Patient characteristics, predictors and outcome of pacemaker patients upgraded to an implantable cardioverter defibrillator.

AIMS: Pacemaker (PM) patients may require a subsequent upgrade to an implantable cardioverter defibrillator (ICD). Limited data exists on this patient population. We sought to characterize this population, to assess predictors for ICD upgrade, and to report the outcome. METHODS: From our prospective PM and ICD implantation registry, all patients who underwent PM and/or ICD implantations at our center were analyzed. Patient characteristics and outcomes of PM patients with subsequent ICD upgrade were compared to age- and sex-matched patients with de novo ICD implantation, and to PM patients without subsequent upgrade. RESULTS: Of 1'301 ICD implantations, 60 (5%) were upgraded from PMs. Median time from PM implantation to ICD upgrade was 2.6 years (IQR 1.3-5.4). Of 2'195 PM patients, 28 patients underwent subsequent ICD upgrades, corresponding to an estimated annual incidence of an ICD upgrade of at least 0.33%. Lower LVEF (p = .05) and male sex (p = .038) were independent predictors for ICD upgrade. Survival without death, transplant and LVAD implantation were worse both for upgraded ICD patients compared to matched patients with de novo ICD implantation (p = .05), as well as for PM patients with subsequent upgrade compared to matched PM patients not requiring an upgrade (p = .036). CONCLUSIONS: One of 20 ICD implantations are upgrade of patients with a PM. At least one of 30 PM patients will require an ICD upgrade in the following 10 years. Predictors for ICD upgrade are male sex and lower LVEF at PM implantation. Upgraded patients have worse outcomes.

A Direct-Digital 40 µA 100 kb/s Intracardiac Communication Receiver with 250 µs Startup Time for Low Duty-Cycle Leadless Pacemaker Synchronization.

The first commercial dual-chamber leadless pacemaker (LLPM) was introduced recently. The system combines two separate implants situated in the right atrium and the right ventricle of the heart. Implant synchronization is accomplished with conductive intracardiac communication (CIC) using the myocardium and blood as transmission channel. Successful implant synchronization of this dual-chamber LLPM has been demonstrated. However, the continuously active synchronization transceivers, consuming about 800 nA, cause a 25-45% reduction in the projected device longevity. This work proposes an alternative strategy for power-optimized LLPM synchronization, which is based on synchronous duty-cycling of the transceivers and direct-digital CIC (DD-CIC). In line with this strategy, a novel low-power DD-CIC receiver for short-packet communication based on Manchester-encoded data and with fast startup time is presented. The circuit was fabricated in 180 nm CMOS technology and analyzed with respect to sensitivity, current consumption and startup time under highly duty-cycled operation. The receiver achieves a sensitivity of 81.6±7.4 µV at a data rate of 100 kb/s, with an active current consumption of 39.1±0.6 µA and a startup time below 250 µs. Operating the receiver as specified by the proposed LLPM synchronization strategy reduces the current consumption to a measured average value of 73 nA. In conclusion, this work suggests synchronous duty-cycling for CIC-based implant synchronization as a promising concept to severely reduce the current consumption of contemporary dual-chamber LLPMs. Consequently, device longevity may be increased significantly, potentially reducing the frequency of costly and complication-prone re-interventions.

Durability of CLOSE-Guided Pulmonary Vein Isolation in Persistent Atrial Fibrillation: A Prospective Remapping Study.

