Progression of Atrial Fibrillation after Cryoablation or Drug Therapy.

BACKGROUND: Atrial fibrillation is a chronic, progressive disorder, and persistent forms of atrial fibrillation are associated with increased risks of thromboembolism and heart failure. Catheter ablation as initial therapy may modify the pathogenic mechanism of atrial fibrillation and alter progression to persistent atrial fibrillation. METHODS: We report the 3-year follow-up of patients with paroxysmal, untreated atrial fibrillation who were enrolled in a trial in which they had been randomly assigned to undergo initial rhythm-control therapy with cryoballoon ablation or to receive antiarrhythmic drug therapy. All the patients had implantable loop recorders placed at the time of trial entry, and evaluation was conducted by means of downloaded daily recordings and in-person visits every 6 months. Data regarding the first episode of persistent atrial fibrillation (lasting ≥7 days or lasting 48 hours to 7 days but requiring cardioversion for termination), recurrent atrial tachyarrhythmia (defined as atrial fibrillation, flutter, or tachycardia lasting ≥30 seconds), the burden of atrial fibrillation (percentage of time in atrial fibrillation), quality-of-life metrics, health care utilization, and safety were collected. RESULTS: A total of 303 patients were enrolled, with 154 patients assigned to undergo initial rhythm-control therapy with cryoballoon ablation and 149 assigned to receive antiarrhythmic drug therapy. Over 36 months of follow-up, 3 patients (1.9%) in the ablation group had an episode of persistent atrial fibrillation, as compared with 11 patients (7.4%) in the antiarrhythmic drug group (hazard ratio, 0.25; 95% confidence interval [CI], 0.09 to 0.70). Recurrent atrial tachyarrhythmia occurred in 87 patients in the ablation group (56.5%) and in 115 in the antiarrhythmic drug group (77.2%) (hazard ratio, 0.51; 95% CI, 0.38 to 0.67). The median percentage of time in atrial fibrillation was 0.00% (interquartile range, 0.00 to 0.12) in the ablation group and 0.24% (interquartile range, 0.01 to 0.94) in the antiarrhythmic drug group. At 3 years, 8 patients (5.2%) in the ablation group and 25 (16.8%) in the antiarrhythmic drug group had been hospitalized (relative risk, 0.31; 95% CI, 0.14 to 0.66). Serious adverse events occurred in 7 patients (4.5%) in the ablation group and in 15 (10.1%) in the antiarrhythmic drug group. CONCLUSIONS: Initial treatment of paroxysmal atrial fibrillation with catheter cryoballoon ablation was associated with a lower incidence of persistent atrial fibrillation or recurrent atrial tachyarrhythmia over 3 years of follow-up than initial use of antiarrhythmic drugs. (Funded by the Cardiac Arrhythmia Network of Canada and others; EARLY-AF ClinicalTrials.gov number, NCT02825979.).

Atrial fibrillation progression after cryoablation vs. radiofrequency ablation: the CIRCA-DOSE trial.

BACKGROUND AND AIMS: Atrial fibrillation (AF) is a chronic progressive disorder. Persistent forms of AF are associated with increased rates of thromboembolism, heart failure, and death. Catheter ablation modifies the pathogenic mechanism of AF progression. No randomized studies have evaluated the impact of the ablation energy on progression to persistent atrial tachyarrhythmia. METHODS: Three hundred forty-six patients with drug-refractory paroxysmal AF were enrolled and randomly assigned to contact-force-guided RF ablation (CF-RF ablation, 115), 4 min cryoballoon ablation (CRYO-4, 115), or 2 min cryoballoon ablation (CRYO-2, 116). Implantable cardiac monitors placed at study entry were used for follow-up. The main outcome was the first episode of persistent atrial tachyarrhythmia. Secondary outcomes included atrial tachyarrhythmia recurrence and arrhythmia burden on the implantable monitor. RESULTS: At a median of 944.0 (interquartile range [IQR], 612.5-1104) days, 0 of 115 patients (0.0%) randomly assigned to CF-RF, 8 of 115 patients (7.0%) assigned to CRYO-4, and 5 of 116 patients (4.3%) assigned to CRYO-2 experienced an episode of persistent atrial tachyarrhythmia (P = .03). A documented recurrence of any atrial tachyarrhythmia ≥30 s occurred in 56.5%, 53.9%, and 62.9% of those randomized to CF-RF, CRYO-4, and CRYO-2, respectively; P = .65. Compared with that of the pre-ablation monitoring period, AF burden was reduced by a median of 99.5% (IQR 94.0%, 100.0%) with CF-RF, 99.9% (IQR 93.3%-100.0%) with CRYO-4, and 99.1%% (IQR 87.0%-100.0%) with CRYO-2 (P = .38). CONCLUSIONS: Catheter ablation of paroxysmal AF using radiofrequency energy was associated with fewer patients developing persistent AF on follow-up.

