Acute and long-term results with the 3rd generation visually guided laser balloon ablation system for pv isolation.

BACKGROUND: Visually guided laser balloon ablation is known as an effective pulmonary vein (PV) isolation device. The third-generation laser balloon ablation system (X3) equipped with compliant balloon and an automated motor-driven laser output mechanism, namely RAPID mode, has been clinically proven for PV isolation. METHODS: PV isolation with X3 was performed in all the patients with paroxysmal and early-stage persistent atrial fibrillation (AF). Acute data for PV isolation and clinical outcomes including supraventricular tachyarrhythmia (SVT: AF, atrial flutter, or atrial tachycardia)-free survival rate beyond 1 year were analyzed. RESULTS: A total of 110 patients (62 ± 13 years old, 80% of paroxysmal AF) were treated with X3. RAPID mode with was utilized to achieve PV isolation in all cases. In combination with RAPID mode and spot mode laser ablation, 91.1% (380/417) of veins were isolated on the first circumferential lesion set and did not require touch-up ablation and during the index procedure 100% of attempted veins were isolated. The mean procedure time was 77.0 ± 22.7 min and LA dwell time was 61.9 ± 22.0 min. Total duration of laser application was 5.1 ± 2.3 min per vein. At 1 year, SVT-free survival rate was 93.7% in paroxysmal AF patients, and 81.1% in persistent AF patients. CONCLUSIONS: A novel continuous automatic laser balloon ablation system was proved to be safe and effective for both paroxysmal and persistent AF patients. The clinical result demonstrated that PV isolation with X3 could achieve a high SVT-free survival rate.

Pulsed Field Ablation to Treat Atrial Fibrillation: Autonomic Nervous System Effects.

BACKGROUND: During atrial fibrillation ablations using thermal energy, the treatment effect is attributed to not just pulmonary vein isolation (PVI), but also to modulation of the autonomic nervous system by ablation of cardiac ganglionated plexi (GP). OBJECTIVES: This study sought to assess the impact of pulsed field ablation (PFA) on the GP in patients undergoing PVI. METHODS: In the retrospective phase, heart rate was assessed pre- versus post-PVI using PFA, cryoballoon ablation, or radiofrequency ablation. In the prospective phase, a pentaspline PFA catheter was used in a protocol: 1) pre-PFA, high-frequency stimulation (HFS) identified GP sites by vagal effects; 2) PVI was performed assessing for repetitive vagal effects over each set of PF applications; 3) mapping defined PVI extent to identify those GP in the ablation zone; and 4) repeat HFS at GP sites to assess for persistence of vagal effects. RESULTS: Between baseline and 3 months, heart rates in the retrospective radiofrequency ablation (n = 40), cryoballoon (n = 40), and PFA (n = 40) cohorts increased by 8.9 ± 11.4, 11.1 ± 9.4, and -0.1 ± 9.2 beats/min, respectively (P= 0.01 PFA vs radiofrequency ablation; P= 0.01 PFA vs cryoballoon ablation). In the prospective phase, pre-PFA HFS in 20 additional patients identified 65 GP sites. During PFA, vagal effects were noted in 45% of first PF applications, persisting through all applications in 83%. HFS post-PFA reproduced vagal effects in 29 of 38 sites (76%) in low-voltage tissue. CONCLUSIONS: PFA has minimal effect on GP. Unlike with thermal ablation, the mechanism by which PFA treats atrial fibrillation is mediated solely by durable PVI.

Efficacy and safety of novel temperature-controlled radiofrequency ablation system during pulmonary vein isolation in patients with paroxysmal atrial fibrillation: TRAC-AF study.

