Background Common single nucleotide polymorphisms (SNPs) at chromosome 4q25 (rs2200733, rs10033464) are associated with both lone and typical AF. Risk alleles at 4q25 have recently been shown to predict recurrence of AF after ablation in a population of predominately lone AF, but lone AF represents only 5–30% of AF cases. Objective To test the hypothesis that 4q25 AF risk alleles can predict response to AF ablation in the majority of AF cases. Methods Patients enrolled in the Vanderbilt AF Registry underwent 378 catheter-based AF ablations (median age 60 years, 71% male, 89% typical AF) between 2004 and 2011. The primary endpoint was time to recurrence of any non-sinus atrial tachyarrhythmia (atrial tachycardia, atrial flutter, or AF; [AT/AF]). Results Two-hundred AT/AF recurrences (53%) were observed. In multivariable analysis, the rs2200733 risk allele predicted a 24% shorter recurrence-free time (survival time ratio 0.76 95% confidence interval [CI] 0.6–0.95, P=0.016) compared with wild-type. The heterozygous haplotype demonstrated a 21% shorter recurrence-free time (survival time ratio = 0.79, 95% CI 0.62–0.99) and the homozygous risk allele carriers a 39% shorter recurrence-free time (survival time ratio = 0.61, 95% CI 0.37–1.0) (P=0.037). Conclusion Risk alleles at the 4q25 loci predict impaired clinical response to AF ablation in a population of predominately typical AF patients. Our findings suggest the rs2200733 polymorphism may hold promise as an as an objectively measured patient characteristic that can used as a clinical tool for selection of patients for AF ablation.

Many HF patients were poor at interpreting and managing their symptoms. These results suggest a subgroup of patients to target for intervention.

Obese patients with atrial fibrillation (AF) are frequently managed with AF ablation. We sought to examine whether there exists a body mass index (BMI) threshold beyond which odds of experiencing a complication from AF ablation increase. All patients enrolled in the Vanderbilt AF Registry who underwent catheter-based AF ablation from May 1999 to February 2012 were included. Major complications were recorded. Morbid obesity was defined as BMI >40 kg/m2, and BMI as a continuous variable was examined in multivariable analysis. Thirty-five complications (6.8%) occurred in 512 ablations. Morbidly obese patients experienced a higher rate of complications (6/42, 14.3%) than non-morbidly obese (29/470, 6.2%) (P=0.046). Using a discrete BMI cut-off, the odds of complications increased 3.1-fold in those with morbid obesity (odds ratio [OR] 3.1, 95% Confidence Interval [CI] 1.1–8.4, P=0.03) and 2.1-fold by female gender (OR 2.1, 95% CI 1.04–4.38, P=0.04). With BMI as a continuous variable, the odds of complications increased by 5% per 1 unit increase in BMI (OR 1.05, 95% CI 1.0–1.11, P=0.05) and there was a 2.2-fold increase by female gender (OR 2.2, 95% CI 1.1–4.6, P=0.03). In conclusion, morbid obesity represents a BMI threshold above which the odds of complications with AF ablation significantly increase. The increase in complications appears to be driven primarily by events in women suggesting that morbidly obese women are a special population to consider when considering AF ablation.

Background: Symptom clusters have not previously been explored among individuals with atrial fibrillation of any type. Objective: The purpose of this study is to determine the number of symptom clusters present among adults with chronic atrial fibrillation and to explore sociodemographic and clinical factors potentially associated with cluster membership. Methods: This was a cross-sectional secondary data analysis of 335 Australian community-dwelling adults with chronic (recurrent paroxysmal, persistent, or permanent) atrial fibrillation. We used self-reported symptoms and agglomerative hierarchical cluster analysis to determine the number and content of symptom clusters present. Results: There were slightly more male (52%) than female participants, with a mean (SD) age of 72 (11.25) years. Three symptom clusters were evident, including a vagal cluster (nausea and diaphoresis), a tired cluster (fatigue/lethargy, weakness, syncope/dizziness, and dyspnea/breathlessness), and a heart cluster (chest pain/discomfort and palpitations/fluttering). We compared patient characteristics among those with all the symptoms in the cluster, those with some of the symptoms in the cluster, and those with none of the symptoms in the cluster. The only statistically significant differences were in age, gender, and the use of antiarrhythmic medications for the heart cluster. Women were more likely to have the heart symptom cluster than men were. Individuals with all of the symptoms in the heart cluster were younger (69.6 vs 73.7 years; P = .029) than those with none of the symptoms in the heart cluster and were more likely to be on antiarrhythmic medications. Conclusion: Three unique atrial fibrillation symptom clusters were identified in this study population.