Incremental Benefit of Stepwise Nonpulmonary Vein Trigger Provocation During Catheter Ablation of Atrial Fibrillation.

BACKGROUND: The importance of nonpulmonary vein (PV) triggers for the initiation/recurrence of atrial fibrillation (AF) is well established. OBJECTIVES: This study sought to assess the incremental benefit of provocative maneuvers for identifying non-PV triggers. METHODS: We included consecutive patients undergoing first-time AF ablation between 2020 and 2022. The provocation protocol included step 1, identification of spontaneous non-PV triggers after cardioversion of AF and/or during sinus rhythm; step 2, isoproterenol infusion (3, 6, 12, and 20-30 µg/min); and step 3, atrial burst pacing to induce AF followed by cardioversion during residual or low-dose isoproterenol infusion or induce focal atrial tachycardia. Non-PV triggers were defined as non-PV ectopic beats triggering AF or sustained focal atrial tachycardia. RESULTS: Of 1,372 patients included, 883 (64.4%) underwent the complete stepwise provocation protocol with isoproterenol infusion and burst pacing, 334 (24.3%) isoproterenol infusion only, 77 (5.6%) burst pacing only, and 78 (5.7%) no provocative maneuvers (only step 1). Overall, 161 non-PV triggers were found in 135 (9.8%) patients. Of these, 51 (31.7%) non-PV triggers occurred spontaneously, and the remaining 110 (68.3%) required provocative maneuvers for induction. Among those receiving the complete stepwise provocation protocol, there was a 2.2-fold increase in the number of patients with non-PV triggers after isoproterenol infusion, and the addition of burst pacing after isoproterenol infusion led to a total increase of 3.6-fold with the complete stepwise provocation protocol. CONCLUSIONS: The majority of non-PV triggers require provocative maneuvers for induction. A stepwise provocation protocol consisting of isoproterenol infusion followed by burst pacing identifies a 3.6-fold higher number of patients with non-PV triggers.

Innovative approaches to atrial fibrillation prediction: should polygenic scores and machine learning be implemented in clinical practice?

Atrial fibrillation (AF) prediction and screening are of important clinical interest because of the potential to prevent serious adverse events. Devices capable of detecting short episodes of arrhythmia are now widely available. Although it has recently been suggested that some high-risk patients with AF detected on implantable devices may benefit from anticoagulation, long-term management remains challenging in lower-risk patients and in those with AF detected on monitors or wearable devices as the development of clinically meaningful arrhythmia burden in this group remains unknown. Identification and prediction of clinically relevant AF is therefore of unprecedented importance to the cardiologic community. Family history and underlying genetic markers are important risk factors for AF. Recent studies suggest a good predictive ability of polygenic risk scores, with a possible additive value to clinical AF prediction scores. Artificial intelligence, enabled by the exponentially increasing computing power and digital data sets, has gained traction in the past decade and is of increasing interest in AF prediction using a single or multiple lead sinus rhythm electrocardiogram. Integrating these novel approaches could help predict AF substrate severity, thereby potentially improving the effectiveness of AF screening and personalizing the management of patients presenting with conditions such as embolic stroke of undetermined source or subclinical AF. This review presents current evidence surrounding deep learning and polygenic risk scores in the prediction of incident AF and provides a futuristic outlook on possible ways of implementing these modalities into clinical practice, while considering current limitations and required areas of improvement.

Long-Term Freedom From Ventricular Arrhythmias in ARVC With Endocardial Only Ablation: Predictors of Success.

BACKGROUND: Although the epicardial predominance of substrate abnormalities has been well demonstrated in early stages of arrhythmogenic right ventricular cardiomyopathy (ARVC), endocardial (ENDO) ablation may suffice to eliminate ventricular tachycardia (VT) in some patients. OBJECTIVES: This study aimed to report the long-term outcomes of ENDO-only ablation in ARVC patients and factors that predict VT-free survival. METHODS: We included consecutive patients with Task Force Criteria diagnosis of ARVC undergoing a first ENDO-only VT ablation between 1998 and 2020. Ablation was predominantly guided by activation/entrainment mapping for mappable VTs and pace mapping/targeting abnormal electrograms for unmappable VTs. The primary endpoint was freedom from any recurrent sustained VT after the last ENDO-only ablation. RESULTS: Seventy-four ARVC patients underwent ENDO-only VT ablation. VT noninducibility was achieved in 49 (66%) patients. During median follow-up of 6.6 years (Q1-Q3: 3.4-11.2 years), 40 (54.1%) patients remained free from any VT recurrence with rare VT ≤2 episodes in additional 12.2%. Among patients with noninducibility, VT-free survival was 75.5% during long-term follow-up. In multivariable analysis, >45 y of age at diagnosis (HR: 0.41; 95% CI: 0.17-0.98) and VT noninducibility (HR: 0.36; 95% CI: 0.16-0.80) were predictors of VT-free survival. CONCLUSIONS: Long-term VT-free survival can be achieved in over half of ARVC patients following ENDO-only VT ablation, increasing to over 75% if VT noninducibility is achieved. Our results support consideration of a stepwise ENDO-only approach before proceeding to epicardial ablation if VT noninducibility can be achieved particularly in older patients.

Patient-specific quantification of cardiorespiratory motion for cardiac stereotactic radioablation treatment planning.

