the ROCKET Atrial Fibrillation and LEAD-2 trials using OptumLabs data. This article describes the design of the project, summarizes the approaches of the 2 research teams, and presents feasibility results for 2 emulations using new-user designs.

RESULTS

There were differences in the teams' conceptualizations of the emulation, design decisions for cohort identification, and resulting RWD cohorts. These differences occurred even though both teams were guided by the same index trials and had access to the same source of RWD.

CONCLUSIONS

Reasonable alternative design and analysis approaches may be taken to answer the same research question, even when attempting to emulate the same index trial. Researcher decision making is an understudied and potentially important source of variability across RWD analyses.

Significance of mitral L-waves in predicting late recurrences of atrial fibrillation after radiofrequency catheter ablation

BACKGROUND

The mitral L-wave, a prominent mid-diastolic filling wave in echocardiographic examinations, is associated with severe left ventricular diastolic dysfunction. The relationship between the mitral L-wave and outcome of catheter ablation (CA) in patients with atrial fibrillation (AF) has not been established. This study aimed to evaluate the predictive value of mitral L-waves on AF recurrence after CA.

METHODS

This was a retrospective and observational study in a single center. One hundred forty-six patients (mean age; 63.9 [56.0-72.0] years, 71.9% male) including 66 non-paroxysmal AF patients (45.2%) who received a first CA were enrolled. The mitral L-waves were defined as a distinct mid-diastolic flow velocity with a peak velocity ≥20 cm/s following the E wave in the echocardiographic examinations before CA. The patients enrolled were divided into groups with (n = 31, 21.2%) and without (n = 115, 78.8%) mitral L-waves. Univariate and multivariate analyses were carried out to determine the predictive factors of late recurrences of AF (LRAFs), which meant AF recurrence later than 3 months after the CA.

RESULTS

During a follow-up of 28.8 (15.0-35.8) months, the ratio of LRAFs in patients with mitral L-waves was significantly higher than that in those without mitral L-waves (15 [46.9%] vs. 16 [14.0%], p < .001). A multivariate analysis using a Cox proportional hazard model revealed that the mitral L-waves were a significant predictive factor of LRAFs (hazard ratio: 3.09, 95% confidence interval: 1.53-6.24, p = .002).

CONCLUSION

The appearance of mitral L-waves could predict LRAFs after CA.

Efficacy and safety of novel pulsed field ablation (PFA) technique for atrial fibrillation: A systematic review and meta-analysis

Background and Aim

Pulse field ablation (PFA) has emerged as a safe alternative to other catheter ablation energy sources for patients. Although early results are encouraging, secondary data about outcomes are lacking. Herein, we aimed to assess the safety and efficacy of the novel technique.

Methods

We searched PubMed, Ovid, Google Scholar, Web of Science, and Scopus databases and several major scientific conferences for studies reporting results regarding PFA.

Results

Sixteen studies were included, reporting 485 patients with atrial fibrillation who underwent pulsed field operations. Patients averaged 60 years of age. The total duration of the procedure is 94 min. The average Fluoro procedure takes 17 min. Isolation of all pulmonary veins was 100% with a 95% confidence interval (CI) (p > 0.05). Overall, the recurrence rate of arrhythmia in the participants was 2.84% (95% CI) (p > 0.05). Complications were detected during or after the PFA procedure at a rate of 2.23% (p < 0.05), with 95% CI indicating the high safety of the PFA procedure.

Conclusion

Using pulsed-field ablation as a new treatment for atrial fibrillation has proven safe and effective.

Comparative risk of dementia among patients with atrial fibrillation treated with catheter ablation versus anti-arrhythmic drugs

Atrial fibrillation (AF) is associated with an increased risk of dementia. Emerging evidence suggests AF suppression is associated with reduced risk of dementia, but the optimal strategy to achieve this is unknown. We sought to compare the risk of dementia in patients with AF who underwent catheter ablation (CA) versus anti-arrhythmic drug (AAD) treatment. METHODS AND RESULTS: Using the 2000 to 2021 Optum Clinformatics database, patients with AF who underwent CA versus AAD treatment (≥1 prescription fill for ≥2 different AADs) were identified and propensity score matched overall and within sex subgroups. A cause-specific hazard model was performed to assess dementia overall and in sex-specific subgroups. After matching, there were 19,088 patients per group. CA was associated with a 41% lower risk of dementia compared with AAD alone (1.9% vs 3.3%; hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.52-0.67, log-rank P < .0001). When examined by sex, dementia risk reduction associated with CA versus AAD use alone was observed among both males (HR 0.55, 95% CI 0.46-0.66) and females (HR 0.60, 95% CI 0.50-0.72). Though not studied as a primary outcome, patients treated with CA were also observed to have 49% lower associated risk of mortality compared with AAD only (HR 0.51 95% CI 0.46-0.55, P < .0001). CONCLUSIONS: Among patients treated for AF, CA was associated with significantly lower risk of dementia and death compared with AADs only. These reductions in risk associated with CA versus AAD were seen in both males and females.

Experts' Views on FDA Regulatory Standards for Drug and High-Risk Medical Devices: Implications for Patient Care

BACKGROUND

Drugs and high-risk medical devices are increasingly likely to receive Food and Drug Administration (FDA) approval through expedited pathways, which has implications for informed treatment consent (i.e., consent in clinical practice).

OBJECTIVE

To obtain expert opinion about the clinical and ethical implications of the increasing availability of new drugs and devices approved through expedited development and regulatory review pathways.

DESIGN

Qualitative study using individual semi-structured videoconference interviews.

