Background: Stroke risk stratification scores (eg, CHA2DS2-VASc) are used to tailor therapeutic recommendations for patients with atrial fibrillation (AF) in different risk groups. Objective: The purpose of this study was to develop a tool to estimate stroke risk in patients receiving oral anticoagulants (OACs) and to identify patients who remain at high risk for stroke despite anticoagulation therapy. Methods: Patients with nonvalvular AF initiating OACs were identified in the MarketScan data from 2007 to 2015. Using bootstrapping methods and backward selection of 44 candidate variables, we developed a model that selected variables predicting stroke. The final model was validated in patients with nonvalvular AF in the Optum database in the period 2009–2015. In both databases, the discrimination of existing stroke scores were individually evaluated and compared with our new model termed the AntiCoagulaTion-specific Stroke (ACTS) score. Results: Among 135,523 patients with AF initiating OACs in the MarketScan dataset, 2028 experienced an ischemic stroke after anticoagulant initiation. The stepwise model identified 11 variables (including type of OAC) associated with ischemic stroke. The discrimination (C statistic) of the model was adequate (0.68; 95% confidence interval [CI] 0.66–0.70), showing excellent calibration (χ2 = 6.1; P = .73). ACTS was then applied to 84,549 AF patients in the Optum dataset (1408 stroke events) and showed similar discrimination (C statistic 0.67; 95% CI 65-0.69). However, previously developed predictive models had similar discriminative ability (CHA2DS2-VASc 0.67; 95% CI 0.65–0.68). Conclusion: A novel model to identify AF patients at higher risk of ischemic stroke, using extensive administrative health care data including type of anticoagulant, did not perform better than established simpler models.

Understanding of the comparative bleeding risks of oral anticoagulant (OAC) therapies for the primary treatment of venous thromboembolism (VTE) is limited. Therefore, among anticoagulant-naïve VTE patients, we conducted comparisons of apixaban, rivaroxaban and warfarin on the rate of hospitalised bleeding within 180 days of OAC initation. MarketScan databases for the time-period from 2011 to 2016 were used and, for each OAC comparison, new users were matched with up to five initiators of a different OAC. The final analysis included 83 985 VTE patients, who experienced 1944 hospitalised bleeding events. In multivariable-adjusted Cox regression models, rate of hospitalised bleeding was lower among new users of apixaban when compared to new users of rivaroxaban [hazard ratio (95% confidence interval) 0·58 (0·41–0·80)] or warfarin [0·68 (0·50–0·92)]. Overall, the hospitalised bleeding rate was similar when comparing new users of rivaroxaban to new users of warfarin [0·98 (0·68–1·11)], though there was some suggestion that rivaroxaban was associated with lower bleeding risk among younger individuals. Findings from this large real-world population concur with results from the randomised trial which found lower bleeding risk with apixaban versus warfarin and, for the first time, reveal a lower risk of bleeding in a comparison of apixaban versus rivaroxaban.

The electrocardiographic PR interval reflects atrioventricular conduction, and is associated with conduction abnormalities, pacemaker implantation, atrial fibrillation (AF), and cardiovascular mortality. Here we report a multi-ancestry (N = 293,051) genome-wide association meta-analysis for the PR interval, discovering 202 loci of which 141 have not previously been reported. Variants at identified loci increase the percentage of heritability explained, from 33.5% to 62.6%. We observe enrichment for cardiac muscle developmental/contractile and cytoskeletal genes, highlighting key regulation processes for atrioventricular conduction. Additionally, 8 loci not previously reported harbor genes underlying inherited arrhythmic syndromes and/or cardiomyopathies suggesting a role for these genes in cardiovascular pathology in the general population. We show that polygenic predisposition to PR interval duration is an endophenotype for cardiovascular disease, including distal conduction disease, AF, and atrioventricular pre-excitation. These findings advance our understanding of the polygenic basis of cardiac conduction, and the genetic relationship between PR interval duration and cardiovascular disease.

Background and Purpose: Despite modest predictive ability for ischemic stroke (IS), the CHA2DS2-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 CHA2DS2-VASc in blacks and Hispanics versus whites; (2) compare predictive ability of CHA2DS2-VASc score for IS or TIA in blacks and Hispanics versus whites; and (3) determine improvement in predictive ability of CHA2DS2-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 CHA2DS2-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 CHA2DS2-VASc, with no race/ethnicity-based differences (P for interaction=0.17). The CHA2DS2-VASc and CHA2DS2-VASc+race/ethnicity C statistic (95% CI) were 0.679 (0.670-0.686) and 0.679 (0.671-0.688). The CHA2DS2-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 CHA2DS2-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 CHA2DS2-VASc does not improve its predictive ability.

