Research Priorities in Atrial Fibrillation Screening: A Report From a National Heart, Lung, and Blood Institute Virtual Workshop.

Clinically recognized atrial fibrillation (AF) is associated with higher risk of complications, including ischemic stroke, cognitive decline, heart failure, myocardial infarction, and death. It is increasingly recognized that AF frequently is undetected until complications such as stroke or heart failure occur. Hence, the public and clinicians have an intense interest in detecting AF earlier. However, the most appropriate strategies to detect undiagnosed AF (sometimes referred to as subclinical AF) and the prognostic and therapeutic implications of AF detected by screening are uncertain. Our report summarizes the National Heart, Lung, and Blood Institute's virtual workshop focused on identifying key research priorities related to AF screening. Global experts reviewed major knowledge gaps and identified critical research priorities in the following areas: (1) role of opportunistic screening; (2) AF as a risk factor, risk marker, or both; (3) relationship between AF burden detected with long-term monitoring and outcomes/treatments; (4) designs of potential randomized trials of systematic AF screening with clinically relevant outcomes; and (5) role of AF screening after ischemic stroke. Our report aims to inform and catalyze AF screening research that will advance innovative, resource-efficient, and clinically relevant studies in diverse populations to improve the diagnosis, management, and prognosis of patients with undiagnosed AF.

Association of Differential Leukocyte Count With Incident Abdominal Aortic Aneurysm Over 22.5 Years: The ARIC Study.

OBJECTIVE: Leukocytes contribute to the development of abdominal aortic aneurysm (AAA). We evaluated whether associations of differential leukocyte counts with AAA persist after accounting for traditional risk factors of AAA. APPROACH AND RESULTS: Among 11 217 adults from the Atherosclerosis Risk in Communities Study, we evaluated associations of differential leukocyte counts at baseline (1987­1989) with incident AAAs over a median follow-up of 22.5 years, using Cox proportional hazards regression. Each differential leukocyte count was categorized into 5 groups­below normal, tertiles within the normal range, and above normal, with the first tertile serving as the referent. We identified 377 incident AAAs through 2011, using hospital discharge diagnoses, linked Medicare records, or death certificates. At baseline, higher neutrophil, monocyte, and eosinophil counts were associated with higher risk of AAA, independent of smoking, other differential leukocyte counts, and other traditional risk factors. The association with incident AAA was the strongest for above normal neutrophil count, with an adjusted hazard ratio (95% CI) of 2.17 (1.29­3.64). Below normal neutrophil, lymphocyte, eosinophil and basophil counts were associated with higher risk of AAA with adjusted hazard ratio (95% CI) between 1.86 (1.04­3.35) and 1.62 (1.10­2.39). CONCLUSIONS: Higher neutrophil, monocyte, and eosinophil counts in midlife are associated with higher risk of AAA, even after accounting for traditional risk factors such as smoking, obesity, and atherosclerosis. This suggests the need to identify nontraditional risk factors and treatment strategies to mitigate the residual risk of AAA conferred by midlife inflammation. Whether immunosuppression is associated with higher risk of AAA needs further investigation.

Association of physical activity with the incidence of atrial fibrillation in persons > 65 years old: the Atherosclerosis Risk in Communities (ARIC) study.

AIMS: To evaluate the association of physical activity (PA) with atrial fibrillation (AF) incidence in an elderly population. METHODS: We studied 5166 participants of the Atherosclerosis Risk in Communities cohort examined in 2011-2013 free of AF. Self-reported PA was evaluated with a validated questionnaire. Weekly minutes of leisure-time moderate to vigorous physical activity (MVPA) were calculated and categorized using the 2018 Physical Activity Guidelines for Americans (no activity [0 min/week], low [> 0- < 150 min/week], adequate [150- < 300 min/week], high [≥ 300 min/week]). Incident AF through 2019 was ascertained from hospital discharges and death certificates. Cox models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for AF by levels of physical activity adjusting for potential confounders. RESULTS: The mean (SD) age for the sample was 75 (5) years (59% female, 22% Black). During a mean (SD) follow-up time of 6.3 (2.0) years, 703 AF events were identified. The association of MVPA with AF incidence showed a U-shaped relationship. Compared to those not engaging in MVPA, individuals with low MVPA had a 23% lower hazard of AF (HR = 0.77; 95% CI 0.61, 0.96), while those with adequate MVPA had a 14% lower hazard (HR 0.86; 95% CI 0.69, 1.06). High levels of MVPA were not associated with AF risk (HR 0.97; 95% CI 0.78, 1.20). CONCLUSION: This study suggests that being involved in low to moderate levels of MVPA is associated with lower AF risk, with no evidence of increased risk of AF in those with higher levels of MVPA.

