Abstract Background: Women with atrial fibrillation (AF) experience greater symptomatology, worse quality of life, and have a higher risk of stroke as compared to men, but are less likely to receive rhythm control treatment. Whether these differences exist in elderly patients with AF, and whether sex modifies the effectiveness of rhythm versus rate control therapy has not been assessed.Methods: We studied 135,850 men and 139,767 women aged ≥75 years diagnosed with AF in the MarketScan Medicare database between 2007-2015. Anticoagulant use was defined as use of warfarin or a direct oral anticoagulant. Rate control was defined as use of rate control medication or atrioventricular node ablation. Rhythm control was defined by use of anti-arrhythmic medication, catheter ablation or cardioversion. We used multivariable Poisson and Cox regression models to estimate the association of sex with treatment strategy and to determine whether the association of treatment strategy with adverse outcomes (bleeding, heart failure and stroke) differed by sex. Results: At the time of AF, women were on average (SD) 83.8 (5.6) years old and men 82.5 (5.2) years, respectively. Compared to men, women were less likely to receive an anticoagulant or rhythm control treatment. Rhythm control (vs. rate) was associated with a greater risk for heart failure with a significantly stronger association in women (HR women = 1.41, 95%CI 1.34-1.49; HR men= 1.21, 95%CI 1.15-1.28, p <0.0001 for interaction). No sex differences were observed for the association of treatment strategy with the risk of bleeding or stroke. Conclusion: Sex differences exist in the treatment of AF among patients aged 75 years and older. Women are less likely to receive an anticoagulant and rhythm control treatment. Women were also at a greater risk of experiencing heart failure as compared to men, when treated with rhythm control strategies for AF. Efforts are needed to enhance use AF therapies among women. Future studies will need to delve into the mechanisms underlying these differences.
Identified Enrollment Challenges of Adolescent and Young Adult Patients on the Nonchemotherapy Arm of Children's Oncology Group Study ARST1321
ARST1321, a trial of patients with advanced soft tissue sarcoma, was the first National Clinical Trials Network study codeveloped by pediatric and adult consortia with two treatment cohorts. We report on the findings of a survey to identify barriers to enrolling adolescent and young adult patients (15–39 years) onto the nonchemotherapy arm. The survey response rate was 31% with a 70% completion rate. Common identified reasons for low accrual in order of decreasing frequency included insufficient funding, lack of study awareness or interest, competing trials, toxicity concerns, philosophical differences in the therapy backbone, and regulatory and infrastructure barriers. Clinical Trials.gov ID: NCT02180867.
Directed stimulation of the dentato-rubro-thalamic tract for deep brain stimulation in essential tremor: a blinded clinical trial
Objective Observational studies utilising diffusion tractography have suggested a common mechanism for tremor alleviation in deep brain stimulation for essential tremor: the decussating portion of the dentato-rubro-thalamic tract. We hypothesised that directional stimulation of the dentato-rubro-thalamic tract would result in greater tremor improvement compared to sham programming, as well as comparable improvement as more tedious standard-of-care programming. Methods A prospective, blinded crossover trial was performed to assess the feasibility, safety and outcomes of programming based solely on dentato-rubro-thalamic tract anatomy. Using magnetic resonance imaging diffusion-tractography, the dentato-rubro-thalamic tract was identified and a connectivity-based treatment setting was derived by modelling a volume of tissue activated using directional current steering oriented towards the dentato-rubro-thalamic tract centre. A sham setting was created at approximately 180° opposite the connectivity-based treatment. Standard-of-care programming at 3 months was compared to connectivity-based treatment and sham settings that were blinded to the programmer. The primary outcome measure was percentage improvement in the Fahn–Tolosa–Marín tremor rating score compared to the preoperative baseline. Results Among the six patients, tremor rating scores differed significantly among the three experimental conditions ( P=0.030). The mean tremor rating score improvement was greater with the connectivity-based treatment settings (64.6% ± 14.3%) than with sham (44.8% ± 18.6%; P=0.031) and standard-of-care programming (50.7% ± 19.2%; P=0.062). The distance between the centre of the dentato-rubro-thalamic tract and the volume of tissue activated inversely correlated with the percentage improvement in the tremor rating score (R 2 =0.24; P=0.04). No significant adverse events were encountered. Conclusions Using a blinded, crossover trial design, we have shown the technical feasibility, safety and potential efficacy of connectivity-based stimulation settings in deep brain stimulation for treatment of essential tremor.
