Catheter Ablation as First-Line Therapy in Persistent Atrial Fibrillation: Patient Characteristics and Clinical Outcomes.

BACKGROUND: In patients with persistent atrial fibrillation (PerAF), antiarrhythmic drugs (AADs) are considered a first-line rhythm-control strategy, whereas catheter ablation is a reasonable alternative. OBJECTIVES: This study sought to examine the prevalence, patient characteristics, and clinical outcomes of patients with PerAF who underwent catheter ablation as a first or second-line strategy. METHODS: This multicenter observational study included consecutive patients with PerAF who underwent first-time ablation between January 2020 and September 2021 in 9 medical centers in the United States. Patients were divided into those who underwent ablation as first-line therapy and those who had ablation as second-line therapy. Patient characteristics and clinical outcomes were compared between the groups. RESULTS: A total of 2,083 patients underwent first-time ablation for PerAF. Of these, 1,086 (52%) underwent ablation as a first-line rhythm-control treatment. Compared with patients treated with AADs as first-line therapy, these patients were predominantly male (72.6% vs 68.1%; P = 0.03), with a lower frequency of hypertension (64.0% vs 73.4%; P < 0.001) and heart failure (19.1% vs 30.5%; P < 0.001). During a mean follow-up of 325.9 ± 81.6 days, arrhythmia-free survival was similar between the groups (HR: 1.13; 95% CI: 0.92-1.41); however, patients in the second-line ablation strategy were more likely to continue receiving AAD therapy (41.5% vs 15.9%; P < 0.001). CONCLUSIONS: A first-line ablation strategy for PerAF is prevalent in the United States, particularly in men with fewer comorbidities. More data are needed to identify patients with PerAF who derive benefit from an early intervention strategy.

Dual-energy lattice-tip ablation system for persistent atrial fibrillation: a randomized trial.

Clinical outcomes of catheter ablation for atrial fibrillation (AF) are suboptimal due, in part, to challenges in achieving durable lesions. Although focal point-by-point ablation allows for the creation of any required lesion set, this strategy necessitates the generation of contiguous lesions without gaps. A large-tip catheter, capable of creating wide-footprint ablation lesions, may increase ablation effectiveness and efficiency. In a randomized, single-blind, non-inferiority trial, 420 patients with persistent AF underwent ablation using a large-tip catheter with dual pulsed field and radiofrequency energies versus ablation using a conventional radiofrequency ablation system. The primary composite effectiveness endpoint was evaluated through 1 year and included freedom from acute procedural failure and repeat ablation at any time, plus arrhythmia recurrence, drug initiation or escalation or cardioversion after a 3-month blanking period. The primary safety endpoint was freedom from a composite of serious procedure-related or device-related adverse events. The primary effectiveness endpoint was observed for 73.8% and 65.8% of patients in the investigational and control arms, respectively (P < 0.0001 for non-inferiority). Major procedural or device-related complications occurred in three patients in the investigational arm and in two patients in the control arm (P < 0.0001 for non-inferiority). In a secondary analysis, procedural times were shorter in the investigational arm as compared to the control arm (P < 0.0001). These results demonstrate non-inferior safety and effectiveness of the dual-energy catheter for the treatment of persistent AF. Future large-scale studies are needed to gather real-world evidence on the impact of the focal dual-energy lattice catheter on the broader population of patients with AF. ClinicalTrials.gov identifier: NCT05120193 .

Safety and Effectiveness of a Next-Generation Contact Force Catheter: Results of the TactiSense Trial.

OBJECTIVES: The objective of this clinical trial was to evaluate the safety and effectiveness of the TactiCath Contact Force Ablation Catheter, Sensor Enabled (TactiCath SE) (Abbott, Abbott Park, Illinois) for the treatment of drug-refractory, symptomatic paroxysmal atrial fibrillation (PAF). BACKGROUND: Catheter ablation of atrial fibrillation (AF) is an established therapy for the treatment of PAF. Ablation technology is evolving with the primary goals of improving efficacy and safety of the procedure. METHODS: This was a multicenter single-arm trial evaluating a novel ablation catheter for the treatment of PAF. A total of 156 subjects were enrolled at 19 sites in the United States, Europe, and Australia. The primary safety endpoint was the rate of device- or procedure-related serious adverse events occurring within 7 days. The primary effectiveness endpoint was acute success defined as pulmonary vein isolation at 30 min after ablation. Two descriptive endpoints were prospectively captured: 1) 1-year freedom from recurrence of symptomatic AF, atrial flutter (AFL), and atrial tachycardia (AT) lasting ≥30 s without a new or increased dose of Class I/III antiarrhythmic drugs; and 2) 1-year drug-free success defined by the absence of any recurrent AF/AFL/AT lasting ≥30 s without using Class I/III antiarrhythmic drugs. RESULTS: Primary safety events occurred in 4.7% of patients (95% confidence interval [CI]: 2.23% to 8.64%), and the procedure was acutely successful in 98.0% of patients (95% CI: 94.95% to 99.46%). According to Kaplan-Meier estimates at 1 year, 82.2% (95% CI: 74.7% to 87.6%) were free from symptomatic recurrence, and 1-year drug-free success was 68.2% (95% CI: 59.9% to 75.1%). CONCLUSIONS: The TactiCath™ Contact Force Ablation Catheter, Sensor Enabled™ is safe and effective for the treatment of paroxysmal AF.

