Potential Cost-Effectiveness of Ambulatory Cardiac Rhythm Monitoring After Cryptogenic Stroke

Enhanced diagnostic workup increases pathological findings in patients with acute ischaemic stroke: results of the prospective HEBRAS study

BACKGROUND

Stroke aetiology remains cryptogenic in a relevant proportion of patients with acute ischaemic stroke (AIS). We assessed whether enhanced diagnostic workup after AIS yields a higher rate of prespecified pathological findings compared with routine diagnostic care in-hospital.

METHODS

Hospitalised patients with AIS were prospectively enrolled in the investigator-initiated observational HEart and BRain Interfaces in Acute Ischaemic Stroke (HEBRAS) study at the Charité, Berlin, Germany. Patients with AIS without known atrial fibrillation (AF) underwent cardiovascular MR imaging (CMR), MR-angiography of the aortic arch and prolonged Holter-ECG monitoring on top of routine diagnostic care.

RESULTS

Among 356 patients with AIS (mean age 66 years, 37.6% female), enhanced workup yielded a higher rate of prespecified pathological findings compared with routine care (17.7% vs 5.3%; p<0.001). Consequently, fewer patients were classified as cryptogenic after enhanced diagnostic workup (38.5% vs 45.5%, p<0.001). Routine care included echocardiography in 228 (64.0%) patients. CMR was successfully performed in 292 (82.0%) patients and revealed more often a prespecified pathological finding compared with routine echocardiography (16.1% vs 5.3%). Furthermore, study-related ECG monitoring (median duration 162 hours (IQR 98-210)) detected AF in 16 (4.5%) patients, while routine monitoring (median duration 51 hours (IQR 34-74)) detected AF in seven (2.0%) patients.

CONCLUSIONS

Enhanced diagnostic workup revealed a higher rate of prespecified pathological findings in patients with AIS compared with routine diagnostic care and significantly reduced the proportion of patients with cryptogenic stroke.

TRIAL REGISTRATION NUMBER

NCT02142413.

Role of the score for the targeting of atrial fibrillation (STAF) combined with D-dimer in screening ischemic stroke patients with atrial fibrillation

Background

We aim to explore the effect of the score for the targeting of atrial fibrillation (STAF) combined with the serum D-dimer (DD) level in screening acute ischemic stroke patients with atrial fibrillation (AF).

Methods

This study is a retrospective case observation study. This study consecutively selected patients with acute ischemic stroke who were hospitalized in the Department of Neurology at Zhuhai Hospital Affiliated with Jinan University from February 2019 to February 2021. Venous blood was drawn from all patients within 24 hours of hospitalization for DD detection. In accordance with the medical records, the patients were classified into an AF group and a non-AF group and were scored according to the STAF standard. A combined test method was used to estimate the diagnostic screening value of the STAF combined with the DD value for acute ischemic stroke patients with AF.

Detection of atrial fibrillation using an implantable loop recorder in patients with previous cryptogenic stroke: the SPIDER-AF registry (Stroke Prevention by Increasing DEtection Rates of Atrial Fibrillation)

BACKGROUND

The use of implantable loop recorder (ILR) to detect atrial fibrillation (AF) in patients with a history of cryptogenic stroke (CS) has seldom been investigated in "real-world" settings.

OBJECTIVE

This study aimed to present the results of the Stroke Prevention by Increasing DEtection Rates of Atrial Fibrillation (SPIDER-AF) registry.

METHOD

SPIDER is a multicentric, observational registry, including 35 facilities all over Germany. It enrolled outpatients without AF history and with CS before ILR implantation.

RESULTS

We included 500 patients (mean age 63.1 ± 12.7 years), 304 (60.8%) were males, with previous stroke (72.6%) and TIA (27.4%). After inclusion, all were followed for at least 12 months. AF was detected in 133 (26.8%), 25.3% of patients with previous stroke and 29.9% with TIA (p = 0.30). AF was detected after a median of 121.5 days (IQR 40.5-223.0). AF was primarily paroxysmal (95.7% after stroke, 100% after TIA). In 19.5% (n = 26) anticoagulation was not administered after AF detection. Mean CHA2DS2-VASc score (OR 1.22; CI 1.01-1.49; p = 0.037) and age > 70 years (OR 0.41; CI 0.19-0.88; p = 0.0020) correlated with AF. Repeat cerebrovascular events at follow-up (28; 5.6%) correlated with AF (OR = 2.17; CI 1.00-4.72; p = 0.049). AF (p = 0.91) and recurrent events (p = 0.43) occurred similarly in females and males.

CONCLUSIONS

In the context of cryptogenic strokes ILRs are a valuable tool for early detection of AF. In a real-world scenario, the anticoagulation therapy remains inadequate despite diagnosed AF in a relevant subset of patients requiring optimization of patient management.

