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.

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.

Concomitant atrial fibrillation ablation in minimally invasive cardiac surgery

Concomitant atrial fibrillation (AF) ablation in cardiac surgery effectively restores sinus rhythm and may reduce morbidity and mortality. Cardiac surgery has witnessed the transition from the historical Cox Maze procedure to more modern and less invasive approaches for concomitant AF treatment. As minimally invasive cardiac surgery gains traction, ablation methods and careful patient selection become crucial to optimize results. Emerging techniques, including bipolar epicardial radiofrequency and endo/epicardial cryoablation, are central to these advances, targeting specific arrhythmogenic areas within the atria. While pulmonary vein isolation (PVI) is essential, it may be insufficient for patients with persistent or longstanding persistent AF. In such cases, left atrial posterior wall isolation has proven beneficial. Furthermore, recent studies emphasize the significance of left atrial appendage occlusion in concurrent AF treatments, highlighting its role in stroke risk reduction. Notably, the left atrium remains the focal point for concomitant AF surgery over the right, primarily due to concerns like high pacemaker implantation rates and complexities of right atrial ablation sets. Although guidelines support its widespread use, concomitant AF ablation outcomes vary based on patient selection, surgeon's expertise, and clinical context and thus the Heart Team's input is crucial for individualized decisions. In the upcoming sections, we present our patient selection and a visual guide to our techniques for concomitant AF surgery in minimally invasive mitral valve, coronary artery bypass and aortic valve surgery.

Clinical Outcomes by Sex After Pulsed Field Ablation of Atrial Fibrillation

Importance

Previous studies evaluating the association of patient sex with clinical outcomes using conventional thermal ablative modalities for atrial fibrillation (AF) such as radiofrequency or cryoablation are controversial due to mixed results. Pulsed field ablation (PFA) is a novel AF ablation energy modality that has demonstrated preferential myocardial tissue ablation with a unique safety profile.

Objective

To compare sex differences in patients undergoing PFA for AF in the Multinational Survey on the Methods, Efficacy, and Safety on the Postapproval Clinical Use of Pulsed Field Ablation (MANIFEST-PF) registry.

Design, Setting, and Participants

This was a retrospective cohort study of MANIFEST-PF registry data, which included consecutive patients undergoing postregulatory approval treatment with PFA to treat AF between March 2021 and May 2022 with a median follow-up of 1 year. MANIFEST-PF is a multinational, retrospectively analyzed, prospectively enrolled patient-level registry including 24 European centers. The study included all consecutive registry patients (age ≥18 years) who underwent first-ever PFA for paroxysmal or persistent AF.

Exposure

PFA was performed on patients with AF. All patients underwent pulmonary vein isolation and additional ablation, which was performed at the discretion of the operator.

Main Outcomes and Measures

The primary effectiveness outcome was freedom from clinically documented atrial arrhythmia for 30 seconds or longer after a 3-month blanking period. The primary safety outcome was the composite of acute (<7 days postprocedure) and chronic (>7 days) major adverse events (MAEs).

Results

Of 1568 patients (mean [SD] age, 64.5 [11.5] years; 1015 male [64.7%]) with AF who underwent PFA, female patients, as compared with male patients, were older (mean [SD] age, 68 [10] years vs 62 [12] years; P < .001), had more paroxysmal AF (70.2% [388 of 553] vs 62.4% [633 of 1015]; P = .002) but had fewer comorbidities such as coronary disease (9% [38 of 553] vs 15.9% [129 of 1015]; P < .001), heart failure (10.5% [58 of 553] vs 16.6% [168 of 1015]; P = .001), and sleep apnea (4.7% [18 of 553] vs 11.7% [84 of 1015]; P < .001). Pulmonary vein isolation was performed in 99.8% of female (552 of 553) and 98.9% of male (1004 of 1015; P = .90) patients. Additional ablation was performed in 22.4% of female (124 of 553) and 23.1% of male (235 of 1015; P = .79) patients. The 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was similar in male and female patients (79.0%; 95% CI, 76.3%-81.5% vs 76.3%; 95% CI, 72.5%-79.8%; P = .28). There was also no significant difference in acute major AEs between groups (male, 1.5% [16 of 1015] vs female, 2.5% [14 of 553]; P = .19).