BACKGROUND: Recurrence of paroxysmal atrial fibrillation (AF) following pulmonary vein isolation (PVI) is presumably caused by pulmonary vein (PV) reconnections. However, there is little data available on the durability of PVI and incidence of arrhythmia recurrence in patients with persistent AF. OBJECTIVES: To evaluate the lesion durability by means of an a priori planned remapping procedure in patients with persistent AF undergoing CLOSE-guided PVI. METHODS: In a prospective study, we included patients with symptomatic, persistent AF undergoing CLOSE-guided radiofrequency ablation. Irrespective of AF recurrence, a redo procedure was mandated 6 months following the index procedure to evaluate PV reconnections. The outcome of AF ablation was based on clinical recurrence and 7-day Holter electrocardiogram 3 and 6 months after the index procedure and 3, 6, and 12 months after the redo procedure. RESULTS: Of 30 patients included, 26 (81% men; median age 68 years) underwent the planned remapping study a median of 6 months after the index procedure, whereas 4 patients without recurrence refused a repeat procedure. In total, 78 of 102 (76%) PVs showed durable isolation and 15 patients (58%) presented complete isolation of all PVs. Beyond the blanking period, 6 of 26 patients (23%) had arrhythmia recurrence before the redo procedure. Recurrence had occurred in 33% of patients with complete isolation of all veins and in 9% of patients with PV reconnections (P = 0.197). After re-PVI in patients with PV reconnections and additional ablation in patients with recurrence but durable PVI, 17 of 26 patients (65%) were free of arrhythmia after 12 months. CONCLUSIONS: In patients with persistent AF, CLOSE-guided PVI resulted in durable rate of PVI on a per-vein and per-patient level of 76% and 58%, respectively. Arrhythmia recurrence was numerically higher in patients with durable PVI compared with patients without.

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 (HRS), the Asia Pacific HRS, and the Latin American HRS.

Impact of atrial fibrillation phenotype and left atrial volume on outcome after pulmonary vein isolation.

AIMS: Pulmonary vein isolation (PVI) is increasingly performed in patients with atrial fibrillation (AF). Both AF phenotype and left atrial (LA) volume have been shown to influence ablation outcome. The inter-relationship of the two is incompletely understood. We aimed to investigate the impact of AF phenotype vs. LA volume on outcome after PVI. METHODS AND RESULTS: In a retrospective analysis of a prospective registry of patients undergoing a first PVI, the association of AF phenotype and LA volume index (LAVI) was assessed as well as their impact on AF recurrence during follow-up. Overall, 476 patients were enrolled (median age 63 years, 29% females, 65.8% paroxysmal AF). Obesity, hypertension, chronic kidney disease, and heart failure were all significantly more frequent in persistent AF. After 1 year, single-procedure, freedom from arrhythmia recurrence was 61.5%. Patients with paroxysmal AF had better outcomes compared with patients with persistent AF (65.6 vs. 52.7%, P = 0.003), as had patients with no/mild vs. moderate/severe LA dilation (LAVI <42 mL/m2 67.1% vs. LAVI ≥42 mL/m2 53%, P < 0.001). The combination of both parameters refined prediction of 1-year recurrence (P < 0.001). After adjustment for additional clinical risk factors in multivariable Cox proportional hazard analysis, both AF phenotype and LAVI ≥42 mL/m2 contributed significantly towards the prediction of 1-year recurrence. CONCLUSION: Atrial fibrillation phenotype and LA volume are independent predictors of outcome after PVI. Persistent AF with no/mild LA dilation has a similar risk of recurrence as paroxysmal AF with a moderate/severe LA dilation and should be given similar priority for ablation.

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 .

Risk of Cardiac Arrhythmias Among Climbers on Mount Everest.

Importance: Arterial hypoxemia, electrolyte imbalances, and periodic breathing increase the vulnerability to cardiac arrhythmia at altitude. Objective: To explore the incidence of tachyarrhythmias and bradyarrhythmias in healthy individuals at high altitudes. Design, Setting, and Participants: This prospective cohort study involved healthy individuals at altitude (8849 m) on Mount Everest, Nepal. Recruitment occurred from January 25 to May 9, 2023, and data analysis took place from June to July 2023. Exposure: All study participants underwent 12-lead electrocardiogram, transthoracic echocardiography, and exercise stress testing before and ambulatory rhythm recording both before and during the expedition. Main Outcome: The incidence of a composite of supraventricular (>30 seconds) and ventricular (>3 beats) tachyarrhythmia and bradyarrhythmia (sinoatrial arrest, second- or third-degree atrioventricular block). Results: Of the 41 individuals recruited, 100% were male, and the mean (SD) age was 33.6 (8.9) years. On baseline investigations, there were no signs of exertional ischemia, wall motion abnormality, or cardiac arrhythmia in any of the participants. Among 34 individuals reaching basecamp at 5300 m, 32 participants climbed to 7900 m or higher, and 14 reached the summit of Mount Everest. A total of 45 primary end point-relevant events were recorded in 13 individuals (38.2%). Forty-three bradyarrhythmic events were documented in 13 individuals (38.2%) and 2 ventricular tachycardias in 2 individuals (5.9%). Nine arrhythmias (20%) in 5 participants occurred when climbers were using supplemental bottled oxygen, whereas 36 events (80%) in 11 participants occurred at lower altitudes when no supplemental bottled oxygen was used. The proportion of individuals with arrhythmia remained stable across levels of increasing altitude, while event rates per 24 hours numerically increased between 5300 m (0.16 per 24 hours) and 7300 m (0.37 per 24 hours) before decreasing again at higher altitudes, where supplemental oxygen was used. None of the study participants reported dizziness or syncope. Conclusion and Relevance: In this study, more than 1 in 3 healthy individuals experienced cardiac arrhythmia during the climb of Mount Everest, thereby confirming the association between exposure to high altitude and incidence of cardiac arrhythmia. Future studies should explore the potential implications of these rhythm disturbances.

