Subclinical Atrial Fibrillation and the Risk of Recurrent Ischemic Stroke

Age-Dependent Detection of Atrial Fibrillation with Implantable Cardiac Monitors in Patients with Cryptogenic Stroke

Background  Continuous monitoring using implantable cardiac monitors (ICMs) results in atrial fibrillation (AF) detection rates of up to 30% in patients with cryptogenic stroke (CS). Although higher age is an independent risk factor for AF, there are no age-specific recommendations for the implantation of ICM. Objective  The aim of this study was to analyze age-related AF rates in patients with CS and continuous rhythm monitoring, to determine the rates of oral anticoagulation (OAC) and recurrent cerebrovascular events (stroke or transient ischemic attack) in patients with ICM-detected AF, and to describe the temporal relationship of AF detection and recurrent cerebrovascular events. Methods  In this observational study, patients with CS provided with ICMs were systematically followed. All patients underwent 72-hour electrocardiography monitoring, transcranial Doppler ultrasound, and transthoracic echocardiography prior to ICM insertion. Follow-up included a regular outpatient presentation every 3 months with medical history, physical examination, and interrogation of the ICM. Results  One-hundred eighty-six patients (mean age: 65 ± 12 years, 54% female) were included in this analysis. AF was detected in 6, 27, 56, and 65% ( p  < 0.001) of patients aged less than 60, 60 to 69, 70 to 79, and more than or equal to 80 years, respectively. All patients with AF under 60 years had an impaired left ventricular systolic function. OAC was initiated in 85% of the patients with AF. Recurrent cerebrovascular events occurred in 34 patients of whom 14 had a diagnosis of AF. In nine patients, AF was diagnosed before the occurrence of a recurrent cerebrovascular event. Conclusion  AF prevalence increased with age and was absent in CS patients younger than 60 years and with preserved left ventricular ejection fraction. The temporal relationship of AF and recurrent cerebrovascular events was weak.

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.

Risk of Atrial Fibrillation and Adverse Outcomes in Patients With Cardiac Implantable Electronic Devices

BACKGROUND AND OBJECTIVES

Comprehensive epidemiological data are lacking on the incident atrial fibrillation (AF) in patients with cardiac implantable electronic devices (CIEDs). This study aimed to examine the incidence, risk factors, and AF-related adverse outcomes of patients with CIEDs.

METHODS

This was an observational cohort study that analyzed patients without prevalent AF who underwent CIED implantation in 2009-2018 using a Korean nationwide claims database. The subjects were divided into three groups by CIED type and indication: pacemaker (n=21,438), implantable cardioverter defibrillator (ICD)/cardiac resynchronization therapy (CRT) with heart failure (HF) (n=3,450), and ICD for secondary prevention without HF (n=2,146). The incidence of AF, AF-associated predictors, and adverse outcomes were evaluated.

RESULTS

During follow-up, the incidence of AF was 4.3, 7.3, and 5.1 per 100 person-years in the pacemaker, ICD/CRT with HF, and ICD without HF cohorts, respectively. Across the three cohorts, older age and valvular heart disease were commonly associated with incident AF. Incident AF was consistently associated with an increased risk of ischemic stroke (3.8-11.4-fold), admission for HF (2.6-10.5-fold), hospitalization for any cause (2.4-2.7-fold), all-cause death (4.1-5.0-fold), and composite outcomes (3.4-5.7-fold). Oral anticoagulation rates were suboptimal in patients with incident AF (pacemaker, 51.3%; ICD/CRT with HF, 51.7%; and ICD without HF, 33.8%, respectively).

CONCLUSIONS

A substantial proportion of patients implanted CIED developed newly diagnosed AF. Incident AF was associated with a higher risk of adverse events. The importance of awareness, early detection, and appropriate management of AF in patients with CIED should be emphasized.

Stroke Recurrence in Embolic Stroke of Undetermined Source Without Atrial Fibrillation on Invasive Cardiac Monitoring

BACKGROUND

More than half of patients with embolic stroke of undetermined source (ESUS) suffer from recurrent ischaemic stroke, despite the absence of atrial fibrillation (AF) on invasive cardiac monitoring (ICM). This study investigated the predictors and prognosis of recurrent stroke in ESUS without AF on ICM.

METHOD

This prospective study included patients with ESUS at two tertiary hospitals from 2015 to 2021 who underwent comprehensive neurological imaging, transthoracic echocardiography, and inpatient continuous electrographic monitoring for ≥48 hours prior to ICM for definitive exclusion of AF. Recurrent ischaemic stroke, all-cause mortality, and functional outcome by the modified Rankin scale (mRS) at 3 months were evaluated in patients without AF.