Background: Cardiac radioablation is a new treatment for patients with refractory ventricular tachycardia (VT). The target for cardiac radioablation is subject to cardiorespiratory motion (CRM), the heart's movement with breathing and cardiac contraction. Data regarding the magnitude of target CRM are limited but are highly important for treatment planning. Objectives: The study sought to assess CRM amplitude by using ablation catheter geometrical data. Methods: Electroanatomic mapping data of patients undergoing catheter ablation for VT at 3 academic centers were exported. The spatial position of the ablation catheter as a function of time while in contact with endocardium was analyzed and used to quantify CRM. Results: Forty-four patients with ischemic and nonischemic cardiomyopathy and VT contributed 1364 ablation lesions to the analysis. Average cardiac and respiratory excursion were 1.62 ± 1.21 mm and 12.12 ± 4.10 mm, respectively. The average ratio of respiratory to cardiac motion was approximately 11:1. CRM was greatest along the craniocaudal axis (9.66 ± 4.00 mm). Regional variations with respect to respiratory and cardiac motion were observed: basal segments had smaller displacements vs midventricular and apical segments. Patient characteristics (previous cardiac surgery, height, weight, body mass index, and left ventricular ejection fraction) had a statistically significant, albeit clinically moderate, impact on CRM. Conclusion: CRM is primarily determined by respiratory displacement and is modulated by the location of the target and the patient's biometric characteristics. The patient-specific quantification of CRM may allow to decrease treatment volume and reduce radiation exposure of surrounding organs at risk while delivering the therapeutic dose to the target.

Sudden Death Risk Assessment in Hypertrophic Cardiomyopathy Across the Lifespan: Reconciling the American and European Approaches.

Hypertrophic cardiomyopathy (HCM) is the most prevalent inherited cardiac disease. Since the modern description of HCM more than seven decades ago, great focus has been placed on preventing its most catastrophic complication: sudden cardiac death (SCD). Implantable cardioverter-defibrillators (ICD) have been recognized to provide effective prophylactic therapy. Over the years, two leading societies, the European Society of Cardiology (ESC) and the American Heart Association/American College of Cardiology (AHA/ACC), have proposed risk stratification models to assess SCD in adults. European guidelines rely on a risk calculator, the HCM Risk-SCD, while American guidelines propose a stand-alone risk factor approach. Recently, risk prediction models were also developed in the pediatric population. This article reviews the latest recommendations on the risk stratification of SCD in HCM and summarises current indications for ICD use.

Procedure-Related Complications of Catheter Ablation for Atrial Fibrillation.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) is a commonly performed procedure. However, it is associated with potentially significant complications. Reported procedure-related complication rates are highly variable, depending in part on study design. OBJECTIVES: The purpose of this systematic review and pooled analysis was to determine the rate of procedure-related complications associated with catheter ablation of AF using data from randomized control trials and to assess temporal trends. METHODS: MEDLINE and EMBASE databases were searched from January 2013 to September 2022 for randomized control trials that included patients undergoing a first ablation procedure of AF using either radiofrequency or cryoballoon (PROSPERO, CRD42022370273). RESULTS: A total of 1,468 references were retrieved, of which 89 studies met inclusion criteria. A total of 15,701 patients were included in the current analysis. Overall and severe procedure-related complication rates were 4.51% (95% CI: 3.76%-5.32%) and 2.44% (95% CI: 1.98%-2.93%), respectively. Vascular complications were the most frequent type of complication (1.31%). The next most common complications were pericardial effusion/tamponade (0.78%) and stroke/transient ischemic attack (0.17%). The procedure-related complication rate during the most recent 5-year period of publication was significantly lower than during the earlier 5-year period (3.77% vs 5.31%; P = 0.043). The pooled mortality rate was stable over the 2 time periods (0.06% vs 0.05%; P = 0.892). There was no significant difference in complication rate according to pattern of AF, ablation modality, or ablation strategies beyond pulmonary vein isolation. CONCLUSIONS: Procedure-related complications and mortality rates associated with catheter ablation of AF are low and have declined in the past decade.

Cerebral thromboembolic risk in atrial fibrillation ablation: a direct comparison of vitamin K antagonists versus non-vitamin K-dependent oral anticoagulants.

PURPOSE: Cerebral thromboembolic events are well-known complications of pulmonary vein isolation (PVI) and can manifest as stroke or silent cerebral embolic lesions. The aim of this study was to compare the incidence of cerebral embolic lesions (including silent cerebral embolism and stroke) after AF ablation in patients on vitamin K antagonists versus patients on non-vitamin K-dependent oral anticoagulants, and to identify corresponding clinical and procedural risk factors. METHODS: A total of 421 patients undergoing PVI were prospectively included into the study. Of these, 43.7% were on VKA and 56.3% on NOAC treatment (dabigatran, rivaroxaban, apixaban, and edoxaban). In the NOAC group, 38% of patients had an interruption of anticoagulation for 24-36 h. All patients underwent pre- and postprocedural cerebral magnetic resonance imaging. RESULTS: Periprocedural cerebral lesions occurred in 13.1% overall. Of these, three (0.7%) resulted in symptomatic cerebrovascular accidents and 52 (12.4%) in silent cerebral embolic lesions. Incidence of cerebral lesions was significantly higher in patients on NOAC compared with VKA (16% vs. 9.2%, respectively, p = 0.04), and in patients who had intraprocedural cardioversions compared with no cardivoersions (19.5% vs. 10.4%, respectively, p = 0.03). In multivariate analysis, both parameters were found to be independent risk factors for cerebral embolism. No significant difference between interrupted and uninterrupted NOAC administration could be detected. CONCLUSIONS: In patients undergoing AF ablation, we identified the use of NOAC and intraprocedural cardioversion as independent risk factors for the occurrence of periprocedural cerebral embolic lesions.