Temporal association between atrial fibrillation and ischemic stroke: Systematic review and meta-analysis

BACKGROUND

Paroxysmal atrial fibrillation (PAF) is strongly associated with ischemic stroke. Continuous cardiac implantable electronic devices (CIEDs) can assess PAF episodes over prolonged periods. Studies that attempted to find a temporal association between PAF and ischemic stroke were inconclusive. Thus, we performed a systematic review and meta-analysis to assess this relationship.

AIMS

This study aimed to assess the temporal association between AF episodes and stroke within 30 days of the arrhythmic episode. The secondary outcome is a temporal association within a 90-day period.

SUMMARY OF REVIEW

A total of 2804 studies that discussed the temporal relationship between PAF and ischemic stroke were screened, and 7 studies were included in the meta-analysis. Among the 4041 patients included in these studies, there were 138 patients with device detected PAF episodes and stroke. Four studies used a 30-day window for temporality and the pooled odds ratio (OR) showed a significant association (OR 4.11 (95% CI 1.03-16.40)). The three studies reporting on AF and stroke within a 90-day window did not find a significant temporal relationship (OR 0.43 (95% CI 0.13-1.41)). Finally, the pooled result of those seven studies did not show a significant association (OR 1.51 (95% CI 0.44-5.17)).

CONCLUSION

This meta-analysis supports a temporal relationship between PAF and ischemic stroke within a 30-day window. Establishing this relationship is important for individualized risk prediction and targeted anticoagulation treatment.

DATA ACCESS STATEMENT

The data will be made available upon reasonable request.

Heart Failure Management through Telehealth: Expanding Care and Connecting Hearts

Heart failure (HF) is a leading cause of morbidity worldwide, imposing a significant burden on deaths, hospitalizations, and health costs. Anticipating patients' deterioration is a cornerstone of HF treatment: preventing congestion and end organ damage while titrating HF therapies is the aim of the majority of clinical trials. Anyway, real-life medicine struggles with resource optimization, often reducing the chances of providing a patient-tailored follow-up. Telehealth holds the potential to drive substantial qualitative improvement in clinical practice through the development of patient-centered care, facilitating resource optimization, leading to decreased outpatient visits, hospitalizations, and lengths of hospital stays. Different technologies are rising to offer the best possible care to many subsets of patients, facing any stage of HF, and challenging extreme scenarios such as heart transplantation and ventricular assist devices. This article aims to thoroughly examine the potential advantages and obstacles presented by both existing and emerging telehealth technologies, including artificial intelligence.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

Association of Device-Detected Atrial High-Rate Episodes With Long-term Cardiovascular and All-Cause Mortality: A Cohort Study

BACKGROUND

Device-detected atrial high-rate episodes (AHREs) were associated with an increased thromboembolic risk. Although limited data regarding the long-term prognosis of patients with AHRE were controversial, this study aimed to identify the association of device-detected AHRE with mortality.

METHODS

This observational study included patients with implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) placement and no history of atrial fibrillation (AF), atrial flutter (AFL), or atrial tachycardia (AT). During follow-up, patients with at least 1 day of AHRE duration ≥ 15 minutes were identified. The primary endpoint was cardiovascular mortality, and the secondary endpoint was all-cause mortality.

RESULTS

During a mean follow-up period of 4.2 years, AHREs were detected in 124 of 343 (36.2%) patients. Of these, 44 deaths (35.5%) occurred in 124 patients with AHREs, which was significantly higher than those without AHREs (43 of 219; 19.6%; P = 0.001). The multivariate analysis revealed that patients with AHRE had a significantly higher risk of cardiovascular (hazard ratio [HR], 2.40; 95% confidence interval [CI], 1.23-4.67; P = 0.010), and all-cause mortality (HR, 2.31; 95% CI, 1.49-3.59; P < 0.001). Further analysis indicated that this association remained significant in patients with higher burden (≥ 6 hours) but not in patients with lower burden (≥ 15 minutes to 6 hours). Notably, even after excluding the patients diagnosed with clinical AF during follow-up, the remaining patients with AHREs still exhibited a higher risk of cardiovascular and all-cause mortality compared with patients without AHREs.

CONCLUSIONS

AHREs were prevalent in ICD or CRT-D recipients with no history of clinical AF, AFL, or AT and were associated with more than twice the risk of cardiovascular and all-cause mortality.

CLINICAL TRIAL REGISTRATION

No. ChiCTR-ONRC-13003695.

Pathophysiology and clinical relevance of atrial myopathy

Atrial myopathy is a condition that consists of electrical, structural, contractile, and autonomic remodeling of the atria and is the substrate for development of atrial fibrillation, the most common arrhythmia. Pathophysiologic mechanisms driving atrial myopathy are inflammation, oxidative stress, atrial stretch, and neurohormonal signals, e.g., angiotensin-II and aldosterone. These mechanisms initiate the structural and functional remodeling of the atrial myocardium. Novel therapeutic strategies are being developed that target the pathophysiologic mechanisms of atrial myopathy. In this review, we will discuss the pathophysiology of atrial myopathy, as well as diagnostic and therapeutic strategies.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Direct Oral Anticoagulants for Stroke Prevention in Patients With Device-Detected Atrial Fibrillation: A Study-Level Meta-Analysis of the NOAH-AFNET 6 and ARTESiA Trials

BACKGROUND

Device-detected atrial fibrillation (also known as subclinical atrial fibrillation or atrial high-rate episodes) is a common finding in patients with an implanted cardiac rhythm device and is associated with an increased risk of ischemic stroke. Whether oral anticoagulation is effective and safe in this patient population is unclear.

METHODS

We performed a systematic review of MEDLINE and Embase for randomized trials comparing oral anticoagulation with antiplatelet or no antithrombotic therapy in adults with device-detected atrial fibrillation recorded by a pacemaker, implantable cardioverter defibrillator, cardiac resynchronization therapy device, or implanted cardiac monitor. We used random-effects models for meta-analysis and rated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework (GRADE). The review was preregistered (PROSPERO CRD42023463212).

RESULTS

From 785 citations, we identified 2 randomized trials with relevant clinical outcome data: NOAH-AFNET 6 (Non-Vitamin K Antagonist Oral Anticoagulants in Patients With Atrial High Rate Episodes; 2536 participants) evaluated edoxaban, and ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation; 4012 participants) evaluated apixaban. Meta-analysis demonstrated that oral anticoagulation with these agents reduced ischemic stroke (relative risk [RR], 0.68 [95% CI, 0.50-0.92]; high-quality evidence). The results from the 2 trials were consistent (I2 statistic for heterogeneity=0%). Oral anticoagulation also reduced a composite of cardiovascular death, all-cause stroke, peripheral arterial embolism, myocardial infarction, or pulmonary embolism (RR, 0.85 [95% CI, 0.73-0.99]; I2=0%; moderate-quality evidence). There was no reduction in cardiovascular death (RR, 0.95 [95% CI, 0.76-1.17]; I2=0%; moderate-quality evidence) or all-cause mortality (RR, 1.08 [95% CI, 0.96-1.21]; I2=0%; moderate-quality evidence). Oral anticoagulation increased major bleeding (RR, 1.62 [95% CI, 1.05-2.50]; I²=61%; high-quality evidence).

CONCLUSIONS

The results of the NOAH-AFNET 6 and ARTESiA trials are consistent with each other. Meta-analysis of these 2 large randomized trials provides high-quality evidence that oral anticoagulation with edoxaban or apixaban reduces the risk of stroke in patients with device-detected atrial fibrillation and increases the risk of major bleeding.