High-resolution, real-time, and nonfluoroscopic 3-dimensional cardiac imaging and catheter navigation in humans using a novel dielectric-based system.

BACKGROUND: Catheter navigation and 3-dimensional (3D) cardiac mapping are essential components of minimally invasive electrophysiological procedures. OBJECTIVE: The purpose of this study was to develop a novel 3D mapping system (KODEX - EPD, EPD Solutions, Best, The Netherlands) that measures changing electric field gradients induced on intracardiac electrodes to enable catheter localization and real-time 3D cardiac mapping. METHODS: We first validated the accuracy of the system's measurement and localization capabilities by comparing known and KODEX - EPD-measured distances and locations at 12 anatomical landmarks in both the atria and ventricles of 4 swine. Next, in vivo images of 3D porcine cardiac anatomy generated by KODEX - EPD and widely used CARTO 3 system (Biosense Webster, Inc., Diamond Bar, CA) were compared with gold standard computed tomography images acquired from the same animals. Finally, 3D maps of atrial anatomy were created for 22 patients with paroxysmal atrial fibrillation (Dielectric Unravelling of Radiofrequency ABLation Effectiveness trial). RESULTS: First, the mean error between known and measured distances was 1.08 ± 0.11 mm (P < .01) and the overall standard deviation between known and measured locations in 12 areas of the porcine heart was 0.35 mm (P < .01). Second, an expert comparison of 3D image quality revealed that KODEX - EPD is noninferior to CARTO 3. Third, the system enabled 3D imaging of atrial anatomy in humans, provided real-time images of atrioventricular valves, and detected important anatomical variations in a subset of patients. CONCLUSION: The KODEX - EPD system is a novel 3D mapping system that accurately detects catheter location and can generate high-resolution images without the need for preacquired imaging, specialty catheters, or a point-by-point mapping procedure.

Decal-Lenses: Interactive Lenses on Surfaces for Multivariate Visualization.

We present decal-lenses, a new interaction technique that extends the concept of magic lenses to augment and manage multivariate visualizations on arbitrary surfaces. Our object-space lenses follow the surface geometry and allow the user to change the point of view during data exploration while maintaining a spatial reference to positions where one or more lenses were placed. Each lens delimits specific regions of the surface where one or more attributes can be selected or combined. Similar to 2D lenses, the user interacts with our lenses in real-time, switching between different attributes within the lens context. The user can also visualize the surface data representations from the point of view of each lens by using local cameras. To place lenses on surfaces of intricate geometry, such as the human brain, we introduce the concept of support surfaces for designing interaction techniques. Support surfaces provide a way to place and interact with the lenses while avoiding holes and occluded regions during data exploration. We further extend decal-lenses to arbitrary regions using brushing and lassoing operations. We discuss the applicability of our technique and present several examples where our lenses can be useful to create a customized exploration of multivariate data on surfaces.

A SURVEY OF DISPOSITION OF PHYSICIANS TOWARDS PHYSICAL ACTIVITY PROMOTION AT TWO TERTIARY HOSPITALS IN NORTH-EASTERN NIGERIA.

BACKGROUND: A general presumption is that any advice from physicians would likely be taken seriously by patients, and patients are more likely to see their doctors in the event of any health complaints than any other health professionals. The perceptions and practice of Nigerian physicians on their role in physical activity promotion are not well known. This study aimed to determine the knowledge of physical activity message, confidence, role perceptions, barriers and feasibility of physical activity promotion among physicians in two tertiary health institutions in North-Eastern Nigeria. METHOD: A total of 153 (84.5% response) physicians at the University of Maiduguri Teaching Hospital and Federal Medical Center Yola completed a previously developed questionnaire that elicited information on their knowledge, barrier, feasibility, role and confidence in physical activity promotion. RESULTS: Physicians in this study reported fairly good knowledge (mean score=14.7±2.2/20), minimal or little barrier to physical activity promotion (mean score=24.4±3.5/30), perceived physical activity promotion as their role (mean score=12.9±1.6/15), were confident in their ability to discuss and recommend exercises for physical activity promotion (mean score=7.9±1.3/ 10) and believed promoting physical activity was feasible for them (mean score=15.0±2.5/20). The physicians had good disposition to physical activity promotion (Mean score=78.5±6.7/100), but male physicians showed better disposition than their female counterparts. CONCLUSION: Overall these cohorts of physicians are somewhat knowledgeable on physical activity promotion and are positively disposed to promoting physical activity among their patients. These findings can be leveraged upon to optimize outcome of campaigns or interventions to change physical activity behaviour in Nigerian populace.

