Subclinical Atrial Fibrillation Research Articles

Management of atrial arrhythmias identified by cardiac devices.

Implantable cardiac devices have shown that atrial fibrillation (AF) is more frequent than previously assumed, with subclinical, asymptomatic, self-limiting manifestations called atrial high-rate events (AHREs) or subclinical AF. The clinical significance and correct therapeutic management of these episodes of subclinical AF is less well defined than in the case of clinically manifest AF. Two important randomized studies on the topic have recently been published, NOAH-AFNET 6 and ARTESIA, which, however, have not definitively clarified the topic. In patients with AHRE or subclinical AF, the average thrombo-embolic risk is lower than that in patients with clinically manifest AF and is ∼1%. For this reason, in these patients, the possibility that the benefit of anticoagulant therapy is overshadowed by the risk of bleeding is very high. Therefore, while waiting for new tools that allow a better stratification of low-risk patients, we must rely on individual clinical evaluation and overcome the qualitative dichotomy (AHRE yes vs. AHRE no), preferring instead an approach that is as quantitative as possible and takes into account the number of episodes, their duration, and the patient's CHADSVASC score, before deciding, in each individual case, whether or not to use anticoagulant therapy.

Implications for clinical decision-making of the NOAH-AFNET 6 and ARTESiA studies: what risk-benefit ratio of anticoagulation in patients with subclinical atrial fibrillation?

Implications for clinical decision-making of the NOAH-AFNET 6 and ARTESiA studies: what risk-benefit ratio of anticoagulation in patients with subclinical atrial fibrillation?

Expert opinion of the Heart Rhythm Association of the Polish Cardiac Society and the Polish Neurological Society on evidence-driven implementation of implantable loop recorders in Poland.

Implantable loop recorders (ILR) are considered increasingly helpful in diagnosing cardio-neurological conditions, especially if arrhythmic events are of high clinical importance but are unlikely to be captured by standard methods of electrocardiogram recording due to the low frequency of events and short duration of a single event. The compelling evidence from randomized trials and observational studies strongly supports ILR utilization in patients after cryptogenic stroke or transient ischemic attack and in patients with recurrent transient loss of consciousness of unknown origin. These two groups of patients are expected to gain the most from initiating ILR-driven clinically effective management strategies. Stroke or transient ischemic attack survivors with detected subclinical atrial fibrillation can be switched from antiplatelets to anticoagulants, whilst patients with recurrent syncope may avoid severe injuries and/or substantial impairment of their quality of life. This joint opinion of the Heart Rhythm Association of the Polish Cardiac Society and experts from the Polish Neurological Society summarizes the up-to-date rationale for using ILR in everyday clinical practice and describes the road map for implementing this technology in Poland. Special emphasis is placed on the most recent guidelines issued by both cardiological and neurological scientific societies.

Atrial Fibrillation Burden: Impact on Stroke Risk and Beyond.

Atrial fibrillation (AF) is an important independent risk factor for stroke. Current guidelines handle AF as a binary entity with risk driven by the presence of clinical risk factors, which guides the decision to treat with an oral anticoagulant. Recent studies in the literature suggest a dose-response relationship between AF burden and stroke risk, in both clinical AF and subclinical atrial fibrillation (SCAF), which differs from current guidance to disregard burden and utilize clinical risk scores alone. Within clinical classification and at the same risk levels in various scores, the risk of stroke increases with AF burden. This opens the possibility of incorporating burden into risk profiles, which has already shown promise. Long-term rhythm monitoring is needed to elucidate SCAF in patients with stroke. Recent data from randomized trials are controversial regarding whether there is an independent risk from AF episodes with a duration of less than 24 h, including the duration of SCAF greater than six minutes but less than 24 h.

Subclinical atrial fibrillation patients, who are the best candidates for oral anticoagulant therapy?

Subclinical atrial fibrillation patients, who are the best candidates for oral anticoagulant therapy?