BACKGROUND AND PURPOSE: Saline-irrigated radiofrequency ablation (RFA) for atrial fibrillation (AF) is limited by the absence of reliable thermal feedback limiting the utility of temperature monitoring for power titration. The DiamondTemp (DT) ablation catheter was designed to allow efficient temperature-controlled irrigated ablation. We sought to assess the 1-year clinical safety and efficacy of the DT catheter in treating drug-refractory paroxysmal AF. METHODS: The TRAC-AF trial (NCT02821351) is a prospective, multi-center (n = 4), single-arm study which enrolled patients with symptomatic, drug-refractory, paroxysmal AF. Using the DT catheter, point-by-point ablation was performed around all pulmonary veins (PVs) to achieve PV isolation (PVI). Ablation was performed in a temperature-controlled mode (60 °C, max 50 W). Acute and chronic efficacy and safety was evaluated. RESULTS: Seventy-one patients (age 69.9 ± 11.0 years; 60.6% male) were ablated using the DT catheter. The mean fluoroscopy and RF ablation times were 9.3 ± 6.1 min and 20.6 ± 8.9 min, respectively. Acute isolation of all PVs was achieved in 100% of patients, and freedom from AF after 1 year was 70.6%. There were no steam pops, char, or coagulum on the catheter tip after ablation. There were few serious procedure/device-related adverse events including a single case of cardiac tamponade (1.4%) and transient ischemic attack (1.4). CONCLUSION: This first in man series demonstrates that temperature-controlled irrigated RFA with the DT catheter is efficient, safe, and effective in the treatment of paroxysmal AF. Randomized controlled trials are ongoing and will evaluate better the role of this catheter in relation to standard RFA. TRIAL REGISTRATION: Registered on the site ClinicalTrials.gov January 2016 with identifier: NCT02821351.

Pulsed Field Ablation of Paroxysmal Atrial Fibrillation: 1-Year Outcomes of IMPULSE, PEFCAT, and PEFCAT II.

OBJECTIVES: This study sought to determine whether durable pulmonary vein isolation (PVI) using pulsed field ablation (PFA) translates to freedom from atrial fibrillation recurrence without an increase in adverse events. BACKGROUND: PFA is a nonthermal ablative modality that, in preclinical studies, is able to preferentially ablate myocardial tissue with minimal effect on surrounding tissues. Herein, we present 1-year clinical outcomes of PFA. METHODS: In 3 multicenter studies (IMPULSE [A Safety and Feasibility Study of the IOWA Approach Endocardial Ablation System to Treat Atrial Fibrillation], PEFCAT [A Safety and Feasibility Study of the FARAPULSE Endocardial Ablation System to Treat Paroxysmal Atrial Fibrillation], and PEFCAT II [Expanded Safety and Feasibility Study of the FARAPULSE Endocardial Multi Ablation System to Treat Paroxysmal Atrial Fibrillation]), paroxysmal atrial fibrillation patients underwent PVI using a basket or flower PFA catheter. Invasive remapping was performed at ∼2 to 3 months, and reconnected PVs were reisolated with PFA or radiofrequency ablation. After a 90-day blanking period, arrhythmia recurrence was assessed over 1-year follow-up. RESULTS: In 121 patients, acute PVI was achieved in 100% of PVs with PFA alone. PV remapping, performed in 110 patients at 93.0 ± 30.1 days, demonstrated durable PVI in 84.8% of PVs (64.5% of patients), and 96.0% of PVs (84.1% of patients) treated with the optimized biphasic energy PFA waveform. Primary adverse events occurred in 2.5% of patients (2 pericardial effusions or tamponade, 1 hematoma); in addition, there was 1 transient ischemic attack. The 1-year Kaplan-Meier estimates for freedom from any atrial arrhythmia for the entire cohort and for the optimized biphasic energy PFA waveform cohort were 78.5 ± 3.8% and 84.5 ± 5.4%, respectively. CONCLUSIONS: PVI with a "single-shot" PFA catheter results in excellent PVI durability and acceptable safety with a low 1-year rate of atrial arrhythmia recurrence. These data mitigate concern that the nonthermal ablative mechanism of PFA might mask undiscovered compromises to clinical success. (IMPULSE: A Safety and Feasibility Study of the IOWA Approach Endocardial Ablation System to Treat Atrial Fibrillation, NCT03700385; A Safety and Feasibility Study of the FARAPULSE Endocardial Ablation System to Treat Paroxysmal Atrial Fibrillation, NCT03714178; PEFCAT II Expanded Safety and Feasibility Study of the FARAPULSE Endocardial Multi Ablation System to Treat Paroxysmal Atrial Fibrillation [PEFCAT II], NCT04170608).

Pivotal Study of a Novel Motor-Driven Endoscopic Ablation System.

[Figure: see text].

Retrieval of Long-Term Implanted Leadless Pacemakers: A Single-Center Experience.

