Uncovering Atrial Fibrillation Beyond Short-Term Monitoring in Cryptogenic Stroke Patients: Three-Year Results From the Cryptogenic Stroke and Underlying Atrial Fibrillation Trial

Efficacy and clinical implications of a stepwise screening strategy for atrial fibrillation after stroke: Insights from the SAFAS study

BACKGROUND

Although guidelines recommend screening patients for atrial fibrillation (AF) after stroke, the optimal timing and combination of screening tools remain unclear.

AIMS

We evaluated the suitability of a sequential combination of screening techniques for AF detected after stroke (AFDAS). We also compared patient characteristics according to the timing of AFDAS.

METHODS

Patients without previous AF admitted for acute ischaemic stroke were prospectively enrolled. After a stepwise screening approach for AFDAS based on electrocardiogram, telemetry monitoring and in-hospital long-term Holter, patients with cryptogenic stroke underwent implantation of an implantable cardiac monitor (ICM). Early AFDAS was defined as AF diagnosed during hospitalization and late AFDAS as AF diagnosed on an ICM.

RESULTS

Of the 240 patients included, 104 (43.3%) had a documented cause of stroke not related to AF. Among the 136 remaining patients, AFDAS was detected in 82 (60.3%) during the acute screening phase or during the 3-year follow-up by ICM. Early AFDAS was diagnosed by ECG, telemetry and in-hospital long-term Holter monitoring in 17 (20.7%), 25 (30.5%) and 18 (22.0%) patients, respectively. Among 76 patients who had an ICM implanted for cryptogenic stroke, AF was detected in 22 patients (28.9%). Except for age and stroke location, patients with early AFDAS did not differ from those with late AFDAS, particularly with regard to the prevalence of atrial cardiomyopathy markers.

CONCLUSION

A stepwise approach to AFDAS screening allows early detection of AF in a considerable number of patients during their hospitalization. ICMs remain complementary to non-invasive screening tools for the detection of remote episodes of AF.

Incidence and nationwide estimates of cryptogenic ischemic stroke or TIA eligible for prolonged cardiac rhythm monitoring

INTRODUCTION

Current guidelines indicate prolonged cardiac rhythm monitoring for atrial fibrillation screening in patients with cryptogenic ischemic stroke (IS) or transient ischemic attack (TIA). This study aimed to assess the incidence of cryptogenic IS/TIA eligible for such investigation, and to estimate the number of patients potentially concerned in whole France annually.

METHODS

All cryptogenic acute IS/TIA cases ⩾35 years old were retrieved from the population-based Dijon Stroke Registry, France (2013-2020). Patients eligible for prolonged cardiac rhythm monitoring were defined after excluding those who died in-hospital or within the first 30 days, or with preexisting major impairment. Annual incidence rates of eligible cryptogenic IS/TIA were calculated by age groups and sex. The total number of eligible patients in France was estimated by standardization to age- and sex-specific incidence.

RESULTS

Among 2811 IS/TIA patients recorded in the Dijon Stroke Registry, 1239 had cryptogenic IS/TIA of whom 1045 were eligible for prolonged cardiac rhythm monitoring (517 IS and 528 TIA, mean age 73.6 ± 14.6 years old, 55.4% women). Crude incidence rates of eligible cryptogenic IS/TIA were 169/100,000 per year (95% CI: 159-179) in overall sexes, 83/100,000 per year (95% CI: 76-91) for IS, and 85/100,000 per year (95% CI: 78-93) for TIA. The total number of patients with cryptogenic IS/TIA eligible for prolonged cardiac rhythm monitoring in France was estimated to be 66,125 (95% CI: 65,622-66,630) for the calendar year 2022, including 32,764 (95% CI: 32,410-33,120) with IS and 33,361 (95% CI: 33,004-33,721) with TIA.

CONCLUSIONS

This study demonstrated a high incidence of cryptogenic IS/TIA eligible for prolonged cardiac rhythm monitoring. Estimates at a national level pointed out the large number of patients who may require access to such atrial fibrillation screening, with attention to be paid on regarding organization of care networks and related costs.

Challenges and advances in device-related thrombus in left atrial appendage occlusion

Oral anticoagulation therapy (OAC) is a mainstay for mitigating stroke and other embolic events in patients with atrial fibrillation (AF). Despite the demonstrated efficacy of OAC in reducing events, many patients are unable to tolerate OAC due to bleeding risks. Left atrial appendage occlusion (LAAO) devices were developed as implantable technologies to moderate stroke risk in patients with intolerance to OAC. Despite clinical data supporting near-comparable protection against thromboembolic events with OAC, device-related thrombus formation has emerged as a critical complication following LAAO that remains a potential limitation to the safety and efficacy of LAAO. Improved biocompatibility of LAAO devices with fluoropolymers, a well-established stent-coating technology used to reduce thrombus formation and promote endothelialization, may optimize outcomes after LAAO.

The Usefulness of Outpatient Cardiac Telemetry in Patients with Cryptogenic Stroke

Introduction: Atrial fibrillation (AF), apart from non-stenotic supracardiac atherosclerosis and neoplastic disease, is the leading cause of cryptogenic stroke, including embolic stroke of un-determined source (ESUS). The aim of our study was to determine the prevalence of AF in ESUS patients based on 30-day telemetric heart rate monitoring initiated within three months after stroke onset. Another aim was to identify factors that increase the likelihood of detecting subsequent AF among ESUS patients. Material and Methods: patients with first-ever stroke classified as per the ESUS definition were eligible for this study. All patients underwent outpatient 30-day telemetric heart rate monitoring. Results: In the period between 2020 and 2022, 145 patients were included. The mean age of all qualified patients was 54; 40% of eligible patients were female. Six patients (4.14%), mostly male patients (4 vs. 2), were diagnosed with AF within the study period. In each case, the diagnosis related to a patient whose stroke occurred in the course of large vessel occlusion. Episodes of AF were detected between day 1 and 25 after starting ECG monitoring. Out of the analyzed parameters that increase the probability of, A.F.; only supraventricular extrasystoles proved to be an independent factor regarding an increased risk of AF [OR 1.046, CI 95% 1.016-1.071, p-value < 0.01]. Conclusions: The use of telemetry heart rhythm monitoring in an outpatient setting can detect AF in 4% of ESUS patients who have undergone prior diagnostic procedures for cardiogenic embolism. Supraventricular extrasystoles significantly increases the likelihood of AF detection in patients with ESUS within three months following stroke. Comorbid coronary artery disease, diabetes and hypertension, rather than a single-factor clinical burden, increase the likelihood of AF detection in older ESUS patients. ESUS in the course of large vessel occlusion is probably associated with an increased likelihood of cardiogenic embolism.

Thrombectomy in young adults with embolic stroke of undetermined source: Analysis of the Young ESUS study

OBJECTIVES

Embolic Stroke of Undetermined Source (ESUS) is a distinct stroke entity that disproportionately affects young adults. We sought to describe characteristics, workup and outcomes of young adult ESUS patients who underwent thrombectomy, and compare outcomes to those reported in different age groups.

