Repeat pulmonary vein isolation and anterior line ablation using a novel point-by-point pulsed-field ablation system

BACKGROUND

Pulsed-field ablation (PFA) is a nonthermal energy source for ablation of cardiac arrhythmias. This study investigated the prospective outcomes of a novel PFA generator in conjunction with a commercially available, contact force-sensing, focal ablation catheter.

OBJECTIVE

The purpose of this study was to assess the feasibility, safety, and lesion characteristics of point-by-point PFA in consecutive patients undergoing repeat ablation of atrial fibrillation (AF).

METHODS

The study involved reisolation of pulmonary veins (PVs) with electrical reconnection and the creation of an anterior line (AL) in patients with anterior substrate or durable pulmonary vein isolation (PVI).

RESULTS

In 24 patients (46% female; mean age 67 ± 10 years; 67% persistent AF), successful reisolation of 27 of 27 reconnected PVs (100%) was performed. In 19 patients, AL ablation was performed, with bidirectional block in 16 (84%), median ablation time 26 [21, 33] minutes, and first-pass bidirectional block in 13 patients (68%). Acute AL reconduction occurred in 8 of 19 patients (42%). Among these 8 patients, a subsequent sustained block of the AL was achieved in 5 (63%). Ultra-high-density electroanatomic mapping revealed homogeneous but relatively large low-voltage areas in the ablated regions. Median procedural, left atrial dwell, and fluoroscopy times were 100 [90, 109] minutes, 83 [75, 98] minutes, and 10 [8, 13] minutes, respectively. No major or minor complications occurred.

CONCLUSION

This study demonstrated feasibility, acute efficacy, and safety of point-by-point PFA for repeat PVI and AL ablation. Further studies are warranted to assess the long-term durability and comparison with established ablation methods.

Management of pericardial tamponade in the electrophysiology laboratory: results from a national survey

BACKGROUND

Despite continued efforts to improve the safety of catheter ablation, pericardial tamponade remains one of its more frequent, potentially life-threatening complications. Management of cardiac tamponade is not standardized and uncertainties regarding acute treatment remain.

METHODS

This survey sought to evaluate the management of cardiac tamponade in German EP centers via a standardized postal questionnaire. All 341 identified German EP centers were invited to return a questionnaire on their standards for the management of cardiac tamponade.

RESULTS

A total of 189 German EP centers completed the questionnaire. Several precautions are followed to avoid pericardial tamponade: A minority of centers preclude very old patients (19%) or those with a high body mass index (30%) from ablation. Non-vitamin K antagonist oral anticoagulants are briefly paused in most centers (88%) before procedures, while vitamin K antagonists are continued. Pericardial tamponade is usually treated using reversal of heparin by applying protamine (86%) and pericardiocentesis under both, fluoroscopic and echocardiographic guidance (62%). A pigtail catheter is mostly inserted (97%) and autotransfusion of aspirated blood is performed in 47% of centers. The decision for surgical repair depends on different clinical and infrastructural aspects. The timing of reinitiation of anticoagulation widely differs between the centers. Approximately 1/3 of centers prescribe nonsteroidal anti-inflammatory agents, colchicine or steroids after pericardiocentesis.

CONCLUSION

The present survey shows that the management of cardiac tamponade is still inhomogeneous in German ablation centers. However, multiple findings of this survey can be generalized and might guide especially less experienced operators and centers in their treatment and decision strategies.

The infrastructure of electrophysiology centers impacts the management of cardiac tamponade-Results from a national survey

BACKGROUND

Although electrophysiological (EP) centers have institutional standards, evidence on management of cardiac tamponade is lacking.

AIM AND METHODS

A physician-based survey was conducted by sending out questionnaires to all hospitals in Germany performing EP procedures. To evaluate the infrastructure of EP centers and the impact of center volume and onsite cardiac surgery on the management of cardiac tamponade, the results of the survey were analyzed for low-volume (0-250 procedures per year), mid-volume (250-500 procedures), and high-volume (>500 procedures) centers, as well as for centers with and without onsite cardiac surgery.

RESULTS

A total of 341 centers were identified and 189/341 (55%) returned data sets were analyzed. Most types of EP procedures are performed across all kinds of centers. Ablation of ventricular tachycardia (VT) is concentrated in higher volume centers and in centers with onsite cardiac surgery. None of the participating low-volume centers and only 13% of centers without onsite cardiac surgery responded to performing epicardial VT ablation. Irrespective of center volume and onsite cardiac surgery, neither body mass index nor age was reported to be an exclusion criterion for ablation procedures. Higher volume centers and centers with onsite cardiac surgery more often have dedicated EP laboratories and EP-nursing teams. Also, differences regarding periprocedural safety precautions and management of cardiac tamponade were found for low-, mid-, and high-volume centers, as well as for centers with and without onsite cardiac surgery.

CONCLUSION

While center volume and onsite cardiac surgery do not impact patient selection, there are differences in ablation spectrum, infrastructure, periprocedural safety precautions, and treatment of tamponade.

Acute lesion extension following pulmonary vein isolation with two novel single shot devices: Pulsed field ablation versus multielectrode radiofrequency balloon

INTRODUCTION

Pulsed-field ablation (PFA) and the multielectrode radiofrequency balloon (RFB) are two novel ablation technologies to perform pulmonary vein isolation (PVI). It is currently unknown whether these technologies differ in lesion formation and lesion extent. We compared the acute lesion extent after PVI induced by PFA and RFB by measuring low-voltage area in high-density maps and the release of biomolecules reflecting cardiac injury.

METHODS

PVI was performed with a pentaspline catheter (FARAPULSE) applying PFA or with the compliant multielectrode RFB (HELIOSTAR). Before and after PVI high-density mapping with CARTO 3 was performed. In addition, blood samples were taken before transseptal puncture and after post-PVI remapping and serum concentrations of high-sensitive Troponin I were quantified by immunoassay.

