Prevalence and Characteristics of Subclinical Atrial Fibrillation in a Community-Dwelling Elderly Population: The ARIC Study

Association of Left Atrial Function With Incident Chronic Kidney Disease in Older Adults

Objective

To examine the association of left atrial (LA) function with incident chronic kidney disease (CKD) and assess the clinical utility of adding LA function to a CKD risk prediction equation.

Patients and Methods

We included 4002 Atherosclerosis Risk in Communities study participants without prevalent CKD (mean ± SD age, 75±5 years; 58% female, 18% Black). Left atrial function (reservoir, conduit, and contractile strain) was evaluated by 2D-echocardiograms on 2011 to 2013. Chronic kidney disease was defined as greater than 25% decline in estimated glomerular filtration rate of less than 60 mL/min/1.73 m2, end-stage kidney disease, or hospital records. Cox proportional hazards models were used. Risk prediction and decision curve analyses evaluated 5-year CKD risk by diabetes status.

Results

Median follow-up was 7.2 years, and 598 participants developed incident CKD. Incidence rate for CKD was 2.29 per 100 person-years. After multivariable adjustments, the lowest quintile of LA reservoir, conduit, and contractile strain (vs highest quintile) had a higher risk of CKD (hazard ratios [95% CIs]: 1.94 [1.42-2.64], 1.62 [1.19-2.20], and 1.49 [1.12-1.99]). Adding LA reservoir strain to the CKD risk prediction equation variables increased the C-index by 0.026 (95% CI: 0.005-0.051) and 0.031 (95% CI: 0.006-0.058) in participants without and with diabetes, respectively. Decision curve analysis found the model with LA reservoir strain had a higher net benefit than the model with CKD risk prediction equation variables alone.

Conclusion

Lower LA function is independently associated with incident CKD. Adding LA function to the CKD risk prediction enhances prediction and yields a higher clinical net benefit. These findings suggest that impaired LA function may be a novel risk factor for CKD.

Advancing Wearable Biosensors for Congenital Heart Disease: Patient and Clinician Perspectives: A Science Advisory From the American Heart Association

Wearable biosensors (wearables) enable continual, noninvasive physiologic and behavioral monitoring at home for those with pediatric or congenital heart disease. Wearables allow patients to access their personal data and monitor their health. Despite substantial technologic advances in recent years, issues with hardware design, data analysis, and integration into the clinical workflow prevent wearables from reaching their potential in high-risk congenital heart disease populations. This science advisory reviews the use of wearables in patients with congenital heart disease, how to improve these technologies for clinicians and patients, and ethical and regulatory considerations. Challenges related to the use of wearables are common to every clinical setting, but specific topics for consideration in congenital heart disease are highlighted.

Validation of a Zio XT Patch Accelerometer for the Objective Assessment of Physical Activity in the Atherosclerosis Risk in Communities (ARIC) Study

BACKGROUND

Combination devices to monitor heart rate/rhythms and physical activity are becoming increasingly popular in research and clinical settings. The Zio XT Patch (iRhythm Technologies, San Francisco, CA, USA) is US Food and Drug Administration (FDA)-approved for monitoring heart rhythms, but the validity of its accelerometer for assessing physical activity is unknown.

OBJECTIVE

To validate the accelerometer in the Zio XT Patch for measuring physical activity against the widely-used ActiGraph GT3X.

METHODS

The Zio XT and ActiGraph wGT3X-BT (Actigraph, Pensacola, FL, USA) were worn simultaneously in two separately-funded ancillary studies to Visit 6 of the Atherosclerosis Risk in Communities (ARIC) Study (2016-2017). Zio XT was worn on the chest and ActiGraph was worn on the hip. Raw accelerometer data were summarized using mean absolute deviation (MAD) for six different epoch lengths (1-min, 5-min, 10-min, 30-min, 1-h, and 2-h). Participants who had ≥3 days of at least 10 h of valid data between 7 a.m-11 p.m were included. Agreement of epoch-level MAD between the two devices was evaluated using correlation and mean squared error (MSE).

RESULTS

Among 257 participants (average age: 78.5 ± 4.7 years; 59.1% female), there were strong correlations between MAD values from Zio XT and ActiGraph (average r: 1-min: 0.66, 5-min: 0.90, 10-min: 0.93, 30-min: 0.93, 1-h: 0.89, 2-h: 0.82), with relatively low error values (Average MSE × 106: 1-min: 349.37 g, 5-min: 86.25 g, 10-min: 56.80 g, 30-min: 45.46 g, 1-h: 52.56 g, 2-h: 54.58 g).

CONCLUSIONS

These findings suggest that Zio XT accelerometry is valid for measuring duration, frequency, and intensity of physical activity within time epochs of 5-min to 2-h.

Stages of Valvular Heart Disease Among Older Adults in the Community: The Atherosclerosis Risk in Communities Study

BACKGROUND

Limited data exist on American College of Cardiology/American Heart Association valvular heart disease (VHD) stage prevalence, progression, and association with incident cardiovascular diseases in late life.

METHODS

Participants in the ARIC study (Atherosclerosis Risk in Communities), a prospective community-based cohort study, underwent protocol echocardiography at ARIC visits 5 (2011-2013) and 7 (2018-2019), and their aortic stenosis, aortic regurgitation, mitral stenosis, and mitral regurgitation stage were defined according to American College of Cardiology/American Heart Association guidelines. The overall VHD stage prevalence at visit 5 was measured. The associations between VHD stages and incident adjudicated death, heart failure, coronary heart disease, stroke, and atrial fibrillation were assessed with Cox proportional hazard models adjusted for age, sex, race, hypertension, diabetes, prior myocardial infarction, heart failure, body mass index, study center, systolic blood pressure, estimated glomerular filtration rate, and low-density lipoprotein at visit 5. Longitudinal changes in VHD stage prevalence over ≈6 years were estimated with inverse probability of attrition weights to account for participant attrition.

RESULTS

Among 6118 ARIC participants, the mean±SD age was 76±5 years, 42% were male, and 22% reported Black race. Stage A VHD was present in 39%, stage B in 17%, and stage C/D in 1.1%;, 0.7% had previously undergone valve replacement or repair. A graded association was observed between stage A, B, and C/D VHD and risk of all-cause mortality, incident heart failure, incident atrial fibrillation, and incident coronary heart disease, but not incident stroke. Similar findings were observed for stages of each valvular lesion individually. During the 6.6 years (interquartile range, 6.1-7.0 years) between visits 5 and 7 (mean age, 81±4 years), the prevalence of freedom from VHD stage decreased from 43% to 24%, whereas the prevalence of stage C/D VHD increased from 1% to 7%.