MATERIALS AND METHODS

Young-ESUS is a multicenter longitudinal cohort study that enrolled consecutive patients aged 21-50 years at 41 stroke centers in 13 countries between 2017- 2019. Between-group comparisons were performed using Wilcoxon rank sum test for continuous variables or Fisher's exact test for binary variables. Distribution of functional outcomes after thrombectomy for our young adult cohort versus pediatric and older adult cohorts reported in the literature were described using the Kruskal-Wallis test.

RESULTS

Of 535 patients enrolled in Young-ESUS, 65 (12.1%) were treated with endovascular thrombectomy. Patients who underwent thrombectomy were more likely to undergo in-depth cardiac testing than those who did not, but cardiac abnormalities were not detected more often in this group. Among thrombectomy patients, 35/63 (55.6%) had minimal to no functional disability at follow up. When adjusted for age, stroke severity and IV alteplase, the odds of achieving favorable outcome did not differ between treated versus untreated patients.

CONCLUSIONS

Thrombectomy is not rare in young adults with ESUS. Despite extensive workup, cardiac abnormalities were not more prevalent in the thrombectomy group. More research to determine optimal workup, etiologic factors and favorable outcome of stroke across the lifespan is needed.

Subclinical Atrial Fibrillation: To Anticoagulate or Not?

Atrial fibrillation (AF) carries a stroke risk, often necessitating anticoagulation, especially in patients with risk factors. With the advent of implantable and wearable heart monitors, episodes of short bouts of atrial arrhythmias called atrial high-rate episodes (AHREs) or subclinical AF (SCAF) are commonly identified. The necessity of anticoagulation in patients with SCAF is unclear. However, recent randomized controlled trials, the NOAH-AFNET 6 and ARTESIA, have offered insights into this matter. Furthermore, a study-level meta-analysis combining data from both these trials has provided more detailed information. Reviewing the information thus far, we can conclude that DOACs can result in a notable reduction in the risk of ischemic stroke and can potentially decrease the risk of debilitating stroke, albeit with an increased risk of major bleeding. Thus, informed, shared decision-making is essential, weighing the potential benefits of stroke prevention against the risk of major bleeding when considering anticoagulation in this patient population.

Artificial intelligence-enabled electrocardiogram (AI-ECG) does not predict atrial fibrillation following patent foramen ovale closure

Background

Atrial fibrillation (AF) is a known complication following patent foramen ovale (PFO) closure. AI-enabled ECG (AI-ECG) acquired during normal sinus rhythm has been shown to identify individuals with AF by noting high-risk ECG features invisible to the human eye. We sought to characterize the value of AI-ECG in predicting AF development following PFO closure and investigate key clinical and procedural characteristics possibly associated with post-procedural AF.

Methods

We performed a retrospective analysis of patients who underwent PFO closure at our hospital from January 2011 to December 2022. We recorded the probability (%) of AF using the Mayo Clinic AI-ECG dashboard from pre- and post-procedure ECGs. The cut-off point of ≥ 11 %, which was found to optimally balance sensitivity and specificity in the original derivation paper (the Youden index) was used to label an AI-ECG "positive" for AF. Pre-procedural transesophageal echocardiography (TEE) and pre- and post-procedure transcranial doppler (TCD) data was also recorded.

Results

Out of 93 patients, 49 (53 %) were male, mean age was 55 ± 15 years with mean post-procedure follow up of 29 ± 3 months. Indication for PFO closure in 69 (74 %) patients was for secondary prevention of transient ischemic attack (TIA) and/or stroke. Twenty patients (22 %) developed paroxysmal AF post-procedure, with the majority within the first month post-procedure (15 patients, 75 %). Patients who developed AF were not significantly more likely to have a positive post-procedure AI-ECG than those who did not develop AF (30 % AF vs 27 % no AF, p = 0.8).Based on the PFO-Associated Stroke Causal Likelihood (PASCAL) classification, patients who had PFO closure for secondary prevention of TIA and/or stroke in the "possible" group were significantly more likely to develop AF than patients in "probable" and "unlikely" groups (p = 0.034). AF-developing patients were more likely to have post-procedure implantable loop recorder (ILR) (55 % vs 9.6 %, p < 0.001), and longer duration of ILR monitoring (121 vs 92.5 weeks, p = 0.035). There were no significant differences in TCD and TEE characteristics, device type, or device size between those who developed AF vs those who did not.

Conclusions

In this small, retrospective study, AI-ECG did not accurately distinguish patients who developed AF post-PFO closure from those who did not. Although AI-ECG has emerged as a valuable tool for risk prediction of AF, extrapolation of its performance to procedural settings such as PFO closure requires further investigation.

Percutaneous Patent Foramen Ovale Closure: Stroke and Beyond

Over 750,000 individuals suffer from stroke annually in the United States, with 87% of these strokes being ischemic in nature. Roughly 40% of ischemic strokes occur in individuals 60 years of age or under. A quarter of all ischemic strokes have no identifiable cause despite extensive workup and are deemed cryptogenic in nature. Patent Foramen Ovales (PFO) has been postulated in stroke causation by either paradoxical embolization or platelet activation in the tunnel of the defect. The incidence of PFO is reported to be 15-25% in the general population but rises to 40% in patients with cryptogenic stroke. While the initial trials evaluating PFO closures were non-revealing, subsequent long-term follow-ups, as well as recent trials evaluating PFO closures in cryptogenic stroke patients 60 years of age or under, demonstrated the superiority of percutaneous closure compared to medical therapy alone, leading to FDA approval of PFO closure devices. In this review, we review the diagnosis of PFO, postulated stroke mechanisms, literature supporting PFO closure, patient selection for percutaneous closure, procedural considerations, and associated procedural complications.

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.

Intensive heart rhythm monitoring to decrease ischemic stroke and systemic embolism-the Find-AF 2 study-rationale and design

BACKGROUND

Atrial fibrillation (AF) is one of the most frequent causes of stroke. Several randomized trials have shown that prolonged monitoring increases the detection of AF, but the effect on reducing recurrent cardioembolism, ie, ischemic stroke and systemic embolism, remains unknown. We aim to evaluate whether a risk-adapted, intensified heart rhythm monitoring with consequent guideline conform treatment, which implies initiation of oral anticoagulation (OAC), leads to a reduction of recurrent cardioembolism.

METHODS

Find-AF 2 is a randomized, controlled, open-label parallel multicenter trial with blinded endpoint assessment. 5,200 patients ≥ 60 years of age with symptomatic ischemic stroke within the last 30 days and without known AF will be included at 52 study centers with a specialized stroke unit in Germany. Patients without AF in an additional 24-hour Holter ECG after the qualifying event will be randomized in a 1:1 fashion to either enhanced, prolonged and intensified ECG-monitoring (intervention arm) or standard of care monitoring (control arm). In the intervention arm, patients with a high risk of underlying AF will receive continuous rhythm monitoring using an implantable cardiac monitor (ICM) whereas those without high risk of underlying AF will receive repeated 7-day Holter ECGs. The duration of rhythm monitoring within the control arm is up to the discretion of the participating centers and is allowed for up to 7 days. Patients will be followed for at least 24 months. The primary efficacy endpoint is the time until recurrent ischemic stroke or systemic embolism occur.

