A Randomized Trial of Electrographic Flow-Guided Redo Ablation for Nonparoxysmal Atrial Fibrillation (FLOW-AF).

BACKGROUND: Electrographic flow (EGF) mapping enables full spatiotemporal reconstruction of organized wavefront propagation to identify extrapulmonary vein sources of atrial fibrillation (AF). OBJECTIVES: FLOW-AF (A Randomized Controlled Study to Evaluate the Reliability of the Ablacon Electrographic FLOW [EGF] Algorithm Technology [Ablamap Software] to Identify AF Sources and Guide Ablation Therapy in Patients With Persistent Atrial Fibrillation) was multicenter, randomized controlled study of EGF mapping to: 1) stratify a nonparoxysmal AF population undergoing redo ablation; 2) guide ablation of these extrapulmonary vein AF sources; and 3) improve AF recurrence outcomes. METHODS: FLOW-AF enrolled persistent atrial fibrillation (PerAF)/long-standing PerAF patients undergoing redo ablation at 4 centers. One-minute EGF maps were recorded from standardized biatrial basket positions. Patients with source activity ≥26.5% were randomized 1:1 to PVI + EGF-guided ablation vs PVI only; patients without sources ≥26.5% threshold were not randomized. Follow-up and electrocardiographic monitoring occurred at 3, 6, and 12 months. RESULTS: We enrolled 85 patients (age 65.6 ± 9.3 years, 37% female, 24% long-standing PerAF). Thirty-four (40%) patients had no sources greater than threshold; at least 1 source greater than threshold was present in 46 (60%) (EGF-guided ablation, n = 22; control group, n = 26). Patients with sources were older (68.2 vs 62.6 years; P = 0.005) with higher CHA2DS2-VASc scores (2.8 vs 1.9; P = 0.001). The freedom from safety events was 97.2%, and 95% of EGF-identified sources were successfully ablated. In randomized patients, AF-free survival at 12 months was 68% for EGF-guided ablation vs 17% for the control group (P = 0.042); freedom from AF/atrial tachycardia/atrial flutter at 12 months was 51% vs 14% (P = 0.103), respectively. CONCLUSIONS: In nonparoxysmal AF patients undergoing redo ablation, EGF mapping identified AF sources in 60% of patients, and could be successfully ablated in 95%. Compared with PVI alone, PVI + source ablation improved AF-free survival by 51% on an absolute basis. (FLOW-AF: A Study to Evaluate the Ablacon Electrographic FLOW EGF Technology [A Randomized Controlled Study to Evaluate the Reliability of the Ablacon Electrographic FLOW (EGF) Algorithm Technology (Ablamap Software) to Identify AF Sources and Guide Ablation Therapy in Patients With Persistent Atrial Fibrillation]; NCT04473963).

Device infection in patients undergoing pacemaker or defibrillator surgery: risk stratification using the PADIT score.

BACKGROUND: The use of an antibacterial envelope is cost-effective for patients at high risk of developing cardiac implantable electronic device (CIED) infection. The identification of these high-risk patients may be facilitated using a clinical risk score. The aim of the current study is to evaluate the PADIT score for identifying high-risk patients in patients undergoing a CIED procedure in a tertiary academic center. METHODS: This was a retrospective single-center study of consecutive patients undergoing a CIED procedure between January 2016 and November 2021. Patients who received an antibacterial envelope were excluded from this study. The primary endpoint was hospitalization for a CIED infection in the first year after the procedure. RESULTS: A total of 2333 CIED procedures were performed in the study period (mean age 61.6 ± 16.3 years, male sex 64.5%, previous CIED infection 1.7%, immunocompromised 5.4%). The median PADIT score was 4 (interquartile range, 2-6). CIED infection occurred in 10 patients (0.43%). The PADIT score had good discrimination in predicting major CIED infection (C-statistic 0.70; 95% confidence interval [CI] 0.54 to 0.86, P = 0.03). Using an optimal PADIT score cut-off value of 7, the risk of CIED infection was higher in the patients with a PADIT score of ≥ 7 in comparison to those with a lower PADIT score (1.23% vs. 0.26%, P = 0.02; odds ratio 4.8, 95% CI 1.4 to 16.6, P = 0.01). CONCLUSIONS: The PADIT score is a clinically useful score for identifying patients at high risk of developing CIED infection. The use of an antibacterial envelope in these high-risk patients may be cost-effective.

