Ablation of Stable VTs Versus Substrate Ablation in Ischemic Cardiomyopathy the VISTA Randomized Multicenter Trial

Background Catheter ablation reduces ventricular tachycardia (VT) recurrence and implantable cardioverter defibrillator shocks in patients with VT and ischemic cardiomyopathy. The most effective catheter ablation technique is unknown. Objectives This study determined rates of VT recurrence in patients undergoing ablation limited to clinical VT along with mappable VTs ("clinical ablation") versus substrate-based ablation. Methods Subjects with ischemic cardiomyopathy and hemodynamically tolerated VT were randomized to clinical ablation (n = 60) versus substrate-based ablation that targeted all "abnormal" electrograms in the scar (n = 58). Primary endpoint was recurrence of VT. Secondary endpoints included periprocedural complications, 12-month mortality, and rehospitalizations. Results At 12-month follow-up, 9 (15.5%) and 29 (48.3%) patients had VT recurrence in substrate-based and clinical VT ablation groups, respectively (log-rank p < 0.001). More patients undergoing clinical VT ablation (58%) were on antiarrhythmic drugs after ablation versus substrate-based ablation (12%; p < 0.001). Seven (12%) patients with substrate ablation and 19 (32%) with clinical ablation required rehospitalization (p = 0.014). Overall 12-month mortality was 11.9%; 8.6% in substrate ablation and 15.0% in clinical ablation groups, respectively (log-rank p = 0.21). Combined incidence of rehospitalization and mortality was significantly lower with substrate ablation (p = 0.003). Periprocedural complications were similar in both groups (p = 0.61). Conclusions An extensive substrate-based ablation approach is superior to ablation targeting only clinical and stable VTs in patients with ischemic cardiomyopathy presenting with tolerated VT

Status of passive environmental dosimetry in Europe.

EURADOS Working Group 3 (WG3) aims at providing information about the correct measurement of the ambient dose equivalent (rate) in the environment and has a specific subgroup (WG3-SG2) that focuses on passive environmental dosimetry. One of the initial tasks of the subgroup was to gain an overview of passive dosimetry practices in Europe. On the basis of a survey carried out by this subgroup in 2013/2014, information on the state-of-the-art was gained, several conclusions were drawn and some open questions have been identified, e.g. the harmonization in the terminology, uncertainty assessment procedures and corrections of measured values by passive dosemeters due to transport and climate. (C) 2017 Elsevier Ltd. All rights reserved

EURADOS intercomparison of passive<em> H*</em>(10) area dosemeters 2014.

Under the umbrella of the European Radiation Dosimetry Group (EURADOS), different working groups have responded to the requests of monitoring services in Europe for independent tests of dosimetry systems for harmonization and quality assurance. After having performed regular intercomparisons of personal dosemeters, EURADOS Working Group 3, &quot;Environmental Dosimetry&quot;, performed the first EURADOS intercomparison for passive ambient dose equivalent, abbreviated H*(10), area dosemeters used for environmental monitoring in 2014 (IC2014env). Such dosimetry systems are generally used to monitor nuclear installations, besides other applications. The results of this intercomparison with a total of more than 500 dosemeters help to better understand influence parameters and the possible accuracy of typical dosimetric measurements using passive dosemeters. (C) 2017 Elsevier Ltd. All rights reserved

Novel single-nucleotide polymorphisms predict the risk of recurrence in patients with atrial fibrillation undergoing catheter ablation