Atrial myopathy

This paper delves into the progressive concept of atrial myopathy, shedding light on its development and its impact on atrial characteristics. It extensively explores the intricate connections between atrial myopathy, atrial fibrillation (AF), and strokes. Researchers have sought additional contributors to AF-related strokes due to the absence of a clear timing correlation between paroxysmal AF episodes and strokes in patients with cardiac implantable electronic devices. Through various animal models and human investigations, a close interrelation among aging, inflammation, oxidative stress, and stretching mechanisms has been identified. These mechanisms contribute to fibrosis, alterations in electrical properties, autonomic remodeling, and a heightened pro-thrombotic state. These interconnected factors establish a detrimental cycle, exacerbating atrial myopathy and elevating the risk of sustained AF and strokes. By emphasizing the significance of atrial myopathy and the risk of strokes that are distinct from AF, the paper also discusses methods for identifying patients with atrial myopathy. Moreover, it proposes an approach to incorporate the concept of atrial myopathy into clinical practice to guide anticoagulation decisions in individuals with AF.

The relationship between atrial cardiopathy biomarkers and prognosis of patients with acute ischemic stroke after endovascular treatment

Thromboembolism is a possible consequence of underlying atrial cardiopathy, which can occur even before the onset of atrial fibrillation. Our objective was to examine the association between biomarkers of atrial cardiopathy and outcomes of acute ischemic stroke (AIS) following endovascular treatment (EVT). We conducted a retrospective study that collected data from patients with AIS who underwent EVT and compared the outcomes between those with and without atrial cardiopathy. Neurological function was assessed using the modified Rankin Scale (mRS), with an mRS score >2 indicating poor function at day 90. Additionally, we evaluated secondary consequences, including symptomatic intracerebral hemorrhage (sICH), early neurological deterioration (END), and malignant cerebral edema (MCE). Our study included 87 patients (77.6 ​% male; mean age 60.93 ​± ​12.47 years). Among these patients, 29 (33.3 ​%) had atrial cardiopathy, while the remaining 58 (66.7 ​%) did not. In the atrial cardiopathy group, 12 patients (41.4 ​%) had poor functional outcomes (mRS>2), compared to 19 (32.8 ​%) in the non-atrial cardiopathy group. We observed sICH in 22 (25.3 ​%) patients, END in 14 (16.1 ​%) patients, MCE in 11 (12.6 ​%) patients, and two (2.3 ​%) patients who died in the hospital. We found that patients with PTFV1>5000 ​μV/ms (OR: 8.39, 95 ​% CI: 1.43-105.95, P ​= ​0.02) and NT-proBNP>250 ​pg/mL (OR: 5.09, 95 ​% CI: 1.20-27.63, P ​= ​0.03) had significantly higher risk of END. After adjusting for covariates in the Firth logistic regression, we further found that atrial cardiopathy was significantly associated with END, as revealed by both univariate (OR: 6.31, 95 ​% CI: 1.42-59.87, P ​= ​0.01) and multivariable firth regression models (Modle 1, OR: 7.10, 95 ​% CI: 1.57-67.38, P ​< ​0.01; Modle 2, OR: 7.82, 95 ​% CI: 1.69, 76.36, P ​< ​0.01; Modle 3, OR: 8.59, 95 ​% CI: 1.72-91.70, P ​< ​0.01). Moreover, we observed that atrial cardiopathy was associated with an increased risk of END in AIS patients with large artery atherosclerosis (LAA) receiving EVT. Therefore, clinicians should consider atrial cardiopathy as a possible underlying cause of AIS in their patients. Further investigation is warranted to elucidate the relationship between atrial cardiopathy and AIS's occurrence, progression, and prognosis.

Novel stroke prevention strategies following catheter ablation for atrial fibrillation

Stroke prevention following successful catheter ablation of atrial fibrillation remains a controversial topic. Oral anticoagulation is associated with a significant reduction in stroke risk in the general atrial fibrillation population but may be associated with an increased risk of major bleeding, and the benefit: risk ratio must be considered. Improvement in successful catheter ablation and widespread use of cardiac monitoring devices may allow for novel anticoagulation strategies in a subset of patients with atrial fibrillation, which may optimize stroke prevention while minimizing bleeding risk. In this review, we discuss stroke risk in atrial fibrillation and the effects of successful catheter ablation on thromboembolic risk. We also explore novel strategies for stroke prevention following successful catheter ablation.

Robust Artificial Intelligence Tool for Atrial Fibrillation Diagnosis: Novel Development Approach Incorporating Both Atrial Electrograms and Surface ECG and Evaluation by Head-to-Head Comparison With Hospital-Based Physician ECG Readers

BACKGROUND

Atrial fibrillation (AF) increases risk of embolic stroke, and in postoperative patients, increases cost of care. Consequently, ECG screening for AF in high-risk patients is important but labor-intensive. Artificial intelligence (AI) may reduce AF detection workload, but AI development presents challenges.

METHODS AND RESULTS

We used a novel approach to AI development for AF detection using both surface ECG recordings and atrial epicardial electrograms obtained in postoperative cardiac patients. Atrial electrograms were used only to facilitate establishing true AF for AI development; this permitted the establishment of an AI-based tool for subsequent AF detection using ECG records alone. A total of 5 million 30-second epochs from 329 patients were annotated as AF or non-AF by expert ECG readers for AI training and validation, while 5 million 30-second epochs from 330 different patients were used for AI testing. AI performance was assessed at the epoch level as well as AF burden at the patient level. AI achieved an area under the receiver operating characteristic curve of 0.932 on validation and 0.953 on testing. At the epoch level, testing results showed means of AF detection sensitivity, specificity, negative predictive value, positive predictive value, and F1 (harmonic mean of positive predictive value and sensitivity) as 0.970, 0.814, 0.976, 0.776, and 0.862, respectively, while the intraclass correlation coefficient for AF burden detection was 0.952. At the patient level, AF burden sensitivity and positive predictivity were 96.2% and 94.5%, respectively.

CONCLUSIONS

Use of both atrial electrograms and surface ECG permitted development of a robust AI-based approach to postoperative AF recognition and AF burden assessment. This novel tool may enhance detection and management of AF, particularly in patients following operative cardiac surgery.

Clinical Characteristics and Rhythm Outcomes in Patients With Atrial Myopathy After Successful Catheter Ablation of Atrial Fibrillation

BACKGROUND

Although successful atrial fibrillation (AF) ablation can maintain sinus rhythm and reduce the left atrial (LA) dimension, blunted LA reverse remodeling can be observed in patients with atrial myopathy. We explored the potential mechanisms and long-term outcomes in patients with blunted LA reverse remodeling after successful AF catheter ablation.

METHODS AND RESULTS

We included 1685 patients who underwent baseline and 1-year follow-up echocardiograms, had a baseline LA dimension ≥40 mm, and did not have a recurrence of AF within a year. The patients were divided into tertile groups according to the delta value of the change in LA dimension on the preprocedure and 1-year postprocedure echocardiography. After propensity score matching for age, sex, AF type, and LA dimension, 1272 patients were finally included in the analyses (424 in each group; the least/blunted, moderate, and the most reverse remodeling group). The patients in the T1 group (blunted LA reverse remodeling) were independently associated with higher left ventricular mass index (odds ratio [OR], 1.014 [95% CI, 1.005-1.022], P=0.001), change in ΔH2FPEF score (heavy, hypertensive, atrial fibrillation, pulmonary hypertension, elder, filling pressure) score (OR, 1.445 [95% CI, 1.121-1.861], P=0.004), ventricular epicardial adipose tissue volume (OR, 1.010 [95% CI, 1.003-1.017], P=0.003), thinner LA wall thickness (OR, 0.461 [95% CI, 0.271-0.785], P=0.004), lower LA voltage (OR, 0.670 [95% CI, 0.499-0.899], P=0.008), and showed higher long-term AF recurrence (log-rank P<0.001) than other groups.

CONCLUSIONS

Blunted LA reverse remodeling after AF catheter ablation, which is suggestive of atrial myopathy, was independently associated with a larger ventricular epicardial adipose tissue volume and worsening of H2FPEF score. Blunted LA reverse remodeling after AF catheter ablation was also an independent predictor for higher recurrences of AF post-1-year AF catheter ablation.