Brain structural differences in temporal lobe and frontal lobe epilepsy patients: A voxel-based morphometry and vertex-based surface analysis
Purpose Exploration of the effect of chronic recurrent seizures in focal epilepsy on brain volumes has produced many conflicting reports. To determine differences in brain structure in temporal lobe epilepsy (TLE) and extratemporal epilepsy (using frontal lobe epilepsy (FLE) a surrogate) further, we performed a retrospective analysis of a large cohort of patients with seizure-onset zone proven by intracranial monitoring. Methods A total of 120 TLE patients, 86 FLE patients, and 54 healthy controls were enrolled in this study. An analysis of variance of voxel-based morphometry (VBM) was used to seek morphometric brain differences among TLE patients, FLE patients, and healthy controls. Additionally, a vertex-based surface analysis was utilized to analyze the hippocampus and thalamus. Significant side-specific differences in hippocampal gray matter volume were present between the left TLE (LTLE), right TLE RTLE (RTLE), and control groups ( p<0.05, family-wise error (FWE) corrected). Results Vertex analyses revealed significant volume reduction in inferior parts of the left hippocampus in the LTLE group and lateral parts of the right hippocampus in the RTLE group compared to controls ( p<0.05, FWE corrected). Significant differences were also detected between the LTLE and control group in the bilateral medial and inferior thalamus ( p<0.05, FWE corrected). FLE patients did not exhibit focal atrophy of gray matter across the brain. Conclusion Our results highlight the variation in morphometric lateralized changes in the brain between different epilepsy onset zones, providing critical insight into the natural history of people with drug-resistant focal epilepsies.
Acute Brain Activation Patterns of High- Versus Low-Frequency Stimulation of the Anterior Nucleus of the Thalamus During Deep Brain Stimulation for Epilepsy
Abstract BACKGROUND Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is an increasingly utilized treatment of drug-resistant epilepsy. To date, the effect of high-frequency stimulation (HFS) vs low-frequency stimulation (LFS) in ANT DBS is poorly understood. OBJECTIVE To assess differences in the acute effect of LFS vs HFS in ANT DBS utilizing blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI). METHODS In this prospective study of 5 patients with ANT DBS for epilepsy, BOLD activation and deactivation were modeled for 145-Hz and 30-Hz ANT stimulation using an fMRI block design. Data were analyzed with a general linear model and combined via 2-stage mixed-effects analysis. Z-score difference maps were nonparametrically thresholded using cluster threshold of z > 3.1 and a (corrected) cluster significance threshold of P = .05. RESULTS HFS produced significantly greater activation within multiple regions, in particular the limbic and default mode network (DMN). LFS produced minimal activation and failed to produce significant activation within these same networks. HFS produced widespread cortical and subcortical deactivation sparing most of the limbic and DMN regions. Meanwhile, LFS produced deactivation in most DMN and limbic structures. CONCLUSION Our results show that HFS and LFS produce substantial variability in both local and downstream network effects. In particular, largely opposing effects were identified within the limbic network and DMN. These findings may serve as a mechanistic basis for understanding the potential of HFS vs LFS in various epilepsy syndromes.
