Background: In the past decade, catheter ablation has become an established therapy for symptomatic atrial fibrillation ( AF ). Until very recently, few data have been available to guide the clinical community on the outcomes of AF ablation at ≥3 years of follow‐up. We aimed to systematically review the medical literature to evaluate the long‐term outcomes of AF ablation. Methods and Results: A structured electronic database search (PubMed, Embase, Web of Science, Cochrane) of the scientific literature was performed for studies describing outcomes at ≥3 years after AF ablation, with a mean follow‐up of ≥24 months after the index procedure. The following data were extracted: (1) single‐procedure success, (2) multiple‐procedure success, and (3) requirement for repeat procedures. Data were extracted from 19 studies, including 6167 patients undergoing AF ablation. Single‐procedure freedom from atrial arrhythmia at long‐term follow‐up was 53.1% (95% CI 46.2% to 60.0%) overall, 54.1% (95% CI 44.4% to 63.4%) in paroxysmal AF , and 41.8% (95% CI 25.2% to 60.5%) in nonparoxysmal AF . Substantial heterogeneity (I ² >50%) was noted for single‐procedure outcomes. With multiple procedures, the long‐term success rate was 79.8% (95% CI 75.0% to 83.8%) overall, with significant heterogeneity (I ² >50%).The average number of procedures per patient was 1.51 (95% CI 1.36 to 1.67). Conclusions: Catheter ablation is an effective and durable long‐term therapeutic strategy for some AF patients. Although significant heterogeneity is seen with single procedures, long‐term freedom from atrial arrhythmia can be achieved in some patients, but multiple procedures may be required.

OBJECTIVE: To identify sensitive periods of postnatal growth for preterm infants relative to neurodevelopment at 18 months9 corrected age. PATIENTS AND METHODS: We studied 613 infants born at <33 weeks9 gestation who participated in the DHA for Improvement of Neurodevelopmental Outcome trial. We calculated linear slopes of growth in weight, length, BMI, and head circumference from 1 week of age to term (40 weeks9 postmenstrual age), term to 4 months, and 4 to 12 months, and we estimated their associations with Bayley Scales of Infant Development, 2nd Edition, Mental (MDI) and Psychomotor (PDI) Development Indexes in linear regression. RESULTS: The median gestational age was 30 (range: 2–33) weeks. Mean ± SD MDI was 94 ± 16, and PDI was 93 ± 16. From 1 week to term, greater weight gain (2.4 MDI points per z score [95% confidence interval (CI): 0.8–3.9]; 2.7 PDI points [95% CI: 1.2–.2]), BMI gain (1.7 MDI points [95% CI: 0.4–3.1]; 2.5 PDI points [95% CI: 1.2–3.9]), and head growth (1.4 MDI points [95% CI: −0.0–2.8]; 2.5 PDI points [95% CI: 1.2–3.9]) were associated with higher scores. From term to 4 months, greater weight gain (1.7 points [95% CI: 0.2–3.1]) and linear growth (2.0 points [95% CI: 0.7–3.2]), but not BMI gain, were associated with higher PDI. From 4 to 12 months, none of the growth measures was associated with MDI or PDI score. CONCLUSIONS: In preterm infants, greater weight and BMI gain to term were associated with better neurodevelopmental outcomes. After term, greater weight gain was also associated with better outcomes, but increasing weight out of proportion to length did not confer additional benefit.

Background—: Atrial fibrillation ablation is an established therapy; however, limited data are available on associated complications. This systematic review determines the incidence and potential predictors of acute complications. Methods and Results—: Electronic searches were conducted in MEDLINE and EMBASE for English scientific literature up to the 18th June 2012. A total of 2065 references were retrieved and evaluated for relevance. Reference lists of retrieved studies and review articles were examined to ensure all relevant studies were included. Data were extracted from 192 studies, total of 83 236 patients. The incidence of periprocedural complications for catheter ablation of atrial fibrillation was 2.9% (95% confidence interval, 2.6–3.2). There was a significant decrease in the acute complication rate in 2007 to 2012 compared with 2000 to 2006 (2.6% versus 4.0%; P =0.003). The complication rates reported were higher in prospective studies compared with those that retrospectively described complications (3.5% versus 2.7%; P =0.03). There were no significant associations among procedure duration, ablation time or ablation strategy, and acute complication rate. Conclusions—: Catheter ablation of atrial fibrillation has a low incidence of periprocedural complications. The acute complication rate has decreased significantly in recent years. This may reflect improved catheter technology and experience. The use of different strategies across centers worldwide seems to be safe with no established relationship between procedural variables and complication rate.

The use of multiple imputation has increased markedly in recent years, and journal reviewers may expect to see multiple imputation used to handle missing data. However in randomized trials, where treatment group is always observed and independent of baseline covariates, other approaches may be preferable. Using data simulation we evaluated multiple imputation, performed both overall and separately by randomized group, across a range of commonly encountered scenarios. We considered both missing outcome and missing baseline data, with missing outcome data induced under missing at random mechanisms. Provided the analysis model was correctly specified, multiple imputation produced unbiased treatment effect estimates, but alternative unbiased approaches were often more efficient. When the analysis model overlooked an interaction effect involving randomized group, multiple imputation produced biased estimates of the average treatment effect when applied to missing outcome data, unless imputation was performed separately by randomized group. Based on these results, we conclude that multiple imputation should not be seen as the only acceptable way to handle missing data in randomized trials. In settings where multiple imputation is adopted, we recommend that imputation is carried out separately by randomized group.