Embolic Stroke of Undetermined Source: Current Perspectives on Diagnosis, Investigations, and Management

In 2014, Hart et al. introduced the concept of "embolic stroke of undetermined source" (ESUS) to the clinical-research stroke community. The hypothesis underlying the development of the ESUS construct was that this potentially heterogenous group of stroke mechanisms were largely thromboembolic, and would thus benefit from anticoagulation over antiplatelet for secondary prevention. Since then, 2 large clinical trials have shown that, to date, there is not a clear uniform antithrombotic strategy for secondary prevention after ESUS as it was originally broadly defined. However, this work has yielded valuable information about the patient phenotypes that experience ESUS strokes, as well as hypothesis-generating substudies that have given rise to the next generation of secondary prevention trials aimed at more personalized approaches for different suspected mechanisms of embolic stroke. In parallel with the evolution of ESUS, several studies aimed at screening for atrial fibrillation in the secondary stroke prevention population have generated additional questions about the mechanistic relevance of atrial fibrillation detected after stroke, and how this should inform poststroke workup, and secondary prevention strategies. Herein, we provide a synthesis of the current understanding surrounding the patient phenotypes that experience ESUS strokes, and previous, ongoing, and anticipated clinical trials that will guide earlier and later secondary prevention strategies and poststroke cardiac investigations.

Clinical applications of heart rhythm monitoring tools in symptomatic patients and for screening in high-risk groups

Recent technological advances have facilitated and diversified the options available for the diagnosis of cardiac arrhythmias. Ranging from simple resting or exercise electrocardiograms to more sophisticated and expensive smartphones and implantable cardiac monitors. These tests and devices may be used for varying periods of time depending on symptom frequency. The choice of the most appropriate heart rhythm test should be guided by clinical evaluation and optimized following accurate characterization of underlying symptoms, 'red flags', risk factors, and consideration of cost-effectiveness of the different tests. This review provides evidence-based guidance for assessing suspected arrhythmia in patients who present with symptoms or in the context of screening, such as atrial fibrillation or advanced conduction disturbances following transcatheter aortic valve implantation in high-risk groups. This is intended to help clinicians choose the most appropriate diagnostic tool to facilitate the management of patients with suspected arrhythmias.

Left Atrial Appendage Occlusion Versus Oral Anticoagulation in Atrial Fibrillation : A Decision Analysis

BACKGROUND

Left atrial appendage occlusion (LAAO) is a potential alternative to oral anticoagulants in selected patients with atrial fibrillation (AF). Compared with anticoagulants, LAAO decreases major bleeding risk, but there is uncertainty regarding the risk for ischemic stroke compared with anticoagulation.

OBJECTIVE

To determine the optimal strategy for stroke prevention conditional on a patient's individual risks for ischemic stroke and bleeding.

DESIGN

Decision analysis with a Markov model.

DATA SOURCES

Evidence from the published literature informed model inputs.

TARGET POPULATION

Women and men with nonvalvular AF and without prior stroke.

TIME HORIZON

Lifetime.

PERSPECTIVE

Clinical.

INTERVENTION

LAAO versus warfarin or direct oral anticoagulants (DOACs).

OUTCOME MEASURES

The primary end point was clinical benefit measured in quality-adjusted life-years.

RESULTS OF BASE-CASE ANALYSIS

The baseline risks for stroke and bleeding determined whether LAAO was preferred over anticoagulants in patients with AF. The combined risks favored LAAO for higher bleeding risk, but that benefit became less certain at higher stroke risks. For example, at a HAS-BLED score of 5, LAAO was favored in more than 80% of model simulations for CHA₂DS₂-VASc scores between 2 and 5. The probability of LAAO benefit in QALYs (>80%) at lower bleeding risks (HAS-BLED score of 0 to 1) was limited to patients with lower stroke risks (CHA₂DS₂-VASc score of 2). Because DOACs carry lower bleeding risks than warfarin, the net benefit of LAAO is less certain than that of DOACs.

RESULTS OF SENSITIVITY ANALYSIS

Results were consistent using the ORBIT bleeding score instead of the HAS-BLED score, as well as alternative sources for LAAO clinical effectiveness data.

LIMITATION

Clinical effectiveness data were drawn primarily from studies on the Watchman device.

CONCLUSION

Although LAAO could be an alternative to anticoagulants for stroke prevention in patients with AF and high bleeding risk, the overall benefit from LAAO depends on the combination of stroke and bleeding risks in individual patients. These results suggest the need for a sufficiently low stroke risk for LAAO to be beneficial. The authors believe that these results could improve shared decision making when selecting patients for LAAO.

PRIMARY FUNDING SOURCE

None.

Artificial intelligence-electrocardiography to detect atrial fibrillation: trend of probability before and after the first episode

Aims

Artificial intelligence (AI) enabled electrocardiography (ECG) can detect latent atrial fibrillation (AF) in patients with sinus rhythm (SR). However, the change of AI-ECG probability before and after the first AF episode is not well characterized. We sought to characterize the temporal trend of AI-ECG AF probability around the first episode of AF.

Methods and results

We retrospectively studied adults who had at least one ECG in SR prior to an ECG that documented AF. An AI network calculated the AF probability from ECGs during SR (positive defined >8.7%, based on optimal sensitivity and specificity). The AI-ECG probability was reported prior to and after the first episode of AF and stratified by age and CHA₂DS₂-VASc score. Mixed effect models were used to assess the rate of change between time points. A total of 59 212 patients with 544 330 ECGs prior to AF and 413 486 ECGs after AF were included. The mean time between the first positive AI-ECG and first AF was 5.4 ± 5.7 years. The mean AI-ECG probability was 19.8% 2-5 years prior to AF, 23.6% 1-2 years prior to AF, 34.0% 0-3 months prior to AF, 40.9% 0-3 months after AF, 35.2% 1-2 years after AF, and 42.2% 2-5 years after AF (P < 0.001). The rate of increase prior to AF was higher for age >50 years CHA₂DS₂-VASc score ≥4.

