Anticoagulation with edoxaban in patients with long atrial high-rate episodes ≥24†h.

BACKGROUND AND AIMS: Patients with long atrial high-rate episodes (AHREs) ≥24 h and stroke risk factors are often treated with anticoagulation for stroke prevention. Anticoagulation has never been compared with no anticoagulation in these patients. METHODS: This secondary pre-specified analysis of the Non-vitamin K antagonist Oral anticoagulants in patients with Atrial High-rate episodes (NOAH-AFNET 6) trial examined interactions between AHRE duration at baseline and anticoagulation with edoxaban compared with placebo in patients with AHRE and stroke risk factors. The primary efficacy outcome was a composite of stroke, systemic embolism, or cardiovascular death. The safety outcome was a composite of major bleeding and death. Key secondary outcomes were components of these outcomes and electrocardiogram (ECG)-diagnosed atrial fibrillation. RESULTS: Median follow-up of 2389 patients with core lab-verified AHRE was 1.8 years. AHRE ≥24 h were present at baseline in 259/2389 patients (11%, 78 ± 7 years old, 28% women, CHA2DS2-VASc 4). Clinical characteristics were not different from patients with shorter AHRE. The primary outcome occurred in 9/132 patients with AHRE ≥24 h (4.3%/patient-year, 2 strokes) treated with anticoagulation and in 14/127 patients treated with placebo (6.9%/patient-year, 2 strokes). Atrial high-rate episode duration did not interact with the efficacy (P-interaction = .65) or safety (P-interaction = .98) of anticoagulation. Analyses including AHRE as a continuous parameter confirmed this. Patients with AHRE ≥24 h developed more ECG-diagnosed atrial fibrillation (17.0%/patient-year) than patients with shorter AHRE (8.2%/patient-year; P < .001). CONCLUSIONS: This hypothesis-generating analysis does not find an interaction between AHRE duration and anticoagulation therapy in patients with device-detected AHRE and stroke risk factors. Further research is needed to identify patients with long AHRE at high stroke risk.

Closed loop stimulation reduces the incidence of atrial high-rate episodes compared with conventional rate-adaptive pacing in patients with sinus node dysfunctions.

AIMS: Subclinical atrial fibrillation (AF) is associated with increased risk of progression to clinical AF, stroke, and cardiovascular death. We hypothesized that in pacemaker patients requiring dual-chamber rate-adaptive (DDDR) pacing, closed loop stimulation (CLS) integrated into the circulatory control system through intra-cardiac impedance monitoring would reduce the occurrence of atrial high-rate episodes (AHREs) compared with conventional DDDR pacing. METHODS AND RESULTS: Patients with sinus node dysfunctions (SNDs) and an implanted pacemaker or defibrillator were randomly allocated to dual-chamber CLS (n = 612) or accelerometer-based DDDR pacing (n = 598) and followed for 3 years. The primary endpoint was time to the composite endpoint of the first AHRE lasting ≥6 min, stroke, or transient ischaemic attack (TIA). All AHREs were independently adjudicated using intra-cardiac electrograms. The incidence of the primary endpoint was lower in the CLS arm (50.6%) than in the DDDR arm (55.7%), primarily due to the reduction in AHREs lasting between 6 h and 7 days. Unadjusted site-stratified hazard ratio (HR) for CLS vs. DDDR was 0.84 [95% confidence interval (CI), 0.72-0.99; P = 0.035]. After adjusting for CHA2DS2-VASc score, the HR remained 0.84 (95% CI, 0.71-0.99; P = 0.033). In subgroup analyses of AHRE incidence, the incremental benefit of CLS was greatest in patients without atrioventricular block (HR, 0.77; P = 0.008) and in patients without AF history (HR, 0.73; P = 0.009). The contribution of stroke/TIA to the primary endpoint (1.3%) was low and not statistically different between study arms. CONCLUSION: Dual-chamber CLS in patients with SND is associated with a significantly lower AHRE incidence than conventional DDDR pacing.

Direct oral anticoagulants for stroke prevention in patients with device-detected atrial fibrillation: assessing net clinical benefit.