Is there a temporal relationship between atrial fibrillation and stroke? A review

Importance

Atrial fibrillation (AF) is an established risk factor for ischaemic stroke. The introduction of continuous cardiac rhythm monitoring devices has enabled detection of brief and asymptomatic episodes of AF.

Observations

The search yielded 727 studies, 11 of which met the inclusion criteria. Four studies suggested a strong temporal association between episodes of AF and stroke, while seven indicated a weak relationship. The conflicting nature of the studies may be attributed to inconsistencies in ischaemic stroke verification (n=5/11), event rate and power (n=6/11) and lack of controlling for anticoagulation (n=10/11), mitigating the relationship between AF episodes and stroke.

Conclusions and relevance

The temporal relationship between AF and stroke still remains unclear due to varying study methodology, lack of control for anticoagulation and inconsistent stroke subtyping. Our review identifies limitations to the current literature and makes recommendations for future studies assessing the temporal relationship between AF episodes and cardioembolic stroke.

Use of Anticoagulation for Thromboembolic Prophylaxis in Patients With Atrial High-Rate Episodes on Device Monitoring: A Narrative Review

Ischemic stroke and systemic thromboembolism are primary drivers of significant morbidity and mortality in patients with atrial fibrillation (AF). Although stroke is commonly the first index presentation of clinically silent AF, the growing use of continuous rhythm monitoring through cardiac implanted electronic devices has enabled earlier and increased detection of AF in patients who are otherwise asymptomatic before stroke development. Atrial high-rate episodes (AHREs) are atrial tachyarrhythmias frequently detected by cardiac implanted electronic devices; these events represent subclinical AF and other atrial tachyarrhythmias that can lead to stroke development and AF. Although the presence of AHREs increases the risk of developing both clinical AF and stroke compared with absence of AHREs, there has been a significant clinical variability in anticoagulation initiation in these subjects. In this narrative review, we explore the current evidence and published research surrounding the association between AHREs and stroke development in addition to the utility of anticoagulation in this population for thromboembolic prophylaxis.

Towards a new classification of atrial fibrillation detected after a stroke or a transient ischaemic attack

Globally, up to 1·5 million individuals with ischaemic stroke or transient ischaemic attack can be newly diagnosed with atrial fibrillation per year. In the past decade, evidence has accumulated supporting the notion that atrial fibrillation first detected after a stroke or transient ischaemic attack differs from atrial fibrillation known before the occurrence of as stroke. Atrial fibrillation detected after stroke is associated with a lower prevalence of risk factors, cardiovascular comorbidities, and atrial cardiomyopathy than atrial fibrillation known before stroke occurrence. These differences might explain why it is associated with a lower risk of recurrence of ischaemic stroke than known atrial fibrillation. Patients with ischaemic stroke or transient ischaemic attack can be classified in three categories: no atrial fibrillation, known atrial fibrillation before stroke occurrence, and atrial fibrillation detected after stroke. This classification could harmonise future research in the field and help to understand the role of prolonged cardiac monitoring for secondary stroke prevention with application of a personalised risk-based approach to the selection of patients for anticoagulation.

Apixaban versus Aspirin for Embolic Stroke of Undetermined Source

BACKGROUND: Rivaroxaban and dabigatran were not superior to aspirin in trials of patients with embolic stroke of undetermined source (ESUS). It is unknown whether apixaban is superior to aspirin in patients with ESUS and known risk factors for cardioembolism. METHODS: We conducted a multicenter, randomized, open-label, blinded-outcome trial of apixaban (5 mg twice daily) compared with aspirin (100 mg once daily) initiated within 28 days after ESUS in patients with at least one predictive factor for atrial fibrillation or a patent foramen ovale. Cardiac monitoring was mandatory, and aspirin treatment was switched to apixaban in case of atrial fibrillation detection. The primary outcome was any new ischemic lesion on brain magnetic resonance imaging (MRI) during 12-month follow-up. Secondary outcomes included major and clinically relevant nonmajor bleeding. RESULTS: A total of 352 patients were randomly assigned to receive apixaban (178 patients) or aspirin (174 patients) at a median of 8 days after ESUS. At 12-month follow-up, MRI follow-up was available in 325 participants (92.3%). New ischemic lesions occurred in 23 of 169 (13.6%) participants in the apixaban group and in 25 of 156 (16.0%) participants in the aspirin group (adjusted odds ratio, 0.79; 95% confidence interval, 0.42 to 1.48; P=0.57). Major and clinically relevant nonmajor bleeding occurred in five and seven participants, respectively (1-year cumulative incidences, 2.9 and 4.2; hazard ratio, 0.68; 95% confidence interval, 0.22 to 2.16). Serious adverse event rates were 43.9 per 100 person-years in those given apixaban and 45.7 per 100 person-years in those given aspirin. The Apixaban for the Treatment of Embolic Stroke of Undetermined Source trial was terminated after a prespecified interim analysis as a result of futility. CONCLUSIONS: Apixaban treatment was not superior to cardiac monitoring-guided aspirin in preventing new ischemic lesions in an enriched ESUS population. (Funded by Bristol-Myers Squibb and Medtronic Europe; ClinicalTrials.gov number, NCT02427126.)

Genetic Atrial Cardiomyopathies: Common Features, Specific Differences, and Broader Relevance to Understanding Atrial Cardiomyopathy

Atrial cardiomyopathy is a condition that causes electrical and contractile dysfunction of the atria, often along with structural and functional changes. Atrial cardiomyopathy most commonly occurs in conjunction with ventricular dysfunction, in which case it is difficult to discern the atrial features that are secondary to ventricular dysfunction from those that arise as a result of primary atrial abnormalities. Isolated atrial cardiomyopathy (atrial-selective cardiomyopathy [ASCM], with minimal or no ventricular function disturbance) is relatively uncommon and has most frequently been reported in association with deleterious rare genetic variants. The genes involved can affect proteins responsible for various biological functions, not necessarily limited to the heart but also involving extracardiac tissues. Atrial enlargement and atrial fibrillation are common complications of ASCM and are often the predominant clinical features. Despite progress in identifying disease-causing rare variants, an overarching understanding and approach to the molecular pathogenesis, phenotypic spectrum, and treatment of genetic ASCM is still lacking. In this review, we aim to analyze the literature relevant to genetic ASCM to understand the key features of this rather rare condition, as well as to identify distinct characteristics of ASCM and its arrhythmic complications that are related to specific genotypes. We outline the insights that have been gained using basic research models of genetic ASCM in vitro and in vivo and correlate these with patient outcomes. Finally, we provide suggestions for the future investigation of patients with genetic ASCM and improvements to basic scientific models and systems. Overall, a better understanding of the genetic underpinnings of ASCM will not only provide a better understanding of this condition but also promises to clarify our appreciation of the more commonly occurring forms of atrial cardiomyopathy associated with ventricular dysfunction.

Sinus node dysfunction and stroke risk: a systematic review and meta-analysis

OBJECTIVES

The role of cardiac arrhythmia in ischaemic stroke is widely studied, but the size of the stroke risk in patients with sinus node dysfunction (SND) with and without atrial fibrillation (AF) is unclear. This systematic review and meta-analysis aimed to compare the risk of stroke and its associated factors in patients with SND with and without AF.

DESIGN

A systematic review and meta-analysis was conducted based on the Grading of Recommendations, Assessment, Development and Evaluation approach.

DATA SOURCES

PubMed, EMBASE and Cochrane Database were searched until December 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that investigate stroke in patients with SND diagnosed with or without AF/atrial flutter.

DATA EXTRACTION AND SYNTHESIS

Two independent authors screened studies for inclusion and extracted data. Literature quality assessment was performed using the Newcastle-Ottawa Scale and the Cochrane Collaboration Tool. The overall risk of stroke was estimated using the random-effects model. The generic inverse variance method was used to calculate the pooled estimates of stroke-associated factors. We performed a sensitivity analysis using a fixed-effects model.