PARTICIPANTS

National leaders in medicine, ethics, and law (n=12) with expertise in medical product regulation, payor policymaking, bioethics, physician practice, patient advocacy, public health expertise/advocacy, clinical trials, the pharmaceutical and device industry, institutional review board oversight, and real-world evidence.

MAIN MEASURES

Principal themes in 3 domains: expedited regulatory pathways, physician and patient understanding of and reliance on FDA approval, and informed treatment consent.

KEY RESULTS

Respondents pointed out that more common use of expedited pathways translates to increased reliance on surrogate measures, some with uncertain clinical significance. While expedited development and review can have advantages, participants expressed worry that physicians were unaware when medical products were expedited and did not communicate about uncertainties in knowledge about new drug or device approvals effectively with patients. Many participants felt that informed treatment consent discussions about new drugs or devices should include some explanations of expedited pathways and use of surrogate measures.

CONCLUSIONS

Experts identified advantages of expediting development and of FDA flexibility in applying its standards to new drugs and medical devices, but highlighted concerns that patients may not be adequately informed about the risks of shorter review times or about uncertainties in the evidence that result. There is a need to identify approaches to ensure effective clinical use of drugs and devices when approved through expedited pathways.

Opportunities and challenges in heart rhythm research: Rationale and development of an electrophysiology collaboratory

There are many challenges in the current landscape of electrophysiology (EP) clinical and translational research, including increasing costs and complexity, competing demands, regulatory requirements, and challenges with study implementation. This review seeks to broadly discuss the state of EP research, including challenges and opportunities. Included here are results from a Heart Rhythm Society (HRS) Research Committee member survey detailing HRS members' perspectives regarding both barriers to clinical and translational research and opportunities to address these challenges. We also provide stakeholder perspectives on barriers and opportunities for future EP research, including input from representatives of the U.S. Food and Drug Administration, industry, and research funding institutions that participated in a Research Collaboratory Summit convened by HRS. This review further summarizes the experiences of the heart failure and heart valve communities and how they have approached similar challenges in their own fields. We then explore potential solutions, including various models of research ecosystems designed to identify research challenges and to coordinate ways to address them in a collaborative fashion in order to optimize innovation, increase efficiency of evidence generation, and advance the development of new therapeutic products. The objectives of the proposed collaborative cardiac EP research community are to encourage and support scientific discourse, research efficiency, and evidence generation by exploring collaborative and equitable solutions in which stakeholders within the EP community can interact to address knowledge gaps, innovate, and advance new therapies.

Economic Evaluation of Contact Force Catheter Ablation for Persistent Atrial Fibrillation in the United States

Background

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia, and it increases the risk of stroke, heart failure, and other cardiac complications. Catheter ablation is well-established as a treatment for paroxysmal AF, and the recent PRECEPT (Prospective Review of the Safety and Effectiveness of the THERMOCOOL SMARTTOUCH SF Catheter Evaluated for Treating Symptomatic Persistent AF) clinical trial resulted in the catheter gaining approval for the treatment of persistent AF in the United States.

Objectives

To construct an economic simulation model, based on the results of the PRECEPT trial, to monetize the impact of radiofrequency catheter ablation (RFCA) compared with medical therapy (MT).

Methods

Cost-offset and break-even analyses were performed to assess the economic impact of RFCA vs MT for adult persistent AF patients. Three perspectives were considered: commercial payers, Medicare, and self-insured employers. A cohort-level decision tree model was developed and validated in TreeAge Pro 2019. Sensitivity analyses were performed to determine the robustness of findings.

Results

For all 3 types of payer, RFCA had a higher initial cost compared with MT. However, reductions in health care utilization after ablation, driven by decreased cardiovascular hospitalizations, led to an annual cost offset of between $5037 and $8402 after the first year. Projecting this forward resulted in an estimated cost break-even after 5.9, 4.2, and 5.1 years for commercial payers, Medicare, and self-insured employers, respectively.

Conclusion

In addition to providing clinical benefits, RFCA may be a valuable economic investment for U.S. payers, substantially reducing utilization after the first year.

Insights from computational modeling on the potential hemodynamic effects of sinus rhythm versus atrial fibrillation

Atrial fibrillation (AF) is the most common clinical tachyarrhythmia, posing a significant burden to patients, physicians, and healthcare systems worldwide. With the advent of more effective rhythm control strategies, such as AF catheter ablation, an early rhythm control strategy is progressively demonstrating its superiority not only in symptoms control but also in prognostic terms, over a standard strategy (rate control, with rhythm control reserved only to patients with refractory symptoms). This review summarizes the different impacts exerted by AF on heart mechanics and systemic circulation, as well as on cerebral and coronary vascular beds, providing computational modeling-based hemodynamic insights in favor of pursuing sinus rhythm maintenance in AF patients.

Early diagnosis and better rhythm management to improve outcomes in patients with atrial fibrillation: the 8th AFNET/EHRA consensus conference

Despite marked progress in the management of atrial fibrillation (AF), detecting AF remains difficult and AF-related complications cause unacceptable morbidity and mortality even on optimal current therapy. This document summarizes the key outcomes of the 8th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA). Eighty-three international experts met in Hamburg for 2 days in October 2021. Results of the interdisciplinary, hybrid discussions in breakout groups and the plenary based on recently published and unpublished observations are summarized in this consensus paper to support improved care for patients with AF by guiding prevention, individualized management, and research strategies. The main outcomes are (i) new evidence supports a simple, scalable, and pragmatic population-based AF screening pathway; (ii) rhythm management is evolving from therapy aimed at improving symptoms to an integrated domain in the prevention of AF-related outcomes, especially in patients with recently diagnosed AF; (iii) improved characterization of atrial cardiomyopathy may help to identify patients in need for therapy; (iv) standardized assessment of cognitive function in patients with AF could lead to improvement in patient outcomes; and (v) artificial intelligence (AI) can support all of the above aims, but requires advanced interdisciplinary knowledge and collaboration as well as a better medico-legal framework. Implementation of new evidence-based approaches to AF screening and rhythm management can improve outcomes in patients with AF. Additional benefits are possible with further efforts to identify and target atrial cardiomyopathy and cognitive impairment, which can be facilitated by AI.