Robotic magnetic navigation-guided catheter ablation establishes highly effective pulmonary vein isolation in patients with paroxysmal atrial fibrillation when compared to conventional ablation techniques.

INTRODUCTION: Pulmonary vein isolation (PVI) is a pivotal part of ablative therapy for atrial fibrillation (AF). Currently, there are multiple techniques available to realize PVI, including: manual-guided cryoballoon (MAN-CB), manual-guided radiofrequency (MAN-RF), and robotic magnetic navigation-guided radiofrequency ablation (RMN-RF). There is a lack of large prospective trials comparing contemporary RMN-RF with the more conventional ablation techniques. This study prospectively compared three catheter ablation techniques as treatment of paroxysmal AF. METHODS: This multicenter, prospective study included patients with paroxysmal AF who underwent their first ablation procedure. Procedural parameters (including procedural efficiency), complication rates, and freedom of AF during 12-month follow-up, were compared between three study groups which were defined by the utilized ablation technique. RESULTS: A total of 221 patients were included in this study. Total procedure time was significantly shorter in MAN-CB (78 ± 21 min) compared to MAN-RF (115 ± 41 min; p < .001) and compared to RMN-RF (129 ± 32 min; p < .001), whereas it was comparable between the two radiofrequency (RF) groups (p = .062). A 3% complication rate was observed, which was comparable between all groups. At 12-month follow-up, AF recurrence was observed in 40 patients (19%) and was significantly lower in the robotic group (MAN-CB 19 [24%], MAN-RF 16 [23%], RMN-RF 5 [8%] AF recurrences, p = .045) (multivariate hazard ratio of RMN-RF on AF recurrence 0.32, 95% confidence interval: 0.12-0.87, p = .026). CONCLUSION: RMN-guided PVI results in high freedom of AF in patients with paroxysmal AF, when compared to cryoablation and manual RF ablation. Cryoablation remains the most time-efficient ablation technique, whereas RMN nowadays has comparable efficiency with manual RF ablation.

Identification of the Neoaspergillic Acid Biosynthesis Gene Cluster by Establishing an In Vitro CRISPR-Ribonucleoprotein Genetic System in Aspergillus melleus.

Filamentous fungi are an essential source of bioactive mycotoxins. Recent efforts have focused on developing antifungal agents that are effective against invasive yeasts, such as Candida spp. By screening fungal strains isolated from regions surrounding the Chernobyl nuclear power plant disaster for antifungal activity against Candida albicans, we found that Aspergillus melleus IMV 01140 produced compounds that inhibited the growth of the yeast. The active compound produced by A. melleus was isolated and found to be neoaspergillic acid, a compound that is closely related to aspergillic acid. While aspergillic acid and its derivatives have been characterized and were found to have antibacterial and antifungal properties, neoaspergillic acid has been much less studied. Even though neoaspergillic acid and related compounds were found to have antibacterial and antitumoral effects, further investigation into this group of compounds is limited by challenges associated with large-scale production, isolation, and purification. The production of neoaspergillic acid has been shown to require co-cultivation methods or special growth conditions. In this work, neoaspergillic acid and related compounds were found to be produced by A. melleus under laboratory growth conditions. The biosynthetic gene cluster of neoaspergillic acid was predicted using the aspergillic acid gene cluster as a model. The biosynthetic pathway for neoaspergillic acid was then confirmed by establishing an in vitro CRISPR-ribonucleoprotein system to individually delete genes within the cluster. A negative transcriptional factor, mcrA, was also eliminated to further improve the production of neoaspergillic acid and the related compounds for future studies.

The performance of dipole charge density mapping integrated with robotic magnetic navigation in the treatment of atrial tachycardias.