Conclusion and Relevance

Results of this cohort study suggest that after PFA for AF, there were no significant sex differences in clinical effectiveness or safety events.

EUropean real-world outcomes with Pulsed field ablatiOn in patients with symptomatic atRIAl fibrillation: lessons from the multi-centre EU-PORIA registry

AIMS

Pulsed field ablation (PFA) is a new, non-thermal ablation modality for pulmonary vein (PV) isolation in patients with atrial fibrillation (AF). The multi-centre EUropean Real World Outcomes with Pulsed Field AblatiOn in Patients with Symptomatic AtRIAl Fibrillation (EU-PORIA) registry sought to determine the safety, efficacy, and learning curve characteristics for the pentaspline, multi-electrode PFA catheter.

METHODS AND RESULTS

All-comer AF patients from seven high-volume centres were consecutively enrolled. Procedural and follow-up data were collected. Learning curve effects were analysed by operator ablation experience and primary ablation modality. In total, 1233 patients (61% male, mean age 66 ± 11years, 60% paroxysmal AF) were treated by 42 operators. In 169 patients (14%), additional lesions outside the PVs were performed, most commonly at the posterior wall (n = 127). Median procedure and fluoroscopy times were 58 (interquartile range: 40-87) and 14 (9-21) min, respectively, with no differences due to operator experience. Major complications occurred in 21/1233 procedures (1.7%) including pericardial tamponade (14; 1.1%) and transient ischaemic attack or stroke (n = 7; 0.6%), of which one was fatal. Prior cryoballoon users had less complication. At a median follow-up of 365 (323-386) days, the Kaplan-Meier estimate of arrhythmia-free survival was 74% (80% for paroxysmal and 66% for persistent AF). Freedom from arrhythmia was not influenced by operator experience. In 149 (12%) patients, a repeat procedure was performed due to AF recurrence and 418/584 (72%) PVs were durably isolated.

CONCLUSION

The EU-PORIA registry demonstrates a high single-procedure success rate with an excellent safety profile and short procedure times in a real-world, all-comer AF patient population.

Safety and Effectiveness of Pulsed Field Ablation to Treat Atrial Fibrillation: One-Year Outcomes From the MANIFEST-PF Registry

BACKGROUND

Pulsed field ablation is a novel nonthermal cardiac ablation modality using ultra-rapid electrical pulses to cause cell death by a mechanism of irreversible electroporation. Unlike the traditional ablation energy sources, pulsed field ablation has demonstrated significant preferentiality to myocardial tissue ablation, and thus avoids certain thermally mediated complications. However, its safety and effectiveness remain unknown in usual clinical care.

METHODS

MANIFEST-PF (Multi-National Survey on the Methods, Efficacy, and Safety on the Post-Approval Clinical Use of Pulsed Field Ablation) is a retrospective, multinational, patient-level registry wherein patients at each center were prospectively included in their respective center registries. The registry included all patients undergoing postapproval treatment with a multielectrode 5-spline pulsed field ablation catheter to treat atrial fibrillation (AF) between March 1, 2021, and May 30, 2022. The primary effectiveness outcome was freedom from clinical documented atrial arrhythmia (AF/atrial flutter/atrial tachycardia) of ≥30 seconds on the basis of electrocardiographic data after a 3-month blanking period (on or off antiarrhythmic drugs). Safety outcomes included the composite of acute (<7 days postprocedure) and latent (>7 days) major adverse events.

