Detection Rate Of Atrial Fibrillation Research Articles

Abstract TP489: Atrial Fibrillation Detection Following Implanted Cardiac Monitor Placement in Patients with Embolic Stroke of Undetermined Source

Objective: Determine atrial fibrillation detection rates in patients with ischemic stroke and TIA following implanted cardiac monitor placement. Introduction: Annually an estimated 795,000 Americans suffer a stroke. Embolic stroke of undetermined source (ESUS) is estimated to account for 25-30% of all ischemic strokes. While atrial fibrillation is associated with an increased risk of ischemic stroke, AF is often asymptomatic. Current guidelines recommend antiplatelet therapy for secondary stroke prevention in ESUS. Unfortunately the prevalence of atrial fibrillation in ESUS is unknown. Thus detection of asymptomatic AF in ESUS has potential therapeutic implications. Methods: To determine the frequency of asymptomatic AF, a retrospective chart review was conducted of patients admitted to a single center 627 bed quaternary referral hospital and certified comprehensive stroke center in Hennepin County, Minnesota. Between June of 2015 and June of 2018, 237 implanted cardiac monitors (ICM) were placed in patients with a primary diagnosis of stroke or TIA. Inclusion criteria was admission to the stroke center or evaluation in the TIA clinic, primary diagnosis of ischemic stroke or TIA, diagnosis of ESUS, and placement of ICM. Diagnosis of ESUS was confirmed by the stroke medical director. Patients were monitored remotely for a minimum of six and a maximum of eighteen months post ICM insertion. Remote monitoring was discontinued at time of AF detection confirmed by an electrophysiologist. Medication adjustments were directed by the stroke service. Results: Multivariable analysis will be reported to compare patients with positive and negative AF detection, age, sex, ethnicity/race, and CHA 2 DS 2 -VASC score. Hazard ratios will be calculated for AF detection at 6 and 12 months post ICM insertion. Conclusion: Since AF is often asymptomatic, cardiac monitoring plays an important role in evaluation of ESUS. Detection of AF often results in initiation of anticoagulation which is superior to antiplatelet agents for stroke prevention in AF. Identifying asymptomatic AF may reduce recurrent stroke rates in ESUS.

Atrial fibrillation detection using single lead portable electrocardiographic monitoring: a systematic review and meta-analysis

ObjectivesRecent technology advances have allowed for heart rhythm monitoring using single-lead ECG monitoring devices, which can be used for early diagnosis of atrial fibrillation (AF). We sought to investigate the...

Atrial Fibrillation Detection Using a Novel Cardiac Ambulatory Monitor Based on Photo-Plethysmography at the Wrist.

BackgroundLong‐term continuous cardiac monitoring would aid in the early diagnosis and management of atrial fibrillation (AF). This study examined the accuracy of a novel approach for AF detection using photo‐plethysmography signals measured from a wrist‐based wearable device.Methods and Results ECG and contemporaneous pulse data were collected from 2 cohorts of AF patients: AF patients (n=20) undergoing electrical cardioversion (ECV) and AF patients (n=40) that were prescribed for 24 hours ECG Holter in outpatient settings (HOL). Photo‐plethysmography and acceleration data were collected at the wrist and processed to determine the inter‐pulse interval and discard inter‐pulse intervals in presence of motion artifacts. A Markov model was deployed to assess the probability of AF given irregular pattern in inter‐pulse interval sequences. The AF detection algorithm was evaluated against clinical rhythm annotations of AF based on ECG interpretation. Photo‐plethysmography recordings from apparently healthy volunteers (n=120) were used to establish the false positive AF detection rate of the algorithm. A total of 42 and 855 hours (AF: 21 and 323 hours) of photo‐plethysmography data were recorded in the ECV and HOL cohorts, respectively. AF was detected with >96% accuracy (ECV, sensitivity=97%; HOL, sensitivity=93%; both with specificity=100%). Because of motion artifacts, the algorithm did not provide AF classification for 44±16% of the monitoring period in the HOL group. In healthy controls, the algorithm demonstrated a <0.2% false positive AF detection rate.ConclusionsA novel AF detection algorithm using pulse data from a wrist‐wearable device can accurately discriminate rhythm irregularities caused by AF from normal rhythm.

Detection and management of atrial fibrillation after cryptogenic stroke or embolic stroke of undetermined source.

