Claxton, J’Neka S.

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.

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.

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.

Background Polypharmacy is highly prevalent in elderly people with chronic conditions, including atrial fibrillation ( AF ). The impact of polypharmacy on adverse outcomes and on treatment effectiveness in elderly patients with AF remains unaddressed. Methods and Results We studied 338 810 AF patients ≥75 years of age enrolled in the MarketScan Medicare Supplemental database in 2007–2015. Polypharmacy was defined as ≥5 active prescriptions at AF diagnosis (defined by the presence of International Classification of Diseases, Ninth Revision, Clinical Modification [ ICD‐9‐CM ] codes) based on outpatient pharmacy claims. AF treatments (oral anticoagulation, rhythm and rate control) and cardiovascular end points (ischemic stroke, bleeding, heart failure) were defined based on inpatient, outpatient, and pharmacy claims. Multivariable Cox models were used to estimate associations of polypharmacy with cardiovascular end points and the interaction between polypharmacy and AF treatments in relation to cardiovascular end points. Prevalence of polypharmacy was 52%. Patients with polypharmacy had increased risk of major bleeding (hazard ratio [ HR ], 1.16; 95% CI, 1.12–1.20) and heart failure ( HR , 1.33; 95% CI , 1.29–1.36) but not ischemic stroke ( HR , 0.96; 95% CI , 0.92–1.00), compared with those not receiving polypharmacy. Polypharmacy status did not consistently modify the effectiveness of oral anticoagulants. Rhythm control (versus rate control) was more effective in preventing heart failure hospitalization in patients not receiving polypharmacy ( HR , 0.87; 95% CI , 0.76–0.99) than among those with polypharmacy ( HR , 0.98; 95% CI , 0.91–1.07; P =0.02 for interaction). Conclusion Polypharmacy is common among patients ≥75 with AF , is associated with adverse outcomes, and may modify the effectiveness of AF treatments. Optimizing management of polypharmacy in AF patients ≥75 may lead to improved outcomes.

Background Social determinants of health are relevant to cardiovascular outcomes but have had limited examination in atrial fibrillation (AF). Objectives The purpose of this study was to examine the association of annual household income and cardiovascular outcomes in individuals with AF. Methods We analysed administrative claims for individuals with AF from 2009 to 2015 captured by a health claims database. We categorised estimates of annual household income as <$40 000; $40–$59 999; $60–$74 999; $75–$99 999; and ≥$100 000. Covariates included demographics, education, cardiovascular disease risk factors, comorbid conditions and anticoagulation. We examined event rates by income category and in multivariable-adjusted models in reference to the highest income category (≥$100 000). Results Our analysis included 336 736 individuals (age 72.7±11.9 years; 44.5% women; 82.6% white, 8.4% black, 7.0% Hispanic and 2.1% Asian) with AF followed for median (25th and 75th percentile) of 1.5 (95% CI 0.6 to 3.0) years. We observed an inverse association between income and heart failure and myocardial infarction (MI) with evidence of progressive risk across decreased income categories. Individuals with household income <$40 000 had the greatest risk for heart failure (HR 1.17; 95% CI 1.05 to 1.30) and MI (HR 1.18; 95% CI 0.98 to 1.41) compared with those with income ≥$100 000. Conclusions We identified an association between lower household income and adverse outcomes in a large cohort of individuals with AF. Our findings support consideration of income in the evaluation of cardiovascular risk in individuals with AF.