Subclinical, device-detected atrial fibrillation (AF) is frequently recorded by pacemakers and other implanted cardiac rhythm devices. Patients with device-detected AF have an elevated risk of stroke, but a lower risk of stroke than similar patients with clinical AF captured with surface electrocardiogram. Two randomized clinical trials (NOAH-AFNET 6 and ARTESiA) have tested a direct oral anticoagulant (DOAC) against aspirin or placebo. A study-level meta-analysis of the two trials found that treatment with a DOAC resulted in a 32% reduction in ischaemic stroke and a 62% increase in major bleeding; the results of the two trials were consistent. The annualized rate of stroke in the control arms was ∼1%. Several factors point towards overall net benefit from DOAC treatment for patients with device-detected AF. Strokes in ARTESiA were frequently fatal or disabling and bleeds were rarely lethal. The higher absolute rates of major bleeding compared with ischaemic stroke while on treatment with a DOAC in the two trials are consistent with the ratio of bleeds to strokes seen in the pivotal DOAC vs. warfarin trials in patients with clinical AF. Prior research has concluded that patients place a higher emphasis on stroke prevention than on bleeding. Further research is needed to identify the characteristics that will help identify patients with device-detected AF who will receive the greatest benefit from DOAC treatment.

The influence of atrial high-rate episodes on stroke and cardiovascular death: an update.

Atrial high-rate episodes (AHRE) are atrial tachyarrhythmias detected by continuous rhythm monitoring by pacemakers, defibrillators, or implantable cardiac monitors. Atrial high-rate episodes occur in 10-30% of elderly patients without atrial fibrillation. However, it remains unclear whether the presence of these arrhythmias has therapeutic consequences. The presence of AHRE increases the risk of stroke compared with patients without AHRE. Oral anticoagulation would have the potential to reduce the risk of stroke in patients with AHRE but is also associated with a rate of major bleeding of ∼2%/year. The stroke rate in patients with AHRE appears to be lower than the stroke rate in patients with atrial fibrillation. Wearables like smart-watches will increase the absolute number of patients in whom atrial arrhythmias are detected. It remains unclear whether anticoagulation is effective and, equally important, safe in patients with AHRE. Two randomized clinical trials, NOAH-AFNET6 and ARTESiA, are expected to report soon. They will provide much-needed information on the efficacy and safety of oral anticoagulation in patients with AHRE.

Value of ATRIA stroke risk score in predicting atrial high-rate episodes: A comparison of six different risk scores.

OBJECTIVES: Atrial high-rate episodes (AHRE) are asymptomatic atrial tachy-arrhythmias detected through continuous monitoring with a cardiac implantable electronic device (CIED). AHRE's have been associated with increased risks of developing clinically manifested atrial fibrillation (AF), thromboembolism, cardiovascular events, and mortality. Several variables has been researched and identified to predict AHRE development. The aim of this study, which compared the six frequently-used scoring systems for thromboembolic risk in AF (CHA2 DS2 -VASc, mC2 HEST, HAT2 CH2 , R2 -CHADS2 , R2 -CHA2 DS2 -VASc, and ATRIA) in terms of their prognostic power in predicting AHRE. MATERIALS AND METHODS: This retrospective study included 174 patients with CIED's. The study population was divided into two groups according to presence of AHRE: patients with AHRE (+) and patients without AHRE (-). Thereafter, patients baseline characteristics and scoring systems were analyzed for prediction of AHRE. RESULTS: The distribution of patients' baseline characteristics and scoring systems according to presence of AHRE was evaluated. Furthermore, ROC curve analyses of the stroke risk scoring systems have been investigated in terms of predicting the development of AHREs. ATRIA, which predicted AHRE with a specificity of 92% and sensitivity of 37.5% for ATRIA values of >6, performed better than other scoring systems in predicting AHRE (AUC: 0.700, 0.626-0.767 95% confidence interval (CI), p = .004) CONCLUSION: AHRE is common in patients with a CIED. In this context, several risk scoring systems have been used to predict the development of AHRE in patients with a CIED. This study's findings revealed that The ATRIA stroke risk scoring system performed better than other commonly used risk scoring systems in predicting AHRE.

