Texas Cardiac Arrhythmia

For patients with atrial fibrillation, the use of oral anticoagulant therapy to prevent stroke is limited by the risk of bleeding. Left atrial appendage closure is considered for patients who are unsuitable candidates for long-term anticoagulation, but its role in patients who are eligible for anticoagulants has not been established. In this ongoing, prospective, international, randomized trial involving patients with atrial fibrillation who were suitable candidates for anticoagulation, we randomly assigned patients in a 1:1 ratio to receive either device-based left atrial appendage closure (device group) or non-vitamin K antagonist oral anticoagulant (NOAC) therapy (anticoagulation group). The primary efficacy end point - a composite of death from cardiovascular causes, stroke, or systemic embolism - was tested for noninferiority (noninferiority margin, 4.8 percentage points) after 3 years of follow-up. The primary safety end point, non-procedure-relatedbleeding, was tested for superiority. Of the 3000 patients who underwent randomization, 1499 were assigned to the device group and 1501 to the anticoagulation group. The mean (±SD) age of the patients was 71.7±7.5 years, 31.9% of the patients were women, and the mean CHA2DS2-VASc score was 3.5±1.3. At 3 years, a primary efficacy end-point event had occurred in 81 patients (Kaplan-Meier estimate, 5.7%) in the device group and in 65 patients (Kaplan-Meier estimate, 4.8%) in the anticoagulation group (difference, 0.9 percentage points; 95% confidence interval [CI], -0.8 to 2.6; P<0.001 for noninferiority). Non-procedure-related bleeding occurred in 154 patients (Kaplan-Meier estimate, 10.9%) in the device group and in 260 patients (Kaplan-Meier estimate, 19.0%) in the anticoagulation group (hazard ratio, 0.55; 95% CI, 0.45 to 0.67; P<0.001 for superiority). Among patients with atrial fibrillation who were candidates for anticoagulation, device-based left atrial appendage closure was noninferior to NOAC therapy with respect to a composite of death from cardiovascular causes, stroke, or systemic embolism and was superior to NOAC therapy for non-procedure-related bleeding at 3 years. (Funded by Boston Scientific; CHAMPION-AF ClinicalTrials.gov number, NCT04394546.).

The optimal anticoagulation strategy for patients with atrial fibrillation (AF) and obstructive hypertrophic cardiomyopathy (oHCM) remains unclear. This study compared the outcomes of direct oral anticoagulants (DOACs) versus warfarin in this patient population. Data from the TriNetX Research Network were used to identify patients with AF and oHCM treated with either DOACs or warfarin. Patients with a prior history of stroke were excluded. Propensity score matching (PSM) was performed to balance baseline characteristics. The primary outcome was ischemic stroke. Secondary outcomes included: all-cause death, all-cause hospitalization, acute myocardial infarction, gastrointestinal bleed, hematuria, and brain hemorrhage. Hazard ratios (HRs) were estimated by Cox proportional hazard models. A total of 7090 patients in the DOAC group and 3350 in the warfarin group were included prior to PSM. Following PSM, each cohort included 3307 patients. The incidence of ischemic stroke was lower in the DOAC group (3.5%) compared with the warfarin group (4.8%), with a hazard ratio (HR) of 0.74 (95% confidence interval [CI]: 0.58-0.95). All-cause mortality was similar between groups, with 555 (16.8%) deaths in the DOAC group and 575 (17.4%) in the warfarin group (HR: 0.996, 95% CI: 0.89-1.12). All-cause hospitalization rates were lower in the DOAC group (64.5%) compared with the warfarin group (68.7%) (HR: 0.90, 95% CI: 0.85-0.95). No significant differences were observed in the rates of acute myocardial infarction (12.1% versus 12.2%; HR: 1.01, 95% CI: 0.88-1.16), gastrointestinal bleeding (6.9% versus 7.9%; HR: 0.89, 95% CI: 0.74-1.06), hematuria (8.0% versus 8.5%; HR: 0.96, 95% CI: 0.82-1.14), or intracranial hemorrhage (1.5% versus 2.0%; HR: 0.75, 95% CI: 0.52-1.09) between groups. DOACs demonstrated a lower risk of ischemic stroke and all-cause hospitalization rates compared with warfarin in patients with AF and oHCM, supporting the use of DOACs in this patient population.