Background: Polypharmacy is highly prevalent in elderly individuals with chronic conditions, including atrial fibrillation (AF). The impact of polypharmacy on adverse outcomes and on treatment effectiveness in elderly AF patients remains unaddressed. Methods: We studied 338,810 AF patients ≥75 years of age with 1,761,660 active prescriptions [mean (SD), 5.1 (3.8) per patient] enrolled in the MarketScan Medicare Supplemental database in 2007-2015. Polypharmacy was defined as ≥5 active prescriptions at AF diagnosis based on outpatient pharmacy claims. AF treatments (oral anticoagulation, rhythm and rate control) and cardiovascular endpoints (ischemic stroke, bleeding, heart failure) were defined based on inpatient, outpatient and pharmacy claims. Multivariable Cox models were used to estimate associations of polypharmacy with cardiovascular endpoints and the interaction between polypharmacy and AF treatments in relation to cardiovascular endpoints. Results: Prevalence of polypharmacy was 52% (176,007 of 338,810). Patients with polypharmacy had increased risk of major bleeding [hazard ratio (HR) 1.16, 95% confidence interval (CI) 1.12, 1.20] and heart failure (HR 1.33, 95%CI 1.29, 1.36), but not of ischemic stroke (HR 0.96, 95%CI 0.92, 1.00), compared to those not with polypharmacy (Table). Polypharmacy status did not consistently modify the effectiveness of oral anticoagulants. However, rhythm control (vs. rate control) was more effective in preventing heart failure hospitalization in patients not with polypharmacy (HR 0.87, 95%CI 0.76, 0.99) than among those with polypharmacy (HR 0.98, 95%CI 0.91, 1.07, p for interaction = 0.02). Conclusion: Polypharmacy is frequent among elderly patients with AF, associated with adverse outcomes, and potentially affecting the effectiveness of AF treatments. Optimizing management of polypharmacy in elderly AF patients may lead to improved outcomes.

Introduction: 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 for the treatment of AF. 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 75 years or older diagnosed with AF in the MarketScan Medicare database between 2007-2015. Rate control was defined as use of rate control medication or atrioventricular node ablation. Rhythm control was defined by use of anti-arrhythmics, catheter ablation or cardioversion. Participants on both rate and rhythm were coded under rhythm control. We used multivariable logistic and Cox regression models to estimate 1) the association of sex and treatment strategy (within 30-day post AF diagnosis and entire follow-up) and, 2) the association of treatment strategy with incident heart failure, stroke and major bleeding. Results: Men were on average (SD) 82.5 (5.2) years old and women 83.8 (5.6) years, respectively. Women were less likely to receive rhythm control treatment as compared to men in the 30-day post AF diagnosis period (22% vs 27%), (OR 0.91, 95% CI 0.88, 0.94) and over the entire duration of follow-up (28% vs 32%) (HR 0.93, 95% CI 0.90, 0.96). Rhythm (vs. rate) control was associated with a higher risk of heart failure in women [HR 1.41, 95% CI 1.34, 1.49] than in men [HR, 1.21 95% CI 1.15, 1.28] (p for multiplicative interaction < 0.001, Table ). Sex did not modify associations between treatment and incident stroke or major bleeding events. Conclusion: Women aged 75 years and older were less likely to be prescribed rhythm control as compared to men, and experienced higher risk of heart failure than men when receiving rhythm (vs rate) control. Future studies will need to delve into the mechanisms underlying these differences.

Introduction: The prevalence of atrial fibrillation (AF) and multimorbidity increase with age; however, the burden imposed by concurrent conditions on outcomes is unknown. Therefore, we aimed to determine the effect of the number and type of comorbid conditions on outcomes in elderly individuals with incident AF. Methods: Patients with non-valvular AF 75 years and older were identified in the MarketScan Medicare Supplemental database from 2007-2015. Fourteen chronic conditions, defined by two occurrences of a diagnostic code from inpatient and outpatient claims prior to or at the time of AF diagnosis, were obtained and classified into two categories: cardiovascular (CV) or non-CV (listed in Table footnote). We used Cox regression to estimate the associations of the number and type of conditions with stroke, severe bleeding, and heart failure hospitalizations (HF). Results: Among 275,617 patients with AF (mean age 83 years, 51% women), 90% had at least one or more additional chronic conditions. The mean (SD) number of conditions per participant was 1.8 (0.9) for CV conditions and 2.1 (1.2) for non-CV conditions. Over a mean follow-up of 23 months, 7,814 strokes, 13,622 severe bleeds, and 19,252 HF events occurred. After adjustment for age, sex, the number of conditions in the other comorbidity group, an increase of one CV condition was associated with greater risk of stroke, severe bleeding, and HF (Table). In contrast, an increase in one non-CV condition was associated with a lower risk of stroke, and a small increase in bleeding and HF risk (Table). After further adjustments for frailty and medications, the strength of the associations within each group decreased across outcomes. Conclusion: CV conditions in AF patients 75 years and older are more strongly associated with stroke, HF, and bleeding than non-CV conditions. This underscores the effect of CV conditions on CV outcomes in a population in which multimorbidity is most common and health care management and delivery is complex.