Subclinical atrial fibrillation in embolic stroke of undetermined source: Management and stroke recurrence

Subclinical atrial fibrillation (SAF) represents the most prevalent underlying etiology detected after an embolic stroke of undetermined source (ESUS). Investigating SAF is strongly recommended during the diagnostic work-up. The efficacy of oral anticoagulant (OAC) therapy in reducing the risk of stroke recurrence post-SAF detection remains a conundrum. Thus, our study aimed to analyze the management of secondary antithrombotic prophylaxis and the rate of 12-month stroke recurrence in real-life ESUS patients. We retrospectively analyzed clinical, radiographic, and echocardiographic findings of patients with ESUS who underwent non-implantable 2-week electrocardiogram (ECG) monitoring after discharge. Episodes of SAF of any duration were considered diagnostic. Antithrombotic treatment at hospital discharge and after ECG monitoring, as well as 12-month recurrence, were registered. We compared the rate of stroke recurrence between patients with and without detection of SAF. One hundred and fifty-nine patients (75 females) with a median age of 73.5 (interquartile range [IQR] = 66.75 – 79) years represented the study population. At hospital discharge, 96.9% of patients received antiplatelet therapy as secondary antithrombotic prophylaxis. SAF was detected in 82 patients (51.5%), and OAC was prescribed in 98.6% of them. The median time from stroke onset to OAC prescription was 143 (IQR = 94 – 178) days. Overall, 12-month stroke recurrence occurred in eight patients (5%). The stroke recurrence rate was lower in patients prescribed OAC compared with those not prescribed it, although the difference was not significant (3.7% vs. 6.25%; P = 0.7202). In our study, OACs prescribed post-SAF detection in patients with ESUS reduced, but not significantly, the risk of stroke recurrence. Future research and prospective multicenter studies are warranted.

Risk of Subclinical Atrial Fibrillation in Patients with Cardiac Implantable Electronic Devices after COVID-19 Infection: A Single-Center Study

Objective: To evaluate the risk of subclinical atrial fibrillation (SCAF) in patients with cardiac implantable electronic devices (CIEDs) after COVID-19 infection. Materials and Methods: The authors retrospectively enrolled patients receiving CIEDs with atrial leads at the device clinic between January 2022 and September 2023. Patients with 12-lead ECG documented atrial fibrillation, atrial flutter, or atrial tachycardia were excluded. The authors classified these patients as COVID-19 and non-COVID-19 groups. The outcome was the new onset and/or 20% increased episodes of the longest SCAF duration. The authors compared the outcome using a chi-square or Fisher’s exact test between both groups. Results: One hundred thirty-two patients were enrolled. Of the 132 patients, 44 patients were in COVID-19 group and 88 patients were in non-COVID-19 group. The average age was 67.6 years. About one-third of these patients were males. Most of these patients had hypertension and dyslipidemia. The average follow-up time was 9.3 months. Eighteen patients (40.9%) had the longest SCAF duration in the COVID-19 group, while 23 patients (26.1%) had the longest SCAF duration in the non-COVID-19 group. More patients in the COVID-19 group had the longest SCAF duration than those in non-COVID-19 group with no statistical significance (odds ratio 1.96, 95% confidence interval 0.91 to 4.21, p=0.13). Conclusion: Patients with a history of previous COVID-19 infection receiving CIEDs had no significantly increased risk of SCAF. Keywords: COVID-19; CIEDs; Subclinical atrial fibrillation; AHRE burden; Atrial high-rate episode

What Do We Really Know About the Effect of Prolonged Heart Rhythm Monitoring After Stroke?

The bulk of the current knowledge on atrial fibrillation (AF)-associated stroke risk and benefit of oral anticoagulation derives from studies on patients with clinically diagnosed AF. Subclinical AF (SCAF), defined as AF discovered during the interrogation of prolonged heart monitoring, is often asymptomatic and short-lasting, is associated with increased stroke risk compared with sinus rhythm, and may progress to clinical AF. Despite the extensive screening for and treatment of SCAF, especially in secondary stroke prevention, the net benefit of this practice is not established. Recent studies of SCAF have provided new insights: (1) SCAF is extremely common and may sometimes indicate physiological findings, (2) the stroke risk associated with SCAF is lower than that of clinically detected AF, and (3) any benefit on stroke risk may be countered by increased bleeding risk (no net benefit). How should we interpret the latest knowledge in the setting of poststroke AF screening and prevention?