RESULTS

Of 185 consecutive patients with ESUS, AF was not detected in 163 (88%) patients (age 62±12 years, 76% men, 25% prior stroke, median time to ICM insertion 26 [7, 123] days), and stroke recurred in 24 (15%) patients. Stroke recurrences were predominantly ESUS (88%), within the first 2 years (75%), and involved a different vascular territory from qualifying ESUS (58%). Pre-existing cancer was the only independent predictor of recurrent stroke (adjusted hazard ratio [AHR] 5.43, 95% CI 1.43-20.64), recurrent ESUS (AHR 5.67, 95% CI 1.15-21.21), and higher mRS score at 3 months (ß 1.27, 95% CI 0.23-2.42). All-cause mortality occurred in 17 (10%) patients. Adjusting for age, cancer, and mRS category (≥3 vs <3), recurrent ESUS was independently associated with more than four times greater hazard of death (AHR 4.66, 95% CI 1.76-12.34).

CONCLUSIONS

Patients with recurrent ESUS are a high-risk subgroup. Studies elucidating optimal diagnostic and treatment strategies in non-AF-related ESUS are urgently required.

Managing high-risk atrial fibrillation patients with multiple comorbidities

Atrial fibrillation (AF) patients are often high risk being elderly and having multiple comorbidities. Many risk factors are established to be associated with new onset incident AF, as well as AF-related complications such as stroke and hospitalisations. Multimorbidity AF patients are high risk and require a holistic approach to care, which should be proactively managing with an integrated care or holistic approach as per the ABC (atrial fibrillation better care) pathway.

Early rhythm control and the risks of ischaemic stroke, heart failure, mortality and adverse events when performed early (<3 months)

BACKGROUND

In EAST-AFNET 4 trial, early rhythm control was associated with better clinical outcomes for patients with atrial fibrillation (AF). However, whether the better outcomes of patients assigned to rhythm control were solely due to "early" intervention or because of more regular and structured follow up was unclear.

OBJECTIVE

To investigate whether the findings of EAST trial are applicable to the 'real world' clinical setting, where a less structured management protocol is operated.

METHODS

From 2001 to 2016, 301,064 newly-diagnosed AF patients were identified from Taiwan National Health Insurance Research Database. Among these patients, 62,649 AF patients receiving antiarrhythmic drugs or catheter ablation within 1 year after AF being diagnosed were categorized as the early rhythm control group, and the remaining 238,415 patients were defined as usual care group. Risk of clinical events were compared.

RESULTS

Compared to usual care, early rhythm control was associated with a lower adjusted risk of ischemic stroke(aHR 0.771; p<0.001), heart failure(aHR 0.851; p<0.001), acute myocardial infarction(aHR 0.915; p<0.001), mortality(aHR 0.794; p<0.001) and composite adverse events(aHR 0.823; p<0.001). Compared to usual care, the lower risks of ischemic stroke(aHR 0.746), heart failure(aHR 0.819), mortality(aHR 0.777) and composite adverse events(aHR 0.802) associated with early rhythm control were even more evident when performed early (<3months)(pint<0.001). Principal results were generally consistent for majority of subgroups studied and among the cohort after propensity matching.

CONCLUSIONS

Early rhythm control, especially when performed earlier (<3months), was associated with a lower risk of adverse events than usual care among patients with early AF.

Comparing Outcomes in Asymptomatic and Symptomatic Atrial Fibrillation: A Systematic Review and Meta-Analysis of 81,462 Patients

BACKGROUND

In atrial fibrillation (AF) patients, the presence of symptoms can guide the decision between rate or rhythm control therapy, but it is still unclear if AF-related outcomes are determined by symptomatic status of their clinical presentation.

METHODS

We performed a systematic review and metanalysis following the PRISMA recommendations on available studies that compared asymptomatic to symptomatic AF reporting data on all-cause mortality, cardiovascular death, and thromboembolic events (TEs). We included studies with a total number of patients enrolled equal to or greater than 200, with a minimum follow-up period of six months.

RESULTS

From the initial 5476 results retrieved after duplicates' removal, a total of 10 studies were selected. Overall, 81,462 patients were included, of which 21,007 (26%) were asymptomatic, while 60,455 (74%) were symptomatic. No differences were found between symptomatic and asymptomatic patients regarding the risks of all-cause death (odds ratio (OR) 1.03, 95% confidence interval (CI) 0.81-1.32), and cardiovascular death (OR 0.87, 95% CI 0.54-1.39). No differences between symptomatic and asymptomatic groups were evident for stroke (OR 1.22, 95% CI 0.77-1.93) and stroke/TE (OR 1.06, 95% CI 0.86-1.31) risks.

CONCLUSIONS

Mortality and stroke/TE events in AF patients were unrelated to symptomatic status of their clinical presentation. Adoption of management strategies in AF patients should not be based on symptomatic clinical status.