Atrial Fibrillation Monitoring Research Articles

Evaluation of Capacitive ECG for Unobtrusive Atrial Fibrillation Monitoring

Evaluation of Capacitive ECG for Unobtrusive Atrial Fibrillation Monitoring

Low Utility of Short-Term Rhythm Assessment Before Long-Term Rhythm Monitoring in Patients With Cryptogenic Stroke

Implantable cardiac monitors are routinely placed for long-term monitoring (LTM) after a period of negative short-term monitoring (STM) to increase atrial fibrillation (AF) detection after a cryptogenic stroke or transient ischemic attack (TIA). Optimizing AF monitoring after a cryptogenic stroke is critical to improve outcomes and reduce costs. We sought to compare the diagnostic yield of STM versus LTM, assess the impact of routine STM on hospitalization length of stay, and perform a financial analysis comparing the current model to a theoretical model wherein patients can proceed directly to LTM. Our retrospective observational cohort study analyzed patients admitted to Montefiore Medical Center between May 2017 and June 2022 with a primary diagnosis of cryptogenic stroke or TIA who underwent Holter device monitoring. Of 396 subjects, STM detected AF in 10 (2.5%) compared with a diagnostic yield of 14.6% for LTM (median time to diagnosis of 76days). Of the 386 patients with negative STM, 130 (33.7%) received an implantable cardiac monitor while an inpatient, and 256 (66.3%) did not. We calculated a point estimate of 1.67days delay of discharge attributable to the requirement for STM to precede LTM. Our model showed that the expected cost per patient in the STM-first paradigm is $28,615.33 versus $27,111.24 in the LTM-or-STM paradigm. Considering the relatively lower diagnostic yield of STM and its association with a longer length of stay and higher costs, it may be reasonable to proceed directly to LTM to optimize AF detection after a cryptogenic stroke or TIA.

Wearable Cardiac Rhythm Monitoring Device for Detection of Postoperative Atrial Fibrillation

PurposeThis study evaluated the use of a wearable, patch-based cardiac rhythm monitoring device in detecting postoperative atrial fibrillation (POAF) among cardiac surgical patients within 30 days after hospital discharge. DescriptionFrom the SEARCH-AF (The Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation) CardioLink-1 trial, this study examined rates of POAF according to surgery type and the incremental value of continuous cardiac rhythm monitoring among patients who underwent valve surgery. The primary outcome was cumulative atrial fibrillation or atrial flutter lasting for ≥6 minutes detected by continuous monitoring or atrial fibrillation or atrial flutter documented by a 12-lead electrocardiogram within 30 days of randomization. EvaluationThe primary outcome occurred in 8.2%, 13.5%, and 21.2% of patients who underwent isolated coronary artery bypass grafting (CABG), isolated valve surgery, and combined CABG and valve surgery. Relative to patients who underwent isolated CABG, those patients who had valve surgery were more likely to experience POAF. A higher diagnostic yield was obtained when the patch-based cardiac rhythm monitor was applied in patients who underwent valve surgery. ConclusionsUse of a wearable, patch-based cardiac monitoring device was an effective detection strategy among patients undergoing valve surgery, given their higher risk of developing POAF.

Value of morphological and laboratory markers in predicting the effectiveness of cryoballoon pulmonary vein isolation in atrial fibrillation

Aim. To determine the clinical, morphological, and biochemical pre­dictors of substrate-specific, non-vein-dependent atrial fibrillation (AF) by morphological and immunological examinations in patients with recurrent AF after pulmonary vein (PV) isolation.Material and methods. The study included 100 people (58 men and 42 women) with paroxysmal (n=89) and persistent (n=11) AF with a mean age of 58,2±9,4 years. After the primary operation, 15 people withdrew from the study due to refusal of reintervention, and 1 person withdrew due to suppuration of loop recorder bed and its explantation. A total of 100 patients underwent primary cryoballoon PV isolation with myocardial biopsy from the interventricular and interatrial septa, while 60 patients had subsequent hematoxylin-eosin and Van Gieson stains. Also, 100 patients were simultaneously implanted with ECG loop recorders for AF monitoring and blood was taken (before the intervention) for subsequent analysis of inflammation markers and antimyocardial antibodies. Patients underwent clinical observation during the year (visits after 3, 6, 12 months). Patients with relapses were referred for repeat electrophysiological examination and segmental ablation if PV ruptures were detected. After repeated intervention, the follow-up period was extended for a year with the same schedule of visits. According Two groups of patients were formed: without relapses (vein-dependent AF, group I) and with relapses (non-vein-dependent AF, group II), despite the achieved PV isolation as a result of 1 or 2 operations.Results. An analysis of morphological changes showed that an increase in AF recurrence risk by an average of 6,14 times (95% confidence interval: 1,14-47,6 (p=0,0462)) is associated with stage 2 interventricular septal fibrosis. Lymphocyte infiltration of the interventricular septum was associated with higher AF recurrence by an average of 9 times (95% confidence interval: 0,89-95,37) (p=0,0519).Among the laboratory parameters, a significantly higher concentration of the N-terminal pro-brain natriuretic peptide and a significantly lower concentration of antimyocardial antibodies were found in the group of patients with recurrent AF after LV isolation (p=0,0101).Conclusion. Inflammatory myocardium changes are an important link in the pathogenesis of AF and are associated with its recurrence.