RESULTS

Of the 929 records retrieved, 6 papers (106 163 patients) met the inclusion criteria. The average yearly stroke incidence in patients with SND was 1.542% (95% CI: 1.334% to 1.749%). The stroke incidence was similar between the isolated SND (1.587%; 95% CI: 1.510% to 1.664%) and non-isolated (SND+AF) (1.660%; 95% CI: 0.705% to 2.615%) groups. AF (HR, 95% CI: 1.53 (1.01 to 2.33)), stroke/transient ischaemia attack/other thrombotic events (HR, 95% CI: 2.54 (1.14 to 5.69)), hypertension (HR, 95% CI: 1.51 (1.11 to 2.07)) and heart failure (HR, 95% CI: 1.41 (1.01 to 1.97)) were associated with stroke in the SND population.

CONCLUSION

Our findings suggest that patients with SND carry a similar risk of stroke to those with combined SND and AF. Future studies are needed to investigate whether interventions targeting stroke prevention, such as anticoagulation therapy, can help to prevent stroke in patients with SND.

PROSPERO REGISTRATION NUMBER

CRD42023408436.

Role of atrial high-rate episodes in stratifying thromboembolic risk: a multiple cut-off diagnostic meta-analysis

Aims

Despite the high prevalence rate of atrial high-rate episodes (AHREs) detected using cardiac implantable electronic devices (CIEDs), clinical guidelines and consensus documents have disagreed on a universal AHRE definition and a temporal cut-off related to subsequent thromboembolic events. This diagnostic test accuracy meta-analysis aims to derive the optimal temporal threshold of clinically significant AHREs from the available literature.

Methods

The PubMed/MEDLINE and EMBASE databases were screened for studies on CIED patients reporting the incidence of thromboembolic events related to at least one AHRE temporal cut-off. A total of 23 studies were included: 19 considering the longest single AHRE and four the AHRE burden, respectively. A random-effect diagnostic test accuracy meta-analysis with multiple cut-offs was performed. Two analyses were performed according to the AHRE temporal cut-off subtype (longest episode vs. cumulative burden).

Results

The analysis on the longest single AHRE indicated 0.07 min as the optimal duration to differentiate AHRE associated or not with thromboembolic events [sensitivity 65.4% (95% CI 48.8%-79.0%), specificity 52.7% (95% CI 46.0%-59.4%), and area under the summary receiver operating characteristic curve (AUC-SROC): 0.62]. The analysis on AHRE burden indicated 1.4 min as the optimal cut-off [sensitivity 58.2% (95% CI 25.6%-85.0%), specificity 57.5% (95% CI 42.0%-71.7%), and AUC-SROC 0.60]. A sensitivity analysis excluding patients with a history of atrial fibrillation and including high-quality studies only yielded similar results.

Conclusion

The presence of AHRE, rather than a specific duration, relates to an increased, albeit low, thromboembolic risk in CIED patients. Any AHRE should constitute an additional element in patient-specific thromboembolic risk assessment.

Progression of Device-Detected Atrial High-Rate Episodes and the Risk of All-Cause Mortality

Atrial high-rate episodes (AHREs) are prevalent in approximately 1/3 of patients with cardiac implanted electronic devices and are associated with an increased risk of several adverse outcomes. This study aimed to explore the factors associated with AHRE progression and the risk of all-cause mortality. At least 1 day with AHRE burden ≥15 minutes was identified in 124 of 343 recipients (36.2%) of an implantable cardioverter defibrillator or cardiac resynchronization therapy device. We included patients whose AHRE burden at the time of first detection was ≥15 minutes but <24 hours (n = 107). Various cut-off values (15 minutes, 6 hours, and 24 hours) of daily AHRE burden were analyzed. During an average follow-up of 4.2 years, 60 patients (56.1%) experienced ≥1 progression to greater AHRE burden. Patients with hypertension or greater AHRE burden at first detection were associated with faster progression. In addition, 27 deaths (45%) occurred among 60 patients with AHRE progression, compared with 25.5% (12 of 47) for those without progression. After multivariable adjustment, AHRE progression was independently associated with all-cause mortality (hazard ratio 2.56, 95% confidence interval 1.23 to 5.35, p = 0.012). Notably, AHRE progression within 1 month after their first detection was associated with an increased risk for all-cause mortality (hazard ratio 4.01, 95% confidence interval 1.76 to 9.16, p = 0.001) compared with patients without progression. However, a similar risk was not observed among patients with AHRE progression occurring after 1 month after their first detection. In conclusion, >1/2 of the patients with AHRE progressed to a greater burden over time. Continuous monitoring of the AHRE burden may help identify patients at great risk for death.

"Pill-in-Pocket" anticoagulation for stroke prevention in atrial fibrillation

Uninterrupted anticoagulation for atrial fibrillation (AF), regardless of AF burden, is deeply rooted in practice since the early anticoagulation trials. However, uninterrupted anticoagulation is not without risks, and may not be beneficial for allcomers with a history of AF. Indeed, contemporary data that support a critical duration threshold of AF that benefits from anticoagulation, and a temporal association between stroke and multihour AF episodes, compel the study of a more targeted approach to AF anticoagulation. In this review, we discuss data that support further investigation of "pill in the pocket" anticoagulation for AF, and introduce the pivotal Rhythm Evaluation for Anticoagulation Therapy for Atrial Fibrillation (REACT-AF) trial that will robustly evaluate this strategy.

2023 HRS/EHRA/APHRS/LAHRS expert consensus statement on practical management of the remote device clinic

Remote monitoring is beneficial for the management of patients with cardiovascular implantable electronic devices by impacting morbidity and mortality. With increasing numbers of patients using remote monitoring, keeping up with higher volume of remote monitoring transmissions creates challenges for device clinic staff. This international multidisciplinary document is intended to guide cardiac electrophysiologists, allied professionals, and hospital administrators in managing remote monitoring clinics. This includes guidance for remote monitoring clinic staffing, appropriate clinic workflows, patient education, and alert management. This expert consensus statement also addresses other topics such as communication of transmission results, use of third-party resources, manufacturer responsibilities, and programming concerns. The goal is to provide evidence-based recommendations impacting all aspects of remote monitoring services. Gaps in current knowledge and guidance for future research directions are also identified.

Remote monitoring of cardiac implantable electronic devices and disease management

This reviews the transition of remote monitoring of patients with cardiac electronic implantable devices from curiosity to standard of care. This has been delivered by technology evolution from patient-activated remote interrogations at appointed intervals to continuous monitoring that automatically flags clinically actionable information to the clinic for review. This model has facilitated follow-up and received professional society recommendations. Additionally, continuous monitoring has provided a new level of granularity of diagnostic data enabling extension of patient management from device to disease management. This ushers in an era of digital medicine with wider applications in cardiovascular medicine.

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

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

Association of Atrial Fibrillation With Stroke and Dementia Accounting for Left Atrial Function and Size

BACKGROUND

Atrial fibrillation (AF) is associated with higher risks of ischemic stroke (IS) and dementia. Whether alterations in left atrial (LA) function or size-atrial myopathy-confound these associations remains unknown.

OBJECTIVES

The purpose of this study was to examine the association of prevalent and incident AF with ischemic stroke and dementia in the ARIC (Atherosclerosis Risk In Communities) study, adjusting for LA function and size.

METHODS

Participants at visit 5 (2011-2013) with echocardiographic LA function (reservoir, conduit, contractile strain, and emptying fraction) and size (maximal, minimal volume index) data, and without prevalent stroke or dementia were followed through 2019. For analysis, we used time-varying Cox regression.