BACKGROUND: Catheter ablation (CA) has become a well-established first-line therapy for a broad spectrum of arrhythmias, including atrial tachycardias (ATs). In this study we aimed to assess the performance of the integrated novel high-resolution new generation noncontact mapping system (AcQMap) with robotic magnetic navigation (RMN) system in CA procedures for patients with ATs including comparing patient subgroups based on the utilized mapping modality, arrhythmia mechanism, localization and type of procedure. METHODS: All patients undergoing CA for AT using the AcQMap-RMN system were included. Procedural safety and efficacy were characterized by intra- and post-procedural complications. Acute procedural success and the long-term outcome were assessed in the overall group and in the subgroups. RESULTS: A total number of 70 patients were referred for CA with atrial arrhythmias including 67 AT/AFL (mean age 57.1 ± 14.4 years), and 3 additional patients with inappropriate sinus tachycardia. Thirty-eight patients had de novo AT, 24 had post-PVI AT including 2 patients with perinodal AT, and 5 had post-MAZE AT. Two patients (2.9%) suffered post-procedural complications including 1 patient with groin hematoma and 1 patient with a transient ischemic attack. Acute success was achieved in 63/67 (94.0%) procedures. Thirteen patients (19.4%) had documented recurrence at the end of the 12-months follow-up period. The performance of AcQMap was equally good in focal vs. reentry mechanisms (p = 0.61, acute success), in the left and right atrium (p = 0.21). CONCLUSIONS: AcQMap-RMN integration might improve success rates in CA of ATs with low number of complications.

Single-beat global atrial mapping facilitates the treatment of short-lived atrial tachycardias and infrequent premature atrial contractions.

BACKGROUND: Short runs of atrial tachycardias (ATs) and infrequent premature atrial contractions (PACs) are difficult to map and ablate using sequential electrophysiology mapping techniques. The AcQMap mapping system allows for highly accurate mapping of a single atrial activation. OBJECTIVES: We aimed to test the value of a novel dipole charge density-based high-resolution mapping technique (AcQMap) in the treatment of brief episodes of ATs and PACs. METHODS: Data of all patients undergoing catheter ablation (CA) using the AcQMap mapping system were reviewed. RESULTS: Thirty-one out of 219 patients (male n = 8; female n = 23) had short runs of ATs (n = 23) and PACs (n = 8). The mean procedural time was 155.3 ± 46.6 min, with a mean radiation dose of 92.0 (IQR 37.0-121.0) mGy. Total radiofrequency application duration 504.0 (271.0-906.0) s. Left atrial localization of ATs and PACs was identified in 45.1% of the cases, right atrium localization in 45.1%, and septal origins in 9.8% of the cases. Acute success was achieved in 30/31 (96.8%), and recurrence during the follow-up developed in six patients (19.4%), including four patients with PACs and two patients with short-lived ATs. One patient presented procedure-related groin hematoma as minor complication. CONCLUSION: Brief episodes of highly symptomatic ATs and infrequent PACs can be mapped using charge density mapping and successfully ablated with high acute and long-term success rates.

Use of a novel integrated dilator-needle system in cryoballoon procedures: a zero-exchange approach.

BACKGROUND: Recently, a novel integrated dilator-needle system (AcQCross Qx, Acutus Medical) was introduced to reduce the number of exchanges for a transseptal access. This system can be used in combination with large bore sheaths. In this pilot study, we evaluated the safety and efficacy of a zero-exchange approach with the AcQCross system in cryoballoon procedures. METHODS: In this retrospective single-center study, we included 40 patients (AcQCross: n = 20; control group: n = 20) who underwent a cryoballoon procedure for the treatment of atrial fibrillation. In the AcQCross and control group, patients underwent ablation with POLARx (Boston Scientific) and Arctic Front Advance Pro (AFA-Pro, Medtronic) in equal numbers (n = 10). In the AcQCross group, the AcQGuide Max sheath (Acutus Medical) was used in all POLARx cases. RESULTS: The baseline characteristics of the study population were comparable between groups. In the AcQCross group, there was a reduction in procedure time (49.7 ± 9.0 min vs. 59.6 ± 8.1 min, P < 0.001) and time from puncture until balloon delivery (15.5 ± 6.8 min vs. 21.5 ± 7.4 min, P = 0.01) in comparison with the control group. The balloon in body time, fluoroscopy time, number of cryoapplications, and biophysical parameters were similar between groups. There was one temporary phrenic nerve injury in the AcQCross group. Importantly, no signs of air embolism were noted with the AcQGuide Max sheath. CONCLUSIONS: The use of the novel AcQCross system improves procedural efficacy in cryoballoon procedures by reducing the number of exchanges.