CONCLUSIONS

Subclinical VHD is common in older adults, with 39% at risk (stage A) and 17% with progressive VHD (stage B), and is independently associated with risk of incident cardiovascular events. VHD stages progress over 6 years in late life, with a several-fold increase in prevalence of severe VHD (stage C/D), highlighting the public health importance of interventions to mitigate VHD progression.

Left Atrial Mechanical Dysfunction and the Risk for Ischemic Stroke in People Without Prevalent Atrial Fibrillation or Stroke : A Prospective Cohort Study

BACKGROUND

Atrial myopathy-characterized by changes in left atrial function and size-may precede and promote atrial fibrillation (AF) and cardiac thromboembolism. In people without prior AF or stroke, whether analysis of left atrial function and size can improve ischemic stroke prediction is unknown.

OBJECTIVE

To evaluate the association of echocardiographic left atrial function (reservoir, conduit, and contractile strain) and left atrial size (left atrial volume index) with ischemic stroke and determine whether these measures can improve the stroke prediction achieved by CHA2DS2-VASc score variables.

DESIGN

Prospective cohort study.

SETTING

ARIC (Atherosclerosis Risk in Communities) study.

PARTICIPANTS

4917 ARIC participants without prevalent stroke or AF.

MEASUREMENTS

Ischemic stroke events (2011 to 2019) were adjudicated by physicians. Left atrial strain was measured using speckle-tracking echocardiography.

RESULTS

Over 5 years, the cumulative incidences of ischemic stroke in the lowest quintiles of left atrial reservoir, conduit, and contractile strain were 2.99% (95% CI, 1.89% to 4.09%), 3.18% (CI, 2.14% to 4.22%), and 2.15% (CI, 1.09% to 3.21%), respectively, and that of severe left atrial enlargement was 1.99% (CI, 0.23% to 3.75%). On the basis of the Akaike information criterion, left atrial reservoir strain plus CHA2DS2-VASc variables was the best predictive model. With the addition of left atrial reservoir strain to CHA2DS2-VASc variables, 11.6% of the 112 participants with stroke after 5 years were reclassified to higher risk categories and 1.8% to lower risk categories. Among the 4805 participants who did not develop stroke, 12.2% were reclassified to lower and 12.7% to higher risk categories. Decision curve analysis showed a predicted net benefit of 1.34 per 1000 people at a 5-year risk threshold of 5%.

LIMITATION

Underascertainment of subclinical AF.

CONCLUSION

In people without prior AF or stroke, when added to CHA2DS2-VASc variables, left atrial reservoir strain improves stroke prediction and yields a predicted net benefit, as shown by decision curve analysis.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute of the National Institutes of Health.

Serial 7-Day Electrocardiogram Patch Screening for AF in High-Risk Older Women by the CHARGE-AF Score

BACKGROUND

Asymptomatic atrial fibrillation (AF) is associated with an increased risk of stroke. The yield of serial electrocardiographic (ECG) screening for AF is unknown.

OBJECTIVES

The aim of this study was to determine the frequency of AF detected by serial, 7-day ECG patch screenings in older women identified as having an elevated risk of AF according to the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology)-AF clinical prediction score.

METHODS

Postmenopausal women with a 5-year predicted risk of new-onset AF ≥5% according to CHARGE-AF were recruited from the ongoing WHISH (Women's Health Initiative Strong and Healthy) randomized trial of a physical activity intervention. Participants with AF at baseline by self-report or medical records review were excluded. Screening with 7-day ECG patch monitors was performed at baseline, 6 months, and 12 months from study enrollment.

RESULTS

On baseline monitoring, 2.5% of the cohort had AF detected, increasing to 3.7% by 6 months and 4.9% cumulatively by 12 months. Yield of patch screening was higher among participants with a higher (≥10%) CHARGE-AF score: 4.2% had AF detected at baseline, 5.9% at 6 months, and 7.2% at 12 months. Most participants with patch-identified AF never had a clinical diagnosis of AF (36 of 46 [78%]).

CONCLUSIONS

Older women with an elevated CHARGE-AF score had a high prevalence of AF on 7-day ECG patch screening. Serial screening over 12 months substantially increased the detection of AF. These data can be useful in helping identify high-risk participants for enrollment in future studies of the management of asymptomatic AF.(Women's Health Initiative Silent Atrial Fibrillation Recording Study [WHISH STAR]; NCT05366803.).

Detection of Atrial Fibrillation in a Large Population Using Wearable Devices: The Fitbit Heart Study

BACKGROUND

Morbidity from undiagnosed atrial fibrillation (AF) may be preventable with early detection. Many consumer wearables contain optical photoplethysmography (PPG) sensors to measure pulse rate. PPG-based software algorithms that detect irregular heart rhythms may identify undiagnosed AF in large populations using wearables, but minimizing false-positive detections is essential.

METHODS

We performed a prospective remote clinical trial to examine a novel PPG-based algorithm for detecting undiagnosed AF from a range of wrist-worn devices. Adults aged ≥22 years in the United States without AF, using compatible wearable Fitbit devices and Android or iOS smartphones, were included. PPG data were analyzed using a novel algorithm that examines overlapping 5-minute pulse windows (tachograms). Eligible participants with an irregular heart rhythm detection (IHRD), defined as 11 consecutive irregular tachograms, were invited to schedule a telehealth visit and were mailed a 1-week ambulatory ECG patch monitor. The primary outcome was the positive predictive value of the first IHRD during ECG patch monitoring for concurrent AF.

RESULTS

A total of 455 699 participants enrolled (median age 47 years, 71% female, 73% White) between May 6 and October 1, 2020. IHRDs occurred for 4728 (1%) participants, and 2070 (4%) participants aged ≥65 years during a median of 122 (interquartile range, 110-134) days at risk for an IHRD. Among 1057 participants with an IHRD notification and subsequent analyzable ECG patch monitor, AF was present in 340 (32.2%). Of the 225 participants with another IHRD during ECG patch monitoring, 221 had concurrent AF on the ECG and 4 did not, resulting in an IHRD positive predictive value of 98.2% (95% CI, 95.5%-99.5%). For participants aged ≥65 years, the IHRD positive predictive value was 97.0% (95% CI, 91.4%-99.4%).

CONCLUSIONS

A novel PPG software algorithm for wearable Fitbit devices exhibited a high positive predictive value for concurrent AF and identified participants likely to have AF on subsequent ECG patch monitoring. Wearable devices may facilitate identifying individuals with undiagnosed AF.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04380415.

Smartphone and wearable detected atrial arrhythmias in Older Adults: Results of a fully digital European Case finding study

Aims

Simplified detection of atrial arrhythmias via consumer-electronics would enable earlier therapy in at-risk populations. Whether this is feasible and effective in older populations is not known.