Conclusion

The AI-ECG probability progressively increases with time prior to the first AF episode, transiently decreases 1-2 years following AF and continues to increase thereafter.

Cost-Effectiveness of Monitoring Patients Post-Stroke With Mobile ECG During the Hospital Stay

Background

The effectiveness of a nurse‐led in‐hospital monitoring protocol with mobile ECG (iECG) was investigated for detecting atrial fibrillation in patients post‐ischemic stroke or post‐transient ischemic attack. The study aimed to assess the cost‐effectiveness of using iECG during the initial hospital stay compared with standard 24‐hour Holter monitoring.

Methods and Results

A Markov microsimulation model was constructed to simulate the lifetime health outcomes and costs. The rate of atrial fibrillation detection in iECG and Holter monitoring during the in‐hospital phase and characteristics of modeled population (ie, age, sex, CHA2DS2‐VASc) were informed by patient‐level data. Costs related to recurrent stroke, stroke management, medications (new oral anticoagulants), and rehabilitation were included. The cost‐effectiveness analysis outcome was calculated as an incremental cost per quality‐adjusted life‐year gained. As results, monitoring patients with iECG post‐stroke during the index hospitalization was associated with marginally higher costs (A$31 196) and greater benefits (6.70 quality‐adjusted life‐years) compared with 24‐hour Holter surveillance (A$31 095 and 6.66 quality‐adjusted life‐years) over a 20‐year time horizon, with an incremental cost‐effectiveness ratio of $3013/ quality‐adjusted life‐years. Monitoring patients with iECG also contributed to lower recurrence of stroke and stroke‐related deaths (140 recurrent strokes and 20 deaths avoided per 10 000 patients). The probabilistic sensitivity analyses suggested iECG is highly likely to be a cost‐effective intervention (100% probability).

Conclusions

A nurse‐led iECG monitoring protocol during the acute hospital stay was found to improve the rate of atrial fibrillation detection and contributed to slightly increased costs and improved health outcomes. Using iECG to monitor patients post‐stroke during initial hospitalization is recommended to complement routine care.

Using machine learning to predict atrial fibrillation diagnosed after ischemic stroke

BACKGROUND

Selecting best candidates for prolonged poststroke cardiac monitoring in acute ischemic stroke (AIS) patients is still challenging. We aimed to develop a machine learning (ML) model to select AIS patients at high risk of poststroke atrial fibrillation (AF) for prolonged cardiac monitoring and then to compare ML model with traditional risk scores and classic statistical logistic regression (classic-LR) model.

METHODS

AIS patients from July 2012 to September 2020 across Nanjing First Hospital were collected. We performed the LASSO regression for selecting the critical features and built five ML models to assess the risk of poststroke AF. The SHAP and partial dependence plot (PDP) method were introduced to interpret the optimal model. We also compared ML model with CHADS₂ score, CHA₂DS₂-VASc score, AS5F score, HAVOC score, and classic-LR model.

RESULTS

A total of 3929 AIS patients were included. Among the five ML models, deep neural network (DNN) was the model with best performance. It also exhibited superior performance compared with CHADS₂ score, CHA₂DS₂-VASc score, AS5F score, HAVOC score and classic-LR model. The results of SHAP and PDP method revealed age, cardioembolic stroke, large-artery atherosclerosis stroke, and NIHSS score at admission were the top four important features and revealed the DNN model had good interpretability and reliability.

CONCLUSION

The DNN model achieved best performance and improved prediction performance compared with traditional risk scores and classic-LR model. The DNN model can be applied to identify AIS patients at high risk of poststroke AF as best candidates for prolonged poststroke cardiac monitoring.

Mobile Cardiac Outpatient Telemetry Patch vs Implantable Loop Recorder in Cryptogenic Stroke Patients in the US - Cost-Minimization Model

Purpose

The aim of this study was to compare costs and outcomes of mobile cardiac outpatient telemetry (MCOT) patch followed by implantable loop recorder (ILR) compared to ILR alone in cryptogenic stroke patients from the US health-care payors’ perspective.

Patients and Methods

A quantitative decision tree cost-minimization simulation model was developed. Eligible patients were 18 years of age or older and were diagnosed with having a cryptogenic stroke, without previously documented atrial fibrillation (AF). All patients were assigned first to one then to the alternative monitoring strategies. Following AF detection, patients were initiated on oral anticoagulants (OAC). The model assessed direct costs for one year attributed to MCOT patch followed by ILR or ILR alone using a monitoring duration of 30 days post-cryptogenic stroke.

Results

In the base case modeling, the MCOT patch arm detected 4.6 more patients with AFs compared to the ILR alone arm in a cohort of 1000 patients (209 vs 45 patients with detected AFs, respectively). Using MCOT patch followed by ILR in half of the patients initially undiagnosed with AF leads to significant cost savings of US$4,083,214 compared to ILR alone in a cohort of 1000 patients. Cost per patient with detected AF was significantly lower in the MCOT patch arm $29,598 vs $228,507 in the ILR only arm.