What Do We Really Know About the Effect of Prolonged Heart Rhythm Monitoring After Stroke?

The bulk of the current knowledge on atrial fibrillation (AF)-associated stroke risk and benefit of oral anticoagulation derives from studies on patients with clinically diagnosed AF. Subclinical AF (SCAF), defined as AF discovered during the interrogation of prolonged heart monitoring, is often asymptomatic and short-lasting, is associated with increased stroke risk compared with sinus rhythm, and may progress to clinical AF. Despite the extensive screening for and treatment of SCAF, especially in secondary stroke prevention, the net benefit of this practice is not established. Recent studies of SCAF have provided new insights: (1) SCAF is extremely common and may sometimes indicate physiological findings, (2) the stroke risk associated with SCAF is lower than that of clinically detected AF, and (3) any benefit on stroke risk may be countered by increased bleeding risk (no net benefit). How should we interpret the latest knowledge in the setting of poststroke AF screening and prevention?

Cryoablation or Drug Therapy for Initial Treatment of Atrial Fibrillation.

BACKGROUND: Guidelines recommend a trial of one or more antiarrhythmic drugs before catheter ablation is considered in patients with atrial fibrillation. However, first-line ablation may be more effective in maintaining sinus rhythm. METHODS: We randomly assigned 303 patients with symptomatic, paroxysmal, untreated atrial fibrillation to undergo catheter ablation with a cryothermy balloon or to receive antiarrhythmic drug therapy for initial rhythm control. All the patients received an implantable cardiac monitoring device to detect atrial tachyarrhythmia. The follow-up period was 12 months. The primary end point was the first documented recurrence of any atrial tachyarrhythmia (atrial fibrillation, atrial flutter, or atrial tachycardia) between 91 and 365 days after catheter ablation or the initiation of an antiarrhythmic drug. The secondary end points included freedom from symptomatic arrhythmia, the atrial fibrillation burden, and quality of life. RESULTS: At 1 year, a recurrence of atrial tachyarrhythmia had occurred in 66 of 154 patients (42.9%) assigned to undergo ablation and in 101 of 149 patients (67.8%) assigned to receive antiarrhythmic drugs (hazard ratio, 0.48; 95% confidence interval [CI], 0.35 to 0.66; P<0.001). Symptomatic atrial tachyarrhythmia had recurred in 11.0% of the patients who underwent ablation and in 26.2% of those who received antiarrhythmic drugs (hazard ratio, 0.39; 95% CI, 0.22 to 0.68). The median percentage of time in atrial fibrillation was 0% (interquartile range, 0 to 0.08) with ablation and 0.13% (interquartile range, 0 to 1.60) with antiarrhythmic drugs. Serious adverse events occurred in 5 patients (3.2%) who underwent ablation and in 6 patients (4.0%) who received antiarrhythmic drugs. CONCLUSIONS: Among patients receiving initial treatment for symptomatic, paroxysmal atrial fibrillation, there was a significantly lower rate of atrial fibrillation recurrence with catheter cryoballoon ablation than with antiarrhythmic drug therapy, as assessed by continuous cardiac rhythm monitoring. (Funded by the Cardiac Arrhythmia Network of Canada and others; EARLY-AF ClinicalTrials.gov number, NCT02825979.).

Representation of obesity in contemporary atrial fibrillation ablation randomized controlled trials.

