Correction to: Role of complement and potential of complement inhibitors in myasthenia gravis and neuromyelitis optica spectrum disorders: a brief review

Journal of Neurology - The original version of this article unfortunately contained a mistake. Fifth sentence of the fourth paragraph in the section “Non-nAChR autoantibody targets in...     

Improved outcomes and complications of atrial fibrillation catheter ablation over time: learning curve, techniques, and methodology

Introduction and objectives

The outcomes of atrial fibrillation ablation procedures vary widely between different centers. Our objective was to analyze the results and complications of this procedure in our center and identify factors predicting the efficacy and safety of atrial fibrillation ablation.

Methods

In total, 726 atrial fibrillation ablation procedures were performed in our center between 2002 and 2009. Beginning in January 2008, a protocol for anticoagulation and conscious sedation was systematically applied. Outcomes and complications could therefore be compared in 2 well-differentiated groups: group A included 419 procedures performed prior to 2008 and group B included 307 procedures completed after 2008 using the new protocol.

Results

During an average follow-up of 8.7 months, 60.9% of patients were arrhythmia-free after one or repeat procedures. After only 1 procedure, the success rate was 41% and significantly higher in group B (51.6% vs 35.2% in group A; P=.001). There were 31 major complications (4.2%), 26 in group A (6.2%) and 5 in group B (1.6%) (P=.002). The implementation of the new protocol was an independent predictor of the absence of complications (odds ratio=0.406; 95% confidence interval, 0.214-0.769; P<.006).

Conclusions

Systematic application of an anticoagulation and conscious sedation protocol is associated with improved results and fewer complications of atrial fibrillation ablation. Factors not evaluated in the present study, such as operator experience and ongoing improvements in atrial fibrillation ablation technology, could have influenced these findings.Full English text available from:www.revespcardiol.org     

Incidence of Pulmonary Vein Stenosis in Patients Submitted to Atrial Fibrillation Ablation: A Comparison of the Selective Segmental Ostial Ablation vs the Circumferential Pulmonary Veins Ablation

Introduction: Pulmonary vein (PV) stenosis is an important complication of the AF ablation and could be underestimated if their assessment is not systematically done. Selective Segmental Ostial Ablation (SSOA) and Circunferential Pulmonary Veins Ablation (CPVA) have demonstrated efficacy in atrial fibrillation (AF) treatment. In this study the real incidence of PV stenosis in patients (pts) submitted to both SSOA and CPVA was compared. Methods: Those pts with focal activity and normal left atrial size were submitted to SSOA, remaining pts were submitted to CPVA to treat refractory, symptomatic AF. Contrast enhanced magnetic resonance angiography (MRA) was routinely performed in all patients 4 months after the procedure. Results: A series of 73 consecutive patients (mean age of 51 ± 11 years; 75% male) were included. SSOA was performed in 32 patients, and the remaining 41 patients underwent to CPVA, obtaining similar efficacy rates (72% vs 76% arrythmia free probability at 12 months; log rank test p = NS). Six patients had a significant PV stenosis, all in SSOA group none in CPVA group (18.8% vs 0%; p = 0.005). All patients were asymptomatic and the stenosis was detected in routine MRA. No predictors of stenosis has been identified analysing patient procedure characteristics. Conclusion: PV stenosis is a potential complication of SSOA not seen in CPVA. The study confirms than MRA is useful for identifying patients with asymptomatic PV stenosis. Santiago Nava, A. Berruezo and A. Scalise were supported in part by a Grant from the Fundació Clínic per la Recerca Biomèdica.     

Neuromyelitis optica: changing concepts

Neuromyelitis optica (NMO; Devic's disease) and the NMO spectrum disorders are idiopathic inflammatory demyelinating disorders that affect the central nervous system and have a predilection for optic nerves and spinal cord. The identification of NMO-IgG as a disease-specific marker and aquaporin 4 as the target antigen has renewed interest in NMO. Based on current data, we suspect that autoantibodies arising from peripheral B cells bind to aquaporin 4 expressed on astrocyte foot processes on the abluminal surface of microvessels, activate complement and initiate inflammatory demyelination and necrosis. The development of animal models and further analysis of the association of NMO-IgG with disease severity and treatment response will elucidate the pathobiology of NMO.     

Association of IL2RA polymorphisms with susceptibility to multiple sclerosis is not explained by missense mutations in IL2RA

Genome-wide association studies have identified an association between two intronic single nucleotide polymorphisms (SNPs), rs12722489 and rs2104286, in the interleukin-2 receptor alpha-chain gene (IL2RA) and susceptibility to multiple sclerosis (MS). We studied these SNPs in association with susceptibility to and severity of MS in a population-based cohort of 220 patients from Olmsted County, Minnesota, compared with 442 matched controls. We sequenced the exons, splice sites and 5' and 3' untranslated regions in 27 randomly selected MS patients (powered for allele frequency≥0.04) to search for mutations. No novel missense mutation was identified. Two patients (7.5%) had an exon 2 SNP (rs4308625) and two patients had an exon 4 SNP (rs2228149), both synonymous.     

Intractable vomiting as the initial presentation of neuromyelitis optica

We report 12 aquaporin-4 antibody-positive patients (12% of seropositive Mayo Clinic patients identified since 2005) whose initial presenting symptom of neuromyelitis optica was intractable vomiting. The initial evaluation in 75% was gastroenterologic. Vomiting lasted a median of 4 weeks (range, 2 days-80 weeks). Optic neuritis or transverse myelitis developed after vomiting onset in 11 patients (median interval, 11 weeks; range, 1-156). At last evaluation (median, 48 months after vomiting onset), 7 patients fulfilled neuromyelitis optica diagnostic criteria. Our clinical, pathologic and neuroimaging observations suggest the aquaporin-4-rich area postrema may be a first point of attack in neuromyelitis optica.     

Left atrial contractility is preserved after successful circumferential pulmonary vein ablation in patients with atrial fibrillation

Introduction: Circumferential pulmonary vein ablation (CPVA) for atrial fibrillation (AF) consists of creating extensive lesions in the left atrium (LA). The aim of the study was to evaluate changes in LA contractility after ablation and their relationship with procedure outcome.
Methods and Results: A series of 90 consecutive patients underwent cardiac magnetic resonance imaging (MRI) before and 4–6 months after CPVA. Only patients in sinus rhythm during both imaging acquisitions were included in the study to measure LA end-diastolic (LAmax) and LA end-systolic (LAmin) volumes. Fifty-five patients were finally analyzed (41 men, 52 ± 11 years, 74% paroxysmal AF). During a mean follow-up of 12 ± 7 months and after 1.2 ± 0.3 ablation procedures, 38 patients (69%) were arrhythmia-free (group I), and the remaining 17 patients had recurrences (group II). There was a significant decrease in mean LAmax volume in both groups, whereas mean LAmin volume only decreased in group I. Mean LA ejection fraction (EF) was preserved after CPVA in group I (40 ± 11% vs 38 ± 10%; P = 0.27) but decreased in patients with arrhythmia recurrences (37 ± 10% vs 27 ± 10%; P < 0.001). In fact, LA EF remained stable or increased in 68% of patients without arrhythmia recurrences.
Conclusions: LAmax volume reduction following CPVA occurs regardless of the clinical efficacy of the procedure, whereas mean LAmin volume only decreased in patients without recurrences. LA EF was preserved or even increased in most patients with successful CPVA.