Activities-specific performance frequency can accurately detect fallers in elderly populations: an alternative method for quantifying activity restrictions.

BACKGROUND: The high prevalence of falling among older adults constitutes a major public and clinical health concern. Many elderly persons may develop activities-specific restriction due to the risk of falling. This highlights the need for relevant evaluative tools. METHODS: This cross-sectional study used activities-specific performance frequency indicators to quantify activity restrictions in elderly participants, with all measures based on items from the Activities-Specific Balance Confidence (ABC) scale. Specifically, we tested for correlations between activities-specific performance frequency and balance confidence, functional balance/mobility, and fall history. There were 88 elderly participants, including 28 with stroke, 30 with Parkinson's disease, and 30 with no neurological diseases. In addition to their activities-specific performance frequency measures, we collected a series of demographic and health-related characteristics from each participant. We analyzed between-group differences in activities-specific performance frequency and other demographic and health-related characteristics via the one-way analysis of variance and Kruskal-Wallis test. Next, we used the Spearman's rank correlation test and binary logistic regression to investigate the correlations between activities-specific performance frequency and demographic/other health-related characteristics. RESULTS: There were significant group differences in performance frequency for all ABC activity items except for walking around the house, average ABC scores, and functional balance/mobility among normal older adults, participants with strokes and those with Parkinson's disease. Activities-specific performance frequency showed stronger correlations with activities-relevant functional mobility (r=0.250-0.713 for 15 items with significant correlations, 13 activity items with r≧0.4) than with balance confidence (r=0.279-0.668 for 13 items with significant correlations, 10 activity items with r≧0.4). The performance frequency of walking in crowds/bumped was the most sensitive measure for predicting fallers (odd ratio=3.310, p<0.05). CONCLUSIONS: This study proposed and validated the usage of activities-specific performance frequency as an alternative method for quantifying activity restrictions among older adults.

Lifestyle and Risk Factor Modification for Reduction of Atrial Fibrillation: A Scientific Statement From the American Heart Association.

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is associated with substantial morbidity, mortality, and healthcare use. Great strides have been made in stroke prevention and rhythm control strategies, yet reducing the incidence of AF has been slowed by the increasing incidence and prevalence of AF risk factors, including obesity, physical inactivity, sleep apnea, diabetes mellitus, hypertension, and other modifiable lifestyle-related factors. Fortunately, many of these AF drivers are potentially reversible, and emerging evidence supports that addressing these modifiable risks may be effective for primary and secondary AF prevention. A structured, protocol-driven multidisciplinary approach to integrate lifestyle and risk factor management as an integral part of AF management may help in the prevention and treatment of AF. However, this aspect of AF management is currently underrecognized, underused, and understudied. The purpose of this American Heart Association scientific statement is to review the association of modifiable risk factors with AF and the effects of risk factor intervention. Implementation strategies, care pathways, and educational links for achieving impactful weight reduction, increased physical activity, and risk factor modification are included. Implications for clinical practice, gaps in knowledge, and future directions for the research community are highlighted.

Periodontal Disease, Atrial Fibrillation and Stroke.