Feasibility and safety of a single patch-based device for 30 days of continuous, uninterrupted ambulatory ecg monitoring

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): iRhythm Technologies, Inc. Background 14-day continuous ambulatory ECG monitoring (AEM) has been shown to have superior diagnostic yield to traditional 48-hour Holter monitoring for paroxysmal or undiagnosed atrial fibrillation and a wide range of clinical arrhythmias. 30-day recordings are typically from event recorders (non-continuous) and require frequent adhesive/electrode and battery replacement, all of which can impair patient compliance, wear time, and diagnostic yield. A new, uninterrupted patch-based AEM with next-generation breathable adhesive, storage, and battery life has received FDA clearance for 14-day wear. We evaluated the safety and feasibility of using this device for 30-days of continuous AEM. Methods We enrolled 30 participants with indications for AEM and applied a single Zio Monitor device for 30-days and analyzed wear time, analyzable time, and diagnostic yield, compared to with Zio Monitor 14-day use and with our standard, previous-generation product. Results In the cohort (76% female, 35% non-white, age 37±9 years, BMI 30.6±6.8), the median wear time was 29 continuous days (IQR 28-30) with no device changeouts and no clinically significant skin irritation. Although median analyzable times were high and similar across the previous (XT) and next-generation (Monitor) devices, the mean was significantly higher with Monitor, indicating fewer outliers that experienced premature termination of wear time. Arrhythmia yield (AF ≥30 sec, SVT ≥90 bpm & ≥4 bt, VT ≥100 bpm & ≥4 bt, inc PVT/TdP/VF, Pause ≥3 s, and/or AVB (any 2nd Deg or CHB) was significantly higher with the new Zio Monitor Device compared to Zio XT (80.9% vs 77.1%; p=0.017). Conclusion The application of a single, continuous, patch-based AEM for 30 days without adhesive (electrode) or battery replacement is feasible and safe. Analyzable time was high for 14-day and 30-day wear. The uninterrupted wear time and high compliance could lead to higher diagnostic yield than with traditional 30-day event recorders.