Abstract P113: New-onset Atrial Fibrillation and Risk of Mortality and Cardiovascular Disease in Whites and African Americans: the ARIC Study
Background: Multiple studies have shown that atrial fibrillation (AF), a common cardiac arrhythmia, is associated with increased mortality and higher incidence of stroke and heart failure. However, evidence for this association in African Americans is lacking. Methods: We studied 4,063 African Americans and 11,280 whites in the Atherosclerosis Risk in Communities (ARIC) Study, a US community-based cohort study, aged 45-64 (55% women) and free of AF at baseline in 1987-89. Three additional follow-up exams were conducted in 1990-92, 1993-95, and 1996-98. AF was ascertained during follow-up with study visit ECGs and hospital surveillance. Mortality and incidence of stroke and heart failure were ascertained according to study protocols. Using multivariable Cox proportional hazards models with time-dependent covariates, we calculated hazard ratios (HR) and 95% confidence intervals (CI) of mortality, stroke and heart failure in those with new-onset AF compared to those without AF by race. Results: During an average follow-up of 18 years, 332 AF cases were ascertained in African Americans and 1407 in whites. Overall, African Americans showed higher all-cause mortality and cardiovascular disease rates than whites ( Table ). AF was associated with increased mortality and risk of incident stroke and heart failure in whites and African Americans, even after adjustment for baseline and time-dependent potential confounders ( Table ). Associations of AF with all-cause mortality and stroke were of similar magnitude in both racial groups. However, the association between AF and heart failure was stronger in whites than in African Americans (HR 3.6, 95% CI 3.1-4.2 in whites, vs. HR 2.2, 95% CI 1.6-3.0 in African Americans). Conclusion: New-onset AF was associated with an increased risk of all-cause mortality, stroke, and heart failure in whites and African Americans independently of other cardiovascular risk factors. Table. Hazard ratios (95% confidence interval) of all-cause mortality, stroke, and heart failure in those with new-onset atrial fibrillation (AF) versus those without AF by race, ARIC, 1987-2008 Blacks Whites P for interaction No AF (n=3731) AF (n=332) No AF (n=9873) AF (n=1407) Mortality Deaths (n) 1144 188 2042 630 Person-years 69,483 1268 200,878 7493 Mortality rate 1 18.6 126.3 10.1 62.3 Model 1 1 (ref.) 5.80 (4.93-6.82) 1 (ref.) 4.58 (4.17-5.04) 0.27 Model 2 1 (ref.) 3.20 (2.71-3.76) 1 (ref.) 2.87 (2.61-3.17) 0.68 Stroke Events (n) 281 23 347 64 Person-years 51,082 867 147,608 5040 Incidence rate 1 6.0 25.0 2.4 11.5 Model 1 1 (ref.) 2.91 (1.81-4.68) 1 (ref.) 2.52 (1.86-3.43) 0.94 Model 2 1 (ref.) 1.83 (1.13-2.96) 1 (ref.) 1.91 (1.39-2.62) 0.82 Heart failure Events 613 71 992 364 Person-years 62,570 721 187,847 4578 Incidence rate 1 10.7 108.1 5.3 76.1 Model 1 1 (ref.) 3.35 (2.41-4.65) 1 (ref.) 4.75 (4.09-5.51) 0.02 Model 2 1 (ref.) 2.18 (1.56-3.04) 1 (ref.) 3.63 (3.12-4.21) 0.0006 1 Age- and sex-standardized, per 1000 person-years; Model 1 : Cox proportional hazards model adjusted for age, sex, and study center, with AF incidence as a time-dependent covariate; Model 2 : As model 1, but additionally adjusting for baseline education, and time-dependent body mass index, smoking, diabetes, hypertension, stroke, heart failure, and myocardial infarction Funding(This research has received full or partial funding support from the American Heart Association, National Center)
Abstract P004: Impact of Atrial Fibrillation on Healthcare Utilization in the Community: The Atherosclerosis Risk in Communities (ARIC) Study
