Infra-Hisian Conduction Disturbance and Alternating Left Anterior/Posterior Fascicular Block.

We present an unusual case of alternating left anterior and left posterior fascicular block. Given the known risk for progression to complete atrioventricular block with alternating right bundle and left bundle branch block, we performed an electrophysiological study. Findings were consistent with infra-Hisian disease, and the patient underwent pacemaker implantation.

Characterizing cardiac contractile motion for noninvasive radioablation of ventricular tachycardia.

Background: Respiratory motion management strategies are used to minimize the effects of breathing on the precision of stereotactic ablative radiotherapy for ventricular tachycardia, but the extent of cardiac contractile motion of the human heart has not been systematically explored. Objective: We aim to assess the magnitude of cardiac contractile motion between different directions and locations in the heart. Methods: Patients with intracardiac leads or valves who underwent 4-dimensional cardiac computed tomography (CT) prior to a catheter ablation procedure for atrial or ventricular arrhythmias at 2 medical centers were studied retrospectively. The displacement of transvenous right atrial appendage, right ventricular (RV) implantable cardioverter-defibrillator, coronary sinus lead tips, and prosthetic cardiac devices across the cardiac cycle were measured in orthogonal 3-dimensional views on a maximal-intensity projection CT reconstruction. Results: A total of 31 preablation cardiac 4-dimensional cardiac CT scans were analyzed. The LV lead tip had significantly greater motion compared with the RV lead in the anterior-posterior direction (6.0 ± 2.2 mm vs 3.8 ± 1.7 mm; P = .01) and superior-inferior direction (4.4 ± 2.9 mm vs 3.5 ± 2.0 mm; P = .049). The prosthetic aortic valves had the least movement of all fiducials, specifically compared with the RV lead tip in the left-right direction (3.2 ± 1.2 mm vs 6.1 ± 3.8 mm, P = .04) and the LV lead tip in the anterior-posterior direction (3.8 ± 1.7 mm vs 6.0 ± 2.2 mm, P = .03). Conclusion: The degree of cardiac contractile motion varies significantly (1 mm to 15.2 mm) across different locations in the heart. The effect of contractile motion on the precision of radiotherapy should be assessed on a patient-specific basis.

Impact of artificial intelligence arrhythmia mapping on time to first ablation, procedure duration, and fluoroscopy use.

INTRODUCTION: Artificial intelligence (AI) ECG arrhythmia mapping provides arrhythmia source localization using 12-lead ECG data; whether this information impacts procedural efficiency is unknown. We performed a retrospective, case-control study to evaluate the hypothesis that AI ECG mapping may reduce time to ablation, procedural duration, and fluoroscopy. MATERIALS AND METHODS: Cases in which system output was used were retrospectively enrolled according to IRB-approved protocols at each site. Matched control cases were enrolled in reverse chronological order beginning on the last day for which the technology was unavailable. Controls were matched based upon physician, institution, arrhythmia, and a predetermined complexity rating. Procedural metrics, fluoroscopy data, and clinical outcomes were assessed from time-stamped medical records. RESULTS: The study group consisted of 28 patients (age 65 ± 11 years, 46% female, left atrial dimension 4.1 ± 0.9 cm, LVEF 50 ± 18%) and was similar to 28 controls. The most common arrhythmia types were atrial fibrillation (n = 10), premature ventricular complexes (n = 8), and ventricular tachycardia (n = 6). Use of the system was associated with a 19.0% reduction in time to ablation (133 ± 48 vs. 165 ± 49 min, p = 0.02), a 22.6% reduction in procedure duration (233 ± 51 vs. 301 ± 83 min, p < 0.001), and a 43.7% reduction in fluoroscopy (18.7 ± 13.3 vs. 33.2 ± 18.0 min, p < 0.001) versus controls. At 6 months follow-up, arrhythmia-free survival was 73.5% in the study group and 63.3% in the control group (p = 0.56). CONCLUSION: Use of forward-solution AI ECG mapping is associated with reductions in time to first ablation, procedure duration, and fluoroscopy without an adverse impact on procedure outcomes or complications.