The First Evaluation of Remote Magnetic Navigation-Guided Pediatric Ventricular Arrhythmia Ablation.

Catheter ablation (CA) is an important treatment option for ventricular arrhythmias (VA) in pediatric cardiology. Currently, various CA techniques are available, including remote magnetic navigation (RMN)-guided radiofrequency (RF) ablation. However, no studies evaluate RMN-guided ablative therapy outcomes in children with VA yet. This study aimed to compare procedural and long-term outcomes between RMN-guided and manual (MAN)-guided VA ablation in children. This single-center, retrospective study included all CA procedures for VA performed in children with or without structural heart disease from 2008 until 2020. Two study groups were defined by CA technique: RMN or MAN. Primary outcome was recurrence of VA. Baseline clinical, procedural and safety data were also evaluated. This study included 22 patients, who underwent 30 procedures, with a median age of 15 (IQR 14-17; range 1-17) years and a mean weight of 57 ± 20 kg. In total, 14 procedures were performed using RMN and 16 using MAN (22 first and 8 redo procedures). Regarding first procedures, recurrence rates were significantly lower in RMN compared to MAN (20% versus 67%, P = 0.029), at a mean follow-up of 5.2 ± 3.0 years. Moreover, fluoroscopy dosages were significantly lower in RMN compared to MAN [20 (IQR 14-54) versus 48 (IQR 38-62) mGy, P = 0.043]. In total, 20 patients (91%) were free of VA following their final ablation procedure. This is the first study to investigate the use of RMN in pediatric VA ablation. RMN showed improved outcomes compared to MAN, resulting in lower VA recurrence and reduced fluoroscopy exposure.

Pocket hematoma after pacemaker or defibrillator surgery: Direct oral anticoagulants versus vitamin K antagonists.

Background: Direct oral anticoagulants (DOACs) are the preferred choice of oral anticoagulation in patients with atrial fibrillation (AF). Randomized trials have demonstrated the efficacy and safety of DOAC in patients undergoing a cardiac implantable electronic device procedure (CIED); however, there is limited real-world data. Objective: To evaluate the outcome of patients undergoing an elective CIED procedure in a tertiary referral center with an interrupted DOAC or continued vitamin K antagonist (VKA) regimen. Methods: This was a retrospective single-center study of consecutive patients with AF undergoing an elective CIED procedure between January 2016 and June 2019. The primary endpoint was a clinically significant pocket hematoma < 30 days after surgery. The secondary endpoint was any systemic thromboembolic complication < 30 days after surgery. Results: Of a total of 1,033 elective CIED procedures, 283 procedures were performed in patients with AF using oral anticoagulation. One-third of the procedures were performed under DOAC (N = 81, 29%) and the remainder under VKA (N = 202, 71%). The DOAC group was younger, had less chronic renal disease, more paroxysmal AF and a lower HAS-BLED score. The VKA group more often underwent a generator change only in comparison to the DOAC group. Clinically significant pocket hematoma occurred in 5 patients (2.5%) in the VKA group and did not occur in the DOAC group (P = 0.33). There were no thromboembolic events reported. Conclusion: In patients with AF undergoing an elective CIED procedure, the risk of a pocket hematoma and a systemic thromboembolic event is comparably low when using either continued VKA or interrupted DOAC.

Description and Genome Characterization of Three Novel Fungal Strains Isolated from Mars 2020 Mission-Associated Spacecraft Assembly Facility Surfaces-Recommendations for Two New Genera and One Species.

