The Relationship Between Daily Atrial Tachyarrhythmia Burden From Implantable Device Diagnostics and Stroke Risk: The TRENDS Study Detection of atrial high-rate events by continuous Home Monitoring: clinical significance in the heart failure–cardiac resynchronization therapy population Diagnosis of paroxysmal atrial fibrillation in patients with implanted pacemakers: relationship to symptoms and other variables. Higher risk of death and stroke in patients with persistent vs. paroxysmal atrial fibrillation: results from the ROCKET-AF Trial Probing oral anticoagulation in patients with atrial high rate episodes: Rationale and design of the Non–vitamin K antagonist Oral anticoagulants in patients with Atrial High rate episodes (NOAH–AFNET 6) trial Rationale and design of the Apixaban for the Reduction of Thrombo‐Embolism in Patients With Device‐Detected Sub‐Clinical Atrial Fibrillation (ARTESiA) trial Performance of a New Leadless Implantable Cardiac Monitor in Detecting and Quantifying Atrial Fibrillation Results of the XPECT Trial Stroke event rates in anticoagulated patients with paroxysmal atrial fibrillation. Focused 2012 update of the Canadian Cardiovascular Society atrial fibrillation guidelines: recommendations for stroke prevention and rate/rhythm control. Uncovering Atrial Fibrillation Beyond Short-Term Monitoring in Cryptogenic Stroke Patients: Three-Year Results From the Cryptogenic Stroke and Underlying Atrial Fibrillation Trial Atrial fibrillation after DDDR pacemaker implantation. Cryptogenic Stroke and underlying Atrial Fibrillation (CRYSTAL AF): design and rationale. Does left atrial appendage closure with a cardiac plug system reduce the stroke risk in nonvalvular atrial fibrillation patients? A single-center case series.
Background —It is unknown if brief episodes of device-detected atrial fibrillation ( AF ) increase thromboembolic event ( TE ) risk . Methods and Results —TRENDS was a prospect i ve , observational study enrolling patients with ≥1 stroke risk factor ( heart failure , hypertension , age ≥65 years , diabetes , or prior TE ) receiving pacemakers or defibrillators that monitor atrial tachycardia (AT)/AF burden ( defined as the longest total AT/AF duration on any given day during the prior 30-day period ) . This time-varying exposure was up date d daily during follow-up and related to TE risk . Annualized TE rates were determined according to AT/AF burden subsets : zero , low ( < 5.5 hours [ median duration of subsets with nonzero burden ] ) , and high ( ≥5.5 hours ) . A multivariate Cox model provided hazard ratios including terms for stroke risk factors and time-varying AT/AF burden and antithrombotic therapy . Patients ( n=2486 ) had at least 30 days of device data for analysis . During a mean follow-up of 1.4 years , annualized TE risk ( including transient ischemic attacks ) was 1.1 % for zero , 1.1 % for low , and 2.4 % for high burden subsets of 30-day windows . Compared with zero burden , adjusted hazard ratios ( 95 % CIs ) in the low and high burden subsets were 0.98 ( 0.34 to 2.82 , P=0.97 ) and 2.20 ( 0.96 to 5.05 , P=0.06 ) , respectively . Conclusions —The TE rate was low compared with patients with traditional AF with similar risk profiles . The data suggest that TE risk is a quantitative function of AT/AF burden . AT/AF burden ≥5.5 hours on any of 30 prior days appeared to double TE risk . Additional studies are needed to more precisely investigate the relationship between stroke risk and AT/AF burden Aims Uncertainty exists over the importance of device-detected short- duration atrial arrhythmias . Continuous atrial diagnostics , through home monitoring ( HM ) technology ( BIOTRONIK , Berlin , Germany ) , provides a unique opportunity to assess frequency and quantity of atrial fibrillation ( AF ) episodes defined as atrial high-rate events ( AHRE ) . Methods and results Prospect i ve data from 560 heart failure ( HF ) patients ( age 67 ± 10 years , median ejection fraction 27 % ) patients with a cardiac resynchronization therapy ( CRT ) device capable of HM from two multi-centre studies were analysed . Atrial high-rate events burden was defined as the duration of mode switch in a 24-h period with atrial rates of > 180 beats for at least 1 % or total