CONCLUSIONS

The Find-AF 2 trial aims to demonstrate that enhanced, prolonged and intensified rhythm monitoring results in a more effective prevention of recurrent ischemic stroke and systemic embolism compared to usual care.

Cancer and Atrial Fibrillation Comorbidities Among 25 Million Citizens in Shanghai, China: Medical Insurance Database Study

BACKGROUND

With population aging, the prevalence of both cancer and atrial fibrillation (AF) have increased. However, there is scarce epidemiological data concerning the comorbid state of cancer and AF in low- and middle-income countries, including China.

OBJECTIVE

We aimed to evaluate the site-, sex-, and age-specific profiles of cancer and AF comorbidities in Chinese populations.

METHODS

Data from the Shanghai Municipal Health Commission database between 2015 and 2020 were screened, covering all medical records of Shanghai residents with medical insurance. Site-specific cancer profiles were evaluated for the population with AF relative to the age- and sex-adjusted population of residents without AF. The sex distribution and peak age of cancer diagnosis were also assessed.

RESULTS

A total of 25,964,447 adult patients were screened. Among them, 22,185 patients presented cancers comorbid with AF (median 77, IQR 67-82 years of age; men: n=13,631, 61.44%), while 839,864 presented cancers without AF (median 67, IQR 57-72 years of age; men: n=419,020, 49.89%), thus yielding a higher cancer prevalence among residents with AF (8.27%) than among those without AF (6.05%; P<.001). In the population with AF, the most prevalent cancer type was lung cancer, followed by colorectal, male genital organ, stomach, breast, liver, bladder, thyroid, leukemia, and esophageal cancers. AF was associated with an average of nearly 1.4-fold (prevalence ratio [PR] 1.37, 95% CI 1.35-1.38) increased prevalence of cancer after adjusting for age and sex. For site-specific analyses, an increased prevalence of cancer in the population with AF was observed in 20 of 21 cancer sites. This increased prevalence was most prominent for nonsolid tumors, including multiple myeloma (PR 2.56, 95% CI 2.28-2.87), leukemia (PR 1.73, 95% CI 1.57-1.90), and non-Hodgkin lymphoma (PR 1.59, 95% CI 1.43-1.77); intrathoracic malignancies, including mediastinum (PR 2.34, 95% CI 1.89-2.90), lung (PR 1.64, 95% CI 1.59-1.69), and esophageal cancers (PR 1.41, 95% CI 1.28-1.56); bone and soft tissue neoplasms (PR 1.56, 95% CI 1.37-1.77); and kidney cancer (PR 1.53, 95% CI 1.36-1.72). Cancer prevalence in the population with AF relative to that in the population without AF was higher in men than in women in 14 of 18 cancer sites, and female predominance was only observed for thyroid cancer. The peak age of index cancer diagnosis was lower in the population with AF (age group: 70-74 years) than in that without AF (age group: 75-79 years), especially for specific cancer types, including thyroid, central nervous system, mediastinum, esophageal, bladder, and biliary cancers.

CONCLUSIONS

Patients with AF are associated with increased prevalence, heightened male predominance, and younger peak age of cancer. Further studies are needed to determine whether early screening of specific cancers is cost-effective and beneficial for patients with AF.

Predictors of Atrial Fibrillation in Patients with Embolic Stroke of Unknown Etiology and Implantable Loop Recorders-Further Insights of the TRACK AF Study on the Role of ECG and Echocardiography

Aims-Electrocardiography (ECG) and echocardiographic left atrial (LA) parameters may be helpful to assess the risk of atrial fibrillation (AF) in embolic stroke of unknown etiology (ESUS) and could therefore guide intensity of ECG monitoring. Methods-1153 consecutive patients with ischemic stroke or transient ischemic attack (TIA) were analyzed. An internal loop recorder (ILR) was implanted in 104 consecutive patients with ESUS. Multiple morphologic P-wave parameters in baseline 12-channel ECG and echocardiographic LA parameters were measured and analyzed in patients with and without ILR-detected AF. Using logistic regression, we evaluated the predictive value of several ECG parameters and LA dimensions on the occurrence of AF. Results-In 20 of 104 (19%) patients, AF was diagnosed by ILR during a mean monitoring time of 575 (IQR 470-580) days. Patients with AF were significantly older (72 (67-75) vs. 60 (52-72) years; p = 0.001) and premature atrial contractions (PAC) were more frequently observed (40% vs. 2%; p < 0.001) during baseline ECG. All morphologic P-wave parameters did not show a significant difference between groups. There was a non-significant trend towards a larger LA volume index (31 (24-36) vs. 29 (25-37) mL/m2; p = 0.09) in AF patients. Conclusions-Age and PAC are independently associated with incident AF in ESUS and could be used as markers for selecting patients that may benefit from more extensive rhythm monitoring or ILR implantation. In our consecutive cohort of patients with ESUS, neither morphological P-wave parameters nor LA size were predictive of AF.

Insertable cardiac monitoring results in higher rates of atrial fibrillation diagnosis and oral anticoagulation prescription after ischaemic stroke

AIMS

After an ischaemic stroke, atrial fibrillation (AF) detection allows for improved secondary prevention strategies. This study aimed to compare AF detection and oral anticoagulant (OAC) initiation in patients with an insertable cardiac monitor (ICM) vs. external cardiac monitor (ECM) after ischaemic stroke.

METHODS AND RESULTS

Medicare Fee-for-Service (FFS) insurance claims and Abbott Labs device registration data were used to identify patients hospitalized with an ischaemic stroke in 2017-2019 who received an ICM or ECM within 3 months. Patients with continuous Medicare FFS insurance and prescription drug enrolment in the prior year were included. Patients with prior AF, atrial flutter, cardiac devices, or OAC were excluded. Insertable cardiac monitor and ECM patients were propensity score matched 1:4 on demographics, comorbidities, and stroke hospitalization characteristics. The outcomes of interest were AF detection and OAC initiation evaluated with Kaplan-Meier and Cox proportional hazard regression analyses. A total of 5702 Medicare beneficiaries (ICM, n = 444; ECM, n = 5258) met inclusion criteria. The matched cohort consisted of 2210 Medicare beneficiaries (ICM, n = 442; ECM, n = 1768) with 53% female, mean age 75 years, and mean CHA₂DS₂-VASc score 4.6 (1.6). Insertable cardiac monitor use was associated with a higher probability of AF detection [(hazard ratio (HR) 2.88, 95% confidence interval (CI) (2.31, 3.59)] and OAC initiation [HR 2.91, CI (2.28, 3.72)] compared to patients monitored only with ECM.

CONCLUSION

Patients with an ischaemic stroke monitored with an ICM were almost three times more likely to be diagnosed with AF and to be prescribed OAC compared to patients who received ECM only.