Methods and results

The fully remote, investigator-initiated Smartphone and wearable detected atrial arrhythmia in Older Adults Case finding study (Smart in OAC-AFNET 9) digitally enrolled participants ≥65 years without known atrial fibrillation, not receiving oral anticoagulation in Germany, Poland, and Spain for 8 weeks. Participants were invited by media communications and direct contacts. Study procedures adhered to European data protection. Consenting participants received a wristband with a photoplethysmography sensor to be coupled to their smartphone. The primary outcome was the detection of atrial arrhythmias lasting 6 min or longer in the first 4 weeks of monitoring. Eight hundred and eighty-two older persons (age 71 ± 5 years, range 65-90, 500 (57%) women, 414 (47%) hypertension, and 97 (11%) diabetes) recorded signals. Most participants (72%) responded to adverts or word of mouth, leaflets (11%) or general practitioners (9%). Participation was completely remote in 469/882 persons (53%). During the first 4 weeks, participants transmitted PPG signals for 533/696 h (77% of the maximum possible time). Atrial arrhythmias were detected in 44 participants (5%) within 28 days, and in 53 (6%) within 8 weeks. Detection was highest in the first monitoring week [incidence rates: 1st week: 3.4% (95% confidence interval 2.4-4.9); 2nd-4th week: 0.55% (0.33-0.93)].

Conclusion

Remote, digitally supported consumer-electronics-based screening is feasible in older European adults and identifies atrial arrhythmias in 5% of participants within 4 weeks of monitoring (NCT04579159).

Cost-effectiveness of Screening for Atrial Fibrillation Using Wearable Devices

Question

Is population-based atrial fibrillation (AF) screening using wearable devices cost-effective?

Findings

In this economic evaluation of 30 million simulated individuals with an age, sex, and comorbidity profile matching the US population aged 65 years or older, AF screening using wearable devices was cost-effective, with the overall preferred strategy identified as wearable photoplethysmography, followed conditionally by wearable electrocardiography with patch monitor confirmation (incremental cost-effectiveness ratio, $57 894 per quality-adjusted life-year). The cost-effectiveness of screening was consistent across multiple scenarios, including strata of sex, screening at earlier ages, and with variation in the association of anticoagulation with risk of stroke associated with screening-detected AF.

Meaning

This study suggests that contemporary AF screening using wearable devices may be cost-effective.

Importance

Undiagnosed atrial fibrillation (AF) is an important cause of stroke. Screening for AF using wrist-worn wearable devices may prevent strokes, but their cost-effectiveness is unknown.

Objective

To evaluate the cost-effectiveness of contemporary AF screening strategies, particularly wrist-worn wearable devices.

Design, Setting, and Participants

This economic evaluation used a microsimulation decision-analytic model and was conducted from September 8, 2020, to May 23, 2022, comprising 30 million simulated individuals with an age, sex, and comorbidity profile matching the US population aged 65 years or older.

Interventions

Eight AF screening strategies, with 6 using wrist-worn wearable devices (watch or band photoplethysmography, with or without watch or band electrocardiography) and 2 using traditional modalities (ie, pulse palpation and 12-lead electrocardiogram) vs no screening.

Main Outcomes and Measures

The primary outcome was the incremental cost-effectiveness ratio, defined as US dollars per quality-adjusted life-year (QALY). Secondary measures included rates of stroke and major bleeding.

Results

In the base case analysis of this model, the mean (SD) age was 72.5 (7.5) years, and 50% of the individuals were women. All 6 screening strategies using wrist-worn wearable devices were estimated to be more effective than no screening (range of QALYs gained vs no screening, 226-957 per 100 000 individuals) and were associated with greater relative benefit than screening using traditional modalities (range of QALYs gained vs no screening, −116 to 93 per 100 000 individuals). Compared with no screening, screening using wrist-worn wearable devices was associated with a reduction in stroke incidence by 20 to 23 per 100 000 person-years but an increase in major bleeding by 20 to 44 per 100 000 person-years. The overall preferred strategy was wearable photoplethysmography, followed conditionally by wearable electrocardiography with patch monitor confirmation, which had an incremental cost-effectiveness ratio of $57 894 per QALY, meeting the acceptability threshold of $100 000 per QALY. The cost-effectiveness of screening was consistent across multiple scenarios, including strata of sex, screening at earlier ages (eg, ≥50 years), and with variation in the association of anticoagulation with risk of stroke in the setting of screening-detected AF.

Conclusions and Relevance

This economic evaluation of AF screening using a microsimulation decision-analytic model suggests that screening using wearable devices is cost-effective compared with either no screening or AF screening using traditional methods.

Epidemiology of atrial fibrillation in the All of Us Research Program

BACKGROUND

The prevalence, incidence and risk factors of atrial fibrillation (AF) in a large, geographically and ethnically diverse cohort in the United States have not been fully described.

METHODS

We analyzed data from 173,099 participants of the All of Us Research Program recruited in the period 2017-2019, with 92,318 of them having electronic health records (EHR) data available, and 35,483 having completed a medical history survey. Presence of AF at baseline was identified from self-report and EHR records. Incident AF was obtained from EHR. Demographic, anthropometric and clinical risk factors were obtained from questionnaires, baseline physical measurements and EHR.

RESULTS

At enrollment, mean age was 52 years old (range 18-89). Females and males accounted for 61% and 39% respectively. Non-Hispanic Whites accounted for 67% of participants, with non-Hispanic Blacks, non-Hispanic Asians and Hispanics accounting for 26%, 4% and 3% of participants, respectively. Among 92,318 participants with available EHR data, 3,885 (4.2%) had AF at the time of study enrollment, while the corresponding figure among 35,483 with medical history data was 2,084 (5.9%). During a median follow-up of 16 months, 354 new cases of AF were identified among 88,433 eligible participants. Individuals who were older, male, non-Hispanic white, had higher body mass index, or a prior history of heart failure or coronary heart disease had higher prevalence and incidence of AF.

CONCLUSION

The epidemiology of AF in the All of Us Research Program is similar to that reported in smaller studies with careful phenotyping, highlighting the value of this new resource for the study of AF and, potentially, other cardiovascular diseases.

Atrial fibrillation detection using ambulatory smartwatch photoplethysmography and validation with simultaneous holter recording

BACKGROUND

Atrial fibrillation (AF)-associated embolic stroke is preventable, and AF detection may help to prevent stroke in subjects with paroxysmal AF. We aimed to evaluate the AF detection performance of smartwatch photoplethysmography (PPG) and the feasibility of ambulatory monitoring for AF detection in the daily life.

DESIGN AND METHODS

Consecutive subjects who underwent ambulatory Holter electrocardiogram (ECG) monitoring for AF detection or AF burden evaluation were enrolled. The participants underwent 24 hours of simultaneous Holter ECG monitoring and continuous PPG recording using a Garmin smartwatch. The PPG signals were processed for noise rejection, beat detection, beat labeling, and rhythm labeling for each 5-minute segment. The accuracy of the PPG AF detection was calculated using the corresponding simultaneous Holter ECG as the AF diagnostic standard.