Predicting Major Adverse Events in Patients Undergoing Transcatheter Left Atrial Appendage Occlusion.

BACKGROUND: The National Cardiovascular Data Registry Left Atrial Appendage Occlusion Registry (LAAO) includes the vast majority of transcatheter LAAO procedures performed in the United States. The objective of this study was to develop a model predicting adverse events among patients undergoing LAAO with Watchman FLX. METHODS: Data from 41 001 LAAO procedures with Watchman FLX from July 2020 to September 2021 were used to develop and validate a model predicting in-hospital major adverse events. Randomly selected development (70%, n=28 530) and validation (30%, n=12 471) cohorts were analyzed with 1000 bootstrapped samples, using forward stepwise logistic regression to create the final model. A simplified bedside risk score was also developed using this model. RESULTS: Increased age, female sex, low preprocedure hemoglobin, no prior attempt at atrial fibrillation termination, and increased fall risk most strongly predicted in-hospital major adverse events and were included in the final model along with other clinically relevant variables. The median in-hospital risk-standardized adverse event rate was 1.50% (range, 1.03%-2.84%; interquartile range, 1.42%-1.64%). The model demonstrated moderate discrimination (development C-index, 0.67 [95% CI, 0.65-0.70] and validation C-index, 0.66 [95% CI, 0.62-0.70]) with good calibration. The simplified risk score was well calibrated with risk of in-hospital major adverse events ranging from 0.26% to 3.90% for a score of 0 to 8, respectively. CONCLUSIONS: A transcatheter LAAO risk model using National Cardiovascular Data Registry and LAAO Registry data can predict in-hospital major adverse events, demonstrated consistency across hospitals and can be used for quality improvement efforts. A simple bedside risk score was similarly predictive and may inform shared decision-making.

Pulsed Field Ablation Index-Guided Ablation for Lesion Formation: Impact of Contact Force and Number of Applications in the Ventricular Model.

BACKGROUND: The effect of contact force (CF) on lesion formation is not clear during pulsed field ablation (PFA). The aim of this study was to evaluate the impact of CF, PFA, and their interplay through the PFA index (PF index) formula on the ventricular lesion size in swine. METHODS: PFA was delivered through the CF-sensing OMNYPULSE catheter. Predefined PFA applications (×3, ×6, ×9, and ×12) were delivered maintaining low (5-25 g), high (26-50 g), and very high (51-80 g) CFs. First, PFA lesions were evaluated on necropsy in 11 swine to investigate the impact of CF/PFA-and their integration in the PF index equation-on lesion size (study characterization). Then, 3 different PF index thresholds-300, 450, and 600-were tested in 6 swine to appraise the PF index accuracy to predict the ventricular lesion depth (study validation). RESULTS: In the study characterization data set, 111 PFA lesions were analyzed. CF was 32±17 g. The average lesion depth and width were 3.5±1.2 and 12.0±3.5 mm, respectively. More than CF and PFA dose alone, it was their combined effect to impact lesion depth through an asymptotically increasing relationship. Likewise, not only was the PF index related to lesion depth in the study validation data set (r2=0.66; P<0.001) but it also provided a prediction accuracy of the observed depth of ±2 mm in 69/73 lesions (95%). CONCLUSIONS: CF and PFA applications play a key role in lesion formation during PFA. Further studies are required to evaluate the best PFA ablation settings to achieve transmural lesions.

Pulsed field ablation versus thermal energy ablation for atrial fibrillation: a systematic review and meta-analysis of procedural efficiency, safety, and efficacy.