A Bibliometric Analysis of Cardioembolic Stroke From 2012 to 2022

Cardioembolic stroke, a subtype of ischemic stroke with the worst prognosis, is quietly threatening public health. We aimed to visualize the development trend and hotspots of research on cardioembolic stroke. A total of 2886 papers about cardioembolic stroke published from 2012 to 2022 were retrieved in the Web of Science Core Collection (WoSCC) database. Further, we performed a bibliometric analysis of these publications, such as generating cooperation maps, co-citation analysis of journals and references, and cluster analysis of keywords. According to the results, cardioembolic stroke research faces many clinical challenges. We obtained the knowledge maps of countries/institutions, authors, journals with high publications and citations, and representative references in this field. Studies about optimal prevention strategies for cardioembolic stroke, identification of cardioembolism in cryptogenic stroke, and prophylactic anticoagulation for patients with embolic stroke of undetermined source (ESUS) or at high risk of left ventricle (LV) thrombus are in the spotlight.

Establishment and Verification of a Nomogram for Predicting the Probability of New-Onset Atrial Fibrillation After Dual-Chamber Pacemaker Implantation

BACKGROUND

This study aims to establish and validate a nomogram as a predictive model in patients with new-onset atrial fibrillation (AF) after dual-chamber cardiac implantable electronic device (pacemaker) implantation.

METHODS

A total of 1120 Chinese patients with new-onset AF after pacemaker implantation were included in this retrospective study. Patients had AF of at least 180/minute lasting 5 minutes or longer, detected by atrial lead and recorded at least 3 months after implantation. Patients with previous atrial tachyarrhythmias before device implantation were excluded. A total of 276 patients were ultimately enrolled, with 51 patients in the AF group and 225 patients in the non-AF group. Least absolute shrinkage and selection operator (LASSO) method was used to determine the best predictors. Through multivariate logistic regression analysis, a nomogram was drawn as a predictive model. Concordance index, calibration plot, and decision curve analyses were applied to evaluate model discrimination, calibration, and clinical applicability. Internal verification was performed using a bootstrap method.

RESULTS

The LASSO method regression analysis found that variables including peripheral arterial disease, atrial pacing-ventricular pacing of at least 50%, atrial sense-ventricular sense of at least 50%, increased left atrium diameter, and age were important predictors of developing AF. In multivariate logistic regression, peripheral arterial disease, atrial pacing-ventricular pacing of at least 50%, and age were found to be independent predictors of new-onset AF.

CONCLUSION

This nomogram may help physicians identify patients at high risk of new-onset AF after pacemaker implantation at an early stage in a Chinese population.

Heart Disease and Stroke Statistics-2023 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2023 Statistical Update is the product of a full year's worth of effort in 2022 by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. The American Heart Association strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional COVID-19 (coronavirus disease 2019) publications, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Left atrial appendage occlusion

Prevention of stroke represents a goal of primary importance in health systems due to its associated morbidity and mortality. As several patient groups with increased stroke rates have been identified, multiple approaches have been developed and implemented: oral anticoagulation (OAC) for patients with atrial fibrillation, surgical and percutaneous revascularisation in patients with carotid disease, device closure for patients with patent foramen ovale, and now, left atrial appendage occlusion (LAAO) for selected patients with non-valvular atrial fibrillation (NVAF). The latter group of patients are the focus of this review which evaluates the pathophysiology, selection of patients, procedural performance, outcomes of treatment both during and post-procedure, adjunctive therapy, complications, and longer-term outcomes.

Remote Monitoring of Cardiac Implantable Electronic Devices: What is the Evidence?

PURPOSE OF REVIEW

This review offers an overview of the evidence in diagnostic and therapeutic applications of remote monitoring implantable devices.

RECENT FINDINGS

Remote monitoring of cardiac implantable devices has become more and more popular in recent years as healthcare is moving towards a more patient centralized system. For heart failure patients with an ICD or pacemaker, there is controversial evidence regarding improvements in the clinical outcome, e.g., reduction of hospitalization rates or overall mortality. New developments as hemodynamic remote monitoring via measurement of the pulmonary artery pressure are promising technical achievements showing encouraging results. In cardiac remote monitoring of syncope and arrhythmias, implantable loop recorder plays an important role in diagnostic algorithms. Although there is controversial evidence according to remote monitoring of implantable devices, its use is rapidly expanding, giving healthcare providers the opportunity to react promptly to worsening of their patients. Adequate evaluation of the data created by remote monitoring systems remains an unsolved challenge of contemporary healthcare services.

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.

Prediction of atrial fibrillation using a home blood pressure monitor with a high-resolution system

Objective

The usefulness of screening for atrial fibrillation (AF) using several home blood pressure (BP) monitors has been reported. We evaluated the accuracy of a high-resolution system (HiRS) for AF prediction and its usefulness when installed in home BP monitors.

Methods

In patients with paroxysmal, persistent or permanent AF, ECG recording and BP measurements were performed simultaneously. The relationship between ECG rhythm diagnosis and pulse irregularity recognition, using a home BP monitor with HiRS, was investigated. The severity of a pulse disturbance during BP measurement was displayed as an irregular pulse rhythm symbol (IPRS) in three instances. The IPRS was not displayed if the pulse was regular, turned on if there was a weak variation in the pulse, and blinked if there was a strong variation in the pulse.

Results

One hundred and seven patients (44 paroxysmal AF, 63 persistent or permanent AF) were enrolled, and a total of 333 recordings were analysed. The rhythms recorded by each ECG were 73 sinus regular rhythms, 35 extrasystoles, 222 AFs and 3 atrial flutters. Sensitivity and specificity for the prediction of any arrhythmia by the IPRS display of the BP monitor were 95.8% (95% CI 92.6% to 97.6%) and 96.8% (95% CI 92.6% to 100%), respectively. In addition, sensitivity and specificity for the prediction of AF were 100% (95% CI 97.5% to 100%) and 74.8% (95% CI 65.6% to 82.5%), respectively. Sensitivity and specificity for the prediction of AF by the IPRS blinking display were 88.3% (95% CI 83.3% to 92.2%) and 94.6% (95% CI 88.6% to 98.0%%), respectively. IPRS exhibited lighting or blinking during AF occurrence; however, during sinus rhythm, IPRS was not displayed in 72 out of 73 recordings.

Conclusion

The IPRS device predicted AF with precision and may be particularly useful for predicting an arrhythmia attack in patients with paroxysmal AF.

A meta-analysis of extended ECG monitoring in detection of atrial fibrillation in patients with cryptogenic stroke

Objective

The aim of this systematic review is to evaluate the various modalities available for extended ECG monitoring in the detection of atrial fibrillation (AF) following a cryptogenic stroke.

Methods

MEDLINE (Ovid), EMBASE (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL) were searched from January 2011 to November 2021. All randomised controlled trials and prospective cohort studies including the use of extended ECG monitoring >24 hours with a minimum duration of AF of 30 s in patients with either cryptogenic strokes or transient ischaemic attacks were included. A random-effects model was used to pool effect estimates of AF detection rates from different ECG modalities.