RESULTS

Among the 200 available participants, 112 participants (56%) developed AF (the AF group). The sensitivity, specificity, and positive predicted value of AF detection in participants were 97.3%, 88.6%, and 91.6%, respectively. The area under the receiver operating characteristic curve was 0.90. When the performance was analyzed in these 5-minute segments, the sensitivity, specificity, and positive predicted values of AF detection were 97.1%, 86.8%, and 89.7%, respectively.

CONCLUSIONS

This study demonstrated the feasibility of ambulatory monitoring for AF detection using a commercial smartwatch in daily life. A smartwatch may be an alternative screening tool to standard ambulatory Holter monitoring.

Association of Echocardiographic Measures of Left Atrial Function and Size With Incident Dementia

IMPORTANCE

Atrial myopathy-characterized by alterations in left atrial (LA) function and size-is associated with ischemic stroke, independent of atrial fibrillation (AF). Electrocardiographic markers of atrial myopathy are associated with dementia, but it is unclear whether 2-dimensional echocardiographic (2DE)-defined LA function and size are associated with dementia.

OBJECTIVE

To examine the association of LA function and size with incident dementia.

DESIGN, SETTING, AND PARTICIPANTS

The Atherosclerosis Risk in Communities (ARIC) study is a community-based prospective cohort. An exploratory, retrospective analysis was conducted. ARIC centers are located in Forsyth County, North Carolina; Jackson, Mississippi; Washington County, Maryland; and suburban Minneapolis, Minnesota. For this analysis, visit 5 (2011-2013) served as the baseline. Participants without prevalent AF and stroke and who had 2DEs in 2011-2013 were included and surveilled through December 31, 2019.

EXPOSURES

LA function (reservoir strain, conduit strain, contractile strain, emptying fraction, passive emptying fraction, and active emptying fraction), and LA size (maximal and minimal volume index) as evaluated by 2DE.

MAIN OUTCOMES AND MEASURES

Dementia cases were identified using in-person and phone cognitive assessments, hospitalization codes, and death certificates. Cox proportional hazards models were used.

RESULTS

Among 4096 participants (mean [SD] age, 75 [5] years; 60% women; 22% Black individuals), 531 dementia cases were ascertained over a median follow-up of 6 years. Dementia incidence for the lowest LA quintile was 4.80 for reservoir strain, 3.94 for conduit strain, 3.29 for contractile strain, 4.20 for emptying fraction, 3.67 for passive emptying fraction, and 3.27 for active emptying fraction per 100 person-years. After full-model adjustments, there were statistically significant associations between measures of LA function and dementia; the hazard ratios (HRs) from the lowest vs highest quintile for reservoir strain were 1.98 (95% CI, 1.42-2.75); for conduit strain, 1.50 (95% CI, 1.09-2.06); for contractile strain, 1.57 (95% CI, 1.16-2.14); for emptying fraction, 1.87 (95% CI, 1.31-2.65); and for active emptying fraction, 1.43 (95% CI, 1.04-1.96). LA passive emptying fraction was not significantly associated with dementia (HR, 1.26 [95% CI, 0.93-1.71]). Dementia incidence for the highest LA maximal volume index quintile was 3.18 per 100 person-years (HR for highest vs lowest quintile, 0.77 [95% CI, 0.58-1.02]) and for the highest minimal volume index quintile was 3.50 per 100 person-years (HR for the highest vs lowest quintile, 0.95 [95% CI, 0.71-1.28]). Both measures were not significantly associated with dementia. These findings were robust to sensitivity analyses that excluded participants with incident AF or stroke.

CONCLUSIONS AND RELEVANCE

In this exploratory analysis of a US community-based cohort, several echocardiographic measures of lower LA function were significantly associated with an increased risk of subsequent dementia. Measures of LA size were not significantly associated with dementia risk. These findings suggest that impaired LA function may be a risk factor associated with dementia.

Prevalence, clinical profile, and stroke risk of atrial fibrillation in rural Andhra Pradesh, India (the ap-af study)

The burden of atrial fibrillation (AF) is increasing worldwide. It is often asymptomatic, with stroke being the first manifestation in some. AF burden in the community and the practice of stroke prophylaxis has not been studied in India. The problem might be higher in rural regions due to poor health awareness and challenges to healthcare access. This study aimed to estimate the prevalence of AF, clinical profile and stroke risk in rural India.

Methods

This is a community-based cross-sectional study done in rural Andhra Pradesh (AP). Adults from 40 villages formed the study population. We did a door-to door survey to collect information on demographics, and medical history. Electrocardiogram was recorded using a smart phone based Alivecor device. Participants diagnosed with AF underwent echocardiogram. Study cardiologists assessed the cardiovascular risk profile and collected detailed medical history.

Results

Fourteen of the 4281 individuals screened had AF (0.3%). The mean age of the sampled population was 44 ± 16.5 years with 56% women. The mean age of participants with AF was 71 ±7.8 years; males were 71%. Except for one, all were non-valvular AF. Majority had a CHA₂D₂S₂Vasc score of ≥2. Three had history of stroke. Two were on anticoagulant therapy but without INR monitoring.

Conclusion

The prevalence of AF is lower in this study compared to studies from the developed countries. Non-rheumatic cardiovascular risk factors were primary causes for AF. Non-adherence to stroke prophylaxis is a major threat that needs to be addressed.

Estimated incidence of previously undetected atrial fibrillation on a 14-day continuous electrocardiographic monitor and associated risk of stroke

Aims

There is uncertainty about whether and how to perform screening for atrial fibrillation (AF). To estimate the incidence of previously undetected AF that would be captured using a continuous 14-day ECG monitor and the associated risk of stroke.

Methods and results

We analysed data from a cohort of patients >65 years old with hypertension and a pacemaker, but without known AF. For each participant, we simulated 1000 ECG monitors by randomly selecting 14-day windows in the 6 months following enrolment and calculated the average AF burden (total time in AF). We used Cox proportional hazards models adjusted for CHA2DS2-VASc score to estimate the risk of subsequent ischaemic stroke or systemic embolism (SSE) associated with burdens of AF > and <6 min. Among 2470 participants, the median CHA2DS2-VASc score was 4.0, and 44 patients experienced SSE after 6 months following enrolment. The proportion of participants with an AF burden >6 min was 3.10% (95% CI 2.53–3.72). This was consistent across strata of age and CHA2DS2-VASc scores. Over a mean follow-up of 2.4 years, the rate of SSE among patients with <6 min of AF was 0.70%/year, compared to 2.18%/year (adjusted HR 3.02; 95% CI 1.39–6.56) in those with >6 min of AF.

Conclusions

Approximately 3% of individuals aged >65 years with hypertension may have more than 6 min of AF detected by a 14-day ECG monitor. This is associated with a stroke risk of over 2% per year. Whether oral anticoagulation will reduce stroke in these patients is unknown.