Background Prolongation of the QT interval has been associated with an increased risk of developing atrial fibrillation (AF), but the responsible mechanism remains unknown. Objectives The aims of this study were to subdivide the QT interval into its components and identify the resultant electrocardiographic interval(s) responsible for the association with AF. Methods Predefined QT-interval components were assessed for association with incident AF in the Atherosclerosis Risk in Communities study using Cox proportional hazards models. Hazard ratios (HRs) were calculated per 1-SD increase in each component. Among QT-interval components exhibiting significant associations, additional analyses evaluating long extremes, defined as greater than the 95th percentile, were performed. Results Of the 14,625 individuals, 1505 (10.3%) were diagnosed with incident AF during a mean follow-up period of 17.6 years. After multivariable adjustment, QT-interval components involved in repolarization, but not depolarization, exhibited significant associations with incident AF, including a longer ST segment (HR 1.27; 95% confidence interval [CI] 1.14–1.41; P <.001) and a prolonged T-wave onset to T-wave peak (T-onset to T-peak) (HR 1.13; 95% CI 1.07–1.20; P <.001). Marked prolongation of the ST segment (HR 1.31; 95% CI 1.04–1.64; P =.022) and T-onset to T-peak (HR 1.36; 95% CI 1.09–1.69; P =.006) was also associated with an increased risk of incident AF. Conclusion The association between a prolonged QT interval and incident AF is primarily explained by components involved in ventricular repolarization: prolongation of the ST segment and T-onset to T-peak. These observations suggest that prolongation of phases 2 and 3 of the cardiac action potential drives the association between the QT interval and AF risk.

Background Circulating NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, a well-known indicator of atrial wall stress and remodeling, inversely correlate with body mass index. Both are strongly predictive of atrial fibrillation (AF). Their potential interaction in relation to incident AF, however, has not been explored. Methods and Results In total, 9556 participants of the ARIC (Atherosclerosis Risk in Communities) study who had 2 measurements of NT-proBNP and no baseline AF or heart failure were followed from 1996 to 1998 through 2016 for the occurrence of incident AF. Participants were categorized as obese (body mass index ≥30) and nonobese (body mass index <30) and by NT-proBNP levels (using the median of 68.2 pg/mL as the cutoff). Over a median follow-up of 18.3 years, we identified 1806 incident cases of AF. Analysis using multivariable Cox regression models showed that obese participants with high NT-proBNP levels at visit 4 had a higher adjusted risk of incident AF (hazard ratio: 3.64; 95% CI, 3.15-4.22) compared with nonobese individuals with low NT-proBNP levels. The association of obesity with AF risk was not modified by NT-proBNP levels (P=0.46 for interaction). Increasing BNP among participants from 1990-1992 to 1996-1998 was associated with increased AF risk. After further adjustment for clinical risk factors and medications, results were similar. Conclusions Individuals who had both elevated body mass index and NT-proBNP and were free of clinically recognized heart failure were at higher risk of AF development. Those who experienced an increase in NT-proBNP levels between visits 2 and 4 were at higher risk of AF.

Background: Recent estimates suggest that dementia incidence is decreasing in the US possibly due to better management of cardiovascular disease (CVD) risk factors, but these studies lack repeated cross-sectional assessment among a representative US sample. Our objective was to assess temporal trends in cognitive performance in relation to CVD risk factors among older National Health and Nutrition Examination Survey (NHANES) participants. Methods: We used repeated cross-sectional assessment of 5711 participants ≥60 years of age from four NHANES cycles: 1999-2000, 2001-2002, 2011-2012 and 2013-2014. Cognitive function was assessed during each cycle with the Digit Symbol Substitution Test (DSST). We estimated mean DSST score at each cycle and annual trend in DSST before and after adjustment for age, sex, race/ethnicity, education, smoking status, blood pressure, glucose status and body mass index. Results: DSST scores was significantly higher for 2011-2012 (difference: 6.7, 95% CI 4.4 to 9.0) and 2013-2014 (difference: 6.2, 95% CI 4.0 to 8.5), but not 2001-2002 (difference: 2.3, 95% CI -0.01 to 4.6) as compared with 1999-2000 before adjustment. We observed a linear trend for higher annual DSST score before adjustment (DSST/year: 0.44, 95% CI 0.31 to 0.57) and after adjustment for age, sex, race/ethnicity, educational attainment and CVD risk factors (DSST/year: 0.17, 95% CI 0.08 to 0.26). Educational attainment was most strongly associated with the attenuation in the trend in cognitive function (77% of trend attenuation and 20% of variance in DSST). Conclusion: Cognitive function is improving over time for US adults aged ≥60 years. These improvements are strongly associated with greater educational attainment and irrespective of the changing US demographic and cardiovascular health profiles.