In subclinical AF, apixaban reduced stroke or systemic embolism but increased major bleeding vs. aspirin at 3.5 y.

Healey JS, Lopes RD, Granger CB, et al; ARTESIA Investigators. Apixaban for stroke prevention in subclinical atrial fibrillation. N Engl J Med. 2024;390:107-117. 37952132.

Atrial Fibrillation and Early Vascular Aging: Clinical Implications, Methodology Issues and Open Questions-A Review from the VascAgeNet COST Action.

Atrial fibrillation (AF), the most common cardiac arrhythmia, is associated with adverse CV outcomes. Vascular aging (VA), which is defined as the progressive deterioration of arterial function and structure over a lifetime, is an independent predictor of both AF development and CV events. A timing identification and treatment of early VA has therefore the potential to reduce the risk of AF incidence and related CV events. A network of scientists and clinicians from the COST Action VascAgeNet identified five clinically and methodologically relevant questions regarding the relationship between AF and VA and conducted a narrative review of the literature to find potential answers. These are: (1) Are VA biomarkers associated with AF? (2) Does early VA predict AF occurrence better than chronological aging? (3) Is early VA a risk enhancer for the occurrence of CV events in AF patients? (4) Are devices measuring VA suitable to perform subclinical AF detection? (5) Does atrial-fibrillation-related rhythm irregularity have a negative impact on the measurement of vascular age? Results showed that VA is a powerful and independent predictor of AF incidence, however, its role as risk modifier for the occurrence of CV events in patients with AF is debatable. Limited and inconclusive data exist regarding the reliability of VA measurement in the presence of rhythm irregularities associated with AF. To date, no device is equipped with tools capable of detecting AF during VA measurements. This represents a missed opportunity to effectively perform CV prevention in people at high risk. Further advances are needed to fill knowledge gaps in this field.

Anticoagulation instauration in device-detected subclinical atrial fibrillation: what impact does it have on outcomes?

Anticoagulation instauration in device-detected subclinical atrial fibrillation: what impact does it have on outcomes?

Epicardial adipose tissue and subclinical incident atrial fibrillation as detected by continuous monitoring: a cardiac magnetic resonance imaging study

Epicardial adipose tissue (EAT) has endocrine and paracrine functions and has been associated with metabolic and cardiovascular disease. This study aimed to investigate the association between EAT, determined by cardiac magnetic resonance imaging (CMR), and incident atrial fibrillation (AF) following long-term continuous heart rhythm monitoring by implantable loop recorder (ILR). This study is a sub-study of the LOOP study. In total, 203 participants without a history of AF received an ILR and underwent advanced CMR. All participants were at least 70 years of age at inclusion and had at least one of the following conditions: hypertension, diabetes, previous stroke, or heart failure. Volumetric measurements of atrial- and ventricular EAT were derived from CMR and the time to incident AF was subsequently determined. A total of 78 participants (38%) were diagnosed with subclinical AF during a median of 40 (37–42) months of continuous monitoring. In multivariable Cox regression analyses adjusted for age, sex, and various comorbidities, we found EAT indexed to body surface area to be independently associated with the time to AF with hazard ratios (95% confidence intervals) up to 2.93 (1.36–6.34); p = 0.01 when analyzing the risk of new-onset AF episodes lasting ≥ 24 h. Atrial EAT assessed by volumetric measurements on CMR images was significantly associated with the incident AF episodes as detected by ILR.

Balancing the benefits and risks of anticoagulation in patients with subclinical atrial fibrillation.

Balancing the benefits and risks of anticoagulation in patients with subclinical atrial fibrillation.

Challenging anticoagulation decisions in atrial fibrillation: a narrative review.