OUP accepted manuscript

More than 40 years after the first implantable cardioverter-defibrillator (ICD) implantation, sudden cardiac death (SCD) still accounts for more than five million deaths worldwide every year. Huge efforts in the field notwithstanding, it is now increasingly evident that the current strategy of long-term prevention based on left ventricular ejection fraction as the key selection criterion is actually of very limited impact, also because the largest absolute numbers of SCD are encountered in the general population not known to be at risk. It has been recently reemphasized that SCD is often not so sudden, with almost half of the victims experiencing typical warning symptoms preceding the event. Importantly, heeded and prompt medical attention can dramatically improve survival. Essentially, such timely action increases the chances of the SCD event being witnessed by emergency medical services and provides the opportunity for early intervention. In addition, newer technologies incorporating digital data acquisition, transfer between interconnected devices, and artificial intelligence, should allow dynamic, real-time monitoring of diverse parameters and therefore better identification of subjects at short-term SCD risk. Along with warning symptoms, these developments allow a new approach of near-term prevention based on the hours and minutes preceding SCD. In the present review, we challenge the current paradigm of mid- and long-term prevention using ICD in patients at the highest risk of SCD, and introduce a complementary concept applicable to the entire population that would aim to pre-empt SCD by timely detection and intervention within the minutes or hours prior to the event.

Associations Between Atrial Arrhythmias and Brain Amyloid Deposition: The ARIC-PET Study

The aim of this study is to determine if there is an association between atrial arrhythmias and brain amyloid-β (Aβ), measured on florbetapir (FBP) PET. 346 nondemented participants from the Atherosclerosis Risk in Communities study underwent FBP-PET, 185 also wore Zio® XT Patch. The associations between global cortical Aβ (> 1.2 standardized uptake value ratio) and history of atrial fibrillation, zio-defined atrial tachycardia and premature atrial contractions, each, were evaluated. Among nondemented community-dwelling older adults, we did not find an association between atrial arrhythmias and Aβ. Other brain pathology may underlie the association described between atrial arrhythmias and cognition.

Racial and Ethnic Differences in the Management of Atrial Fibrillation

Atrial fibrillation (AF) is the most common clinical arrhythmia, and it results in adverse outcomes and increased healthcare costs. Racial and ethnic differences in AF management, although recognized, are poorly understood. This review summarizes racial differences in AF epidemiology, genetics, clinical presentation, and management. In addition, it highlights the underrepresentation of racial and ethnic populations in AF clinical trials, especially trials focused on stroke prevention. Specific strategies are proposed for future research and initiatives that have potential to eliminate racial and ethnic differences in the care of patients with AF. Addressing racial and ethnic disparities in healthcare access, enrollment in clinical trials, resource allocation, prevention, and management will likely narrow the gaps in the care and outcomes of racial and ethnic minorities suffering from AF.

Differences in Left Atrial Size and Function and Supraventricular Ectopy Between Black and White Participants in the ARIC Study

Background Black Americans have more atrial fibrillation risk factors but lower atrial fibrillation risk than White Americans. Left atrial (LA) enlargement and/or dysfunction, frequent atrial tachycardia (AT), and premature atrial contractions (PAC) are associated with increased atrial fibrillation risk. Racial differences in these factors may exist that could explain the difference in atrial fibrillation risk. Methods and Results We included 2133 ARIC (Atherosclerosis Risk in Communities) study participants (aged 74±4.5 years[mean±SD], 59% women, 27% Black participants) who had echocardiograms in 2011 to 2013 and wore the Zio XT Patch (a 2-week continuous heart monitor) in 2016 to 2017. Linear regression was used to analyze (1) differences in AT/day or PAC/hour between Black and White participants, (2) differences in LA measures between Black and White participants, and (3) racial differences in the association of LA measures with AT or PAC frequency. Compared with White participants, Black participants had a higher prevalence of cardiovascular risk factors and disease, lower AT frequency, greater LA size, and lower LA function. After multivariable adjustments, Black participants had 37% (95% CI, 24%-47%) fewer AT runs/day than White participants. No difference in PAC between races was noted. Greater LA size and reduced LA function are associated with more AT and PAC runs; however, no race interaction was present. Conclusions Differences in LA measures are unlikely to explain the difference in atrial fibrillation risk between Black and White individuals. Despite more cardiovascular risk factors and greater atrial remodeling, Black participants have lower AT frequency than White participants. Future research is needed to elucidate the protective mechanisms that confer resilience to atrial arrhythmias in Black individuals.

Association of Longitudinal Changes in Cardiac Biomarkers With Atrial and Ventricular Arrhythmias (from the Atherosclerosis Risk in Communities [ARIC] Study)

We evaluated the association of longitudinal changes in circulating levels of N-terminal pro B-type natriuretic peptide (NT-proBNP) and high sensitivity cardiac troponin T (hs-cTnT) with the burden of arrhythmias as captured by 2-week ambulatory ECG monitoring. This study included 1,930 Atherosclerosis Risk in Communities Study participants who wore a leadless, ambulatory ECG monitor (Zio XT Patch) at visit 6 (2016 to 2017) and had cardiac biomarkers measured at visit 6 and visit 4 (median of 19 years earlier). The mean age of participants at V6 was 79 ± 5 years, 41% were men, and 22% were black. Adjusting for demographics, body mass index, smoking, diabetes, hypertension, stroke, left ventricular mass, cardiac medications, patch wear time, visit 4 levels of NT-proBNP and hs-cTnT, and relative change in hs-cTnT, each log-transformed unit relative increase in NT-proBNP was associated with a higher likelihood of nonsustained ventricular tachycardia (odds ratio 1.29, 95% confidence interval [CI] 1.12 to 1.48), a higher number of daily atrial tachycardia episodes (geometric mean ratio [GMR] 1.16, 95% CI 1.10 to 1.21), and a higher daily ectopic burden (premature ventricular contractions -GMR 1.42, 95% CI 1.25 to 1.62; premature atrial contractions -GMR 1.40, 95% CI 1.25 to 1.57). In fully adjusted analyses, each log-transformed unit relative increase in hs-cTnT was only found to be weakly associated with a higher daily premature ventricular contraction burden (GMR 1.31, 95% CI 1.01 to 1.70). In conclusion, longitudinal change in NT-proBNP was associated with an increased atrial and ventricular arrhythmia burden.

Predictive Accuracy of a Clinical and Genetic Risk Model for Atrial Fibrillation

BACKGROUND

Atrial fibrillation (AF) risk estimation using clinical factors with or without genetic information may identify AF screening candidates more accurately than the guideline-based age threshold of ≥65 years.