BACKGROUND: We recently described the association between periodontal disease (PD) and stroke risk. PURPOSE: The purpose of this study was to test the association between PD, dental care utilization and incident atrial fibrillation (AF), as well as AF as a mediator to PD- stroke association. METHODS: In dental cohort of the Atherosclerosis Risk in Communities Study (ARIC), participants without prior AF underwent full-mouth periodontal measurements. PD was defined on an ordinal scale as healthy (referent), mild, moderate and severe. In ARIC main cohort, participants were classified as regular or episodic dental care users. These patients were followed for AF, over 17 years. Cox proportional hazards models adjusted for AF risk factors were used to study relationships between PD severity, dental care utilization and AF. Mediation analysis was used to test if AF mediated the PD- stroke association. RESULTS: In dental ARIC cohort, 5,958 were assessed without prior AF, 754 were found to have AF. Severe PD was associated with AF on both univariable (crude HR, 1.54; 95% CI, 1.26-1.87) and multivariable (adjusted HR, 1.31, 95% CI, 1.06-1.62) analyses. Mediation analysis suggested AF mediates the association between PD and stroke. In the main ARIC cohort, 9,666 participants without prior AF were assessed for dental care use, 1558 were found to have AF. Compared with episodic users, regular users had a lower risk for AF on univariable (crude HR, 0.82, 95% CI, 0.74-0.90) and multivariable (adjusted HR, 0.88, 95% CI, 0.78-0.99) analyses. CONCLUSIONS: PD is associated with AF. The association may explain the PD-stroke risk. Regular users had a lower risk of incident AF compared with episodic users.

Proton Pump Inhibitor Use, Hypomagnesemia and Risk of Cardiovascular Diseases: The Atherosclerosis Risk in Communities (ARIC) Study.

GOALS: The goal of this study was to evaluate whether proton pump inhibitor (PPI) use is cross-sectionally associated with hypomagnesemia and whether hypomagnesemia mediates the prospective association between PPIs and cardiovascular disease (CVD) risk. BACKGROUND: Use of PPIs has been associated with hypomagnesemia, primarily in case reports or within insurance databases. Both PPI use and low serum magnesium (Mg) have been associated with modestly higher CVD risk. Yet, the interrelation between PPI use and Mg in relation to CVD risk is unclear. STUDY: The 4436 Atherosclerosis Risk in Communities participants without prevalent CVD at visit 5 (baseline, 2011-2013) were included. Multivariable relative risk regression was used for cross-sectional analyses between PPI and hypomagnesemia prevalence (≤0.75 mmol/L). Incident CVD (defined by atrial fibrillation, coronary heart disease, CVD mortality, heart failure, stroke) was identified through 2017. Multivariable Cox regression was used to examine the PPI-CVD association. RESULTS: Participants were mean±SD aged 75±5 years; 63% were women, 23% Black, and 24% were PPI users. PPI users had 1.24-fold (95% confidence interval: 1.08-1.44) higher prevalence of hypomagnesemia than nonusers. Over a median 5 years of follow-up, 684 incident CVD events occurred. PPI users had higher CVD risk [hazard ratio (95% confidence interval) 1.31 (1.10-1.57)] than nonusers. The effect estimate was largely unchanged when hypomagnesemia was added to the model as a potential mediator. CONCLUSIONS: In this elderly community-based study, PPI users had a higher prevalence of hypomagnesemia than in nonusers. PPI users also had higher CVD risk than nonusers; however, it appears unlikely that hypomagnesemia explains associations of PPIs with CVD risk.

Sex differences in treatment strategy and adverse outcomes among patients 75 and older with atrial fibrillation in the MarketScan database.

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 and 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.

Association of arterial stiffness with incident atrial fibrillation: a cohort study.

BACKGROUND: Stiff arteries increase left ventricular (LV) end-systolic workload, leading over time to left atrial and ventricular remodeling, and providing the substrate for atrial fibrillation (AF) development. We investigated if carotid femoral pulse wave velocity (cfPWV), a measure of central arterial stiffness, is associated with incident AF. METHODS: In 2011-2013, cfPWV was measured in 3882 participants of the Atherosclerosis Risk in Communities Cohort Study (ARIC) without prevalent AF. Participants were followed through 2017 for the incidence of AF. Individuals were categorized in cfPWV quartiles based on visit measurements. Multivariable Cox regression models were used to evaluate the association of cfPWV with incident AF. RESULTS: Mean age was 75 years (SD 5), 60% were female and 20% were African American. Over a median follow-up of 5.5 years we identified 331 incident cases of AF. cfPWV demonstrated U-shaped associations with AF risk. In models adjusted for age, race, center, sex, education levels, and hemodynamic and clinical factors, hazard ratios (HR) of AF for participants in the first, third and fourth quartiles were 1.49 (95% CI 1.06, 2.10), 1.59 (1.14, 2.10), and 1.56(1.10, 2.19), respectively, compared to those in the second quartile. CONCLUSION: Among community-dwelling older adults, low and high central arterial stiffness is associated with AF risk.