Active monitoring for atrial fibrillation (AMALFI): a streamlined randomised controlled trial of remote screening for subclinical atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health and Care Research Oxford Biomedical Research Centre ECG patches (and respective monitoring data analysis) were granted free of charge by the manufacturer (iRhythm) Background Incidence of stroke could be reduced by detection of subclinical atrial fibrillation (AF) and appropriate anticoagulation. Opportunistic screening by pulse-taking or ECG is recommended by some international guidelines. In contrast, there is uncertainty regarding the benefits and harms of systematic screening across populations and/or using longer monitoring durations. Purpose To assess if screening using a one-off single-lead continuous non-invasive ECG patch worn for 14 days increases AF detection at 2.5 years compared to standard care, and whether this approach is cost-effective. Methods AMALFI is an ongoing mail-based open-label randomised controlled trial of remote AF screening in England. Streamlined design includes integration with national electronic health data and care pathways for participant identification, invitation, and management. The target population are individuals aged ≥65 years with CHA2DS2VASc score of ≥3 in men and ≥4 in women, and with no prior history of AF or allergy to latex. Participants in the intervention arm self-apply the ECG patch and return it for analysis after 14 days. AF findings (duration ≥30 seconds at any rate) are communicated to primary care physicians, with further clinical management at their discretion. Participants in the control arm receive usual care (which is expected to include opportunistic AF screening). The primary outcome is the proportion of participants with newly-detected AF recorded in primary care electronic health records in each group at 2.5 years after randomisation. Results From 2019 to 2022, AMALFI invited 22,188 people, of whom 5,040 (23%) were randomised. Baseline characteristics included age 77±6 years, 47% female, and median CHA2SD2VASc score 3 (Table 1). Of 2520 individuals randomised to the intervention, 2127 (84%) wore and returned the patch. Median wear time was 13.9 days and median proportion of time analysable was 98.8%. AF was present in 102 patch reports, representing 4.8% of reports received and 4% of the intervention arm (in line with a priori estimates for power calculations for the primary outcome); median AF burden was 11.3%. AF was present at commencement of recording in 40% of these reports, by the end of the first day in 58%, and by the end of the first week in 83% (Figure 1). Incidental findings included supraventricular tachycardia (in 90% of reports), non-sustained ventricular tachycardia (VT; in 32%), sustained VT (in 0.1%), Mobitz II/high-grade/3rd degree AV block (in 1.1%), and pauses >6s (in 0.3%). Conclusion AMALFI’s innovative design facilitated recruitment and demonstrates that a remote ECG patch-based AF screening strategy is feasible, resulting in a new diagnosis of AF in ~4% of individuals selected due to moderate-to-high clinical stroke risk. Longer term follow-up will provide data on the incremental value and cost-effectiveness of AF diagnosis by systematic screening compared to routine opportunistic detection.

LB-456091-2 DYNAMIC DATA DRIVEN MANAGEMENT OF ATRIAL FIBRILLATION USING IMPLANTABLE CARDIAC MONITORS – THE MONITOR AF STUDY

Management of atrial fibrillation (AF) is often complex and dynamic. Clinical decisions related to initiation of rate control, rhythm control strategies, stroke prophylaxis measures depend on the assessment of the presence and the burden of AF. Assessment of therapy outcomes and withdrawl of drugs and anticoagulation are guided by AF monitoring. Implantable cardiac monitors (ICM) are excellent tools to detect and monitor AF burden in a dynamic fashion. We prospectively studied if the presence of an ICM impacts the management of AF and there by clinical outcomes.

Anxiety, patient activation, and quality of life among stroke survivors prescribed smartwatches for atrial fibrillation monitoring

The detection of atrial fibrillation (AF) in stroke survivors is critical to decreasing the risk of recurrent stroke. Smartwatches have emerged as a convenient and accurate means of AF diagnosis; however, the impact on critical patient-reported outcomes, including anxiety, engagement, and quality of life, remains ill defined. To examine the association between smartwatch prescription for AF detection and the patient-reported outcomes of anxiety, patient activation, and self-reported health. We used data from the Pulsewatch trial, a 2-phase randomized controlled trial that included participants aged 50 years or older with a history of ischemic stroke. Participants were randomized to use either a proprietary smartphone-smartwatch app for 30 days of AF monitoring or no cardiac rhythm monitoring. Validated surveys were deployed before and after the 30-day study period to assess anxiety, patient activation, and self-rated physical and mental health. Logistic regression and generalized estimation equations were used to examine the association between smartwatch prescription for AF monitoring and changes in the patient-reported outcomes. A total of 110 participants (mean age 64 years, 41% female, 91% non-Hispanic White) were studied. Seventy percent of intervention participants were novice smartwatch users, as opposed to 84% of controls, and there was no significant difference in baseline rates of anxiety, activation, or self-rated health between the 2 groups. The incidence of new AF among smartwatch users was 6%. Participants who were prescribed smartwatches did not have a statistically significant change in anxiety, activation, or self-reported health as compared to those who were not prescribed smartwatches. The results held even after removing participants who received an AF alert on the watch. The prescription of smartwatches to stroke survivors for AF monitoring does not adversely affect key patient-reported outcomes. Further research is needed to better inform the successful deployment of smartwatches in clinical practice.