Toward high-quality gradient estimation on regular lattices.

In this paper, we present two methods for accurate gradient estimation from scalar field data sampled on regular lattices. The first method is based on the multidimensional Taylor series expansion of the convolution sum and allows us to specify design criteria such as compactness and approximation power. The second method is based on a Hilbert space framework and provides a minimum error solution in the form of an orthogonal projection operating between two approximation spaces. Both methods lead to discrete filters, which can be combined with continuous reconstruction kernels to yield highly accurate estimators as compared to the current state of the art. We demonstrate the advantages of our methods in the context of volume rendering of data sampled on Cartesian and Body-Centered Cubic lattices. Our results show significant qualitative and quantitative improvements for both synthetic and real data, while incurring a moderate preprocessing and storage overhead.

Gradient estimation revitalized.

We investigate the use of a Fourier-domain derivative error kernel to quantify the error incurred while estimating the gradient of a function from scalar point samples on a regular lattice. We use the error kernel to show that gradient reconstruction quality is significantly enhanced merely by shifting the reconstruction kernel to the centers of the principal lattice directions. Additionally, we exploit the algebraic similarities between the scalar and derivative error kernels to design asymptotically optimal gradient estimation filters that can be factored into an infinite impulse response interpolation prefilter and a finite impulse response directional derivative filter. This leads to a significant performance gain both in terms of accuracy and computational efficiency. The interpolation prefilter provides an accurate scalar approximation and can be re-used to cheaply compute directional derivatives on-the-fly without the need to store gradients. We demonstrate the impact of our filters in the context of volume rendering of scalar data sampled on the Cartesian and Body-Centered Cubic lattices. Our results rival those obtained from other competitive gradient estimation methods while incurring no additional computational or storage overhead.

The Lattice-Boltzmann method on optimal sampling lattices.

In this paper, we extend the single relaxation time Lattice-Boltzmann Method (LBM) to the 3D body-centered cubic (BCC) lattice. We show that the D3bQ15 lattice defined by a 15 neighborhood connectivity of the BCC lattice is not only capable of more accurately discretizing the velocity space of the continuous Boltzmann equation as compared to the D3Q15 Cartesian lattice, it also achieves a comparable spatial discretization with 30 percent less samples. We validate the accuracy of our proposed lattice by investigating its performance on the 3D lid-driven cavity flow problem and show that the D3bQ15 lattice offers significant cost savings while maintaining a comparable accuracy. We demonstrate the efficiency of our method and the impact on graphics and visualization techniques via the application of line-integral convolution on 2D slices as well as the extraction of streamlines of the 3D flow. We further study the benefits of our proposed lattice by applying it to the problem of simulating smoke and show that the D3bQ15 lattice yields more detail and turbulence at a reduced computational cost.

Serum levels of interferon-gamma, tumour necrosis factor-alpha, soluble interleukin-6R and soluble cell activation markers for monitoring response to treatment of leprosy reactions.

Identifying pathogen and host-related laboratory parameters are essential for the early diagnosis of leprosy reactions. The present study aimed to clarify the validity of measuring the profiles of serum cytokines [interleukin (IL)-4, IL-6, IL-10, interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha], the soluble IL-6 receptor (sIL-6R), soluble T cell (sCD27) and macrophage (neopterin) activation markers and Mycobacterium leprae-specific anti-PGL-I IgM antibodies in relation to the leprosy spectrum and reactions. Serum samples from 131 Indonesian leprosy patients (82 non-reactional leprosy patients and 49 reactional) and 112 healthy controls (HC) from the same endemic region were investigated. Forty-four (89.8%) of the reactional patients had erythema nodosum leprosum (ENL) while only five (10.2%) had reversal reaction (RR). Follow-up serum samples after corticosteroid treatment were also obtained from 17 of the patients with ENL and one with RR. A wide variability in cytokine levels was observed in the patient groups. However, IFN-gamma and sIL-6R were elevated significantly in ENL compared to non-ENL patients. Levels of IFN-gamma, TNF-alpha and sIL-6R declined significantly upon corticosteroid treatment of ENL. Thus, although the present study suggests limited applicability of serial measurement of IFN-gamma, TNF-alpha and sIL-6R in monitoring treatment efficacy of ENL, reactions it recommends a search for a wider panel of more disease-specific markers in future studies.