Establishing content validity for a composite activities-specific risk of falls scale:linkage between fear of falling and physical activity.

BACKGROUND: Fear of falling (FoF) and physical activity (PA) are important psychological and behavioral factors associated with falls. No instrument quantifies the link between these two factors to evaluate the risk of falls. We aimed to design a scale linking FoF with PA (Composite Activities-specific Risk of Falls Scale, CARFS) for people with various disability levels. METHODS: First, we designed a questionnaire comprising 40 balance-related activities from the International Classification of Functioning, Disability, and Health (ICF) for a pilot survey. Second, participants were interviewed about their activities-specific FoF degree and PA frequency. The participants comprised 30 community-dwelling older adults, hospitalized patients with strokes, and those with spinal cord injuries, each with different disability levels. Third, the content validity of the items was evaluated twice by 12 experienced rehabilitation professionals: one based on experience and the other on the survey responses. Items with a higher than moderate relevance in both evaluations were included in the CARFS. The panel of professionals discussed and voted on the contribution of FoF and PA on the CARF score. Finally, the scale sensitivity in distinguishing disability levels was analyzed to evaluate the population suitability to the CARFS. RESULTS: The CARFS included 14 activities. A five-point Likert scale was used to quantify degree of FoF (A) and frequency of PA (B). The CARF score (C), which was determined using the eq. C = A+(4-B) + A × B/2, reflected sensitivity to disability levels in most items. CONCLUSIONS: The CARFS has strong content validity for measuring risk of falls in relation to the FoF and PA of people with various disability levels. It has a potential to provide a guide for designing individualized exercise- and behavior-focused fall prevention programs and enable the precise trtrun 0acking of program effectiveness as a multidimensional outcome measure.

Subclinical and Device-Detected Atrial Fibrillation: Pondering the Knowledge Gap: A Scientific Statement From the American Heart Association.

The widespread use of cardiac implantable electronic devices and wearable monitors has led to the detection of subclinical atrial fibrillation in a substantial proportion of patients. There is evidence that these asymptomatic arrhythmias are associated with increased risk of stroke. Thus, detection of subclinical atrial fibrillation may offer an opportunity to reduce stroke risk by initiating anticoagulation. However, it is unknown whether long-term anticoagulation is warranted and in what populations. This scientific statement explores the existing data on the prevalence, clinical significance, and management of subclinical atrial fibrillation and identifies current gaps in knowledge and areas of controversy and consensus.

Refining Prediction of Atrial Fibrillation-Related Stroke Using the P2-CHA2DS2-VASc Score.

BACKGROUND: In people with atrial fibrillation (AF), periods of sinus rhythm present an opportunity to detect prothrombotic atrial remodeling through measurement of P-wave indices (PWIs)-prolonged P-wave duration, abnormal P-wave axis, advanced interatrial block, and abnormal P-wave terminal force in lead V1. We hypothesized that the addition of PWIs to the CHA2DS2-VASc score would improve its ability to predict AF-related ischemic stroke. METHODS: We included 2229 participants from the ARIC study (Atherosclerosis Risk in Communities) and 700 participants from MESA (Multi-Ethnic Study of Atherosclerosis) with incident AF who were not on anticoagulants within 1 year of AF diagnosis. PWIs were obtained from study visit ECGs before development of AF. AF was ascertained using study visit ECGs and hospital records. Ischemic stroke cases were based on physician adjudication of hospital records. We used Cox proportional hazards models to estimate hazard ratios and 95% CIs of PWIs for ischemic stroke. Improvement in 1-year stroke prediction was assessed by C-statistic, categorical net reclassification improvement, and relative integrated discrimination improvement. RESULTS: Abnormal P-wave axis was the only PWI associated with increased ischemic stroke risk (hazard ratio, 1.84; 95% CI, 1.33-2.55) independent of CHA2DS2-VASc variables, and that resulted in meaningful improvement in stroke prediction. The ß estimate was approximately twice that of the CHA2DS2-VASc variables, and thus abnormal P-wave axis was assigned 2 points to create the P2-CHA2DS2-VASc score. This improved the C-statistic (95% CI) from 0.60 (0.51-0.69) to 0.67 (0.60-0.75) in ARIC and 0.68 (0.52-0.84) to 0.75 (0.60-0.91) in MESA (validation cohort). In ARIC and MESA, the categorical net reclassification improvements (95% CI) were 0.25 (0.13-0.39) and 0.51 (0.18-0.86), respectively, and the relative integrated discrimination improvement (95% CI) were 1.19 (0.96-1.44) and 0.82 (0.36-1.39), respectively. CONCLUSIONS: Abnormal P-wave axis-an ECG correlate of left atrial abnormality- improves ischemic stroke prediction in AF. Compared with CHA2DS2-VASc, the P2-CHA2DS2-VASc is a better prediction tool for AF-related ischemic stroke.