Economic Evaluation of Catheter Ablation Versus Medical Therapy for the Treatment of Atrial Fibrillation from the Perspective of the UK

Randomised evidence supports an early rhythm control strategy as treatment for AF, and catheter ablation outperforms medical therapy in terms of effectiveness when studied as first- and second-line treatment. Despite evidence consistently showing that catheter ablation treatment is superior to medical therapy in most AF patients, only a small proportion receive ablation, in some cases after a prolonged trial of ineffective medical therapy. Health economics research in electrophysiology remains limited but is recognised as being important in influencing positive change to ensure early access to ablation services for all eligible patients. Such information has informed the updated recommendations from the recently published National Institute for Health and Care Excellence clinical guideline on the diagnosis and management of AF, but increased awareness is needed to drive real-world adoption and to ensure patients are quickly referred to specialists. In this article, economic evaluations of catheter ablation versus medical therapy are reviewed.

Effect of hospital-at-home vs. traditional brick-and-mortar hospital care in acutely ill adults: study protocol for a pragmatic randomized controlled trial

BACKGROUND

Delivering acute hospital care to patients at home might reduce costs and improve patient experience. Mayo Clinic's Advanced Care at Home (ACH) program is a novel virtual hybrid model of "Hospital at Home." This pragmatic randomized controlled non-inferiority trial aims to compare two acute care delivery models: ACH vs. traditional brick-and-mortar hospital care in acutely ill patients.

METHODS

We aim to enroll 360 acutely ill adult patients (≥18 years) who are admitted to three hospitals in Arizona, Florida, and Wisconsin, two of which are academic medical centers and one is a community-based practice. The eligibility criteria will follow what is used in routine practice determined by local clinical teams, including clinical stability, social stability, health insurance plans, and zip codes. Patients will be randomized 1:1 to ACH or traditional inpatient care, stratified by site. The primary outcome is a composite outcome of all-cause mortality and 30-day readmission. Secondary outcomes include individual outcomes in the composite endpoint, fall with injury, medication errors, emergency room visit, transfer to intensive care unit (ICU), cost, the number of days alive out of hospital, and patient-reported quality of life. A mixed-methods study will be conducted with patients, clinicians, and other staff to investigate their experience.

DISCUSSION

The pragmatic trial will examine a novel virtual hybrid model for delivering high-acuity medical care at home. The findings will inform patient selection and future large-scale implementation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05212077. Registered on 27 January 2022.

One Year Outcomes of Atrial Fibrillation Ablation: Contemporary Analysis of the United States Nationwide Readmission Database

BACKGROUND

Data on long-term outcomes of catheter ablation (CA) for atrial fibrillation (AF) in outside of clinical trials settings are sparse.

OBJECTIVE

We aimed to assess outcomes and readmissions at 1 year following admission for CA for AF.

METHODS

Utilizing the Nationwide Readmissions Database (2016-2018), we identified patients with CA among all patients with a primary admission diagnosis of AF, and a control group by propensity score match adjusted for age, sex, comorbidities, CHA₂DS₂-VASc scores, and the hospital characteristics. The primary outcome was a composite of unplanned heart failure (HF), AF and stroke-related readmissions and death at 1 year, and secondary outcomes were hospital outcomes and all-cause readmission rates.

RESULTS

The study cohort consisted of 29,771 patients undergoing CA and 63,988 controls. Patients undergoing CA were younger with lower CHA₂DS₂-VASc scores and less comorbidities. Over a follow-up of 170 ±1.1 days, the primary outcome occurred in 5.2% in CA group and 6.0% of controls (hazard ratio [HR] and 95% confidence interval [CI]: 0.86 [0.76-0.94], p = 0.002). CA affected AF and stroke related readmission, but showed no effect on HF and mortality outcome.Male sex (HR: 0.83 [0.74-0.94], p = 0.03), younger age (HR: 0.71 [0.61-0.83], p<0.001], and lower CHA₂DS₂-VASc scores (HR: 0.68 [0.55-0.84], p<0.001) were associated with lower risk of primary outcome with CA.

CONCLUSION

In this study, CA for AF was associated with significantly lower AF and stroke-related admissions, but not to HF or all cause readmission. Better outcomes were seen among males, younger patients and in patients with less comorbidities and low CHA₂DS₂-VASc scores. This article is protected by copyright. All rights reserved.

Target Trial Emulation for Transparent and Robust Estimation of Treatment Effects for Health Technology Assessment Using Real-World Data: Opportunities and Challenges

Evidence about the relative effects of new treatments is typically collected in randomised controlled trials (RCTs). In many instances, evidence from RCTs falls short of the needs of health technology assessment (HTA). For example, RCTs may not be able to capture longer-term treatment effects, or include all relevant comparators and outcomes required for HTA purposes. Information routinely collected about patients and the care they receive have been increasingly used to complement RCT evidence on treatment effects. However, such routine (or real-world) data are not collected for research purposes, so investigators have little control over the way patients are selected into the study or allocated to the different treatment groups, introducing biases for example due to selection or confounding. A promising approach to minimise common biases in non-randomised studies that use real-world data (RWD) is to apply design principles from RCTs. This approach, known as 'target trial emulation' (TTE), involves (1) developing the protocol with respect to core study design and analysis components of the hypothetical RCT that would answer the question of interest, and (2) applying this protocol to the RWD so that it mimics the data that would have been gathered for the RCT. By making the 'target trial' explicit, TTE helps avoid common design flaws and methodological pitfalls in the analysis of non-randomised studies, keeping each step transparent and accessible. It provides a coherent framework that embeds existing analytical methods to minimise confounding and helps identify potential limitations of RWD and the extent to which these affect the HTA decision. This paper provides a broad overview of TTE and discusses the opportunities and challenges of using this approach in HTA. We describe the basic principles of trial emulation, outline some areas where TTE using RWD can help complement RCT evidence in HTA, identify potential barriers to its adoption in the HTA setting and highlight some priorities for future work.