Cryptogenic stroke (CS) and embolic stroke of unknown source (ESUS) represent a major challenge to healthcare systems worldwide. Atrial fibrillation (AF) is commonly found after CS or ESUS. Independent of the mechanism of the index CS or ESUS, detection of AF in these patients offers the opportunity to reduce the risk of stroke recurrence by prescribing an anticoagulant instead of aspirin. The detection of AF may be pursued with different monitoring strategies. Comparison of monitoring strategies should take into account that AF detection rates reported in published studies, and then pooled in meta-analyses, are not only a function of the monitoring strategy itself, but also depend on patient-related, device-related, and study design-related factors. Once AF is found, the decision to anticoagulate a patient should be made on the basis of AF burden and the baseline risk of the patient. Empirical anticoagulation in patients with ESUS and no evidence of AF is an intriguing but still-unproven strategy and therefore should not be adopted outside of randomized clinical trials.

A COMPARISON OF ATRIAL FIBRILLATION MONITORING STRATEGIES IN PATIENTS AT HIGH RISK FOR ATRIAL FIBRILLATION AND STROKE: RESULTS FROM THE REVEAL AF STUDY

Reducing atrial fibrillation (AF)-related stroke requires timely diagnosis of AF in patients with stroke risk factors. Recent single-arm trials with insertable cardiac monitors (ICM) have shown high AF detection rates in at-risk populations. We estimated the corresponding AF incidence with various

Refinement of detecting atrial fibrillation in stroke patients: results from the TRACK-AF Study.

Detection of occult atrial fibrillation (AF) is crucial for optimal secondary prevention in stroke patients. The AF detection rate was determined by implantable cardiac monitor (ICM) and compared to the prediction rate of the probability of incident AF by software based analysis of a continuously monitored electrocardiogram at follow-up (stroke risk analysis, SRA); an optimized AF detection algorithm is proposed by combining both tools. In a monocentric prospective study 105 out of 389 patients with cryptogenic stroke despite extensive diagnostic workup were investigated with two additional cardiac monitoring tools: (a) 20 months' monitoring by ICM and (b) SRA during hospitalization at the stroke unit. The detection rate of occult AF was 18% by ICM (n = 19) (range 6-575 days) and 62% (n = 65) had an increased risk for AF predicted by SRA. When comparing the predictive accuracy of SRA to ICM, the sensitivity was 95%, specificity 35%, positive predictive value 27% and negative predictive value 96%. In 18 patients with AF detected by ICM, SRA also showed a medium risk for AF. Only one patient with a very low risk predicted by SRA developed AF revealed by ICM after 417 days. A combination of SRA and ICM is a promising strategy to detect occult AF. SRA is reliable in predicting incident AF with a high negative predictive value. Thus, SRA may serve as a cost-effective pre-selection tool identifying patients at risk for AF who may benefit from further cardiac monitoring by ICM.

Abstract WP199: Left Atrial Volume Index and PR Interval Are Independent Predictors of Atrial Fibrillation in Embolic Stroke Patients With Insertable Cardiac Monitor

Introduction: The use of insertable cardiac monitors (ICM) improved the detection rate of atrial fibrillation (AF) in patients with embolic strokes (ES). However, given cost of the device, current indications and availability of implant procedure, the optimal patient population that would benefit from the device remains unknown. Objectives: We sought to determine 1) the incidence of AF in patients with ES in our population and 2) whether certain variables are predictive of AF in patients with ES. Methods: A case control study was conducted from January 1, 2015 to June 23, 2017. Patients admitted to the Gates Vascular Institute with ES on MRI and CT angiogram but no evidence of AF on telemetry underwent Reveal LINQ ICM implant prior to discharge. Demographics, EKG and echocardiographic variables were assessed. Statistical analysis was conducted using SPSS version 22 and R v.1.0.44. Independent T tests were applied for continuous variables and Chi Square or Fisher’s exact test for categorical variables. Cox proportional hazard model was used to analyze whether certain variables were associated with increased odds of AF. A p-value of &lt;0.05 was considered statistically significant. Results: A total of 177 patients were enrolled and followed for 478 ± 179 days. AF was detected in 31% (n=55). Mean age ± SD (positive vs. negative AF on ICM) was 71.1 ± 12.0 vs. 68.6 ± 11.8, p=0.20. Age, gender, race, BMI, systolic, diastolic blood pressures, cholesterol and HBA1c were not significantly different between the two groups. Significant univariate predictors of AF included PR interval (hazard ratio [HR] 1.19 per 10 milliseconds, p &lt; 0.001) and Left Atrial Volume Index (LAVI) (HR 1.04 per 1 mL/m 2 , p = 0.01). In multivariate analysis, both PR interval and LAVI remained significant predictors of AF (HR 1.3, p &lt; 0.001; HR 1.05, p &lt; 0.001, respectively). Using a risk-score formulated from these predictors, we found that patients in the top quartile had a five fold higher rate of AF detection compared to the lowest quartile. Conclusion: In summary, our atrial fibrillation detection rate was 31%. PR interval and Left Atrial Volume Index were found to be both independent and multivariate predictors of atrial fibrillation in embolic stroke patients with insertable cardiac monitor.