Conclusion

An initial strategy of 30-day electrocardiogram (ECG) monitoring with MCOT patch in diagnosis of AF in cryptogenic stroke patients realizes significant cost-savings compared to proceeding directly to ILR only. Almost 8 times lower costs were achieved with improved detection rates and reduction of secondary stroke risk due to new anticoagulant use in subjects with MCOT patch detected AF. These results strengthen emerging recommendations for prolonged ECG monitoring in secondary stroke prevention.

Embolic Stroke of Undetermined Source: Approaches in Risk Stratification for Cardioembolism

Ischemic stroke is a leading cause of morbidity and mortality worldwide. Embolic stroke of undetermined source has been recently proposed to categorize nonlacunar ischemic strokes without confirmed etiology after adequate investigation with a likely embolic stroke mechanism. A strategy of empirical anticoagulation for embolic stroke of undetermined source patients is attractive but may only be beneficial in a select subset of patients. Strategies which would help identify the subset of embolic stroke of undetermined source patients most likely to have cardioembolic origin of stroke, and hence benefit from anticoagulation, are needed. This article will review current evidence which may be useful in the development of a risk stratification approach based on arrhythmia monitoring, cardiac imaging, and clinical risk stratification. This approach may be beneficial in clinical practice in improving patient outcomes and reducing stroke recurrence in this population; however, further work is required with active trials underway.

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

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

Screening for Atrial Fibrillation in the Older Population: A Randomized Clinical Trial

Importance

Atrial fibrillation (AF) is a major cause of preventable strokes. Screening asymptomatic individuals for AF may increase anticoagulant use for stroke prevention.

Objective

To evaluate 2 home-based AF screening interventions.

Design, Setting, and Participants

This multicenter randomized clinical trial recruited individuals from primary care practices aged 75 years or older with hypertension and without known AF. From April 5, 2015, to March 26, 2019, 856 participants were enrolled from 48 practices.

Interventions

The control group received standard care (routine clinical follow-up plus a pulse check and heart auscultation at baseline and 6 months). The screening group received a 2-week continuous electrocardiographic (cECG) patch monitor to wear at baseline and at 3 months, in addition to standard care. The screening group also received automated home blood pressure (BP) machines with oscillometric AF screening capability to use twice-daily during the cECG monitoring periods.

Main Outcomes and Measures

With intention-to-screen analysis, the primary outcome was AF detected by cECG monitoring or clinically within 6 months. Secondary outcomes included anticoagulant use, device adherence, and AF detection by BP monitors.

Results

Of the 856 participants, 487 were women (56.9%); mean (SD) age was 80.0 (4.0) years. Median cECG wear time was 27.4 of 28 days (interquartile range [IQR], 18.4-28.0 days). In the primary analysis, AF was detected in 23 of 434 participants (5.3%) in the screening group vs 2 of 422 (0.5%) in the control group (relative risk, 11.2; 95% CI, 2.7-47.1; P = .001; absolute difference, 4.8%; 95% CI, 2.6%-7.0%; P < .001; number needed to screen, 21). Of those with cECG-detected AF, median total time spent in AF was 6.3 hours (IQR, 4.2-14.0 hours; range 1.3 hours-28 days), and median duration of the longest AF episode was 5.7 hours (IQR, 2.9-12.9 hours). Anticoagulation was initiated in 15 of 20 patients (75.0%) with cECG-detected AF. By 6 months, anticoagulant therapy had been prescribed for 18 of 434 participants (4.1%) in the screening group vs 4 of 422 (0.9%) in the control group (relative risk, 4.4; 95% CI, 1.5-12.8; P = .007; absolute difference, 3.2%; 95% CI, 1.1%-5.3%; P = .003). Twice-daily AF screening using the home BP monitor had a sensitivity of 35.0% (95% CI, 15.4%-59.2%), specificity of 81.0% (95% CI, 76.7%-84.8%), positive predictive value of 8.9% (95% CI, 4.9%-15.5%), and negative predictive value of 95.9% (95% CI, 94.5%-97.0%). Adverse skin reactions requiring premature discontinuation of cECG monitoring occurred in 5 of 434 participants (1.2%).

Conclusions and Relevance

In this randomized clinical trial, among older community-dwelling individuals with hypertension, AF screening with a wearable cECG monitor was well tolerated, increased AF detection 10-fold, and prompted initiation of anticoagulant therapy in most cases. Compared with continuous ECG, intermittent oscillometric screening with a BP monitor was an inferior strategy for detecting paroxysmal AF. Large trials with hard clinical outcomes are now needed to evaluate the potential benefits and harms of AF screening.

Trial Registration

ClinicalTrials.gov Identifier: NCT02392754.

Contemporary approach to diagnosis of ischemic stroke pathogenetic variants in patients with atherosclerosis and arterial hypertension

The angio- and neurovisualization methods vigorously developing in recent decades determine the relevance of improvement of etiopathogenetic ischemic stroke classification used for the treatment tactics selection and for secondary prevention of the disorder. The study was aimed to clarify the capabilities of clinical diagnosis for pathogenetic variants of ischemic stroke. For that, in 125 postmortem cases, the macro and microscopic examination of brain and cardiovascular system was carried out in order to verify the stroke pathogenesis established as a result of the previous patients’ examination. The study demonstrates the great potential of the major pathogenetic stroke subtypes (large-artery atherosclerosis, cardioembolism, small-artery occlusion) diagnosis using the complex of contemporary clinical and instrumental methods and the main morphological criteria of these subtypes in accordance with the TOAST classification. Moreover, the clinical and pathomorphological assessment allowed us to differentiate stroke resulting from various alterations of single cerebral artery, the atherothrombotic occlusion (44% of cases for the subtype), arterio-arterial embolism (13%) and critical stenosis (10%), as well as stroke resulting from cerebrovascular insufficiency (33%), within the “large-artery atherosclerosis” subtype. Thus, the high informativity of the existing examination methods allows for a more differentiated understanding of the cause of ischemic stroke, which is fully in line with modern personalized medicine.