METHODS

We analyzed 4 samples across the United States and Europe (derivation: UK Biobank; validation: FINRISK, Geisinger MyCode Initiative, and Framingham Heart Study). We estimated AF risk using the CHARGE-AF (Cohorts for Heart and Aging Research in Genomic Epidemiology AF) score and a combination of CHARGE-AF and a 1168-variant polygenic score (Predict-AF). We compared the utility of age, CHARGE-AF, and Predict-AF for predicting 5-year AF by quantifying discrimination and calibration.

RESULTS

Among 543 093 individuals, 8940 developed AF within 5 years. In the validation sets, CHARGE-AF (C index range, 0.720-0.824) and Predict-AF (0.749-0.831) had largely comparable discrimination, both favorable to continuous age (0.675-0.801). Calibration was similar using CHARGE-AF (slope range, 0.67-0.87) and Predict-AF (0.65-0.83). Net reclassification improvement using Predict-AF versus CHARGE-AF was modest (net reclassification improvement range, 0.024-0.057) but more favorable among individuals aged <65 years (0.062-0.11). Using Predict-AF among 99 530 individuals aged ≥65 years across each sample, 70 849 had AF risk <5%, of whom 69 067 (97.5%) did not develop AF, whereas 28 681 had AF risk ≥5%, of whom 2264 (7.9%) developed AF. Of 11 379 individuals aged <65 years with AF risk ≥5%, 435 (3.8%) developed AF before age 65 years, with roughly half (46.9%) meeting anticoagulation criteria.

CONCLUSIONS

AF risk estimation using clinical factors may prioritize individuals for AF screening more precisely than the age threshold endorsed in current guidelines. The additional value of genetic predisposition is modest but greatest among younger individuals.

Comparative Clinical Effectiveness of Population-Based Atrial Fibrillation Screening Using Contemporary Modalities: A Decision-Analytic Model

Background Atrial fibrillation (AF) screening is endorsed by certain guidelines for individuals aged ≥65 years. Yet many AF screening strategies exist, including the use of wrist-worn wearable devices, and their comparative effectiveness is not well-understood. Methods and Results We developed a decision-analytic model simulating 50 million individuals with an age, sex, and comorbidity profile matching the United States population aged ≥65 years (ie, with a guideline-based AF screening indication). We modeled no screening, in addition to 45 distinct AF screening strategies (comprising different modalities and screening intervals), each initiated at a clinical encounter. The primary effectiveness measure was quality-adjusted life-years, with incident stroke and major bleeding as secondary measures. We defined continuous or nearly continuous modalities as those capable of monitoring beyond a single time-point (eg, patch monitor), and discrete modalities as those capable of only instantaneous AF detection (eg, 12-lead ECG). In total, 10 AF screening strategies were effective compared with no screening (300-1500 quality-adjusted life-years gained/100 000 individuals screened). Nine (90%) effective strategies involved use of a continuous or nearly continuous modality such as patch monitor or wrist-worn wearable device, whereas 1 (10%) relied on discrete modalities alone. Effective strategies reduced stroke incidence (number needed to screen to prevent a stroke: 3087-4445) but increased major bleeding (number needed to screen to cause a major bleed: 1815-4049) and intracranial hemorrhage (number needed to screen to cause intracranial hemorrhage: 7693-16 950). The test specificity was a highly influential model parameter on screening effectiveness. Conclusions When modeled from a clinician-directed perspective, the comparative effectiveness of population-based AF screening varies substantially upon the specific strategy used. Future screening interventions and guidelines should consider the relative effectiveness of specific AF screening strategies.

Prevalence and predictors of subclinical atrial fibrillation in hospitalized older adults

Subclinical atrial fibrillation (SCAF) is associated with an increased risk of clinical AF, major cardiovascular events and death. Short-term evidence on SCAF in older populations is scarce, especially in the hospital setting. We performed a cross-sectional study on 60 multimorbid older consecutive patients (aged 80+) admitted to an Internal Medicine and Geriatrics Unit for acute medical diseases with no history of AF, in order to investigate prevalence and predictors of SCAF. Portable ECG monitoring was placed on admission and ECG recording lasted for 5 days. Mean age: 85.7±4.9 years. Female prevalence: 58.3%. High burden of comorbidities: 87.9%. All enrolled patients had CHA₂DS₂-VASc score ≥3. SCAF was detected in 16 patients (26.7%) and 11 patients (18.4%) had at least a SCAF episode lasting 6 minutes or longer. No clinical, laboratory and echocardiographic parameters predicted SCAF. Patients with ≥2004 supraventricular ectopic beats/24h (SVEBs/24h) had a 6-fold higher prevalence of SCAF than patients with <411 SVEBs/24h (p=0.038). Time to first SCAF episode was within 3 days of ECG recording in all enrolled patients. SCAF is highly prevalent in older adults hospitalized for acute diseases. This finding may affect clinical management and prognosis. Our study could foster larger multicenter studies in similar settings.

The ARIC (Atherosclerosis Risk In Communities) Study: JACC Focus Seminar 3/8

ARIC (Atherosclerosis Risk In Communities) initiated community-based surveillance in 1987 for myocardial infarction and coronary heart disease (CHD) incidence and mortality and created a prospective cohort of 15,792 Black and White adults ages 45 to 64 years. The primary aims were to improve understanding of the decline in CHD mortality and identify determinants of subclinical atherosclerosis and CHD in Black and White middle-age adults. ARIC has examined areas including health disparities, genomics, heart failure, and prevention, producing more than 2,300 publications. Results have had strong clinical impact and demonstrate the importance of population-based research in the spectrum of biomedical research to improve health.

Digital health solutions in the screening of subclinical atrial fibrillation

Atrial fibrillation (AF) will become one of the biggest challenges in cardiovascular medicine in the near future. Attempting an improvement in future patient care calls explicitly for the screening of subclinical AF. Digital health solutions implementing communication technologies for the collection and analysis of digitally assessable data will most likely serve this need. Several new rapidly developing methods were introduced in the past decade. Although the vast majority still require scientific validation, the body of evidence is growing and several randomized controlled trials are planned. This review aims to give an overview of current technologies with a specific focus on mobile health (mHealth) and appraise their value with regard to the available scientific data.