BACKGROUND: The prevalence and impact of obesity on outcomes of atrial fibrillation (AF) ablation randomized controlled trials (RCTs) have not been well studied. OBJECTIVE: To examine the proportion of participants with obesity enrolled in RCTs of AF ablation and outcomes of ablation when subgroup analysis of participants with obesity were available. METHODS: We systematically searched PubMed and EMBASE for AF ablation RCTs published between January 1, 2015 to May 31, 2022. When body mass index (BMI) data were available, normal distribution was assumed and a z score was used to estimate the proportion of obesity. Results categorized by BMI or body weight status were reviewed. Authors were contacted for additional information. RESULTS: Of 148 eligible RCTs with 30174 participants, 144 (97.30%) RCTs did not report the proportion of participants with obesity, while published information regarding BMI was available in 63.51%. Three trials excluded patients based on BMI. Using reported BMI, we estimated the proportion of participants with obesity varied greatly across these trials, ranging from 5.82%-71.9% (median 38.02%, interquartile 29.64%, 49.10%). Patients with obesity were represented in a greater proportion among trials conducted in North America (50.23%) and Asia (44.72%), compared to others (32.16%), p < .001. Subgroup analysis or analysis adjusting for BMI was reported in only 13 (8.78%) RCTs; four (30.77%) of these suggested that BMI or body weight might negatively affect primary outcomes. CONCLUSION: Obesity is a common comorbidity among AF patients. However, most AF ablation RCTs underreported the proportion of participants with obesity and its impact on the primary outcomes.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation.

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Longer and better lives for patients with atrial fibrillation: the 9th AFNET/EHRA consensus conference.

AIMS: Recent trial data demonstrate beneficial effects of active rhythm management in patients with atrial fibrillation (AF) and support the concept that a low arrhythmia burden is associated with a low risk of AF-related complications. The aim of this document is to summarize the key outcomes of the 9th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA). METHODS AND RESULTS: Eighty-three international experts met in Münster for 2 days in September 2023. Key findings are as follows: (i) Active rhythm management should be part of the default initial treatment for all suitable patients with AF. (ii) Patients with device-detected AF have a low burden of AF and a low risk of stroke. Anticoagulation prevents some strokes and also increases major but non-lethal bleeding. (iii) More research is needed to improve stroke risk prediction in patients with AF, especially in those with a low AF burden. Biomolecules, genetics, and imaging can support this. (iv) The presence of AF should trigger systematic workup and comprehensive treatment of concomitant cardiovascular conditions. (v) Machine learning algorithms have been used to improve detection or likely development of AF. Cooperation between clinicians and data scientists is needed to leverage the potential of data science applications for patients with AF. CONCLUSIONS: Patients with AF and a low arrhythmia burden have a lower risk of stroke and other cardiovascular events than those with a high arrhythmia burden. Combining active rhythm control, anticoagulation, rate control, and therapy of concomitant cardiovascular conditions can improve the lives of patients with AF.

A danish healthcare-focused economic evaluation of first-line cryoballoon ablation versus antiarrhythmic drug therapy for the treatment of paroxysmal atrial fibrillation.

INTRODUCTION: Three randomised controlled trials (RCTs) have demonstrated that first-line cryoballoon pulmonary vein isolation decreases atrial tachycardia in patients with symptomatic paroxysmal atrial fibrillation (PAF) compared with antiarrhythmic drugs (AADs). The aim of this study was to develop a cost-effectiveness model (CEM) for first-line cryoablation compared with first-line AADs for the treatment of PAF. The model used a Danish healthcare perspective. METHODS: Individual patient-level data from the Cryo-FIRST, STOP AF and EARLY-AF RCTs were used to parameterise the CEM. The model structure consisted of a hybrid decision tree (one-year time horizon) and a Markov model (40-year time horizon, with a three-month cycle length). Health-related quality of life was expressed in quality-adjusted life years (QALYs). Costs and benefits were discounted at 3% per year. Model outcomes were produced using probabilistic sensitivity analysis. RESULTS: First-line cryoablation is dominant, meaning it results in lower costs (-€2,663) and more QALYs (0.18) when compared to first-line AADs. First-line cryoablation also has a 99.96% probability of being cost-effective, at a cost-effectiveness threshold of €23,200 per QALY gained. Regardless of initial treatment, patients were expected to receive ∼ 1.2 ablation procedures over a lifetime horizon. CONCLUSION: First-line cryoablation is both more effective and less costly (i.e. dominant), when compared with AADs for patients with symptomatic PAF in a Danish healthcare system.