Galectin-3, Inflammation, and the Risk of Atrial High-Rate Episodes in Patients with Dual Chamber Pacemakers.

Atrial high-rate episodes (AHREs) are atrial tachyarrhythmias that are exclusively detected by cardiac implantable electronic devices (CIEDs) with an atrial lead. The objective of this study was to investigate the incidence and predictive factors for AHREs, and to evaluate the ability of inflammation biomarkers to predict the occurrence of AHREs. 102 patients undergoing CIED procedure who received a dual chamber pacemaker were included. CIED interrogation was performed 1 year after the implantation procedure. Patients were divided into groups according to the occurrence of AHREs, which was the primary endpoint of the study. The mean age of the patients was of 73 ± 8.6 years and 48% were male. The incidence of AHREs was 67% at 1 year follow-up. Patients with AHREs were older, had higher left atrial indexed volume (LAVi), higher baseline galectin-3 levels (1007.5 ± 447.3 vs. 790 ± 411.7 pg/mL) and received betablockers more often, along with amiodarone and anticoagulants. Interestingly, the CHADSVASC score did not differ significantly between the two groups. A cut-off value of galectin > 990 pg/mL predicted AHREs with moderate accuracy (AUC of 0.63, 95% CI 0.52 to 0.73, p = 0.04), and this association was confirmed in the univariate regression analysis (OR 1.0012, 95% CI 1.0001 to 1.0023, p = 0.0328). However, based on the multivariate regression analysis, galectin lost its prognostic significance under the effect of LAVi, which remained the only independent predictor of AHREs (OR 1.0883, 95% CI 1.0351 to 1.1441, p = 0.0009). AHREs are common in CIEDs patients. Galectin-3 may bring additional data in the prediction of AHREs.

[Tactics of anticoagulant therapy in patients with cardiac implantable electronic devices and subclinical atrial fibrillation: A review].

Screening for atrial fibrillation (AF) has attracted considerable attention recently. Of special interest are patients with cardiac implantable electronic devices (CIEDs) that allow for recording episodes of atrial arrhythmias of various durations, including asymptomatic ones, in which case they are referred to as subclinical atrial fibrillation (SCAF). The available data suggest that the risk of thromboembolic events varies between patients with SCAF and clinically overt AF. As of today, the question regarding anticoagulant therapy in patients with SCAF remains unresolved. The article presents an overview of previous and ongoing studies on this issue, as well as current guidelines on anticoagulant use in patients with SCAF and CIEDs.

Atrial High-Rate Episodes in Patients with Devices Without a History of Atrial Fibrillation: a Systematic Review and Meta-analysis.

PURPOSE: Atrial high-rate episodes (AHREs) recorded with cardiac implantable electronic devices (CIEDs) have been associated with the development of clinical atrial fibrillation (AF) and increase in stroke and death risk. We sought to perform a systematic review with a meta-analysis to evaluate the prevalence of AHREs detected by CIEDs, their association with stroke risk, development of clinical AF, and mortality among patients without a documented history of AF. METHODS: We searched several databases, ClinicalTrials.gov, references of reviews, and meeting abstract books without any language restrictions up to 9 September 2020. We studied patients with CIEDs in whom AHREs were detected. Exclusion criterion was AF history. Our primary outcome was the risk of ischemic stroke in patients with AHREs. RESULTS: We deemed eligible eight studies for the meta-analysis enrolling a total of 4322 patients with CIED and without a documented AF history. The overall AHRE incidence ratio was estimated to be 17.56 (95% CI, 8.61 to 35.79) cases per 100 person-years. Evidence of moderate certainty suggests that patients with documented AHREs were 4.45 times (95% CI 2.87-6.91) more likely to develop clinical AF. Evidence of low confidence suggests that AHREs were associated with a 1.90-fold increased stroke risk (95% CI 1.19-3.05). AHREs were not associated with a statistically significant increased mortality risk. CONCLUSION: The present systematic review and meta-analysis demonstrated that among patients without a documented history of AF, the detection of AHREs by CIEDs was associated with significant increased risk of clinical AF and stroke. REGISTRATION NUMBER (DOI): Available in https://doi.org/10.17605/OSF.IO/ZRF6M .