RESULTS

At 24 European centers (77 operators) pulsed field ablation was performed in 1568 patients with AF: age 64.5±11.5 years, female 35%, paroxysmal/persistent AF 65%/32%, CHA₂DS₂-VASc 2.2±1.6, median left ventricular ejection fraction 60%, and left atrial diameter 42 mm. Pulmonary vein isolation was achieved in 99.2% of patients. After a median (interquartile range) follow-up of 367 (289-421) days, the 1-year Kaplan-Meier estimate for freedom from atrial arrhythmia was 78.1% (95% CI, 76.0%-80.0%); clinical effectiveness was more common in patients with paroxysmal AF versus persistent AF (81.6% versus 71.5%; P=0.001). Acute major adverse events occurred in 1.9% of patients.

CONCLUSIONS

In this large observational registry of the postapproval clinical use of pulsed field technology to treat AF, catheter ablation using pulsed field energy was clinically effective in 78% of patients with AF.

A worldwide survey on incidence, management and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: The POTTER-AF study

AIMS

Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management and outcome are sparse.

METHODS AND RESULTS

This international multicenter registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553,729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed at 214 centers in 35 countries. In 78 centers 138 patients (0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (p<0.0001)) were diagnosed with an oesophageal fistula. Periprocedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8%, and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) (odds ratio 7.463 (2.414, 23.072) p<0.001).

CONCLUSIONS

Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high.

COMPARE LAAO: Rationale and design of the randomized controlled trial "COMPARing Effectiveness and safety of Left Atrial Appendage Occlusion to standard of care for atrial fibrillation patients at high stroke risk and ineligible to use oral anticoagulation therapy"

BACKGROUND

Left atrial appendage occlusion (LAAO) provides an alternative to oral anticoagulation (OAC) for stroke prevention in patients with atrial fibrillation (AF). In patients with a long-term or permanent contraindication for OAC randomized controlled trial (RCT) data is lacking.

STUDY OBJECTIVES

To assess the efficacy and safety of LAAO in AF patients who are ineligible to use OAC. The co-primary efficacy endpoint is (1) time to first occurrence of stroke (ischemic, hemorrhagic, or undetermined) and (2) time to first occurrence of the composite of stroke, transient ischemic attack (TIA), and systemic embolism (SE). The primary safety endpoint is the 30-day rate of peri-procedural complications.

STUDY DESIGN

This is a multicenter, investigator-initiated, open-label, blinded endpoint (PROBE), superiority-driven RCT. Patients with AF, a CHA₂DS₂-VASc score ≥2 for men and ≥3 for women and a long-term or permanent contraindication for OAC will be randomized in a 2:1 fashion to the device- or control arm. Patients in the device arm will undergo percutaneous LAAO and will receive post-procedural dual antiplatelet therapy (DAPT) per protocol, while those in the control arm will continue their current treatment consisting of no antithrombotic therapy or (D)APT as deemed appropriate by the primary responsible physician. In this endpoint-driven trial design, assuming a 50% lower stroke risk of LAAO compared to conservative treatment, 609 patients will be followed for a minimum of 1 and a maximum of 5 years. Cost-effectiveness and budget impact analyses will be performed to allow decision-making on reimbursement of LAAO for the target population in the Netherlands.

SUMMARY

The COMPARE LAAO trial will investigate the clinical superiority in preventing thromboembolic events and cost-effectiveness of LAAO in AF patients with a high thromboembolic risk and a contraindication for OAC use.

NCT TRIAL NUMBER

NCT04676880.

Multi-national survey on the methods, efficacy, and safety on the post-approval clinical use of pulsed field ablation (MANIFEST-PF)

AIMS

Pulsed field ablation (PFA) is a novel atrial fibrillation (AF) ablation modality that has demonstrated preferential tissue ablation, including no oesophageal damage, in first-in-human clinical trials. In the MANIFEST-PF survey, we investigated the 'real world' performance of the only approved PFA catheter, including acute effectiveness and safety-in particular, rare oesophageal effects and other unforeseen PFA-related complications.