National Aeronautics and Space Administration's (NASA) spacecraft assembly facilities are monitored for the presence of any bacteria or fungi that might conceivably survive a transfer to an extraterrestrial environment. Fungi present a broad and diverse range of phenotypic and functional traits to adapt to extreme conditions, hence the detection of fungi and subsequent eradication of them are needed to prevent forward contamination for future NASA missions. During the construction and assembly for the Mars 2020 mission, three fungal strains with unique morphological and phylogenetic properties were isolated from spacecraft assembly facilities. The reconstruction of phylogenetic trees based on several gene loci (ITS, LSU, SSU, RPB, TUB, TEF1) using multi-locus sequence typing (MLST) and whole genome sequencing (WGS) analyses supported the hypothesis that these were novel species. Here we report the genus or species-level classification of these three novel strains via a polyphasic approach using phylogenetic analysis, colony and cell morphology, and comparative analysis of WGS. The strain FJI-L9-BK-P1 isolated from the Jet Propulsion Laboratory Spacecraft Assembly Facility (JPL-SAF) exhibited a putative phylogenetic relationship with the strain Aaosphaeria arxii CBS175.79 but showed distinct morphology and microscopic features. Another JPL-SAF strain, FJII-L3-CM-DR1, was phylogenetically distinct from members of the family Trichomeriaceae and exhibited morphologically different features from the genera Lithohypha and Strelitziana. The strain FKI-L1-BK-DR1 isolated from the Kennedy Space Center facility was identified as a member of Dothideomycetes incertae sedis and is closely related to the family Kirschsteiniotheliaceae according to a phylogenetic analysis. The polyphasic taxonomic approach supported the recommendation for establishing two novel genera and one novel species. The names Aaosphaeria pasadenensis (FJI-L9-BK-P1 = NRRL 64424 = DSM 114621), Pasadenomyces melaninifex (FJII-L3-CM-DR1 = NRRL 64433 = DSM 114623), and Floridaphiala radiotolerans (FKI-L1-BK-DR1 = NRRL 64434 = DSM 114624) are proposed as type species. Furthermore, resistance to ultraviolet-C and presence of specific biosynthetic gene cluster(s) coding for metabolically active compounds are unique to these strains.

Comparison of procedural efficacy, balloon nadir temperature, and incidence of phrenic nerve palsy between two cryoballoon technologies for pulmonary vein isolation: A systematic review and meta-analysis.

INTRODUCTION: In May 2020, a novel cryoballoon system (POLARx; Boston Scientific) became available for catheter ablation of atrial fibrillation (AF). The design of the cryoballoon is comparable to the Arctic Front Advance Pro (AFA-Pro; Medtronic), but it is more compliant during freezing. We compared the procedural efficacy, biophysical parameters, and risk of phrenic nerve palsy (PNP) between the two cryoballoons. METHODS: Embase, MEDLINE, Web of Science, Cochrane, and Google Scholar databases were searched until June 1, 2021 for relevant studies comparing POLARx versus AFA-Pro in patients undergoing pulmonary vein isolation (PVI) for AF. RESULTS: A total of four studies, involving 310 patients were included. There was no difference between the two groups for outcomes regarding procedural efficacy: acute PVI (odds ratio [OR]: 0.43; 95% confidence interval [CI]: 0.06 to 3.03; p = .40), procedure time (mean difference [MD]: 8.15 min; 95% CI: -8.09 to 24.39; p = .33), fluoroscopy time (MD: 1.32 min; 95% CI: -1.61 to 4.25; p = .38) and ablation time (MD: 1.00 min; 95% CI: -0.20 to 2.20; p = .10). The balloon nadir temperature was lower for all individual pulmonary veins (PV) in POLARx compared with AFA-Pro (MD: -9.74°C, -9.98°C, -6.72°C, -7.76°C, for left superior PV, left inferior PV, right superior PV, and right inferior PV, respectively; all p < .001). The incidence of PNP was similar between groups (OR: 0.79; 95% CI: 0.22 to 2.85; p = .72). CONCLUSION: In AF patients undergoing PVI, POLARx and AFA-Pro had a similar procedural efficacy. Balloon nadir temperatures were lower with POLARx, however, the incidence of PNP was similar.

Comparison of procedural efficacy and biophysical parameters between two competing cryoballoon technologies for pulmonary vein isolation: Insights from an initial multicenter experience.