Opioid Use and the Risk of Ventricular Arrhythmias: A Systematic Review and Meta-Analysis.

BACKGROUND: The association between opioid use and the risk of ventricular arrhythmias (VA) is poorly understood. AIMS: The objective of this study was to synthesize the evidence on the risk of VA associated with opioid use. MATERIALS & METHODS: We systematically searched the Cochrane Library, Embase, MEDLINE, and CINAHL databases in July 2022. Risk of bias was assessed using the Cochrane risk for bias tool for randomized controlled trials (RCTs) and ROBINS-I for observational studies. Certainty of evidence was assessed using GRADE. RESULTS: We included 15 studies (12 observational, 2 post hoc analyses of RCTs, 1 RCT). Most studies focused on opioid use for maintenance therapy (n = 9), comparing methadone to buprenorphine (n = 13), and reported QTc prolongation (n = 13). Six observational studies had a critical risk of bias, and one RCT was at high risk of bias. Two studies could not be included in the meta-analysis as they reported a different outcome and studied an opioid antagonist. Meta-analysis of 13 studies indicated that the use of methadone was associated with an increased risk of VA compared to the use of buprenorphine, morphine, placebo, or levacetylmethadol (risk ratio [RR], 2.39; 95% CI, 1.31-4.35; I2 = 60%). The pooled estimate varied greatly between observational studies (RR, 2.12; 95% CI, 1.15-3.91; I2 = 62%) and RCTs (RR, 14.09; 95% CI, 1.52-130.61; I2 = 0%), but both indicated an increased risk. CONCLUSION: In this systematic review and meta-analysis, we found that methadone use is associated with more than twice the risk of VA compared to comparators. However, our findings should be interpreted cautiously given the limited quality of the available evidence.

Adherence to direct or vitamin K antagonist oral anticoagulants in patients with atrial fibrillation: a long-term observational study.

Our objectives were to measure long-term adherence to oral anticoagulants (OACs) in patients with atrial fibrillation (AF) and to identify patient factors associated with adherence. Using linked, population-based administrative data from British Columbia, Canada, an incident cohort of adults prescribed OACs for AF was identified. We calculated the proportion of days covered (PDC) as a time-dependent covariate for each 90-day window from OAC initiation until the end of follow-up. Associations between patient attributes and adherence were assessed using generalized mixed effect linear regression models. 30,264 patients were included. Mean PDC was 0.69 (SD 0.28) over a median follow-up of 6.7 years. 54% of patients were non-adherent (PDC < 0.8). After controlling for confounders, factors positively associated with adherence were number of drug class switches, history of stroke or transient ischemic attack, history of vascular disease, time since initiation, and age. Age > 75 years at initiation, polypharmacy (among VKA users only), and receiving DOAC (vs. VKA) were negatively associated with adherence. PDC decreased over time for VKA users and increased for DOAC users. Over half of AF patients studied were, on average, nonadherent to OAC therapy and missed 32% of their doses. Several patient factors were associated with higher or lower adherence, and adherence to VKA declined during therapy while DOAC adherence increased slightly over time. To min im ize the risk stroke, adherence-supporting interventions are needed for all patients with AF, particularly those aged > 75 years, those with prior stroke or vascular disease, VKA users with polypharmacy, and DOAC recipients.

Healthcare utilization and quality of life for atrial fibrillation burden: the CIRCA-DOSE study.

