Prevalence, Timing, and Impact of Early Recurrence of Atrial Tachyarrhythmias after Pulsed Field Ablation: A Secondary Analysis of the PULSED AF Trial.

BACKGROUND: Early recurrence of atrial tachyarrhythmias (ERATs) within three months following thermal ablation for atrial fibrillation (AF) is common and often considered transient. Pulsed field ablation (PFA) is a non-thermal energy source in which ERAT is not well described. OBJECTIVE: To analyze ERAT in AF patients undergoing PFA in the PULSED AF trial. METHODS: This analysis included 294 patients (154 paroxysmal, 140 persistent AF) that had ≥10 rhythm assessments during the 90-day blanking period. ERAT was defined as any instance of ≥30s of AF, atrial flutter, or atrial tachycardia on trans-telephonic monitoring (weekly and symptomatic) or ≥10s on ECG (at 3 months), both within 90 days. Late recurrence of atrial tachyarrhythmias (LRATs) was defined as observed atrial tachyarrhythmias between 90 days and 12 months. RESULTS: The overall prevalence of ERAT was 27.1% in paroxysmal and 31.6% in persistent AF patients. In patients with ERAT, 73% had ERAT onset within the first month post-procedure. Presence of ERAT was associated with LRAT in paroxysmal (HR 6.4 (95% c.i. 3.6-11.3)) and persistent (HR 3.8 (95% c.i. 2.2-6.6)) AF patients. Yet, in 29.4% of paroxysmal and 34.3% of persistent AF patients with ERAT, LRAT was not observed. LRAT was positively correlated with the number of ERAT observations. CONCLUSION: ERAT post PFA predicted LRAT in paroxysmal and persistent AF patients. However, the concept of a blanking period post PFA is still valid as approximately 1/3 of patients with ERAT did not continue on to LRAT during follow-up and may not need re-ablation.

Randomized prospective evaluation of same-day discharge after cryoballoon ablation of atrial fibrillation: results of the EASY PVI study.

BACKGROUND: With advancements in technology and ablation techniques, catheter ablation for the treatment of atrial fibrillation (AF) has become safer with time. In the past, standard-of-care recommended overnight stay for outpatient procedures. As safety has improved and procedure times have shortened, some centers have allowed for same-day discharge. We report the results of a multi-center, randomized clinical trial investigating the safety of same-day discharge post-cryoballoon ablation. METHODS: Patients with paroxysmal atrial fibrillation underwent pulmonary vein isolation (PVI) with the Medtronic Arctic Advance cryoballoon at 3 US centers. Six hours after the procedure, patients were randomized to either stay overnight or be discharged same day. RESULTS: A total of 49 patients were enrolled. Two patients were withdrawn prior to randomization. One patient chose to withdraw after randomization. Of the 22 patients randomized to same-day discharge and the 23 patients randomized the overnight stay, no significant adverse outcomes were reported in either group. Occurrence of adverse events did not differ significantly between the two groups. Procedure time and fluoroscopy time did not significantly differ between groups. CONCLUSIONS: This is the first randomized trial examining the safety of same-day discharge post-cryoballoon ablation. Based on our results, same-day discharge following cryoballoon ablation for paroxysmal AF is a safe option following uncomplicated ablation for PVI. Operators should use their discretion in selecting patients for same-day discharge.

Achieving regioselective materials binding using multidomain peptides.

The ability to integrate two disparate materials-binding domains into a single ligand to achieve regiospecific binding would be powerful to direct material assembly; however, this has proven challenging to achieve due to cross-materials binding. Accomplishing this goal might be achieved by harnessing the precision of biology to exploit the recognition between peptides and specific nanomaterials. Here, a designed bifunctional molecule termed Biomolecular Exfoliant and Assembly Motifs (BEAM) is introduced, featuring two different materials-binding peptide domains, one for graphene and one for hexagonal boron nitride (h-BN), at each end of the molecule, separated by a fatty acid spacer. The BEAM is demonstrated to bind strongly to both graphene and h-BN surfaces, and in each case the materials-binding peptide domain is shown to preferentially bind its target material. Critically, the two materials-binding domains exhibited limited cross-domain interaction. The BEAM design concept shows substantial potential to eventually guide self-organization of a range of materials in aqueous media.

Cryoballoon ablation of pulmonary veins for persistent atrial fibrillation: Results from the multicenter STOP Persistent AF trial.