Objective: Oral anticoagulation (OAC) prescribed to AF patients for the prevention of cardioembolic complications likely has the added benefit of preventing venous thromboembolism (VTE). This study evaluated, among AF patients who are anticoagulated, whether type of OAC was associated with subsequent VTE risk. Methods: Non-valvular AF patients prescribed OACs between 2010 and September 2015 were identified via the MarketScan administrative claims databases. OACs included warfarin and direct OACs (DOACs: dabigatran, rivaroxaban, and apixaban). Incident VTE was defined by ICD-9-CM codes. Patients were matched on age, sex, CHA 2 DS 2 -VASc, and high-dimensional propensity scores. The final analysis included 117,912 AF patients. Results: In total, 1357 VTE events accrued over a mean follow-up of 484 days. In multivariable-adjusted, propensity score-matched Cox models, relative to new users of warfarin, risk of incident VTE was lower among new users of dabigatran [hazard ratio (95% confidence interval) = 0.55 (0.47–0.66)] and apixaban [0.51 (0.39–0.68)], but similar among new users of rivaroxaban [1.01 (0.87–1.19)]. In head-to-head DOAC comparisons, VTE risk was lower among users of dabigatran [0.48 (0.36–0.64)] and apixaban [0.61 (0.47–0.78)] vs rivaroxaban. Findings were mostly similar across patient sub-groups. Conclusions: In this large practice-based population of AF patients prescribed OACs for primary prevention of stroke and systemic embolization, subsequent risk of VTE was lowest among those prescribed apixaban and dabigatran, while risk was similar with prescriptions for warfarin and rivaroxaban. Among AF patients prescribed OACs, lowering the risk of VTE may be an additional benefit of apixaban and dabigatran, beyond the reduced bleeding risk observed in randomized clinical trials.

Essentials Ceruloplasmin (CP) is an acute-phase reactant and a potential biomarker of atherothrombotic risk. We assessed associations between CP and venous thromboembolism (VTE) risk in 9933 individuals. Higher circulating CP but not CP-related genes were associated with greater incident VTE rates. Circulating CP could be considered a non-causal biomarker of VTE risk in the community. Summary: Background Ceruloplasmin (CP) is an acute-phase reactant and a potential biomarker of atherothrombotic risk. We assessed the associations between CP, CP-associated genetic variants and incident venous thomboembolism (VTE) in the Atherosclerosis Risk in Communities study. Methods and results In an observational study, 9933 men and women aged 53–75 years without prevalent VTE were included in 1996–1998 and followed through 2011. Circulating CP was measured in stored blood samples obtained in 1996–1998. Polymorphisms rs11708215 and rs13072552, which have been previously associated with CP concentrations, were measured in 8439 participants. VTEs were identified from hospital discharge codes and validated by physician review of medical records and imaging reports. Over a mean of 10.5 years of follow-up, 376 cases of VTE were identified. The association between circulating CP, CP-associated polymorphisms and the incidence of VTE was estimated. After adjustment for traditional risk factors and biomarkers, higher concentrations of circulating CP were associated with greater incident VTE rates (hazard ratio 1.82, 95% confidence interval 1.12–2.95, comparing the 87.5–100th percentile with the bottom quartile). Both rs11708215 and rs13072552 were associated with CP concentrations but not with VTE risk. Conclusions Even though high CP concentrations were associated with an increased VTE risk, CP-associated genetic variants were not associated with a higher risk of VTE. Our results suggest that circulating CP concentrations may not be causally related to the risk of incident VTE.

It is unclear whether genetic markers interact with risk factors to influence atrial fibrillation (AF) risk. We performed genome-wide interaction analyses between genetic variants and age, sex, hypertension, and body mass index in the AFGen Consortium. Study-specific results were combined using meta-analysis (88,383 individuals of European descent, including 7,292 with AF). Variants with nominal interaction associations in the discovery analysis were tested for association in four independent studies (131,441 individuals, including 5,722 with AF). In the discovery analysis, the AF risk associated with the minor rs6817105 allele (at the PITX2 locus) was greater among subjects ≤ 65 years of age than among those > 65 years (interaction p-value = 4.0 × 10(-5)). The interaction p-value exceeded genome-wide significance in combined discovery and replication analyses (interaction p-value = 1.7 × 10(-8)). We observed one genome-wide significant interaction with body mass index and several suggestive interactions with age, sex, and body mass index in the discovery analysis. However, none was replicated in the independent sample. Our findings suggest that the pathogenesis of AF may differ according to age in individuals of European descent, but we did not observe evidence of statistically significant genetic interactions with sex, body mass index, or hypertension on AF risk.