Ultrasound guidance for femoral venous access in patients undergoing pulmonary vein isolation: A quasi-randomized study.

INTRODUCTION: Routine ultrasound (US) guidance for femoral venous access to decrease vascular complications of atrial fibrillation (AF) ablation procedures has been advocated. However, the benefit has not been unequivocally demonstrated by randomized-trial data. METHODS: Consecutive patients undergoing pulmonary vein isolation (PVI) on uninterrupted anticoagulant treatment were included. A quasi-random allocation to either US-guided or conventional puncture group was based on which of the two procedure rooms the patient was scheduled in, with only one of the rooms equipped with a US machine including a vascular transducer. The same four novice operators in rotation, with no relevant previous experience in US-guided vascular access performed venous punctures in both rooms. Major and minor vascular complications and the rate of prolonged hospitalization were compared. Major vascular complication was defined as groin hematoma, arteriovenous fistula, or pseudoaneurysm. Hematoma was considered as a major vascular complication if it met type 2 or higher Bleeding Academic Research Consortium criteria (requiring nonsurgical, medical intervention by a health care professional; leading to hospitalization or increased level of care, or prompting evacuation). RESULTS: Of the 457 patients 199 were allocated to the US-guided puncture group, while the conventional, palpation-based approach was performed in 258 cases. Compared with the conventional technique, US guidance reduced the rate of any vascular complication (11.63% vs. 2.01%, p < .0001), including both major (4.26% vs. 1.01%, p = .038) and minor (7.36% vs. 1.01%, p = .001) vascular complications. In addition, the rate of prolonged hospitalization was lower in the US-guided puncture group (5.04% vs. 1.01%, p = .032). CONCLUSION: The use of US for femoral vein puncture in patients undergoing PVI decreased the rate of both major and minor vascular complications. This quasi-randomized comparison strongly supports adapting routine use of US for AF ablation procedures.

A head-to-head comparison of laser vs. powered mechanical sheaths as first choice and second line extraction tools.

AIMS: During transvenous lead extraction (TLE) longer dwelling time often requires the use of powered sheaths. This study aimed to compare outcomes with the laser and powered mechanical tools. METHODS AND RESULTS: Single-centre data from consecutive patients undergoing TLE between 2012 and 2021 were retrospectively analysed. Efficacy and safety of the primary extraction tool were compared. Procedures requiring crossover between powered sheaths were also analysed. Moreover, we examined the efficacy of each level of the stepwise approach. Out of 166 patients, 142 (age 65.4 ± 13.7 years) underwent TLE requiring advanced techniques with 245 leads (dwelling time 9.4 ± 6.3 years). Laser sheaths were used in 64.9%, powered mechanical sheaths in 35.1% of the procedures as primary extraction tools. Procedural success rate was 85.5% with laser and 82.5% with mechanical sheaths (P = 0.552). Minor and major complications were observed in similar rate. Procedural mortality occurred only in the laser group in the case of three patients. Crossover was needed in 19.5% after laser and in 12.8% after mechanical extractions (P = 0.187). Among crossover procedures, only clinical success favoured the secondary mechanical arm (87.1 vs. 54.5%, aOR: 0.09, 95% CI: 0.01-0.79, P = 0.030). After step-by-step efficacy analysis, procedural success was 64.9% with the first-line extraction tool, 75.1% after crossover, 84.5% with bailout femoral snare, and 91.8% by non-emergency surgery. CONCLUSION: The efficacy and safety of laser and mechanical sheaths were similar, however in the subgroup of crossover procedures mechanical tools had better performance regarding clinical success. Device diversity seems to help improving outcomes, especially in the most complicated cases.

Risk of Cardiac Implantable Electronic Device Infection after Early versus Delayed Lead Repositioning.

(1) Background: Early reintervention increases the risk of infection of cardiac implantable electronic devices (CIEDs). Some operators therefore delay lead repositioning in the case of dislocation by weeks; however, there is no evidence to support this practice. The aim of our study was to evaluate the impact of the timing of reoperation on infection risk. (2) Methods: The data from consecutive patients undergoing lead repositioning in two European referral centers were retrospectively analyzed. The odds ratio (OR) of CIED infection in the first year was compared among patients undergoing early (≤1 week) vs. delayed (>1 week to 1 year) reoperation. (3) Results: Out of 249 patients requiring CIED reintervention, 85 patients (34%) underwent an early (median 2 days) and 164 (66%) underwent a delayed lead revision (median 53 days). A total of nine (3.6%) wound/device infections were identified. The risk of infection was numerically lower in the early (1.2%) vs. delayed (4.9%) intervention group yielding no statistically significant difference, even after adjustment for typical risk factors for CIED infection (adjusted OR = 0.264, 95% CI 0.032-2.179, p = 0.216). System explantation/extraction was necessary in seven cases, all being revised in the delayed group. (4) Conclusions: In this bicentric, international study, delayed lead repositioning did not reduce the risk of CIED infection.

Electrospun Iridium-Based Nanofiber Catalysts for Oxygen Evolution Reaction: Influence of Calcination on Activity-Stability Relation.