RESULTS

Sixty patients undergoing PVI by PFA (n = 28, age 69 ± 12 year, 60% males, 39.3% persistent atrial fibrillation [AF]) or RFB (n = 32, age 65 ± 13 year, 53% males, 21.9% persistent AF) were evaluated. Acute PVI was achieved in all patients in both groups. Mean number of PFA pulses was 34.2 ± 4.5 and mean number RFB applications was 8.5 ± 3 per patient. Total posterior ablation area was significantly larger in PFA (20.7 ± 7.7 cm²) than in RFB (7.1 ± 2.09 cm²; p < .001). Accordingly, posterior ablation area for each PV resulted in larger lesions after PFA versus RFB (LSPV 5.2 ± 2.7 vs. 1.9 ± 0.8 cm², LIPV 5.5 ± 2.3 vs. 1.9 ± 0.8 cm², RSPV 4.7 ± 1.9 vs. 1.6 ± 0.5 cm², RIPV 5.3 ± 2.1 vs. 1.6 ± 0.7 cm,² respectively; p < .001). In a subset of 38 patients, increase of hsTropI was higher after PFA (625 ± 138 pg/mL, n = 28) versus RFB (148 ± 36 pg/mL, n = 10; p = .049) supporting the evidence of larger lesion extent by PFA.

CONCLUSION

PFA delivers larger acute lesion areas and higher troponin release upon successful PVI than multielectrode RFB-based PVI in this single-center series.

The effects of menstrual cycle phases on immune function and inflammation at rest and after acute exercise: A systematic review and meta-analysis

The immune system plays an important role in mediating exercise responses and adaptations. However, whether fluctuating hormone concentrations across the menstrual cycle may impact these processes remains unknown. The aim of this systematic review with meta-analysis was to compare baseline concentrations as well as exercise-induced changes in immune and inflammatory parameters between menstrual cycle phases. A systematic literature search was conducted according to the PRISMA guidelines using Pubmed/MEDLINE, ISI Web of Science, and SPORTDiscus. Of the 159 studies included in the qualitative synthesis, 110 studies were used for meta-analysis. Due to the designs of the included studies, only the follicular and luteal phase could be compared. The estimated standardized mean differences based on the random-effects model revealed higher numbers of leukocytes (-0.48 [-0.73; -0.23], p < 0.001), monocytes (-0.73 [-1.37; -0.10], p = 0.023), granulocytes (-0.85 [-0.1.48; -0.21], p = 0.009), neutrophils (-0.32 [-0.52; -0.12], p = 0.001), and leptin concentrations (-0.37 [-0.5; -0.23], p = 0.003) in the luteal compared to the follicular phase at rest. Other parameters (adaptive immune cells, cytokines, chemokines, and cell adhesion molecules) showed no systematic baseline differences. Seventeen studies investigated the exercise-induced response of these parameters, providing some indications for a higher pro-inflammatory response in the luteal phase. In conclusion, parameters of innate immunity showed cycle-dependent regulation at rest, while little is known on the exercise responses. Due to a large heterogeneity and a lack of cycle phase standardization among the included studies, future research should focus on comparing at least three distinct hormonal profiles to derive more specific recommendations for exercise prescription.

Novel Radiofrequency Balloon Catheter - Impact of Ablation Parameters on Single-Shot Isolation

BACKGROUND

A novel multielectrode radiofrequency balloon (RFB) catheter has been released for pulmonary vein isolation (PVI).Methods and Results: In this observational study consecutive patients with drug-refractory paroxysmal or persistent atrial fibrillation (AF) undergoing first-time PVI were enrolled in 2 high-volume ablation centers. All procedures were conducted in conjunction with a 3D-mapping system. Clinical, procedural and ablation parameters were systematically analyzed. 105 patients (58% male; 52% paroxysmal AF, 68±11.3 years mean age, left atrial volume index 38.6±14.8 mL/m²) were included. 241/412 (58.5%) PVs were successfully isolated with a single shot (SS), with a time-to-isolation of 11.6±8 s. Total number of radiofrequency applications was 892 (mean 2.2/PV), resulting in successful isolation of 408/412 (99%) PVs at the end of the procedure. Mean electrodes' impedance drop was significantly higher in the SS-PVI compared with non-SS applications (21.5±6.6 vs. 18.6±6.5 Ohm). Concordantly, higher temperature rise was observed in the SS vs. non-SS applications (10.9±4.9℃ vs. 9.6±4.7℃).

CONCLUSIONS

In this multicenter real-world study, mean impedance drop and temperature rise were associated with successful SS-PVI applying the novel RFB catheter. These parameters may help to guide efficient usage of the new RF balloon.

A novel saline-based occlusion tool allows for dye-less cryoballoon-based pulmonary vein isolation and fluoroscopy reduction

Background

Cryoballoon (CB)- based pulmonary vein isolation (PVI) remains guided by fluoroscopy and dye. The novel saline injection-based occlusion tool allows for pulmonary vein (PV)-occlusion assessment without the need for dye injection.

Aim

To compare KODEX-EPD guided CB-PVI using the novel saline injection-based workflow with conventional cryoablation for acute efficacy, fluoroscopy exposure and dye volume.

Methods

Consecutive atrial fibrillation (AF)- patients undergoing CB-PVI in conjunction with KODEX-EPD (Cryo^EPD group) were analyzed. Patients undergoing conventional CB-PVI (Cryo group) in the same time period acted as controls.

Results

One hundred forty patients [91/140 (65%) persistent AF] were studied. Seventy patients underwent Cryo^EPD procedures [64 ± 13 years, 21 (30%) female] and seventy patients underwent Cryo procedures [68 ± 10 years, 27 (39%) female].A total of 560 PVs were identified and successfully isolated. Mean procedure time was 66 ± 15 min for the Cryo^EPD group, and 65 ± 19 min for the Cryo group (p = 0.3). Fluoroscopy time (Cryo^EPD 6 ± 4 min; Cryo 13 ± 6 min, p < 0.001) and dose area product (Cryo^EPD 193 [111; 297] cGycm²; Cryo 381 [268; 614] cGycm², p < 0.001) were lower in patients undergoing Cryo^EPD compared with Cryo procedures. No dye was needed in the Cryo^EPD group while 53 ± 18 ml dye per patient were administered for the Cryo group (p < 0.001). The overall complication rate was comparable between both groups (p = 0.5).

