Detecting Atrial Fibrillation in Patients With an Embolic Stroke of Undetermined Source (from the DAF-ESUS registry)

Incidence of atrial fibrillation in patients with renal infarction: A retrospective cohort analysis of the Korean national health insurance registry

BACKGROUND

Regarding the pathophysiology of renal infarction (RI), cardioembolic causes could have large proportion. However, there are notable variations in prevalence of atrial fibrillation (AF) among patients with RI across different studies, ranging from 17 to 65%. The primary objective of this study is to analyze the incidence of AF in patients with RI.

METHODS

This nationwide retrospective cohort study enrolled 5200 patients with RI from the Korean National Institute of Health Services database spanning the years 2013 to 2019. The study accessed the AF incidence rate within 12 months in patients without a prior history of AF. Events occurring within 3 months of RI diagnosis were excluded to mitigate cases diagnosed during the initial screening or those with AF diagnoses that were potentially overlooked in the past.

RESULTS

AF occurred in 19.1% of patients with RI over the entire period (median: 2.5 years, interquartile range 1.04-4.25 years). The majority of AF cases (16.1%) occured within the first year, resulting in an overall incidence rate of 7.0 per 100 person-years. Patients with newly developed AF were, on average, older than those who did not develop AF (64.1 vs. 57.3 years, P < 0.001). The independent predictors of AF were identified as age, male sex, higher body mass index, current smoking, ischemic heart disease, and heart failure.

CONCLUSIONS

Physicians should consider the implementation of active rhythm monitoring for patients with RI to identify potential occurrence of subclinical AF, even if not initially diagnosed during the initial screening after RI diagnosis.

Experience and insights from a prolonged electrocardiographic monitorization with a wearable system after an embolic stroke of unknown source

BACKGROUND

Embolic cerebrovascular events that remain of unknown etiology after a thorough diagnostic evaluation, are known as Embolic Strokes of Undetermined Source (ESUS). Subclinical atrial fibrillation (AF) represents a significant underlying cause of ESUS. Our aims were to examine the overall diagnostic yield of a prolonged cardiac monitoring wearable system (PCMw) after an ESUS to detect AF and factors associated with it, including the time frame from the ESUS event to PCMw initiation. Additionally, to evaluate the frequency of unexpected arrhythmic events (UAE) and their prognostic implications.

METHODS

We retrospectively analyzed 200 ECG recordings (3-leads, 30 days duration) by means of a PCMw in patients with an ESUS to detect AF lasting longer than 30 s, between 2017 and 2021. UAE were defined as arrhythmia events that were not correlated to the main reason of prolonged cardiac monitoring.

RESULTS

AF was detected in 21 patients (10.5%). Patients with AF had more left atrial enlargement (OR = 4.22 [1.59-6.85]; p = .01) and atrial arrythmias in the initial 24-h Holter during hospitalization (OR = 5.73 [2.03-16.49]; p = .001). The detection of AF was significatively higher if the PCMw was worn within the first 30 days after the ESUS compared to beyond 30 days (17% vs. 10.3%; p = .002). Fifty three patients (26.5%) had UAE during PCMw. In six of them these findings led to targeted treatment.

CONCLUSION

PCMw represents a feasible non-invasive device that could reliably detect subclinical AF episodes after an ESUS. Diagnostic yield was significatively higher when used within the first 30 days after the event, especially in selected patients. UAE were common, but did not impact prognosis.

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.

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.

Review and update of the concept of embolic stroke of undetermined source

Ischaemic strokes have traditionally been classified according to the TOAST criteria, in which strokes with unclear aetiology are classified as cryptogenic strokes. However, the definition of cryptogenic stroke did not meet the operational criteria necessary to define patient populations for randomized treatment trials. To address this problem, the concept of embolic stroke of undetermined source (ESUS) was developed and published in 2014. A hypothesis that underpinned this concept was that most strokes in patients with ESUS are caused by embolic events, perhaps many cardioembolic, and that anticoagulation would prevent secondary ischaemic events. On this basis, two large randomized trials were conducted to compare the non-vitamin K antagonist oral anticoagulants (NOACs) dabigatran and rivaroxaban with aspirin. Neither NOAC was superior to aspirin in these trials, although subgroups of patients with ESUS seemed to benefit specifically from anticoagulation or antiplatelet therapy. The neutral results of the trials of anticoagulation and insights into ESUS from research conducted since the concept was introduced warrant reassessment of the ESUS construct as a research concept and a treatment target. In this Review, we discuss the evidence produced since the concept of ESUS was introduced, and propose updates to the criteria and diagnostic algorithm in light of the latest knowledge.