A study of the effects of intravenous magnesium sulphate on post-operative atrial fibrillation in patients undergoing off pump coronary artery bypass grafting (CABG)

Atrial fibrillation (AF) occurs in almost 30% of patients undergoing coronary artery bypass grafting (CABG). Around 80% of these patients have decreased levels of total and ionized serum magnesium postoperatively. The association between magnesium deficiency and post CABG AF is still undetermined. Therefore, a large variety of prophylactic strategies have been assessed including perioperative magnesium administration. However, the efficacy is still questionable. The aim of this study was to find out any correlation of serum magnesium levels with the incidence of post-operative atrial fibrillation in patients undergoing off pump CABG and whether magnesium supplementation modifies the incidence. One hundred fifty patients undergoing CABG were selected and divided into treatment and control groups. Perioperative serum magnesium assays were done, and patients were monitored in the postoperative period for occurrence of Atrial Fibrillation. The risk of post CABG atrial fibrillation was more among females, obese patients, patients with EF < 50% and RWMA. Post-operative AF occurred in 5 patients in the treatment group (n = 75) and 11 patients in the control group (n = 75). : The proportion of patients with post-operative atrial fibrillation among cases (6.7%) was lower than that of controls (14.7%) which may indicate an important role of magnesium in prevention of AF following cardiac surgeries. The results however didn’t reach a statistical significance which could be due to sample size, the duration and design of the study and the period of post-operative AF monitoring.

Prevalence and Prognostic Significance of Bradyarrhythmias in Patients Screened for Atrial Fibrillation vs Usual Care

There is increasing interest in heart rhythm monitoring and technologies to detect subclinical atrial fibrillation (AF), which may lead to incidental diagnosis of bradyarrhythmias. To assess bradyarrhythmia prevalence and prognostic significance in persons screened for AF using implantable loop recorder (ILR) compared with unscreened persons. This was a post hoc analysis of the Implantable Loop Recorder Detection of Atrial Fibrillation to Prevent Stroke (LOOP) randomized clinical trial, which took place in 4 sites in Denmark. Participants were 70 years or older without known AF but diagnosed with at least 1 of the following: hypertension, diabetes, heart failure, or prior stroke. Participants were recruited by letter invitation between January 31, 2014, and May 17, 2016. The median (IQR) follow-up period was 65 (59-70) months. Analysis took place between February and June 2022. ILR screening for AF with treatment of any bradyarrhythmia left to the discretion of the treating physician (ILR group) vs usual care (control group). Adjudicated bradyarrhythmia episodes, pacemaker implantation, syncope, and sudden cardiovascular death. A total of 6004 participants were randomized (mean [SD] age, 75 [4.1] years; 2837 [47.3%] female; 5444 [90.7%] with hypertension; 1224 [20.4%] with prior syncope), 4503 to control and 1501 to ILR. Bradyarrhythmia was diagnosed in 172 participants (3.8%) in the control group vs 312 participants (20.8%) in the ILR group (hazard ratio [HR], 6.21 [95% CI, 5.15-7.48]; P < .001), and these were asymptomatic in 41 participants (23.8%) vs 249 participants (79.8%), respectively. The most common bradyarrhythmia was sinus node dysfunction followed by high-grade atrioventricular block. Risk factors for bradyarrhythmia included higher age, male sex, and prior syncope. A pacemaker was implanted in 132 participants (2.9%) vs 67 (4.5%) (HR, 1.53 [95% CI, 1.14-2.06]; P < .001), syncope occurred in 120 (2.7%) vs 33 (2.2%) (HR, 0.83 [95% CI, 0.56-1.22]; P = .34), and sudden cardiovascular death occurred in 49 (1.1%) vs 18 (1.2%) (HR, 1.11 [95% CI, 0.64-1.90]; P = .71) in the control and ILR groups, respectively. Bradyarrhythmias were associated with subsequent syncope, cardiovascular death, and all-cause death, with no interaction between bradyarrhythmia and randomization group. More than 1 in 5 persons older than 70 years with cardiovascular risk factors can be diagnosed with bradyarrhythmias when long-term continous monitoring for AF is applied. In this study, ILR screening led to a 6-fold increase in bradyarrhythmia diagnoses and a significant increase in pacemaker implantations compared with usual care but no change in the risk of syncope or sudden death.

A Smartwatch System for Continuous Monitoring of Atrial Fibrillation in Older Adults After Stroke or Transient Ischemic Attack: Application Design Study.