AIMS: Atrial tachyarrhythmia recurrence ≥30 s remains the primary endpoint of clinical trials; however, this definition has not been correlated with clinical outcomes or pathophysiological processes. This study sought to determine the atrial tachyarrhythmia duration and burden associated with meaningful clinical outcomes. METHODS AND RESULTS: The time and duration of every atrial tachyarrhythmia episode recorded on implantable cardiac monitor were evaluated. Healthcare utilization and quality of life in the year following ablation were prospectively collected. Three hundred and forty-six patients provided 126 110 monitoring days. One-year freedom from recurrence increased with arrhythmia duration thresholds, from 52.6 (182/346) to 93.3% (323/346; P < 0.0001). Patients with atrial fibrillation (AF) recurrence limited to durations ≤1 h had rates of healthcare utilization comparable with patients free of recurrence, while patients with AF recurrences lasting >1 h had a relative risk for emergency department consultation of 3.2 [95% confidence interval (CI) 2.0-5.3], hospitalization of 5.3 (95% CI 2.9-9.6), and repeat ablation of 27.1 (95% CI 10.5-71.0). Patients with AF burden of ≤0.1% had rates of healthcare utilization comparable with patients free of recurrence, while patients with AF burden of >0.1% had a relative risk for emergency department consultation of 2.4 (95% CI 1.9-3.9), hospitalization of 6.8 (95% CI 3.6-13.0), cardioversion of 9.1 (95% CI 3.3-25.6), and repeat ablation of 21.8 (95% CI 9.2-52.2). Compared with patients free of recurrence, the disease-specific quality of life was significantly impaired with AF episode durations >24 h, or AF burdens >0.1%. CONCLUSION: AF recurrence, as defined by 30 s of arrhythmia, lacks clinical relevance. AF episode durations >1 h or burdens >0.1% were associated with increased rates of healthcare utilization.

Influence of Monitoring Strategy on Assessment of Ablation Success and Postablation Atrial Fibrillation Burden Assessment: Implications for Practice and Clinical Trial Design.

BACKGROUND: Various noninvasive intermittent rhythm monitoring strategies have been used to assess arrhythmia recurrences in trials evaluating pharmacological and invasive therapeutic interventions for atrial fibrillation (AF). We determined whether a frequency and duration of noninvasive rhythm monitoring could be identified that accurately detects arrhythmia recurrences and approximates the AF burden derived from continuous monitoring using an implantable cardiac monitor (ICM). METHODS: The rhythm history of 346 patients enrolled in the CIRCA-DOSE trial (Cryoballoon Versus Contact-Force Irrigated Radiofrequency Catheter Ablation) was reconstructed. Using computer simulations, we evaluated event-free survival, sensitivity, negative predictive value, and AF burden of a range of noninvasive monitoring strategies, including those used in contemporary AF ablation trials. RESULTS: A total of 126 290 monitoring days were included in the analysis. At 12 months, 164 patients experienced atrial arrhythmia recurrence as documented by the ICM (1-year event-free survival, 52.6%). Most noninvasive monitoring strategies used in AF ablation trials had poor sensitivity for detecting arrhythmia recurrence. Sensitivity increased with the intensity of monitoring, with serial (3) short-duration monitors (24-/48-hour ECG monitors) missing a substantial proportion of recurrences (sensitivity, 15.8% [95% CI, 8.9%-20.7%] and 24.5% [95% CI, 16.2%-30.6%], respectively). Serial (3) longer-term monitors (14-day ECG monitors) more closely approximated the gold standard ICM (sensitivity, 64.6% [95% CI, 53.6%-74.3%]). AF burden derived from short-duration monitors significantly overestimated the true AF burden in patients with recurrences. Increasing monitoring duration resulted in improved correlation and concordance between noninvasive estimates of the invasive AF burden (R2 = 0.85 and interclass correlation coefficient = 0.91 for serial [3] 14-day ECG monitors versus ICM). CONCLUSIONS: The observed rate of postablation atrial tachyarrhythmia recurrence is highly dependent on the arrhythmia monitoring strategy employed. Between-trial discrepancies in outcomes may reflect different monitoring protocols. On the basis of measures of agreement, serial long-term (7-14 day) intermittent monitors accumulating at least 28 days of annual monitoring provide estimates of AF burden comparable with ICM. However, ICMs outperform intermittent monitoring for arrhythmia detection, and should be considered the gold standard for clinical trials. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01913522.

DREAM-ICD-II Study.