of 14 min per day . The primary endpoint was incidence of a thromboembolic ( TE ) event . Secondary endpoints were cardiovascular death , hospitalization because of AF , or worsening HF . Over a median 370-day follow-up AHRE occurred in 40 % of patients with 11 ( 2 % ) patients developing TE complications and mortality rate of 4.3 % ( 24 deaths , 16 with cardiovascular aetiology ) . Compared with patients without detected AHRE , patients with detected AHRE>3.8 h over a day were nine times more likely to develop TE complications ( P= 0.006 ) . The majority of patients ( 73 % ) did not show a temporal association with the detected atrial episode and their adverse event , with a mean interval of 46.7 ± 71.9 days ( range 0–194 ) before the TE complication . Conclusion In a high-risk cohort of HF patients , device-detected atrial arrhythmias are associated with an increased incidence of TE events . A cut-off point of 3.8 h over 24 h was associated with significant increase in the event rate . Routine assessment of AHRE should be considered with other data when assessing stroke risk and considering anti-coagulation initiation and should also prompt the optimization of cardioprotective HF therapy in CRT patients BACKGROUND Atrial fibrillation ( AF ) is not always accompanied by clear-cut symptoms and symptoms suggestive of AF may not correspond to a genuine AF episode . The study prospect ively evaluated the burden of asymptomatic AF episodes in pacemaker patients ( for sick sinus syndrome ) with a history of documented paroxysmal AF . METHODS Consecutive patients were enrolled and implanted with dual-chamber pacemakers equipped with diagnostic features for AF monitoring .  Each patient was instructed about typical AF symptoms and was asked to keep a detailed log of symptoms . Stored pacemaker data were analyzed using only AF episodes > 30 s. RESULTS The mean follow-up was 16 + /- 6 months and 102 patients were enrolled ( 73 + /- 7 years , 59 M ) . Thirteen patients ( 13 % ) dropped out with the development of permanent AF and their data were discarded . Twenty-three patients ( 26 % ) without device-stored AF episodes all reported at least one annotated AF episode . There were 1,245 device-stored AF episodes in 66 ( 74 % ) out of 89 patients . Patients reported 1,141 episodes of AF-related symptoms . Only 240 ( 21 % ) corresponded to a genuine device-stored AF event . The sensitivity and positive predictive value of symptoms to detect AF were respectively 19 % and 21 % . Episode duration , rate increase at the onset of the arrhythmia , heart disease , or antiarrhythmic drug therapy showed no statistically significant differences comparing symptomatic and asymptomatic episodes . CONCLUSIONS Many pacemaker patients with paroxysmal AF can develop AF-like symptoms in the absence of device-stored AF . AF-related symptoms have low sensitivity and low positive predictive value in patients with permanent pacemakers Aim Anticoagulation prophylaxis for stroke is recommended for at-risk patients with either persistent or paroxysmal atrial fibrillation ( AF ) . We compared outcomes in patients with persistent vs. paroxysmal AF receiving oral anticoagulation . Methods and results Patients r and omized in the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared With Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation ( ROCKET-AF ) trial ( n = 14 264 ) were grouped by baseline AF category : paroxysmal or persistent . Multivariable adjustment was performed to compare thrombo-embolic events , bleeding , and death between groups , in high-risk subgroups , and across treatment assignment ( rivaroxaban or warfarin ) . Of 14 062 patients , 11 548 ( 82 % ) had persistent AF and 2514 ( 18 % ) had paroxysmal AF . Patients with persistent AF were marginally older ( 73 vs. 72 , P = 0.03 ) , less likely female ( 39 vs. 45 % , P < 0.0001 ) , and more likely to have previously used vitamin K antagonists ( 64 vs. 56 % , P < 0.0001 ) compared with patients with paroxysmal AF . In patients r and omized to warfarin , time in therapeutic range was similar ( 58 vs. 57 % , P = 0.94 ) . Patients with persistent AF had higher adjusted rates of stroke or systemic embolism ( 2.18 vs. 1.73 events per 100-patient-years , P = 0.048 ) and all-cause mortality ( 4.78 vs. 3.52 , P = 0.006 ) . Rates of major bleeding were similar ( 3.55 vs. 3.31 , P = 0.77 ) . Rates of stroke or systemic embolism in both types of AF did not differ by treatment assignment ( rivaroxaban vs. warfarin , Pinteraction = 0.6 ) . Conclusion In patients with AF at moderate-to-high risk of stroke receiving anticoagulation , those with persistent AF have a higher risk of thrombo-embolic events and worse survival compared with paroxysmal AF Background Oral anticoagulation prevents ischemic strokes in patients with atrial fibrillation ( AF ) . Early detection of AF and subsequent initiation of oral anticoagulation help to prevent strokes in AF patients . Implanted cardiac pacemakers and defibrillators allow seamless detection of atrial high rate episodes ( AHRE ) , but the best antithrombotic therapy in patients with AHRE is not known . Rationale Stroke risk is higher in pacemaker patients with AHRE than in those without , but the available data also show that stroke risk in patients with AHRE is lower than in patients with AF . Furthermore , only a minority of patients with AHRE will develop AF , many strokes occur without a temporal relation to AHRE , and AHRE can reflect other arrhythmias than AF or artifacts . An adequately powered controlled trial of oral anticoagulation in patients with AHRE is needed . Design The Non – vitamin K antagonist Oral anticoagulants in patients with Atrial High rate episodes ( NOAH – AFNET 6 ) trial tests whether oral anticoagulation with edoxaban is superior to prevent the primary efficacy outcome of stroke or cardiovascular death compared with aspirin or no antithrombotic therapy based on evidence ‐based indications . The primary safety outcome will be major bleeding . NOAH – AFNET 6 will r and omize 3,400 patients with AHRE , but without documented AF , aged ≥65 years with at least 1 other stroke risk factor , to oral anticoagulation therapy ( edoxaban ) or no anticoagulation . All patients will be followed until the end of this investigator‐driven , prospect i ve , parallel‐group , r and omized , event‐driven , double‐blind , multicenter phase IIIb trial . Patients will be censored when they develop AF and offered open‐label anticoagulation . The sponsor is the Atrial Fibrillation NETwork ( AFNET ) . The trial is supported by the DZHK ( German Centre for Cardiovascular Research ) , the BMBF ( German Ministry of Education and Research ) , and Daiichi Sankyo Europe . Conclusion NOAH – AFNET 6 will provide robust information on the effect of oral anticoagulation in patients with atrial high rate episodes detected by implanted devices . Graphical abstract Figure . No Caption available Background Device‐detected sub clinical atrial fibrillation ( AF ) refers to infrequent , short‐lasting , asymptomatic AF that is detected only with long‐term continuous monitoring . Sub clinical AF is common and associated with an increased risk of stroke ; however , the risk of stroke with sub clinical AF is lower than for clinical AF , and very few patients with sub clinical AF alone have been included in large AF anticoagulation trials . The net benefit of anticoagulation in patients with sub clinical AF is unknown . Design ARTESiA is a prospect i ve , multicenter , double‐blind , r and omized controlled trial , recruiting patients with sub clinical AF detected by an implanted pacemaker , defibrillator , or cardiac monitor , and who have additional risk factors for stroke . Patients with clinical AF documented by surface electrocardiogram will be excluded from the study . Participants will be r and omized to receive either apixaban ( according to st and ard AF dosing ) or aspirin 81 mg daily . The primary outcome is the composite of stroke , transient ischemic attack with diffusion‐weighted magnetic resonance imaging evidence of cerebral infa rct ion , and systemic embolism . Approximately 4,000 patients will be enrolled from around 230 clinical sites , with an anticipated mean follow‐up of 36 months until 248 adjudicated primary outcome events have occurred . Summary ARTESiA will determine whether oral anticoagulation therapy with apixaban compared with aspirin reduces the risk of stroke or systemic embolism in patients with sub clinical