Background: Atrial fibrillation (AF) is associated with increased risk of hospitalization. However, little is known about the impact of AF on non-inpatient healthcare utilization or about sex or race differences in AF-related utilization. We examined rates of inpatient and outpatient utilization by AF status in the Atherosclerosis Risk in Communities (ARIC) study. Methods and Results: ARIC cohort participants with incident AF enrolled in fee-for-service Medicare, Parts A and B, for at least 12 continuous months between 1991 and 2009 were matched on age, sex, race and center to up to three participants without AF. Healthcare utilization was ascertained from inpatient and outpatient Medicare claims and classified based on primary ICD-9 code. The analysis included 944 AF and 2,761 non-AF participants. The average number of days hospitalized per year was 13.1 (95% confidence interval [CI]: 11.5-15.0) and 2.8 (95% CI: 2.5-3.1) for those with and without AF, respectively. The corresponding number of outpatient claims per year was 53.2 (95% CI: 50.4-56.1) and 23.0 (95% CI: 22.2-23.8) for those with and without AF, respectively (Table). Most utilization in AF patients was attributable to non-AF conditions, particularly other-cardiovascular disease (CVD)-related reasons; the adjusted rate ratio for days hospitalized per year for other-CVD-related reasons was 4.76 (95% CI: 3.51 - 6.44) for those with compared to those without AF. There was suggestive evidence that sex modified the association between AF and inpatient utilization, with AF related to greater utilization in women than men. The association between AF and healthcare utilization was similar in whites and blacks. Conclusions: This study highlights the considerably greater healthcare utilization (inpatient and outpatient) among those with AF; the differential in utilization due to other-CVD-related reasons was substantial. In addition to recommended heart rate or rhythm treatment, accompanying cardiovascular comorbidities should be evaluated and managed.
Abstract P003: Survival after Incident Atrial Fibrillation: A Community-Based Study
Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice, causes substantial morbidity, and is associated with an excess risk of mortality. However, information on contemporary time trends in survival after AF is lacking. Thus, we aimed to determine whether survival after incident AF has changed over the last decade in a community-based cohort of 3413 individuals with incident AF between 2000 and 2010. Methods: Olmsted County, MN residents 18 years of age and older with a first-ever AF or atrial flutter event between 2000 and 2010 were identified using inpatient and outpatient diagnostic codes and electrocardiograms. Deaths from any cause were ascertained through August 31, 2012 and time trends in survival after AF were examined using Kaplan-Meier curves and Cox proportional hazards regression. Results: Among 3413 individuals with incident AF (52% men, age range 18-104) between 2000 and 2010, 1561 deaths were observed over a median follow-up of 3.4 years. Survival did not differ by year of AF diagnosis (figure). In addition, the proportion of cardiovascular disease-related deaths compared to non-cardiovascular deaths did not differ over time. After adjustment for age, sex, and Charlson comorbidity index, the hazard ratios for all-cause mortality were 1.09 (95% CI 0.97-1.23) for those diagnosed with AF in 2004-2007 vs. 2000-2003 and 1.04 (95% CI 0.90-1.12) for 2008-2010 vs. 2000-2003. Furthermore, the risk of death did not differ by sex after adjustment for age and comorbidity (HR 1.00, 95% CI 0.90-1.11 for men vs. women). Conclusions: In the community, survival after AF has remained constant over the last decade despite substantial changes in the recommendations for treatment of AF. This underscores the importance of identification of prognostic factors and continued surveillance of outcomes in AF, as well as a better understanding of how to optimize the management of AF to improve outcomes in these patients.