Abstract 189: Identifying Patients at Highest Risk of Developing Atrial Fibrillation and the Role of Remote Prior Stroke: Insights From the REVEAL AF Study

Introduction: Recent trials using insertable cardiac monitors (ICMs) show high rates of atrial fibrillation (AF) in those at risk of developing AF based on demographics. Further identifying subsets who could benefit most from ICMs is desirable. We evaluated if the recently-developed HAVOC risk score which has predicted AF in cryptogenic stroke patients also predicts AF detection by ICMs in those without a recent stroke. Methods: Participants from the prospective REVEAL AF study, which reported frequent clinically unrecognized AF in patients at risk for AF (CHADS 2 scores ≥3 or =2 with ≥1 additional risk factor), with ICM data and not on anti-arrhythmic drugs were included. Ischemic stroke &lt;1 year ago excluded participation. HAVOC scores were calculated using points for hypertension (2), age ≥75 (2), valvular disease (2), vascular disease (1), obesity (1), congestive heart failure (4), and coronary artery disease (2). Prior stroke, an AF outcome, generally not a cause, is not included. Score classification is: low (0-4), intermediate (5-9), or high (10-14). Corresponding AF detection rates were compared via the log-rank test. Results: Among 391 participants, 95 (24%), 241 (62%), and 55 (14%) had low, intermediate, and high HAVOC scores, respectively. At 18 months, AF incidence was significantly less for those with low (19.5%) vs intermediate (32.1%) or high (34.2%) scores (p=0.045, Figure). At 18 months, AF incidence was similar among those with (n=79) vs. without (n=312) a history of remote stroke (27.1% vs. 29.9%; p&gt;0.05, median time from stroke to ICM insertion=4 years). Conclusions: The HAVOC risk score identified a subset of high risk individuals at greatest risk of developing AF. AF incidence rates were similar among those with and without prior remote stroke. Remote strokes may not be a strong predictor of AF in this population. HAVOC scores could be a useful approach to identify those at high likelihood of manifesting AF, as best documented by long-term monitoring.

Abstract 125: Validation of a Clinical Risk Score for Predicting Atrial Fibrillation in Cryptogenic Stroke Patients With Insertable Cardiac Monitors: Insights From the CRYSTAL AF Study

Introduction: Insertable cardiac monitors (ICMs) have been shown to be superior to standard monitoring for the detection of underlying atrial fibrillation (AF) in patients (pts) with cryptogenic stroke (CS). However, identifying a subset of CS pts who would benefit most from ICMs is desirable. We evaluated whether a recently developed risk score for the prediction of clinically-detected AF in CS pts (the HAVOC score) also predicted the presence of subclinical AF as detected by ICMs. Methods: Pts who received an ICM in the CRYSTAL AF study were included. HAVOC scores were retrospectively calculated by assigning points based on the presence of hypertension (2), age ≥75 (2), valvular disease (2), vascular disease (1), obesity (1), congestive heart failure (4), and coronary artery disease (2), resulting in scores from 0-14 with pts assigned to Group A (0-1), B (2-3), or C (≥4) based on their score. The ICM monitored cardiac rhythm continuously for up to 3 years to identify the presence of AF. AF detected by the ICM (≥2 minutes) was correlated with HAVOC score groupings via the chi-square test. Results: A total of 214 ICM pts (mean age 61±11 years, 66% male) were followed for 1.8±0.7 years. Mean and median HAVOC scores were 2.4±2.6 and 2 [1-3], respectively, with 89% having scores ≤4. The AF detection rate at 3 years was 27%. Mean HAVOC scores tended to be higher among pts with vs. without AF detected (2.9±1.8 vs. 2.3±2.1, p=0.07). The proportion of patients with AF increased significantly from 11% to 18% to 32% as HAVOC scores progressed from Groups A to B to C, respectively (p=0.02). Conclusions: In a cohort of CS pts with ICMs, the prevalence of AF increased significantly with increasing HAVOC score groups. This parameter should be considered when comparing AF detection rates between different studies, as the vast majority of CRYSTAL AF pts had very low HAVOC scores. Further validation of this risk score in CS pts with ICMs is warranted across a broader spectrum of risk measured by this novel score.