Pulsed-field vs cryoballoon vs radiofrequency ablation: Outcomes after pulmonary vein isolation in patients with persistent atrial fibrillation.

BACKGROUND: Pulsed-field ablation (PFA) has shown promising data in terms of safety and procedural efficiency for pulmonary vein isolation (PVI), with similar long-term outcomes compared to radiofrequency ablation (RFA) and cryoballoon ablation (CBA) in patients with paroxysmal atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to compare the procedural and long-term outcomes in patients with persistent AF undergoing PVI using PFA, CBA, or RFA. METHODS: Consecutive patients with persistent AF undergoing first PVI with PFA, CBA, or RFA were included. Patients underwent 7-day Holter electrocardiography at 3, 6, and 12 months postablation. The primary outcome was recurrence of any atrial arrhythmia after a 90-day blanking period. Safety outcomes included the composite of in-hospital major adverse events. RESULTS: A total of 533 patients with persistent AF underwent PVI using PFA (n = 214), CBA (n = 190), or RFA (n = 129). Procedures with PFA guided by fluoroscopy were shorter than those with CBA (median 60 minutes; interquartile range [IQR] 53-80 minutes vs 84 minutes; IQR 68-101 minutes; P ≤ .001), and procedures with PFA in combination with 3-dimensional electroanatomic mapping were shorter than those with RFA (median 101 minutes; IQR 85-126 minutes vs 171 minutes; IQR 141-204 minutes; P < .001). Acute safety events occurred in 2.3%, 2.6%, and 0.8% in the PFA, CBA, and RFA groups, respectively (P = .545). The 1-year confounder-adjusted estimate for freedom from atrial arrhythmias was 62.1% for CBA, 55.3% for PFA, and 48.3% for RFA (CBA vs PFA: P = .79; CBA vs RFA: P = .009; PFA vs RFA: P = .010). CONCLUSION: In patients with persistent AF undergoing first PVI, 1-year confounder-adjusted outcomes are better with PFA and CBA than with RFA.

Strategies to improve atrioventricular synchrony in patients with a Micra AV leadless pacemaker.

The second generation of transcatheter pacing systems, called Micra AV, can provide atrioventricular (AV) synchronous pacing via a new pacing algorithm relying on sensing mechanical atrial contraction. Several novel programming parameters were introduced to enable AV synchronous pacing, including an A3 window and A4 window as well as a conduction mode switch and an activity mode switch. In addition to several automated features, manual programming optimization of some of the novel parameters is key to improving AV synchrony. A solid knowledge of the features and their programming is essential for electrophysiologists implanting or following patients with Micra AV devices. Differences in programming optimization might partially explain the high variability of AV synchrony published in real-world data reports. This article reviews the key programming parameters of Micra AV. Subsequently, optimal programming recommendations for defined patient profiles are presented. Those were established by consensus within an expert panel comprised of 11 European electrophysiologists from high-volume Micra AV centres. The patient profiles were (1) high degree AV block and slow sinus rhythm; (2) high degree AV block and fast sinus rhythm; and (3) intermittent AV block. The panel recommended to evaluate the mechanical atrial activity on transthoracic echocardiography prior to implant. It was also agreed that Auto A3 Threshold and Tracking Check should be turned off in all patients, AV conduction mode switch should be turned off in all patients with high degree AV block, and the lower rate should be programmed to 50 bpm with exceptions based on individual clinical assessment. Future studies will be useful to evaluate the strength of those recommendations to improve the AV synchrony.

