Purpose of review The cryoballoon catheter has been an option for the treatment of atrial fibrillation for over a decade. The most widely used device is the Medtronic Arctic Advance cryoballoon catheter. Recently, Boston Scientific has released the POLARx cryoballoon catheter. Here we review the major changes in the catheter system's design and its implications for procedural practice. Recent findings The POLARx cryoballoon catheter has been approved for use in Europe. Some studies have been published detailing the first clinical experiences in vivo with this newest technology. Summary The changes to the POLARx cryoballoon catheter, particularly its ability to maintain balloon size and pressure, will improve occlusion and theoretically improve procedural outcomes.

Background With advancements in technology and ablation techniques, catheter ablation for the treatment of atrial fibrillation (AF) has become safer with time. In the past, standard-of-care recommended overnight stay for outpatient procedures. As safety has improved and procedure times have shortened, some centers have allowed for same-day discharge. We report the results of a multi-center, randomized clinical trial investigating the safety of same-day discharge post-cryoballoon ablation. Methods Patients with paroxysmal atrial fibrillation underwent pulmonary vein isolation (PVI) with the Medtronic Arctic Advance cryoballoon at 3 US centers. Six hours after the procedure, patients were randomized to either stay overnight or be discharged same day. Results A total of 49 patients were enrolled. Two patients were withdrawn prior to randomization. One patient chose to withdraw after randomization. Of the 22 patients randomized to same-day discharge and the 23 patients randomized the overnight stay, no significant adverse outcomes were reported in either group. Occurrence of adverse events did not differ significantly between the two groups. Procedure time and fluoroscopy time did not significantly differ between groups. Conclusions This is the first randomized trial examining the safety of same-day discharge post-cryoballoon ablation. Based on our results, same-day discharge following cryoballoon ablation for paroxysmal AF is a safe option following uncomplicated ablation for PVI. Operators should use their discretion in selecting patients for same-day discharge.

Introduction: Cryoballoon ablation for atrial fibrillation (AF) has been widely adopted clinically. However, dislodgement from the pulmonary vein (PV) ostium following freeze initiation commonly occurs due to a sudden rise in balloon pressure, known as the “pop-out” phenomenon. This can often only be partially detected using continuous color Doppler or repeat angiography after the initiation of freeze. We aim to access the incidence of this phenomenon using the dielectric imaging system in comparison to intracardiac echocardiography (ICE). Methods: Ten patients underwent de novo cryoballoon ablation for paroxysmal or persistent AF with the use of the KODEX-EPD dielectric imaging system (Philips, Amsterdam, Netherlands). A baseline assessment and injection were performed pre-ablation followed by analysis of occulsion via the KODEX Occlusion Viewer. Simultaneous assessment was performed by the operator utilizing ICE. Repeat assessment with injection was performed after ablation start to assess whether the cryoballoon remained occluded on ICE and by KODEX’s occlusion assessment. Results: There was a high correlation between KODEX and ICE for assessment of balloon occlusion prior to ablation (91.7±23.6%). KODEX demonstrated an overall sensitivity (88.6%), specificity (75.0%), positive predictive value (76.5%), and negative predictive value (87.8%) of the occlusion tool validated by ICE. Both imaging modalities detected a leak after initial full occlusion, an incidence of 24.3% on Kodex and 23.8% on ICE. Conclusions: Balloon contact with the PV is vital for an effective, transmural lesion. The dielectric imaging system and ICE confirmed high incidence of this “pop-out” phenomenon, which can lead to incomplete PV isolation. The KODEX-EPD occlusion tool is highly sensitive and specific to assist in the identification of this phenomenon and may improve the outcome for cryoballoon procedures. In the future a more compliant cryoballoon design, without a shift in balloon pressure during ablation, may avoid this phenomenon.

Purpose of reviewDespite technological advancements in catheter ablation, patients with atrial fibrillation often require multiple ablations, with diminishing returns depending on duration and persistence. Although early ablation is vital, modification of atrial fibrillation disease can be achieved with modification of existing risk factors. Obesity is an important modifiable risk factor, but there does not appear to be a consensus on the best method or goal for weight reduction.Recent findingsThe relationship between atrial fibrillation and obesity has been acknowledged. This review examines the clinical evidence demonstrating the benefit of weight reduction in the management of atrial fibrillation. In particular, this review compares the different approaches of recent studies.SummaryOn the basis of the literature, the authors recommend a structured weight loss programme with dietary and behavioural modifications individualized to each patient and including the implementation of physical activity. Consideration of bariatric surgery is appropriate in certain patients with obesity.