Sensitive Detection of Atrial Fibrillation in Acute Stroke Patients by Short-Term Bedside Electrocardiography Monitoring Software Analysis

Background: Atrial fibrillation (AF) is an important cause of stroke. Continuous electrocardiography (ECG) monitoring with software-based analysis algorithms has been suggested to enhance the AF detection rate. We investigated the ability of stroke risk analysis (SRA) in the detection of AF in acute stroke patients. Methods: Consecutive stroke patients numbering 1,153 were screened. Patients with cardioembolic stroke related to AF (n = 296, paroxysmal n = 63, persistent n = 233) and patients with cryptogenic stroke (n = 309) after standard diagnostic work-up (bedside ECG monitoring, ultrasound, transesophageal echocardiography, 24 h Holter ECG) received SRA during their stay at the Stroke Unit. Determination of AF risk by SRA in the patients with AF and in the patient group with cryptogenic stroke was assessed and compared. Results: Median SRA monitoring analysis time was 16 h (range 2–206 h, interquartile range 10–36). In AF patients, SRA also detected a possible or definitive AF in 98%. The overall sensitivity of SRA to detect possible or definitive AF in patients with proven AF by standard diagnostic work up and cryptogenic stroke was 98%, specificity 27%, positive predictive value 56%, and the negative predictive value (NPV) was 92%. Area under ROC curve was 0.622. Conclusion: SRA was found to be highly sensitive to detect possible or definitive AF in clinical routine within a short monitoring time. However, low specificity and poor accuracy do not allow diagnosing AF by SRA alone, but with the high NPV compared to current diagnostic standard, it is a valid diagnostic tool to rule out AF. Thereby, SRA is a contribution to clarify stroke etiology.

Opportunistic screening for atrial fibrillation in a real-life setting in general practice in Denmark-The Atrial Fibrillation Found On Routine Detection (AFFORD) non-interventional study.

Atrial fibrillation (AF) is a chronic disease with an incidence increasing steeply by age and affecting more than 11 million patients in Europe and the United States. Diagnosing AF is essential for the prevention of stroke by oral anticoagulation. Opportunistic screening for AF in patients ≥65 years of age is recommended by the European and Danish Societies of Cardiology. The study aim was to examine the detection rate of AF in consecutively screened patients in the primary care setting in Denmark. In an open, non-interventional, cluster, multicenter, cross-sectional, observational study patients ≥65 years of age entering consecutively into general practice clinics were invited to nurse-assisted opportunistic screening for AF. The General Practice (GP) clinics participating were randomized to patient inclusion in three age groups: 65–74, 75–84, and ≥85 years respectively. All patients underwent pulse palpation followed by 12-led electrocardiogram in case of irregular pulse. Two cardiologists validated all electrocardiogram examinations. Forty-nine general practice clinics recruited in total 970 patients split into three age groups; 480 patients (65–74 years), 372 (75–84 years), and 118 patients ≥85 years of age. Co-morbidities increased by age with hypertension being most frequent. Eighty-seven patients (9%) were detected with an irregular pulse, representing 4.4%, 10.5% and 22.9%, respectively in the three age groups. Assessment of electrocardiograms by the GP showed suspicion of AF in 13 patients with final verification of electrocardiograms by cardiologists revealing 10 AF-patients. The highest detection rate of AF was found in the ≥85 age group (3.39%) followed by the 65–74 age group (0.83%) and the 75–84 age group (0.54%). Opportunistic screening of AF in primary care is feasible and do result in the detection of new AF-patients. Close collaboration with cardiologists is advisable to avoid false positive screening results.