Background: Multimorbidity is common in atrial fibrillation (AF); however, the impact of the number and type of comorbid conditions on death and hospitalizations is uncertain. Methods: The prevalence of 17 chronic conditions was obtained in 1430 patients with incident AF from 2000-2010 from Olmsted County, MN. Chronic conditions were ascertained electronically prior to AF and were classified into 3 groups: cardiovascular (CV), other physical, and mental. All hospitalizations and deaths were obtained through 12/31/2014. Associations of the number and type of condition and each individual condition with hospitalizations and death were determined using Andersen-Gill and Cox regression, respectively. Results: Among the 1430 patients with AF (median age 76 years, 48.6% men), the mean (SD) number of chronic conditions was 4.7 (2.7). A total of 4496 hospitalizations and 812 deaths occurred over a mean (SD) follow-up of 5.4 (4.1) years. An increase in the number of conditions of each type was associated with increased risks of death and hospitalizations (Table). Mental conditions (which included depression, anxiety, dementia, schizophrenia, and substance abuse) exhibited the strongest association with death, whereas other physical conditions exhibited the strongest association with hospitalizations. Individual predictors of death included heart failure (HF), hypertension, chronic obstructive pulmonary disease (COPD), chronic kidney disease (CKD), depression, dementia, and substance abuse. Predictors of hospitalizations included HF, coronary artery disease, diabetes, COPD, CKD, arthritis, osteoporosis, and substance abuse. Conclusions: Patients with AF have many comorbid conditions which are associated with death and hospitalizations. Although conditions of each type were associated with outcomes, mental conditions exhibited strongest association with death. These data highlight the importance of management of not only CV comorbidities but other physical and mental comorbidities in patients with AF.

Background Oral anticoagulants ( OACs ) in patients with atrial fibrillation ( AF ), in addition to reducing stroke risk, could also prevent adverse cognitive outcomes. The purpose of this study was to compare the risk of dementia incidence across patients with AF initiating different OAC s. Methods and Results We identified patients with nonvalvular AF initiating OAC s in 2 US healthcare claim databases, MarketScan (2007–2015) and Optum Clinformatics (2009–2015). Dementia, comorbidities, and use of medications were defined on the basis of inpatient and outpatient claims. We performed head‐to‐head comparisons of warfarin, dabigatran, rivaroxaban, and apixaban in propensity score–matched cohorts. We calculated hazard ratios ( HR s) and 95% confidence intervals ( CI s) of incident dementia for each propensity score–matched cohort and meta‐analyzed database‐specific results. We analyzed 307 099 patients with AF from the MarketScan database and 161 346 from the Optum database, of which 6572 and 4391, respectively, had a diagnosis of incident dementia. The mean follow‐up of each cohort ranged between 0.7 and 2.2 years. Patients initiating direct OACs experienced lower rates of 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 rates of dementia comparing direct OAC user groups (dabigatran versus rivaroxaban: HR , 1.02; 95% CI , 0.79–1.32; dabigatran versus apixaban: HR , 0.92; 95% CI , 0.63–1.36; apixaban versus rivaroxaban: HR , 1.01; 95% CI , 0.86–1.19). Conclusions Patients with AF initiating direct OACs experienced lower rates of incident dementia than warfarin users. No obvious benefit was observed for any particular direct OAC in relation to dementia rates.