INTRODUCTION: Recently a novel cryoballoon system (POLARx, Boston Scientific) became available for the treatment of atrial fibrillation. This cryoballoon is comparable with Arctic Front Advance Pro (AFA-Pro, Medtronic), however, it maintains a constant balloon pressure. We compared the procedural efficacy and biophysical characteristics of both systems. METHODS: One hundred and ten consecutive patients who underwent first-time cryoballoon ablation (POLARx: n = 57; AFA-Pro: n = 53) were included in this prospective cohort study. RESULTS: Acute isolation was achieved in 99.8% of all pulmonary veins (POLARx: 99.5% vs. AFA-Pro: 100%, p = 1.00). Total procedure time (81 vs. 67 min, p < .001) and balloon in body time (51 vs. 35 min, p < .001) were longer with POLARx. After a learning curve, these times were similar. Cryoablation with POLARx was associated with shorter time to balloon temperature -30°C (27 vs. 31 s, p < .001) and -40°C (32 vs. 54 s, p < .001), lower balloon nadir temperature (-55°C vs. -47°C, p < .001), and longer thawing time till 0°C (16 vs. 9 s, p < .001). There were no differences in time-to-isolation (TTI; POLARx: 45 s vs. AFA-Pro 43 s, p = .441), however, POLARx was associated with a lower balloon temperature at TTI (-46°C vs. -37°C, p < .001). Factors associated with acute isolation differed between groups. The incidence of phrenic nerve palsy was comparable (POLARx: 3.5% vs. AFA-Pro: 3.7%). CONCLUSION: The novel cryoballoon is comparable to AFA-Pro and requires only a short learning curve to get used to the slightly different handling. It was associated with faster cooling rates and lower balloon temperatures but TTI was similar to AFA-Pro.

Reducing radiation exposure in second-generation cryoballoon ablation without compromising clinical outcome.

PURPOSE: Pulmonary vein isolation (PVI) using cryoballoon (CB) ablation is associated with an increased radiation exposure compared with radiofrequency ablation. Previous studies showed that radiation exposure in CB PVI can be reduced by optimizing the fluoroscopy protocol without comprising acute efficacy and safety. We evaluated the mid-term outcome of a modified fluoroscopy protocol in patients undergoing CB PVI. METHODS: The study population comprised 90 consecutive patients who underwent second-generation CB-based PVI. The first 46 patients underwent CB PVI with conventional fluoroscopy settings (group A, historic control group). In the following 44 patients (group B), a modified fluoroscopy protocol was applied consisting of (1) visualization of degree of PV occlusion only by fluoroscopy (no cine runs); (2) increased radiation awareness. Primary endpoints were the total dose area product (DAP), fluoroscopy time, and freedom from documented recurrence of atrial fibrillation (AF) after a single procedure. RESULTS: Group B had a lower median DAP (1393 cGycm2 vs. 3232 cGycm2, P < 0.001) and median fluoroscopy time (20 min vs. 24 min, P < 0.001) as compared with group A. The 1-year freedom from documented recurrence of AF after a single procedure was similar among groups (74% in group A vs. 77% in group B, P = 0.71). There were no significant differences between both groups for the secondary endpoints, including procedure duration, proportion of patients with complete electrical isolation, and complications. CONCLUSION: Using a modified fluoroscopy protocol and increased radiation awareness, radiation exposure can be significantly reduced in CB PVI with a similar 1-year clinical outcome.

Extensive scar modification for the treatment of intra-atrial re-entrant tachycardia in patients after congenital heart surgery.

BACKGROUND: Catheter ablation is an important therapeutic option for atrial tachycardias in patients with CHD. As a result of extensive scarring and surgical repair, multiple intra-atrial re-entrant tachycardia circuits develop and serve as a substrate for arrhythmias. The best ablation approach for patients with multiple intra-atrial re-entrant tachycardias has not been investigated. Here, we compared substrate-based ablation using extensive scar modification to conventional ablation. METHODS: The present study included patients with surgically corrected CHD that underwent intra-atrial re-entrant tachycardia ablation. Extensive scar modification was defined as substrate ablation based on a dense voltage map, aimed to eliminate all potentials in the scar region. The control group had activation mapping-based ablation. A clinical composite endpoint was assessed. Points were given for type, number, and treatment of intra-atrial re-entrant tachycardia recurrence. RESULTS: In 40 patients, 63 (extensive scar modification 13) procedures were performed. Acute procedural success was achieved in 78%. Procedural duration was similar in both groups. Forty-nine percent had a recurrence within 1 year. During a 5-year follow-up (2.5-7.5 years), 46% required repeat catheter ablation. Compared to baseline, clinical composite endpoint significantly decreased by 46% after 12 months (p = 0.001). Acute procedural success, procedural parameters, recurrence and repeat ablation were similar between extensive scar modification and activation mapping-based ablation. CONCLUSION: Catheter ablation using extensive scar modification for intra-atrial re-entrant tachycardias occurring after surgically corrected CHD illustrated similar short- and long-term outcomes and procedural efficiency compared to catheter ablation using activation mapping-based ablation. The choice of ablation approach for multiple intra-atrial re-entrant tachycardia should remain at the discretion of the operator.