Atrial fibrillation (AF) is common and warrants consideration of oral anticoagulant (OAC) medication. Usually, the decision is straightforward, following the pathway outlined in the European Society of Cardiology's guideline; however, certain situations fall outside of this evidence base - such as a diagnosis of subclinical AF made via implanted devices or wearable electrocardiogram monitors, or alternatively diagnosis of 'secondary AF' following a major stressor. Subclinical AF is associated with stroke, though not to the extent of clinical AF, and the benefits of anticoagulation appear to be lower. Longer episodes are more clinically meaningful, and recent randomised controlled trials have demonstrated that some patients derive benefit from OAC. Similarly, when AF is triggered by sepsis or non-cardiac surgery, specific evidence supporting OAC initiation is lacking and clinician behaviour is variable. Observational data demonstrate poorer outcomes in these patients, implying that the perception of a transient, reversible phenomenon may not be correct. Contrastingly, cardiac surgery very frequently induces AF, and the benefits of anticoagulation rarely outweigh the risks of bleeding. Following ischaemic stroke, recent evidence suggests that early (re-)initiation of OAC should be considered as this does not increase the risk of haemorrhagic transformation as previously hypothesised. This narrative review summarises the available literature and outlines, where possible, practical advice for clinicians facing these common clinical dilemmas.

Anticoagulation-Associated Bleeding in Patients Screened for Atrial Fibrillation versus Usual Care-A Post Hoc Analysis from the LOOP Study.

Background Atrial fibrillation (AF) prevalence is rising; however, data on the bleeding risks associated with the detection of subclinical AF are needed. Objective Our objective was to determine the bleeding increment associated with implantable loop recorder (ILR) screening for subclinical AF and subsequent anticoagulation initiation compared with usual care. Methods This post hoc study utilized LOOP trial data from 6,004 elderly patients with stroke risks randomized to either ILR ( n = 1,503) or usual care ( n = 4,503). The mean follow-up time was 64.5 months, and none were lost to follow-up. The primary exposure was the initiation of oral anticoagulation, and the main outcome was the risk of major bleeding events following initiation of oral anticoagulants (OACs), determined by time-dependent cox regression. Second, we investigated antithrombotic prescription patterns and major bleeding events after antiplatelet treatment and in subgroups. Results OAC was initiated in 1,019 participants with a mean age (years) of 78.8 (± 4.67) in control versus 77.0 (± 4.84) in ILR, p < 0.0001. Altogether did 202 participants end or pause OAC treatment. Among AF patients (n = 910) had 40 (28%) completely ended OAC and 105 (72%) temporarily paused OAC during follow-up. Major bleeding events totaled 221 (3.7%). Forty-seven major bleeding events followed an OAC initiation in 1,019 participants (4.6%); 26 versus 21 events in the control and ILR groups, respectively. The hazard ratio (HR) for major bleeding after OAC initiation compared with before initiation was 2.08 (1.50-2.90) p < 0.0001 overall, 2.81 (1.82-4.34) p < 0.0001 for control and 1.32 (0.78-2.23) p = 0.31 for the ILR group ( p = 0.07 for interaction). Antiplatelet treatment resulted in an overall adjusted HR of 1.3 (0.96-1.75) p = 0.09. For OAC users aged ≥75 years in the ILR group, the rate of major bleeding was 1.73 (0.92-2.96) compared with 0.84 (0.36-1.66) for an age <75 years, and the rate of the corresponding control subgroup aged ≥75 years was 2.20 (1.23-3.63) compared with 1.64 (0.82-2.93) for an age <75 years. Conclusion The individual risk of major bleeding increased twofold after initiation of oral anticoagulation for all patients in this study. However, the patients screened for subclinical AF did not have a higher bleeding risk after initiation of anticoagulation compared with those in usual care. Trial Registration: The LOOP study is registered at ClinicalTrials.gov, identifier: NCT020364 50.

