Objectives To evaluate the association of digoxin with mortality in atrial fibrillation. Background Despite endorsement of digoxin in clinical practice guidelines, there exist limited data on its safety in atrial fibrillation and flutter (AF). Methods Using complete data from the US Department of Veterans Administration (VA) Health Care System, we identified patients with newly-diagnosed, non-valvular AF seen within 90 days in an outpatient setting between VA fiscal years 2004-2008. We used multivariate and propensity-matched Cox proportional hazards to evaluate the association of digoxin use to death. Residual confounding was assessed by sensitivity analysis. Results Of 122,465 patients with 353,168 person-years of follow-up (age 72.1±10.3 years, 98.4% males), 28,679 (23.4%) patients received digoxin. Cumulative mortality rates were higher for digoxin-treated patients than for untreated patients (95 vs. 67 per 1,000 person-years; P<0.001). Digoxin use was independently associated with mortality after multivariate adjustment (HR: 1.26, 95%CI: 1.23-1.29, P<0.001) and propensity matching (HR: 1.21, 95%CI: 1.17-1.25, P<0.001), even after adjustment for drug adherence. The risk of death was not modified by age, sex, heart failure, kidney function, or concomitant use of beta blockers, amiodarone, or warfarin. Conclusion Digoxin was associated with increased risk of death in patients with newly-diagnosed AF, independent of drug adherence, kidney function, cardiovascular comorbidities, and concomitant therapies. These findings challenge current cardiovascular society recommendations on use of digoxin in AF.

Objective To explore gender differences in real-world outcomes after catheter ablation of atrial fibrillation (AF). Background Compared to men, women with AF have greater thromboembolic risk and tend to be more symptomatic. Catheter ablation is generally more effective than antiarrhythmic drug therapy alone. However, there is limited data on the influence of gender on AF ablation outcomes. Methods We analyzed medical claims of 45 million United States patients enrolled in a variety of employee-sponsored and fee-for-service plans. We identified patients who underwent an AF ablation from 2007 to 2011 and evaluated 30-day safety and one-year effectiveness outcomes. Results Of the 21,091 patients who underwent an AF ablation, 7,460 (29%) were female. Women, compared to men, were older (62±11 vs. 58±11 years), had higher CHADS2 (1.2±1.1 vs. 1.0±1.0), higher CHA2DS2-VASc (2.9±1.5 vs. 1.6±1.4), and higher Charlson comorbidity index scores (1.2±1.3 vs. 1.0±1.2)(p<0.001 for all). Following ablation, women had higher risk of 30-day complications of hemorrhage (2.7 vs. 2.0%,p<0.001) and tamponade (3.8 vs. 2.9%,p<0.001). In multivariable analyses, women were more likely to have a re-hospitalization for AF (adjusted HR 1.12,p=0.009), but less likely to have repeat AF ablation (adjusted HR 0.92,p=0.04) or cardioversion (adjusted HR 0.75,p<0.001). Conclusion Women have increased hospitalization rates after AF ablation and are more likely to have a procedural complication. Despite the higher rate of hospital admissions for AF after ablation, women were less likely to undergo repeat ablation or cardioversion. These data call for greater examination of barriers and facilitators to sustain rhythm control strategies in women.

BackgroundIdentification of silent atrial fibrillation (AF) could prevent stroke and other sequelae.HypothesisScreening for AF using continuous ambulatory electrocardiographic (ECG) monitoring can detect silent AF in asymptomatic in patients with known risk factors.MethodsWe performed a single-center prospective screening study using a wearable patch-based device that provides up to 2 weeks of continuous ambulatory ECG monitoring (iRhythm Technologies, Inc.). Inclusion criteria were age ≥55 years and ≥2 of the following risk factors: coronary disease, heart failure, hypertension, diabetes, sleep apnea. We excluded patients with prior AF, stroke, transient ischemic attack, implantable pacemaker or defibrillator, or with palpitations or syncope in the prior year.ResultsOut of 75 subjects (all male, age 69 ± 8.0 years; ejection fraction 57% ± 8.7%), AF was detected in 4 subjects (5.3%; AF burden 28% ± 48%). Atrial tachycardia (AT) was present in 67% (≥4 beats), 44% (≥8 beats), and 6.7% (≥60 seconds) of subjects. The combined diagnostic yield of sustained AT/AF was 11%. In subjects without sustained AT/AF, 11 (16%) had ≥30 supraventricular ectopic complexes per hour.ConclusionsOutpatient extended ECG screening for asymptomatic AF is feasible, with AF identified in 1 in 20 subjects and sustained AT/AF identified in 1 in 9 subjects, respectively. We also found a high prevalence of asymptomatic AT and frequent supraventricular ectopic complexes, which may be relevant to development of AF or stroke. If confirmed in a larger study, primary screening for AF could have a significant impact on public health.

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Background— The temporal relationship of atrial fibrillation (AF) and stroke risk is controversial. We evaluated this relationship via a case-crossover analysis of ischemic strokes in a large cohort of patients with cardiac implantable electronic devices. Methods and Results— We identified 9850 patients with cardiac implantable electronic devices remotely monitored in the Veterans Administration Health Care System between 2002 and 2012. There were 187 patients with acute ischemic stroke and continuous heart rhythm monitoring for 120 days before the stroke (age, 69±8.4 years; 98% with an implantable defibrillator). We compared each patient’s daily AF burden in the 30 days before stroke (case period) with their AF burden during days 91 to 120 pre stroke (control period). Defining positive AF burden as ≥5.5 hours of AF on any given day, 156 patients (83%) had no positive AF burden in both periods and, in fact, had little to no AF; 15 (8%) patients had positive AF burden in both periods. Among the discordant (informative) patients, 13 exceeded 5.5 hours of AF in the case period but not in the control period, whereas 3 had positive AF burden in the control but not in the case period (warfarin-adjusted odds ratio for stroke, 4.2; 95% confidence interval, 1.5–13.4). Odds ratio for stroke was highest (17.4; 95% confidence interval, 5.39–73.1) in the 5 days immediately after a qualifying occurrence of AF and decreased toward 1.0 as the period after the AF occurrence increased beyond 30 days. Conclusions— In this population with continuous heart rhythm recording, multiple hours of AF had a strong but transient effect raising stroke risk.