BACKGROUND: Pulsed field ablation (PFA) induces cell death through electroporation using ultrarapid electrical pulses. We sought to compare the procedural efficiency characteristics, safety, and efficacy of ablation of atrial fibrillation (AF) using PFA compared with thermal energy ablation. METHODS: We performed an extensive literature search and systematic review of studies that compared ablation of AF with PFA versus thermal energy sources. Risk ratio (RR) 95% confidence intervals (CI) were measured for dichotomous variables and mean difference (MD) 95% CI were measured for continuous variables, where RR < 1 and MD < 0 favor the PFA group. RESULTS: We included 6 comparative studies for a total of 1012 patients who underwent ablation of AF: 43.6% with PFA (n = 441) and 56.4% (n = 571) with thermal energy sources. There were significantly shorter procedures times with PFA despite a protocolized 20-min dwell time (MD - 21.95, 95% CI - 33.77, - 10.14, p = 0.0003), but with significantly longer fluroscopy time (MD 5.71, 95% CI 1.13, 10.30, p = 0.01). There were no statistically significant differences in periprocedural complications (RR 1.20, 95% CI 0.59-2.44) or recurrence of atrial tachyarrhythmias (RR 0.64, 95% CI 0.31, 1.34) between the PFA and thermal ablation cohorts. CONCLUSIONS: Based on the results of this meta-analysis, PFA was associated with shorter procedural times and longer fluoroscopy times, but no difference in periprocedural complications or rates of recurrent AF when compared to ablation with thermal energy sources. However, larger randomized control trials are needed.

Frailty and associated outcomes in patients undergoing percutaneous left atrial appendage occlusion: findings from the NCDR LAAO registry.

BACKGROUND: Frailty is associated with significant morbidity and mortality and may have clinical implications in an advanced age population with atrial fibrillation undergoing left atrial appendage occlusion (LAAO). We sought to develop a novel frailty scale to predict worse outcomes in patients undergoing LAAO. METHODS: Patients in the NCDR LAAO Registry between 2016 and 2021 receiving percutaneous LAAO devices were categorized as non-frail (0 points), pre-frail (1-3 points), or frail (4-5 points) based on a 5-point scale representing multiple domains of frailty: hemoglobin <13.0 g/dL in male, <12.0 g/dL in female; creatinine ≥1.2 mg/dL; albumin <3.5 g/dL; body mass index <20 kg/m2; and increased risk of falls. RESULTS: Of 57,728 patients, 44,360 (76.8%) were pre-frail and 7693 (13.3%) were frail. Compared to non-frail, pre-frail and frail patients were older, had a higher burden of co-morbidities, and more disability based on the Modified Rankin Scale. Compared to non-frail patients after adjustment, frail patients were at higher risk of in-hospital major complication (OR 1.29, 95% 1.02-1.62, p = 0.01), any complication (OR 1.29, 95% CI 1.09-1.52, p = 0.0005), and death (OR 5.79, 95% CI 1.75-19.17, p = 0.001), while no difference was observed in pre-frail patients. At 45-day follow-up, there was no difference in the risk of complications in frail patients as compared to non-frail, although mortality was significantly higher (OR 3.01, 95% CI 1.97-4.85, p < 0.0001). CONCLUSION: A simple and practical frailty scale accurately predicts adverse events in patients undergoing LAAO. The 13% of patients considered frail were at significantly higher risk of in-hospital adverse events and 45-day mortality.

Stroke Prevention in Atrial Fibrillation: Our Current Failures and Required Research.

Nonvalvular atrial fibrillation is a common rhythm disorder of middle-aged to older adults that can cause ischemic strokes and systemic embolism. Lifelong use of oral anticoagulants reduces the risk of these ischemic events but increases the risk of major and clinically relevant hemorrhages. These medications also require strict compliance for efficacy, and they have nontrivial failure rates in higher-risk patients. Left atrial appendage closure is a nonpharmacological method to prevent ischemic strokes in atrial fibrillation without the need for lifelong anticoagulant use, but this procedure has the potential for complications and residual embolic events. This workshop of the Roundtable of Academia and Industry for Stroke Prevention discussed future research needed to further decrease the ischemic and hemorrhagic risks among patients with atrial fibrillation. A direct thrombin inhibitor, factor Xa inhibitors, and left atrial appendage closure are FDA-approved approaches whereas factor XIa inhibitors are currently being studied in phase 3 randomized controlled trials for stroke prevention. The benefits, risks, and shortcomings of these treatments and future research required in different high-risk patient populations are reviewed in this consensus statement.