Results

3924 studies were identified, of which 47 were included reporting on a pooled population of 6448 patients with cryptogenic stroke. The pooled AF rate for implantable loop recorders (ILRs) increased from 4.9% (3.0%–7.9%) at 1 month to 38.4% (20.4%–60.2%) at 36 months. Mobile cardiac outpatient telemetry (MCOT) had a significantly higher pooled AF detection rate of 12.8% (8.9%–17.9%) versus 4.9% (3.0%–7.9%) for ILR at 1 month (p<0.0001). Predictors for AF detection include duration of monitoring (p<0.0001) and age (p<0.0001) for ILRs, but only age for MCOTs (p<0.020).

Conclusion

MCOT has a higher rate of detection at 1 month and is less invasive. Beyond 1 month, compliance becomes a significant limitation for MCOT. MCOT may be a reasonable alternative AF screening tool for patients with cryptogenic stroke if ILR is not available.

PROSPERO registration number

CRD42022297782.

Multimodal Approach for the Prediction of Atrial Fibrillation Detected After Stroke: SAFAS Study

Background

Intensive screening for atrial fibrillation (AF) has led to a better recognition of this cause in stroke patients. However, it is currently debated whether AF Detected After Stroke (AFDAS) has the same pathophysiology and embolic risk as prior-to-stroke AF. We thus aimed to systematically approach AFDAS using a multimodal approach combining clinical, imaging, biological and electrocardiographic markers.

Methods

Patients without previously known AF admitted to the Dijon University Hospital (France) stroke unit for acute ischemic stroke were prospectively enrolled. The primary endpoint was the presence of AFDAS at 6 months, diagnosed through admission ECG, continuous electrocardiographic monitoring, long-term external Holter during the hospital stay, or implantable cardiac monitor if clinically indicated after discharge.

Results

Of the 240 included patients, 77 (32%) developed AFDAS. Compared with sinus rhythm patients, those developing AFDAS were older, more often women and less often active smokers. AFDAS patients had higher blood levels of NT-proBNP, osteoprotegerin, galectin-3, GDF-15 and ST2, as well as increased left atrial indexed volume and lower left ventricular ejection fraction. After multivariable analysis, galectin-3 ≧ 9 ng/ml [OR 3.10; 95% CI (1.03–9.254), p = 0.042], NT-proBNP ≧ 290 pg/ml [OR 3.950; 95% CI (1.754–8.892, p = 0.001], OPG ≥ 887 pg/ml [OR 2.338; 95% CI (1.015–5.620), p = 0.046) and LAVI ≥ 33.5 ml/m2 [OR 2.982; 95% CI (1.342–6.625), p = 0.007] were independently associated with AFDAS.

Conclusion

A multimodal approach combining imaging, electrocardiography and original biological markers resulted in good predictive models for AFDAS. These results also suggest that AFDAS is probably related to an underlying atrial cardiopathy.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT03570060].

Left atrial morpho-functional remodeling in atrial fibrillation assessed by three dimensional speckle tracking echocardiography and its value in atrial fibrillation screening

BACKGROUND

Three dimensional speckle tracking echocardiography (3D STE) is a novel technique combining 3D echocardiography and speckle tracking analysis. 3D STE software dedicated to the left atrium (LA) was recently available. Our study aimed to assess (1) atrial fibrillation (AF) related LA morpho-functional remodeling using 3D STE and (2) value of LA function parameters in identifying paroxysmal AF (PAF).

METHODS

One hundred thirty-nine PAF, 109 persistent AF (Per-AF) and 59 non-AF subjects underwent 3D STE. LA phasic volumes and total LA emptying fraction (LAEF) were obtained and used to calculate passive (pLAEF) and active LA emptying fraction (aLAEF) based on atrial contraction. LA longitudinal and circumferential strain representing reservoir (LASr/LASrc), conduit (LAScd/LAScdc) and pump (LASct/LASctc) function were also assessed.

RESULTS

3D STE was found to have good reproducibility. Increase of LA volumes and decrease of parameters representing LA reservoir and pump function were independently associated with AF as well as AF burden. The correlations between LA emptying fraction and LA circumferential strain representing the same function were always stronger than those with LA longitudinal strain (p < 0.001). Minimal LA volume, LAEF, aLAEF, LASrc and LASctc can be used to accurately differentiate PAF from non-AF subjects (AUC > 0.8) with great sensitivity and specificity.

CONCLUSIONS

Assessing LA remodeling in AF using 3D STE was feasible. AF and AF burden were independently associated with LA enlargement and impairment of reservoir and pump function but not conduit function. LA function parameters can indicate underlying PAF and thus can guide AF screening strategy.

The Added Value of Atrial Strain Assessment in Clinical Practice

Speckle tracking echocardiography has emerged as a sensitive tool to analyze myocardial function with improved diagnostic accuracy and prognostic value. Left atrial strain assessment has become a novel imaging method in cardiology with superior prognostic value compared to conventional left atrial volume indices. Left atrial function is divided into three phases, reservoir function being the most important. This review summarizes the added value of speckle tracking echocardiography derived left atrial strain assessment in clinical practice. Recently published data suggest the prognostic value of left atrial reservoir function in heart failure, atrial fibrillation, stroke and valvular heart disease. Furthermore, left atrial reservoir strain proved to be a predictor of cardiovascular morbidity and mortality in the general population. Thus, routine assessment of left atrial function can be an optimal strategy to improve cardiovascular risk prediction and supplement the current risk prediction models.

Clinical Implications of Atrial Fibrillation Detection Using Wearable Devices in Patients With Cryptogenic Stroke (CANDLE-AF) Trial: Design and Rationale

Background

Although many electrocardiography wearable devices have been released recently for the detection of atrial fibrillation (AF), there are few studies reporting prospective data for wearable devices compared to the strategy of the existing guidelines in the detection of atrial fibrillation (AF) after cryptogenic stroke. A tiny single-patch monitor is more convenient than a conventional Holter monitor recording device and, therefore, longer duration of monitoring may be acceptable.

Methods and Design

The CANDLE-AF study is a multicenter, prospective, randomized controlled trial. Patients with transient ischemic attack or ischemic stroke without any history of AF will be enrolled. The superiority of the 72-h single-patch monitor to standard strategy and non-inferiority of the 72-h single-patch monitor to an event-recorder-type device will be investigated. Single-patch monitor arm will repeat monitoring at 1, 3, 6, and 12 months, event-recorder-type arm will repeat monitoring twice daily for 12 months. The enrollment goal is a total of 600 patients, and the primary outcome is the detection of AF which continues at least 30 s during study period. The secondary outcome is the rate of changes from antiplatelet to anticoagulant and major adverse cardiac and cerebrovascular events within 1 year.

Conclusions

The results of CANDLE-AF will clarify the role of a single-lead patch ECG for the early detection of AF in patients with acute ischemic stroke. In addition, the secondary outcome will be analyzed to determine whether more sensitive AF detection can affect the prognosis and if further device development is meaningful. (cris.nih.go.kr KCT0005592).