European Stroke Organisation (ESO) guideline on screening for subclinical atrial fibrillation after stroke or transient ischaemic attack of undetermined origin

We aimed to provide practical recommendations for the screening of subclinical atrial fibrillation (AF) in patients with ischaemic stroke or transient ischaemic attack (TIA) of undetermined origin. These guidelines are based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. Five relevant Population, Intervention, Comparator, Outcome questions were defined by a multidisciplinary module working group (MWG).

Longer duration of cardiac rhythm monitoring increases the detection of subclinical AF, but the optimal monitoring length is yet to be defined. We advise longer monitoring to increase the rate of anticoagulation, but whether longer monitoring improves clinical outcomes needs to be addressed. AF detection does not differ from in- or out-patient ECG-monitoring with similar monitoring duration, so we consider it reasonable to initiate in-hospital monitoring as soon as possible and continue with outpatient monitoring for more than 48h. Although insertable loop recorders (ILR) increase AF detection based on their longer monitoring duration, comparison with non-implantable ECG devices for similar monitoring time is lacking. We suggest the use of implantable devices, if feasible, for AF detection instead of non- implantable devices to increase the detection of subclinical AF. There is weak evidence of a useful role for blood, ECG, and brain imaging biomarkers for the identification of patients at high risk of AF. In patients with patent foramen ovale, we found insufficient evidence from RCT, but prolonged cardiac monitoring in patients >55 years is advisable for subclinical AF detection. To conclude, in adult patients with ischaemic stroke or TIA of undetermined origin, we recommend longer duration of cardiac rhythm monitoring of more than 48h and if feasible with IRL to increase the detection of subclinical AF.

Association between CHARGE-AF risk score and LA mechanics: LA reservoir strain can be a single parameter for predicting AF risk

AIMS

Atrial fibrillation (AF) is a prevalent arrhythmia and the leading preventable cause of cardioembolic stroke. Scoring systems for predicting AF risk do not use imaging modalities. We sought to determine whether LA longitudinal strain could be used as a single parameter for predicting the risk of AF.

METHODS AND RESULTS

Consecutive patients diagnosed with diastolic dysfunction between December 2019 and March 2020 were included. Two-dimensional, colour flow, continuous pulse-wave, and tissue Doppler transthoracic echocardiography (TTE) were performed using a Vivid E9 imaging system (GE Medical Systems, Chicago, USA). Measurements were obtained in the standard manner recommended by the American Society of Echocardiography. Moreover, LA longitudinal strain was measured using 2D speckle tracking echocardiography in the four-chamber view to evaluate left atrial function. The CHARGE-AF scoring system was used to predict AF risk.A total of 148 patients (mean age: 57.6 ± 11.9; male: 53%) with feasible views for LA strain measurement were divided into two groups based on a 10% CHARGE-AF cut-off score. The >10% group (48 patients; 32%) was defined as having a predicted 5-year AF risk >10%, and the ≤10% group (100 patients; 68%) was defined as having a predicted risk <10%. In the multivariate analysis, LA reservoir strain (LASr) was independently associated with CHARGE-AF score. Furthermore, using the Pearson correlation method, LASr was found to be highly correlated with CHARGE-AF score (r = -0.74, p < 0.0001).

CONCLUSIONS

LASr was highly correlated with CHARGE-AF risk score and may be used as a parameter to predict atrial myopathy and hence AF risk.

Difficult issues in the management of patients with atrial fibrillation: a neurologist's point of view

The article evaluates recent perspectives about the role of oral anticoagulants in the secondary prevention of cardioembolic stroke. The timing of prescribing drugs for ischemic stroke and transient ischemic attack is discussed in accordance with current clinical guidelines and the results of clinical trials. The issues of prescribing oral anticoagulants in some problematic situations, such as the elderly and senile age, reperfusion therapy, presence of hemorrhagic transformation, combined atherosclerosis of major head and neck arteries, cerebral microangiopathy, history of intracerebral hemorrhage, cryptogenic stroke, and low patient compliance are considered. Finally, an anticoagulant therapy algorithm in the acute period of cardioembolic stroke is presented.

Left Ventricular Diastolic Dysfunction as Predictor of Unfavorable Prognosis After ESUS

Objective

Identification of echocardiographic, hemodynamic and biochemical predictors of unfavorable prognosis after embolic strokes of undetermined etiology (ESUS) in patients at age <65.

Patients and Methods

Out of 520 ischemic stroke patients we selected 64 diagnosed with ESUS and additional 36 without stroke but with similar risk profile. All patients underwent echocardiography, non-invasive assessment of hemodynamic parameters using SphygmoCor tonometer and measurements of selected biomarkers. Follow-up time was 12 months.