Generalizability of the EAST-AFNET 4 Trial: Assessing Outcomes of Early Rhythm-Control Therapy in Patients With Atrial Fibrillation

Background

EAST‐AFNET 4 (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial) demonstrated clinical benefit of early rhythm‐control therapy (ERC) in patients with new‐onset atrial fibrillation (AF) and concomitant cardiovascular conditions compared with current guideline‐based practice. This study aimed to evaluate the generalizability of EAST‐AFNET 4 in routine practice.

Methods and Results

Using a US administrative database, we identified 109 739 patients with newly diagnosed AF during the enrollment period of EAST‐AFNET 4. Patients were classified as either receiving ERC, using AF ablation or antiarrhythmic drug therapy, within the first year after AF diagnosis (n=27 106) or not receiving ERC (control group, n=82 633). After propensity score overlap weighting, Cox proportional hazards regression was used to compare groups for the primary composite outcome of all‐cause mortality, stroke, or hospitalization with the diagnoses heart failure or myocardial infarction. Most patients (79 948 of 109 739; 72.9%) met the inclusion criteria for EAST‐AFNET 4. ERC was associated with a reduced risk for the primary composite outcome (hazard ratio [HR], 0.85; 95% CI, 0.75–0.97 [P=0.02]) with largely consistent results between eligible (HR, 0.89; 95% CI, 0.76–1.04 [P=0.14]) or ineligible (HR, 0.77; 95% CI, 0.60–0.98 [P=0.04]) patients for EAST‐AFNET 4 trial inclusion. ERC was associated with lower risk of stroke in the overall cohort and in trial‐eligible patients.

Conclusions

This analysis replicates the clinical benefit of ERC seen in EAST‐AFNET 4. The results support adoption of ERC as part of the management of recently diagnosed AF in the United States.

Heart failure and catheter ablation of atrial fibrillation: Navigating the difficult waters of heart failure phenotypes

The use of catheter ablation of atrial fibrillation (AFA) is increasing and it has now been extended to include higher risk patients with heart failure (HF), based on evidence from observational studies and meta-analyses of randomized controlled trials (RCTs) indicating it as safe and beneficial in terms of quality of life, AF recurrence and hospital readmissions in the short-to-middle term. However, the RCTs so far have been relatively small with short follow-up, and few larger trials with long follow-up inconclusive about hard outcomes for large patient crossover undermining the robustness of the results. Importantly, most RCTs involved HF patients with reduced left ventricular ejection fraction (HFrEF). In contrast, most observational studies show that the majority of ablated HF patients in clinical practice have a preserved ejection fraction (HFpEF), a condition representing roughly half of all HF patients. This article provides an overview of the available scientific evidence in this clinical field and examines the current guideline recommendations. In the absence of robust evidence-based research, the recommendations on AFA in HF may be inconsistent or abstain from taking firm positions, particularly regarding AFA in HFpEF. There is need for clinical research in such a surprisingly orphan setting, in parallel with the current attempts to sort out the knotty question of the HF phenotypes, in particular, again, of the HFpEF phenotypes.

Safety of Catheter Ablation for Atrial Fibrillation in Patients with Mechanical Prosthetic Valves

BACKGROUND

Catheter ablation (CA) for Atrial Fibrillation (AF) is increasingly utilized in the recent years, with promising results. We aimed to investigate the nationwide trends in utilization and procedural complications of CA for AF in patients with mechanical prosthetic valves (MPVs).

METHODS AND RESULTS

We drew data from the US National Inpatient Sample (NIS) database to identify cases of AF ablations in patients with MPVs, between 2003-2015. Sociodemographic and clinical data were collected, and incidence of procedural complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity matched cohort of patients without MPVs. The study included a weighted total of 1898 CA for AF cases in patients with MPVs. The median age of the study population was 67 (61-75) years and 53% were males. Despite the increasing age and significant uptrend in the prevalence of individual comorbidities and Deyo - Charlson Comorbidity Index (CCI) over the years, the risk of peri-procedural complications and mortality in the study group didn't change between the early (2003-2008) and late (2009-2015) study years. The peri-procedural complication rate (8.4% vs 10.4%, p=0.33) and in-hospital mortality (0.2% vs. 0.2%, p=0.9) did not differ significantly between patients with MPVs and 1901 matched patients without MPVs. Length of stay was higher among patients with prior MPVs compared to the controls (4.0±0.2 vs. 3.3±0.2 days, p=0.011).

CONCLUSION

This nationwide analysis shows that AF ablation in patients with mechanical valve prostheses bares similar risk of periprocedural complications and mortality as in patients without prosthetic valves. This article is protected by copyright. All rights reserved.

Association Between Age and Outcomes of Catheter Ablation Versus Medical Therapy for Atrial Fibrillation: Results From the CABANA Trial

BACKGROUND

Observational data suggest that catheter ablation may be safe and effective to treat younger and older patients with atrial fibrillation. No large, randomized trial has examined this issue. This report describes outcomes according to age at entry in the CABANA trial (Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation).