BACKGROUND: Regulatory authorities of most industrialized countries recommend 6 months of private driving restriction after implantation of a secondary prevention implantable cardioverter-defibrillator (ICD). These driving restrictions result in significant inconvenience and social implications. This study aimed to assess the incidence rate of appropriate device therapies in contemporary recipients of a secondary prevention ICD. METHODS: This retrospective study at 3 Canadian tertiary care centers enrolled consecutive patients with new secondary prevention ICD implants between 2016 and 2020. RESULTS: For a median of 760 days (324, 1190 days), 721 patients were followed up. The risk of recurrent ventricular arrhythmia was highest during the first 3 months after device insertion (34.4%) and decreased over time (10.6% between 3 and 6 months, 11.7% between 6 and 12 months). The corresponding incidence rate per 100 patient-days was 0.48 (95% CI, 0.35-0.64) at 90 days, 0.28 (95% CI, 0.17-0.45) at 180 days, and 0.21 (95% CI, 0.13-0.33) between 181 and 365 days after ICD insertion (P<0.001). The cumulative incidence of arrhythmic syncope resulting in sudden cardiac incapacitation was 1.8% within the first 90 days and subsequently dropped to 0.4% between 91 and 180 days (P<0.001) after ICD insertion. CONCLUSIONS: The incidence rate of appropriate therapies resulting in sudden cardiac incapacitation in contemporary recipients of a secondary prevention ICD is much lower than previously reported and declines significantly after the first 3 months. Lowering driving restrictions to 3 months after the index cardiac event seems safe, and revision of existing guidelines should be considered in countries still adhering to a 6-month period. Existing restrictions for private driving after implantation of a secondary prevention ICD should be reconsidered.

Progress in atrial fibrillation ablation during 25 years of Europace journal.

The first edition of Europace journal in 1999 came right around the time of the landmark publication of the electrophysiologists from Bordeaux, establishing how elimination of ectopic activity from the pulmonary veins (PVs) resulted in a marked reduction of atrial fibrillation (AF). The past 25 years have seen an incredible surge in scientific interest to develop new catheters and energy sources to optimize durability and safety of ablation, as well as study the mechanisms for AF and devise ablation strategies. While ablation in the beginning was performed with classic 4 mm tip catheters that emitted radiofrequency (RF) energy to create tissue lesions, this evolved to using irrigation and contact force (CF) measurement while increasing power. Also, so-called single-shot devices were developed with balloons and arrays to create larger contiguous lesions, and energy sources changed from RF current to cryogenic ablation and more recently pulsed field ablation with electrical current. Although PV ablation has remained the basis for every AF ablation, it was soon recognized that this was not enough to cure all patients, especially those with non-paroxysmal AF. Standardized approaches for additional ablation targets have been used but have not been satisfactory in all patients so far. This led to highly technical mapping systems that are meant to unravel the drivers for the maintenance of AF. In the following sections, the development of energies, strategies, and tools is described with a focus on the contribution of Europace to publish the outcomes of studies that were done during the past 25 years.

Same-day discharge for atrial fibrillation ablation: outcomes and impact of ablation modality.

AIMS: Same-day discharge is increasingly common after catheter ablation for atrial fibrillation (AF). However, the impact of same-day discharge on healthcare utilization after ablation and whether this differs by ablation modality remains uncertain. We examined the safety, efficacy, and subsequent healthcare utilization of a same-day discharge protocol for AF ablation, including radiofrequency (RF) and cryoballoon ablation, in a contemporary cohort. METHODS AND RESULTS: All consecutive patients for whom full healthcare utilization data were available at two centres and who underwent AF ablation from 2018 to 2019 were included. Same-day discharge was the default strategy for all patients. The efficacy and safety outcomes were proportions of same-day discharge and readmission/emergency room (ER) visits, and post-discharge complications, respectively. Of the 421 patients who underwent AF ablation (mean 63.3 ± 10.2 years, 33% female), 90.5% (381/421) achieved same-day discharge with no difference between RF and cryoballoon ablation (89.8 vs. 95.1%, adjusted P = 0.327). Readmission ≤30 days occurred in 4.8%, with ER visits ≤30 days seen in 26.1% with no difference between ablation modalities (P = 0.634). Patients admitted overnight were more likely to present to the ER (40.0 vs. 24.7% with same-day discharge, P = 0.036). The overall post-discharge complication rate was low at 4/421 (1.0%), with no difference between ablation modality (P = 0.324) and admission/same-day discharge (P = 0.485). CONCLUSION: Same-day discharge can be achieved in a majority of patients undergoing RF or cryoballoon ablation for AF. Healthcare utilization, particularly ER visits, remains high after AF ablation, regardless of ablation modality or same-day discharge.