Contact feedback improves 1-year outcomes of remote magnetic navigation-guided ischemic ventricular tachycardia ablation.

INTRODUCTION: Remote magnetic navigation (RMN)-guided catheter ablation (CA) is a feasible treatment option for patients presenting with ischemic ventricular tachycardia (VT). Catheter-tissue contact feedback, enhances lesion formation and may consequently improve CA outcomes. Until recently, contact feedback was unavailable for RMN-guided CA. The novel e-Contact Module (ECM) was developed to continuously monitor and ensure catheter-tissue contact during RMN-guided CA. OBJECTIVE: The present study aims to evaluate the effect of ECM implementation on acute and long-term outcomes in RMN-guided ischemic VT ablation. METHOD: This retrospective, two-center study included consecutive ischemic VT patients undergoing RMN-guided CA from 2010 to 2017. Baseline clinical data, procedural data, including radiation times, and acute success rates were compared between CA procedures performed with ECM (ECM+) and without ECM (ECM-). One-year VT-free survival was analyzed using Cox-proportional hazards models, adjusting for potential confounders: age, left ventricular function, VT inducibility at baseline and substrate based ablation strategy. RESULTS: The current study included 145 patients (ECM+ N = 25, ECM- N = 120). Significantly lower fluoroscopy times were observed in the ECM+ group (9.5 (IQR 5.3-13.5) versus 12.5 min (IQR 8.0-18.0), P = 0.025). Non-inducibility of the clinical VT at the end of procedure was observed in 92% ECM+ versus 72% ECM- patients (P = 0.19). ECM guidance was associated with significantly lower VT-recurrence rates during 1-year follow-up (16% ECM+ versus 40% ECM-; multivariable HR 0.29, 95%-CI 0.10-0.69, P = 0.021, reference group: ECM-). CONCLUSION: Contact feedback by the ECM further decreases fluoroscopy exposure and improves VT-free survival in RMN-guided ischemic VT ablation.

Contact-Force-Sensing-Based Radiofrequency Catheter Ablation in Paroxysmal Supraventricular Tachycardias (COBRA-PATH): a randomized controlled trial.

BACKGROUND: Multiple studies have demonstrated the importance of adequate catheter-tissue contact in the creation of effective lesions during radiofrequency catheter ablation. The development of contact force (CF)-sensing catheters has contributed significantly to improve clinical outcomes in atrial fibrillation. However, CF-sensing technology is not used in the ablation of paroxysmal supraventricular tachycardia (PSVT). The possible reason for this is that PSVT ablation with the conventional approach (i.e. nonirrigated, non-CF-sensing catheters) is considered a relatively low-risk procedure with fairly high success rates (short and long term). The aim of this study is to determine whether CF sensing can further improve the outcomes of PSVT ablation. METHODS/DESIGN: The COBRA-PATH study is a single-center, two-armed, randomized controlled trial. Patients without structural heart disease being referred for electrophysiology study, because of PSVT and potential treatment with radiofrequency (RF) catheter ablation, will be randomly assigned to either manual ablation with standard nonirrigated ablation catheters or manual ablation with an open-irrigated ablation catheter equipped with CF sensing (used in a virtual nonirrigated modus). The primary study endpoint is the difference in the number of RF applications during the ablation of atrioventricular nodal re-entry tachycardia, and that of Wolff-Parkinson-White syndrome and atrioventricular re-entrant tachycardia. Secondary outcome parameters include acute and long-term procedural success rates, overall duration of RF applications, procedure/fluoroscopy durations and safety parameters. DISCUSSION: We expect to see a reduced number/duration of RF applications required to achieve effective lesion creation, and consequently a decrease in total procedure/fluoroscopy times. Although a significant improvement in procedural success rates (acute/long term) might not be feasible to demonstrate (given the relatively high success rate of the standard ablation method), the possible decrease in procedure duration and the consequential reduction of radiation exposure has important clinical implications for both operators and patients undergoing the procedure. TRIAL REGISTRATION: ClinicalTrials, NCT04078685. Retrospectively registered on 2 September 2019.

