Feasibility of double-blinded, placebo-controlled interventional study for assessing catheter ablation efficacy in persistent atrial fibrillation: Insights from the ORBITA AF feasibility study.

BACKGROUND: To date, there are no randomized, double-blinded clinical trials comparing catheter ablation to DC cardioversion (DCCV) with medical therapy in patients with persistent atrial fibrillation (PersAF). Conducting a large-scale trial to address this question presents considerable challenges, including recruitment, blinding, and implementation. We conducted a pilot study to evaluate the feasibility of conducting a definitive placebo-controlled trial. METHODS: This prospective trial was carried out at Barts Heart Centre, United Kingdom, employing a randomized, double-blinded, placebo-controlled design. Twenty patients with PersAF (duration <2 years) were recruited, representing 10% of the proposed larger trial as determined by a power calculation. The patients were randomized in a 1:1 ratio to receive either PVI ± DCCV (PVI group) or DCCV + Placebo (DCCV group). The primary endpoint of this feasibility study was to evaluate patient blinding. Patients remained unaware of their treatment allocation until end of study. RESULTS: During the study, 35% of patients experienced recurrence of PersAF prior to completion of 12 months follow-up. Blinding was successfully maintained amongst both patients and medical staff. The DCCV group had a trend to higher recurrence and repeat procedure rate compared to the PVI group (recurrence of PersAF 60% vs 30%; p = .07 and repeat procedure 70% vs 40%; p = .4). The quality of life experienced by individuals in the PVI group showed improvement, as evidenced by enhanced scores on the AF specific questionnaire (AF PROMS) (3 [±4] vs 21 [±8]) and SF-12 mental-component raw score (51.4 [±7] vs 43.24 [±15]) in patients who maintained sinus rhythm at 12 months. CONCLUSION: This feasibility study establishes the potential for conducting a blinded, placebo-controlled trial to evaluate the efficacy of PVI versus DCCV in patients with PersAF.

Catheter ablation of atrial fibrillation with a multi-electrode radiofrequency balloon; first and early two centre experience in Europe.

INTRODUCTION: The Heliostar™ ablation system is a novel RF balloon ablation technology with an integrated three-dimensional mapping system. Here, we describe our early experience and procedural outcomes using this technology for atrial fibrillation catheter ablation. METHODS: We sought to comprehensively assess the first 60 consecutive patients undergoing pulmonary vein isolation using the novel HELISOTAR™ RF balloon technology including procedural outcomes. A comparison of the workflow between two different anaesthetic modalities (conscious sedation [CS] vs. general anaesthesia [GA]) was made. Procedural data were collected prospectively from two high-volume centers (Barts Heart Centre, UK and University Hospital of Zurich, Zurich). A standardized approach for catheter ablation was employed. RESULTS: A total of 35 patients had the procedure under CS and the remaining under GA. Mean procedural and fluoroscopy times were 84 ± 33 min and 1.1 min. The median duration of RF energy application was 7 (5-9.8) mins per patient. All veins were successfully isolated, and the median isolation time was 10 (7-15) seconds. Our cohort's rate of procedural complications was low, with no mortality within 30 days postprocedure. CONCLUSION: Our early experience shows that catheter ablation using the Heliostar™ technology can be performed efficiently and safely; however, long-term data is yet to be established. Low fluoroscopy requirements, short learning curves and use of this technology with CS is possible, including the use of an oesophageal temperature probe.

The role of CT in detecting AF substrate.

Despite technological advancements and evolving ablation strategies, atrial fibrillation catheter ablation outcome remains suboptimal for a cohort of patients. Imaging-based biomarkers have the potential to play a pivotal role in the overall assessment and prognostic stratification of AF patients, allowing for tailored treatments and individualized care. Alongside consolidated evaluation parameters, novel imaging biomarkers that can detect and stage the remodelling process and correlate it to electrophysiological phenomena are emerging. This review aims to provide a better understanding of the different types of atrial substrate, and how Computed Tomography can be used as a pre-ablation risk stratification tool by assessing the various novel imaging biomarkers, providing a valuable insight into the mechanisms that sustain AF and potentially allowing for a patient-specific ablation strategy.

Impact of obesity on atrial fibrillation ablation.

Obesity is a major risk factor for atrial fibrillation. It also influences the natural history of the disease, leading to more persistent forms and poorer ablation outcomes. This article reviews atrial fibrillation ablation in the obese population, focusing on outcomes, complications and periprocedural management. Through an analysis of the possible pathophysiological mechanism linking obesity and atrial fibrillation, we identify potential strategies to improve post-ablation outcomes in this challenging population.

Anatomical variations of the posterior circulation: case reports and a review of literature.

INTRODUCTION: The intracranial vascular anatomical variations, although rare, represent a interesting field of research, since many anomalous variants are possible and in most cases they remain asymptomatic. The capability of the cerebral circulation to adapt to several flow changes is confirmed by the fact that in several cases these anatomical variation compensate for an eventual unsuccessful development of the normal circulation, expecially in the posterior section of cerebral circulation. MATERIALS AND METHODS: A comprehensive review of PubMed literature was performed and three clinical cases have been analyzed. RESULTS: Several angiographic and MR-angiography reports have been evaluated, regarding general and specific anatomical variants of the posterior circulation. DISCUSSION: Although rare, the anatomical variations of the posterior intracranial circulation represent an interesting field of investigation in order to achieve a better comprehension of the embryological development of the circulatory system.