AF and additional risk factors Background —Current methods for detecting atrial fibrillation ( AF ) have limited diagnostic yield . Continuous monitoring with automatic arrhythmia detection and classification may improve detection of symptomatic and asymptomatic AF and subsequent patient treatment . The study purpose was to quantify the performance of the first implantable leadless cardiac monitor ( ICM ) with dedicated AF detection capabilities . Methods and Results — Patients ( n=247 ) with an implanted ICM ( Reveal XT , Medtronic Inc , Minneapolis , Minn ) who were likely to present with paroxysmal AF were selected . A special Holter device stored 46 hours of subcutaneously recorded ECG , ICM markers , and 2 surface ECG leads . The ICM  automatic arrhythmia classification was compared with the core laboratory classification of the surface ECG . Of the 206 analyzable Holter recordings collected , 76 ( 37 % ) contained at least 1 episode of core laboratory classified AF . The sensitivity , specificity , positive predictive value , and negative predictive value for identifying patients with any AF were 96.1 % , 85.4 % , 79.3 % , and 97.4 % , respectively . The AF burden measured with the ICM was very well correlated with the reference value derived from the Holter ( Pearson coefficient=0.97 ) . The overall accuracy of the ICM for detecting AF was 98.5 % . Conclusions —In this ICM validation study , the dedicated AF detection algorithm reliably detected the presence or absence of AF and the AF burden was accurately quantified . The ICM is a promising new diagnostic and monitoring tool for the clinician to treat AF patients independently of symptoms . Long-term studies are needed to evaluate the clinical benefits of the technology . Clinical Trial Registration — clinical trials.gov Identifier NCT00680927 AIMS To test the hypothesis that stroke and systemic embolic events ( SEE ) in the stroke prevention using an oral thrombin inhibitor in atrial fibrillation ( SPORTIF ) III and V trials are different between paroxysmal and persistent atrial fibrillation ( AF ) . METHODS Data analysis from two cohorts of patients enrolled in the prospect i ve SPORTIF III and V clinical trials ( n = 7329 ) ; 836 subjects ( 11.4 % ) with paroxysmal AF [ mean age 70.1 years ( SD = 9.5 ) ] were compared with 6493 subjects with persistent AF for this ancillary study . RESULTS The annual event rates for stroke/SEE are 1.73 % for persistent AF and 0.93 % for paroxysmal AF . In a multivariate analysis , after adjusting for stroke risk factors , gender and aspirin usage , the differences remained statistically significant with a higher hazard ratio ( HR ) for stroke/SEE in persistent AF [ vs. paroxysmal AF , HR 1.87 , 95 % confidence interval ( CI ) 1.04 - 3.36 ; P = 0.037 ] . In ' high risk ' patients ( with > or=2 stroke risk factors ) annual event rates for stroke/SEE were 2.08 % for persistent AF and 1.27 % for paroxysmal AF ( adjusted HR = 1.68 , 95 % CI 0.91 - 3.1 , P = 0.098 ) . Elderly patients had annual event rates for stroke/SEE of 2.38 % for persistent AF and 1.13 % for paroxysmal AF ( adjusted HR = 2.27 , 95 % CI 0.92 - 5.59 , P = 0.075 ) . Vitamin K antagonist (VKA)-naive paroxysmal AF patients had a 1.89%/year stroke/SEE rate , compared with 0.61 % for previous VKA takers ( HR = 0.33 , 95 % CI 0.11 - 1.01 , P = 0.052 ) . CONCLUSION In this large clinical trial cohort of anticoagulated AF patients , those with paroxysmal AF had stroke rates which were lower than for patients with persistent AF , although both groups had broadly similar stroke risk factors . Subjects with paroxysmal AF at ' high risk ' had stroke/SEE rates that were not significantly different to persistent AF subjects The Canadian Cardiovascular Society ( CCS ) published the complete set of 2010 Atrial Fibrillation ( AF ) Guidelines in the January , 2011 issue of the Canadian Journal of Cardiology . During its deliberations , the CCS Guidelines Committee engaged to a timely review of future evidence , with periodic composition of focused up date s to address clinical ly important advances . In 2011 , results were published from 3 pivotal AF trials : the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonist for Prevention of Stroke and