DAPT Is Comparable to OAC Following LAAC With WATCHMAN FLX: A National Registry Analysis.

BACKGROUND: Left atrial appendage occlusion (LAAO) is an approved alternative for stroke prevention in atrial fibrillation for patients with an "appropriate rationale" to avoid long-term oral anticoagulation (OAC). Many patients undergoing LAAO are at high risk of bleeding. OBJECTIVES: This study sought to investigate whether dual antiplatelet therapy (DAPT) is a safe alternative to OAC (direct oral anticoagulation [DOAC] or warfarin) with aspirin after LAAO. METHODS: Using National Cardiovascular Data Registry LAAO registry data, patients undergoing Watchman FLX (Boston Scientific) implantation (August 5, 2020-September 30, 2021) were included in 1:1 propensity-matched analyses comparing discharge medication regimens (DAPT, DOAC/aspirin, or warfarin/aspirin). A composite endpoint (death, stroke, major bleeding, and systemic embolism), its components, and device-related thrombus between discharge and 45 days were evaluated. RESULTS: In 49,968 patients implanted with the Watchman FLX during the study period, the mean age was 77 years, and 40% were women. Postimplant DOAC/aspirin was prescribed in 24,497 patients, warfarin/aspirin in 3,913, and DAPT in 4,155. DAPT patients had more comorbid conditions than patients receiving OAC/aspirin. After propensity score matching, the 45-day composite endpoint rates were similar among the groups (DAPT = 3.44% vs DOAC/aspirin: 4.06%; P = 0.13 and DAPT = 3.23% vs warfarin/aspirin: 3.08%; P = 0.75). Death, stroke, and device-related thrombus were also similar; major bleeding was slightly increased in DOAC/aspirin patients (DAPT = 2.48% vs DOAC/aspirin = 3.25%; P = 0.04 and DAPT = 2.25% vs warfarin/aspirin = 2.22%; P = 0.93). CONCLUSIONS: In a large registry, DAPT had a similar safety profile compared with current Food and Drug Administration-approved postimplant drug regimens of OAC with aspirin following LAAO with the Watchman FLX. Shared decision making for nonpharmacologic stroke prevention should include a discussion of postprocedure medical therapy options.

Safety and acute efficacy of catheter ablation for atrial fibrillation with pulsed field ablation vs thermal energy ablation: A meta-analysis of single proportions.

Background: Pulsed field ablation (PFA) has emerged as a novel energy source for the ablation of atrial fibrillation (AF) using ultrarapid electrical pulses to induce cell death via electroporation. Objective: The purpose of this study was to compare the safety and acute efficacy of ablation for AF with PFA vs thermal energy sources. Methods: We performed an extensive literature search and systematic review of studies that evaluated the safety and efficacy of ablation for AF with PFA and compared them to landmark clinical trials for ablation of AF with thermal energy sources. Freeman-Tukey double arcsine transformation was used to establish variance of raw proportions followed by the inverse with the random-effects model to combine the transformed proportions and generate the pooled prevalence and 95% confidence interval (CI). Results: We included 24 studies for a total of 5203 patients who underwent AF ablation. Among these patients, 54.6% (n = 2842) underwent PFA and 45.4% (n = 2361) underwent thermal ablation. There were significantly fewer periprocedural complications in the PFA group (2.05%; 95% CI 0.94-3.46) compared to the thermal ablation group (7.75%; 95% CI 5.40-10.47) (P = .001). When comparing AF recurrence up to 1 year, there was a statistically insignificant trend toward a lower prevalence of recurrence in the PFA group (14.24%; 95% CI 6.97-23.35) compared to the thermal ablation group (25.98%; 95% CI 15.75-37.68) (P = .132). Conclusion: Based on the results of this meta-analysis, PFA was associated with lower rates of periprocedural complications and similar rates of acute procedural success and recurrent AF with up to 1 year of follow-up compared to ablation with thermal energy sources.