Paced P-wave duration as a significant predictor for atrial high-rate episodes in patients with cardiac implantable electronic devices.

BACKGROUND: Atrial pacing (AP) can unmask or aggravate a preexisting interatrial block (IAB). The aim of our study was to determine whether AP is associated with the development of atrial high-rate episodes (AHRE) during follow-up. METHODS: Patients with dual-chamber cardiac implantable electronic devices (CIEDs), no previous documented atrial fibrillation, and with a 6-month minimum follow-up were included. In all patients, sinus and paced P-wave duration were measured. AHRE was defined as an episode of atrial rate ≥225 bpm with a minimum duration of 5 min, excluding those documented during the first 3 months after implantation. RESULTS: A total of 220 patients were included (75 ± 10 years, 61% male). After a mean follow-up of 59 ± 25 months, 46% of patients presented AHRE. Mean paced P-wave duration was significantly longer than the sinus P-wave duration (154 ± 27 vs. 115 ± 18 ms; p < .001). Sinus and paced P-waves were significantly longer in those who developed AHRE (sinus: 119 ± 20 vs. 112 ± 16; p = .006; paced: 161 ± 29 vs. 148 ± 23; p < .001). A paced P-wave ≥160 ms was the best predictor of AHRE, especially those lasting >24 h (odds ratio [OR] 4.2 [95% confidence interval (CI)] [1.6-11.4]; p = .004). CONCLUSIONS: AP significantly prolongs P-wave duration and is associated with further development of AHRE. A paced P-wave ≥160 ms is a strong predictor of AHRE and should be taken into consideration as a new definition of IAB in the presence of AP.

What to do with device-detected atrial high-rate episodes: Summary of the evidences.

Cardiac implanted electronic devices (CIEDs), that perform atrial sensing via an atrial electrode, commonly detect self-terminating atrial arrhythmias. Nomenclature of these arrhythmias is defined as atrial high-rate episodes (AHREs) and subclinical atrial fibrillation (SCAF). We have provided a comprehensive summation of the trials regarding the incidence and adverse outcomes of AHREs. The reported incidence of AHRE varies considerably (approximately 10%-70%) between studies depending on the definition of AHRE, duration of follow-up and the clinical profile of the population. There is increasing evidence related with the association between AHREs' and stroke and/or systemic embolism. However, risk of stroke and/or systemic embolism seems to be less than the risk associated with clinical AF. There is still lack of sufficient evidence related with oral anticoagulation (OAC) in patients with AHRE to reduce thromboembolic risk. Although, the strongest association of OAC treatment with reduction in stroke has been reported to be observed among patients with device detected SCAF episodes of >24 h; it is still questionable whether AHRE is a direct cause of thromboembolic event or just a marker of increased risk. Results of ongoing randomized clinical trials (NOAH-AFNET 6 and ARTESIA) will provide robust evidence on effect of OAC therapy on AHREs.

HAT2CH2 score performance predicting neurologic events after cardiac implantable electronic device.

Objectives: The HAT2CH2 score has been evaluated for predicting new-onset atrial fibrillation in several clinical conditions, but never for adverse neurologic events. We aimed to evaluate the effectiveness of HAT2CH2 score in predicting neurologic events in patients with cardiac implantable electronic device (CIED), comparing with atrial high-rate episodes (AHRE). Methods: This case-control study enrolled 314 consecutive patients aged 18 years or older with CIED implantation between January 2015 and April 2021. Patient data were analyzed retrospectively. The primary endpoint was subsequent neurologic events (NE) after implantation. AHRE was defined as > 175 bpm (Medtronic®) lasting ≥ 30 seconds. Variables associated with independent risk of NE were identified using multivariate Cox regression analysis with time-dependent covariates. Results: Patients' median age was 73 years and 61.8% of them were male. During follow-up (median 32 months), 18 NE occurred (incidence rate 2.15/100 patient-years, 95% CI 1.32-4.30). Multiple Cox regression analysis showed that the HAT2CH2 score (HR 2.424, 95% CI 1.683 - 3.492, p < 0.001) was an independent predictor for NE. Optimal HAT2CH2 score cutoff value was 3 with highest Youden index (AUC, 0.923; 95% CI, 0.881-0.966; p < 0.001). Both AHRE ≥ 1 minute and HAT2CH2 score ≥ 3 had the highest AUC of the receiver-operating characteristic (0.898, 95% CI, 0.831-0.965, p < 0.001). Significant increase was observed in NE occurrence rates using the HAT2CH2 score (p < 0.001). Conclusion: The HAT2CH2 score and episodes of AHRE lasting ≥ 1 minute are independent risk factors for NE in patients with CIED.