Results

Nine percent of patients died, and recurrent ischemic stroke occurred in 9% of patients only in the ESUS group. Atrial fibrillation (AF) occurred in 10% of patients and the ESUS group had a significantly poorer outcome of AF in the first 2 months after hospitalization. The outcome of re-hospitalization was 28% in the ESUS group and 17% in the control group. In the multivariate analysis mean early diastolic (E’) mitral annular velocity (OR 0.75, 95% CI: 0.6–0.94; p=0.01) was significantly associated with cardiovascular hospitalizations. The only independent predictor of recurrent stroke was the ratio of peak velocity of early diastolic transmitral flow to peak velocity of early diastolic mitral annular motion (E/E’) (OR 0.75, 95% CI: 0.6–0.94; p=0.01). E/E’ was independently associated with composite endpoint (death, hospitalization and recurrent stroke) (OR 1.90, 95% CI 1.1–3.2, p=0.01).

Conclusion

The indices of diastolic dysfunction are significantly associated with unfavorable prognosis after ESUS. There is a robust role for outpatient cardiac monitoring especially during the first 2 months after ESUS to detect potential AF.

B-type natriuretic peptide over N-terminal pro-brain natriuretic peptide to predict incident atrial fibrillation after cryptogenic stroke

BACKGROUND AND PURPOSE

B-type natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) are well-known surrogates of atrial fibrillation (AF) detection but studies usually present data on either BNP or NT-proBNP. The aim was to determine and directly compare the validity of the two biomarkers as a tool to predict AF and guide prolonged cardiac monitoring in cryptogenic stroke patients.

METHODS

Non-lacunar acute ischaemic stroke (<72 h) patients over 55 years of age with cryptogenic stroke after standard evaluation were included in the Crypto-AF study and blood was collected. BNP and NT-proBNP levels were determined by automated immunoassays. AF was assessed by 28 days' monitoring. Highest (optimizing specificity) and lowest (optimizing sensitivity) quartiles were used as biomarker cut-offs to build predictive models adjusted by sex and age. The integrated discrimination improvement index (IDI) and DeLong test were used to compare the performance of the two biomarkers.

RESULTS

From 320 patients evaluated, 218 were included in the analysis. AF was detected in 50 patients (22.9%). NT-proBNP (P < 0.001) and BNP (P < 0.001) levels were higher in subjects with AF and their levels correlated (r = 0.495, P < 0.001). BNP showed an increased area under the curve (0.720 vs. 0.669; P = 0.0218) and a better predictive capacity (IDI = 3.63%, 95% confidence interval 1.36%-5.91%) compared to NT-proBNP. BNP performed better than NT-proBNP in a specific model (IDI = 3.7%, 95% confidence interval 0.87%-6.5%), whilst both biomarkers performed similarly in the case of a sensitive model.

CONCLUSIONS

Both BNP and NT-proBNP were increased in cryptogenic stroke patients with AF detection. Interestingly, BNP outperforms NT-proBNP, especially in terms of specificity.

Prolonged ECG with a novel recorder utilizing electrode belt and mobile device in patients with recent embolic stroke of undetermined source: A pilot study

BACKGROUND

Paroxysmal atrial fibrillation (pAF) is a major risk factor for ischemic stroke, but challenging to detect with routine short-term monitoring methods. In this pilot study, we present a novel method for prolonged ECG and screening for pAF in patients with a recent embolic stroke of unknown source (ESUS).

METHODS

Fifteen patients aged ≥ 50 years with a recent ESUS were assigned to wear an external electrode belt-based 1-lead ECG device (Beat2Phone) continuously for 2 weeks (wear time). The device was operated via a mobile phone application in nonhospital conditions. The primary outcome was patient adherence to monitoring. Secondary outcomes were incidence of new pAF, quality-wise comparison to Holter, and usability of the novel ECG monitoring method with Systems Usability Scale (SUS). We also performed a 24- to 48-hr comparison between simultaneous Beat2Phone ECG and a standard Holter in 6 patients.

RESULTS

Wear time of Beat2Phone device was over 80% in 5 (33.3%) patients, 50%-80% in 7 (46.6%) patients, and less than 50% in 3 (20%) patients. We detected pAF ≥ 30 s in 1 patient (6.7%). In the simultaneous monitoring with Beat2Phone and Holter, there were a total of 817 (out of 1979) analyzable periods of sinus rhythm or premature atrial or ventricular beats (Cohen's Kappa coefficient 0.92 ± 0.02 between Beat2Phone and Holter), and no pAF events. Beat2Phone ECG showed remarkable SUS scores in user evaluations (average score: 81.4 out of 100 on SUS).

CONCLUSIONS

Beat2Phone device was easy to use among ESUS patients and in optimal conditions provided high-quality 1-lead ECG signal for diagnosing pAF.

CLINICAL TRIAL REGISTRATION

The study was not registered, as it was a nonrandomized single-arm pilot study.