Impact of Left Atrial Posterior Wall Ablation During Pulsed-Field Ablation for Persistent Atrial Fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) alone is insufficient to treat many patients with persistent atrial fibrillation (PersAF). Adjunctive left atrial posterior wall (LAPW) ablation with thermal technologies has revealed lack of efficacy, perhaps limited by the difficulty in achieving lesion durability amid concerns of esophageal injury. OBJECTIVES: This study aims to compare the safety and effectiveness of PVI + LAPW ablation vs PVI in patients with PersAF using pulsed-field ablation (PFA). METHODS: In a retrospective analysis of the MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-approval Clinical Use of Pulsed Field Ablation) registry, we studied consecutive PersAF patients undergoing post-approval treatment with a pentaspline PFA catheter. The primary effectiveness outcome was freedom from any atrial arrhythmia of ≥30 seconds. Safety outcomes included the composite of acute and chronic major adverse events. RESULTS: Of the 547 patients with PersAF who underwent PFA, 131 (24%) received adjunctive LAPW ablation. Compared to PVI-alone, patients receiving adjunctive LAPW ablation were younger (65 vs 67 years of age, P = 0.08), had a lower CHA2DS2-VASc score (2.3 ± 1.6 vs 2.6 ± 1.6, P = 0.08), and were more likely to receive electroanatomical mapping (48.1% vs 39.0%, P = 0.07) and intracardiac echocardiography imaging (46.1% vs 17.1%, P < 0.001). The 1-year Kaplan-Meier estimate for freedom from atrial arrhythmias was not statistically different between groups in the full (PVI + LAPW: 66.4%; 95% CI: 57.6%-74.4% vs PVI: 73.1%; 95% CI: 68.5%-77.2%; P = 0.68) and propensity-matched cohorts (PVI + LAPW: 71.7% vs PVI: 68.5%; P = 0.34). There was also no significant difference in major adverse events between the groups (2.2% vs 1.4%, respectively, P = 0.51). CONCLUSIONS: In patients with PersAF undergoing PFA, as compared to PVI-alone, adjunctive LAPW ablation did not improve freedom from atrial arrhythmia at 12 months.

Cryoballoon pulmonary vein isolation as first-line treatment of typical atrial flutter: long-term outcomes of the CRAFT trial.

BACKGROUND: CRAFT was an international, multicentre, randomised controlled trial across 11 sites in the United UK and Switzerland. Given the evidence that pulmonary vein triggers may be responsible for atrial flutter (AFL) as well as atrial fibrillation (AF), we hypothesised that cryoballoon pulmonary vein isolation (PVI) would provide greater symptomatic arrhythmia reduction than cavotricuspid isthmus (CTI) ablation, whilst also reducing the subsequent burden of AF. Twelve-month outcomes were previously reported. In this study, we report the extended outcomes of the CRAFT study to 36 months. METHODS: Patients with typical AFL and no evidence of AF were randomised 1:1 to cryoballoon PVI or radiofrequency CTI. All patients received an implantable loop recorder (ILR) for continuous cardiac rhythm monitoring. The primary outcome was time-to-symptomatic arrhythmia recurrence > 30 s. Secondary outcomes included time-to-first-AF episode ≥ 2 min. The composite safety outcome included death, stroke and procedural complications. RESULTS: A total of 113 patients were randomised to cryoballoon PVI (n = 54) or radiofrequency CTI ablation (n = 59). Ninety-one patients reconsented for extended follow-up beyond 12 months. There was no difference in the primary outcome between arms, with the primary outcome occurring in 12 PVI vs 11 CTI patients (HR 0.97; 95% CI 0.43-2.20; p = 0.994). AF ≥ 2 min was significantly less frequent in the PVI arm, affecting 26 PVI vs 36 CTI patients (HR 0.48; 95% CI 0.29-0.79; p = 0.004). The composite safety outcome occurred in 5 PVI and 6 CTI patients (p = 0.755). CONCLUSION: Cryoballoon PVI shows similar efficacy to radiofrequency CTI ablation in reducing symptomatic arrhythmia recurrence in patients presenting with isolated typical AFL but significantly reduces the occurrence of subsequent AF.