BACKGROUND: Pulmonary vein isolation (PVI) is the cornerstone of catheter ablation to treat patients with symptomatic drug-refractory atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to assess the safety and efficacy of PVI using the cryoballoon catheter to treat patients with persistent AF. METHODS: STOP Persistent AF (ClinicalTrials.gov Identifier: NCT03012841) was a prospective, multicenter, single-arm, Food and Drug Administration-regulated trial designed to evaluate the safety and efficacy of PVI-only cryoballoon ablation for drug-refractory persistent AF (continuous episodes <6 months). The primary efficacy endpoint was 12-month freedom from ≥30 seconds of AF, atrial flutter (AFL), or atrial tachycardia (AT) after a 90-day blanking period. The prespecified performance goals were set at >40% and <13% for the primary efficacy and safety endpoints, respectively. Secondary endpoints assessed quality of life using the AFEQT (Atrial Fibrillation Effect on Quality of Life) and SF (Short Form)-12 questionnaires. RESULTS: Of 186 total enrollments, 165 subjects (70% male; age 65 ± 9 years; left atrial diameter 4.2 ± 0.6 cm; body mass index 31 ± 6) were treated at 25 sites in the United States, Canada, and Japan. Total procedural, left atrial dwell, and fluoroscopy times were 121 ± 46 minutes, 102 ± 41 minutes, and 19 ± 16 minutes, respectively. At 12 months, the primary efficacy endpoint was 54.8% (95% confidence [CI] 46.7%-62.1%) freedom from AF, AFL, or AT. There was 1 primary safety event, translating to a rate of 0.6% (95% CI 0.1%-4.4%). AFEQT and SF-12 assessments demonstrated significant improvements from baseline to 12 months postablation (P <.001). CONCLUSION: The STOP Persistent AF trial demonstrated cryoballoon ablation to be safe and effective in treating patients with drug-refractory persistent AF characterized by continuous AF episodes <6 months.

Sustained quality-of-life improvement post-cryoballoon ablation in patients with paroxysmal atrial fibrillation: Results from the STOP-AF Post-Approval Study.

BACKGROUND: Pulmonary vein isolation by catheter ablation is a class IA indication for the treatment of symptomatic, drug-refractory, paroxysmal atrial fibrillation (PAF). Quality of life (QoL) has been identified as a clinically meaningful endpoint but has not been comprehensively evaluated to date. OBJECTIVE: The purpose of this study was to evaluate the effects of cryoballoon ablation on long-term QoL. METHODS: As part of the STOP-AF Post-Approval Study, QoL was assessed using the Short Form-12 Health Survey (SF-12) along with evaluation of arrhythmia-related symptoms through 36 months. A multivariate linear mixed effects regression was used to determine the association between atrial fibrillation symptoms and QoL scores, and univariate linear regressions were used to assess predictors of 36-month change in QoL scores. RESULTS: Three hundred thirty-five subjects fully completed SF-12 forms at baseline, with 319, 308, 291, and 278 subjects completing surveys at the subsequent follow-up visits. Both physical and mental composite scores increased significantly from baseline (P <.001), and all arrhythmia symptoms significantly decreased from baseline (P <.001), with 62.0% of subjects reporting no symptoms at 6 months compared to 5.7% at baseline (P <.001). Presence of dyspnea and fatigue at baseline were univariate predictors of physical QoL improvement (P = .045 and 0.0497, respectively), whereas each year of age and each year of PAF duration were predictors of a decrease in mental QoL (P = .014 and .04, respectively). CONCLUSION: Cryoballoon ablation for treatment of PAF results in a significant, and sustained, QoL improvement. The observed improvement in physical and mental health likely may be mediated by a reduction in symptom and arrhythmia burden.

Long-Term Outcomes After Ablation for Paroxysmal Atrial Fibrillation Using the Second-Generation Cryoballoon: Final Results From STOP AF Post-Approval Study.

OBJECTIVES: STOP AF PAS (Sustained Treatment of Paroxysmal Atrial Fibrillation Post-Approval Study) is the first prospective, multicenter, 3-year study in North America to assess long-term safety and effectiveness of the cryoballoon for treatment of patients with drug-refractory symptomatic pAF. BACKGROUND: The STOP AF PAS was required by the U.S. Food and Drug Administration at the time of approval of the first-generation cryoballoon for the treatment of paroxysmal atrial fibrillation (pAF). The second-generation cryoballoon (CB2) was commercially released shortly after this trial was initiated. METHODS: The study was nonrandomized. Enrollment was completed with 344 eligible patients undergoing pulmonary vein isolation (PVI) using the CB2. Procedure-related safety and freedom from AF and symptomatic atrial flutter/atrial tachycardia through 3 years were determined. Documented atrial arrhythmias ≥30 s were considered treatment failures. RESULTS: Acute PVI was achieved in 99.3% (1,341 of 1,350) of veins. Mean follow-up was 34 ± 7 months. The rate of major complications was 5.8%, including a 3.2% rate of phrenic nerve injury, which resolved in all but 1 patient by 36 months. At 36 months, 11.7% of patients were prescribed antiarrhythmic agents, inclusive of "pill-in-the-pocket" administration. Freedom from AF was 81.6% at 12 months, 73.8% at 24 months, and 68.1% at 36 months. Freedom from AF and symptomatic atrial flutter/atrial tachycardia was 79.0% at 12 months, 70.8% at 24 months, and 64.1% at 36 months. Freedom from a repeat ablation procedure was 80.9% at 36 months. CONCLUSIONS: PVI using the CB2 was an effective treatment for patients with pAF, with freedom from all atrial arrhythmias of 64% at 36 months. (Sustained Treatment of Paroxysmal Atrial Fibrillation Post-Approval Study [STOP AF PAS]; NCT01456949).