The enhanced utilization of noble metal catalysts through highly porous nanostructures is crucial to advancing the commercialization prospects of proton exchange membrane water electrolysis (PEMWE). In this study, hierarchically structured IrOx-based nanofiber catalyst materials for acidic water electrolysis are synthesized by electrospinning, a process known for its scalability and ease of operation. A calcination study at various temperatures from 400 to 800 °C is employed to find the best candidates for both electrocatalytic activity and stability. Morphology, structure, phase, and chemical composition are investigated using a scale-bridging approach by SEM, TEM, XRD, and XPS to shed light on the structure-function relationship of the thermally prepared nanofibers. Activity and stability are monitored by a scanning flow cell (SFC) coupled with an inductively coupled plasma mass spectrometer (ICP-MS). We evaluate the dissolution of all metals potentially incorporated into the final catalyst material throughout the synthesis pathway. Despite the opposite trend of performance and stability, the present study demonstrates that an optimum between these two aspects can be achieved at 600 °C, exhibiting values that are 1.4 and 2.4 times higher than those of the commercial reference material, respectively. The dissolution of metal contaminations such as Ni, Fe, and Cr remains minimal, exhibiting no correlation with the steps of the electrochemical protocol applied, thus exerting a negligible influence on the stability of the nanofibrous catalyst materials. This work demonstrates the scalability of electrospinning to produce nanofibers with enhanced catalyst utilization and their testing by SFC-ICP-MS. Moreover, it illustrates the influence of calcination temperature on the structure and chemical composition of the nanofibers, resulting in outstanding electrocatalytic performance and stability compared to commercial catalyst materials for PEMWE.

Reimplantation and long-term mortality after transvenous lead extraction in a high-risk, single-center cohort.

PURPOSE: The use of cardiac implantable electronic devices (CIEDs) has increased significantly over the last decades. With the development of transvenous lead extraction (TLE), procedural success rates also improved; however, data regarding long-term outcomes are still limited. The aim of our study was to analyze the outcomes after TLE, including reimplantation data, all-cause and cause-specific mortality. METHODS: Data from consecutive patients undergoing TLE in our institution between 2012 and 2020 were retrospectively analyzed. Periprocedural, 30-day, long-term, and cause-specific mortalities were calculated. We examined the original and the revised CIED indications and survival rate of patients with or without reimplantation. RESULTS: A total of 150 patients (age 66 ± 14 years) with 308 leads (dwelling time 7.8 ± 6.3 years) underwent TLE due to pocket infection (n = 105, 70%), endocarditis (n = 35, 23%), or non-infectious indications (n = 10, 7%). All-cause mortality data were available for all patients, detailed reimplantation data in 98 cases. Procedural death rate was 2% (n = 3), 30-day mortality rate 2.6% (n = 4). During the 3.5 ± 2.4 years of follow-up, 44 patients died. Arrhythmia, as the direct cause of death, was absent. Cardiovascular cause was responsible for mortality in 25%. There was no significant survival difference between groups with or without reimplantation (p = 0.136). CONCLUSIONS: Despite the high number of pocket and systemic infection and long dwelling times in our cohort, the short- and long-term mortality after TLE proved to be favorable. Moreover, survival without a new device was not worse compared to patients who underwent a reimplantation procedure. Our study underlines the importance of individual reassessment of the original CIED indication, to avoid unnecessary reimplantation.

Randomized trial of intracardiac echocardiography-guided slow pathway ablation.

PURPOSE: Radiofrequency (RF) catheter ablation of the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT) is highly effective; however, it may require prolonged fluoroscopy and RF time. We postulated that visualization of the SP region with intracardiac echocardiography (ICE) could decrease ablation time, minimize radiation exposure, and facilitate SP ablation compared to the standard, fluoroscopy-guided approach. METHODS: In our study, we randomized 91 patients undergoing electrophysiologic study and SP ablation for AVNRT into 2 groups: fluoroscopy-only (n = 48) or ICE-guided (n = 43) group. Crossover to ICE-guidance was allowed after 8 unsuccessful RF applications. RESULTS: Mapping plus ablation time (mean ± standard deviation: 18.8 ± 16.1 min vs 11.6 ± 15.0 min, p = 0.031), fluoroscopy time (median [interquartile range]: 4.9 [2.93-8.13] min vs. 1.8 [1.2-2.8] min, p < 0.001), and total ablation time (144 [104-196] s vs. 81 [60-159] s, p = 0.001) were significantly shorter in the ICE group. ICE-guidance was associated with reduced radiation exposure (13.2 [8.2-13.4] mGy vs. 3.7 [1.5-5.8] mGy, p < 0.001). The sum of delivered RF energy (3866 [2786-5656] Ws vs. 2283 [1694-4284] Ws, p = 0.002) and number of RF applications (8 [4.25-12.75] vs. 4 [2-7], p = 0.001) were also lower with ICE-guidance. Twelve (25%) patients crossed over to the ICE-guided group. All were treated successfully thereafter with similar number, time, and cumulative energy of RF applications compared to the ICE group. No recurrence occurred during the follow-up. CONCLUSIONS: ICE-guidance during SP ablation significantly reduces mapping and ablation time, radiation exposure, and RF delivery in comparison to fluoroscopy-only procedures. Moreover, early switching to ICE-guided ablation seems to be an optimal choice in challenging cases.