RESULTS

Among 5,458 participants (1,193 with AF, mean age of 76 years) in the stroke analysis and 5,461 participants (1,205 with AF, mean age of 75 years) in the dementia analysis, 209 participants developed ischemic stroke, and 773 developed dementia over 7.1 years (median). In a demographic and risk factor-adjusted model, AF was significantly associated with ischemic stroke (HR, 1.63; 95% CI: 1.11-2.37) and dementia (HR: 1.38, 95% CI: 1.13-1.70). After additionally adjusting for LA reservoir strain, these associations were attenuated and no longer statistically significant (stroke [HR: 1.33, 95% CI: 0.88-2.00], dementia [HR: 1.15, 95% CI: 0.92-1.43]). Associations with ischemic stroke and dementia were also attenuated and not statistically significant after adjustment for LA contractile strain, emptying fraction, and minimal volume index.

CONCLUSIONS

AF-ischemic stroke and AF-dementia associations were not statistically significant after adjusting for measures of atrial myopathy. This proof-of-concept analysis does not support AF as an independent risk factor for ischemic stroke and dementia.

Advances in basic and translational research in atrial fibrillation

Atrial fibrillation (AF) is a very common cardiac arrhythmia with an estimated prevalence of 33.5 million patients globally. It is associated with an increased risk of death, stroke and peripheral embolism. Although genetic studies have identified a growing number of genes associated with AF, the definitive impact of these genetic findings is yet to be established. Several mechanisms, including electrical, structural and neural remodelling of atrial tissue, have been proposed to contribute to the development of AF. Despite over a century of exploration, the molecular and cellular mechanisms underlying AF have not been fully established. Current antiarrhythmic drugs are associated with a significant rate of adverse events and management of AF using ablation is not optimal, especially in cases of persistent AF. This review discusses recent advances in our understanding and management of AF, including new concepts of epidemiology, genetics and pathophysiological mechanisms. We review the current status of antiarrhythmic drug therapy for AF, new potential agents, as well as mechanism-based AF ablation. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.

2023 HRS/EHRA/APHRS/LAHRS Expert Consensus Statement on Practical Management of the Remote Device Clinic

Remote monitoring is beneficial for the management of patients with cardiovascular implantable electronic devices by impacting morbidity and mortality. With increasing numbers of patients using remote monitoring, keeping up with higher volume of remote monitoring transmissions creates challenges for device clinic staff. This international multidisciplinary document is intended to guide cardiac electrophysiologists, allied professionals, and hospital administrators in managing remote monitoring clinics. This includes guidance for remote monitoring clinic staffing, appropriate clinic workflows, patient education, and alert management. This expert consensus statement also addresses other topics such as communication of transmission results, use of third-party resources, manufacturer responsibilities, and programming concerns. The goal is to provide evidence-based recommendations impacting all aspects of remote monitoring services. Gaps in current knowledge and guidance for future research directions are also identified.

Optimizing Anticoagulation Management in Atrial Fibrillation: Beyond the Guidelines. How and for Whom?

ABSTRACT

Anticoagulation therapy (AT) is the cornerstone of atrial fibrillation (AF) treatment for thromboembolic event prevention. The AF burden, however, is of predictive relevance and may be used as a foundation for therapeutic decisions in individuals with paroxysmal or persistent AF. Remote rhythm monitoring devices can provide early detection of the arrhythmia, long-term rhythm monitoring, and the development of anticoagulation strategies based on AF recurrence profile and the total burden of the arrhythmia. Although the exact thromboembolic cut-off value for the AF burden has not yet been established, targeted anticoagulation treatments in the new oral anticoagulants era have shown encouraging outcomes. The combined evaluation of AF burden and patient thromboembolic risk reported in some studies supports the concept of tailored anticoagulation management, at least in a subset of patients with low AF burden and intermediate thromboembolic risk, for whom the guidelines recommend that AT should be individualized based on net clinical benefit and patient values and preferences. Although it is still premature to derive firm conclusions or algorithms diverging from the current guidelines, the combination of a patient's AF burden, thromboembolic risk, and bleeding risk can lead in the future to an individualized management of patients with a congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke, vascular disease, age 65-74 years sex category (female) (CHA 2 DS 2 -VASc) score of 1 (2 for female patients), in whom the guidelines do not strictly recommend long-term AT. In this study, we provide an algorithm regarding the individualized implementation of anticoagulation strategies in AF in different patients' thromboembolic risk profiles, based on the available data on the so far tailored anticoagulation strategies in AF.

2023 HRS/EHRA/APHRS/LAHRS Expert Consensus Statement on Practical Management of the Remote Device Clinic

Remote monitoring is beneficial for the management of patients with cardiovascular implantable electronic devices by impacting morbidity and mortality. With increasing numbers of patients using remote monitoring, keeping up with higher volume of remote monitoring transmissions creates challenges for device clinic staff. This international multidisciplinary document is intended to guide cardiac electrophysiologists, allied professionals, and hospital administrators in managing remote monitoring clinics. This includes guidance for remote monitoring clinic staffing, appropriate clinic workflows, patient education, and alert management. This expert consensus statement also addresses other topics such as communication of transmission results, use of third-party resources, manufacturer responsibilities, and programming concerns. The goal is to provide evidence-based recommendations impacting all aspects of remote monitoring services. Gaps in current knowledge and guidance for future research directions are also identified.

Ability to remotely monitor atrial high-rate episodes using a single-chamber implantable cardioverter-defibrillator with a floating atrial sensing dipole

AIMS

To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend remote monitoring (RM) of device-detected atrial high-rate episodes (AHREs) and progression of arrhythmia duration along pre-specified strata (6 min…<1 h, 1 h…<24 h, ≥ 24 h). We used the MATRIX registry data to assess the capability of a single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (DX ICD system) to follow this recommendation in patients with standard indication for single-chamber ICD.

METHODS AND RESULTS

In 1841 DX ICD patients with daily automatic RM transmissions, electrograms of first device-detected AHREs per patient in each duration stratum were adjudicated, and the corresponding positive predictive values (PPVs) for the detections to be true atrial arrhythmia were calculated. Moreover, the incidence and progression of new-onset AF was assessed in 1451 patients with no AF history. A total of 610 AHREs ≥6 min were adjudicated. The PPV was 95.1% (271 of 285) for episodes 6min…<1 h, 99.6% (253/254) for episodes 1 h…<24 h, 100% (71/71) for episodes ≥24 h, or 97.5% for all episodes (595/610). The incidence of new-onset AF was 8.2% (119/1451), and in 31.1% of them (37/119), new-onset AF progressed to a higher duration stratum. Nearly 80% of new-onset AF patients had high CHA2DS2-VASc stroke risk, and 70% were not on anticoagulation therapy. Age was the only significant predictor of new-onset AF.

CONCLUSION

A 99.7% detection accuracy for AHRE ≥1 h in patients with DX ICD systems in combination with daily RM allows a reliable guideline-recommended screening for subclinical AF and monitoring of AF-duration progression.

Predicting Malignant Ventricular Arrhythmias Using Real-Time Remote Monitoring

BACKGROUND

Although implantable cardioverter-defibrillator (ICD) therapies are associated with increased morbidity and mortality, the prediction of malignant ventricular arrhythmias has remained elusive.

OBJECTIVES

The purpose of this study was to evaluate whether daily remote-monitoring data may predict appropriate ICD therapies for ventricular tachycardia or ventricular fibrillation.

METHODS

This was a post hoc analysis of IMPACT (Randomized trial of atrial arrhythmia monitoring to guide anticoagulation in patients with implanted defibrillator and cardiac resynchronization devices), a multicenter, randomized, controlled trial of 2,718 patients evaluating atrial tachyarrhythmias and anticoagulation for patients with heart failure and ICD or cardiac resynchronization therapy with defibrillator devices. All device therapies were adjudicated as either appropriate (to treat ventricular tachycardia or ventricular fibrillation) or inappropriate (all others). Remote monitoring data in the 30 days before device therapy were utilized to develop separate multivariable logistic regression and neural network models to predict appropriate device therapies.