Abstract Background The procedural synergy of PVI and LAAC in a single session is increasingly adopted in clinical workflows. However, the acute tissue response to PFA may influence LAAC device sizing and LAA complete seal. This preclinical study investigated healing dynamics, residual flow mechanisms, and structural device integrity using serial contrast CT and post-mortem micro-CT following combined PFA or RFA with WATCHMAN FLX Pro implantation. Methods Nine healthy canines underwent PVI using either PFA (n=6) or RFA (n=3), followed by LAAC in the same setting. Serial TEE and contrast-enhanced CT scans were acquired at baseline, post-procedure, and on days 7, 14, 28, and 45. All animals received DAPT for the duration of follow-up. Hypoattenuated Thickening (HAT) was evaluated to characterize healing and potential thrombus formation. Residual contrast patency was classified by source (e.g., uncovered trabeculations vs. trans-fabric flow). At terminal sacrifice, micro-CT imaging was performed with 35μm resolution and 1120×1120 pixel image size. CTvox software enabled 3D rendering of the devices, which were evaluated for grossly visible structural abnormalities, including fractures, disconnections, tangles, or other surface defects. Results All animals achieved successful LAAC with no acute complications. No device dislodgement was observed on imaging. At day 45, 5 animals (3 PFA, 2 RF) exhibited residual contrast patency. In 3 of these (1 PFA, 2 RF), the source was trans-fabric flow, suggesting incomplete endothelialization of the device fabric. The remaining 2 cases (both PFA) showed contrast patency due to small PDLs (&amp;lt;5mm) (Tables 1a and 1b). HAT was frequently observed early, with HAT noted in 5 animals by day 7 (4 PFA, 1 RFA) 2 of which were protruding – 1 in the PFA and one in the RFA group. Pedunculated HAT was not observed in any of the animals. All HATs evolved toward either a flat sessile phenotype or sub-fabric by day 45, with no evidence of protruding phenotype on final imaging. There were no major differences noted between the treatment groups. Micro-CT confirmed intact structural integrity in all devices despite extreme "deformation" to fit different LAAs 3D geometries, with no evidence of strut fractures, tangling, disconnection or device surface integrity breach (Figure 1). Conclusion In this preclinical model, concomitant PFA or RF ablation followed by WATCHMAN FLX Pro LAAC was procedurally feasible and safe, with no device dislodgment or thrombus formation. Residual contrast patency at day 45 occurred in 5 animals, with trans-fabric flow identified as the source in 3 and minor PDLs in 2 in the PFA group, pointing to a probable localized delay in endothelialization. Micro-CT imaging demonstrated structural device integrity despite deformation across various LAA morphologies.Figure 1 Tables 1a and 1b

Ventricular tachycardia (VT) is alife-threatening condition, and standard treatments are not suitable for many affected patients. Stereotactic arrhythmia radioablation (STAR) has emerged as apromising experimental last-resort treatment for patients with refractory VT, but it lacks clinical standardization. To address this issue, the STOPSTORM.eu consortium aims to collect data on patients treated with STAR via the development of amulticentric patient registry. The Ethics & Regulations Working Group (ERG) provides support addressing ethical and regulatory challenges. The ERG conducted asurvey to assess how prospective data on STAR are collected at the partner centres and to explore potential ethical concerns. Responses were analysed to evaluate clinical trial approval processes, adherence to STOPSTORM guidelines, and emerging ethical issues. Among the 28partners, there were 13interventional clinical trials-ongoing or concluded-across seven countries; centres without ongoing trials enrolled patients under compassionate use. Most trials were single arm, with few exceptions (arandomized trial and dose escalation studies). Most ethics committees approved STAR trials without major objections, but regulatory inconsistencies were observed, resulting in approval denial or delay. Ethical concerns included potential therapeutic misconception among patients, autonomy issues due to the vulnerability of VT patients, and inequities in access to STAR. The heterogeneity in trial designs, endpoints, and follow-up strategies among participating centres posed challenges for data standardization, but using aregistry to collect data from multiple local clinical trials offers an innovative approach to overcoming logistical and financial barriers in research on rare diseases. Multicentric non-pharmaceutical trials on STAR may present ethical, regulatory, and organizational challenges. The open registry model facilitates large-scale data collection and supports future protocol standardization. However, greater intercentre collaboration and regulatory harmonization are needed to optimize STAR's integration into clinical practice while upholding ethical standards in patient care and research.