Economic evaluation of extended electrocardiogram monitoring for atrial fibrillation in patients with cryptogenic stroke

BACKGROUND

Timely identification of occult atrial fibrillation following cryptogenic stroke facilitates consideration of oral anticoagulation therapy. Extended electrocardiography monitoring beyond 24 to 48 h Holter monitoring improves atrial fibrillation detection rates, yet uncertainty remains due to upfront costs and the projected long-term benefit. We sought to determine the cost-effectiveness of three electrocardiography monitoring strategies in detecting atrial fibrillation after cryptogenic stroke.

METHODS

A decision-analytic Markov model was used to project the costs and outcomes of three different electrocardiography monitoring strategies (i.e. 30-day electrocardiography monitoring, three-year implantable loop recorder monitoring, and conventional Holter monitoring) in acute stroke survivors without previously documented atrial fibrillation.

RESULTS

The lifetime discounted costs and quality-adjusted life years were $206,385 and 7.77 quality-adjusted life years for conventional monitoring, $207,080 and 7.79 quality-adjusted life years for 30-day extended electrocardiography monitoring, and $210,728 and 7.88 quality-adjusted life years for the implantable loop recorder strategy. Additional quality-adjusted life years could be attained at a more favorable incremental cost per quality-adjusted life year with the implantable loop recorder strategy, compared with the 30-day electrocardiography monitoring strategy, thereby eliminating the 30-day strategy by extended dominance. The implantable loop recorder strategy was associated with an incremental cost per quality-adjusted life year gained of $40,796 compared with conventional monitoring. One-way sensitivity analyses indicated that the model was most sensitive to the rate of recurrent ischemic stroke.

CONCLUSIONS

An implantable loop recorder strategy for detection of occult atrial fibrillation in patients with cryptogenic stroke is more economically attractive than 30-day electrocardiography monitoring compared to conventional monitoring and is associated with a cost per quality-adjusted life year gained in the range of other publicly funded therapies. The value proposition is improved when considering patients at the highest risk of recurrent ischemic stroke. However, the implantable loop recorder strategy is associated with increased health care costs, and the opportunity cost of wide scale implementation must be considered.

The 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Comprehensive Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) atrial fibrillation (AF) guidelines program was developed to aid clinicians in the management of these complex patients, as well as to provide direction to policy makers and health care systems regarding related issues. The most recent comprehensive CCS AF guidelines update was published in 2010. Since then, periodic updates were published dealing with rapidly changing areas. However, since 2010 a large number of developments had accumulated in a wide range of areas, motivating the committee to complete a thorough guideline review. The 2020 iteration of the CCS AF guidelines represents a comprehensive renewal that integrates, updates, and replaces the past decade of guidelines, recommendations, and practical tips. It is intended to be used by practicing clinicians across all disciplines who care for patients with AF. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate recommendation strength and the quality of evidence. Areas of focus include: AF classification and definitions, epidemiology, pathophysiology, clinical evaluation, screening and opportunistic AF detection, detection and management of modifiable risk factors, integrated approach to AF management, stroke prevention, arrhythmia management, sex differences, and AF in special populations. Extensive use is made of tables and figures to synthesize important material and present key concepts. This document should be an important aid for knowledge translation and a tool to help improve clinical management of this important and challenging arrhythmia.

Cost-Effectiveness of Extended Electrocardiogram Monitoring for Atrial Fibrillation After Stroke

Background and Purpose:

Management of cryptogenic stroke involves the identification of modifiable risk factors, such as atrial fibrillation (AF). Extended rhythm monitoring increases AF detection rates but at an increased device cost compared with conventional Holter monitoring. The objective of the study was to identify and synthesize the existing literature on the cost-effectiveness of prolonged rhythm monitoring devices for AF detection in cryptogenic stroke.

Methods:

We conducted a systematic review of available economic evaluations of prolonged ECG monitoring for AF detection following cryptogenic stroke compared with standard care.

Results:

Of the 530 unique citations, 8 studies assessed the cost-utility of prolonged ECG monitoring compared with standard care following cryptogenic stroke. The prolonged ECG monitoring strategies included 7-day ambulatory monitoring, 30-day external loop recorders or intermittent ECG monitoring, and implantable loop recorders. The majority of cost-utility analyses reported incremental cost-effectiveness ratios below $50 000 per QALY gained; and two studies reported a cost-savings.

Conclusions:

There is limited economic literature on the cost-effectiveness of extended ECG monitoring devices for detection of atrial fibrillation in cryptogenic stroke. In patients with cryptogenic stroke, extended ECG monitoring for AF detection may be economically attractive when traditional willingness-to-pay thresholds are adopted. However, there was substantial variation in the reported ICERs. The direct comparison of cost-effectiveness across technologies is limited by heterogeneity in modeling assumptions.