Circulating electrolytes and the prevalence of atrial fibrillation and supraventricular ectopy: The Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND AND AIMS: Evaluating associations of circulating electrolytes with atrial fibrillation (AF) and burden of supraventricular arrhythmias can give insights into arrhythmia pathogenesis. METHODS AND RESULTS: We conducted a cross-sectional analysis of 6398 participants of the Atherosclerosis Risk in Communities (ARIC) study, ages 71-90, with data on serum electrolytes (magnesium, calcium, potassium, phosphorus, chloride, sodium). Prevalence of AF was determined from electrocardiograms and history of AF hospitalizations. A subset of 317 participants also underwent electrocardiographic recordings for up to 14 days using the Zio® patch. Burden of other supraventricular arrhythmias [premature atrial contractions (PACs), supraventricular tachycardia] was determined with the Zio® patch. We used logistic and linear regression adjusting for potential confounders to determine associations of electrolytes with arrhythmia prevalence and burden. Among 6394 eligible participants, 614 (10%) had AF. Participants in the top quintiles of magnesium [odds ratio (OR) 0.82, 95% confidence interval (CI) 0.62, 1.08], potassium (OR 0.82, 95%CI 0.68, 1.00), and phosphorus (OR 0.73, 95%CI 0.59, 0.89) had lower AF prevalence compared to those in the bottom quintiles. No clear association was found for circulating chloride, calcium or sodium. Higher concentrations of circulating calcium were associated with lower prevalence of PACs in the 12-lead electrocardiogram, while higher concentrations of potassium, chloride and sodium were associated with higher PAC prevalence. Circulating electrolytes were not significantly associated with burden of PACs or supraventricular tachycardia among 317 participants with extended electrocardiographic monitoring. CONCLUSION: Concentrations of circulating electrolytes present complex associations with selected supraventricular arrhythmias. Future studies should evaluate underlying mechanisms.

Association between excessive daytime sleepiness and measures of supraventricular arrhythmia burden: evidence from the Atherosclerosis Risk in Communities (ARIC) study.

PURPOSE: Excessive daytime sleepiness is a common sleep complaint among older adults. Assessment of excessive daytime sleepiness is used to screen for obstructive sleep apnea, which may be linked to atrial fibrillation (AF) and other sustained arrhythmias. Using data from the Atherosclerosis Risk in Communities (ARIC) Study cohort, we examined the association of excessive daytime sleepiness with measures of arrhythmia burden derived from a continuous ECG recording device in a community-based sample of older adults. METHODS: Participating older adults (N = 2306, mean age: 78.9 ± 4.5 years, 57.8% female) wore a Zio® XT Patch for 14 days. Excessive daytime sleepiness was assessed with the Epworth Sleepiness Scale. Measures of AF and supraventricular arrhythmia burden were derived from the Zio® XT Patch. Multiple adjusted logistic, multinomial, and linear regression models were used to assess associations of excessive daytime sleepiness with AF, AF burden, and supraventricular arrhythmia burden. RESULTS: Approximately 18% of the sample had excessive daytime sleepiness, and 8.5% had AF. After adjustment, excessive daytime sleepiness was not significantly associated with AF (odds ratio (OR), 1.20; Confidence Interval (CI), 0.81-1.75), continuous AF burden (OR, 1.36; CI, 0.85-2.16), or measures of supraventricular arrhythmia burden (SVE burden: ß 0.01; 95% CI, -0.09-0.11; SVT burden: ß 0.02; 95% CI, -0.04-0.08). CONCLUSION: In this community-based sample of older adults, excessive daytime sleepiness was not associated with measures of arrhythmia burden. Future studies with objective measures of sleep are needed to further examine the role of sleep in the development and progression of arrhythmia burden.