Intracardiac vs Transesophageal Echocardiography for Left Atrial Appendage Occlusion With Watchman FLX in the U.S.

BACKGROUND: Intraprocedural imaging is critical for device delivery in transcatheter left atrial appendage occlusion (LAAO). Although pivotal trials of LAAO devices were conducted using transesophageal echocardiography (TEE), intracardiac echocardiography (ICE) is an emerging imaging modality. OBJECTIVES: This study compared outcomes after ICE- and TEE-guided Watchman FLX implantation in the SURPASS (SURveillance Post Approval AnalySiS Plan) nationwide LAAO registry. METHODS: Baseline characteristics were compared using chi-square and t-tests. Outcomes were reported in unadjusted and adjusted comparisons via propensity weighting. RESULTS: Between August 2020 and September 2021, LAAO was attempted in 39,759 patients at 698 sites, including 2,272 cases (5.7%) with ICE and 31,835 (80.0%) with TEE. ICE and TEE patients had similar baseline characteristics and mean procedural times (ICE 82 minutes vs TEE 78 minutes). ICE patients were less likely to receive general anesthesia (54% vs 98%, P < 0.01). Successful device implantation (98.3% vs 97.6%) and complete seal rates at 45 days were similar (n = 25,280; 83% vs 82%). Most adverse event rates were similar; unadjusted mortality rates at 45 days were 1.1% for ICE vs 0.8% for TEE (P = 0.14), and 1.0% vs 0.7% (P = 0.27) in adjusted analyses. Even after adjustment, pericardial effusion rates requiring intervention were significantly higher with ICE at 45 days (1.0% vs 0.5%; P = 0.02). This rate decreased as operators performed more ICE-guided procedures, although 82% of operators had performed <10 ICE-guided procedures overall. CONCLUSIONS: In the largest comparison to date, ICE use was infrequent. ICE and TEE both achieved high rates of complete LAAO. ICE was associated with significantly higher rates of pericardial effusion requiring intervention.

Safety and efficacy of catheter ablation of atrial fibrillation in the very elderly (≥80 years old): Insights from the UC San Diego AF Ablation Registry.

BACKGROUND: Catheter ablation improves outcomes in symptomatic atrial fibrillation (AF) patients. However, its safety and efficacy in the very elderly (≥80 years old) is not well described. HYPOTHESIS: Ablation of AF in the very elderly is safe and effective. METHODS: We performed a retrospective study of all patients who underwent catheter ablation enrolled in the University of California, San Diego AF Ablation Registry. The primary outcome was freedom from atrial arrhythmias on or off antiarrhythmic drugs (AADs). RESULTS: Of 847 patients, 42 (5.0%) were 80 years of age or greater with a median age of 81.5 (80-82.3) and 805 (95.0%) were less than 80 years of age with a median age of 64.4 (57.6-70.2). Among those who were ≥80 years old, 29 were undergoing de novo ablation (69.0%), whereas in the younger cohort, 518 (64.5%) were undergoing de novo ablation (p = .548). There were no statistically significant differences in fluoroscopy (p = .406) or total procedure times (p = .076), AAD use (p = .611), or procedural complications (p = .500) between groups. After multivariable adjustment, there were no statistically significant differences in recurrence of any atrial arrhythmias on or off AAD (adjusted hazard ratio [AHR]: 0.75; 95% confidence interval [CI]: 0.45-1.23; p = .252), all-cause hospitalizations (AHR: 0.86; 95% CI: 0.46-1.60; p = .626), or all-cause mortality (AHR: 4.48; 95% CI: 0.59-34.07; p = .147) between the very elderly and the younger cohort. CONCLUSION: In this registry analysis, catheter ablation of AF appears similarly effective and safe in patients 80 years or older when compared to a younger cohort.