Impact of recording length and other arrhythmias on atrial fibrillation detection from wrist photoplethysmogram using smartwatches

This study aimed to evaluate whether quantitative analysis of wrist photoplethysmography (PPG) could detect atrial fibrillation (AF). Continuous electrocardiograms recorded using an electrophysiology recording system and PPG obtained using a wrist-worn smartwatch were simultaneously collected from patients undergoing catheter ablation or electrical cardioversion. PPG features were extracted from 10, 25, 40, and 80 heartbeats of the split segments. Machine learning with a support vector machine and random forest approach were used to detect AF. A total of 116 patients were evaluated. We annotated > 117 h of PPG. A total of 6475 and 3957 segments of 25-beat pulse-to-pulse intervals (PPIs) were annotated as AF and sinus rhythm, respectively. The accuracy of the 25 PPIs yielded a test area under the receiver operating characteristic curve (AUC) of 0.9676, which was significantly better than the AUC for the 10 PPIs (0.9453; P < .001). PPGs obtained from another 38 patients with frequent premature ventricular/atrial complexes (PVCs/PACs) were used to evaluate the impact of other arrhythmias on diagnostic accuracy. The new AF detection algorithm achieved an AUC of 0.9680. The appropriate data length of PPG for optimizing the PPG analytics program was 25 heartbeats. Algorithm modification using a machine learning approach shows robustness to PVCs/PACs.

Commercially Available Heart Rate Monitor Repurposed for Automatic Arrhythmia Detection with Snapshot Electrocardiographic Capability: A Pilot Validation

The usefulness of opportunistic arrhythmia screening strategies, using an electrocardiogram (ECG) or other methods for random “snapshot” assessments is limited by the unexpected and occasional nature of arrhythmias, leading to a high rate of missed diagnosis. We have previously validated a cardiac monitoring system for AF detection pairing simple consumer-grade Bluetooth low-energy (BLE) heart rate (HR) sensors with a smartphone application (RITMIA™, Heart Sentinel srl, Italy). In the current study, we test a significant upgrade to the above-mentioned system, thanks to the technical capability of new HR sensors to run algorithms on the sensor itself and to acquire, and store on-board, single-lead ECG strips. We have reprogrammed an HR monitor intended for sports use (Movensense HR+) to run our proprietary RITMIA algorithm code in real-time, based on RR analysis, so that if any type of arrhythmia is detected, it triggers a brief retrospective recording of a single-lead ECG, providing tracings of the specific arrhythmia for later consultation. We report the initial data on the behavior, feasibility, and high diagnostic accuracy of this ultra-low weight customized device for standalone automatic arrhythmia detection and ECG recording, when several types of arrhythmias were simulated under different baseline conditions. Conclusions: The customized device was capable of detecting all types of simulated arrhythmias and correctly triggered a visually interpretable ECG tracing. Future human studies are needed to address real-life accuracy of this device.

Recurrent Stroke Incidence and Etiology in Patients with Embolic Stroke of Undetermined Source and Other Stroke Subtypes

AIMS

This study aimed at clarifying the incidence of recurrent stroke and its etiology in patients with embolic stroke of undetermined source (ESUS) and other stroke subtypes in both the acute and chronic periods.

METHODS

A total of 645 patients who were admitted with acute ischemic stroke (IS) between March 2015 and August 2019 were enrolled. Among them, 511 patients with ESUS, cardioembolism (CE), large artery atherosclerosis (LAA), or small vessel disease (SVD) were analyzed in this study. After discharge, 391 patients who visited the outpatient clinic were followed up until August 2020. The outcome was stroke recurrence.

RESULTS

In the acute admission, recurrence rates were 7.6%, 8.1%, 18.8%, and 2.2% in patients with ESUS, CE, LAA, and SVD, respectively, and there were significant differences between the groups. The subtype of recurrence was almost identical to that of the index stroke. In the outpatient clinic, the annual recurrence rates were 4.4%, 4.3%, 6.0%, and 2.9% in ESUS, CE, LAA, and SVD, respectively, and no difference was observed. Subtypes of recurrence in outpatients with ESUS included ESUS, intracerebral hemorrhage (ICH), and SVD. Patients with ESUS and SVD had a higher risk of ICH during follow-up.

CONCLUSIONS

Although the risk of recurrence was comparable between patients with ESUS and CE and intermediate between patients with LAA and SVD, in the acute admission unit, the risk in outpatients was similar among all subtypes. ESUS was the most recurrent stroke subtype in outpatients with ESUS. The risk of hemorrhagic stroke was significant in patients with SVD and ESUS.

Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2022 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population and an enhanced focus on social determinants of health, adverse pregnancy outcomes, vascular contributions to brain health, and the global burden of cardiovascular disease and healthy life expectancy.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Longitudinal Outcomes in Cryptogenic Stroke Patients With and Without Long-term Cardiac Monitoring for Atrial Fibrillation

Background

Guidelines recommend a confirmed diagnosis of atrial fibrillation (AF) to initiate oral anticoagulation in cryptogenic stroke (CS) patients. However, the intermittent nature of AF can make detection challenging with intermittent short-term cardiac monitoring.

Objective

The purpose of this retrospective cohort study was to examine post-CS utilization of cardiac monitoring and associated clinical outcomes.

Methods

Adults with incident hospitalization for CS were identified in the Optum® claims database and assessed for cardiac monitoring received poststroke. Patient were stratified into those with a long-term insertable cardiac monitor (ICM) vs external cardiac monitor (ECM) only. The timing of ICM placement poststroke was treated as a time-dependent covariate. The clinical outcomes of interest were time to AF diagnosis, oral anticoagulation usage, and all-cause mortality.

Results

A total of 12,994 patients met selection criteria for the analysis, of whom 1949 (15%) received an ICM and 11,045 (85%) received ECM only. In those who had received an ECM as their first monitoring modality, only 4.4% moved on to receive an ICM for longer-term monitoring. Use of ECM before ICM was associated with a longer time to AF diagnosis (median 336 vs 194 days). Compared to those with ECM only, ICM patients had a significantly lower rate of death (hazard ratio [HR] 0.70; P = .004), and faster time to AF diagnosis (HR 1.50; P <.0001) and anticoagulation initiation (HR 1.57; P <.0001) during follow-up of up to 5 years after CS.

Conclusion

In a real-world study of CS patients, prolonged cardiac monitoring was associated with higher rates of AF detection and treatment, and higher odds of survival.

Comparison of Different Dosages of Alteplase in Atrial Fibrillation-Related Acute Ischemic Stroke After Intravenous Thrombolysis: A Nationwide, Multicenter, Prospective Cohort Study in Taiwan

Background

Insufficient evidence is available for patients with acute ischemic stroke with atrial fibrillation (AF) to determine the efficacy and safety of different dosages of intravenous thrombolysis treatment. This study examined clinical outcomes in Chinese patients with stroke with and without AF after intravenous thrombolysis treatment with different intravenous thrombolysis doses.