Conclusion

KODEX-EPD guided AF-ablation enables dye-free CB-based PVI with reduced fluoroscopy exposure when compared to conventional CB-ablation, without differences in acute procedural outcomes or procedure duration.

Assessing the World Health Organization: What does the academic debate reveal and is it democratic?

The World Health Organization (WHO), the leading global authority in public health, routinely attracts loud calls for reform. Although Member States negotiate reform internally, academic debate is more public, and can generate ideas and provide independent accountability. We investigate why authors advocate for WHO reform so commonly. We wondered if this literature had potentially useful themes for WHO, what methods and evidence were used, and we wanted to analyze the geography of participation. We conducted a systematic review using four databases to identify 139 articles assessing WHO or advocating for reform. We discuss these using categories we derived from the management literature on organizational performance. We also analyzed evidence, country of origin, and topic. The literature we reviewed contained 998 claims about WHO's performance or reform, although there were no standard methods for assessing WHO. We developed a framework to analyze WHO's performance and structure a synthesis of the claims, which find WHO imperiled. Its legitimacy and governance are weakened by disagreements about purpose, unequal Member State influence, and inadequate accountability. Contestation of goals and strategies constrain planning. Structure and workforce deficiencies limit coordination, agility, and competence. WHO has technical and normative authority, but insufficient independence and legal power to influence uncooperative states. WHO's identity claims transparency, independence, and courage, but these aspirations are betrayed in times of need. Most articles (88%) were commentaries without specified methods. More than three-quarters (76%) originated from the US, the UK, or Switzerland. A quarter of papers (25%) focused on international infectious disease outbreaks, and another 25% advocated for WHO reform generally. Many criticisms cite wide-ranging performance problems, some of which may relate to obstructive behavior by Member States. This literature is incomplete in the geographic representation of authors, evidence, methods, and topics. We offer ideas for developing more rigorous and inclusive academic debate on WHO.

Temperature-controlled ablation of the mitral isthmus line using the novel DiamondTemp ablation system

Background

The novel DiamondTemp™ (DT)-catheter (Medtronic^®) was designed for high-power, short-duration ablation in a temperature-controlled mode.

Aim

To evaluate the performance of the DT-catheter for ablation of the mitral isthmus line (MIL) using two different energy dosing strategies.

Materials and methods

Twenty patients with recurrence of atrial fibrillation (AF) and/or atrial tachycardia (AT) following pulmonary vein (PV) isolation were included. All patients underwent reisolation of PVs in case of electrical reconnection and ablation of a MIL using the DT-catheter. Application durations of 10 (group A, n = 10) or 20 s (group B, n = 10) were applied. If bidirectional block was not reached with endocardial ablation, additional ablation from within the coronary sinus (CS) was conducted.

Results

In 19/20 (95%) patients, DT ablation of the MIL resulted in bidirectional block. Mean procedure and fluoroscopy time, and dose area product did not differ significantly between the two groups. In group B, fewer radiofrequency applications were needed to achieve bidirectional block of the MIL when compared to group A (26 ± 12 vs. 42 ± 17, p = 0.04). Ablation from within the CS was performed in 8/10 patients (80%) of group A and in 5/10 (50%) patients of group B (p = 0.34). No major complication occurred.

Conclusion

Mitral isthmus line ablation with use of the DT-catheter is highly effective and safe. Longer radiofrequency-applications appear to be favorable without compromising safety.

Pulsed-field ablation-based pulmonary vein isolation: acute safety, efficacy and short-term follow-up in a multi-center real world scenario

PURPOSE

Pulsed-field ablation (PFA) is a new energy source to achieve pulmonary vein isolation (PVI) by targeted electroporation of cardiomyocytes. Experimental and controlled clinical trial data suggest good efficacy of PFA-based PVI. We aimed to assess efficacy, safety and follow-up of PFA-based PVI in an early adopter routine care setting.

METHODS

Consecutive patients with symptomatic paroxysmal or persistent atrial fibrillation (AF) underwent PVI using the Farawave® PFA ablation catheter in conjunction with three-dimensional mapping at two German high-volume ablation centers. PVI was achieved by applying 8 PFA applications in each PV.

RESULTS

A total of 138 patients undergoing a first PVI (67 ± 12 years, 66% male, 62% persistent AF) were treated. PVI was achieved in all patients by deploying 4563 applications in 546 PVs (8.4 ± 1.0/PV). Disappearance of PV signals after the first application was demonstrated in 544/546 PVs (99.6%). More than eight PFA applications were performed in 29/546 PVs (6%) following adapted catheter positioning or due to reconnection as assessed during remapping. Mean procedure time was 78 ± 22 min including pre- and post PVI high-density voltage mapping. PFA catheter LA dwell-time was 23 ± 9 min. Total fluoroscopy time and dose area product were 16 ± 7 min and 505 [275;747] cGy*cm². One pericardial tamponade (0.7%), one transient ST-elevation (0.7%) and three groin complications (2.2%) occurred. 1-year follow-up showed freedom of arrhythmia in 90% in patients with paroxysmal AF (n = 47) and 60% in patients with persistent AF (n = 82, p = 0.015).

CONCLUSIONS

PFA-based PVI is acutely highly effective and associated with a beneficial safety and low recurrence rate.

Novel cryoballoon ablation system for pulmonary vein isolation: multicenter assessment of efficacy and safety-ANTARCTICA study

AIMS

Pulmonary vein isolation (PVI) either by balloon devices or radiofrequency forms the cornerstone of invasive atrial fibrillation (AF) treatment. Although equally effective cryoballoon (CB)-based PVI offers shorter procedure duration and a better safety profile. Beside the worldwide established Arctic Front Advance system, a novel CB device, POLARx, was recently introduced. This CB incorporates unique features, which may translate into improved efficacy and safety. However, multicentre assessment of periprocedural efficacy and safety is lacking up to date.

