Aims
Pulmonary vein isolation (PVI) using radiofrequency ablation (RFA) in patients with paroxysmal atrial fibrillation (PAF) is effective but hampered by pulmonary vein reconnection due to insufficient ablation lesions. High-power delivery over a short period of time (HPSD) in RFA is stated to create more efficient lesions. The aim of this study was to compare intraprocedural safety and outcome of HPSD ablation to conventional power settings in patients undergoing PVI for PAF.
Methods and results
We included 197 patients with PAF that were scheduled for PVI. An ablation protocol with 70 W and a duration cut-off of 7 s at the anterior left atrium (LA) and 5 s at the posterior LA (HPSD group; n = 97) was compared to a conventional power protocol with 30–40 W for 20–40 s (standard group; n = 100) in terms of periprocedural complications and a 1-year outcome. The HPSD group showed significantly less arrhythmia recurrence during 1-year follow-up with 83.1% of patients free from atrial fibrillation compared to 65.1% in the standard group (P < 0.013). No pericardial tamponade, periprocedural thromboembolic complications, or atrio-oesophageal fistula occurred in either group. Mean radiofrequency time (12.4 ± 3.4 min vs. 35.6 ± 12.1 min) and procedural time (89.5 ± 23.9 min vs. 111.15 ± 27.9 min) were significantly shorter in the HPSD group compared to the standard group (both P < 0.001).
Conclusion
High-power short-duration ablation demonstrated a comparable safety profile to conventional ablation. High-power short-duration ablation using 70 W for 5–7 s leads to significantly less arrhythmia recurrences after 1 year. Radiofrequency and procedural time were significantly shortened.
Colchicine demonstrated superior efficacy versus usual care for prevention of atrial fibrillation after cardiac surgery. Moreover, colchicine treatment was associated with shorter hospital stays. These benefits outweigh increased risk of adverse drug-related effects; although further work is needed to minimize gastrointestinal effects.
Therapy with dual-chamber settings for ICD discrimination combined with algorithms for minimizing ventricular pacing was associated with reduced risk for inappropriate shock compared with single-chamber settings, without increases in mortality and morbidity. (Optimal Anti-Tachycardia Therapy in Implantable Cardioverter-Defibrillator [ICD] Patients Without Pacing Indications [OPTION]; NCT00729703).
In patients with atrial fibrillation, oral anticoagulation with oral thrombin inhibitors (OTIs), in contrast to vitamin K antagonists (VKAs), associates with a modest increase in acute coronary syndromes (ACSs). Whether this observation is causatively linked to OTI treatment and, if so, whether OTI action is the result of a lower antithrombotic efficacy of OTI compared to VKA or reflects a yet undefined prothrombotic activity of OTI remain unclear. We analyzed platelet function in patients receiving OTI or dose-adapted VKA under static and flow conditions. In vivo, we studied arterial thrombosis in OTI-, VKA-, and vehicle-treated mice using carotid ligation and wire injury models. Further, we examined thrombus formation on human atherosclerotic plaque homogenates under arterial shear to address the relevance to human pathology. Under static conditions, aggregation in the presence of ristocetin was increased in OTI-treated blood, whereas platelet reactivity and aggregation to other agonists were only marginally affected. Under flow conditions, firm platelet adhesion and thrombus formation on von Willebrand factor, collagen, and human atherosclerotic plaque were increased in the presence of OTI in comparison to VKA. OTI treatment was associated with increased thrombus formation in injured carotid arteries of mice. Inhibition or ablation of GPIbα-thrombin interactions abolished the effect of OTI on thrombus formation, suggesting a mechanistic role of the platelet receptor GPIbα and its thrombin-binding site. The effect of OTI was also abrogated in the presence of aspirin. In summary, OTI treatment has prothrombotic activity that might contribute to the increase in ACS observed clinically in patients.
BackgroundThe placement of an implantable cardioverter defibrillator (ICD) has become routine practice to protect high risk patients from sudden cardiac death. However, implantation-related myocardial micro-damage and its relation to different implantation strategies are poorly characterized.MethodsA total of 194 ICD recipients (64±12 years, 83% male, 95% primary prevention of sudden cardiac death, 35% cardiac resynchronization therapy) were randomly assigned to one of three implantation strategies: (1) ICD implantation without any defibrillation threshold (DFT) testing, (2) estimation of the DFT without arrhythmia induction (modified “upper limit of vulnerability (ULV) testing”) or (3) traditional safety margin testing including ventricular arrhythmia induction. High-sensitive Troponin T (hsTnT) levels were determined prior to the implantation and 6 hours after.ResultsAll three groups showed a postoperative increase of hsTnT. The mean delta was 0.031±0.032 ng/ml for patients without DFT testing, 0.080±0.067 ng/ml for the modified ULV-testing and 0.064±0.056 ng/ml for patients with traditional safety margin testing. Delta hsTnT was significantly larger in both of the groups with intraoperative ICD testing compared to the non-testing strategy (p≤0.001 each). There was no statistical difference in delta hsTnT between the two groups with intraoperative ICD testing (p = 0.179).ConclusionHigh-sensitive Troponin T release during ICD implantation is significantly higher in patients with intraoperative ICD testing using shock applications compared to those without testing. Shock applications, with or without arrhythmia induction, did not result in a significantly different delta hsTnT. Hence, the ICD shock itself and not ventricular fibrillation seems to cause myocardial micro-damage.Trial RegistrationClinicalTrials.gov NCT01230086
Three-dimensional-augmented fluoroscopy is feasible, safe, and easy to apply as guidance for transseptal puncture and demonstrates a high level of accuracy.
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