OBJECTIVES: The authors report their single-center experience with the retrieval and replacement of long-term implanted leadless cardiac pacemakers (LPs) and the factors contributing to success. BACKGROUND: LPs are a clinically effective and safe alternative to standard transvenous pacemakers for single-chamber ventricular pacing. However, the feasibility of retrieving and replacing long-term implanted LPs is not well known. METHODS: A total of 34 patients with implanted Nanostim LPs (mean implantation duration 1,570 ± 479 days) subsequently underwent retrieval. On the basis of fluoroscopic imaging, the cohort was divided into 2 groups: those with remarkable swinging movement (SM) of the LP docking button (n = 25) and those without SM (n = 9). RESULTS: The overall LP retrieval success rate was 85% (n = 29). New leadless devices were implanted in 27 patients immediately after LP retrieval. No procedure-related adverse events occurred. The rate of successful LP retrieval was significantly higher in the SM group (25 of 25 [100%]) than in the no-SM group (4 of 9 [44%]) (p < 0.001), and fluoroscopy time during the retrieval procedure was shorter in the SM group (12.7 ± 8.6 min) than in the no-SM group (45.6 ± 19 min) (p < 0.001). CONCLUSIONS: This study demonstrated the feasibility and safety of retrieval of long-term implanted LPs after a mean duration of 4 years. Retrieval was most successful in patients whose docking buttons exhibited significant SM.

His bundle pacing after failure of cardiac resynchronization therapy: a case study.

His bundle pacing is a relatively new method of cardiac pacing. This method is used in patients with atrioventricular block to prevent heart failure associated with right ventricular pacing, and in patients with bundle branch block and cardiomyopathy. We report a patient with cardiomyopathy and left bundle branch block with failure of cardiac resynchronization therapy. Permanent His bundle pacing was associated with clinical improvement and improvement of parameters of cardiac function.

Successful Retrieval of a 4-Year-Old Micra Transcatheter Pacemaker System in a Patient With Leadless Biventricular Pacing Therapy.

This is the first report of the management of a patient with cardiac resynchronization therapy using leadless biventricular pacing. Successful retrieval of a 4-year-old Micra transcatheter pacing system (TPS) and reimplantation of a new Micra TPS prevented device-to-device interactions from multiple pacing devices in the right ventricle. (Level of Difficulty: Advanced.).

Pulsed Field Ablation for Pulmonary Vein Isolation in Atrial Fibrillation.

BACKGROUND: Catheter ablation of atrial fibrillation using thermal energies such as radiofrequency or cryothermy is associated with indiscriminate tissue destruction. During pulsed field ablation (PFA), subsecond electric fields create microscopic pores in cell membranes-a process called electroporation. Among cell types, cardiomyocytes have among the lowest thresholds to these fields, potentially permitting preferential myocardial ablation. OBJECTIVES: The purpose of these 2 trials was to determine whether PFA allows durable pulmonary vein (PV) isolation without damage to collateral structures. METHODS: Two trials were conducted to assess the safety and effectiveness of catheter-based PFA in paroxysmal atrial fibrillation. Ablation was performed using proprietary bipolar PFA waveforms: either monophasic with general anesthesia and paralytics to minimize muscle contraction, or biphasic with sedation because there was minimal muscular stimulation. No esophageal protection strategy was used. Invasive electrophysiological mapping was repeated after 3 months to assess the durability of PV isolation. RESULTS: In 81 patients, all PVs were acutely isolated by monophasic (n = 15) or biphasic (n = 66) PFA with ≤3 min elapsed delivery/patient, skin-to-skin procedure time of 92.2 ± 27.4 min, and fluoroscopy time of 13.1 ± 7.6 min. With successive waveform refinement, durability at 3 months improved from 18% to 100% of patients with all PVs isolated. Beyond 1 procedure-related pericardial tamponade, there were no additional primary adverse events over the 120-day median follow-up, including: stroke, phrenic nerve injury, PV stenosis, and esophageal injury. The 12-month Kaplan-Meier estimate of freedom from arrhythmia was 87.4 ± 5.6%. CONCLUSIONS: In first-in-human trials, PFA preferentially affected myocardial tissue, allowing facile ultra-rapid PV isolation with excellent durability and chronic safety. (IMPULSE: A Safety and Feasibility Study of the IOWA Approach Endocardial Ablation System to Treat Atrial Fibrillation; NCT03700385; and PEFCAT: A Safety and Feasibility Study of the FARAPULSE Endocardial Ablation System to Treat Paroxysmal Atrial Fibrillation; NCT03714178).