Clinical evaluation of a novel 12-hole irrigated tip catheter ablation system for the treatment of typical atrial flutter-results from the Duo FLAIR clinical study.

INTRODUCTION: Higher current density at the proximal end of a six-hole catheter is not irrigated and thus could lead to uneven heating and possibly coagulum and charring. This study tested a novel 12-hole irrigated catheter with six additional holes at the proximal end that provides more uniform cooling during atrial flutter (AFL) ablation. METHODS: A total of 188 patients (28 females, 66 ± 11 years) were treated for typical AFL at 22 sites in the USA and Canada using Cool Path Duo at 50 W and 45 °C at an irrigation rate of 13 ml/min. The results were compared to historical data from an AFL study which used a six-hole catheter with similar design. RESULTS: A total of 2,725 RF lesions were applied in 188 patients with a mean RF duration of 18.2 ± 11.7 min per procedure. Procedural success was achieved in 96.3 % (181 of 188) acutely and 98.3 % (173 of 176) patients at 3 months. Steam pops occurred in 0.6 % of lesions (15 of 2,725) without coagulum or charring… Compared to the six-hole irrigated tip catheter, the Cool Path Duo catheter delivered more power (33.8 ± 5.9 vs. 29.7 ± 5.2 W, p < 0.0001) at a lower average tip temperature (34.7 ± 1.5 vs. 37.2 ± 2.1 °C, p < 0.0001) with no statistical differences in either 3-month AFL recurrence or complications. CONCLUSION: Cool Path Duo™ irrigated tip catheter is safe and effective in treating typical AFL. When compared to a six-hole irrigated tip catheter, the Cool Path Duo catheter delivers more power at a lower temperature.

The diagnosis of cardiac arrhythmias: a prospective multi-center randomized study comparing mobile cardiac outpatient telemetry versus standard loop event monitoring.

INTRODUCTION: Ambulatory electrocardiographic monitoring systems are frequently used in the outpatient evaluation of symptoms suggestive of a cardiac arrhythmia; however, they have a low yield in the identification of clinically significant but infrequent, brief, and/or intermittently symptomatic arrhythmias. The purpose of this study was to compare the relative value of a mobile cardiac outpatient telemetry system (MCOT) with a patient-activated external looping event monitor (LOOP) for symptoms thought to be due to an arrhythmia. METHODS AND RESULTS: The study was a 17-center prospective clinical trial with patients randomized to either LOOP or MCOT for up to 30 days. Subjects with symptoms of syncope, presyncope, or severe palpitations who had a nondiagnostic 24-hour Holter monitor were randomized. The primary endpoint was the confirmation or exclusion of a probable arrhythmic cause of their symptoms. A total of 266 patients who completed the monitoring period were analyzed. A diagnosis was made in 88% of MCOT subjects compared with 75% of LOOP subjects (P = 0.008). In a subgroup of patients presenting with syncope or presyncope, a diagnosis was made in 89% of MCOT subjects versus 69% of LOOP subjects (P = 0.008). MCOT was superior in confirming the diagnosis of clinical significant arrhythmias, detecting such events in 55 of 134 patients (41%) compared with 19 of 132 patients (15%) in the LOOP group (P < 0.001). CONCLUSIONS: MCOT provided a significantly higher yield than standard cardiac loop recorders in patients with symptoms suggestive of a significant cardiac arrhythmia.

First experience with a Mobile Cardiac Outpatient Telemetry (MCOT) system for the diagnosis and management of cardiac arrhythmia.

Recently, a mobile cardiac outpatient telemetry (MCOT) system has become available that monitors the electrocardiogram continuously, recognizes arrhythmias automatically, and transmits abnormal rhythms instantaneously. MCOT does not require activation by the patient. We report data from the first 100 consecutive patients monitored by this new technology.