The prevalence of atrial fibrillation (AF) increases with age and can lead to stroke. Therefore, older adults may benefit the most from AF screening. However, older adult populations tend to lag more than younger groups in the adoption of, and comfort with, the use of mobile health (mHealth) apps. Furthermore, although mobile apps that can detect AF are available to the public, most are designed for intermittent AF detection and for younger users. No app designed for long-term AF monitoring has released detailed system design specifications that can handle large data collections, especially in this age group. This study aimed to design an innovative smartwatch-based AF monitoring mHealth solution in collaboration with older adult participants and clinicians. The Pulsewatch system is designed to link smartwatches and smartphone apps, a website for data verification, and user data organization on a cloud server. The smartwatch in the Pulsewatch system is designed to continuously monitor the pulse rate with embedded AF detection algorithms, and the smartphone in the Pulsewatch system is designed to serve as the data-transferring hub to the cloud storage server. We implemented the Pulsewatch system based on the functionality that patients and caregivers recommended. The user interfaces of the smartwatch and smartphone apps were specifically designed for older adults at risk for AF. We improved our Pulsewatch system based on feedback from focus groups consisting of patients with stroke and clinicians. The Pulsewatch system was used by the intervention group for up to 6 weeks in the 2 phases of our randomized clinical trial. At the conclusion of phase 1, 90 trial participants who had used the Pulsewatch app and smartwatch for 14 days completed a System Usability Scale to assess the usability of the Pulsewatch system; of 88 participants, 56 (64%) endorsed that the smartwatch app is "easy to use." For phases 1 and 2 of the study, we collected 9224.4 hours of smartwatch recordings from the participants. The longest recording streak in phase 2 was 21 days of consecutive recordings out of the 30 days of data collection. This is one of the first studies to provide a detailed design for a smartphone-smartwatch dyad for ambulatory AF monitoring. In this paper, we report on the system's usability and opportunities to increase the acceptability of mHealth solutions among older patients with cognitive impairment. ClinicalTrials.gov NCT03761394; https://www.clinicaltrials.gov/ct2/show/NCT03761394. RR2-10.1016/j.cvdhj.2021.07.002.

Abstract WP215: Increase In CD11b Positive Inflammatory Cells In Cardioembolic And Cryptogenic Strokes: A Study Of Thrombi From Stroke Patients

Introduction: Around 25-40% of ischemic strokes are cryptogenic or strokes of undetermined etiology. Determination of stroke etiology can be challenging, requiring extensive diagnostic testing including long term monitoring for occult atrial fibrillation. Recent studies suggest that inflammation (monocytes/ macrophages driven) and fibrosis in the atrial substrate leads to atrial fibrillation/ cardioembolic strokes. Therefore, we hypothesized that clots collected from patients with cardioembolic stroke during thrombectomy will have increased myeloid derived inflammatory cells as compared to other stroke etiologies. Methods: 54 thrombi were obtained during mechanical thrombectomy in patients with ischemic strokes after consent. They were formalin fixed, embedded, sliced and stained with CD11b, a marker for myeloid derived cells and some lymphoid cells. Mean of five 20x images from two slices per patient was quantified by image J and used for analysis. The relationship between stroke etiology (TOAST) and number of CD11b positive cells was assessed using Mann-Whitney U test and multilinear regression models. Results: Mean patient age was 64.2±12.5 years, 33.3% were women, 81.5% had hypertension, 22.2% had diabetes mellitus, and 37% had hyperlipidemia. Thrombi with cardioembolic etiology had significantly higher number of CD11b positive cells (248.2±137.4, n=27) as compared to strokes from large artery atherosclerosis (133.3±95.7, n=11), p=0.02. Cryptogenic strokes also had significantly higher number of CD11b positive cells, (212.1± 104.8, n=13) when compared to strokes from large artery atherosclerosis, p=0.04, n=11, even after controlling for hypertension, hyperlipidemia, heart disease, diabetes mellitus and age. No difference was seen in CD11b positive cell numbers between cardioembolic and cryptogenic strokes, p=0.4. Conclusion: Cardioembolic and cryptogenic stroke thrombi have increased CD11b positive cells as compared to strokes from large artery atherosclerosis. The shared histology of cardioembolic and cryptogenic strokes suggests that many of the cryptogenic strokes may be due to undiagnosed cardioembolism. Future studies using flow cytometry on thrombi can be a novel area of research for stroke etiology.