Diurnal circadian variations in paroxysmal atrial fibrillation: The atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Paroxysmal atrial fibrillation (AF) is challenging to diagnose due to its intermittent nature. Circadian rhythmicity has been reported for cardiovascular events such as myocardial infarction; whether diurnal variation exists for paroxysmal AF is less known. We characterized the temporal pattern of AF initiation in the Atherosclerosis Risk in Communities (ARIC) study, a prospective community-based cohort study. METHODS: We included 74 ARIC study participants with paroxysmal AF detected by the Zio XT Patch at ARIC Visit 6 in 2016-17. We divided each participant's 2-week continuous monitoring data into 3-h intervals and summed the number of AF episodes in each interval. We performed Poisson regression using generalized estimating equations to estimate the effect of time of day on the number of AF episodes. RESULTS: Compared to the reference interval of time 00:00-02:59, the time intervals 12:00-14:59, 15:00-17:59, and 18:00-20:59 had significantly higher frequency of AF initiation. Rate ratios (95% CI) for mean number of episodes in these three intervals were 1.91 (1.11, 2.92), 2.54 (1.42, 4.53), and 1.99 (1.19, 3.25) respectively. Furthermore, we found no significant association between duration of episode and time of day. CONCLUSION: There is diurnal variation in the initiation of AF episodes, with a peak in frequency in the late afternoon. Our finding is consistent with sympathetically driven AF. Pulse palpation or obtaining an electrocardiogram in the late afternoon may produce the highest diagnostic yield for AF.

Electrocardiographic left atrial abnormality in patients presenting with ischemic stroke.

BACKGROUND: P wave indices represent electrocardiographic marker of left atrial pathology. We hypothesized that P wave would be more abnormal in patients presenting with ischemic stroke than a comparable group without ischemic stroke. METHODS: We compared P wave terminal force in V1 (PTFV1) between patients admitted with ischemic stroke (case) and patients followed in cardiology clinic (control) at a single medical center. Using logistic regression models, we tested for an association between abnormal PTFV1 (> 4000 µV ms) and ischemic stroke. We also defined several optimal cut-off values of PTFV1 using a LOESS plot and estimated odds ratio of ischemic stroke when moving from one cut-point level to the next higher-level. RESULTS: A total of 297 patients (case 147, control 150) were included. PTFV1 was higher in patients with vs. those without ischemic stroke (median 4620 vs 3994 µV ms; p=0.006). PTFV1 was similar between cardioembolic/cryptogenic and other stroke subtypes. In multivariable analyses adjusting for sex, obesity, age, and hypertension, the association between abnormal PTFV1 and ischemic stroke ceased to be significant (OR 1.53 [0.95, 2.50], p=0.083). Increase to the next cutoff level of PTFV1 (900, 2000, 3000, 4000, 5000, and 6000 µV ms) was associated with 18% increase in odds of having ischemic stroke (vs. no ischemic stroke) (OR 1.18 [1.02, 1.36], p=0.026). CONCLUSION: Patients presenting with acute ischemic stroke are more likely to have abnormal PTFV1. These findings from a real-world clinical setting support the results of cohort studies that left atrial pathology manifested as abnormal PTFV1 is associated with ischemic stroke.

Atrial Fibrillation Burden: Moving Beyond Atrial Fibrillation as a Binary Entity: A Scientific Statement From the American Heart Association.