RESULTS

A total of 59,807 device transmissions were available for 2,413 patients (age 64 ± 11 years, 26% women, 64% ICD). Appropriate device therapies (141 shocks, 10 antitachycardia pacing) were delivered to 151 patients. Logistic regression identified shock lead impedance and ventricular ectopy as significantly associated with increased risk of appropriate device therapy (sensitivity 39%, specificity 91%, AUC: 0.72). Neural network modeling yielded significantly better (P < 0.01 for comparison) predictive performance (sensitivity 54%, specificity 96%, AUC: 0.90), and also identified patterns of change in atrial lead impedance, mean heart rate, and patient activity as predictors of appropriate therapies.

CONCLUSIONS

Daily remote monitoring data may be utilized to predict malignant ventricular arrhythmias in the 30 days before device therapies. Neural networks complement and enhance conventional approaches to risk stratification.

[Asymptomatic atrial fibrillation : Screening and therapy]

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people worldwide and poses a significant burden to the health care system. AF screening of the general population or of a specific higher-risk population could not only lead to earlier detection of AF but also to a prompt initiation of an adequate therapy to prevent complications such as stroke or death and consecutively to a potential reduction of health care costs, especially in asymptomatic AF patients. To conduct screening programs, accessible new technology devices such as "wearables", smartwatches, and implantable event recorders provide an innovative solution. However, as data regarding screening are inconclusive, routine AF screening of the population is currently not recommended by the European Society of Cardiology. Recently published studies have indicated that anticoagulation and early rhythm control of asymptomatic AF could avoid occurrence of clinical endpoints. This article reports on the scientific results of the current literature as well as gaps of evidence and discusses possible treatment options of asymptomatic AF.

Atrial Fibrillation: a Marker or Risk Factor for Stroke

Atrial fibrillation (AF) is strongly associated with stroke risk, but an association by itself does not necessarily imply causation. The question remains whether AF is a risk factor for stroke and whether treatment that reduces the severity of AF will also reduce the burden of stroke. On the other hand, it is possible that AF is a risk marker associated with atrial insufficiency, in which structural and electrical atrial remodeling coexist, leading  to the clinical manifestations of AF and the risk of stroke simultaneously. Atrial fibrillation and stroke are inextricably linked to the classic Virchow pathophysiology, which explains thromboembolism as blood stasis in a fibrillating left atrium. This concept has been reinforced by the proven efficacy of oral anticoagulants for the prevention of stroke in AF. However, a number of observations showing that the presence of AF is neither necessary nor sufficient for stroke cast doubt on the causal role of AF in vascular brain injury. The growing recognition of the role of atrial cardiomyopathy and the atrial substrate in the development of stroke associated with AF, as well as stroke without AF, has led to a rethinking of the pathogenetic model of cardioembolic stroke. A number of recent studies have shown that AF is a direct cause of stroke. Studies in which cardiac implantable devices have been used to collect data on pre-stroke AF do not appear to show a direct time relationship. The presence of AF is neither necessary nor sufficient for stroke, which casts doubt on the causal role of AF in cerebrovascular injury. Known risk factors for stroke in the presence of AF are also recognized risk factors for ischemic stroke, regardless of the presence of AF. The risk of stroke in patients with AF in the absence of risk factors differs little from that in patients without AF. This work is devoted to an attempt to answer the question whether AF is a marker or a risk factor for ischemic stroke.

'Pill-in-the-pocket' Oral Anticoagulation Guided by Daily Rhythm Monitoring for Stroke Prevention in Patients with AF: A Systematic Review and Meta-analysis

Aims

In patients with a low AF burden and long periods of sinus rhythm, 'pill-in-the-pocket' oral anticoagulation (OAC) may, taken as needed in response to AF episodes, offer the same thromboembolic protection as continuous, life-long OAC, while reducing bleeding complications at the same time. The purpose of this study is to systematically summarise available evidence pertaining to the feasibility, safety and efficacy of pill-in-the-pocket OAC.

Methods

Medline and Embase were searched from inception to July 2022 for studies adopting a pill-in-the-pocket OAC strategy in AF patients guided by daily rhythm monitoring (PROSPERO/CRD42020209564). Outcomes of interest were extracted and event rates per patient-years of follow-up were calculated. A random effects model was used for pooled estimates.

Results

Eight studies were included (711 patients). Daily rhythm monitoring was continuous in six studies and intermittent in two (pulse checks or smartphone single-lead electrocardiograms were used). Anticoagulation criteria varied across studies, reflecting the uncertainty regarding the AF burden that warrants anticoagulation. The mean time from AF meeting OAC criteria to its initiation was not reported. Adopting pill-in-the-pocket OAC led to 390 (54.7%) patients stopping OAC, 85 (12.0%) patients taking pill-in-the-pocket OAC and 237 (33.3%) patients remaining on or returning to continuous OAC. Overall, annualised ischaemic stroke and major bleeding rates per patient-year of follow-up were low at 0.005 (95% CI [0.002-0.012]) and 0.024 (95% CI [0.013-0.043]), respectively.

Conclusion

Current evidence, although encouraging, is insufficient to inform practice. Additional studies are required to improve our understanding of the relationships between AF burden and thromboembolic risk to help define anticoagulation criteria and appropriate monitoring strategies.

New electrocardiographic aspects of the P wave: Its value in clinical cardiology

In this article, we will comment on new aspects of P-wave morphology that help us to better diagnose atrial blocks and atrial enlargement, and their clinical implications. These include: (1) Atypical ECG patterns of advanced interatrial block; (2) The ECG diagnosis of left atrial enlargement versus interatrial block; (3) Atrial fibrillation and advanced interatrial block: The two sides of the same coin; and (4) P-wave parameters: Clinical implications.

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.

Atrial cardiomyopathy: Diagnosis, clinical implications and unresolved issues in anticoagulation therapy

Atrial cardiomyopathy (AC) is an evolving pathophysiological entity that has expanded our understanding regarding the atrium and its role in arrhythmogenesis and cardiac thromboembolism. The pathological myocardium in AC promotes arrhythmogenesis through mechanical dysfunction (hypocontractility, fibrosis), adverse alterations of the endothelium and secretion of prothrombotic factors (IL-6, IL-8, TNF-a). 'Red flags', indicative of AC, can be recognized either non-invasively by electrocardiography, echocardiography and cardiac magnetic resonance imaging or invasively by high-density electroanatomical mapping as low bipolar voltage areas of the affected myocardium. Signs of AC have been strongly associated with an increased risk of ischemic stroke, even embolic strokes of undetermined source, regardless of the coexistence of atrial fibrillation (AF). The underlying existence of AC has been negatively correlated with the success rate of catheter ablation of AF. The clinical value of AC is the provision of a novel pathway regarding the potential mechanisms of cerebrovascular events of cardiac thromboembolic origin. In addition, AC may serve as a risk stratification tool to predict the long-term responders of AF catheter ablation.

Atrial fibrillation and stroke

INTRODUCTION

Stroke is one of the leading causes of mortality and morbidity globally. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It is set to reach epidemic proportions. AF is associated with a five-fold increase in risk of stroke. Strokes caused by AF more often are fatal or result in severe disability. Even though the incidence of stroke has been significantly reduced by oral anticoagulation, AF is thought to account for a significant proportion of cryptogenic strokes where no etiology is identified.

AREAS COVERED

This article reviews the literature related to AF and stroke, pathophysiological insights, diagnosis of AF in stroke patients, and its management (Graphical Abstract).

EXPERT OPINION

The pathophysiology of thrombogenesis that links AF and stroke is not well understood and is an area of active research to identify new therapeutic targets to prevent AF and stroke. As the nature of AF and stroke is multifaceted, an integrated care approach to managing AF and stroke is increasingly essential.

Implantable loop recorders in patients with atrial fibrillation

INTRODUCTION

Implantable loop recorders (ILRs) provide practitioners with high-quality electrocardiographic data over an extended monitoring period. These data can guide the diagnosis and management of patients with atrial fibrillation (AF).

