Bengtson, Lindsay G.S.

Introduction: Isolated cases of liver injury associated with the use of non-vitamin K antagonist oral anticoagulants (NOACs) have been reported. However, the comparative incidence of liver injury in users of different oral anticoagulants is unknown. Methods: We studied 113,717 patients (mean age 70, 39% women) with non-valvular atrial fibrillation (AF) included in the MarketScan® Commercial and Medicare Supplemental databases with a first prescription for oral anticoagulation after November 4, 2011, followed through December 31, 2014. Of these, 56,879 initiated warfarin, 17,286 initiated dabigatran, 30,347 initiated rivaroxaban, and 9,205 initiated apixaban. Liver injury hospitalizations were identified using selected inpatient diagnostic codes. Multivariable Cox models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of liver injury by anticoagulant type. Results: During a median follow-up of 12 months, 960 hospitalizations with liver injury were identified. Rates of liver injury hospitalization (per 1000 person-years) by oral anticoagulant were 9.0 (warfarin), 4.0 (dabigatran), 6.6 (rivaroxaban), and 5.6 (apixaban). After multivariable adjustment, rates of liver injury hospitalization were lower in initiators of NOACs compared to warfarin: HR (95%CI) of 0.57 (0.46, 0.71), 0.88 (0.75, 1.03) and 0.70 (0.50, 0.97) for initiators of dabigatran, rivaroxaban, and apixaban, respectively (Table). Compared to dabigatran initiators, rivaroxaban initiators had a 56% increased risk of liver injury hospitalization (HR 1.56, 95%CI 1.22, 1.99). In addition to type of anticoagulant, prior liver, gallbladder, and kidney disease, cancer, anemia, heart failure, and alcoholism significantly predicted liver injury hospitalization. Conclusions: Among patients with non-valvular AF, NOACs were associated with lower risk of liver injury hospitalization compared to warfarin, with dabigatran showing the lowest risk.

Background: Women and African Americans with atrial fibrillation (AF) experience higher rates of stroke compared to men and white AF patients, respectively. However, sex and race differences for cardiovascular outcomes other than stroke have not been specifically evaluated in patients with AF. Methods: We studied patients with AF in the Optum Clinformatics database between 2009 and 2015 with at least 6 months of enrollment before AF diagnosis. The Optum Clinformatics database includes medical and pharmacy claims and sociodemographic information on privately insured and Medicare Advantage enrollees throughout the US. Endpoints (hospitalizations for ischemic stroke, heart failure (HF), myocardial infarction (MI)) and covariates were defined using validated algorithms. Multivariable Cox models were used to study the association of race and sex with endpoints of interest. Results: The analysis included 380,636 eligible participants (mean age 73, women 45%). Of them, 82% were white, 9% African American, 7% Hispanic and 2% Asian American. During a mean follow-up of 23 months, 7,235 suffered ischemic stroke, 17,258 HF, and 5,585 MI. Crude rates of ischemic stroke and HF were higher in women than men, while men had higher rates of MI than women (Table). African Americans and Hispanics had higher rates of all studied outcomes than whites and Asian Americans. In models including age, sex, race, education and CHA 2 DS 2 -VASc score, women had higher risk of ischemic stroke and lower risk of HF and MI compared to men. Compared to whites, African Americans had 1.4 times the rate of HF and stroke, and 1.1 times the rate of MI, while Asian Americans had 16% lower rates of HF. No major differences were observed between rates in whites and Hispanics (Table). Conclusion: In a large insured population of patients with AF, we observed differences in rates of selected cardiovascular outcomes by sex and race. Additional research should explore the mechanisms underlying these differences and develop strategies to eliminate them.

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 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.