Incidental Arrhythmias During Atrial Fibrillation Screening With Repeat 7-Day Holter ECGs in a Hospital-Based Patient Population.

BACKGROUND: Screening for atrial fibrillation (AF) may reveal incidental arrhythmias of relevance. The aim of this study was to describe incidental arrhythmias detected during screening for AF in the STAR-FIB (Predicting SilenT AtRial FIBrillation in Patients at High Thrombembolic Risk) cohort study. METHODS AND RESULTS: In the STAR-FIB cohort study, we screened hospitalized patients for AF with 3 repeat 7-day Holter ECGs. We analyzed all Holter ECGs for the presence of the following incidental arrhythmias: (1) sinus node dysfunction, defined as sinus pause of ≥3 seconds' duration; (2) second-degree (including Wenckebach) or higher-degree atrioventricular block (AVB); (3) sustained supraventricular tachycardia of ≥30 seconds' duration; and (4) sustained ventricular tachycardia of ≥30 seconds' duration. We furthermore report treatment decisions because of incidental arrhythmias. A total of 2077 Holter ECGs were performed in 794 patients (mean age, 74.7 years; 49% women), resulting in a mean cumulative duration of analyzable ECG signal of 414±136 hours/patient. We found incidental arrhythmias in 94 patients (11.8%). Among these were sinus node dysfunction in 14 patients (1.8%), AVB in 41 (5.2%), supraventricular tachycardia in 42 (5.3%), and ventricular tachycardia in 2 (0.3%). Second-degree AVB was found in 23 patients (2.9%), 2:1 AVB in 10 (1.3%), and complete AVB in 8 (1%). Subsequently, 8 patients underwent pacemaker implantation, 1 for sinus node dysfunction (post-AF conversion pause of 9 seconds) and 7 for advanced AVB. One patient had an implantable cardioverter-defibrillator implanted for syncopal ventricular tachycardia. CONCLUSIONS: Incidental arrhythmias were frequently detected during screening for AF in the STAR-FIB study and resulted in device therapy in 1.1% of our cohort patients.

Durability of Pulmonary Vein Isolation Using Pulsed-Field Ablation: Results From the Multicenter EU-PORIA Registry.

BACKGROUND: Pulsed-field ablation (PFA) is a novel nonthermal ablation technology with high procedural safety and efficiency for pulmonary vein isolation (PVI). Premarket data showed high PVI durability during mandatory remapping studies. Data on lesion durability in real-world patients with clinically indicated redo procedures are scarce. OBJECTIVES: This study sought to report PVI durability rates in patients undergoing a clinically indicated redo procedure after an index PVI using PFA. METHODS: Patients from 7 European centers undergoing an index PVI using PFA were included the EU-PORIA (European Real-world Outcomes With Pulsed Field Ablation in Patients With Symptomatic Atrial Fibrillation) registry. In patients with subsequent left atrial redo procedures due to arrhythmia recurrence, 3-dimensional electroanatomical maps were acquired. PVI durability was assessed on a per-vein and per-patient level, and sites of reconnections and predictors of lesion durability were identified. RESULTS: Of 1,184 patients (62% paroxysmal atrial fibrillation) undergoing an index PVI using PFA, 272 (23%) had an arrhythmia recurrence. Of these, 144 (53%) underwent a left atrial redo procedure a median of 7 (Q1-Q3: 5-10) months after the first ablation. Three-dimensional electroanatomical maps identified 404 of 567 pulmonary veins (71%) with durable isolation. In 54 patients (38%), all pulmonary veins were durably isolated. Prior operator experience with cryoballoon ablation was associated with a higher PVI durability compared to operators with only point-by-point radiofrequency experience (76% vs 60%; P < 0.001). Neither the operators' cumulative experience in atrial fibrillation ablation (≤5 vs >5 years) nor the size of the PFA device used (31 mm vs 35 mm) had an impact on subsequent lesion durability (both P > 0.50). CONCLUSIONS: In 144 patients with arrhythmia recurrence after PFA PVI, durable isolation was observed in 71% of the pulmonary veins during the redo procedure, and 38% of all patients showed durable isolation of all veins.