Automatic Blood Pressure Monitor Accurately Detects AF

Automatic blood pressure screening with a blood pressure monitor can accurately detect new cases of atrial fibrillation (AF) among older populations, according to a recent U.S. study. Long-term residents of skilled nursing facilities frequently have multiple risk factors for strokes due to AF, and studies have shown that screening for AF may allow residents the opportunity to begin treatment that lowers their risk for stroke. The American Heart Association and the British National Institute for Health and Care Excellence (NICE) both recommend AF screening for residents 65 years and older in primary care clinics. NICE specifically recommends the Microlife WatchBP Home A (BPM-AF), an automatic blood pressure monitor that can detect AF when set to a triple-reading mode. Results from past studies have shown that the monitor has a sensitivity of 95% and specificity of 90% for detecting AF. In 2016 Joseph Wiesel, MD, and Thomas J. Salomone, DrNP, FNP, conducted a pilot program to assess the efficacy of the BPM-AF monitor for AF screening among long-term residents at an SNF in the northeastern United States. Their results, published in the American Journal of Cardiology [July 24, 2017; doi: 10.1016/j.amjcard.2017.07.016], showed that the BPM-AF identified 9 residents with possible AF out of 101 residents screened. In five of those residents the AF was confirmed by a 12-lead electrocardiogram (ECG), and in two of the remaining four it was confirmed using an immediate 30-second single-lead ECG. Overall, 113 residents of extended care units who were 65 and older were eligible to participate, and a total of 101 residents were screened. The average age of the screened residents was 77.7 years, and men made up 52% of the cohort. Residents with dementia, using a ventilator, or housed in short-term rehabilitation were excluded, as were residents with previously diagnosed AF, those who had a pacemaker or a defibrillator, and those who were unavailable or uncooperative. The investigators used the BPM-AF in the automatic three-sequential-reading mode, as recommended for AF screening and maximum blood pressure accuracy. If the BPM-AF detected possible AF, the nurse on the unit would request a standard 12-lead ECG as per routine practice. All 12-lead ECGs in the study were interpreted by a board-certified cardiologist who provided routine ECG readings for the facility. When the investigators could not perform a 12-lead ECGs until several days after an abnormal BPM-AF reading, they immediately collected a backup with a 30-second single-lead ECG handheld device. In the cases where the resident’s delayed 12-lead ECG did not show AF, a board-certified cardiologist interpreted the 30-second single-lead ECG result. The residents with AF confirmed by either the 12-lead ECG or the immediate single-lead ECG were considered to have AF. With one screening BMP-AF reading and a routine confirmatory 12-lead ECG, the incidence of new AF was 4.9%. Including the residents whose AF was confirmed by an immediate 30-second single-channel ECG, the incidence rate increased to 6.9%. The false-positive rate was 2%. The investigators noted that their AF detection rates were significantly higher than the 1.61% rate obtained via systematic screening using one ECG in participants 65 and older from a general outpatient medical population (BMJ 2007;335:383–388) and the 1.2% incidence rate recorded for ECG screening among 75-year-old community residents (Circulation 2013;127:930–937). “Residents of skilled nursing facilities may be at particularly high risk of undiagnosed AF and would benefit from routine screening for AF,” wrote Drs. Wiesel and Salomone. They also noted that “given the high prevalence of previously undiagnosed AF found in this study, expanding the criteria for AF screening to include younger skilled nursing facility residents may be appropriate.” Braxton Poe is a freelance writer in the Philadelphia area. We certainly have the technology to do widespread screening for asymptomatic atrial fibrillation in our nursing home residents. Considering the prevalence of risk factors for stroke that would make them good candidates for anticoagulation, this may become the standard of care. However, we need to consider burdens vs. benefits, and allow our patients or their decision-makers to make informed decisions about whether such screening is appropriate for an individual patient. If patients are at excessively high risk for bleeding or falls, or if they have substantially limited life expectancy, then perhaps it is of no benefit to know that they may be experiencing AF since anticoagulation would be relatively contraindicated. Antiarrhythmic medications could be considered for some. And for others, nonpharmacological interventions such as radiofrequency ablation might be considered. As long as we keep the individual patient’s goals of care and specific medical profile in mind, this technology has the potential to prevent many strokes. —Karl Steinberg, MD, CMD, HMDC Editor in Chief

Yield of atrial fibrillation detection with Textile Wearable Holter from the acute phase of stroke: Pilot study of Crypto-AF registry.