METHODS AND RESULTS

This retrospective survey included all 24 clinical centres using the pentaspline PFA catheter after regulatory approval. Institution-level data were obtained on patient characteristics, procedure parameters, acute efficacy, and adverse events. With an average of 73 patients treated per centre (range 7-291), full cohort included 1758 patients: mean age 61.6 years (range 19-92), female 34%, first-time ablation 94%, paroxysmal/persistent AF 58/35%. Most procedures employed deep sedation without intubation (82.1%), and 15.1% were discharged same day. Pulmonary vein isolation (PVI) was successful in 99.9% (range 98.9-100%). Procedure time was 65 min (38-215). There were no oesophageal complications or phrenic nerve injuries persisting past hospital discharge. Major complications (1.6%) were pericardial tamponade (0.97%) and stroke (0.4%); one stroke resulted in death (0.06%). Minor complications (3.9%) were primarily vascular (3.3%), but also included transient phrenic nerve paresis (0.46%), and TIA (0.11%). Rare complications included coronary artery spasm, haemoptysis, and dry cough persistent for 6 weeks (0.06% each).

CONCLUSION

In a large cohort of unselected patients, PFA was efficacious for PVI, and expressed a safety profile consistent with preferential tissue ablation. However, the frequency of 'generic' catheter complications (tamponade, stroke) underscores the need for improvement.

Design and rationale of DUTCH-AF: a prospective nationwide registry programme and observational study on long-term oral antithrombotic treatment in patients with atrial fibrillation

INTRODUCTION

Anticoagulation therapy is pivotal in the management of stroke prevention in atrial fibrillation (AF). Prospective registries, containing longitudinal data are lacking with detailed information on anticoagulant therapy, treatment adherence and AF-related adverse events in practice-based patient cohorts, in particular for non-vitamin K oral anticoagulants (NOAC). With the creation of DUTCH-AF, a nationwide longitudinal AF registry, we aim to provide clinical data and answer questions on the (anticoagulant) management over time and of the clinical course of patients with newly diagnosed AF in routine clinical care. Within DUTCH-AF, our current aim is to assess the effect of non-adherence and non-persistence of anticoagulation therapy on clinical adverse events (eg, bleeding and stroke), to determine predictors for such inadequate anticoagulant treatment, and to validate and refine bleeding prediction models. With DUTCH-AF, we provide the basis for a continuing nationwide AF registry, which will facilitate subsequent research, including future registry-based clinical trials.

METHODS AND ANALYSIS

The DUTCH-AF registry is a nationwide, prospective registry of patients with newly diagnosed 'non-valvular' AF. Patients will be enrolled from primary, secondary and tertiary care practices across the Netherlands. A target of 6000 patients for this initial cohort will be followed for at least 2 years. Data on thromboembolic and bleeding events, changes in antithrombotic therapy and hospital admissions will be registered. Pharmacy-dispensing data will be obtained to calculate parameters of adherence and persistence to anticoagulant treatment, which will be linked to AF-related outcomes such as ischaemic stroke and major bleeding. In a subset of patients, anticoagulation adherence and beliefs about drugs will be assessed by questionnaire.

ETHICS AND DISSEMINATION

This study protocol was approved as exempt for formal review according to Dutch law by the Medical Ethics Committee of the Leiden University Medical Centre, Leiden, the Netherlands. Results will be disseminated by publications in peer-reviewed journals and presentations at scientific congresses.

TRIAL REGISTRATION NUMBER

Trial NL7467, NTR7706 (https://www.trialregister.nl/trial/7464).

Regional collaboration to improve atrial fibrillation care: Preliminary data from the Netherlands heart network

BACKGROUND

Guideline non-adherence and variations in therapeutic and diagnostic trajectories result in suboptimal atrial fibrillation (AF) treatments. Large academic and referral hospitals demonstrated positive effects of dedicated outpatient AF clinics. Although similar results have not been indicated in (small) non-academic hospitals yet, ample opportunities are present when collaboration is initiated on a regional level. Therefore, this study assesses the effectiveness of outpatient AF clinics in a collaborative region in the Netherlands.