Abstract 31: The ATTICUS Randomized Controlled Trial - Subgroup Analyses

Background: ATTICUS is the third prospective randomized controlled trial that compared a direct oral anticoagulant (DOAC) vs. acetylsalicylic acid (ASA) for secondary prevention after embolic stroke of undetermined source (ESUS). Aim of ATTICUS was to determine whether apixaban, initiated within 28 days after ESUS, is superior to ASA in preventing new ischemic lesions on 12-month follow- up MRI (primary endpoint) in subjects with remote atrial fibrillation (AF) monitoring. Methods: Multicenter (14 German centers) open-label randomized (1:1) controlled trial with blinded endpoint assessment. ESUS patients with at least one risk factor for AF/cardiac thromboembolism (i.e., left atrium (LA) size &gt; 45 mm, spontaneous echo contrast in LA appendage, LA appendage flow velocity ≤ 0.2 m/s, atrial high-rate episodes, CHA2DS2-VASc ≥ 4, patent foramen ovale (PFO)) were enrolled. Study drug was initiated 3 to 28 days after minor/moderate stroke and ≥ 14 to 28 days after major stroke. ClinicalTrials.gov: NCT02427126. Funding by Bristol Meyers Squibb-Pfizer Alliance (Euro 2.2 Mio.) and Medtronic. Results: 352 patients were available for final analysis. New ischemic lesion(s) were found in 13.6% vs. 16.0% of patients in the apixaban and the ASA arm, respectively (p=0.57), intention-to-treat. AF was detected in 25.6 % of patients. No difference between study arms was found for other thromboembolism, death, SAE, major and clinically relevant bleeds. Conclusions: ATTICUS was the first trial testing the concept of DOAC vs. ASA in an enriched ESUS population. Mandatory cardiac monitoring, vessel imaging, and MRI in all ATTICUS patients will help to better understand this complex condition. We will present secondary analyses including on-treatment analysis, prevention of embolic/disabling lesions/strokes, association of stroke pattern with AF occurrence/macroangiopathic changes.

Atrial Fibrillation Monitoring Based on Noncontact Capacitive ECG Using an Integrated Microhumidity Fabric Electrode-Sheet Sensing Scheme

This study designed a novel noncontact capacitive Electrocardiogram (cECG) system for long-term atrial fibrillation (AF) monitoring. Unlike conventional ECG monitoring, the proposed system can record ECG signals without touching a subject’s skin, avoiding the problem of skin allergy by using wet electrodes. The main contributions of this study include the two aspects. Firstly, a noncontact electrode based on a micro-humidity fabric structure is proposed, which can improve the noncontact cECG signal quality. Secondly, based on the proposed electrode, the possibility of its application in long-term AF monitoring was investigated. The micro-humidity fabric electrode can improve the micro-humidity of the skin-electrode interface and the noncontact cECG signal quality. This humidity is low and can hardly be felt by the human body, which can also ensure comfort. The experimental results show that compared with the conventional noncontact fabric electrode, the skin-electrode impedance decreases from 104.1±58.1 MΩ (when using the electrode without the micro-humidity structure) at 0.5 Hz to 2.8±1.79 MΩ (with the micro-humidity structure). In the long-term cECG recording experiment, the system has high consistency with the reference equipment. The RR interval correlation coefficient is 0.998, and the maximum error ≤ 18 ms. For the validation of AF monitoring, a designed AF analysis algorithm is integrated into the noncontact cECG system, including effective signal screening and AF recognition algorithm based on RR interval and SVM, with an average accuracy of 98.57% on the wearable database. The algorithm is verified on 3 healthy people and 1 PAF patient using the noncontact cECG system with an average accuracy of 98.12%, showing that our system has the potential for long-term AF monitoring.

New atrial arrhythmia occurrence in single chamber implantable cardioverter defibrillator patients: A real-world investigation.

A current limitation of single chamber implantable cardioverter defibrillators (ICDs) is the lack of an atrial lead to reliably detect atrial fibrillation (AF) episodes. A novel ventricular based atrial fibrillation (VBAF) detection algorithm was created for single chamber ICDs to assess R-R variability for detection of AF. Patients implanted with Visia AF™ ICDs were prospectively enrolled in the Medtronic Product Surveillance Registry from December 15, 2015 to January 23, 2019 and followed with at least 30 days of monitoring with the algorithm. Time to device-detected daily burden of AF ≥ 6 min, ≥6 h, and ≥23 h were reported. Clinical actions after device-detected AF were recorded. A total of 291 patients were enrolled with a mean follow-up of 22.5 ± 7.9 months. Of these, 212 (73%) had no prior history of AF at device implant. However, 38% of these individuals had AF detected with the VBAF algorithm with daily burden of ≥6 min within two years of implant. In these 80 patients with newly detected AF by their ICD, 23 (29%) had a confirmed clinical diagnosis of AF by their provider. Of patients with a clinical diagnosis of AF, nine (39%) were newly placed on anticoagulation, including five of five (100%) patients having a burden >23 h. Continuous AF monitoring with the new VBAF algorithm permits early identification and actionable treatment for patients with undiagnosed AF that may improve patient outcomes.