When to set anticoagulant therapy in asymptomatic AF? looking for a cut-off duration.

The incidence of atrial fibrillation (AF) is progressively increasing, in line with the aging of the population and with the increase in chronic diseases. The care burden of the disease and above all to its consequences (i.e. ischaemic stroke and heart failure) significantly impacts the various health systems with forecasts of exponential increase in the near future. Clinical forms of AF, i.e. those diagnosed with electrocardiogram, have a clear correlation with systemic embolic events and also with a reduction in survival. Thromboembolic prophylaxis in these patients, with anticoagulant drugs, has in fact been shown to greatly reduce the incidence of ischaemic stroke and improve survival. In recent decades, the widespread use of therapeutic intra-cardiac devices, which allow constant and continuous monitoring of myocardial electrical activity, is bringing to light a large number of atrial high rate episodes (AHREs), which are not associated with clinical manifestation. The incidence of these findings grows linearly with the duration of the observation. More independent studies have shown that AHREs are associated with a risk of stroke that is higher (about double) than controls but significantly lower than in patients with manifest AF. However, taking into consideration patients with ischaemic stroke and wearers of implantable devices, no temporal correlation emerged between the incidence of the ischaemic episode and arrhythmia. The presence of AHRE is associated with an approximately six-fold increase in the incidence of clinical AF but only a minority of these patients meet the criteria for prescribing anticoagulation. Pending the publication of the studies still in progress, the European Society of Cardiology guidelines for the treatment of AF recommend considering the initiation of anticoagulant therapy in patients with long-lasting AHRE (> 24 h) associated with a high embolic risk. In patients with episodes of shorter duration (1-24 h), especially if with high burden, anticoagulant therapy can be considered in case of very high embolic risk (e.g. secondary prevention, CHADVASc ≥ 3).

Effects of Chronic Remote Ischemic Conditioning on Atrial Fibrillation Burden in Patients with Permanent Pacemakers.

This study aimed to evaluate the effects of chronic remote ischemic conditioning (CRIC) on atrial fibrillation burden in patients with an implanted pacemaker. Sixty-six patients with permanent pacemakers were randomly divided into the CRIC group and control group after 4 weeks of screening. CRIC treatment was performed twice daily for 12 weeks. The remote ischemic conditioning protocol consisted of 4 × 5 minutes inflation/deflation of the blood pressure cuff applied in the upper arm to create intermittent arm ischemia. Sixty-one patients (31 patients in the CRIC group and 30 patients in the control group) completed the study. CRIC was well tolerated by patients after 12 weeks of treatment. The burden of atrial fibrillation (AF) in the CRIC group decreased significantly at 4 weeks compared with that at 0 weeks (14.7% ± 18.5% versus 17.0% ± 20.7%, P < 0.001), which further decreased at 12 weeks compared with that at 0 weeks (8.6% ± 10.2% versus 17.0% ± 20.7%, P < 0.001) and that at 4 weeks (8.6% ± 10.2% versus 14.7% ± 18.5%, P < 0.001), which was not observed in the control group. AF burden also reduced significantly after 12-week CRIC compared with that in the control group (8.6% ± 10.2% versus 17.6% ± 19.5%, P = 0.013). Repeated measurement ANOVA showed that the changes in AF burden were associated with CRIC instead of time (P < 0.01). In addition, there were trends that the longest duration of AF and cumulative numbers of atrial high-rate episodes (AHREs) reduced after 12-week CRIC. This study suggests that a 12-week course of CRIC treatment could reduce AF burden in patients with permanent pacemakers, supporting the widespread use of CRIC in the daily lives of these patients, which needs to be verified in the future.