Our understanding of the risk factors and complications of atrial fibrillation (AF) is based mostly on studies that have evaluated AF in a binary fashion (present or absent) and have not investigated AF burden. This scientific statement discusses the published literature and knowledge gaps related to methods of defining and measuring AF burden, the relationship of AF burden to cardiovascular and neurological outcomes, and the effect of lifestyle and risk factor modification on AF burden. Many studies examine outcomes by AF burden classified by AF type (paroxysmal versus nonparoxysmal); however, quantitatively, AF burden can be defined by longest duration, number of AF episodes during a monitoring period, and the proportion of time an individual is in AF during a monitoring period (expressed as a percentage). Current guidelines make identical recommendations for anticoagulation regardless of AF pattern or burden; however, a review of recent evidence suggests that higher AF burden is associated with higher risk of stroke. It is unclear whether the risk increases continuously or whether a threshold exists; if a threshold exists, it has not been defined. Higher burden of AF is also associated with higher prevalence and incidence of heart failure and higher risk of mortality, but not necessarily lower quality of life. A structured and comprehensive risk factor management program targeting risk factors, weight loss, and maintenance of a healthy weight appears to be effective in reducing AF burden. Despite this growing understanding of AF burden, research is needed into validation of definitions and measures of AF burden, determination of the threshold of AF burden that results in an increased risk of stroke that warrants anticoagulation, and discovery of the mechanisms underlying the weak temporal correlations of AF and stroke. Moreover, developments in monitoring technologies will likely change the landscape of long-term AF monitoring and could allow better definition of the significance of changes in AF burden over time.

CHA2DS2-VASc Score and Stroke Prediction in Atrial Fibrillation in Whites, Blacks, and Hispanics.

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.

Metabolic Syndrome and Risk of Ischemic Stroke in Atrial Fibrillation: ARIC Study.

Background and Purpose- Metabolic syndrome (MetS), a prothrombotic state, is associated with an increased risk of atrial fibrillation (AF) and stroke. The CHA2DS2-VASc score does not account for the MetS components of prehypertension, prediabetes mellitus, abdominal obesity, elevated triglycerides, and low HDL (high-density lipoprotein). Data are limited on the association of MetS with stroke in AF, independent of CHA2DS2-VASc variables. Our aim was to identify MetS components associated with ischemic stroke in participants with AF in the ARIC study (Atherosclerosis Risk in Communities). Methods- We included 1172 participants with incident AF within 5 years of measurement of MetS components. MetS was defined by ATP criteria and International Diabetes Federation criteria. Incident ischemic stroke was physician adjudicated. Multivariable Cox proportional hazards regression was used to assess the association of MetS components with stroke. Results- After a median follow-up of 14.8 years, there were 113 ischemic stroke cases. Of the individual MetS components, low HDL was borderline associated with increased stroke risk (hazard ratio, 1.48 [95% CI, 0.99-2.21]) after adjustment for CHA2DS2-VASc variables while the remaining MetS variables were not associated with stroke risk. The presence of ≥3 components of MetS was not significantly associated with ischemic stroke after adjustment for CHA2DS2-VASc variables (hazard ratio, 1.38 [95% CI, 0.91-2.11]). The risk of stroke increased by 13% for each additional component of MetS; however, this association was borderline significant (hazard ratio, 1.13 [95% CI, 0.99-1.28]). Conclusions- The presence of MetS was not significantly associated with ischemic stroke after adjustment for CHA2DS2-VASc variables. Consideration of MetS is unlikely to improve stroke prediction in AF.

Association of Atrial Fibrillation With White Matter Disease.

Background and Purpose- Evidence suggests that atrial fibrillation (AF) is associated with increased risk of cognitive decline and dementia, even in the absence of stroke. White matter disease (WMD) is a potential mechanism linking AF to cognitive impairment. In this study, we explored the association between prevalent AF and WMD. Methods- We performed a cross-sectional analysis of participants attending the ARIC-NCS (Atherosclerosis Risk in Communities-Neurocognitive Study) in 2011 to 2013 who underwent brain magnetic resonance imaging. AF was ascertained from study visit electrocardiograms or prior hospitalization codes. Extent of WMD was defined by measures of white matter (WM) microstructural integrity and WM hyperintensity volume. Multivariable linear regression models were used to assess the association between AF and WMD. Results- Among 1899 participants (mean age, 76 years; 28% black; 60% women), 133 (7%) had prevalent AF. After multivariable adjustment, differences between participants with and without AF were -0.001 (95% CI, -0.006 to 0.004) for global WM fractional anisotropy, 0.031×10-4 mm2/s (95% CI, -0.075 to 0.137) for global WM mean diffusivity, and 0.08 mm3 (95% CI, -0.14 to 0.30) for WM hyperintensity volume. Conclusions- The results suggest that there is no association between prevalent AF and WMD.