We describe the feasibility of monitoring with a Textile Wearable Holter (TWH) in patients included in Crypto AF registry. We monitored cryptogenic stroke patients from stroke onset (<3days) continuously during 28days. We employed a TWH composed by a garment and a recorder. We compared two garments (Lead and Vest) to assess rate of undiagnosed Atrial Fibrillation (AF) detection, monitoring compliance, comfortability (1 to 5 points), skin lesions, and time analyzed. We describe the timing of AF detection in three periods (0-3, 4-15 and 16-28days). The rate of undiagnosed AF detection with TWH was 21.9% (32 out of 146 patients who completed the monitoring). Global time compliance was 90% of the time expected (583/644h). The level of comfortability was 4 points (IQR 3-5). We detected reversible skin lesions in 5.47% (8/146). The comfortability was similar but time compliance (in hours) was longer in Vest group 591 (IQR [521-639]) vs. Lead 566 (IQR [397-620]) (p=0.025). Also, time analyzed was more prolonged in Vest group 497 (IQR [419-557]) vs. Lead (336h (IQR [140-520]) (p=0.001)). The incidence of AF increases from 5.6% (at 3days) to 17.5% (at 15th day) and up to 20.9% (at 28th day). The percentage of AF episodes detected only in each period was 12.5% (0-3days); 21.7% (4-15days) and 19% (16-28days). 28days Holter monitoring from the acute phase of the stroke was feasible with TWH. Following our protocol, only five patients were needed to screen to detected one case of AF.

Detection of atrial fibrillation using an earlobe photoplethysmographic sensor

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world, associated with increased risk of thromboembolic events and an increased mortality rate. In addition, a significant portion of AF patients are asymptomatic. Current AF diagnostic methods, often including a body surface electrocardiogram or implantable loop recorder, are both expensive and invasive and offer limited access within the general community. Objective: We tested the feasibility of the detection of AF using a photoplethysmographic signal acquired from an inexpensive, non-invasive earlobe photoplethysmographic sensor. This technology can be implemented into wearable devices and would enable continuous cardiac monitoring capabilities, greatly improving the rate of asymptomatic AF detection. Approach: We conducted a clinical study of patients going through electrical cardioversion for AF treatment. Photoplethysmographic recordings were taken from these AF patients before and after their cardioversion procedure, along with recordings from a healthy control group. Using these recordings, cardiac beats were identified and the inter-systolic interval was calculated. The inter-systolic interval was used to calculate four parameters to quantify the heart rate variability indicative of AF. Receiver operating characteristic curves were used to calculate discriminant thresholds between the AF and non-AF cohorts. Main results: The parameter with the greatest discriminant capability resulted in a sensitivity and specificity of 90.9%. These results are comparable to expensive ECG-based and invasive implantable loop recorder AF detection methods. Significance: These results demonstrate that using a non-invasive earlobe photoplethysmographic signal is a viable and inexpensive alternative to ECG-based AF detection methods, and an alternative that could be invaluable in detecting subclinical AF.

Incidence of Previously Undiagnosed Atrial Fibrillation Using Insertable Cardiac Monitors in a High-Risk Population