Long-term outcomes of the pentaspline pulsed-field ablation catheter for the treatment of paroxysmal atrial fibrillation: results of the prospective, multicentre FARA-Freedom Study.

AIMS: Pulmonary vein isolation (PVI) is a well-established strategy for the treatment of paroxysmal atrial fibrillation (PAF). Despite randomized controlled trials and real-world data showing the promise of pulsed-field ablation (PFA) for this treatment, long-term efficacy and safety data demonstrating single-procedure outcomes off antiarrhythmic drugs remain limited. The aim of the FARA-Freedom Study was to evaluate the long-term efficacy and safety of PFA using the pentaspline catheter for PAF. METHODS AND RESULTS: FARA-Freedom, a prospective, non-randomized, multicentre study, enrolled patients with PAF undergoing de novo PVI with PFA, who were followed for 12 months with weekly transtelephonic monitoring and a 72-h Holter ECG at 6 and 12 months. The primary safety endpoint was a composite of device- or procedure-related serious adverse events out to 7 days post-ablation and PV stenosis or atrioesophageal (AE) fistula out to 12 months. Treatment success is a composite of acute PVI and chronic success, which includes freedom from any documented atrial tachyarrhythmia longer than 30 s, use of antiarrhythmic drugs or cardioversion after a 3-month blanking period, or use of amiodarone or repeat ablation at any time. The study enrolled 179 PAF patients (62 ± 10 years, 39% female) at 13 centres. At the index procedure, all PVs were successfully isolated with the pentaspline PFA catheter. Procedure and left atrial dwell times, with a 20-min waiting period, were 71.9 ± 17.6 and 41.0 ± 13.3 min, respectively. Fluoroscopy time was 11.5 ± 7.4 min. Notably, monitoring compliance was high, with 88.4 and 90.3% with weekly events and 72-h Holter monitors, respectively. Freedom from the composite primary effectiveness endpoint was 66.6%, and 41 patients had atrial tachyarrhythmia recurrence, mostly recurrent atrial fibrillation (31 patients). The composite safety endpoint occurred in two patients (1.1%), one tamponade and one transient ischaemic attack. There was no coronary spasm, PV stenosis, or AE fistula. There were four cases of transient phrenic nerve palsy, but all resolved during the index procedure. CONCLUSION: In this prospective, non-randomized, multicentre study, PVI using a pentaspline PFA catheter was effective in treating PAF patients despite rigourous endpoint definitions and high monitoring compliance and demonstrated favourable safety. REGISTRATION: Clinical Trials.gov Identifier: NCT05072964 (sponsor: Boston Scientific Corporation).

Patients on vitamin K treatment: is switching to direct-acting oral anticoagulation cost-effective? A target trial on a prospective cohort.

AIMS: Direct-acting oral anticoagulants (DOACs) have, to a substantial degree, replaced vitamin K antagonists (VKA) as treatments for stroke prevention in atrial fibrillation (AF) patients. However, evidence on the real-world causal effects of switching patients from VKA to DOAC is lacking. We aimed to assess the empirical incremental cost-effectiveness of switching patients to DOAC compared with maintaining VKA treatment. METHODS: The target trial approach was applied to the prospective observational Swiss-AF cohort, which enrolled 2415 AF patients from 2014 to 2017. Clinical data, healthcare resource utilisation and EQ-5D-based utilities representing quality of life were collected in yearly follow-ups. Health insurance claims were available for 1024 patients (42.4%). Overall survival, quality-of-life, costs from the Swiss statutory health insurance perspective and cost-effectiveness were estimated by emulating a target trial in which patients were randomly assigned to switch to DOAC or maintain VKA treatment. RESULTS: 228 patients switching from VKA to DOAC compared with 563 patients maintaining VKA treatment had no overall survival advantage over a 5-year observation period (HR 0.99, 95% CI 0.45, 1.55). The estimated gain in quality-adjusted life years (QALYs) was 0.003 over the 5-year period at an incremental costs of CHF 23 033 (€ 20 940). The estimated incremental cost-effectiveness ratio was CHF 425 852 (€ 387 138) per QALY gained. CONCLUSIONS: Applying a causal inference method to real-world data, we could not demonstrate switching to DOACs to be cost-effective for AF patients with at least 1 year of VKA treatment. Our estimates align with results from a previous randomised trial.