Atrial fibrillation burden: an update-the need for a CHA2DS2-VASc-AFBurden score.

Atrial fibrillation (AF) is an established independent risk factor for stroke. Current guidelines regard AF as binary; either present or absent, with the decision for anti-coagulation driven by clinical variables alone. However, there are increasing data to support a biological gradient of AF burden and stroke risk, both in clinical and non-clinical AF phenotypes. As such, this raises the concept of combining AF burden assessment with a clinical risk score to refine and individualize the assessment of stroke risk in AF-the CHA2DS2VASc-AFBurden score. We review the published data supporting a biological gradient to try and construct a putative schema of risk attributable to AF burden.

The Association between Physical Activity and Cardiovascular Implantable Electronic Device-Detected Atrial High Rate Episodes.

BACKGROUND: Atrial fibrillation is the most common arrhythmia and it is associated with a higher risk of mortality and morbidity. The goal of this study was to assess the correlation between physical activity (PA) and atrial high rate episodes (AHREs) detected by cardiovascular implantable electronic devices (CIEDs). METHODS: We prospectively collected data from 81 patients from March 2017 to June 2019. Device-detected PA (hours per day) through an accelerometer and occurrence/burden of AHREs were determined at each outpatient clinic visit. Modest AHREs and long AHREs were defined as at least 1 episode of AHREs lasting ≥ 12 hours and 24 hours, respectively. The percentage of total AHREs in the follow-up period was defined as the burden of AHREs. Generalized estimating equations were used to explore the association between PA and occurrence/burden of AHREs to account for repeated measures within a participant. RESULTS: The patients had 336 follow-up visits (mean 4.1 visits each). The prevalence rates of device-detected modest AHREs and long AHREs were 4.8% and 3.9%, respectively. More PA (hours per day) was associated with a lower risk of modest AHREs [odds ratio (OR) 0.671, 95% confidence interval (CI) 0.452-0.997, p = 0.048] and long AHREs (OR 0.536, 95% CI 0.348-0.824, p = 0.004) after adjusting for age, sex, and basic characteristics. More PA had a trend of association with fewer AHREs (ß -0.255, 95% CI -0.512 to 0.001, p = 0.051). CONCLUSIONS: More PA was associated with a lower risk of AHREs detected by CIEDs in older patients. PA may reduce the risk of AHREs.

What do we do about atrial high rate episodes?

Atrial high rate episodes (AHREs) are defined as asymptomatic atrial tachyarrhythmias detected by cardiac implantable electronic devices with atrial sensing, providing automated continuous monitoring and tracings storage, occurring in subjects with no previous clinical atrial fibrillation (AF) and with no AF detected at conventional electrocardiogram recordings. AHREs are associated with an increased thrombo-embolic risk, which is not negligible, although lower than that of clinical AF. The thrombo-embolic risk increases with increasing burden of AHREs, and moreover, AHREs burden shows a dynamic pattern, with tendency to progression along with time, with potential transition to clinical AF. The clinical management of AHREs, in particular with regard to prophylactic treatment with oral anticoagulants (OACs), remains uncertain and heterogeneous. At present, in patients with confirmed AHREs, as a result of device tracing analysis, an integrated, individual and clinically-guided assessment should be applied, taking into account the patients' risk of stroke (to be reassessed regularly) and the AHREs burden. The use of OACs, preferentially non-vitamin K antagonists OACs, may be justified in selected patients, such as those with longer AHREs durations (in the range of several hours or ≥24 h), with no doubts on AF diagnosis after device tracing analysis and with an estimated high/very high individual risk of stroke, accounting for the anticipated net clinical benefit, and informed patient's preferences. Two randomized clinical trials on this topic are currently ongoing and are likely to better define the role of anticoagulant therapy in patients with AHREs.

Atrial high-rate episodes: prevalence, stroke risk, implications for management, and clinical gaps in evidence.