METHODS

Patients with atrial fibrillation ≥65 years of age, or <65 with ≥1 risk factor for stroke, were randomly assigned to catheter ablation versus drug therapy. The primary outcome was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Secondary outcomes included all-cause mortality, the composite of mortality or cardiovascular hospitalization, and recurrence of atrial fibrillation. Treatment effect estimates were adjusted for baseline covariables using proportional hazards regression models.

RESULTS

Of 2204 patients randomly assigned in CABANA, 766 (34.8%) were <65 years of age, 1130 (51.3%) were 65 to 74 years of age, and 308 (14.0%) were ≥75 years of age. Catheter ablation was associated with a 43% reduction in the primary outcome for patients <65 years of age (adjusted hazard ratio [aHR], 0.57 [95% CI, 0.30-1.09]), a 21% reduction for 65 to 74 years of age (aHR, 0.79 [95% CI, 0.54-1.16]), and an indeterminate effect for age ≥75 years of age (aHR, 1.39 [95% CI, 0.75-2.58]). Four-year event rates for ablation versus drug therapy across age groups, respectively, were 3.2% versus 7.8%, 7.8% versus 9.6%, and 14.8% versus 9.0%. For every 10-year increase in age, the primary outcome aHR increased (ie, less favorable to ablation) an average of 27% (interaction P value=0.215). A similar pattern was seen with all-cause mortality: for every 10-year increase in age, the aHR increased an average of 46% (interaction P value=0.111). Atrial fibrillation recurrence rates were lower with ablation than with drug therapy across age subgroups (aHR 0.47, 0.58, and 0.49, respectively). Treatment-related complications were infrequent for both arms (<3%) regardless of age.

CONCLUSIONS

We found age-based variations in clinical outcomes for catheter ablation compared with drug therapy, with the largest relative and absolute benefits of catheter ablation in younger patients. No prognostic benefits for ablation were seen in the oldest patients. No differences were found by age in treatment-related complications or in the relative effectiveness of catheter ablation in preventing recurrent atrial arrhythmias.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT00911508.

Very early versus early referral for ablation among young patients for newly diagnosed paroxysmal atrial fibrillation

BACKGROUND

Catheter ablation (CA) has emerged as an effective therapy for the treatment of paroxysmal atrial fibrillation, however it is unclear whether proceeding expeditiously to CA improves clinical outcomes in a real-world population. This study compares outcomes of catheter ablation for new atrial fibrillation (AF) within 6 months of diagnosis (very early) 6 to 12 months after diagnosis (early) and 12 to 24 months after diagnosis (later).

METHODS

A large nationally-representative sample of patients ages 18 to 64 who underwent CA from January 2011 to June 2019 was studied using the IBM MarketScan® Database. The primary outcome was a composite of healthcare utilization over the following 24 months. Propensity score-matching was used to match patients in each cohort. Risk difference in outcomes were compared between matched patients.

RESULTS

2,631 patients were identified post-matching, with 1,649 in the very early cohort and 982 in the early cohort. The very early referral group was less likely to experience the primary composite outcome post-ablation (Absolute risk difference [ARD]: -3.9%; 95% Confidence interval [CI]: -5.8%, -2.0%), with the difference driven by fewer cardioversions (ARD: -2.9%, 95% CI: -5.3%, -0.5%) and outpatient visits (ARD: -6.6%, 95% CI: -10.5%, -2.7%). There was no difference in outcomes between early and later referral groups, with only very early referral showing decreased healthcare utilization.

CONCLUSIONS

Patients who underwent ablation within 6 months of diagnosis had lower healthcare utilization in the ensuing 24 months, driven by fewer outpatient visits and cardioversions, supporting expeditious referral for ablation for symptomatic AF. This article is protected by copyright. All rights reserved.

Atrial fibrillation ablation in heart failure: Findings from the ESC-EHRA EORP Atrial Fibrillation Ablation long-term (AFA LT) registry

BACKGROUND

The current practice of atrial fibrillation ablation (AFA) as a treatment option for atrial fibrillation (AF) in patients with heart failure (HF) across Europe, their clinical profiles and outcomes is still undefined.

METHODS

The European Society of Cardiology (ESC) led a prospective observational registry of consecutive patients undergoing AFA, in 27 member countries. The subgroup of patients with HF, followed-up for 1 year, was analyzed and the results are reported.

RESULTS

Of the 3582 AF patients in the Registry, 537 (14.9%) had HF. Diabetes, hypertension, hypercholesterolemia, CHA₂DS₂-VASc score ≥ 2, structural heart disease and persistent AF were more common in HF than non-HF patients (all p < 0.001). However the in-hospital complications were less frequent in HF patients (5.0% vs. 8.2% p = 0.01). Both in-hospital and 1-year outcomes, including 1-year AF recurrence (15.4%) and repeat ablations (9.5%), were similar in both groups. We subdivided HF patients according to their left ventricular ejection fraction (EF) at baseline into reduced (HFrEF, <40%), mid-range (HFmEF, 40-49%), or preserved EF (HFpEF, ≥ 50%). Most patients were HFpEF (n 375, 77%), 72 (15%) were HFmEF and 8% HFrEF. The most frequent underlying conditions in HFpEF were hypertension and ischemic heart disease, while those most common in HFmEF and HFrEF were valvular and dilated cardiomyopathy.

CONCLUSION

In routine care in Europe, HF patients represent a minority of patients undergoing AFA, and most belong to the HFpEF phenotype. The limited clinical research on AFA HFpEF patients is reflected by the uncertainty expressed in the current AF Guidelines and Expert statements.