AREAS COVERED

This review summarizes the available evidence and consensus statements supporting the use of ILRs in the detection of AF, as well as monitoring of patients with known AF. Future directions for research are also discussed.

EXPERT OPINION

ILRs are the gold standard for detecting AF, providing superior diagnostic yield compared to other modes of ambulatory electrocardiography monitoring. Both experimental evidence and consensus statements support the use of ILRs in clinical settings where the diagnosis of AF may significantly change management, or where a high degree of sensitivity is needed. ILRs may also be used to monitor patients following AF ablation. More evidence is needed to better inform how ILR-detected AF should change management.

Atrial cardiomyopathy markers predict ischemic cerebrovascular events independent of atrial fibrillation in patients with acute myocardial infarction

Background

Contemporary data on atrial cardiomyopathy (ACM) markers and ischemic cerebrovascular events (ICVE) in patients with acute myocardial infarction (AMI) is lacking. We aimed to examine whether ACM markers predict ICVE among AMI patients.

Materials and methods

A total of 4,206 AMI cases diagnosed in clinical examinations between January 2016 and June 2021 were assessed for markers of ACM including B-type natriuretic peptide (BNP), P-wave terminal force in ECG lead V1 (PTFV1), and left atrium diameter (LAD). Left atrial enlargement (LAE) and abnormal PTFV1 were defined by previously published cut-off points. The primary outcome was incident ICVE composed of ischemic stroke (IS) and transient ischemic attack (TIA). Receiver operating curve analyses were used to compare the predictive performance of the CHA2DS2-VASc score combined with ACM markers to the CHA2DS2-VASc score alone.

Results

During a median follow-up of 44.0 months, 229 (5.44%) ICVE occurred. Of these, 156 individuals developed IS and the remaining 73 cases were diagnosed with TIAs. The ICVE group showed larger PTFV1 and increased LAD as well as elevated BNP levels at baseline. In the multivariate analysis, we found significant associations with ICVE for PTFV1 (HR per 1,000 μV*ms, 1.143; 95% CI, 1.093–1.196), LAD (HR per millimeter, 1.148; 95% CI, 1.107–1.190), but not BNP after adjusting for known ICVE risk factors and interim atrial fibrillation (AF). The addition of abnormal PTFV1 and LAE improved the predictive accuracy of the CHA2DS2-VASc score with C-statistic increasing from 0.708 to 0.761 (p &lt; 0.001).

Conclusion

Atrial cardiomyopathy markers including PTFV1 and LAD were associated with incident ICVE independent of well-established risk factors and AF occurrence. The addition of ACM markers with CHA2DS2-VASc score may well discriminate individuals at high risk of ICVE in AMI patients.

Atrial Fibrillation, thromboembolic risk, and the potential role of the natriuretic peptides, a focus on BNP and NT-proBNP - A narrative review

Atrial fibrillation (AF) is one of the most commonly encountered arrythmia in clinical practice. AF itself can be driven by genetic predisposition, ectopic electrical activity, and abnormal atrial tissue substrates. Often there is no single etiological mechanism, but rather a combination of factors that feed back to remodel and worsen tissue substrate, "AF begets AF". The clinical consequences of AF can often include emboli, heart failure, and early mortality. The classical AF cardioembolic (CE) concept requires thrombus formation in the left atrial appendage, with subsequent embolization. The temporal dissociation between AF occurrence and CE events has thrown doubt on AF as the driver of this mechanism. Instead, there has been a resurgence of the "atrial cardiomyopathy" (ACM) concept. An ACM is proposed as a potential mechanism of embolic disease through promotion of prothrombotic mechanisms, with AF instead reflecting atrial disease severity. Regardless, AF has been implicated in 25% to 30% of cryptogenic strokes. Natriuretic peptide(NP)s have been shown to be elevated in AF, with higher levels of both NT-proBNP and BNP being predictive of incidental AF. NPs potentially reflect the atrial environment and could be used to identify an underlying ACM. Therefore, this narrative review examines this evidence and mechanisms that may underpin the role of NPs in identifying atrial dysfunction, with focus on both, BNP and NTproBNP. We explore their potential role in the prediction and screening for both, ACM and AF. Moreover, we compare both NPs directly to ascertain a superior biomarker.

Atrial fibrillation: focus on monitoring strategies after cryptogenic stroke

Atrial fibrillation (AF) is responsible for up to one-third of ischemic strokes, with stroke potentially being the first manifestation of a previously undetected AF. Given the efficacy of oral anticoagulants in preventing AF-related ischemic events, searching for unknown AF after stroke requires a comprehensive diagnostic workup. Prospective data have demonstrated the benefits of long-term cardiac monitoring to identify AF in association with cryptogenic stroke, as most strokes are presumed to result from AF. However, strategies of empirical anticoagulation using oral anticoagulants following cryptogenic stroke failed to improve outcomes. We herein summarize contemporary evidence and knowledge gaps on searching for AF after a stroke and the potential secondary prevention strategies to prevent further recurrences.

ESC Working Group on e-Cardiology Position Paper: accuracy and reliability of electrocardiogram monitoring in the detection of atrial fibrillation in cryptogenic stroke patients : In collaboration with the Council on Stroke, the European Heart Rhythm Association, and the Digital Health Committee

The role of subclinical atrial fibrillation as a cause of cryptogenic stroke is unambiguously established. Long-term electrocardiogram (ECG) monitoring remains the sole method for determining its presence following a negative initial workup. This position paper of the European Society of Cardiology Working Group on e-Cardiology first presents the definition, epidemiology, and clinical impact of cryptogenic ischaemic stroke, as well as its aetiopathogenic association with occult atrial fibrillation. Then, classification methods for ischaemic stroke will be discussed, along with their value in providing meaningful guidance for further diagnostic efforts, given disappointing findings of studies based on the embolic stroke of unknown significance construct. Patient selection criteria for long-term ECG monitoring, crucial for determining pre-test probability of subclinical atrial fibrillation, will also be discussed. Subsequently, the two major classes of long-term ECG monitoring tools (non-invasive and invasive) will be presented, with a discussion of each method's pitfalls and related algorithms to improve diagnostic yield and accuracy. Although novel mobile health (mHealth) devices, including smartphones and smartwatches, have dramatically increased atrial fibrillation detection post ischaemic stroke, the latest evidence appears to favour implantable cardiac monitors as the modality of choice; however, the answer to whether they should constitute the initial diagnostic choice for all cryptogenic stroke patients remains elusive. Finally, institutional and organizational issues, such as reimbursement, responsibility for patient management, data ownership, and handling will be briefly touched upon, despite the fact that guidance remains scarce and widespread clinical application and experience are the most likely sources for definite answers.

Deep terminal negativity of the P-wave in V1 and stroke risk: The National Health and Nutrition Examination survey III

Background

Deep terminal negativity of the P‐wave in V1 (DTNPV1) was considered if the absolute value of the depth of the negative phase was >100 μV in the presence of a biphasic P‐wave in V1. In this study, we aimed to determine the association between DTNPV1, a simpler P‐wave index, and the risk of stroke.

Methods

We compared P‐wave indices between participants with and without a self‐reported history of stroke in the United States Third National Health and Nutrition Examination Survey (NHANES III). The association between DTNPV1 and stroke was quantified with logistic regression models.

Results

In total, 7732 participants were included (307 with a history of stroke). Patients with stroke had deeper terminal negativity of the P‐wave in V1 (52.3 ± 33.9 μV vs. 41.4 ± 27.0 μV, p < .001). After adjustment, DTNPV1 was associated with an increased risk of stroke (OR: 1.63, 95% CI: 1.03–2.60, p = .038). This association appeared to be stronger in people aged <75 years (interaction p = .023), and in those without heart failure (interaction p = .018) or ischemic heart disease (interaction p = .014). In contrast to the participants with 0 or ≥2 risk factors, in those with 1 risk factor, stroke prevalence was significantly different among the three categories of terminal negativity of the P‐wave (0 μV, >0 μV but ≤100 μV and > 100 μV) in V1 (2.8%, 3.3%, and 10.3%, respectively, p = .005).