METHODS AND RESULTS

A total of 317 patients with paroxysmal or persistent AF were included and underwent POLARx CB-based PVI in 6 centres from Germany and Italy. Acute efficacy and safety were assessed in this prospective multicenter observational study. In 317 patients [mean age: 64 ± 12 years, 209 of 317 (66%) paroxysmal AF], a total of 1256 pulmonary veins (PVs) were identified and 1252 (99,7%) PVs were successfully isolated utilizing mainly the short tip POLARx CB (82%). The mean minimal CB temperature was -57.9 ± 7°C. Real-time PVI was registered in 72% of PVs. The rate of serious adverse events was 6.0% which was significantly reduced after a learning curve of 25 cases (9.3% vs. 3.0%, P = 0.018). The rate of recurrence-free survival after mean follow-up of 226 ± 115 days including a 90-day blanking period was 86.1%.

CONCLUSION

In this large multicentre assessment, the novel POLARx CB shows a promising efficacy and safety profile after a short learning curve.

Revival of the Forgotten

Pulmonary vein (PV) isolation (PVI) by continuous, transmural and durable lesions is decisive for ensuring long-term freedom from atrial fibrillation (AF). AF ablation requires irrigated tip catheters to reduce thromboembolic complications. This precluded temperature-controlled delivery of radiofrequency (RF) energy.The aim of this study was to evaluate feasibility, acute efficacy, and safety of an irrigated, temperature-controlled ablation catheter [DiamondTemp™ (DT) Medtronic^®] for PVI.Consecutive patients with AF underwent PVI using the DT catheter combined with high-power short-duration RF applications. Ablation settings were (1) a catheter tip temperature limit of 60°C, (2) a temperature-controlled power of 50 W, and (3) application duration of 10 seconds. The primary endpoint was acute isolation of PVs, reassessed after a 30-minute waiting period. Secondary endpoints included procedural parameters (defined as a catheter tip temperature of 50°C > 3 seconds, an impedance drop of 5-10 Ω) and the occurrence of serious adverse events.Fifty consecutive patients [mean age 66 ± 12 years, 38 (76%) women, 24 patients with paroxysmal AF (48%)] were included. Median procedure and left atrial dwell time was 89 [68; 107] and 63 [52; 79] minutes, respectively. Mean number of RF applications was 59 ± 20, and mean total RF duration was 14 ± 6 minutes. Acute PVI was achieved in all patients solely using DT ablation. Acute PV reconnection within the waiting period occurred in five patients; all reconnected PVs were successfully reisolated. One major complication occurred.In this study, the DT ablation system demonstrated high acute efficacy for PVI. Temperature-controlled ablation in conjunction with high-power short-duration applications might be effectively supported.

Ablation of Outflow Tract Arrhythmias in Patients With and Without Structural Heart Disease—A Comparative Analysis

Introduction

Catheter ablation of ventricular arrhythmias emerging from the ventricular outflow tracts and adjacent structures is very effective and considered almost curative in patients without structural heart disease (SHD). Outcomes of patients with SHD undergoing ablation of outflow tract arrhythmias are not known.

Methods

Consecutive patients (2019–2021) undergoing catheter ablation of ventricular arrhythmias in a single high-volume center were retrospectively analyzed. Patients with ablation of outflow tract arrhythmias were identified and divided in individuals with and without SHD. Procedural parameters and acute outcome were compared.

Results

We identified 215 patients with outflow tract arrhythmias (35.3% female, mean age 58.3 ± 16.0 years). Of those, 93 (43.3%) had SHD. Patients with SHD and outflow tract arrhythmias were older (65.0 ± 12.8 vs. 53.3 ± 16.3 years; p < 0.001), more often male (82.8 vs. 50.0%; p < 0.001) and had more comorbidities than patients without SHD (arterial hypertension: 62.4 vs. 34.4%, p < 0.001; diabetes: 22.6 vs. 8.2%, p = 0.005; chronic lung disease: 20.4 vs. 7.4%, p = 0.007). Outflow tract arrhythmias in patients with SHD had their origin more often in the left ventricle (68.8 vs. 53.3%, p = 0.025). The acute success rate was similar in both patient groups (93.4 vs. 94.2%, p = 0.781). Patients with SHD were discharged later {median length of hospital stay with SHD 5 [6 (interquartile range)] days, without SHD 2 [4] days, p < 0.001}. Periprocedural complications were numerically more frequent in patients with SHD [with SHD 12 (12.9%), without SHD 8 (6.6%), p = 0.154].

Conclusion

Outflow tract arrhythmia ablation has a high success rate irrespective of the presence of SHD. Longer hospital stay and potentially a higher risk of periprocedural complications should be considered when discussing this treatment option with patients.

Comparison of left atrial lesion size and troponin release of two novel single shot devices for pulmonary vein isolation: pulsed field ablation vs. multi-electrode radiofrequency balloon

Funding Acknowledgements

Type of funding sources: None.

Introduction

Pulsed-field ablation (PFA) and the multi-electrode radiofrequency balloon (RFB) are two novel ablation technologies to perform pulmonary vein isolation (PVI). It is currently unknown whether these technologies differ in lesion formation and lesion extent.

Purpose

We compared the acute lesion extent after PVI induced by PFA and RFB by measuring low-voltage area in high-density maps and the release of biomolecules reflecting cardiac injury.

Methods

PVI was performed with a pentaspline catheter (FARAPULSE) applying PFA or with the compliant multi-electrode radiofrequency balloon (HELIOSTAR). Before and after PVI high-density mapping with CARTO3 was performed. In addition, blood samples were taken before transseptal puncture and after post-PVI remapping. Serum concentrations of high-sensitive Troponin I (hsTropI) were quantified by Immunoassay.

Results

50 patients undergoing PVI by PFA (n=26, age 71±10 y, 58% males, 58% persistent AF) or RFB (n=24; age 64±13 y, 54% males, 25% persistent AF) were evaluated. Acute PVI was achieved in all patients in both groups. Mean number of PFA pulses were n=34±5 and mean number RFB applications were n=8±3. Total posterior ablation area was bigger in PFA (19.0±6.2 cm²) than in RFB (9.0±2.2 cm²; p&lt;0.001). The posterior distance between septal and lateral lesions was shorter in PFA (23.7±10.5 mm) than in RFB (30.0±7.3 mm; p=0.021). In a total of 38 patients increase of hsTropI was higher after PFA (625±138 pg/ml, n=28) vs. RFB (148±36 pg/ml; n=10; p=0.049) supporting the evidence of larger lesion extent by PFA.