Embolism Trial in Atrial Fibrillation ( ROCKET-AF ) , the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation ( ARISTOTLE ) study , and the Permanent Atrial Fibrillation Outcome Study Using Dronedarone on Top of St and ard Therapy ( PALLAS ) , comparing dronedarone with placebo in patients with permanent AF and additional cardiovascular disease risk-factor burden . Each of these large r and omized trials provided clear results with major implication s for AF management . Other important evidence that has emerged since the 2010 Guidelines includes findings about prediction instruments for AF-associated stroke and bleeding risk , stroke risk in paroxysmal-AF patients , risk-benefit considerations related to oral anticoagulation in patients with chronic kidney disease , and risk/benefit considerations in the use of antiplatelet agents , alone and in combination with each other or with oral anticoagulants , in AF patients . The Guidelines Committee judged that this extensive and important new evidence required focused updating of the 2010 Guidelines with respect to stroke prevention and rate/rhythm control . This report presents the details of the new recommendations , along with the background and rationale Background —Atrial fibrillation ( AF ) can be a cause of previously diagnosed cryptogenic stroke . However , AF can be paroxysmal and asymptomatic , thereby making detection with routine ECG methods difficult . Oral anticoagulation is highly effective in reducing recurrent stroke in patients with AF , but its initiation is dependent on the detection of AF . Cryptogenic Stroke and Underlying Atrial Fibrillation ( CRYSTAL AF ) is the first r and omized study to report the detection of AF in cryptogenic stroke patients using continuous long-term monitoring via insertable cardiac monitors ( ICM ) . Methods and Results — Patients with prior cryptogenic stroke were r and omized to control ( n=220 ) or ICM ( n=221 ) and followed for ⩽36 months . Cumulative AF detection rates in the ICM arm increased progressively during this period ( 3.7 % , 8.9 % , 12.4 % , and 30.0 % at 1 , 6 , 12 , and 36 months , respectively ) , but remained low in the control arm ( 3.0 % at 36 months ) . This result ed in oral anticoagulation prescription in 94.7 % of ICM patients with AF detected at 6 months , 96.6 % at 12 months , and 90.5 % at 36 months . Among ICM patients with AF detected , the median time to AF detection was 8.4 months , 81.0 % of first AF episodes were asymptomatic , and 94.9 % had at least 1 day with > 6 minutes of AF . Conclusions —Three-year monitoring by ICM in cryptogenic stroke patients demonstrated a significantly higher AF detection rate compared with routine care . Given the frequency of asymptomatic first episodes and the long median time to detection , these findings highlight the limitations of using traditional AF detection methods . The majority of patients with AF were prescribed oral anticoagulation therapy . Clinical Trial Registration — Clinical trials.gov ; Unique identifier : NCT00924638 INTRODUCTION Newer implantable pulse generators have data storage capabilities that permit detection of multiple episodes of atrial fibrillation ( AF ) . This study evaluated the clinical predictors and time course of AF development in a general pacemaker population . METHODS AND RESULTS Patients ( n = 231 ) received DDDR pacemakers with features that permit detection and storage of information about the date , time of onset , and duration of multiple , sequential episodes of AF . Patients were followed for 718+/-383 days . Time to first occurrence of AF , interval between first and second episode of AF , and total AF burden were determined at each follow-up visit . AF occurred more often in patients ( 68 % ) with sinus node disease than in patients with AV block ( 37 % ; P < 0.001 ) . Time to first occurrence of AF was 21.2 days ( 95 % confidence interval [ CI ] 14.7 to 30.6 days ) after pacemaker implantation . AF burden initially decreased significantly in patients ( 0.8 hours/day , 95 % CI 0.7 to 0.9 at 8 weeks after implant vs 0.6 hours/day , 95 % CI 0.4 to 0.8 at 12 months after implant ; P = 0.005 ) but then increased significantly during long-term follow-up ( 2.0 hours/day , 95 % CI 1.0 