A worldwide survey on incidence, management and prognosis of oesophageal fistula formation following atrial fibrillation catheter ablation: The POTTER-AF study.

AIMS Oesophageal fistula represents a rare but dreadful complication of atrial fibrillation catheter ablation. Data on its incidence, management and outcome are sparse. METHODS AND RESULTS This international multicenter registry investigates the characteristics of oesophageal fistulae after treatment of atrial fibrillation by catheter ablation. A total of 553,729 catheter ablation procedures (radiofrequency: 62.9%, cryoballoon: 36.2%, other modalities: 0.9%) were performed at 214 centers in 35 countries. In 78 centers 138 patients (0.025%, radiofrequency: 0.038%, cryoballoon: 0.0015% (p<0.0001)) were diagnosed with an oesophageal fistula. Periprocedural data were available for 118 patients (85.5%). Following catheter ablation, the median time to symptoms and the median time to diagnosis were 18 (7.75, 25; range: 0-60) days and 21 (15, 29.5; range: 2-63) days, respectively. The median time from symptom onset to oesophageal fistula diagnosis was 3 (1, 9; range: 0-42) days. The most common initial symptom was fever (59.3%). The diagnosis was established by chest computed tomography in 80.2% of patients. Oesophageal surgery was performed in 47.4% and direct endoscopic treatment in 19.8%, and conservative treatment in 32.8% of patients. The overall mortality was 65.8%. Mortality following surgical (51.9%) or endoscopic treatment (56.5%) was significantly lower as compared to conservative management (89.5%) (odds ratio 7.463 (2.414, 23.072) p<0.001). CONCLUSIONS Oesophageal fistula after catheter ablation of atrial fibrillation is rare and occurs mostly with the use of radiofrequency energy rather than cryoenergy. Mortality without surgical or endoscopic intervention is exceedingly high

Einfluss neurotropher und kleinmolekularer Substanzen auf das Wachstum transgerminal konvertierter mesenchymaler Stammzellen

Background: Mesenchymal stem cells (MSC) could be a promising source for the therapy of neurodegenerative diseases. Various protocols have been investigated for the transgerminal conversion of MSC into neuronal stem cell-like cells (mNSC). This study evaluated the effect on proliferation and apoptosis of protocol variation by adding substances playing a role in neurogenesis. Methods: Proliferation was measured by cell cycle analysis using flow cytometry, immunostaining with BrdU, and cell counting. Apoptosis was evaluated by Annexin/Propidiumiodid (PI) staining. For some factors, CD 318 expression was analysed. Morphology was observed during the conversion process. Results: Proliferation of MSC was higher (26 %) compared to mNSC growing under adherent conditions (12 %) or growing in suspension (8 %). The difference between adherent and suspension culture may be explained by anoikis, that is cell death by loosing contact to the extracellular matrix. The growth factors brain derived neurotrohpic factor, fibroblast growth factor 8 and sonic hedgehog showed no effect on proliferation or apoptosis. Leukaemia inhibitory factor (LIF) increased cell death as revealed by annexin/PI staining. Valproat acid changed the morphology of the cells (the cell body became more flat and the cell branches became longer and more numerous). The histon-deacetylase inhibitor Trichostatin A (TSA) showed an increase of S and G2/M phases, but decreased cell numbers. This effect could have been induced by a cell cycle arrest. TSA and LIF increased the CD318 expression. Retinoic acid caused a high apoptosis rate in the used concentration. Conclusion: None of the substances used in this study showed a significant improvement of proliferation or a decrease of apoptosis. Further studies should evaluate how the substances work on the reprogramming of MSC, especially with regard to the recently found transcription factors responsible for the pluripotency of stem cells

Automated three-dimensional activation versus conventional mapping for catheter ablation of atrial tachycardia – A prospective randomized trial

Background: The automated NavX Ensite Precision latency-map (LM) algorithm aims to identify atrial tachycardia (AT) mechanisms. However, data on a direct comparison of this algorithm with conventional mapping are scarce. Methods: Patients scheduled for AT ablation were randomized to mapping with the LM- algorithm (LM group) or to conventional mapping (conventional only group: ConvO), using entrainment and local activation mapping techniques. Several outcomes were exploratively analyzed. Primary endpoint was intraprocedural AT Termination. If AT termination with only automated 3D-Mapping failed, additional conventional methods were applied (conversion). Results: A total of 63 patients (mean 67 years, 34 % female) were enrolled. In the LM group (n = 31), the correct AT mechanism was identified in 14 patients (45 %) using the algorithm alone compared to 30 patients (94 %) with conventional methods. Time to termination of the first AT was not different between groups (LM group 34 ± 20 vs. ConvO 43.1 ± 28.3 min; p = 0.2). However, when AT termination did not occur with LM algorithm, time to termination prolonged significantly (65 ± 35 min; p = 0.01). After applying conventional methods (conversion), procedural termination rates did not differ between LM group (90 %) vs. ConvO (94 %) (p = 0.3). During a follow-up time of 20 ± 9 months, no differences were observed in clinical outcomes. Conclusion: In this small prospective, randomized study, the use of the LM algorithm alone may lead to AT termination, but less accurate than conventional methods