Conclusion

In NHANES III, DTNPV1 was associated with a higher prevalence of stroke, suggesting that DTNPV1 might be a convenient marker to distinguish the risk of stroke.

Prevalence of markers of atrial cardiomyopathy in embolic stroke of undetermined source: A systematic review

BACKGROUND

Emerging evidence suggests the potential role of atrial cardiomyopathy (AC) as a direct thromboembolic determinant in embolic stroke of undetermined source (ESUS).

OBJECTIVE

We aimed to quantify the prevalence of potential AC markers among ESUS, non-cardioembolic (NCE) and cardioembolic (CE) stroke patients.

METHODS

PubMed and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched for publications from inception to October 2021, with duplicate data extraction and risk of bias assessment. The Newcastle-Ottawa assessment scale was used to evaluate study quality.

RESULTS

Among 398 screened studies, 11 observational studies with 2009 ESUS patients (mean age 66.5 years) fulfilled the inclusion criteria. Of electrocardiographic markers, increased P-wave terminal force in lead V1 was more prevalent in ESUS vs NCE (OR=2.26, 95%CI: 1.40-3.66). Of imaging markers, left atrial volume index (LAVI) and left atrial diameter (LAd) were higher in ESUS vs NCE (OR=1.04, 95%CI: 1.02-1.06 and OR=3.41, 95%CI: 1.35-8.61 respectively). Non-chicken wing morphology of the left atrial appendage was more frequent in ESUS compared to NCE patients in the majority of studies. Of serum biomarkers, the prevalence of NT-proBNP >250 pg/ml did not differ among ESUS vs NCE (OR=0.73, 95%CI: 0.39 -1.35).

CONCLUSIONS

Electrocardiographic, echocardiographic markers and advanced imaging modalities able to assess the morphologic characteristics of left atrial appendage and left atrial function may be important tools to discriminate AC among ESUS vs NCE stroke patients. Prospective studies exploring the association of potential AC markers with ESUS occurrence are warranted to validate their clinical utility.

Atrial CARdiac Magnetic resonance imaging in patients with embolic stroke of unknown source without documented Atrial Fibrillation (CARM-AF): Study design and clinical protocol

Background

Initiation of anticoagulation therapy in ischemic stroke patients is contingent on a clinical diagnosis of atrial fibrillation (AF). Results from previous studies suggest thromboembolic risk may predate clinical manifestations of AF. Early identification of this cohort of patients may allow early initiation of anticoagulation and reduce the risk of secondary stroke.

Objective

This study aims to produce a substrate-based predictive model using cardiac magnetic resonance imaging (CMR) and baseline noninvasive electrocardiographic investigations to improve the identification of patients at risk of future thromboembolism.

Methods

CARM-AF is a prospective, multicenter, observational cohort study. Ninety-two patients will be recruited following an embolic stroke of unknown source (ESUS) and undergo atrial CMR followed by insertion of an implantable loop recorder (ILR) as per routine clinical care within 3 months of index stroke. Remote ILR follow-up will be used to allocate patients to a study or control group determined by the presence or absence of AF as defined by ILR monitoring.

Results

Baseline data collection, noninvasive electrocardiographic data analysis, and imaging postprocessing will be performed at the time of enrollment. Primary analysis will be performed following 12 months of continuous ILR monitoring, with interim and delayed analyses performed at 6 months and 2 and 3 years, respectively.

Conclusion

The CARM-AF Study will use atrial structural and electrocardiographic metrics to identify patients with AF, or at high risk of developing AF, who may benefit from early initiation of anticoagulation.

Atrial High-Rate Episodes Detected by Cardiac Implantable Electronic Devices: Dynamic Changes in Episodes and Predictors of Incident Atrial Fibrillation

Simple Summary

Atrial high rate episodes (AHRE) detected by cardiac implantable electronic devices (CIEDs) may be associated with a risk of progression towards long-lasting episodes (≥24 h) and clinical atrial fibrillation (AF). Identification of this subset of patients is key to promptly starting oral anticoagulant therapy and possibly avoiding stroke and systemic thromboembolism. In the present study, we describe the clinical characteristics of 104 retrospectively enrolled patients with AHRE episodes lasting 5 min–23 h 59 min, no AF at 12-lead ECG, and no history of prior clinical AF. Moreover, we define predictors of the composite outcome of clinical AF and/or AHRE episodes lasting ≥24 h. Over a median follow-up of 24.3 (10.6–40.3) months, 31/104 (29.8%) patients experienced the composite outcome. Baseline CHA₂DS₂-VASc score and the longest AHRE episode at enrollment lasting 12 h–23 h 59 min were independently associated with the composite outcome and with incident clinical AF as well. To conclude, in patients with AHRE, the incidence of clinical AF or AHRE episodes lasting ≥24 h is high. Baseline patients’ characteristics (CHA₂DS₂-VASc score) and AHRE duration may help to intensify monitoring and decision-making, being independently associated with clinical AF in a two-year follow-up.

Abstract

Background. Atrial high rate episodes (AHRE) detected by cardiac implantable electronic devices (CIEDs) may be associated with a risk of progression towards long-lasting episodes (≥24 h) and clinical atrial fibrillation (AF). Methods. Consecutive CIED patients presenting AHRE (with confirmation of an arrhythmia lasting 5 min–23 h 59 min, atrial rate ≥175/min, with no AF at 12-lead ECG and no prior clinical AF) were retrospectively enrolled. The aims of this study were to describe patients’ characteristics and the incidence of adverse events, and second, to identify potential predictors of the composite outcome of clinical AF and/or AHRE episodes lasting ≥24 h. Results. 104/107 (97.2%) patients (median age 79.7 (74.0–84.2), 33.7% female) had available follow-up data. Over a median follow-up of 24.3 (10.6–40.3) months, 31/104 (29.8%) patients experienced the composite outcome of clinical AF or AHRE episodes lasting ≥24 h. Baseline CHA₂DS₂-VASc score and the longest AHRE episode at enrollment lasting 12 h–23 h 59 min were independently associated with the composite outcome (Hazard ratio (HR); 95% CI: 1.40; 1.07–1.83 and HR: 8.15; 95% CI 2.32–28.65, respectively). Baseline CHA₂DS₂-VASc score and the longest AHRE episode at enrollment lasting 12 h–23 h 59 min were the only independent predictors of incident clinical AF (HR: 1.45; 95% CI 1.06–2.00 and HR: 4.25; 95% CI 1.05–17.20, respectively). Conclusions. In patients with AHRE, the incidence of clinical AF or AHRE episodes lasting ≥24 h is high in a two-year follow-up. Baseline patients’ characteristics (CHA₂DS₂-VASc score) and AHRE duration may help to intensify monitoring and decision-making, being independently associated with clinical AF at follow-up.

Use of Prolonged Cardiac Rhythm Monitoring to Identify Atrial Fibrillation After Cryptogenic Stroke

PURPOSE OF REVIEW

Prolonged cardiac monitoring (PCM) improves detection of atrial fibrillation (AF) after cryptogenic stroke. We summarize current research supporting the use of PCM as part of the cryptogenic stroke evaluation, while highlighting areas that require more investigation.

RECENT FINDINGS

Despite increased AF detection with longer durations of PCM, more definitive research is needed to demonstrate how PCM improves clinical outcomes. The optimal type, timing, and length of cardiac monitoring after cryptogenic stoke remains unknown. Clinical calculators will be important to risk stratify which cryptogenic stroke patients are most likely to benefit from PCM. Currently, AF detection after cryptogenic stroke should prompt consideration of anticoagulation, but it is unclear if all durations and timing of AF after stroke should be treated the same. PCM remains an important part of the cryptogenic stroke work up, and detection of AF allows for anticoagulation initiation. Additional research is needed to further refine our application of PCM to cryptogenic stroke.