In approximately 20% of atrial fibrillation (AF)-related ischemic strokes, stroke is the first clinical manifestation of AF. Strategies are needed to identify and therapeutically address previously undetected AF. To quantify the incidence of AF in patients at high risk for but without previously known AF using an insertable cardiac monitor. This prospective, single-arm, multicenter study was conducted from November 2012 to January 2017. Visits took place at 57 centers in the United States and Europe. Patients with a CHADS2 score of 3 or greater (or 2 with at least 1 additional risk factor) were enrolled. Approximately 90% had nonspecific symptoms potentially compatible with AF, such as fatigue, dyspnea, and/or palpitations. Patients underwent monitoring with an insertable cardiac monitor for 18 to 30 months. The primary end point was adjudicated AF lasting 6 or more minutes and was assessed at 18 months. Other analyses included detection rates at points from 30 days to 30 months and among CHADS2 score subgroups. Median time from insertion to detection and the percentage of patients subsequently prescribed oral anticoagulation therapy was also determined. A total of 446 patients were enrolled; 233 (52.2%) were male, and the mean (SD) age was 71.5 (9.9) years. A total of 385 patients (86.3%) received an insertable cardiac monitor, met the primary analysis cohort definition, and were observed for a mean (SD) period of 22.5 (7.7) months. The detection rate of AF lasting 6 or more minutes at 18 months was 29.3%. Detection rates at 30 days and 6, 12, 24, and 30 months were 6.2%, 20.4%, 27.1%, 33.6%, and 40.0%, respectively. At 18 months, AF incidence was similar among patients with CHADS2 scores of 2 (24.7%; 95% CI, 17.3-31.4), 3 (32.7%; 95% CI, 23.8-40.7), and 4 or greater (31.7%; 95% CI, 22.0-40.3) (P = .23). Median (interquartile) time from device insertion to first AF episode detection was 123 (41-330) days. Of patients meeting the primary end point, 13 (10.2%) had 1 or more episodes lasting 24 hours or longer, and oral anticoagulation therapy was prescribed for 72 patients (56.3%). The incidence of previously undiagnosed AF may be substantial in patients with risk factors for AF and stroke. Atrial fibrillation would have gone undetected in most patients had monitoring been limited to 30 days. Further trials regarding the value of detecting subclinical AF and of prophylactic therapies are warranted. clinicaltrials.gov Identifier: NCT01727297.

Atrial fibrillation in retinal vascular occlusion disease and non-arteritic anterior ischemic optic neuropathy.

BackgroundPatients with retinal vascular occlusion disease have an increased risk for ischemic stroke and share some risk factors with cerebrovascular disease. The purpose of this study was to analyze the prevalence of atrial fibrillation (AF) in subjects with retinal vascular occlusive disease and anterior ischemic optic neuropathy and to compare these data to an ischemic stroke group.MethodsProspective, observational single-center trial. Subjects with retinal artery occlusion (RAO), retinal vein occlusion (RVO) and anterior ischemic optic neuropathy (AION) were included. Patients with ischemic stroke (IS) from a previous observational trial were used as control. Investigation included 7-day Holter ECG, echocardiography, duplex ultrasonography of the carotid arteries, and 24-hour blood pressure monitoring. Further vascular risk factors were documented.ResultsDuring the 1-year study period, 101 patients were recruited. The control group with ischemic stroke consisted of 272 subjects. At inclusion, the prevalence of AF was 12% (RAO), 10.2% (RVO), 11.1% (NAION) and 15.8% (IS). The final prevalence after Holter ECG rose to 16% (RAO), 18.4% (RVO), 14.8% (NAION) and 26.5% (IS). No significant difference was measured between groups.ConclusionsWe detected a similar prevalence of AF in all groups. RVO patients tended to exhibit a higher AF detection rate and lower number needed to screen than RAO and NAION. The detection of AF rose considerably via Holter ECG. As a consequence, we recommend prolonged ECG monitoring in patients with acute ophthalmic vascular diseases.

Long-term detection of atrial fibrillation with insertable cardiac monitors in a real-world cryptogenic stroke population

The long-term incidence of atrial fibrillation (AF) in cryptogenic stroke (CS) patients has been explored in carefully controlled clinical trials but real-world data are limited. We investigated the two-year incidence of AF in real-world clinical practice among a large cohort of patients with an insertable cardiac monitor (ICM) placed for AF detection following CS. Patients in the de-identified Medtronic Discovery™ Link database who received an ICM (Reveal LINQ™) for the purpose of AF detection following CS were included and monitored for up to 2years. All detected AF episodes (≥2min) were adjudicated. We quantified the AF detection rate using Kaplan-Meier survival estimates, analyzed the median time to initial detection of AF, and simulated the ability of various intermittent monitoring strategies to detect AF. A total of 1247 patients (65.3±13.0years, 53% male) were included and followed for 579±222days. AF episodes (n=4183) were detected in 238 patients, resulting in an AF detection rate of 21.5% at 2years. The median time to AF detection was 112 [IQR 35-293] days. Intermittent monitoring for AF detection was inferior to continuous ICM monitoring with sensitivities ranging from 2.9% (annual 24-hour Holter) to 29.9% (quarterly 7-day Holters), p<0.001. AF episodes were detected via continuous monitoring with ICMs in approximately 1 of every 5 CS patients within 2years of follow-up. The vast majority of patients with AF would not have been detected with conventional external ambulatory monitors. ICMs should therefore be considered in the evaluation of CS patients.