background: Genome-wide association studies have identified several atrial fibrillation (AF)-associated single-nucleotide polymorphisms (SNPs). This study tested the hypothesis that selected SNPs are linked with AF recurrence following catheter ablation. Methods: Four hundred AF patients (67% male, 62\ub112 year, left atrial size 45.3\ub17 mm, 64% non-paroxysmal) undergoing catheter ablation were prospectively enrolled. DNA extraction and genotyping for AF-associated SNPs, rs6843082 and rs1448817 were performed from collected blood samples using Qiagen QiaAMP kit and TaqMan assay respectively. Three hundred seventy-two DNA samples were available for genotyping. Multivariate logistic regression analysis (adjusted covariates: age, gender, non-paroxysmal AF, hypertension and diabetes) was used for assessing predictive role of individual SNP with AF recurrence and false discovery rate (FDR) was computed for the candidate SNPs to address multiple testing. Patients were followed up for 1 year. Recurrence was defined as any episode of AF/ Aflutter/ AT lasting >30 seconds and was acquired by event-recorder for the first 5 months followed by series of 7-day Holter recordings at 3 months interval. results: Of 371, 207 patients (55.8%) experienced recurrence after the first procedure. In the overall AF population, rs6843082 showed significant inverse association (OR 0.536 [95%CI 0.338-0.849], p=0.008) with arrhythmia recurrence whereas rs1448817 predicted increased risk of post-ablation recurrence (OR 1.761 [95%CI 1.112-2.788], p=0.016). FDR was controlled at 1.58% for both SNPs to adjust for multiple testing. Conclusion: Our study identified two novel SNPs, rs6843082 and rs1448817 on chromosome 4q25 that are associated with the risk for arrhythmia recurrence after catheter ablation for AF; while rs6843082 confers lower risk; rs1448817 predicts increased chance of recurrence. This finding provides possible evidence of differential influence of the two SNPs on the nearby functional genes in modulating ablation outcome in atrial fibrillation patients

Novel association of polymorphic genetic variants with predictors of outcome of catheter ablation in atrial fibrillation: new directions from a prospective study (DECAF)

background: Non-pulmonary vein (non-PV) triggers and left atrial (LA) scars perpetuate atrial fibrillation (AF) and limit the success rate of catheter ablation. As these risk factors manifest in some AF patients and not in all, understanding their genetic basis will offer insight into the inter-individual differences in the clinical presentation and therapeutic approaches of this complex arrhythmia. We examined the association of selected single nucleotide polymorphisms (SNPs) with scar and non-PV triggers. Methods: Four hundred AF patients (67% male, 62\ub112 year, LA size 45.3\ub17 mm, 64% non-paroxysmal) undergoing catheter ablation were prospectively enrolled at our center. DNA extraction and genotyping for 16 AF-related SNPS from blood samples were performed using Qiagen QiaAMP kit and TaqMan assay respectively. Three hundred seventy two DNA samples were available for genotyping. Multivariate logistic regression analysis (adjusted covariates: age, gender, LA size, hypertension and diabetes) was used for assessing predictive role of individual SNP; and logistic kernel-machine approach was applied to test the cumulative effect of multiple SNPs as a group with non-PV triggers and LA scar. results: SNPs, rs6599230, rs6843082, were inversely associated (OR 0.68, p= 0.04; and 0.62, p=0.01 respectively) whereas rs1448817 (OR 1.74, p= 0.04), and rs7193343 (OR 1.66, p= 0.02) predicted higher risk of non-PV triggers. Genotypes for rs6599230 and rs6843082 conferred 51% reduction in the odds for non-PV triggers (combined OR 0.49, p=0.019), while rs1448817 and rs7193343 demonstrated a combined OR of 1.93, p=0.025. For LA scar, inverse association was observed with rs1448817 (OR 0.29, p=0.006), rs17042171 (OR 0.27, p=0.032), rs3807989 (OR 0.54, p=0.017), and rs6843082 (OR 0.56, p=0.009). Two SNPs were associated with increased scar risk; rs17375901 (OR 3.68, p=0.03), and rs7193343 (OR 1.74, p=0.037). Conclusion: We identified novel genetic markers that influence the risk for non-PV triggers and LA scar in atrial fibrillation patients. Our results suggest that in patients carrying those risk variants, operators may need to adopt individualized ablation strategies to maximize procedural success