Embolic stroke of undetermined source - ESUS: a new challenge for the cardiologist

Embolic stroke of undetermined source (ESUS) is a new clinical entity which requires an accurate diagnostic work-up. The involvement of the cardiologist in this challenge is of paramount importance as in many cases an occult cardioembolic source is detectable. In the absence of subclinical atrial fibrillation detectable by prolonged ECG monitoring, potential causes of ESUS include atrial cardiomyopathy, left ventricular dysfunction or heart failure, aortic plaques and patent foramen ovale. The assessment of a causal relationship between these cardiac abnormalities and ESUS is often a difficult challenge and the randomized clinical trials performed so far failed to demonstrate a superiority of direct oral anticoagulants (DOAC) over aspirin. In selected individual patients with heart failure in sinus rhythm with high CHA2DS2-VASc score, or aortic plaques with thrombotic component, oral anticoagulation with DOAC might be considered even in the absence of evidence from randomized clinical trials.

Prevalence of Subclinical Atrial Fibrillation in Heart Failure With Preserved Ejection Fraction

BackgroundAtrial fibrillation (AF) is common in patients with heart failure with preserved ejection fraction (HFpEF) and is associated with poorer clinical outcomes. The prevalence of subclinical AF in patients with HFpEF remains unknown. ObjectivesThe aim of this study was to determine whether subclinical AF was more prevalent in individuals with HFpEF than in individuals without histories of heart failure (HF). MethodsPatients with HFpEF with no prior diagnoses of AF were screened for subclinical AF, and the prevalence of subclinical AF was compared with that among control subjects without HF drawn from MESA (Multi-Ethnic Study of Atherosclerosis) who underwent the same electrocardiographic monitoring. Multivariable logistic regression was used to adjust for demographic and clinical comorbidities. ResultsNinety patients with HFpEF and 1,230 MESA participants were included. Patients with HFpEF were younger (median age 69 years [Q1-Q3: 63-76 years] vs 72 years [Q1-Q3: 66-80 years]; P = 0.02), more obese (median body mass index 36 kg/m2 [Q1-Q3: 30-45 kg/m2] vs 27 kg/m2 [Q1-Q3: 24-30 kg/m2]; P < 0.001), and more likely to have diabetes (34% vs 21%; P = 0.01). The prevalence of subclinical AF was 8.9% in patients with HFpEF and 4.1% in non-HF participants. After multivariable adjustment for age, sex, race, body mass index, diabetes, smoking, and total analyzable time on electrocardiographic monitor, there was a significantly higher odds of subclinical AF in patients with HFpEF compared with MESA (OR: 3.01; 95% CI: 1.13-7.99; P = 0.03). ConclusionsPatients with HFpEF had a higher prevalence of subclinical AF than participants without HF from a community-based study. Screening for atrial arrhythmias may be appropriate among patients with HFpEF for timely initiation of thromboembolic prophylaxis and may identify individuals at greater risk for clinical decompensation.

Atrial Fibrillation Detection and Load: Knowledge Gaps Related to Stroke Prevention.

Atrial fibrillation is a major cause of ischemic stroke. Technological advances now support prolonged cardiac rhythm monitoring using either surface electrodes or insertable cardiac monitors. Four major randomized controlled trials show that prolonged cardiac monitoring detects subclinical paroxysmal atrial fibrillation in 9% to 16% of patients with ischemic stroke, including in patients with potential alternative causes such as large artery disease or small vessel occlusion; however, the optimal monitoring strategy, including the target patient population and the monitoring device (whether to use an event monitor, insertable cardiac monitor, or stepped approach) has not been well defined. Furthermore, the clinical significance of very short duration paroxysmal atrial fibrillation remains controversial. The relevance of the duration of monitoring, burden of device-detected atrial fibrillation, and its proximity to the acute ischemic stroke will require more research to define the most effective methods for stroke prevention in this patient population.

Nurse-driven protocol for the management and follow-up of subclinical atrial fibrillation episodes in pacemaker patients