Kidney function monitoring and trajectories in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) and chronic kidney disease (CKD) frequently co-exist. The frequency of kidney monitoring and range of kidney function in patients with AF in clinical practice are uncertain. METHODS: All adult Albertans with AF between 2008 and 2017 were identified using ICD-9 and -10 codes 427.3 and I48. Kidney Disease Improving Global Outcomes (KDIGO) risk categories were defined using eGFR by the Chronic Kidney Disease Epidemiology Collaborative equation and albuminuria results within 6 months of eGFR measurement. eGFR trajectories were compared from baseline to maximum value within the following year. RESULTS: Among 105,946 patients with AF, 16.0% were KDIGO category G1 (eGFR ≥ 90), 49.0% G2 (60-89.9), 19.8% G3a (45-59.9), 11.4% G3b (30-44.9), and G4 3.8% (15-29.9). Albuminuria was normal/mild 83.4%, moderate 11.7%, and severe 4.9%. Kidney monitoring was more common among people with lower eGFR and worse albuminuria, from approximately twice annually for G1-2/A1-2 to 8 times annually in stage G4A3. Approximately 60-80% of patients received guideline-recommended monitoring, consistent across KDIGO stages. With lower baseline eGFR, annual change in eGFR decreased while the relative proportion of patients who worsened compared to improved increased: for baseline eGFR 60-89.9, 16.7% worsened vs 6.7% improved, but for eGFR 30-44.9, 8.8% worsened but only 1.0% improved. CONCLUSION: The frequency of kidney function monitoring in patients with AF increased with worsening KDIGO risk category and adhered to KDIGO guidelines in approximately three quarters of patients. A minority of patients had moderate to severe eGFR impairment, of whom most remained stable over 1 year.

Approach to atrial fibrillation: Essentials for primary care.

OBJECTIVE: To support family physicians in preventing atrial fibrillation (AF) in patients at risk and in identifying and managing those with established AF; and to summarize key recommendations for ideal screening and care of patients. SOURCES OF INFORMATION: The 2020 Canadian Cardiovascular Society and Canadian Heart Rhythm Society comprehensive guidelines for the management of AF, based on current evidence and clinical experience related to AF. MAIN MESSAGE: Atrial fibrillation, which is estimated to affect at least 500,000 Canadians, is associated with high risks of stroke, heart failure, and death. Primary care clinicians occupy a central role in the management of this chronic condition, focusing on the challenges of preventing AF and identifying, diagnosing, treating, and following patients with AF. Evidence-based guidelines that provide optimal management strategies have been published by the Canadian Cardiovascular Society and Canadian Heart Rhythm Society to assist in these tasks. Messages critical to primary care are offered to support effective knowledge translation. CONCLUSION: Most patients with AF can be managed effectively in primary care. Family physicians not only play an important role in ensuring patients with AF receive timely diagnoses, but they are also key to providing initial and ongoing care, especially in patients with comorbid conditions.

The Random Effects Warfarin Days' Supply (REWarDS) Model: Development and Validation of a Novel Method for Estimating Exposure to Warfarin Using Administrative Data.

Warfarin's complex dosing is a significant barrier to measurement of its exposure in observational studies using population databases. Using population-based administrative data (1996-2019) from British Columbia, Canada, we developed a method based on statistical modeling (Random Effects Warfarin Days' Supply (REWarDS)) that involves fitting a random-effects linear regression model to patients' cumulative dosage over time for estimation of warfarin exposure. Model parameters included a minimal universally available set of variables from prescription records for estimation of patients' individualized average daily doses of warfarin. REWarDS estimates were validated against a reference standard (manual calculation of the daily dose using the free-text administration instructions entered by the dispensing pharmacist) and compared with alternative methods (fixed window, fixed tablet, defined daily dose, and reverse wait time distribution) using Pearson's correlation coefficient (r), the intraclass correlation coefficient, and the root mean squared error. REWarDS-estimated days' supply showed strong correlation and agreement with the reference standard (r = 0.90 (95% confidence interval (CI): 0.90, 0.90); intraclass correlation coefficient = 0.95 (95% CI: 0.94, 0.95); root mean squared error = 8.24 days) and performed better than all of the alternative methods. REWarDS-estimated days' supply was valid and more accurate than estimates from all other available methods. REWarDS is expected to confer optimal precision in studies measuring warfarin exposure using administrative data.

Characterization of arrhythmia substrate to ablate persistent atrial fibrillation (COAST-AF): Randomized controlled trial design and rationale.