Catheter ablation versus medical therapy for atrial fibrillation: Penny-wise Pound-foolish

Catheter ablation for atrial fibrillation has emerged as a mainstay for the management of atrial fibrillation. It has been shown to be clinically effective and cost-effective in multiple trials.

Cost-effectiveness of catheter ablation versus medical therapy for the treatment of atrial fibrillation in the United Kingdom

Introduction

Research evidence has shown that catheter ablation is a safe and superior treatment for atrial fibrillation (AF) compared to medical therapy, but real‐world practice has been slow to adopt an early interventional approach. This study aims to determine the cost effectiveness of catheter ablation compared to medical therapy from the perspective of the United Kingdom.

Methods

A patient‐level Markov health‐state transition model was used to conduct a cost‐utility analysis. The population included patients previously treated for AF with medical therapy, including those with heart failure (HF), simulated over a lifetime horizon. Data sources included published literature on utilization and cardiovascular event rates in real world patients, a systematic literature review and meta‐analysis of randomized controlled trials for AF recurrence, and publicly available government data/reports on costs.

Results

Catheter ablation resulted in a favorable incremental cost‐effectiveness ratio (ICER) of £8614 per additional quality adjusted life years (QALY) gained when compared to medical therapy. More patients in the medical therapy group failed rhythm control at any point compared to catheter ablation (72% vs. 24%) and at a faster rate (median time to treatment failure: 3.8 vs. 10 years). Additionally, catheter ablation was estimated to be more cost‐effective in patients with AF and HF (ICER = £6438) and remained cost‐effective over all tested time horizons (10, 15, and 20 years), with the ICER ranging from £9047–£15 737 per QALY gained.

Conclusion

Catheter ablation is a cost‐effective treatment for atrial fibrillation, compared to medical therapy, from the perspective of the UK National Health Service.

Comparative effectiveness and safety of pharmaceuticals assessed in observational studies compared with randomized controlled trials

BACKGROUND

There have been ongoing efforts to understand when and how data from observational studies can be applied to clinical and regulatory decision making. The objective of this review was to assess the comparability of relative treatment effects of pharmaceuticals from observational studies and randomized controlled trials (RCTs).

METHODS

We searched PubMed and Embase for systematic literature reviews published between January 1, 1990, and January 31, 2020, that reported relative treatment effects of pharmaceuticals from both observational studies and RCTs. We extracted pooled relative effect estimates from observational studies and RCTs for each outcome, intervention-comparator, or indication assessed in the reviews. We calculated the ratio of the relative effect estimate from observational studies over that from RCTs, along with the corresponding 95% confidence interval (CI) for each pair of pooled RCT and observational study estimates, and we evaluated the consistency in relative treatment effects.

RESULTS

Thirty systematic reviews across 7 therapeutic areas were identified from the literature. We analyzed 74 pairs of pooled relative effect estimates from RCTs and observational studies from 29 reviews. There was no statistically significant difference (based on the 95% CI) in relative effect estimates between RCTs and observational studies in 79.7% of pairs. There was an extreme difference (ratio < 0.7 or > 1.43) in 43.2% of pairs, and, in 17.6% of pairs, there was a significant difference and the estimates pointed in opposite directions.

CONCLUSIONS

Overall, our review shows that while there is no significant difference in the relative risk ratios between the majority of RCTs and observational studies compared, there is significant variation in about 20% of comparisons. The source of this variation should be the subject of further inquiry to elucidate how much of the variation is due to differences in patient populations versus biased estimates arising from issues with study design or analytical/statistical methods.

Machine Learning Methodologies for Prediction of Rhythm-Control Strategy in Patients Diagnosed With Atrial Fibrillation: Observational, Retrospective, Case-Control Study

Background

The identification of an appropriate rhythm management strategy for patients diagnosed with atrial fibrillation (AF) remains a major challenge for providers. Although clinical trials have identified subgroups of patients in whom a rate- or rhythm-control strategy might be indicated to improve outcomes, the wide range of presentations and risk factors among patients presenting with AF makes such approaches challenging. The strength of electronic health records is the ability to build in logic to guide management decisions, such that the system can automatically identify patients in whom a rhythm-control strategy is more likely and can promote efficient referrals to specialists. However, like any clinical decision support tool, there is a balance between interpretability and accurate prediction.

Objective

This study aims to create an electronic health record–based prediction tool to guide patient referral to specialists for rhythm-control management by comparing different machine learning algorithms.

Methods

We compared machine learning models of increasing complexity and used up to 50,845 variables to predict the rhythm-control strategy in 42,022 patients within the University of Colorado Health system at the time of AF diagnosis. Models were evaluated on the basis of their classification accuracy, defined by the F1 score and other metrics, and interpretability, captured by inspection of the relative importance of each predictor.

Results

We found that age was by far the strongest single predictor of a rhythm-control strategy but that greater accuracy could be achieved with more complex models incorporating neural networks and more predictors for each participant. We determined that the impact of better prediction models was notable primarily in the rate of inappropriate referrals for rhythm-control, in which more complex models provided an average of 20% fewer inappropriate referrals than simpler, more interpretable models.

Conclusions

We conclude that any health care system seeking to incorporate algorithms to guide rhythm management for patients with AF will need to address this trade-off between prediction accuracy and model interpretability.

Residual Stroke Risk in Atrial Fibrillation

AF contributes to increased stroke risk via various mechanisms, including deranged blood constituents, vessel wall abnormalities and abnormal blood flow. This excess risk is frequently managed with anticoagulation therapy, aimed at preventing thromboembolic complications. Yet, a significant proportion of patients with AF remain at high residual stroke risk despite receiving appropriate dose-adjusted anticoagulation. This article explores the residual stroke risk in AF and potential therapeutic options for these patients.