42 How hard do we look for atrial fibrillation?

Brief introductionIdentifying atrial fibrillation (AF) after ischaemic stroke changes the recommendation from antiplatelets to anticoagulation. Currently, there is no clear consensus on the duration of rhythm monitoring post stroke. EMBRACE...

Rationale and Design of the Randomized Controlled Trial of Intensive Versus Usual ECG Screening for Atrial Fibrillation in Elderly Chinese by an Automated ECG System in Community Health Centers in Shanghai (AF-CATCH)

Objective: The randomized controlled trial (ClinicalTrials.gov identifier NCT02990741) will investigate whether more frequent electrocardiographic (ECG) recordings and analyses with an automated ECG system would improve detection of atrial fibrillation compared with a single annual ECG screen in elderly Chinese in community health centers. Design: Men and women (≥65 years) will be randomized into intensive (n=3500) and usual (n=3500) screening groups, and within the intensive screening group into intensive screening (n=2625) and more intensive screening (n=875) subgroups. ECG recordings will be performed with an automated ECG analysis system (AliveCor® heart monitor) at 1 year in the usual screening group, at 3, 6, 9, and 12 months in the intensive screening subgroup, and at 1, 2, 3, and 4 weeks and 3, 6, 9, and 12 months in the more intensive screening subgroup. The primary outcome is the detection rate of atrial fibrillation between the usual screening group and the intensive screening group. Sample size estimation was based on a projected detection rate of atrial fibrillation of 2.0% by a single ECG recording at 12 months, an improvement of 50% with more frequent ECG recordings, a=0.05, power of 80%, and a one-sided test. Conclusions: The trial will provide evidence on the clinical effectiveness of more frequent ECG recordings by a handheld automated analysis system in the detection of atrial fibrillation.

Abstract 79: 30-Day Cardiac Monitoring is Feasible and Effective in a Community Setting

Prolonged cardiac rhythm monitoring reveals atrial fibrillation (AF) in 16-42% of patients who undergo monitoring for up to 6 months after a cryptogenic stroke. The feasibility of prolonged cardiac monitoring, AF detection rates and the impact of earlier screening after suspected cardioembolic infarct in a community setting is unknown. Methods: This prospective study examined patient compliance and AF detection rates with prolonged cardiac monitoring started within 30 days of a stroke/TIA. 181 patients ≥ 55 years old with a suspected cardioembolic stroke/TIA that occurred in the preceding 30 days were referred for 30-day cardiac monitoring. Patients were educated about reasons for monitoring and test procedures for 15-20 minutes. A Spiderflash-t or Northeast DR 200 monitor, programmed for detecting AF, was used. Auto-triggered and patient-activated recordings obtained during two consecutive 15-day monitoring periods were assessed. Either 3-day serial ECG or ≥24h Holter monitor was also completed in 119/181 patients. The primary outcome was patient compliance with 30 days of monitoring. Secondary outcomes included detection of any duration of AF within the two monitoring periods. Results: The compliance rate for the full 30-day monitoring period was 98.9% (179/181). AF was detected on 30-day monitor in 11.6% (21/181) of patients. Of the patients who received both 3-day serial ECG or ≥24h Holter and 30-day monitoring, AF was only detected in 0.84% (1/119) with 3-day serial ECG and/or Holter monitoring vs. 14.3% (17/119) with 30-day monitoring. AF was detected in 76.2% (16/21) of patients in the first 15 day period. 14 patients had AF lasting longer than 6 minutes, 5 had AF lasting between 30 secs - 6 min and 2 had AF &lt; 30 secs. Of patients who completed the 30-day monitoring, 38.8% had AF recurring through the 30 days. 85.7% (18/21) of patients were switched to a novel oral anticoagulant (NOAC), while 3 patients died and thus could not be switched to a NOAC. In conclusion, 30-day cardiac monitoring is feasible in a community setting with high compliance rates, yields similar AF detection rates as seen in clinical trials and positively impacts patient management. There are missed opportunities for secondary stroke prevention in the community without 30-day monitoring.