Acknowledgements We thank all the local investigators and assistant personnel for their great effort. Furthermore, we thank all the POTTER-AF collaborators.

Dedicated radiofrequency (RF) needles and wires for transseptal puncture (TSP) achieve better outcomes vs. electrified open-ended needles and guidewires due to optimized electrode design and energy delivery. This study benchmarked TSP performance between the dedicated VersaCross wire system (VC; Boston Scientific) and an electrified guidewire with an alternative electrode configuration similar to commercially available devices. A 0.025″ guidewire (Cordis) was modified to mimic the 15cm 0.025″ distal uninsulated wire length of the HOTWIRE (Atraverse) device and electrified using a ValleyLab generator (EG; 30-50 W, 1s and 300ms). EG was extended 0-3.5mm from the dilator tip to mimic clinical use. RF puncture using VC and EG was performed on ex vivo porcine septa (n = 18) and in vivo swine heart (n = 3), to compare TSP performance, thermal damage and energy output measured using an oscilloscope. Ex vivo, VC had 100% TSP success with 1 attempt using 1s (constant) and 300ms (pulse) modes; EG demonstrated higher failure rates and less consistency at 30 W (78%) and 40 W (88%), requiring more RF applications, longer duration and energy output. EG crossings ex vivo and in vivo showed thermal damage on septa and device charring along the uninsulated distal end, unlike VC. Successful TSP with EG (1s, 30-50 W) in vivo demonstrated wire charring and thrombus along the uninsulated wire length within the dilator. Manual protrusion of a wire with a long uninsulated length can be difficult to control in a clinical setting, thus, introducing variability, excess energy, and risk of thermal injury and thrombus formation. A purpose-built electrode and dedicated generator optimize RF delivery for efficient and safe TSP.

Catheter ablation of scar-related interatrial septal atrial tachycardias (IAS-ATs) is challenging and can be refractory to conventional unipolar radiofrequency catheter ablation (RFCA). This multicenter study investigated the safety and efficacy of bipolar radiofrequency catheter ablation (Bi-RFCA) in patients with IAS-AT refractory to conventional unipolar RFCA. Consecutive patients with scar-related IAS-AT refractory to conventional unipolar RFA across three electrophysiological centers were included in the study. Bi-RFCA with power up to 40 W and duration up to 60s was performed with two ablation catheters across the IAS at sites identified with activation and entrainment mapping. Acute termination and noninducibility of the targeted IAS-AT was used as the intraprocedural ablation endpoint. Arrhythmia-free survival from any atrial arrhythmia (AT or atrial fibrillation) lasting > 30s was used as a follow-up outcome measure. A total of 17 patients (12 males, age 62 ± 13) were included in the study. Acute elimination of arrhythmia with Bi-RFCA was achieved in all patients. Mean procedure time was 173 ± 69min, mean bipolar RF time 209 ± 193s, and mean power 39 ± 3 W. During 11 ± 3months of follow-up, AT/AF recurrence was observed in 2 (12%) patients. No steam pops occurred during any of the Bi-RFCA applications and no other complications occurred during procedures or follow-up. Bi-RFCA is an effective and safe strategy to target scar-related IAS-AT refractory to standard unipolar RFCA.