Atrial fibrillation and the risk of ischaemic strokes or intracranial haemorrhages: comparisons of the catheter ablation, medical therapy, and non-atrial fibrillation population

AIMS

Although atrial fibrillation (AF) catheter ablation (AFCA) is an effective rhythm control strategy, there is limited data on whether ischaemic stroke (IS) or intracranial haemorrhage (ICH) decreases after AFCA compared with medical therapy or non-AF population. We explored the IS and ICH risk after AFCA or medical therapy in the AF population and matched non-AF population.

METHODS AND RESULTS

We compared 1629 patients with AFCA (Yonsei AF ablation cohort), 3258 with medical therapy [Korean National Health Insurance (NHIS) database], and 3258 non-AF subjects (NHIS database) following a 1:2:2 propensity score matching. All AFCA patients underwent regular rhythm follow-ups for 51 ± 29 months. Among the AFCA group, the incidence rate ratio (IRR) of ISs was significantly higher in patients with sustained AF recurrences after the last ablation (0.87%) than in those remaining in sinus rhythm (0.24%, P = 0.017; log rank P = 0.003). The IRR of ISs was significantly higher in the medical therapy (1.09%) than AFCA (0.30%, P < 0.001, log rank P < 0.001 vs. medical therapy) or non-AF groups (0.34%, P < 0.001, log rank P < 0.001 vs. medical therapy; P = 0.673, log rank P = 0.874 vs. AFCA). The IRR of ICHs was 0.17% in the medical therapy, 0.06% in the AFCA (P = 0.023, log rank P = 0.042 vs. medical therapy), and 0.12% in the non-AF group (P = 0.226, log rank P = 0.241 vs. medical therapy; P = 0.172, log rank P = 0.193 vs. AFCA).

CONCLUSION

Post-procedural AF control influences the risk of ISs. Atrial fibrillation catheter ablation significantly reduces the risk of both ISs and ICHs to the extent of the non-AF population compared to the medical therapy.

Ablation Versus Drug Therapy for Atrial Fibrillation in Racial and Ethnic Minorities

BACKGROUND

Rhythm control strategies for atrial fibrillation (AF), including catheter ablation, are substantially underused in racial/ethnic minorities in North America.

OBJECTIVES

This study sought to describe outcomes in the CABANA trial as a function of race/ethnicity.

METHODS

CABANA randomized 2,204 symptomatic participants with AF to ablation or drug therapy including rate and/or rhythm control drugs. Only participants in North America were included in the present analysis, and participants were subgrouped as racial/ethnic minority or nonminority with the use of National Institutes of Health definitions. The primary endpoint was a composite of death, disabling stroke, serious bleeding, or cardiac arrest.

RESULTS

Of 1,280 participants enrolled in CABANA in North America, 127 (9.9%) were racial and ethnic minorities. Compared with nonminorities, racial and ethnic minorities were younger with median age 65.6 versus 68.5 years, respectively, and had more symptomatic heart failure (37.0% vs 22.0%), hypertension (92.1% vs 76.8%, respectively), and ejection fraction <40% (20.8% vs 7.1%). Racial/ethnic minorities treated with ablation had a 68% relative reduction in the primary endpoint (adjusted hazard ratio [aHR]: 0.32; 95% confidence interval [CI]: 0.13-0.78) and a 72% relative reduction in all-cause mortality (aHR: 0.28; 95% CI: 0.10-0.79). Primary event rates in racial/ethnic minority and nonminority participants were similar in the ablation arm (4-year Kaplan-Meier event rates 12.3% vs 9.9%); however, racial and ethnic minorities randomized to drug therapy had a much higher event rate than nonminority participants (27.4% vs. 9.4%).

CONCLUSION

Among racial or ethnic minorities enrolled in the North American CABANA cohort, catheter ablation significantly improved major clinical outcomes compared with drug therapy. These benefits, which were not seen in nonminority participants, appear to be due to worse outcomes with drug therapy. (Catheter Ablation vs Anti-arrhythmic Drug Therapy for Atrial Fibrillation Trial [CABANA]; NCT00911508).

Assessment of Catheter Ablation or Antiarrhythmic Drugs for First-line Therapy of Atrial Fibrillation: A Meta-analysis of Randomized Clinical Trials

Importance

Early rhythm control of atrial fibrillation (AF) with either antiarrhythmic drugs (AADs) or catheter ablation has been reported to improve cardiovascular outcomes compared with usual care; however, the optimal therapeutic modality to achieve early rhythm control is unclear.

Objective

To assess the safety and efficacy of AF ablation as first-line therapy when compared with AADs in patients with paroxysmal AF.

Data Sources

PubMed/MEDLINE, Scopus, Google Scholar, and various major scientific conference sessions from January 1, 2000, through November 23, 2020.

Study Selection

Randomized clinical trials (RCTs) published in English that had at least 12 months of follow-up and compared clinical outcomes of ablation vs AADs as first-line therapy in adults with AF. The quality of individual studies was assessed using the Cochrane risk of bias tool. Six RCTs met inclusion criteria, including 1212 patients.

Data Extraction and Synthesis

Two investigators independently extracted data. Reporting was performed in compliance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines. Analysis was performed using a random-effects model with the Mantel-Haenszel method, and results are presented as 95% CIs.

Main Outcomes and Measures

Main outcomes were safety and efficacy of AF ablation as first-line therapy when compared with AADs. Trials were evaluated as having low risk of selection and attrition biases, high risk of performance bias, and with unclear risk for detection biases due to unblinding and open-label designs.