METHODS

For this study baseline and 6 months follow-up data of a prospective cohort including newly or recently diagnosed AF-patients of 4 hospitals involved in the Netherlands Heart Network are used. From January'15 to March'16 patient relevant outcome measures (ie EHRA score, stroke, major bleedings, hospitalizations, serious adverse effects of medication, and mortality) are gathered. Descriptive and regression analyses are performed to assess the effectiveness of outpatient AF clinics.

RESULTS

In the analyses 448 AF-patients were included. After 6 months, significant improvements regarding EHRA score (P < 0.01), hypertension (P < 0.01), and type of AF (P < 0.01) were indicated. Results of the patient relevant outcomes showed that AF-patients were hospitalized 23 times, no major bleedings and 2 strokes occurred. Furthermore, 0 AF-patients reported serious adverse effects of medication and no AF-patients deceased.

CONCLUSIONS

Collaboration between cardiologists in a regional setting permits further improvement of AF care. Therefore, such quality targets are not exclusively reserved to large academic or referral hospitals. Although promising, future research should put effort in measuring the effectiveness of the outpatient AF clinics also on the long run.

Type D personality affects health-related quality of life in patients with lone atrial fibrillation by increasing symptoms related to sympathetic activation

BACKGROUND

Health-related quality of life (HRQoL) is impaired in patients with atrial fibrillation (AF), and even more so in patients with a Distressed personality type (Type D). It is unknown whether this extends to patients with 'lone AF'. Since chronic stress is associated with increased arousal, it might affect recurrences and thus HRQoL. The current study examined the influence of Type D on the trajectory of disease-specific and generic HRQoL, compared it with HRQoL in the general population, and assessed the mediating role of arousal symptoms (e.g., tachycardia, sweating).

METHODS

159 patients with 'lone AF' (age: 61.6±0.8, 63% men, 3.3±5.0 years since diagnosis) filled out a survey on personality (Type D: DS14), quality of life (SF-36, AFQoL) and symptoms (ATSSS) of AF at inclusion, and 6, 12, and 18 months later. Linear mixed modeling was used.

RESULTS

Generic HRQoL was reduced as compared to the general population, and all HRQoL scales remained stable across time. Type D personality was a significant predictor of worse disease-specific (estimate= -17.1 ; 95%CI:-23.9 - -10.2; p<.001), and generic HRQoL (estimate_PCS=-5.5; 95%CI:-9.3 - -1.8; p=.004; estimate_MCS=-14.8; 95%CI:-18.9- -10.6; p<.001), with arousal symptoms accounting for substantial change in the Type D estimate, suggesting partially shared variance between Type D and arousal symptoms in predicting HRQoL.

CONCLUSION

HRQoL was stable across time, and systematically poorer in distressed 'lone AF' patients. Arousal symptoms partly explained the relation between Type D and HRQoL. Chronic distress may affect AF patients' HRQoL through sympathetic activation and accompanying complaints.

Real life dabigatran and metabolite concentrations, focused on inter-patient variability and assay differences in patients with atrial fibrillation

Background:

Dabigatran is prescribed to increasing numbers of patients with atrial fibrillation (AF). Although routine monitoring is not considered to be useful, measuring drug concentrations can be clinically relevant in specific situations. The aim of this study was the comparison of different functional and non-functional assays for determination of dabigatran concentrations at different timepoints in a real-life patient population with AF. We focused on the differences between assays in identifying patients with low drug concentrations. Furthermore, we studied the effect of glucuronidation on the established concentration as determined with different assays.

Methods:

This study established dabigatran concentration ranges in 40 real-life AF patients by an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) reference method and compared these with results from coagulation assays (Hemoclot dTT, LD-dTT and ECA). Samples were taken just before and 2 and 4 h after taking the drug.

Results:

A wide range of concentrations at different time points was found in this patient group. Coagulation assays correlate best with UPLC-MS/MS results that include the glucuronidated metabolites, showing that the pharmacologically active glucuronides are also measured in coagulation testing. The LD-dTT has the best agreement with UPLC-MS/MS and combines good sensitivity with high specificity. Several patients show consistently low or high drug concentrations, implying that drug exposure differs between patients.