Ablation of Atrial Fibrillation With Pulsed Electric Fields: An Ultra-Rapid, Tissue-Selective Modality for Cardiac Ablation.

OBJECTIVES: The authors report the first acute clinical experience of atrial fibrillation ablation with PEF-both epicardial box lesions during cardiac surgery, and catheter-based PV isolation. BACKGROUND: Standard energy sources rely on time-dependent conductive heating/cooling and ablate all tissue types indiscriminately. Pulsed electric field (PEF) energy ablates nonthermally by creating nanoscale pores in cell membranes. Potential advantages for atrial fibrillation ablation include: 1) cardiomyocytes have among the lowest sensitivity of any tissue to PEF-allowing tissue selectivity, thereby minimizing ablation of nontarget collateral tissue; 2) PEF is delivered rapidly over a few seconds; and 3) the absence of coagulative necrosis obviates the risk of pulmonary vein (PV) stenosis. METHODS: PEF ablation was performed using a custom over-the-wire endocardial catheter for percutaneous transseptal PV isolation, and a linear catheter for encircling the PVs and posterior left atrium during concomitant cardiac surgery. Endocardial voltage maps were created pre- and post-ablation. Continuous and categorical data are summarized and presented as mean ± SD and frequencies. RESULTS: At 2 centers, 22 patients underwent ablation under general anesthesia: 15 endocardial and 7 epicardial. Catheter PV isolation was successful in all 57 PVs in 15 patients (100%) using 3.26 ± 0.5 lesions/PV: procedure time 67 ± 10.5 min, catheter time (PEF catheter entry to exit) 19 ± 2.5 min, total PEF energy delivery time <60 s/patient, and fluoroscopy time 12 ± 4.0 min. Surgical box lesions were successful in 6 of 7 patients (86%) using 2 lesions/patient. The catheter time for epicardial ablation was 50.7 ± 19.5 min. There were no complications. CONCLUSIONS: These data usher in a new era of tissue-specific, ultrarapid ablation of atrial fibrillation.

Leadless pacemaker versus transvenous single-chamber pacemaker therapy: A propensity score-matched analysis.

BACKGROUND: The recent introduction of leadless pacemakers (PMs) was aimed to eliminate transvenous lead- and pocket-related complications. While the initial results with the leadless PMs seem promising, the nonrandomized nature, limited implant experience of operators, and short follow-up period of these studies preclude a simple comparison to transvenous PMs. OBJECTIVES: The objective of this study was to provide a balanced comparison of leadless and transvenous single-chamber PM therapies through a propensity score-matched analysis. METHODS: Leadless patients from 3 experienced leadless implant centers were propensity score-matched to VVI-R patients from a contemporary prospective multicenter transvenous PM registry. The primary outcome was device-related complications that required invasive intervention during mid-term follow-up. Separate analyses including and excluding PM advisory-related complications were performed. RESULTS: A total of 635 patients were match-eligible (leadless: n = 254; transvenous: n = 381), of whom 440 patients (median age 78 years; interquartile range 70-84 years; 61% men) were successfully matched (leadless: n = 220 vs transvenous: n = 220). The complication rate at 800 days of follow-up was 0.9% (95% confidence interval [CI] 0%-2.2%) in the leadless group vs 4.7% (95% CI 1.8%-7.6%) in the transvenous group when excluding PM advisory-related complications (P = .02). When including these PM advisory-related complications, the complication rate at 800 days increased to 10.9% (95% CI 4.8%-16.5%) in the leadless group vs 4.7% (95% CI 1.8%-7.6%) in the transvenous group (P = .063). CONCLUSION: This study reveals favorable complication rates for leadless compared to transvenous single-chamber pacing therapy at mid-term follow-up in a propensity score-matched cohort. When including PM advisory-related complications, this advantage is no longer observed.

Laser Balloon or Wide-Area Circumferential Irrigated Radiofrequency Ablation for Persistent Atrial Fibrillation: A Multicenter Prospective Randomized Study.