Self-terminating atrial arrhythmias are commonly detected on continuous rhythm monitoring, e.g. by pacemakers or defibrillators. It is unclear whether the presence of these arrhythmias has therapeutic consequences. We sought to summarize evidence on the prevalence of atrial high-rate episodes (AHREs) and their impact on risk of stroke. We performed a comprehensive, tabulated review of published literature on the prevalence of AHRE. In patients with AHRE, but without atrial fibrillation (AF), we reviewed the stroke risk and the potential risk/benefit of oral anticoagulation. Atrial high-rate episodes are found in 10-30% of AF-free patients. Presence of AHRE slightly increases stroke risk (0.8% to 1%/year) compared with patients without AHRE. Atrial high-rate episode of longer duration (e.g. those >24 h) could be associated with a higher stroke risk. Oral anticoagulation has the potential to reduce stroke risk in patients with AHRE but is associated with a rate of major bleeding of 2%/year. Oral anticoagulation is not effective in patients with heart failure or survivors of a stroke without AF. It remains unclear whether anticoagulation is effective and safe in patients with AHRE. Atrial high-rate episodes are common and confer a slight increase in stroke risk. There is true equipoise on the best way to reduce stroke risk in patients with AHRE. Two ongoing trials (NOAH-AFNET 6 and ARTESiA) will provide much-needed information on the effectiveness and safety of oral anticoagulation using non-vitamin K antagonist oral anticoagulants in patients with AHRE.

Wearable and implantable diagnostic monitors in early assessment of atrial tachyarrhythmia burden.

Atrial fibrillation (AF) is the cause of substantial direct patient morbidity and a frequent cause of emergency room visits. Even when asymptomatic, AF remains a major cause of stroke, particularly among the elderly. As the risk of both AF and stroke increase with age, the importance of AF-related stroke is growing as a result of demographic shifts in many countries. Oral anticoagulation is highly effective at preventing stroke due to AF; however, AF remains undetected in a large number of individuals. The last decade has witnessed the development of many new technologies to detect AF. Screening studies using single-time point or repeated discrete screening methods have uncovered previously undiagnosed AF in 1-3% of asymptomatic individuals. However, continuous monitoring with implanted devices demonstrates short-lasting AF in over one-third of older individuals with cardiovascular risk factors. Debate remains regarding the minimum burden of AF that is associated with an increase in stroke risk, and the threshold for using oral anticoagulation. Over the next 5 years, ongoing studies will help clarify how wearable and implantable technology can be used to improve outcomes in patients with previously unrecognized AF.

Burden of Implanted-Device-Detected Atrial High-Rate Episode Is Associated With Future Heart Failure Events　- Clinical Significance of Asymptomatic Atrial Fibrillation in Patients With Implantable Cardiac Electronic Devices.

BACKGROUND: The relationship between atrial high-rate episode (AHRE) burden (i.e., the frequency of atrial tachyarrhythmia) and heart failure (HF) risk is unclear. We hypothesized that new-onset and higher burden of AHRE are associated with HF. Methods and Results: We included 104 consecutive patients with cardiac implantable electronic devices (CIEDs) capable of continuous atrial rhythm monitoring. Patients with AF history were excluded. To stratify patients, AHREs were evaluated only during the initial 1 year after CIED implantation. The primary endpoint was all-cause death or new-onset or worsening HF that required unplanned hospitalization or readjustment of HF drug therapy. At 1 year after CIED implantation, 34/104 patients (33%) exhibited AHREs. No difference in basal clinical characteristics except for left ventricular ejection fraction between patients with and without new-onset AHREs was found. AHRE groups had more HF events than the non-AHRE group. All patients were divided into 3 groups based on AHRE burden: none, low, and high. Worsening HF was observed in 12 patients (12%). Cox hazard analysis revealed that AHRE and higher AHRE burden were independent predictive factors for worsening HF. The high group showed a higher risk for HF than the non-AHRE groups, but no significant difference was found between the low- and non-AHRE groups. CONCLUSIONS: New-onset higher AHRE burden was associated with subsequent risk for HF in patients with CIEDs.