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 and Purpose— Despite modest predictive ability for ischemic stroke (IS), the CHA 2 DS 2 -VASc score is widely used for stroke prediction in atrial fibrillation. Among patients with atrial fibrillation, we aimed to (1) compare the IS or transient ischemic attack (TIA) incidence by CHA 2 DS 2 -VASc in blacks and Hispanics versus whites; (2) compare predictive ability of CHA 2 DS 2 -VASc score for IS or TIA in blacks and Hispanics versus whites; and (3) determine improvement in predictive ability of CHA 2 DS 2 -VASc score from addition of race/ethnicity. Methods— Using data from Optum Clinformatics, a large administrative claims database, we analyzed patients with atrial fibrillation enrolled in commercial and Medicare Advantage health plans from 2009 to 2015. We computed IS or TIA incidence rates, improvement in C statistic, continuous and categorical net reclassification improvement, and relative integrated discrimination improvement from addition of race/ethnicity to CHA 2 DS 2 -VASc. Results— A total of 267 419 patients (mean age, 73.1 [SD, 12.3] years; 46.6% women; 84.2% white, 8.5% black, 7.3% Hispanic) were studied. After a mean follow-up of 22 months, there were 6202 IS or TIA events. IS or TIA incidence rates were higher in blacks than Hispanics or whites (1.65, 1.40, and 1.22 cases per 100 person-years, respectively) and increased with higher CHA 2 DS 2 -VASc, with no race/ethnicity-based differences ( P for interaction=0.17). The CHA 2 DS 2 -VASc and CHA 2 DS 2 -VASc+race/ethnicity C statistic (95% CI) were 0.679 (0.670–0.686) and 0.679 (0.671–0.688). The CHA 2 DS 2 -VASc C statistic in the 3 groups were comparable. With addition of race/ethnicity, the categorical net reclassification improvement, continuous net reclassification improvement, and relative integrated discrimination improvement were −0.045 (95% CI, −0.067 to −0.025), 0.045 (95% CI, 0.025–0.068), and 0.016 (95% CI, 0.014–0.018). Conclusions— The predictive ability of CHA 2 DS 2 -VASc for IS or TIA in atrial fibrillation is comparable among whites, blacks, and Hispanics; hence, it can be used in the latter 2 groups. Addition of race/ethnicity to the CHA 2 DS 2 -VASc does not improve its predictive ability.

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.

Background Differences in anticoagulation rates and direct oral anticoagulant use by provider specialty may identify an area of practice improvement to reduce future stroke events in patients with atrial fibrillation ( AF ). Methods and Results We examined anticoagulant prescription fills in 388 045 (mean age, 68±15 years; 59% male) patients with incident AF from the MarketScan databases between 2009 and 2014. Provider specialty and filled anticoagulant prescriptions around the time of AF diagnosis (3 months before through 6 months after) were obtained from outpatient services and pharmacy claims. We estimated the association of provider specialty (cardiology versus primary care) with filling oral anticoagulant prescriptions, adjusting for patient characteristics. The risk of stroke and bleeding events also was explored. A total of 235 739 patients (61%) had a cardiology provider claim, whereas 152 306 (39%) were exclusively managed by primary care. Patients seen by cardiology providers were more likely to fill anticoagulant prescriptions than those seen by primary care (39% versus 27%; relative risk, 1.39; 95% confidence interval [ CI ], 1.37–1.40). Differences were observed for direct oral anticoagulants (relative risk, 1.74; 95% CI , 1.71–1.78) and warfarin (relative risk, 1.24; 95% CI , 1.22–1.26). A reduced risk of stroke events was observed among those seen by cardiology providers (hazard ratio, 0.90; 95% CI , 0.86–0.94) compared with primary care, without an increased bleeding risk (hazard ratio, 1.03; 95% CI , 0.98–1.07). Conclusions Patients seen by an outpatient cardiology provider shortly after AF diagnosis were more likely to initiate oral anticoagulation and were at lower risk of future stroke events without a higher rate of bleeding. Early referral to cardiology specialists may increase initiation of anticoagulant therapies and improve outcomes in AF .