BACKGROUND: Pulmonary vein isolation is the cornerstone of ablation for persistent atrial fibrillation (AF). The role of balloon catheters in this patient population remains ill defined. We sought to compare efficacy and safety of the laser balloon (LB) with wide-area circumferential pulmonary vein isolation using irrigated radiofrequency current (RF) ablation and 3-dimensional mapping. METHODS AND RESULTS: In 6 European centers, patients with persistent AF were prospectively randomized. Follow-up included 3-day Holter ECG recordings and office visits at 3, 6, and 12 months. The primary efficacy end point was freedom from AF between 90 and 365 days after a single ablation. The primary safety end point was the incidence of any periprocedural complications. Of 152 enrolled patients, 134 (n=68 LB and 66 RF; 63% men; mean age, 66+10 years) with persistent AF (median AF history, 14 months; Q1-Q3, 7-36 months) underwent pulmonary vein isolation and completed the entire follow-up. Baseline parameters were similar in both groups. Procedure and fluoroscopy times were similar in both groups (135±38 and 14±9 minutes (LB) versus 128±51 and 11±9 minutes). The primary efficacy end point was met by 71.2% versus 69.3%, in the LB and RF groups, respectively (P=0.40). In the LB group, stroke (n=1), a false aneurysm (n=1), and phrenic nerve palsy (n=1) were observed. In the RF group, 2 patients developed a false aneurysm, and 1 patient needed surgical repair. CONCLUSIONS: An LB-guided strategy was associated with similar efficacy as wide-area circumferential pulmonary vein isolation using irrigated RF in patients with persistent AF. CLINICAL TRIAL REGISTRATION: https://www.clinicaltrials.org. Unique identifier: NCT01863472.

Left Atrial Appendage Closure Under Intracardiac Echocardiographic Guidance: Feasibility and Comparison With Transesophageal Echocardiography.

BACKGROUND: Transcatheter left atrial appendage closure is an alternative therapy for stroke prevention in atrial fibrillation patients. These procedures are currently guided with transesophageal echocardiography and fluoroscopy in most centers. As intracardiac echocardiography (ICE) is commonly used in other catheter-based procedures, we sought to determine the safety and effectiveness of intracardiac echocardiography-guided left atrial appendage closure with the Watchman device. METHODS AND RESULTS: A total of 27 patients (11 males, 77.0±8.5 years) with atrial fibrillation receiving Watchman left atrial appendage closure under intracardiac echocardiography guidance at a single center were investigated. All patients were implanted successfully. There were no major procedural complications. The overall procedure-related complication rate was 14.8%, mainly due to access site hematoma. Transesophageal echocardiography demonstrated successful closure of the left atrial appendage in all patients at 45 days after device implant. CONCLUSIONS: Transcatheter left atrial appendage closure with intracardiac echocardiography guidance is safe and feasible.

Catheter Ablation of Ischemic Ventricular Tachycardia With Remote Magnetic Navigation: STOP-VT Multicenter Trial.

INTRODUCTION: Catheter ablation is an effective treatment of scar-related ventricular tachycardia (VT), but the overall complexity of the procedure has precluded its widespread use. Remote magnetic navigation (RMN) has been shown to facilitate cardiac mapping and ablation of VT in a retrospective series. STOP-VT is the first multicenter, prospective, single-arm and single-procedure study evaluating RMN-based mapping and ablation of post-infarction VT. METHODS: Patients with documented VT and prior MI, in whom an ICD was implanted either for primary or secondary prevention, were recruited from four EU and US centers. Either a transseptal (48 patients) or transaortic (5 patients) approach was employed to gain access for ventricular endocardial mapping/ablation during VT (entrainment mapping, activation mapping) and/or substrate mapping in sinus rhythm (elimination of fractionated/late potentials, variable extent of substrate modification) with RMN and irrigated RF ablation. The primary endpoints were as follows: (i) non-inducibility of the target VT or any other sustained VT; (ii) elimination of sustained VT/VF during ICD follow-up of up to 12 months. RESULTS: The cohort included 53 consecutive patients (median age 67 years, 49 men, median LVEF 31%). One hemodynamically unstable patient was excluded at the onset of mapping. Inducibility of sustained VT was achieved an average of 2.2 times per patient (1-8), with mean tachycardia cycle length (TCL) 374 milliseconds (179-510). Mean total procedure and fluoroscopy times were 223 minutes and 8.7 minutes, respectively; mean cumulative fluoroscopy time during mapping and ablation was 0.95 minutes; maximum power averaged 42.3 W with nominal saline 30 cc/min irrigation; mean cumulative RF time was 38 minutes. Non-inducibility of the target VT was achieved in 49/52 patients (94.2%) and non-inducibility of any VT was achieved in 38/52 patients (73.1%). A combination of RMN and manual ablation was performed in two patients, rendering one non-inducible. During the 12-month ICD follow-up period, freedom from any sustained VT/VF was observed in 30 patients (62%), of which 19 (63%) were off antiarrhythmic medications. Five patients expired during follow-up: one presented with a VT storm, but for the others, death was not related to VT/VF (MI-cardiogenic shock, pulmonary embolism, bronchogenic carcinoma, end stage heart failure). No procedural complications were reported. CONCLUSIONS: This first prospective, single-procedure, multicenter study indicates that remote magnetic navigation is a safe and effective method for catheter ablation of post-infarction VT.