The Impact of Statins on Postdischarge Atrial Fibrillation After Cardiac Surgery: Secondary Analysis from a Randomized Trial

BackgroundWhether statins reliably reduce the risk of postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery remains controversial. We sought to determine the impact of statin use on new-onset postdischarge POAF in the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized controlled trial. MethodsWe randomized 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥ 2) and no history of preoperative atrial fibrillation (AF) to 30-day continuous cardiac rhythm monitoring after discharge from cardiac surgery with a wearable, patched-based device or to usual care. The primary endpoint was the occurrence of cumulative AF and/or atrial flutter lasting for ≥ 6 minutes detected by continuous monitoring, or AF and/or atrial flutter documented by a 12-lead electrocardiogram within 30 days of randomization. ResultsThe 260 patients (77.4%) discharged on statins were more likely to be male (P = 0.018) and to have lower CHA2DS2-VASc scores (P = 0.011). Patients treated with statins at discharge had a 2-fold lower rate of POAF than those who were not treated with statins in the entire cohort (18.4% vs 8.1%, log-rank P = 0.0076). On multivariable Cox regression including the CHA2DS2-VASc score adjustment, statin use was associated with a lower risk of POAF (hazard ratio 0.43, 95% confidence interval: 0.25-0.98, P = 0.043). Use of statins at a higher intensity was associated with lower risk of POAF, suggestive of a dose–response effect (log-rank Ptrend = 0.0082). ConclusionsThe use of statins was associated with a reduction in postdischarge POAF risk among patients undergoing cardiac surgery. The routine use of high-intensity statin to prevent subacute POAF after discharge deserves further study.

14-day Holter monitoring for atrial fibrillation after ischemic stroke: The yield of guideline-recommended monitoring duration.

Current European Stroke Organisation (ESO) guidelines recommend >48 h of continuous electrocardiographic monitoring for atrial fibrillation (AF) in all patients with ischemic stroke or transient ischemic attack (TIA) with undetermined origin. We assessed the yield of the guideline-recommended monitoring for AF, as well as of extending monitoring up to 14 days. We included consecutive patients with stroke/TIA without AF in an academic hospital in The Netherlands. We reported AF incidence and number needed to screen (NNS) in the overall sample after 48 h and 14 days of Holter monitoring. Among 379 patients with median age 63 years (IQR 55-73), 58% male, Holter monitoring detected 10 cases of incident AF during a median of 13 (IQR 12-14) days of monitoring. Seven AF cases were detected within the first 48 hours (incidence 1.85%, 95% CI 0.74-3.81; NNS 54), and three additional AF cases were recorded among the 362 patients with >48 h of monitoring and without AF ⩽ 48 h (incidence 0.83%, 95% CI: 0.17-2.42; NNS 121). All AF cases were detected within the first 7 days of monitoring. Our sample was subject to sampling bias favoring inclusion of participants with low AF risk. Strengths of this work were the broad inclusion criteria as recommended by ESO guidelines, and high Holter adherence among participants. The analysis was limited by inclusion of lower-risk cases and a relatively small sample size. In low-risk patients with recent stroke or TIA, ESO guideline-recommended screening for AF resulted in a low AF yield, with limited additional value of monitoring up to 14 days. Our results underline the need for a personalized approach in determining a patient's optimum duration for post-stroke non-invasive ambulatory monitoring.

Evaluation of Huawei smart wearables for detection of atrial fibrillation in patients following ischemic stroke: The Liverpool-Huawei stroke study