Abstract Background Atrial high-rate episodes (AHREs) compatible with atrial fibrillation (AF) detected in pacemakers are associated with an increased risk of stroke. Nurses trained in pacemaker (PM) follow-up can detect theses AHREs during patient’ scheduled visits and provide the best care option to the patients. Purpose To evaluate a nurse protocol applied in these patients focused on a) identifying those with AHREs and taking into account the timing of these events and their duration, and b) provide the best care and follow-up then after. Methods and Results To create our protocol, we evaluated PM patients without a previous history of AF and classified the incidence of AHREs into 3 groups: &amp;gt;5 minutes to 24 hours; &amp;gt;24 hours and patients who are in clinical AF (documented on ECG) at the time of the visit. We also evaluate the time elapsed since PM implantation (£ 3 months vs &amp;gt; 3 months) and the type of atrial electrode fixation (active vs passive). In a prior study we analyzed 110 patients with AHREs &amp;gt;5 minutes and &amp;lt;24 hours (56% male, age 75 ± 9 years, mean CHA2DS2VACS scores of 3.5 ± 1.5). After 24 ± 9 months, 40 patients (36.4%) presented AHREs, and CT images showed ischemic brain lesions in 26 of them (23.6%). The presence of AHREs at 3 months was more frequent in patients with a recent MP implantation (17% vs 4.5%) and with a significant relationship with the type of active fixation of the electrode. The presence of ischemic lesions on CT was related to the detection of AHREs during follow-up, but not with AHREs in the first 3 months. Therefore, we designed a dedicated protocol for follow-up in these patients (AHREs &amp;gt;5 minutes and &amp;lt;24 hours) after PM implantation with repetitive follow-up visits assessing the evolution of AHREs. In cases of &amp;gt;24 hours and those with ECG documented AF, Guidelines recommendations were followed. Conclusions In PM patients, the presence of AHREs might be related to serious clinical complications. On the other hand, AHREs occur regularly during the first 3 months after PM implantation, maybe related to the procedure itself and the use of active fixation for the atrial lead. AHREs in this period may not be related to major complications and individual risk should be carefully assessed before starting anticoagulation. A dedicated protocol for closer follow-up visits in these patients might help to identify those at risk and prevent clinical events.

The importance of active rhythm monitoring in patients with renal infarction: Korean national health insurance registry

Abstract Background/Introduction Several studies reported that approximately 50% of renal infraction (RI) is caused by cardioembolic disease, particularly associated with atrial fibrillation (AF). However, in the Korean national health insurance database (NHIS), from 2013 to 2019, the prevalence of AF in patients with RI was only 15%. So, we aimed to analyze the incidence of newly developed AF in RI patients. Method This nationwide population-based retrospective cohort study included 5,200 patients with RI using the NHIS database from 2002 to 2012. We analyzed the incidence rate of AF during 12 months among the patients without previous history of AF. We selected clinical events after three months of RI diagnosis to exclude cases diagnosed by initial screening or with previously missed diagnosis of AF. The definition of RI, AF, and comorbidities use the ICD-10-CM codes. Result During the total follow-up period (median 2.5 years, interquartile range 1.04-4.25), AF occurred in 19.1% of RI patients (n=993). Most cases (n=837, 16.1%) occurred within a year, and the incidence of AF was 3.965 per 10,000 person-year. Patients with newly developed AF had a higher proportion of older age than those without AF (64.1 vs. 57.3 years, P&amp;lt;0.001). The prevalence of comorbidities, including hypertension (HTN), ischemic heart disease (IHD), and heart failure (HF), was higher in those with AF. The independent predictors of AF were age (adjusted hazard ratio [aHR] 1.05, 95% CI 1.04-1.05, P&amp;lt;0.001), male (aHR 1.26, 95% CI 1.09-1.45, P=0.002), body mass index (BMI) (aHR 1.04, 95% CI 1.02-1.06, P &amp;lt;0.001), current smoker (aHR 1.20, 95% CI 1.03-1.40, P =0.023), IHD (aHR 1.20, 95% CI 1.00-1.45, P =0.050) and HF (aHR 1.70, 95% CI 1.25-2.33, P =0.001). Additionally, the incidence of all-cause death was 14.264 per 10,000 person-year during the follow-up period. Conclusion Even if AF is not diagnosed in the initial screening after diagnosis of RI, the physician should consider active rhythm monitoring to detect subclinical AF for optimal management in these patients. Especially it might be helpful to reduce the burden of recurrent embolic events in those with risk factors, such as older age, male, higher BMI, current smoker, IHD, or HF.Cox regression analysisAtrial fibrillation cumulative incidence