Methods and Results

This multicenter, prospective cohort study recruited 2351 patients with acute ischemic stroke (1371 with AF and 980 without AF) treated with intravenous thrombolysis using alteplase. The Totaled Health Risks in Vascular Events score is a validated risk‐scoring tool used for assessing patients with acute ischemic stroke with and without AF. We evaluated favorable functional outcome at day 90 and symptomatic intracranial hemorrhage within 24 to 36 hours and outcomes of the patients receiving different doses of alteplase. Compared with the non‐AF group, the AF group exhibited a 2‐ to 3‐fold increased risk of symptomatic intracranial hemorrhage according to the National Institute of Neurological Disorders and Stroke standard (relative risk [RR], 2.10 [95% CI, 1.35–3.26]). Favorable functional outcome at 90 days and symptomatic intracranial hemorrhage rates according to the European Cooperative Acute Stroke Study II and the Safe Implementation of Thrombolysis in Stroke‐Monitoring Study standards did not significantly differ between the AF and non‐AF groups. In addition, the low‐dose alteplase subgroup exhibited an increased risk of symptomatic intracranial hemorrhage according to the National Institute of Neurological Disorders and Stroke standard (RR, 2.84 [95% CI, 1.63–4.96]). A validation study confirmed these findings after adjustment for scores determined using different stroke risk‐scoring tools.

Conclusions

Different alteplase dosages did not affect functional status at 90 days in the AF and non‐AF groups. Thus, the adoption of low‐dose alteplase simply because of AF is not recommended.

Subcutaneouscardiac Rhythm Monitors: A Comprehensive Review

Subcutaneous loop recorders (SCRMs) are subcutaneous electronic devices which have revolutionized the field of arrhythmia detection. They have become increasingly appealing due to advances such as miniaturization of device, longer battery life, bluetooth capabilities and relatively simple implantation technique without the need for complex surgical suites. They can be implanted in the office, patient bedside without the need to go to the operating room. One of the most common indications for their implantation is detection of atrial fibrillation (AF) after a cryptogenic stroke. They have also been utilized for assessing the success of rhythm control strategies such post pulmonary venous isolation. More recently studies have assessed the utility of SCRMs for detecting silent AF in at risk populations such as patients with sleep apnea or those on hemodialysis. In this paper, we review the evolution of SCRMs, the clinical studies assessing their value for different indications, their role incurrent clinical practice and future avenues in the era of smart wearable devices like apple watch etc.

Detection of subclinical atrial fibrillation after cryptogenic stroke using implantable cardiac monitors

BACKGROUND

Implantable cardiac monitor (ICM) revealed subclinical atrial fibrillation (SCAF) in up to 30% of cryptogenic stroke (CS) patients in randomized trials. However, real world data are limited.

OBJECTIVES

We investigated SCAF occurrence, treatments, clinical outcomes and predictors of SCAF in a multicenter real-world population subjected to ICM after CS.

METHODS

From September 2016 to November 2019, 20 Italian centers collected data of consecutive patients receiving ICM after CS and followed with remote and outpatient follow-up according to clinical practice. All device-detected AF events were confirmed by the cardiologist to diagnose SCAF.

RESULTS

ICM was implanted in 334 CS patients (mean age±SD 67.4±11.5 years, 129 (38.6%) females, 242 (76.1%) with CHA₂DS₂-VASC score≥4). During a follow-up of 23.6 (IQR 14.6-31.5) months, SCAF was diagnosed in 92 (27.5%) patients. First episode was asymptomatic in 81 (88.1%). SCAF daily burden ≥5 minutes was 22.0%, 24.1% and 31.5% at 6, 12, and 24 months after ICM implantation. Median time to first day with AF was 60 (IQR 18-140) days. Female gender, age>69 years, PR interval>160 ms and cortical-subcortical infarct type at enrolment were independently associated with an increased risk of SCAF.

CONCLUSIONS

In a real-world population, ICM detected SCAF in more than a quarter of CS patients. This experience confirms the relevance of implanting CS patients, for maximizing the possibilities to detect AF, following failure of Holter monitoring, according to guidelines. However, there is need to demonstrate that shift to oral anticoagulation following SCAF detection is associated with reduced risk of recurrent stroke.

Enhanced detection of abnormalities in heart rate variability and dynamics by 7-day continuous ECG monitoring

Background

The analysis of heart rate variability (HRV) and heart rate (HR) dynamics by Holter ECG has been standardized to 24 hs, but longer‐term continuous ECG monitoring has become available in clinical practice. We investigated the effects of long‐term ECG on the assessment of HRV and HR dynamics.

Methods

Intraweek variations in HRV and HR dynamics were analyzed in 107 outpatients with sinus rhythm. ECG was recorded continuously for 7 days with a flexible, codeless, waterproof sensor attached on the upper chest wall. Data were divided into seven 24‐h segments, and standard time‐ and frequency‐domain HRV and nonlinear HR dynamics indices were computed for each segment.

Results

The intraweek coefficients of variance of HRV and HR dynamics indices ranged from 2.9% to 26.0% and were smaller for frequency‐domain than for time‐domain indices, and for indices reflecting slower HR fluctuations than faster fluctuations. The indices with large variance often showed transient abnormalities from day to day over 7 days, reducing the positive predictive accuracy of the 24‐h ECG for detecting persistent abnormalities over 7 days. Conversely, 7‐day ECG provided 2.3‐ to 6.5‐fold increase in sensitivity to detect persistent plus transient abnormalities compared with 24‐h ECG. It detected an average of 1.74 to 2.91 times as many abnormal indices as 24‐h ECG.

Conclusions

Long‐term ECG monitoring increases the accuracy and sensitivity of detecting persistent and transient abnormalities in HRV and HR dynamics and allows discrimination between the two types of abnormalities. Whether this discrimination improves risk stratification deserves further studies.

Left Atrium Assessment by Speckle Tracking Echocardiography in Cryptogenic Stroke: Seeking Silent Atrial Fibrillation

Silent atrial fibrillation (AF) may be the cause of some cryptogenic strokes (CrS). The aim of the study was to analyse atrial size and function by speckle tracking echocardiography in CrS patients to detect atrial disease. Patients admitted to the hospital due to CrS were included prospectively. Echocardiogram analysis included left atrial ejection fraction (LAEF) and atrial strain. Insertable cardiac monitor was implanted, and AF was defined as an episode of ≥1 min in the first year after stroke. Left atrial enlargement was defined as indexed volume > 34 mL/m². Seventy-five consecutive patients were included, aged 76 ± 9 years (arterial hypertension 75%). AF was diagnosed in 49% of cases. The AF group had higher atrial volume and worse atrial function: peak atrial longitudinal strain (PALs) 19.6 ± 5.7% vs. 29.5 ± 7.2%, peak atrial contraction strain (PACs) 8.9 ± 3.9% vs. 16.5 ± 6%, LAEF 46.8 ± 11.5% vs. 60.6 ± 5.2%; p < 0.001. AF was diagnosed in 20 of 53 patients with non-enlarged atrium, and in 18 of them, atrial dysfunction was present. The multivariate logistic regression analysis demonstrated an independent association between detection of AF and atrial volume, LAEF, and strain. Cut-off values were obtained: LAEF < 55%, PALs < 21.4%, and PACs < 12.9%. In conclusion, speckle tracking echocardiography in CrS patients improves silent atrial disease diagnosis, with or without atrial enlargement.