Predicting defibrillator benefit in patients with cardiac resynchronization therapy: A competing risk study.

BACKGROUND: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in selected heart failure patients, but decision-making regarding selection of CRT-defibrillator or CRT-pacemaker is an ongoing debate. OBJECTIVE: The purpose of this study was to construct predictive models and scoring systems for implantable cardioverter-defibrillator (ICD) therapy and death without ICD therapy (prior death). METHODS: We pooled 2 prospective cohorts of CRT-D patients with primary prevention indication and used Fine and Gray models to develop independent prognostic models for time to first ICD therapy (event of interest) or death without prior ICD therapy (competing event). We defined CRT-D benefit as a high probability of ICD therapy combined with moderate/low probability of prior death. RESULTS: Seven hundred twenty patients were included. Median follow-up was 7.2 years, and 247 patients (34%) died. Cumulative incidence of ICD therapy/prior death at 5 years was 24%/17%. In multivariable models, higher New York Heart Association classes, diuretic use, and ischemic cardiomyopathy were predictors of ICD therapy (hazard ratio 1.89 [1.30-2.75], 1.91 [1.12-3.24], and 1.40[1.02-1.92], respectively) but not of prior death. Males with comorbidities (cancer, renal failure, peripheral artery disease, body mass index >30) or systolic blood pressure ≤100 were at higher risk for prior death. Higher age was associated with lower risk of ICD therapy but higher risk of prior death. One-quarter of patients had low predicted benefit from CRT-D implantation using a scoring system for the dual prediction of appropriate ICD therapy and death without appropriate ICD-therapy. CONCLUSION: Different factors predict ICD therapy or prior death in CRT-D patients using competing risk models. Scoring allows identifying patients with predicted low benefit of CRT-D (low chance of ICD therapy, high chance of prior death).

Clinical research: remote magnetic navigation vs. manually controlled catheter ablation of right ventricular outflow tract arrhythmias: a retrospective study.

Aims: Remote magnetic navigation (RMN) is an alternative to manual catheter control (MCC) radiofrequency ablation of right ventricular outflow tract (RVOT) arrhythmias. The data to support RMN approach is limited. We aimed to investigate the clinical and procedural outcomes in a cohort of patients undergoing RVOT premature ventricular complex/ventricular tachycardia (PVCs/VT) ablation procedures using RMN vs. MCC. Methods and results: Data was collected from two centres. Eighty-nine consecutive RVOT PVCs/VT ablation procedures were performed in 75 patients; RMN: 42 procedures and MCC: 47 procedures. CARTOXPTM or CARTO3 (Biosense Webster) was used for endocardial mapping in 19/42 (45%) in RMN group and 28/47 (60%) in MCC group; EnSiteTM NavXTM (St. Jude Medical) was used in the rest of the cohort. Stereotaxis platform (Stereotaxis Inc., St. Louis, MO, USA) was used for RMN approach. Procedural time was 113 ± 53 min in the RMN group and 115 ± 69 min in MCC (P = 0.90). Total fluoroscopic time was 10.9 ± 5.8 vs. 20.5 ± 13.8 (P < 0.05) and total ablation energy application time 7.0 ± 4.7 vs 11.9 ± 16 (P = 0.67) accordingly. There were two complications in RMN group and five in MCC (P = 0.43). Acute procedural success rate was 80% in RMN vs. 74% in MCC group (P = 0.46). After a median follow-up of 25 months (interquartile range 13-34), the success rate remained 55% in the RMN group and 53% in MCC (P = 0.96). Conclusion: Right ventricular outflow tract arrhythmia ablations were performed using half of fluoroscopic times with Stereotaxis platform RMN compared to manual approach. Acute and chronic success rates as well as complication rates were not significantly different.