Anatomical predictors for successful pulmonary vein isolation using balloon-based technologies in atrial fibrillation.

PURPOSE: We evaluated the correlation between pulmonary venous (PV) anatomy and acute and long-term success of PV isolation (PVI) with two balloon-based ablation catheter techniques. METHODS: One hundred consecutive patients were analyzed in two equal groups treated with either the second-generation cryoballoon (CRYO) catheter or the visually guided laser ablation (VGLA) catheter. All patients underwent multi-detector computed tomography (CT) imaging. The primary and secondary efficacy endpoints were the procedural achievement of proven electrical isolation of all veins and freedom from atrial fibrillation (AF) within a 1-year follow-up period, respectively. RESULTS: Variant PV anatomy was observed in 32% of patients in the CRYO group and in 40% of patients in the VGLA group. All PVs were targeted with either the CRYO catheter (n = 199) or the VGLA catheter (n = 206). One hundred ninety-three of 199 PVs (97%) were successfully isolated in the CRYO group and 194 of 206 PVs (94%) in the VGLA group (p = 0.83). Over a 12-month follow-up, AF recurrence was documented in 11/45 (24%) and 7/43 (16%) patients in the CRYO and the VGLA groups, respectively (p = 0.21). In the CRYO group, a larger left inferior PV size was associated with worse long-term outcome (p = 0.001). In the VGLA group, a larger left superior PV size (p = 0.003) and more oval right inferior PV were associated with worse acute success (p = 0.038). There was no absolute cutoff between PV anatomy and clinical success. CONCLUSIONS: The variability of PV anatomy did not significantly compromise acute success of PVI or patient outcomes.

Chronic performance of a leadless cardiac pacemaker: 1-year follow-up of the LEADLESS trial.

BACKGROUND: A leadless cardiac pacemaker (LCP) system was recently introduced to overcome lead-related complications of conventional pacing systems. To date, long-term results of an LCP system are unknown. OBJECTIVES: The aim of this study was to assess the complication incidence, electrical performance, and rate response characteristics within the first year of follow-up of patients implanted with an LCP. METHODS: We retrospectively assessed intermediate-term follow-up data for 31 of 33 patients from the LEADLESS trial cohort who had an indication for single-chamber pacing and received an LCP between December 2012 and April 2013. RESULTS: The mean age of the cohort was 76 ± 8 years, and 65% were male. Between 3 and 12 months of follow-up, there were no pacemaker-related adverse events reported. The pacing performance results at 6- and 12-month follow-up were, respectively, as follows: mean pacing threshold (at a 0.4-ms pulse width), 0.40 ± 0.26 V and 0.43 ± 0.30 V; R-wave amplitude 10.6 ± 2.6 mV and 10.3 ± 2.2 mV; and impedance 625 ± 205 Ω and 627 ± 209 Ω. At the 12-month follow-up in 61% of the patients (n = 19 of 31), the rate response sensor was activated, and an adequate rate response was observed in all patients. CONCLUSIONS: The LCP demonstrates very stable performance and reassuring safety results during intermediate-term follow-up. These results support the use of the LCP as a promising alternative to conventional pacemaker systems. Continued evaluation is warranted to further characterize this system. (Evaluation of a New Cardiac Pacemaker; NCT01700244).