Conclusions:

Based on the association of dabigatran concentrations with bleeding and thromboembolic risk, we believe that dabigatran monitoring could be beneficial for further optimizing anticoagulation therapy in AF.

Multielectrode Pulmonary Vein Isolation Versus Single Tip Wide Area Catheter Ablation for Paroxysmal Atrial Fibrillation

Background—

Single-shot ablation techniques may facilitate safe and simple pulmonary vein isolation to treat paroxysmal atrial fibrillation. Multielectrode pulmonary vein isolation versus single tip wide area catheter ablation-paroxysmal atrial fibrillation is the first multinational, multicenter, prospective, noninferiority randomized clinical trial comparing multielectrode-phased radiofrequency ablation (MEA) to standard focal irrigated radiofrequency ablation (STA) using 3-dimensional navigation.

Methods and Results—

Patients with paroxysmal atrial fibrillation were randomized to MEA (61 patients) or STA (59 patients). Preprocedure transesophageal echocardiogram and computed tomography/magnetic resonance imaging (also 6-month postprocedure) were performed. Mean age was 57 years, 25% female sex, BMI was 28, CHA 2 DS 2 –VASc score was 0 to 1 in 82%, 8% had previous right atrial ablation, whereas all had at least 1 antiarrhythmic drug failure. The MEA group had significantly shorter mean procedure time (96±36 versus 166±46 minutes, P <0.001) and fluoroscopy time (23±9 versus 27±9 minutes, P =0.023). The total radiofrequency energy duration was 22±8 minutes for MEA versus 36±13 minutes for STA ( P <0.001) with confirmed pulmonary vein isolation in all patients. Hospital admission was 1 day in both groups, without major adverse events either during the procedure or during 30-day follow-up. Two patients in the STA group had 1 PV with asymptomatic narrowing >50%. Freedom of atrial fibrillation for MEA and STA was 86.4% and 89.7% at 6 months, dropping to 76.3% and 81.0% at 12 months.

Conclusions—

In this multicenter, randomized clinical trial, MEA and STA had similar rates of single-procedure acute pulmonary vein isolation without serious adverse events in the first 30 days. MEA had slightly lower long-term arrhythmia freedom, but showed marked and significantly shorter procedure, fluoroscopy, and radiofrequency energy times.

Clinical Trial Registration—

URL: www.clinicaltrials.gov ; Unique identifier: NCT01696136.

Attrition and adherence in a WEB-Based Distress Management Program for Implantable Cardioverter defibrillator Patients (WEBCARE): randomized controlled trial

Background

WEB-Based Distress Management Program for Implantable CARdioverter defibrillator Patients (WEBCARE) is a Web-based randomized controlled trial, designed to improve psychological well-being in patients with an implantable cardioverter defibrillator (ICD). As in other Web-based trials, we encountered problems with attrition and adherence.

Objective

In the current study, we focus on the patient characteristics, reasons, and motivation of (1) completers, (2) those who quit the intervention, and (3) those who quit the intervention and the study in the treatment arm of WEBCARE.

Methods

Consecutive first-time ICD patients from six Dutch referral hospitals were approached for participation. After signing consent and filling in baseline measures, patients were randomized to either the WEBCARE group or the Usual Care group.

Results

The treatment arm of WEBCARE contained 146 patients. Of these 146, 34 (23.3%) completed the treatment, 88 (60.3%) dropped out of treatment but completed follow-up, and 24 (16.4%) dropped out of treatment and study. Results show no systematic differences in baseline demographic, clinical, or psychological characteristics between groups. A gradual increase in dropout was observed with 83.5% (122/146) completing the first lesson, while only 23.3% (34/146) eventually completed the whole treatment. Reasons most often given by patients for dropout were technical problems with the computer, time constraints, feeling fine, and not needing additional support.