Longitudinal Measures of Blood Pressure and Subclinical Atrial Arrhythmias: The MESA and the ARIC Study

Background High blood pressure (BP) is a well-known risk factor for atrial fibrillation (AF), but a single BP measurement may provide limited information about AF risk in older adults. Methods and Results This study included 1256 MESA (Multi-Ethnic Study of Atherosclerosis) and 1948 ARIC (Atherosclerosis Risk in Communities) study participants who underwent extended ambulatory electrocardiographic monitoring and who were free of clinically detected cardiovascular disease, including AF. Using BP measurements from 6 examinations (2000-2018 in MESA and 1987-2017 in ARIC study), we calculated individual long-term mean, trend, and detrended visit-to-visit variability in systolic BP and pulse pressure for each participant. Outcomes, assessed at examination 6, included subclinical AF and supraventricular ectopy. Results from each study were combined with inverse variance-weighted meta-analysis. At examination 6, the mean age was 73 years in MESA and 79 years in ARIC study, and 4% had subclinical AF. Higher visit-to-visit detrended variability in systolic BP was associated with a greater prevalence of subclinical AF (odds ratio [OR], 1.20; 95% CI, 1.02-1.38) and with more premature atrial contractions/hour (geometric mean ratio, 1.08; 95% CI, 1.01-1.15). For pulse pressure as well, higher visit-to-visit detrended variability was associated with a greater prevalence of AF (OR, 1.18; 95% CI, 1.00-1.37). In addition, higher long-term mean pulse pressure was associated with a greater prevalence of subclinical AF (OR, 1.36; 95% CI, 1.08-1.70). Conclusions Antecedent visit-to-visit variability in systolic BP and pulse pressure, but not current BP, is associated with a higher prevalence of subclinical atrial arrhythmias. Prior longitudinal BP assessment, rather than current BP, may be more helpful in identifying older adults who are at higher risk of atrial arrhythmias.

Atrial fibrillation and risk of incident heart failure with reduced versus preserved ejection fraction

OBJECTIVE

Associations between atrial fibrillation (AF) and heart failure (HF) have been established. We compared the extent to which AF is associated with each primary subtype of HF, with reduced (HFrEF) versus preserved ejection fraction (HFpEF).

METHODS

We included 25 787 participants free of baseline HF from the REGARDS (REasons for Geographic And Racial Differences in Stroke) cohort. Baseline AF was ascertained from ECG and self-reported history of physician diagnosis. Incident HF events were determined from physician-adjudicated review of hospitalisation medical records and HF deaths. Based on left ventricular ejection fraction (LVEF) at the time of HF event, HFrEF, HFpEF, and mid-range HF were defined as LVEF <40%, ≥50% and 40%-49%, respectively. Multivariable Cox proportional-hazards models examined the association between AF and HF. The Lunn-McNeil method was used to compare associations of AF with incident HFrEF versus HFpEF.

RESULTS

Over a median of 9 years of follow-up, 1109 HF events occurred (356 HFpEF, 388 HFrEF, 77 mid-range and 288 unclassified). In a model adjusted for sociodemographics, cardiovascular risk factors, and incident coronary heart disease, AF was associated with increased risk of all HF events (HR 1.67, 95% CI 1.38 to 2.01). The associations of AF with HFrEF versus HFpEF events did not differ significantly (HR 1.87 (95% CI 1.38 to 2.54) and HR 1.65 (95% CI 1.20 to 2.28), respectively; p value for difference=0.581). These associations were consistent in sex and race subgroups.

CONCLUSIONS

AF is associated with both HFrEF and HFpEF events, with no significant difference in the strength of association among these subtypes.

Frequency of cardiac arrhythmias in older adults: Findings from the Subclinical Atrial Fibrillation and Risk of Ischemic Stroke (SAFARIS) study

BACKGROUND

Prolonged monitoring of cardiac rhythm has been used to screen for subclinical atrial fibrillation (AF); little is known about other arrhythmias in the general population, especially in the elderly, who are at higher risk of arrhythmias.

METHODS

We evaluated the frequency of arrhythmias in the tri-ethnic (white, Black, Hispanic), community-based Subclinical Atrial Fibrillation and Risk of Ischemic Stroke (SAFARIS) study using a patch-based recorder for up to 14 days in 527 participants free of AF, congestive heart failure (CHF) or history of stroke. Differences according to gender, age, ethnicity and presence of hypertension, diabetes and pertinent ECG and echocardiographic variables were examined.

RESULTS

Mean age was 77.2 ± 6.8 years (37.2% men, 62.8% women). AF was present in 10 participants (1.9%), only 2 of them symptomatic. Supraventricular tachycardia (SVT) and ventricular tachycardia (VT) episodes were observed in 84.4% and 25.0% but only 13.5% and 10.6% of participants reported symptoms, respectively. Severe bradycardia (<40 bpm) was present in 12.5%. Sinus pauses and high-degree atrioventricular blocks were infrequent (2.1% and 1.5%, respectively). Most arrhythmias were more frequent in participants > 75 years; ventricular arrhythmias and severe bradycardia were more common in men. Whites had significantly more episodes of AF than Hispanics, SVT than Blacks and VT ≥ 10 beats than Hispanics and Blacks. Hypertensives had more episodes of severe bradycardia. LV hypertrophy or LVEF <55% were associated with more frequent ventricular and supraventricular arrhythmias.

CONCLUSIONS

Prolonged cardiac rhythm monitoring revealed moderate frequency of AF, but higher than expected frequencies of AF-predisposing arrhythmias. Ventricular arrhythmias were relatively frequent, whereas severe bradyarrhythmias were infrequent.

Peripheral artery disease and clinical outcomes in patients with atrial fibrillation: A report from the FANTASIIA registry

BACKGROUND

Atrial fibrillation (AF) and peripheral artery disease (PAD) are common conditions that increase cardiovascular risk. We determined the association between PAD and prognosis in a cohort of real-world patients receiving oral anticoagulant therapy for nonvalvular AF.

METHODS

We prospectively included 1956 patients (mean age 73.8 ± 9.5 years, 44.0% women) receiving oral anticoagulant therapy for AF. Clinical characteristics were collected at baseline. Patients were followed for a period of 3 years. Survival analysis and multivariable regression analyses were performed to assess variables related to death, stroke, bleeding, myocardial infarction and major adverse cardiovascular events (MACE).

RESULTS

Patients with PAD (n = 118; 6%) exhibited higher rates of cardiovascular risk factors and cardiovascular diseases. After 3 years of follow-up, there were a total of 255 deaths (no PAD 233, vs PAD 22), 45 strokes (43 vs 2), 146 major bleedings (136 vs 10) and 168 MACE (148 vs 20). On univariate analysis, there was a higher risk of cardiovascular mortality (2.02%/year no PAD vs 4.08%/year PAD, P = .02), myocardial infarction (0.99%/year no PAD vs 2.43%/year PAD, P = .02) and MACE (3.18%/year no PAD vs 6.99%/year PAD, P < .01). There was no statistically significant association with these events after multivariable adjustment.

CONCLUSIONS

In a large cohort of anticoagulated patients with AF, the presence of PAD represents a higher risk subgroup and is associated with worse crude outcomes. The exact contribution of the PAD independently of other cardiovascular diseases or risk factors requires further investigation.

2021 ISHNE/HRS/EHRA/APHRS Expert Collaborative Statement on mHealth in Arrhythmia Management: Digital Medical Tools for Heart Rhythm Professionals: From the International Society for Holter and Noninvasive Electrocardiology/Heart Rhythm Society/European Heart Rhythm Association/Asia-Pacific Heart Rhythm Society

Supplemental Digital Content is available in the text.