Conclusion

Pulse-field ablation delivers larger acute lesion areas and higher troponin release upon successful pulmonary vein isolation than multi-electrode array balloon-based pulmonary vein isolation in this single-center series.

Shortened fluoroscopy duration and reduced use of contrast dye in cryoballoon-based pulmonary vein isolation procedures using KODEX-EPD’s novel occlusion tool

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Study grant by EPD Solutions, Philips, Netherlands

Background

The occlusion tool was recently introduced for KODEX-EPD which is a novel dielectric high-resolution cardiac imaging system. The occlusion tool provides information about level of pulmonary vein occlusion by the cryoballoon (CB) in CB-based pulmonary vein isolation (PVI) ablation procedures for atrial fibrillation (AF).

Purpose

Assess effects of the introduction of the occlusion tool on procedural parameters during CB-PVI such as feasibility, acute efficacy and periprocedural safety of KODEX-EPD in different software versions.

Methods and Results

173 consecutive patients (60/173 (35%) paroxysmal AF, 64±12 years, 66/173 (38%) female) underwent CB-PVI with EPD imaging between 08/2019 and 10/2021. 38/173 (22%) of all patients were treated using software version 1.4.6, 33/173 (19%) patients with version 1.4.6a, 41/173 (24%) patients with version 1.4.7 and 61/173 (35%) patients with the latest version 1.4.8. Acute PVI was achieved in all patients. No major periprocedural complications were documented. Software version showed significant effects on procedure duration, fluoroscopy duration and dose area product in ANOVA testing (Figure 1A-C). The largest effect in post-hoc testing was observed for fluoroscopy duration (Figure 1B). Tobit regressions were fitted to model effects of software version on the censored variable contrast volume. All software versions predicted used contrast volume (p&lt;0.00748, Figure 1D). Modelling only effects of procedure date on contrast volume was less accurate than for software version (r²=0.057, p for procedure date = 0.0031) and also a Likelihood-Ratio-Test between different regression models underlined significant effects of software version (p&lt;0.0001).

Conclusion

CB-based PVI in combination with its PV-occlusion tool is feasible and safe. The present data strongly suggests a steady positive development of the novel wide-band dielectric imaging and mapping system towards a fluoroscopy- and dye-reduced CB-based AF-ablation. Software versions were introduced sequentially. Therefore time (procedure date) needs to be considered as the most relevant confounder of the described results (e.g. due to a learning curve using the system). However, differentiated statistical testing could show that the results are mainly explained by software version and only much weaker by procedure date.

Catheter ablation of the mitral isthmus line using the novel DiamondTemp ablation system: first experience using two different ablation protocols

Funding Acknowledgements

Type of funding sources: None.

Background

Mitral ishmus ablation is an established approach to treat perimitral reentrant tachycardia, and is often performed as substrat modification in patients with persistent atrial fibrillation (AF). Bidirectional block of the mitral isthmus line (MIL) is still a great challenge using conventional ablation catheters, but is essential to prevent recurrence of atrial arrhythmia.

Recently, the novel DiamondTempTM (DT) ablation system was introduced and allows for high-power, short-duration ablation in a temperature-controlled mode. Its use during pulmonary vein isolation (PVI) using a recommended ablation setting with a catheter-tip temperature limit of 60°C, a temperature-controlled power of 50 W and an application duration of 10 sec has shown to be effective and safe. However, data on DT ablation settings for substrate modification, i.e., creation of linear lesions are lacking.

Aim

The aim of the present study was to evaluate acute efficacy and safety of the novel DT ablation system for bidirectional block of the MIL using two different protocols.

Methods

The study population comprised 14 patients [67±8 years, 10/14 male (71%)] suffering from persistent AF and/or atrial tachycardia who underwent catheter re-ablation with creation of a MIL using the DT ablation system. Ablation settings were a catheter-tip temperature limit of 60°C, a temperature-controlled power of 50 W with an application duration of either 10 sec (group A, n=7) or 20 sec (group B, n=7). Additional epicardial ablation from within the coronary sinus with a temperature limit of 60°C, a temperature-controlled power of 20 W and an application duration of 20 sec was performed, if bidirectional block could not be achieved with endocardial ablation only.

Results

Mean procedure and fluoroscopy time, and dose area product for group A and group B were 103±24 vs. 119±38 min, 12±5 vs. 13±4 min, and 572±270 vs. 537±202 cGycm, respectively. Bidirectional block of the MIL was achieved in 7/7 (100%) patients in group A and in 6/7 (86%) patients in group B. Additional epicardial ablation was required in 6/7 patients (86%) in group A and in 4/7 (57%) patients in group B. In group B, bidirectional block of the MIL required fewer endocardial (31±11 vs. 26±10 applications) as well as epicardial RF-applications (10±6 vs. 7±3 applications). Pericardial effusion without hemodynamic relevance occurred in 1/7 (14%) patients of group B. No further complications occurred.

Conclusion

Catheter ablation of the MIL using the novel DT ablation system is safe and associated with high acute efficacy. A lower number of RF-applications and a less frequent need for additional epicardial ablation was observed when applying longer RF-applications of 20 sec. Further analyses are warranted to confirm these findings.

Optimizing catheter ablation of atrial fibrillation by a novel wide-band dielectric imaging system: first experience on real-time wall thickness measurement

Funding Acknowledgements

Type of funding sources: None.

Background

Conventional mapping systems do not provide wall-thickness data, which is, however, known to be a determinant of radiofrequency ablation lesion transmurality. KODEX-EPD is a novel open-platform system, which uses dielectric tissue properties to provide real-time, high-resolution cardiac images, tissue characteristics and wall-thickness measurement to guide ablation procedures.

Aim

The aim of this case series was to report on our first experiences with KODEX-EPD regarding estimation of myocardial wall-thickness during catheter ablation of atrial fibrillation (AF).