BACKGROUND: Atrial low voltage area (LVA) catheter ablation has emerged as a promising strategy for ablation of persistent atrial fibrillation (AF). It is unclear if catheter ablation of atrial LVA increases treatment success rates in patients with persistent AF. OBJECTIVE: The primary aim of this trial is to assess the potential benefit of adjunctive catheter ablation of atrial LVA in addition to pulmonary vein isolation (PVI) in patients with persistent AF, when compared to PVI alone. The secondary aims are to evaluate safety outcomes, the quality of life and the healthcare resource utilization. METHODS/DESIGN: A multicenter, prospective, parallel-group, 2-arm, single-blinded randomized controlled trial is under way (NCT03347227). Patients who are candidates for catheter ablation for persistent AF will be randomly assigned (1:1) to either PVI alone or PVI + atrial LVA ablation. The primary outcome is 18-month documented event rate of atrial arrhythmia (AF, atrial tachycardia or atrial flutter) post catheter ablation. Secondary outcomes include procedure-related complications, freedom from atrial arrhythmia at 12 months, AF burden, need for emergency department visits/hospitalization, need for repeat ablation for atrial arrhythmia, quality of life at 12 and 18 months, ablation time, and procedure duration. DISCUSSION: Characterization of Arrhythmia Mechanism to Ablate Atrial Fibrillation (COAST-AF) is a multicenter randomized trial evaluating ablation strategies for catheter ablation. We hypothesize that catheter ablation of atrial LVA in addition to PVI will result in higher procedural success rates when compared to PVI alone in patients with persistent AF.

Bayesian network meta-analysis comparing cryoablation, radiofrequency ablation, and antiarrhythmic drugs as initial therapies for atrial fibrillation.

BACKGROUND: Antiarrhythmic drugs (AADs) and catheter ablation are first line treatments of paroxysmal atrial fibrillation (PAF), however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus AADs as an early rhythm strategy. OBJECTIVE: To assess the safety and efficacy of cryoablation versus radiofrequency ablation (RFA) versus AADs as a first line therapy of PAF. METHODS: MEDLINE, Embase, Scopus and CENTRAL were searched to retrieve randomized clinical trials (RCTs) comparing cryoablation, RFA or AADs to one another as first line therapies for atrial fibrillation (AF). The primary outcome was overall freedom from arrhythmia recurrence (AF, atrial flutter [AFL], atrial tachycardia). Secondary outcomes included freedom from symptomatic arrhythmia recurrence, hospitalization, and serious adverse events. A random-effects Bayesian network meta-analysis was used to calculate odds ratios (OR) and 95% credible intervals (CrI). RESULTS: Six RCTs (N = 1212) met the inclusion criteria (605 AADs, 365 Cryoablation, and 245 RFA). Compared with AADs, overall recurrence was reduced with RFA (OR: 0.31; 95% CrI: 0.10-0.71) and cryoablation (OR: 0.39; 95% CrI: 0.16-1.00). Comparing ablation (cryoablation and RFA) with AADs in respect to freedom from symptomatic AF recurrence, neither cryoablation (OR: 0.35; 95% CrI: 0.06-1.96) nor RFA (OR: 0.34; 95% CrI: 0.07-1.27) resulted in statistically significant reductions individually compared to AADs, though pooled ablation with both technologies showed lower odds of arrhythmia recurrence (OR: 0.35; 95% CrI: 0.13-0.79). In terms of serious adverse events rates, neither cryoablation (OR: 0.77; 95% CrI: 0.44-1.39) nor RFA (OR: 1.45; 95% CrI: 0.67-3.23) were significantly different to AADs. RFA resulted in a statistically significant reduction in hospitalizations compared to AAD (OR: 0.08; 95% CrI: 0.01-0.99), whereas cryoablation did not (OR: 0.77; 95% CrI: 0.44-1.39). The surface under the cumulative ranking curve showed RFA to be the most effective treatment at reducing overall rates of recurrence, symptomatic recurrence and hospitalizations; whereas cryoablation was most likely to reduce serious adverse events. CONCLUSION: Cryoablation and RFA are both effective and safe first line therapies for AF compared to AADs, with RFA being the most effective at reducing recurrences.