Conclusions

Current findings underline the importance of focusing on adherence and dropout, as this remains a significant problem in behavioral Web-based trials. Examining possibilities to address barriers indicated by patients might enhance treatment engagement and improve patient outcomes.

Trial Registration

Clinicaltrials.gov: NCT00895700; http://www.clinicaltrials.gov/ct2/show/NCT00895700 (Archived by WebCite at http://www.webcitation.org/6NCop6Htz).

Rationale and design of WEBCARE: a randomized, controlled, web-based behavioral intervention trial in cardioverter-defibrillator patients to reduce anxiety and device concerns and enhance quality of life

Background

The implantable cardioverter defibrillator (ICD) is generally well accepted, but 25-33% of patients experience clinical levels of anxiety, depression, and impaired quality of life (QoL) following implantation. Few trials in ICD patients have investigated whether behavioral intervention may mitigate the development of these adjustment problems. We present the rationale and study design of the WEB-based distress management program for implantable CARdioverter dEfibrillator patients (WEBCARE) trial.

Methods

WEBCARE is a multi-center, multi-disciplinary, randomized, controlled behavioral intervention trial designed to examine the effectiveness of a web-based approach in terms of reducing levels of anxiety and device concerns and enhancing QoL. Consecutive patients hospitalized for the implantation of an ICD will be approached for study participation while in hospital and randomized to the intervention arm (n = 175) versus usual care (n = 175) at baseline (5-10 days post implantation). Patients will complete assessments of patient-centered outcomes at baseline, 14, 26, and 52 weeks after implantation. Patients randomized to the intervention arm will receive a 12-week web-based behavioral intervention starting 2 weeks after implantation. Primary endpoints include (i_i) patient-centered outcomes (i.e., anxiety, depression, ICD acceptance, QoL); (i_ii) health care utilization; and (i_iii) cost-effectiveness. All primary endpoints will be assessed with standardized and validated disease-specific or generic questionnaires. Secondary endpoints include (ii_i) cortisol awakening response; and (ii_ii) ventricular arrhythmias.

Discussion

WEBCARE will show whether a behavioral intervention using a web-based approach is feasible and effective in reducing anxiety and ICD concerns and improving QoL in ICD patients.

Trial Registration

http://www.ClinicalTrials.gov. Identifier: NCT00895700.

Inhibitors of the Na+/H+ Exchanger Cannot Prevent Atrial Electrical Remodeling in the Goat

INTRODUCTION

It has been suggested that blockade of the Na+/H+ exchanger (NHE1) can prevent atrial fibrillation (AF)-induced electrical remodeling and the development of AF.

METHODS AND RESULTS

AF was maintained by burst pacing in 10 chronically instrumented conscious goats. Intravenous and oral dosages of two NHE1 blockers (EMD87580 and EMD125021) resulted in plasma levels several magnitudes higher than required for effective NHE1 blockade. Shortening of atrial refractoriness immediately after 5 minutes of AF was not prevented by NHE1 blockade. In remodeled atria, increasing dosages of EMD87580 and EMD125021 did not reverse shortening of the atrial refractory period or reduce the duration of AF episodes. The cycle length during persistent AF also was not affected. Oral pretreatment with EMD87580 (8 mg/kg bid) starting 3 days before AF could not prevent electrical remodeling. After 24 and 48 hours of remodeling, the duration of AF paroxysms was 47 +/- 32 seconds and 135 +/- 63 seconds compared to 56 +/- 17 seconds and 136 +/- 52 seconds in placebo-treated animals (P > 0.8), respectively.

CONCLUSION

In the goat model of AF, the Na+/H+ exchanger inhibitors EMD87580 and EMD125021 did not prevent or revert AF-induced electrical remodeling. This indicates that activation of the Na+/H+ exchanger is not involved in the intracellular pathways of electrical remodeling. This does not support the suggestion that blockers of the Na+/H+ exchanger may be beneficial for prevention and treatment of AF.