Abstract P021: Oral Anticoagulant Use and Risk of Incident Dementia in Persons With Atrial Fibrillation
Background: Current guidelines recommend oral anticoagulation for the prevention of stroke in most patients with atrial fibrillation (AF). Direct oral anticoagulants (DOACs) are associated with lower risk of ischemic stroke and intracranial bleeding than warfarin and, therefore, may reduce risk of dementia among patients with AF. Hypothesis: AF patients initiating DOACs for stroke prevention will have lower risk of dementia than patients initiating warfarin. Methods: We used data from two US healthcare claim databases, MarketScan (2007-2015) and Optum Clinformatics (2009-2015). Using validated algorithms, we identified patients with AF who initiated oral anticoagulation. Dementia was defined as having an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) code of 290.xx, 294.xx, or 331.0. Comorbidities and use of other medications were defined based on inpatient, outpatient, and pharmacy claims. We performed a series of head-to-head comparisons of different oral anticoagulants (warfarin, dabigatran, rivaroxaban, and apixaban) in propensity score-matched cohorts. In each database, multivariable-adjusted Cox regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia for each comparison of propensity score-matched cohorts, adjusting for age, sex, comorbidities, use of other medications, and markers of socioeconomic status (in the Optum database only). We meta-analyzed database-specific results using a random-effects model. Results: The analysis included 307,099 AF patients from the MarketScan database and 161,346 from the Optum database, of which 6,572 and 4,391 respectively had a diagnosis of incident dementia. Mean follow up ranged between 0.7 to 2.3 years and incident of diagnosed dementia between 7 to 14 cases per 1000 person-years across different oral anticoagulant initiator groups. Patients initiating DOACs had a lower risk of incident dementia than those initiating warfarin (dabigatran: HR 0.85, 95%CI 0.71, 1.01; rivaroxaban: HR 0.85, 95%CI 0.76, 0.94; apixaban: HR 0.80, 95%CI 0.65, 0.97). There were no differences in risk of incident dementia comparing DOAC user groups (dabigatran vs. rivaroxaban: HR 1.02, 95%CI 0.79, 1.32; dabigatran vs. apixaban: HR 0.92, 95%CI 0.63, 1.36; apixaban vs. rivaroxaban: HR 1.01, 95%CI 0.86, 1.19). Conclusions: Patients with AF initiating DOACs experienced lower rates of incident dementia than warfarin users. No obvious benefit was observed for any particular DOAC in relation to dementia rates.
Abstract 013: A Model for Stroke Prediction Using Claims Data in a Contemporary Cohort of Patients With Atrial Fibrillation Receiving Oral Anticoagulation
Background: Oral anticoagulants (OACs) are recommended for AF patients for the prevention of thromboembolic events, including stroke. Stroke risk stratification scores (e.g., CHA 2 DS 2 -VASc) are used to tailor therapeutic recommendations for patients in different risk groups. However, these were derived before the advent of direct OACs. At present, there is no tool that estimates a patient’s stroke risk, given their individual characteristics, by type of OAC. Methods: We used healthcare utilization data from two independent US databases (MarketScan and Optum) to construct and validate a predictive model of ischemic stroke in patients with AF initiating OACs. Patients with non-valvular AF initiating OACs were identified from the MarketScan data for years 2007-2015. Using bootstrapping methods and backward selection of 44 candidate variables, we developed a model which selected variables predicting stroke. The final model was validated in patients with non-valvular AF in the Optum Clinformatics database in the period 2009-2015. Results: Among 135,523 patients with AF initiating OAC in the MarketScan dataset, 2,028 experienced an ischemic stroke after anticoagulant initiation. The stepwise model identified 15 variables (including type of OAC) associated with ischemic stroke (Table). The discrimination (c-statistic) of the model was adequate [0.68, 95% confidence interval (CI) 0.66-0.70], showing excellent calibration (χ 2 = 7.7 p=0.57). The model was then applied to the 84,549 AF patients in the Optum data set (1408 stroke events). The model showed similar discrimination (c-statistic 0.67, 95%CI 0.65-0.70) and calibration (χ 2 = 12.8 p=0.17). However, previously-developed predicted models had similar discriminative ability (CHA 2 DS 2 -VASc 0.67, 95%CI 0.65-0.68; ATRIA 0.67, 95%CI 0.65-0.68) Conclusion: A novel model using extensive administrative healthcare data for the identification of patients at higher risk of ischemic stroke by type of anticoagulant did not perform better than established simple models.