Results

A total of 6 RCTs involving 1212 patients with AF were included (609 were randomized to AF ablation and 603 to drug therapy; mean [SD] age, 56 [11] years). Compared with AADs, catheter ablation use was associated with reductions in recurrent atrial arrhythmia (32.3% vs 53%; risk ratio [RR], 0.62; 95% CI, 0.51-0.74; P < .001; I2 = 40%), with a number needed to treat with ablation to prevent 1 arrhythmia of 5. Use of ablation was also associated with reduced symptomatic atrial arrhythmia (11.8% vs 26.4%; RR, 0.44; 95% CI, 0.27-0.72; P = .001; I2 = 54%) and hospitalization (5.6% vs 18.7%; RR, 0.32; 95% CI, 0.19-0.53; P < .001) with no significant difference in serious adverse events between the groups (4.2% vs 2.8%; RR, 1.52; 95% CI, 0.81-2.85; P = .19).

Conclusions and Relevance

In this meta-analysis of randomized clinical trials including first-line therapy of patients with paroxysmal AF, catheter ablation compared with antiarrhythmic drugs was associated with reductions in recurrence of atrial arrhythmias and hospitalizations, with no difference in major adverse events.

Computational Modeling for Antiarrhythmic Drugs for Atrial Fibrillation According to Genotype

Background: The efficacy of antiarrhythmic drugs (AAD) can vary in patients with atrial fibrillation (AF), and the PITX2 gene affects the responsiveness of AADs. We explored the virtual AAD (V-AAD) responses between wild-type and PITX2 ^+/--deficient AF conditions by realistic in silico AF modeling. Methods: We tested the V-AADs in AF modeling integrated with patients' 3D-computed tomography and 3D-electroanatomical mapping, acquired in 25 patients (68% male, 59.8 ± 9.8 years old, 32.0% paroxysmal type). The ion currents for the PITX2 ^+/- deficiency and each AAD (amiodarone, sotalol, dronedarone, flecainide, and propafenone) were defined based on previous publications. Results: We compared the wild-type and PITX2 ^+/- deficiency in terms of the action potential duration (APD₉₀), conduction velocity (CV), maximal slope of restitution (Smax), and wave-dynamic parameters, such as the dominant frequency (DF), phase singularities (PS), and AF termination rates according to the V-AADs. The PITX2 ^+/--deficient model exhibited a shorter APD₉₀ (p < 0.001), a lower Smax (p < 0.001), mean DF (p = 0.012), PS number (p < 0.001), and a longer AF cycle length (AFCL, p = 0.011). Five V-AADs changed the electrophysiology in a dose-dependent manner. AAD-induced AFCL lengthening (p < 0.001) and reductions in the CV (p = 0.033), peak DF (p < 0.001), and PS number (p < 0.001) were more significant in PITX2 ^+/--deficient than wild-type AF. PITX2 ^+/--deficient AF was easier to terminate with class IC AADs than the wild-type AF (p = 0.018). Conclusions: The computational modeling-guided AAD test was feasible for evaluating the efficacy of multiple AADs in patients with AF. AF wave-dynamic and electrophysiological characteristics are different among the PITX2-deficient and the wild-type genotype models.

Clinical outcomes following rhythm control for atrial fibrillation: is early better?

Introduction: An integral aspect of atrial fibrillation (AF) management involves better symptom control, incorporating a rate control, rhythm control, or a combination strategy. The 2020 ESC Guidelines suggest that rhythm control strategy should be recommended for symptomatic patients, to mitigate their symptoms and improve the quality of life. However, adequately powered randomized control trials and prospective 'real-world' registries are needed to fully assess the impact of early rhythm control strategies on clinical outcomes in patients with AF.Objective: In this narrative review, we discuss clinical outcomes following rhythm management approach among patients with AF, considering the effectiveness of an early intervention strategy.Expert opinion: Patients involvement and shared decision-making are crucial when deciding the optimal management strategy among patients with AF. For those with newly diagnosed symptomatic AF, an early invasive approach such as catheter ablation may have a role in preventing AF progression and subsequent pathophysiological changes.

Limited duration of antiarrhythmic drug use for newly diagnosed atrial fibrillation in a nationwide population under age 65

INTRODUCTION

Antiarrhythmic drugs (AADs) are commonly used for the treatment of newly diagnosed symptomatic atrial fibrillation (AF), however initial AAD choice, duration of therapy, rates of discontinuation, and factors associated with a durable response to therapy are poorly understood. This study assesses the initial choice and duration of antiarrhythmic drug therapy in the first 2 years after diagnosis of AF in a younger, commercially insured population.

METHODS

A large nationally representative sample of patients age 20-64 was studied using the IBM MarketScan Database. Patients who started an AAD within 90 days of AF diagnosis with continuous enrollment for 1-year pre-index diagnosis and 2 years post-index were included. A Cox proportional hazards model was used to determine factors associated with AAD discontinuation.

RESULTS

Flecainide was used most frequently (26.8%), followed by amiodarone (22.5%), dronedarone (18.3%), sotalol (15.8%), and propafenone (14.0%), with other AADs used less frequently. Twenty-two percent of patients who started on an AAD underwent ablation within 2 years, with 79% discontinuing the AAD after ablation. Ablation was the strongest predictor of AAD discontinuation (hazard ratio [HR], 1.70; 95% confidence interval [CI]: 1.61-1.80), followed by the male gender (HR, 1.10; CI: 1.02-1.19). Older patients (HR, 0.76; CI: 0.72-0.80; reference age 18-49) and those with comorbidities, including cardiomyopathy (HR, 075; CI: 0.61-0.91), diabetes (HR, 0.83; CI: 0.75-0.91), and hypertension (HR, 0.87; CI: 0.81-0.94) were less likely to discontinue AADs.

CONCLUSION

Only 31% of patients remained on the initial AAD at 2 years, with a mean duration of initial therapy 7.6 months before discontinuation.