Methods

We retrospectively analyzed consecutive patients undergoing radiofrequency AF-ablation in combination with KODEX-EPD. A high-resolution image from the left atrium (LA) and the pulmonary veins (PV) was obtained prior to ablation using a spiral mapping catheter in conjunction with KODEX-EPD. Wall-viewer points were collected within the LA, the PVs and the left atrial appendage (LAA) using a standard radiofrequency non-contact force ablation catheter and analyzed for wall-thickness applying the latest KODEX-EPD software version (1.5.0, not yet commercially released). Wall-viewer points were divided into a total of 10 segments (PV ostia, anterior wall, posterior wall, LA roof, LA floor, LAA and PV carina, details see Figure 1) in order to characterize wall-thickness in respective areas.

Results

A total of 570 wall-viewer points in 5 patients were analyzed. Most of the wall-viewer points were collected at the PV ostia as well as along the posterior and anterior wall (449/570, 79%). Actual myocardial atrial thickness ranged from 1.6 to 3.9 mm. Thickest myocardial LA-tissue was measured at the anterior wall (median 3.1 mm) and thinnest at the LA-roof (median 2.2 mm). Figure 2 gives a detailed distribution of wall-thickness measurements at different sites in the LA and PVs.

Conclusion

Atrial wall thickness can be estimated in patients during AF ablation procedures using dielectric tissue properties. Further evaluation and validation of the method are needed to study its reliability and utility for clinical practice.

The established and the challenger: A direct comparison of current cryoballoon technologies for pulmonary vein isolation

INTRODUCTION

Cryoballoon (CB) ablation for pulmonary vein isolation (PVI) is an effective treatment of atrial fibrillation (AF). Recently, a novel cryoablation system was introduced. The aim of the study was to compare the safety, efficacy and biophysical characteristics of a novel cryoablation system (POLARx™; Boston Scientific) to a commonly used and clinically well characterized system (Arctic Front Advance Pro™, AFA; Medtronic).

METHODS AND RESULTS

Fifty consecutive patients with symptomatic AF, who underwent CB-based ablation with the POLARx were compared to 50 consecutive patients treated with the AFA. Acute PVI was achieved in 99.8% (POLARx 99.5%, AFA 100%, p = 1.00). Time to isolation (TTI) was comparable in both groups (POLARx 35 [27, 48] s, AFA 30 [21, 43] s, p = 0.165). The POLARx showed a lower balloon temperature at TTI (POLARx -44 [-50, -36] °C, AFA -31 [-38, -21] °C, p < 0.001) and lower nadir temperature (POLARx -60 [-65, -55] °C, AFA -48 [-54, -45] °C, p < 0.001). Procedure time (POLARx 80 [60, 105] min, AFA 62 [42, 80] min, p < 0.001), fluoroscopy time (POLARx 17 [13, 22] min, AFA 11 [7, 16] min, p < 0.001) and freeze cycles per patient (POLARx 5 [4, 6], AFA 4.5 [4, 5], p = 0.002) were higher in the POLARx group. Two cerebral ischemic events occurred in the POLARx group, two patients in each group had phrenic nerve injury.

CONCLUSION

Both systems enable effective isolation of pulmonary veins. The POLARx required longer procedure and fluoroscopy times. Larger, prospective and randomized studies are needed to assess long-term efficacy and safety of this technology.

Accuracy and acute efficacy of a novel occlusion tool to guide cryoballoon-based pulmonary vein isolation

Background

Cryoballoon (CB)-based pulmonary vein isolation (PVI) currently requires to verify occlusion of each pulmonary vein (PV) using fluoroscopy and dye injection.

Objective

The current study evaluated whether the novel CB-occlusion tool integrated into the wide-band dielectric imaging system KODEX-EPD reliably verifies occlusion of PV according to a novel dye-injection based algorithm.

Methods

Consecutive patients suffering from symptomatic atrial fibrillation (AF) underwent CB-based PVI using the KODEX-EPD and the novel occlusion-tool (group I). To confirm accurate display of the PVs, selective PV-angiography was performed in the first half of the patients of group I (group Ia) in addition to a three-dimensional left atrial (LA) map using a spiral mapping catheter (Achieve, SMC1, Medtronic, MN, USA). PV-angiographies were waived for the following patients (group Ib). Procedural duration and radiation exposure were compared to a control group of patients undergoing conventional CB-based PVI.

Results

CB-based PVI was successful in 50/50 patients of group I (mean age 63±11 years, 18 paroxysmal (36%)) and 25/25 patients of group II (66±10 years, 9 paroxysmal (60%)). Concordance of PV-occlusion as assessed by either PV-occlusion-angiography or KODEX-EPD, was documented in 237/272 (87%) occlusion-analyses among 198 PVs (95% for left superior PV, 93% for left inferior PV, 86% for right inferior PV and 77% for right superior PV).

In the final evaluation phase (group Ib) LA fluoroscopy times and dose area products were comparable to the conventional CB-ablation group (10.5±5 vs 8.8±4 minutes (p=0.23) and 403±425 vs 321±202 cGycm2 (p=0.44), whereas the amount of dye could be significantly reduced (group Ib: 31±10 ml vs group II: 70±20 ml, p&lt;0.0001).

Conclusion

The novel KODEX-EPD PV-occlusion tool allows for accurate PV-occlusion assessment in the majority of PVs and a high acute success rate. The system has the potential to reduce dye and radiation exposure. This should be evaluated in controlled clinical trials.

Funding Acknowledgement

Type of funding sources: None.

[Sexual abuse of care-dependent patients : Results of a nationwide cross-sectional study among general practitioners on responsibility and subjective confidence in dealing with suspected abuse]

Hintergrund

Gewalt gegen pflegebedürftige ältere Menschen ist häufig. Hausärzte/-ärztinnen können bei der Prävention von Gewalt eine Rolle spielen. Insbesondere sexualisierte Gewalt ist stark tabuisiert und wenig untersucht.

Ziel der Arbeit

Ziel dieser Arbeit ist es, die Einstellung von Hausärzten/-ärztinnen zu ihrer Verantwortung bei sexuellem Missbrauch pflegebedürftiger Patienten/Patientinnen zu untersuchen. Zugleich sollen die subjektive Sicherheit hinsichtlich des Vorgehens bei einem Missbrauchsverdacht sowie die Fortbildungsinteressen von Hausärzten/-ärztinnen zum Thema erhoben werden.