Atrial fibrillation (AF) often remains undetected following stroke. Documenting AF is critical to initiate oral anticoagulation, which has proven benefit in reducing recurrent stroke and mortality in patients with AF. The accuracy and acceptability of using smart wearables to detect AF in patients following stroke is unknown. The aims of the Liverpool-Huawei Stroke Study are to determine the effectiveness, cost-effectiveness and patient and staff acceptability of using Huawei smart wearables to detect AF following ischemic stroke. The study plans to recruit 1,000 adults aged ≥18 years following ischemic stroke from participating hospitals over 12 months. All participants will be asked to wear a Huawei smart band for 4 weeks postdischarge. If participants do not have access to a compatible smartphone required for the study, they will be provided with a smartphone for the 4-week AF monitoring period. Participants with suspected AF detected by the smart wearables, without previous known AF, will be referred for further evaluation. To determine the effectiveness of the Huawei smart wearables to detect AF, the positive predictive value will be determined. Patient acceptability of using this technology will also be examined. Additional follow-up assessments will be conducted at 6 and 12 months, and clinical outcomes recorded in relation to prevalent and incident AF post-stroke. The study opened for recruitment on May 30, 2022, and is currently open at 4 participating hospitals; the first 106 participants have been recruited. One further hospital is preparing to open for recruitment. This prospective study will examine the effectiveness and acceptability of the use of smart wearables in patients following ischemic stroke. This could have important implications for detection of AF and therefore, earlier prophylaxis for recurrent stroke. The study is registered on https://www.isrctn.com/ (Identifier ISRCTN30693819).

Diagnostic yield of an insertable cardiac monitor in a large patient population

Insertable cardiac monitors (ICMs) are increasingly used for cardiac rhythm diagnosis with expanding indications. Little has been reported about their use and efficacy. The study sought to evaluate the clinical utility of a novel ICM (Biotronik BIOMONITOR III) including the time to diagnosis in unselected patients with different ICM indications. Patients from 2 prospective clinical studies were included to determine the diagnostic yield of the ICM. The primary endpoint was time to clinical diagnosis per implant indication or to the first change in atrial fibrillation (AF) therapy. A total of 632 patients were included with a mean follow-up of 233 ± 168 days. Of 384 patients with (pre)syncope, 34.2% had a diagnosis at 1 year. The most frequent therapy was permanent pacemaker implantation. Of 133 patients with cryptogenic stroke, 16.6% had an AF diagnosis at 1 year, resulting in oral anticoagulation. Of 49 patients with an indication for AF monitoring, 41.0% had a relevant change in AF therapy based on ICM data at 1 year. Of 66 patients with other indications, 35.4% received a rhythm diagnosis at 1 year. Moreover, 6.5% of the cohort had additional diagnoses: 26 of 384 patients with syncope, 8 of 133 patients with cryptogenic stroke, and 7 of 49 patients with AF monitoring. In a large unselected patient population with heterogeneous ICM indications, the primary endpoint of rhythm diagnosis was achieved in ∼1 in 4, and additional clinically relevant findings was achieved in 6.5% of patients at short-term follow-up.

Abstract 11437: False Atrial Fibrillation Alerts From Smartwatch in Relation to Perceived Physical Well-Being and Confidence in Management of Chronic Symptoms: The Pulsewatch Study

Background: Atrial fibrillation (AF) can cause strokes that may be preventable with timely detection and anticoagulation therapy. Smartwatches offer the potential for non-invasive, long-term AF monitoring, but potential implications for psychological well-being associated with these alert systems remain to be studied. We examined the psychosocial impact of false alerts for AF on patients prescribed a smartwatch post stroke. Methods: We analyzed data from the Pulsewatch study (NCT03761394), which enrolled patients ≥50 years from the UMass Memorial Health system who had a history of stroke or transient ischemic attack, CHA 2 DS 2 -VASc ≥2, and no contraindications to anticoagulation. Data from participants in the intervention group, who received a cardiac patch monitor, as well as a smartwatch and smartphone installed with Pulsewatch applications, were analyzed. At baseline and 14 days, participants completed the Health Survey SF-12 to assess perceived physical well-being, and the Symptom Management survey to assess confidence in disease self-management. We employed logistic regression to assess changes in anxiety, perceived mental and physical health, and chronic disease management self-efficacy over 14 days with exposure to false alerts. Results: Among 85 participants who received a smartwatch for AF detection (mean age 64.8±9.2 years, 41% female, 86% non-Hispanic white) 11 (13%) received a false AF alert. Receipt of false alerts was associated with significant decreases in perceived physical well-being and management of chronic symptoms (β = -9.08, p &lt; 0.01 and β = -6.50, p = 0.03, respectively), but not significantly associated with changes in perceived mental health (β = 0.70, p = 0.78). Conclusions: Perceived physical well-being and levels of disease self-management, but not perceived mental health, decreased with exposure to false AF alarms over 14 days. Further studies are required to explore the psychological impact of smartwatch AF monitoring in patients post stroke.