to 3.7 at 48 months after implant ; P = 0.008 ) . The long-term increase in AF burden was seen predominantly in patients with sinus node disease . A prior history of AF and the duration of follow-up were independent predictors of AF occurrence . CONCLUSION AF develops frequently after dual-chamber pacemaker implantation . AF burden increases progressively over the long term BACKGROUND Patients with atrial fibrillation ( AF ) are at increased risk for ischemic stroke . In patients who have suffered a stroke , screening for AF is routinely performed only for a short period after the stroke as part of the evaluation for possible causes . If AF is detected after an ischemic stroke , oral anticoagulation therapy is recommended for secondary stroke prevention . In 25 % to 30 % of stroke patients , the stroke mechanism can not be determined ( cryptogenic stroke ) . The incidence of paroxysmal AF undetected by short-term monitoring in patients with cryptogenic stroke is unknown , but has important therapeutic implication s on patient care . The optimum monitoring duration and method of AF detection after stroke are unknown . The purpose of this study is to evaluate the incidence of AF and time to AF detection in patients with cryptogenic stroke using an insertable cardiac monitor . STUDY DESIGN The CRYSTAL AF trial is a r and omized prospect i ve study to evaluate a novel approach to long-term monitoring for AF detection in patients with cryptogenic stroke . Four hundred fifty cryptogenic stroke patients ( by definition , without a history of AF ) will be enrolled at approximately 50 sites in Europe , Canada , and the United States . Patients will be r and omized in a 1:1 fashion to st and ard arrhythmia monitoring ( control arm ) or implantation of the subcutaneous cardiac monitor ( Reveal XT ; Medtronic , Inc , Minneapolis , MN ) ( continuous monitoring arm ) . OUTCOMES The primary end point is time to detection of AF within 6 months after stroke . The clinical follow-up period will be at least 12 months . Study completion is expected at the end of 2012 BACKGROUND Atrial fibrillation ( AF ) is the most common sustained cardiac arrhythmia and it is associated with an increased stroke risk , due mainly to cardiac embolism from the left atrial appendage ( LAA ) . Percutaneous LAA closure is a method to reduce stroke risk in AF without using anticoagulant agents . In this study we report data from an Italian experience with the LAA occluder Amplatzer Cardiac Plug ( ACP ) device ( Aga Medical Corporation , Plymouth , MN , USA ) . METHODS The study was design ed to evaluate the safety of LAA closure using ACP and the efficacy of the procedure in preventing strokes during a 1-year follow-up . Patients with permanent or paroxysmal AF , high stroke risk , and contraindication to warfarin therapy were selected for the procedure . RESULTS The LAA closure was attempted in 37 patients and succeeded in 34 cases ( 91.9 % ) . Four patients experienced serious complications ( one cardiac tamponade requiring pericardiocentesis , two device embolizations , one low-rate response AF requiring artificial pacing ) . During a 1-year follow-up , ischemic stroke occurred in one of 34 patients , result ing in a stroke rate of 2.94 % ; thus there was a stroke rate reduction of 50.2 % and 26.5 % compared to the expected stroke rate , according to CHADS2 and CHA2 DS2 VASc score . None of the patients who received ACP experienced major bleeding during the follow-up . CONCLUSION LAA closure using ACP is a relatively feasible procedure which can be performed by highly experienced operators to reduce stroke rate in patients with AF , high stroke risk , and contraindication to oral anticoagulants
Conclusion Patients with an AHRE burden over 6 min have an increased risk for stroke .
Aims Atrial fibrillation ( AF ) patients have increased risk of stroke .
In paroxysmal AF , the combination of duration and frequency of episodes defines AF burden .
In patients with cardiac implantable electronic devices ( CIEDs ) , atrial high-rate episodes ( AHREs ) can be monitored continuously and are considered as a proxy for AF .
This systematic review aims to determine the relationship between AF burden and risk of thrombo-embolic events ( TBEs ) .