Material und Methoden

In einer Querschnittsstudie wurden 1700 Hausärzte/-ärztinnen in Deutschland zwischen September und November 2016 schriftlich befragt. Fragebogen von 302 Ärzten/Ärztinnen konnten ausgewertet werden.

Ergebnisse

Die Unsicherheit hinsichtlich des weiteren Vorgehens bei Verdacht auf sexuellen Missbrauch von pflegebedürftigen Patienten/Patientinnen ist groß. Nahezu alle Befragten sehen es als Teil der ärztlichen Verantwortung, bei sexuellem Missbrauch pflegebedürftiger Patienten/Patientinnen zu intervenieren. Hauptsächliches Fortbildungsinteresse besteht zur Differenzialdiagnose des sexuellen Missbrauchs sowie zum richtigen Vorgehen im Verdachtsfall.

Schlussfolgerung

Fortbildungen, insbesondere zu den Anzeichen sexueller Gewalt gegen Pflegebedürftige, können einen Beitrag leisten, die Handlungssicherheit von Hausärzten/-ärztinnen zu stärken und ihre Bereitschaft zur Prävention zu erhöhen.

Non-professional phagocytosis: a general feature of normal tissue cells

Non-professional phagocytosis by cancer cells has been described for decades. Recently, non-professional phagocytosis by normal tissue cells has been reported, which prompted us to take a closer look at this phenomenon. Non-professional phagocytosis was studied by staining cultured cells with live-cell staining dyes or by staining paraffin-embedded tissues by immunohistochemistry. Here, we report that each of 21 normal tissue cell lines from seven different organs was capable of phagocytosis, including ex vivo cell cultures examined before the 3rd passage as well as the primary and virus-transformed cell lines. We extended our analysis to an in vivo setting, and we found the occurrence of non-professional phagocytosis in healthy skin biopsies immediately after resection. Using dystrophin immunohistochemistry for membrane staining, human post-infarction myocardial tissue was assessed. We found prominent signs of non-professional phagocytosis at the transition zone of healthy and infarcted myocardia. Taken together, our findings suggest that non-professional phagocytosis is a general feature of normal tissue cells.

Interaction between somatostatin analogues and targeted therapies in neuroendocrine tumor cells

Somatostatin analogues (SSA) represent the standard of care for symptom control in patients with functional gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). In addition, SSA exert significant anti-proliferative effects in mid-gut and pancreatic NET (PanNET). In parallel, molecularly targeted therapies (MTT) have been shown to improve progression free survival (PFS) in patients with PanNET. However, due to either primary or acquired resistance to MTT, their impact on overall survival (OS) remains unclear. To date, various hypotheses exist to explain differences in patient responsiveness to SSA and MTT. However, data addressing one of the most pivotal questions, whether combining SSA with novel MTT will result in synergistic or additive efficacy compared to monotherapy, are lacking. The aim of this study is to characterize the interaction, optimal sequence and dosing of SSA-based and molecularly targeted therapies in PanNET. Somatostatin receptor subtypes 1–5 (SSTR) were evaluated in the neuroendocrine cell lines Bon1, QGP1 and Ins-1 via immunoblot and qRT-PCR. The impact of the SSA-analogue lanreotide alone or in combination with the MTT sunitinib, everolimus and regorafenib on intracellular signalling, hormone secretion and cell proliferation was determined in cell lysates and supernatants. In addition, synergistic effects of SSA and MTT in various sequential therapeutic approaches were investigated. SSTR were differently expressed in the examined neuroendocrine tumor cell lines. SSTR modulation via lanreotide moderately influenced proliferation, mainly via modulating AKT and ERK signalling, which was paralleled by decreased chromogranin A (CgA) expression and secretion. Interestingly, MTT treatment with regorafenib upregulated the expression of SSTR-2 and -5, while sunitinib and everolimus did not significantly alter SSTR expression. Cell viability was significantly reduced by all MTT, with regorafenib exerting the most significant effects. However, compared to the marked effects of MTT alone, synergistic effects of combined MTT and lanreotide treatment were only modest and time- and dose-dependent. SSTR are differentially expressed in various NEN cell lines. Their expression is influenced by MTT treatment. Various sequential or simultaneous combinations of lanreotide and MTT did not lead to significant synergistic effects.

Cytotoxic effect of Efavirenz in BxPC-3 pancreatic cancer cells is based on oxidative stress and is synergistic with ionizing radiation

The non-nucleoside reverse transcriptase inhibitor (NNRTI) Efavirenz is frequently used in human immunodeficiency virus treatment, but also efficient against cancer in mouse models. Its radiosensitizing effect makes it a promising drug for combination with radiotherapy. The efficacy of Efavirenz combined with irradiation was assessed with immunostaining of DNA-damage markers and colony formation assays in BxPC-3 pancreatic cancer cells. Gene expression and protein phosphorylation of the Efavirenz-sensitive BxPC-3 cells was compared to the resistant primary fibroblasts SBL-5. Oxidative stress, mitochondrial damage and cell death were studied with live-cell microscopy and flow cytometry. Combined Efavirenz and radiation significantly increased the number of γH2AX and phospho-ataxia telangiectasia mutated foci. Efavirenz and ionizing radiation had a synergistic effect using the clonogenic survival assay. Efavirenz selectively induced cell death in the BxPC-3 cells. The differing gene expression of cell cycle and apoptotic regulator genes in both cell cultures after Efavirenz treatment match with this selective effect against cancer cells. In the phosphoprotein array, an early phosphorylation of extracellular signal-related kinase 1/2 and p38 mitogen-activated protein kinase was notably detected in the cancer cells. The phosphorylation of AKT decreased in the cancer cells whereas it increased in the fibroblasts. Oxidative stress and mitochondrial membrane depolarization appeared in the cancer cells immediately after Efavirenz treatment, but not in the fibroblasts. Efavirenz has an anti-cancer effect against pancreatic cancer mainly by the induction of oxidative stress. The antitumor potential of Efavirenz and radiotherapy are additive.