Cardiac Imaging After Ischemic Stroke or Transient Ischemic Attack

PURPOSE OF REVIEW

Cardiac imaging after ischemic stroke or transient ischemic attack (TIA) is used to identify potential sources of cardioembolism, to classify stroke etiology leading to changes in secondary stroke prevention, and to detect frequent comorbidities. This article summarizes the latest research on this topic and provides an approach to clinical practice to use cardiac imaging after stroke.

RECENT FINDINGS

Echocardiography remains the primary imaging method for cardiac work-up after stroke. Recent echocardiography studies further demonstrated promising results regarding the prediction of non-permanent atrial fibrillation after ischemic stroke. Cardiac magnetic resonance imaging and computed tomography have been tested for their diagnostic value, in particular in patients with cryptogenic stroke, and can be considered as second line methods, providing complementary information in selected stroke patients. Cardiac imaging after ischemic stroke or TIA reveals a potential causal condition in a subset of patients. Whether systematic application of cardiac imaging improves outcome after stroke remains to be established.

Implantable loop recorder monitoring in patients with cryptogenic stroke - Detection and treatment of different clinically relevant arrhythmias

AIMS

Implantable loop recorders (ILR) are recommended to detect atrial fibrillation (AF) in cases of cryptogenic stroke. However, real life data besides controlled trials are rare. Aim of the study was the detection of atrial fibrillation with a special focus on other arrhythmias according to criteria defined in earlier clinical trials.

METHODS

We performed a retrospective analysis of 64 patients with cryptogenic stroke who underwent ILR implantation between 4/2014 and 1/2018. The primary endpoint was the detection of atrial fibrillation, significant bradycardia (<40 bpm) or tachycardia (>150 bpm). ILR interrogation was performed after implantation and 6, 12 and 24 months thereafter.

RESULTS

Mean patients age was 65.4 ± 12 years, 50% were male. Mean follow-up duration was 419.2 ± 309 days. One death occurred during follow-up. 23 patients (35.9%) experienced a symptomatic clinical neurological or cardiac event during follow-up. Overall rate of detected arrhythmias was 35% (23/64). The most frequent arrhythmia was atrial fibrillation which was observed in 16 patients (25%). 6 of 16 patients presenting with atrial fibrillation had no clinical symptoms. Bradycardias requiring subsequent pacemaker implantations were detected in 9.4%. A ventricular tachycardia was observed in one patient (1.6%).

CONCLUSION

In this group of patients with cryptogenic stroke the rate of arrhythmic events was high. Besides a high rate of atrial fibrillation (25%), an unexpectedly high rate of bradyarrhythmias (9.4%) occurred in our patient collective. Since many of those episodes were clinically asymptomatic, the ILR helps to detect and treat those clinically silent arrhythmias.

El Kassabi H, Ismail H, Nujum Navaz A. ECG Monitoring Systems: Review, Architecture, Processes, and Key Challenges

Health monitoring and its related technologies is an attractive research area. The electrocardiogram (ECG) has always been a popular measurement scheme to assess and diagnose cardiovascular diseases (CVDs). The number of ECG monitoring systems in the literature is expanding exponentially. Hence, it is very hard for researchers and healthcare experts to choose, compare, and evaluate systems that serve their needs and fulfill the monitoring requirements. This accentuates the need for a verified reference guiding the design, classification, and analysis of ECG monitoring systems, serving both researchers and professionals in the field. In this paper, we propose a comprehensive, expert-verified taxonomy of ECG monitoring systems and conduct an extensive, systematic review of the literature. This provides evidence-based support for critically understanding ECG monitoring systems' components, contexts, features, and challenges. Hence, a generic architectural model for ECG monitoring systems is proposed, an extensive analysis of ECG monitoring systems' value chain is conducted, and a thorough review of the relevant literature, classified against the experts' taxonomy, is presented, highlighting challenges and current trends. Finally, we identify key challenges and emphasize the importance of smart monitoring systems that leverage new technologies, including deep learning, artificial intelligence (AI), Big Data and Internet of Things (IoT), to provide efficient, cost-aware, and fully connected monitoring systems.

Thirty-Year Risk of Cardiovascular Disease Events in Adolescents with Severe Obesity

OBJECTIVE

Quantifying risk for cardiovascular disease (CVD) events among adolescents is difficult owing to the long latent period between risk factor development and disease outcomes. This study examined the 30-year CVD event risk among adolescents with severe obesity treated with and without metabolic and bariatric surgery (MBS), compared with youths with moderate obesity, overweight, or normal weight.

METHODS

Cross-sectional and longitudinal comparisons of five frequency-matched (age and diabetes status) groups were performed: normal weight (n = 247), overweight (n = 54), obesity (n = 131), severe obesity without MBS (n = 302), and severe obesity undergoing MBS (n = 215). A 30-year CVD event score developed by the Framingham Heart Study was the primary outcome. Data are mean (SD) with differences between time points for MBS examined using linear mixed models.

RESULTS

Preoperatively, the likelihood of CVD events was higher among adolescents undergoing MBS (7.9% [6.7%]) compared with adolescents with severe obesity not referred for MBS (5.5% [4.0%]), obesity (3.9% [3.0%]), overweight (3.1% [2.4%]), and normal weight (1.8% [0.8%]; all P < 0.001). At 1 year after MBS, event risk was significantly reduced (7.9% [6.7%] to 4.0% [3.4%], P < 0.0001) and was sustained for up to 5 years after MBS (P < 0.0001, all years vs. baseline).