Impact of Comorbid Sleep-Disordered Breathing and Atrial Fibrillation on the Long-Term Outcome After Ischemic Stroke.

BACKGROUND: Sleep-disordered breathing (SDB) and atrial fibrillation (AF) are highly prevalent in patients with stroke and are recognized as independent risk factors for stroke. Little is known about the impact of comorbid SDB and AF on long-term outcomes after stroke. METHODS: In this prospective cohort study, 353 patients with acute ischemic stroke or transient ischemic attacks were analyzed. Patients were screened for SDB by respiratory polygraphy during acute hospitalization. Screening for AF was performed using a 7-day ECG up to 3× in the first 6 months. Follow-up visits were scheduled at 1, 3, 12, 24, and 36 months poststroke. Cox regression models adjusted for various factors (age, sex, body mass index, hypertension, diabetes, dyslipidemia, and heart failure) were used to assess the impact of comorbid SDB and AF on subsequent death or cerebro-cardiovascular events. RESULTS: Among 353 patients (299 ischemic stroke and 54 transient ischemic attacks), median age, 67 (interquartile range, 57-74) years with 63% males. Moderate-to-severe SDB (apnea-hypopnea index score, ≥15/h) was present in 118 (33.4%) patients. Among the 56 (15.9%) patients with AF, 28 had comorbid moderate-to-severe SDB and AF. Over 36 months, there were 12 deaths and 67 recurrent cerebro-cardiovascular events. Patients with comorbid moderate-to-severe SDB and AF had a higher risk of subsequent death or cerebro-cardiovascular events compared with those with only moderate-to-severe SDB without AF (hazard ratio, 2.49 [95% CI, 1.18-5.24]) and to those without moderate-to-severe SDB or AF (hazard ratio, 2.25 [95% CI, 1.12-4.50]). However, no significant difference was found between the comorbid moderate-to-severe SDB and AF group and the group with only AF without moderate-to-severe SDB (hazard ratio, 1.64 [95% CI, 0.62-4.36]). CONCLUSIONS: Comorbid moderate-to-severe SDB and AF significantly increase the risk of long-term mortality or recurrent cerebro-cardiovascular events after acute ischemic stroke. Considering both conditions as cumulative and modifiable cerebro-cardiovascular risk factors is of interest for the management of acute stroke. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02559739.

Epicardial adipose tissue dispersion at CT and recurrent atrial fibrillation after pulmonary vein isolation.

OBJECTIVES: Epicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF). Left atrial (LA) EAT dispersion on cardiac CT is a non-invasive imaging biomarker reflecting EAT heterogeneity. We aimed to investigate the association of LA EAT dispersion with AF recurrence after pulmonary vein isolation (PVI). METHODS: In a prospective registry of consecutive patients undergoing first PVI, mean EAT attenuation values were measured on contrast-enhanced cardiac CT scans in Hounsfield units (HU) within low (- 195 to - 45 HU) and high (- 44 to - 15 HU) threshold EAT compartments around the left atrium (LA). EAT dispersion was defined as the difference between the mean HU values within the two EAT compartments. Continuous variables were compared between groups using the Mann-Whitney U test and cox proportional hazard models were used to calculate hazard ratios of predictors of 1-year AF recurrence. RESULTS: A total of 208 patients were included, 135 with paroxysmal AF and 73 with persistent AF. LA EAT dispersion was significantly larger in patients with persistent compared to paroxysmal AF (52.6 HU vs. 49.9 HU; p = 0.001). After 1 year of follow-up, LA EAT dispersion above the mean (> 50.8 HU) was associated with a higher risk of AF recurrence (HR 2.3, 95% CI 1.5-3.6; p < 0.001). It retained its predictive value when corrected for age, sex, body mass index, LA volume, and AF type (HR 2.8, 95% CI 1.6-4.6; p < 0.001). CONCLUSION: A larger LA EAT dispersion on contrast-enhanced cardiac CT scans, reflecting EAT heterogeneity, is independently associated with AF recurrence after PVI. CLINICAL RELEVANCE STATEMENT: Based on LA EAT dispersion assessment, a more accurate risk stratification and patient selection may be possible based on a pre-procedural cardiac CT when planning PVI. KEY POINTS: • Epicardial adipose tissue (EAT) remodeling is associated with atrial fibrillation (AF). • A larger left atrial EAT dispersion in a pre-procedural cardiac CT was associated with a higher 1-year AF recurrence risk after pulmonary vein isolation. • A pre-procedural cardiac CT with left atrial EAT dispersion assessment may provide a more accurate risk stratification and patient selection for PVI.