This collaborative statement from the International Society for Holter and Noninvasive Electrocardiology/Heart Rhythm Society/European Heart Rhythm Association/Asia-Pacific Heart Rhythm Society describes the current status of mobile health technologies in arrhythmia management. The range of digital medical tools and heart rhythm disorders that they may be applied to and clinical decisions that may be enabled are discussed. The facilitation of comorbidity and lifestyle management (increasingly recognized to play a role in heart rhythm disorders) and patient self-management are novel aspects of mobile health. The promises of predictive analytics but also operational challenges in embedding mobile health into routine clinical care are explored.

2021 ISHNE/ HRS/ EHRA/ APHRS collaborative statement on mHealth in Arrhythmia Management: Digital Medical Tools for Heart Rhythm Professionals: From the International Society for Holter and Noninvasive Electrocardiology/Heart Rhythm Society/European Heart Rhythm Association/Asia Pacific Heart Rhythm Society

This collaborative statement from the International Society for Holter and Noninvasive Electrocardiology/ Heart Rhythm Society/ European Heart Rhythm Association/ Asia Pacific Heart Rhythm Society describes the current status of mobile health ("mHealth") technologies in arrhythmia management. The range of digital medical tools and heart rhythm disorders that they may be applied to and clinical decisions that may be enabled are discussed. The facilitation of comorbidity and lifestyle management (increasingly recognized to play a role in heart rhythm disorders) and patient self‐management are novel aspects of mHealth. The promises of predictive analytics but also operational challenges in embedding mHealth into routine clinical care are explored.

2021 ISHNE/HRS/EHRA/APHRS collaborative statement on mHealth in Arrhythmia Management: Digital Medical Tools for Heart Rhythm Professionals: From the International Society for Holter and Noninvasive Electrocardiology/Heart Rhythm Society/European Heart Rhythm Association/Asia Pacific Heart Rhythm Society

This collaborative statement from the International Society for Holter and Noninvasive Electrocardiology/Heart Rhythm Society/European Heart Rhythm Association/Asia Pacific Heart Rhythm Society describes the current status of mobile health (“mHealth”) technologies in arrhythmia management. The range of digital medical tools and heart rhythm disorders that they may be applied to and clinical decisions that may be enabled are discussed. The facilitation of comorbidity and lifestyle management (increasingly recognized to play a role in heart rhythm disorders) and patient self‐management are novel aspects of mHealth. The promises of predictive analytics but also operational challenges in embedding mHealth into routine clinical care are explored.

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.

Epidemiology of Atrial Fibrillation: Geographic/Ecological Risk Factors, Age, Sex, Genetics

Atrial fibrillation is the most common arrhythmia globally. The global prevalence of atrial fibrillation is positively correlated with the sociodemographic index of different regions. Advancing age, male sex, and Caucasian race are risk factors; female sex is correlated with higher atrial fibrillation mortality worldwide likely owing to thromboembolic risk. African American ethnicity is associated with lower atrial fibrillation risk, same as Asian and Hispanic/Latino ethnicities compared with Caucasians. Atrial fibrillation may be heritable, and more than 100 genetic loci have been identified. A polygenic risk score and clinical risk factors are feasible and effective in risk stratification of incident disease.

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.

Association of Ventricular Arrhythmias With Dementia: The Atherosclerosis Risk in Communities (ARIC) Study

OBJECTIVE

We performed a cross-sectional analysis to determine whether nonsustained ventricular tachycardia (NSVT) and premature ventricular contractions (PVCs) were associated with dementia in a population-based study.

METHODS

We included 2,517 (mean age 79 years, 26% Black) participants who wore a 2-week ambulatory continuous ECG recording device in 2016 to 2017. NSVT was defined as a wide-complex tachycardia ≥4 beats with a rate >100 bpm. We calculated NSVT and PVC burden as the number of episodes per day. Dementia was adjudicated by experts. We used logistic regression to assess the associations of NSVT and PVCs with dementia.

RESULTS

The mean recording time of the Zio XT Patch was 12.6 ± 2.6 days. There were 768 (31%) participants with NSVT; prevalence was similar in White and Black participants. There were 134 (6.5%) dementia cases (5% in White, 10% in Black participants). After multivariable adjustment, there was no overall association between NSVT and dementia; however, there was a significant race interaction (p < 0.001). In Black participants, NSVT was associated with a 3.67 times higher adjusted odds of dementia (95% confidence interval [CI] 1.92-7.02) compared to those without NSVT, whereas in White participants NSVT was not associated with dementia (odds ratio [95% CI] 0.64 [0.37-1.10]). In Black participants only, a higher burden of PVCs was associated with dementia.

CONCLUSIONS

Presence of NSVT and a higher burden of NSVT and PVCs are associated with dementia in elderly Black people. Further research to confirm this novel finding and to elucidate the underlying mechanisms is warranted.

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: β 0.01; 95% CI, -0.09-0.11; SVT burden: β 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.

Serum magnesium and burden of atrial and ventricular arrhythmias: The Atherosclerosis Risk in Communities (ARIC) Study

INTRODUCTION

Low serum magnesium (Mg) is associated with an increased incidence of atrial and ventricular arrhythmias. A richer phenotyping of arrhythmia indices, such as burden or frequency, may provide etiologic insights.

OBJECTIVES

To evaluate cross-sectional associations of serum Mg with burden of atrial arrhythmias [atrial fibrillation (AF), premature atrial contractions (PAC), supraventricular tachycardia (SVT)], and ventricular arrhythmias [premature ventricular contractions (PVC), non-sustained ventricular tachycardia (NSVT)] over 2-weeks of ECG monitoring.

METHODS

We included 2513 ARIC Study visit 6 (2016-2017) participants who wore the Zio XT Patch-a leadless, ambulatory ECG-monitor-for up to 2-weeks. Serum Mg was modeled categorically and continuously. AF burden was categorized as intermittent or continuous based on the percent of analyzable time spent in AF. Other arrhythmia burdens were defined by the average number of abnormal beats per day. Linear regression was used for continuous outcomes; logistic and multinomial regression were used for categorical outcomes.

RESULTS

Participants were mean ± SD age 79 ± 5 years, 58% were women and 25% black. Mean serum Mg was 0.82 ± 0.08 mmol/L and 19% had hypomagnesemia (<0.75 mmol/L). Serum Mg was inversely associated with PVC burden and continuous AF. The AF association was no longer statistically significant with further adjustment for traditional lifestyle risk factors, only the association with PVC burden remained significant. There were no associations between serum Mg and other arrhythmias examined.

CONCLUSIONS

In this community-based cohort of older adults, we found little evidence of independent cross-sectional associations between serum Mg and arrhythmia burden.