Implantable Loop Recorders-Syncope, Cryptogenic Stroke, Atrial Fibrillation

The implantable loop recorder (ILR) is a subcutaneous, single-lead, electrocardiographic (ECG) monitoring device used for diagnosis in patients with recurrent, unexplained episodes of palpitations or syncope, for long-term monitoring in patients at risk for atrial fibrillation (AF), and to guide clinical management in patients with known AF. These devices are capable of storing and transmitting ECG data automatically in response to a significant bradyarrhythmia or tachyarrhythmia or in response to patient activation. This document aims to review the clinical utility of ILRs for arrhythmia monitoring in common clinical situations such as syncope, cryptogenic stroke, and management of patients with known AF.

Reexamination of the Embolic Stroke of Undetermined Source Concept

Occult atrial fibrillation (AF) is a leading cause of stroke of unclear cause. The optimal approach to secondary stroke prevention for these patients remains elusive. The term embolic stroke of undetermined source (ESUS) was coined to describe ischemic strokes in which the radiographic features demonstrate territorial infarcts resembling those seen in patients with confirmed sources of embolism but without a clear source of embolism detected. It was assumed that patients with ESUS had a high rate of occult AF and would benefit from treatment with direct oral anticoagulants, which are at least as effective as vitamin K antagonists for secondary stroke prevention in patients with AF, but with a much lower risk of intracerebral hemorrhage. Two recent large randomized trials failed to show superiority of direct oral anticoagulants over aspirin in ESUS patients. These findings prompt a reexamination of the ESUS concept, with the goal of improving specificity for detecting patients with a cardioembolic cause. Based on the negative trial results, there is renewed interest in the role of long-term cardiac monitoring for AF in patients who fit the current ESUS definition, as well as the clinical implication of detecting AF. Ongoing trials are exploring these questions. Current ESUS definitions do not accurately detect the patients who should be prescribed direct oral anticoagulants, potentially because occult AF is less common than expected in these patients and/or anticoagulants may be less beneficial in patients with ESUS but no AF than they are for patients with stroke with established AF. More specific criteria to identify patients who may be at higher risk for occult AF and reduce their risk of subsequent stroke have been developed and are being tested in ongoing clinical trials.

Computational modeling identifies embolic stroke of undetermined source patients with potential arrhythmic substrate

Cardiac magnetic resonance imaging (MRI) has revealed fibrosis in embolic stroke of undetermined source (ESUS) patients comparable to levels seen in atrial fibrillation (AFib). We used computational modeling to understand the absence of arrhythmia in ESUS despite the presence of putatively pro-arrhythmic fibrosis. MRI-based atrial models were reconstructed for 45 ESUS and 45 AFib patients. The fibrotic substrate's arrhythmogenic capacity in each patient was assessed computationally. Reentrant drivers were induced in 24/45 (53%) ESUS and 22/45 (49%) AFib models. Inducible models had more fibrosis (16.7 ± 5.45%) than non-inducible models (11.07 ± 3.61%; p<0.0001); however, inducible subsets of ESUS and AFib models had similar fibrosis levels (p=0.90), meaning that the intrinsic pro-arrhythmic substrate properties of fibrosis in ESUS and AFib are indistinguishable. This suggests that some ESUS patients have latent pre-clinical fibrotic substrate that could be a future source of arrhythmogenicity. Thus, our work prompts the hypothesis that ESUS patients with fibrotic atria are spared from AFib due to an absence of arrhythmia triggers.

Validation of Adhesive Single-Lead ECG Device Compared with Holter Monitoring among Non-Atrial Fibrillation Patients

There are few reports on head-to-head comparisons of electrocardiogram (ECG) monitoring between adhesive single-lead and Holter devices for arrhythmias other than atrial fibrillation (AF). This study aimed to compare 24 h ECG monitoring between the two devices in patients with general arrhythmia. Twenty-nine non-AF patients with a workup of pre-diagnosed arrhythmias or suspicious arrhythmic episodes were evaluated. Each participant wore both devices simultaneously, and the cardiac rhythm was monitored for 24 h. Selective ECG parameters were compared between the two devices. Two cardiologists independently compared the diagnoses of each device. The two most frequent monitoring indications were workup of premature atrial contractions (41.4%) and suspicious arrhythmia-related symptoms (37.9%). The single-lead device had a higher noise burden than the Holter device (0.04 ± 0.05% vs. 0.01 ± 0.01%, p = 0.024). The number of total QRS complexes, ventricular ectopic beats, and supraventricular ectopic beats showed an excellent degree of agreement between the two devices (intraclass correlation coefficients = 0.991, 1.000, and 0.987, respectively). In addition, the minimum/average/maximum heart rates showed an excellent degree of agreement. The two cardiologists made coherent diagnoses for all 29 participants using both monitoring methods. In conclusion, the single-lead adhesive device could be an acceptable alternative for ambulatory ECG monitoring in patients with general arrhythmia.

Left Atrial Diameter and Atrial Ectopic Burden in Patients with Embolic Stroke of Undetermined Source: Risk Stratification of Atrial Fibrillation with Insertable Cardiac Monitor Analysis

Background and Purpose

An insertable cardiac monitor (ICM) has been demonstrated to be a useful tool for detecting subclinical atrial fibrillation (AF) in patients with embolic stroke of undetermined source (ESUS). This study aimed to identify the clinical predictors of AF in ESUS patients with ICMs.

Methods

We retrospectively selected consecutive patients with an ICM implanted for AF detection following ESUS. The primary endpoint was defined as any AF episode lasting for longer than 5 min. The atrial ectopic burden (AEB) was calculated as the percentage of the number of conducted QRS from atrial ectopy on Holter monitoring.

Results

This study included 136 patients. AF lasting ≥5 min was detected in 20 patients (14.7%) during a median follow-up period of 6.6 months (interquartile range, 3.3–10.8 months). AF patients had a higher AEB (0.20% vs. 0.02%, p<0.001) and a larger left atrial diameter (LAD, 41.0 mm vs. 35.3 mm, p<0.001) than those without AF. The areas under the receiver operating characteristic curves were 0.795 and 0.816 for the LAD and log-transformed AEB, respectively, for the best cutoff values of 38.5 mm for LAD and 0.050% for AEB. AF lasting ≥5 min was detected in 34.6% (9/26) of patients with LAD ≥38.5 mm and AEB ≥0.050%, and in 0% (0/65) of those with LAD <38.5 mm and AEB <0.050%.

Conclusions

AF was detected in a significant proportion of ESUS patients during a 6.6-month follow-up. The LAD and AEB are good predictors of AF and might be useful for AF risk stratification in ESUS patients.

Cardiac events monitoring

Cardiac events recorders have been developed in order to record the heart rhythm during symptoms such as palpitations or presyncope, to first make a diagnosis, and subsequently drive the treatment strategy. In other circumstances, they can be also used in asymptomatic patients (to record silent atrial fibrillation for instance). Because they are non-invasive, potentially cost-saving and relatively easy to use, the external rhythm recording devices have shown some great advances in the last years, spreading from photoplethysmographic technique to real ECG reconstruction. Technological advances in the field of microelectronics, as well as in the field of data transmission have contributed to their widespread use in cardiology. The trend for miniaturization was also expanded to the implantable recorders. This paper will review will review advantages and limitations of the different existing available well-established recording devices, as well as the last technological developments in terms of ECG recordings.