CONCLUSIONS

Adolescents with severe obesity are at elevated risk for future CVD events. Following MBS, the predicted risk of CVD events was substantially and sustainably reduced.

Searching for Atrial Fibrillation Poststroke: A White Paper of the AF-SCREEN International Collaboration

Cardiac thromboembolism attributed to atrial fibrillation (AF) is responsible for up to one-third of ischemic strokes. Stroke may be the first manifestation of previously undetected AF. Given the efficacy of oral anticoagulants in preventing AF-related ischemic strokes, strategies of searching for AF after a stroke using ECG monitoring followed by oral anticoagulation (OAC) treatment have been proposed to prevent recurrent cardioembolic strokes. This white paper by experts from the AF-SCREEN International Collaboration summarizes existing evidence and knowledge gaps on searching for AF after a stroke by using ECG monitoring. New AF can be detected by routine plus intensive ECG monitoring in approximately one-quarter of patients with ischemic stroke. It may be causal, a bystander, or neurogenically induced by the stroke. AF after a stroke is a risk factor for thromboembolism and a strong marker for atrial myopathy. After acute ischemic stroke, patients should undergo 72 hours of electrocardiographic monitoring to detect AF. The diagnosis requires an ECG of sufficient quality for confirmation by a health professional with ECG rhythm expertise. AF detection rate is a function of monitoring duration and quality of analysis, AF episode definition, interval from stroke to monitoring commencement, and patient characteristics including old age, certain ECG alterations, and stroke type. Markers of atrial myopathy (eg, imaging, atrial ectopy, natriuretic peptides) may increase AF yield from monitoring and could be used to guide patient selection for more intensive/prolonged poststroke ECG monitoring. Atrial myopathy without detected AF is not currently sufficient to initiate OAC. The concept of embolic stroke of unknown source is not proven to identify patients who have had a stroke benefitting from empiric OAC treatment. However, some embolic stroke of unknown source subgroups (eg, advanced age, atrial enlargement) might benefit more from non-vitamin K-dependent OAC therapy than aspirin. Fulfilling embolic stroke of unknown source criteria is an indication neither for empiric non-vitamin K-dependent OAC treatment nor for withholding prolonged ECG monitoring for AF. Clinically diagnosed AF after a stroke or a transient ischemic attack is associated with significantly increased risk of recurrent stroke or systemic embolism, in particular, with additional stroke risk factors, and requires OAC rather than antiplatelet therapy. The minimum subclinical AF duration required on ECG monitoring poststroke/transient ischemic attack to recommend OAC therapy is debated.

Early prolonged ambulatory cardiac monitoring in stroke (EPACS): an open-label randomised controlled trial

Background

Cardioembolism in paroxysmal atrial fibrillation (PAF) is a preventable cause of transient ischaemic attack (TIA) or ischaemic stroke; however, due to its transient nature, a short-duration Holter monitor may miss a significant proportion of events.

Methods

We conducted an open-label randomised controlled trial of cardiac monitoring after a TIA or ischaemic stroke comparing a 14-day ECG monitoring patch (Zio^® Patch, iRhythm Technologies) with short-duration Holter monitoring for the detection of PAF. The primary outcome was the detection of one or more episodes of ECG-documented PAF lasting at least 30 s within 90 days in each of the study arms. A budget impact analysis from the healthcare perspective was performed.

Results

From February 2016 through February 2017, 43 (76.8%) of the 56 patients assigned to the patch-based monitoring group and 47 (78.3%) of the 60 patients assigned to short-duration Holter monitoring group had successful monitor placement with 90 days of follow-up. Of the 26 protocol failures between the two groups, 23 (88.5%) were due to patient refusal for outpatient short-duration ECG monitor placement, whilst only 1 (3.8%) was due unsuccessful ZioPatch placement. The rate of detection of PAF at 90 days was 16.3% in the patch-based monitoring group (seven patients) compared to 2.1% in the short-duration Holter monitoring group (1 patient), with an odds ratio of 8.9 (95% CI 1.1–76.0; P = 0.026). An economic model demonstrated that implementation of the Zio Patch service would result in 10.8 more strokes avoided per year compared to current practice with Holter monitoring with an associated yearly saving in direct medical costs of £113,630, increasing to £162,491 over 5 years.

Conclusions

Early, prolonged, patch-based monitoring after an index stroke or TIA is superior to short-duration Holter monitoring in the detection of PAF and likely cost-effective for preventing recurrent strokes.

Trial registrationhttp://www.isrctn.com. Unique identifier: ISRCTN 50253271. Registered 21 January 2016

Electronic supplementary material

The online version of this article (10.1186/s40001-019-0383-8) contains supplementary material, which is available to authorized users.

Health Economic Evaluations of Digital Health Interventions for Secondary Prevention in Stroke Patients: A Systematic Review

BACKGROUND

In the first 5 years after their stroke, about a quarter of patients will suffer from a recurrent stroke. Digital health interventions facilitating interactions between a caregiver and a patient from a distance are a promising approach to improve patient adherence to lifestyle changes proposed by secondary prevention guidelines. Many of these interventions are not implemented in daily practice, even though efficacy has been shown. One of the reasons can be the lack of clear economic incentives for implementation. We propose to map all health economic evidence regarding digital health interventions for secondary stroke prevention.