Omega-3 Fatty Acids and Markers of Thrombosis in Patients with Atrial Fibrillation.

Omega-3 fatty acids (n-3 FAs) are associated with a lower risk of ischemic stroke in patients with atrial fibrillation (AF). Antithrombotic mechanisms may in part explain this observation. Therefore, we examined the association of n-3 FAs with D-dimer and beta-thromboglobulin (BTG), markers for activated coagulation and platelets, respectively. The n-3 FAs eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and alpha-linolenic acid (ALA) were determined via gas chromatography in the whole blood of 2373 patients with AF from the Swiss Atrial Fibrillation cohort study (ClinicalTrials.gov Identifier: NCT02105844). In a cross-sectional analysis, we examined the association of total n-3 FAs (EPA + DHA + DPA + ALA) and the association of individual fatty acids with D-dimer in patients with detectable D-dimer values (n = 1096) as well as with BTG (n = 2371) using multiple linear regression models adjusted for confounders. Median D-dimer and BTG levels were 0.340 ug/mL and 448 ng/mL, respectively. Higher total n-3 FAs correlated with lower D-dimer levels (coefficient 0.94, 95% confidence interval (Cl) 0.90-0.98, p = 0.004) and lower BTG levels (coefficient 0.97, Cl 0.95-0.99, p = 0.003). Likewise, the individual n-3 FAs EPA, DHA, DPA and ALA showed an inverse association with D-dimer. Higher levels of DHA, DPA and ALA correlated with lower BTG levels, whereas EPA showed a positive association with BTG. In patients with AF, higher levels of n-3 FAs were associated with lower levels of D-dimer and BTG, markers for activated coagulation and platelets, respectively. These findings suggest that n-3 FAs may exert antithrombotic properties in patients with AF.

Pulmonary vein isolation durability and lesion regression in patients with recurrent arrhythmia after pulsed-field ablation.

BACKGROUND: A novel multipolar pulsed-field ablation (PFA) catheter has recently been introduced for pulmonary vein isolation (PVI). Pre-market data showed high rates for PVI-durability during mandatory remapping studies. OBJECTIVE: To present post-market data in patients with recurrent arrhythmias. METHODS: Consecutive patients undergoing a redo procedure after an index PFA PVI using a bipolar-biphasic PFA system were included. 3-D electro-anatomical maps (3D-EAM) on redo procedure were compared to the 3D-EAM acquired after ablation during the index procedure. PVI durability was assessed on a per-vein and per-patient level and the sites of reconnections were identified. Furthermore, lesion extent around veins with durable isolation was compared to study lesion regression. RESULTS: Of 341 patients treated with a PFA PVI, 29 (8.5%) underwent a left atrial redo ablation due to arrhythmia recurrence. At the end of the index procedure, 110/112 veins (98%, four common ostia) were isolated. On redo procedures performed a median of 6 months after the first ablation, 3D-EAM identified 69/110 (63%) PVs with durable isolation. In 6 (21%) patients, all PVs were durably isolated. Reconnections were more often found on the right-sided veins and on the anterior aspects of the upper veins. Only minor lesion regression was observed between the index and redo procedure (a median of 3 mm (0 - 9.5) on the posterior wall). CONCLUSION: In patients with arrhythmia recurrence after PFA PVI using a first-generation PFA device, durable isolation was observed in 63% of the veins and 21% of the patients showed durable isolation of all previously isolated veins.