In-hospital complications associated with pulmonary vein isolation with adjunctive lesions: the NCDR AFib Ablation Registry.

AIMS: No prior study has been adequately powered to evaluate real-world safety outcomes in those receiving adjunctive ablation lesions beyond pulmonary vein isolation (PVI). We sought to evaluate characteristics and in-hospital complications among patients undergoing PVI with and without adjunctive lesions. METHODS AND RESULTS: Patients in the National Cardiovascular Data Registry AFib Ablation Registry undergoing first-time atrial fibrillation (AF) ablation between 2016 and 2020 were identified and stratified into paroxysmal (PAF) and persistent AF, and separated into PVI only, PVI + cavotricuspid isthmus (CTI) ablation, and PVI + adjunctive (superior vena cava isolation, coronary sinus, vein of Marshall, atypical atrial flutter lines, other). Adjusted odds of adverse events were calculated using multivariable logistic regression. A total of 50 937 patients [PAF: 30 551 (60%), persistent AF: 20 386 (40%)] were included. Among those with PAF, there were no differences in the adjusted odds of complications between PVI + CTI or PVI + adjunctive when compared with PVI only. Among persistent AF, PVI + adjunctive was associated with a higher risk of any complication [3.0 vs. 4.5%, odds ratio (OR) 1.30, 95% confidence interval (CI) 1.07-1.58] and major complication (0.8 vs. 1.4%, OR 1.56, 95% CI 1.10-2.21), while no differences were observed in PVI + CTI compared with PVI only. Overall, there was high heterogeneity in adjunctive lesion type, and those receiving adjunctive lesions had a higher comorbidity burden. CONCLUSION: Additional CTI ablation was common without an increased risk of complications. Adjunctive lesions other than CTI are commonly performed in those with more comorbidities and were associated with an increased risk of complications in persistent AF, although the current analysis is limited by high heterogeneity in adjunctive lesion set type.

Initial Findings From the National Cardiovascular Data Registry of Atrial Fibrillation Ablation Procedures.

BACKGROUND: The National Cardiovascular Data Registry (NCDR) AFib Ablation Registry was created to assess real-world prevalence, demographic characteristics, procedural management, and outcomes of patients undergoing atrial fibrillation (AF) ablation procedures. OBJECTIVES: The goal of this study was to characterize the patient, hospital, and physician characteristics and in-hospital outcomes related to AF ablation in the first 5 years of the registry. METHODS: This paper describes the AFib Ablation Registry structure and governance, outcome assessment processes, data quality, and data collection processes. The characteristics of the patient population, hospitals, and in-hospital outcomes are also described. RESULTS: A total of 76,219 patients were included in the registry between January 2016 and December 2020 (mean age 65.5 ± 10.3 years, 65.2% male, 55.8% paroxysmal AF, mean CHA2DS2-VASc score 2.7 ± 1.6) treated by 708 physicians in 162 hospitals. Successful isolation of all pulmonary veins was achieved in 92.4% of patients. The prevalence of any complication during procedural admission was 2.50% and major complication was 0.9%, including significant bradycardia in 0.47%, heart failure in 0.47%, and pericardial effusion requiring intervention in 0.44%. Hospitalization >1 day occurred in 11.8% of patients, and in-hospital death was rare (n = 41 [0.05%]). CONCLUSIONS: The NCDR AFib Ablation Registry is the largest multicenter, prospective cohort study of patients undergoing catheter ablation worldwide. Results in the first 5 years showed that successful pulmonary vein isolation is achieved in the majority of patients, with a low rate of complications. Future studies from the registry will assess practice trends, evaluate treatment patterns associated with different patient outcomes, and support development of evidence-based guidelines.