SUMMARY

We performed a systematic search according to PRISMA-P guidelines and searched on PubMed, Web of Science, Cochrane, and National Institute for Health Research Economic Evaluation Database. Only digital health interventions for secondary prevention in stroke patients were included and all study designs and health economic outcomes were accepted. We combined the terms "Stroke OR Cardiovascular," "Secondary prevention," "Digital health interventions," and "Cost" in one search string using the AND operator. The search performed on April 20, 2017 yielded 163 records of which 26 duplicates were removed. After abstract screening, 20 articles were retained for full-text analysis, of which none reported any health economic evidence that could be included for analysis or discussion. Key Messages: There is a lack of evidence on health economic outcomes on digital health interventions for secondary stroke prevention. Future research in this area should take health economics into consideration when designing a trial and there is a clear need for health economic evidence and models.

Expert opinion paper on atrial fibrillation detection after ischemic stroke

This expert opinion paper on atrial fibrillation detection after ischemic stroke includes a statement of the "Heart and Brain" consortium of the German Cardiac Society and the German Stroke Society. This paper was endorsed by the Stroke Unit-Commission of the German Stroke Society and the German Atrial Fibrillation NETwork. In patients with ischemic stroke, detection of atrial fibrillation should usually lead to a change in secondary stroke prevention, since oral anticoagulation is superior to antiplatelet drugs. The detection of previously undiagnosed atrial fibrillation can be improved in patients with ischemic stroke to optimize stroke prevention. This paper summarizes the present knowledge on atrial fibrillation detection after ischemic stroke. We propose an interdisciplinary standard for a "structured analysis of ECG monitoring" on the stroke unit as well as a staged diagnostic scheme for the detection of atrial fibrillation. Since the optimal duration and mode of ECG monitoring has not yet been finally established, this paper is intended to give advice to physicians who are involved in stroke care. In line with the nature of an expert opinion paper, labeling of classes of recommendations is not provided, since many statements are based on the expert opinion, reported case series and clinical experience. Therefore, this paper is not intended as a guideline.

Atrial fibrillation is associated with anterior predominant white matter lesions in patients presenting with embolic stroke

OBJECTIVE

High white matter hyperintensity (WMH) burden is commonly found on brain MRI among patients with atrial fibrillation (AF). However, whether the link between AF and WMH extends beyond a common vascular risk factor profile is uncertain. We sought to determine whether AF relates to a distinct WMH lesion pattern which may suggest specific underlying pathophysiological relationships.

METHODS

We retrospectively analysed a cohort of consecutive patients presenting with embolic stroke at an academic hospital and tertiary referral centre between March 2010 and March 2014. In total, 234 patients (53% female, 74% anterior circulation infarction) fulfilled the inclusion criteria and were included in the analyses. WMH lesion distribution was classified according to previously defined categories. Multivariable logistic regression analysis was performed to determine variables associated with AF within 90 days of index hospital discharge.

RESULTS

Among included patients, 114 had AF (49%). After adjustment for the CHA₂DS₂-VASc score (congestive heart failure, hypertension, age ≥75 years (doubled), diabetes mellitus, prior stroke/TIA (doubled), vascular disease, age 65-74 years, sex category (female)) score, WMH lesion burden as assessed on the Fazekas scale, embolic stroke pattern, infarct distribution and pertinent interaction terms, AF was significantly associated with presence of anterior subcortical WMH patches (OR 3.647, 95% CI 1.681 to 7.911, p=0.001).

CONCLUSIONS

AF is associated with specific WMH lesion pattern among patients with embolic stroke aetiology. This suggests that the link between AF and brain injury extends beyond thromboembolic complications to include a cardiovasculopathy that affects the brain and can be detected and characterised by WMH.

Screening for Atrial Fibrillation

Approximately 10% of ischemic strokes are associated with atrial fibrillation (AF) first diagnosed at the time of stroke. Detecting asymptomatic AF would provide an opportunity to prevent these strokes by instituting appropriate anticoagulation. The AF-SCREEN international collaboration was formed in September 2015 to promote discussion and research about AF screening as a strategy to reduce stroke and death and to provide advocacy for implementation of country-specific AF screening programs. During 2016, 60 expert members of AF-SCREEN, including physicians, nurses, allied health professionals, health economists, and patient advocates, were invited to prepare sections of a draft document. In August 2016, 51 members met in Rome to discuss the draft document and consider the key points arising from it using a Delphi process. These key points emphasize that screen-detected AF found at a single timepoint or by intermittent ECG recordings over 2 weeks is not a benign condition and, with additional stroke factors, carries sufficient risk of stroke to justify consideration of anticoagulation. With regard to the methods of mass screening, handheld ECG devices have the advantage of providing a verifiable ECG trace that guidelines require for AF diagnosis and would therefore be preferred as screening tools. Certain patient groups, such as those with recent embolic stroke of uncertain source (ESUS), require more intensive monitoring for AF. Settings for screening include various venues in both the community and the clinic, but they must be linked to a pathway for appropriate diagnosis and management for screening to be effective. It is recognized that health resources vary widely between countries and health systems, so the setting for AF screening should be both country- and health system-specific. Based on current knowledge, this white paper provides a strong case for AF screening now while recognizing that large randomized outcomes studies would be helpful to strengthen the evidence base.