Box Isolation of fibrotic areas: A substrate modification approach in atrial fibrillation patients

In the last years, atrial fibrosis was shown to be an independent predictor of procedural failure in patients with paroxysmal and persistent atrial fibrillation. Ablation strategies have been developed to improve the outcome of catheter ablation by targeting detected areas of fibrosis, based either on endocardial voltage mapping or cardiac magnetic resonance. Box isolation of fibrotic areas (BIFA) is a new and promising patient-tailored ablation strategy for atrial fibrillation patients targeting substantial fibrotic areas by circumferential isolation of left atrial fibrosis.

Global multielectrode contact mapping plus ablation with a single catheter: Preclinical and preliminary experience in humans with atrial fibrillation

INTRODUCTION

One question for the technological advancement of catheter ablation of atrial fibrillation (AF) is whether a creative new concept can combine and even improve the diagnostic mapping options of single-tip and basket catheters with the simplicity of the use of balloon catheters for ablation. Herein, we describe the first in-human experience with a single catheter offering such a complete solution.

METHODS AND RESULTS

A new catheter (Globe^® ) with a distal multielectrode array consisting of 16 ribs with 122 gold-plated electrodes was used. Each electrode can ablate, pace, and can measure tissue contact, temperature, current, and intracardiac electrograms. The Globe was deployed and removed without difficulty in all 3 patients. Complete pulmonary vein isolation (PVI) was achieved in all 12 veins. In 10 veins, PVI was achieved with a single placement in front of the respective vein ("single circle isolation"). In one subject, the device was repositioned due to the esophagus location. In the other subject, a single gap was observed after circumferential ablation of the right inferior PV. After precise gap identification, the device was adjusted slightly for improved contact at that region, and reablation resulted in immediate PVI.

CONCLUSIONS

PVI isolation could be performed with the new multielectrode array Globe in all 12 PVs offering the option for easy handling and fast "single-shot" PVI. Several continuously updated mapping types from 122 electrodes even in real time during ablation demonstrate the capability to go beyond PVI for voltage mapping plus substrate modification, and for rotor mapping plus rotor ablation.

Catheter ablation of atrial fibrillation with box isolation of fibrotic areas: Lessons on fibrosis distribution and extent, clinical characteristics, and their impact on long-term outcome

INTRODUCTION

The BIFA concept (box isolation of fibrotic areas) supplementing pulmonary vein isolation (PVI) was implemented in atrial fibrillation (AF) patients with fibrotic atrial cardiomyopathy (FACM) to improve catheter ablation outcomes.

METHODS AND RESULTS

Ninety-two patients with FACM underwent PVI + BIFA. We investigated patient characteristics (58 persistent/34 paroxysmal, 68 ± 8 years, LA 44 ± 7 mm, CHA₂ DS₂ -VASc 2.6 ± 1.3, FACM I: 15.2%, II: 53.3%, III: 26.1%, IV: 5.4%), periprocedural data concerning fibrosis extent/distribution, and their impact on outcome. Based on severe fibrosis areas (SFAs) of 13.5 ± 13.9 cm² detected by voltage mapping, 1.4 ± 0.5 boxes (n = 1-3, 2.2-35.3 cm² ) were applied in the left atrium. With higher grade FACM, SFAs increased and maximum voltage decreased (I/IV: 6.29/3.18 mV). Anterior (ant.) SFAs were found to be more common and larger than posterior (post.) SFAs (58.3% vs. 42.6%, ant. 8.0 ± 8.0 vs. post. 4.7 ± 6.8 cm² ). In 40 of 92 (43%) patients, both atrial walls were affected with rare cases of solely post. fibrosis (6 of 92, 6.6%). Women (39 of 92, 42%) showed FACM III+IV more often than men (P = 0.022) and can still present paroxysmal while persistent males are more likely to have FACM I-II. Single and multiple procedure (1.2/patient) success was 69% and 83% after 16 ± 8 months with an unfavorable impact of large SFA size, both-sided fibrosis and reduced maximum voltage, independently of patient characteristics and AF type.

CONCLUSION

FACM patients are a challenging AF subgroup for catheter ablation. Women seem to show FACM III+IV more often than men. The distribution of left atrial fibrosis is variable but more pronounced anteriorly. Atrial disease is characterized by SFA size but also maximum voltage reduction, both with implications on ablation outcome. Using BIFA, success rates of patients without fibrosis can be approached but are limited in FACM III+IV.

Global health education in Germany: an analysis of current capacity, needs and barriers

BACKGROUND

In times of increasing global challenges to health, it is crucial to create a workforce capable of tackling these complex issues. Even though a lack of GHE in Germany is perceived by multiple stakeholders, no systematic analysis of the current landscape exists. The aim of this study is to provide an analysis of the global health education (GHE) capacity in Germany as well as to identify gaps, barriers and future strategies.

METHODS

An online search in combination with information provided by student representatives, course coordinators and lecturers was used to create an overview of the current GHE landscape in Germany. Additionally, a semi-structured questionnaire was sent to GHE educators and students engaged in global health (GH) to assess the capacity of German GHE, its barriers and suggested strategies for the future.

RESULTS

A total of 33 GHE activities were identified at 18 German universities. Even though medical schools are the main provider of GHE (42%), out of 38 medical schools, only 13 (34%) offer any kind of GHE. Modules offered for students of other health-related professions constitute 27% of all activities. Most survey respondents (92%, n = 48) consider current GHE activities in Germany insufficient. Suggested formats were GHE as part of medical curricula (82%, n = 45) and dual degree MD/MPH or PhD programs. Most important barriers mentioned were low priority of GH at faculties and academic management levels (n = 41, 75%) as well as lack of necessary institutional structures (n = 33, 60%).

CONCLUSIONS

Despite some innovative academic approaches, there is clearly a need for more systematic GHE in Germany. GHE educators and students can take an important role advocating for more awareness at university management level and suggesting ways to institutionalize GHE to overcome barriers. This study provides key evidence, relevant perceptions and suggestions to strengthen GHE in Germany.