Atrial Fibrillation Burden: Moving Beyond Atrial Fibrillation as a Binary Entity: A Scientific Statement From the American Heart Association

Smartphone app-based approximation of time spent with atrial fibrillation and symptoms in patients after catheter ablation: data from the TeleCheck-AF project

AIMS

Reduction of atrial fibrillation (AF) burden is the preferred outcome measure over categorical AF rhythm recurrence after AF ablation. In this sub-analysis of the TeleCheck-AF project, we tested the feasibility of smartphone app-based approximation of time spent with AF and/or symptoms.

METHODS AND RESULTS

Patients scheduled for at least one teleconsultation during the 12-month follow-up after AF ablation were instructed to use a smartphone photoplethysmography-based application for simultaneous symptom and rhythm monitoring three times daily for 1 week. Proxies of time spent with AF and/or symptoms (% recordings, load, and % days), temporal aggregation of AF and/or symptoms (density), and symptom-rhythm correlation (SRC) were assessed. In total, 484 patients (60% male, 62 ± 9.9 years) were included. Adherence, motivation, and patient satisfaction were high. %AF recordings, AF load, and %AF days (rs = 0.88-0.95) and %symptom recordings, symptom load, and %symptom days (rs = 0.95-0.98) showed positive correlations. The SRC correlated negatively with time spent with symptoms (rs = -0.65-0.90) and with time spent with AF (rs = -0.31-0.34). In patients with paroxysmal AF before ablation and AF during the monitoring period, 87% (n = 39/44) had a low-density score <50% ('paroxysmal AF pattern') while 5% (n = 2/44) had a high-density score >90% ('persistent AF pattern'). Corresponding numbers for patients with persistent AF before ablation were 48% (n = 11/23) and 43% (n = 10/23), respectively.

CONCLUSION

On-demand, app-based simultaneous rhythm and symptom assessment provides objective proxies of time spent with AF and/or symptoms and SRC, which may assist in assessing AF and symptom outcomes after AF ablation.

Atrial fibrillation burden and clinical outcomes following BTK inhibitor initiation

Bruton's tyrosine kinase inhibitors (BTKi) have dramatic efficacy against B-cell malignancies, but link with cardiotoxicity, including atrial fibrillation (AF). Burden, severity, and implications of BTKi-related AF are unknown. Leveraging a large-cohort of consecutive B-cell malignancy patients initiated on BTKi from 2009-2020, we identified patients with extended ambulatory rhythm monitoring. The primary outcome was AF burden after BTKi-initiation. Secondary outcomes included ventricular arrhythmia burden and other arrhythmias. Observed incident-AF rates and burden with next-generation BTKi's were compared to ibrutinib. Multivariable regression defined association between rhythm measures and major adverse cardiac events (MACE), and mortality. There were 98 BTKi-treated patients [38.8% next-generation BTKi's, 14.3% prior-AF], with 28,224 h of monitoring. Median duration BTKi-use was 34 months. Over mean duration 12 days monitoring, 72.4% developed arrhythmias (16.3% incident-AF, 31.6% other SVTs, 14.3% ventricular tachycardia). 14.3% had high AF-burden. AF-burden was similar between ibrutinib and next-generation BTKi's. No single antiarrhythmic-therapy prevented BTKi-related AF. However, antiarrhythmic initiation associated with reduction in arrhythmic burden (P = 0.009). In a multivariable model accounting for traditional cardiovascular risk factors, prior-AF associated with increased post-BTKi AF-burden. In follow-up, high AF burden associated with MACE (HR 3.12, P = 0.005) and mortality (HR 2.97, P = 0.007). Among BTKi-treated patients, high AF burden prognosticates future MACE and mortality risk.

Association Between the Timing of Atrial Fibrillation Detection and Functional Outcome Following Mechanical Thrombectomy

BACKGROUND

Atrial fibrillation detected after stroke (AFDAS) refers to the identification of newly diagnosed atrial fibrillation (AF) following an ischemic stroke in patients without known AF (KAF). The objective of this study was to compare the functional outcomes of patients diagnosed with AFDAS and those with KAF who underwent mechanical thrombectomy.

METHODS AND RESULTS

We conducted a retrospective analysis of patients who underwent mechanical thrombectomy and with either new AF diagnosed during hospitalization or KAF. We compared the baseline characteristics, clinical, and procedure-related variables between those with AFDAS and KAF. The primary outcome was the achievement of functional independence, defined as a modified Rankin Scale score of 0 to 2, at 3 months after stroke. Of the 252 patients, 101 (40.1%) were classified into the AFDAS group. The KAF group exhibited a higher rate of stroke history compared with the AFDAS group (32.5% versus 13.9%; P=0.001). Tandem occlusion was more common in the KAF group (13.2% versus 5.9%), while M2 occlusion was more common in the AFDAS group (11.3% versus 20.8%). The proportion of patients who achieved functional independence was higher in the AFDAS group (37.7% versus 52.5%; P=0.029). Multivariable analysis showed that AFDAS was associated with a favorable functional outcome (odds ratio, 2.67 [95% CI, 1.39-5.14]; P=0.003).

CONCLUSIONS

AFDAS demonstrated a positive association with functional independence in patients with stroke who underwent mechanical thrombectomy and were finally diagnosed to have AF during hospitalization. The observed disparities in occlusion site, intractable thrombus, and history of previous stroke may have contributed to these findings.

Novel Technologies in the Detection of Atrial Fibrillation: Review of Literature and Comparison of Different Novel Technologies for Screening of Atrial Fibrillation

Atrial fibrillation (AF) is globally the most common arrhythmia associated with significant morbidity and mortality. It impairs the quality of the patient's life, imposing a remarkable burden on public health, and the healthcare budget. The detection of AF is important in the decision to initiate anticoagulation therapy to prevent thromboembolic events. Nonetheless, AF detection is still a major clinical challenge as AF is often paroxysmal and asymptomatic. AF screening recommendations include opportunistic or systematic screening in patients ≥65 years of age or in those individuals with other characteristics pointing to an increased risk of stroke. The popularities of well-being and taking personal responsibility for one's own health are reflected in the continuous development and growth of mobile health technologies. These novel mobile health technologies could provide a cost-effective solution for AF screening and an additional opportunity to detect AF, particularly its paroxysmal and asymptomatic forms.

Atrial fibrillation burden: Stepping beyond the categorical characterization

Traditional classifications categorize atrial fibrillation (AF) into paroxysmal, persistent, or permanent, but recent advancements in monitoring have revealed AF as a continuous variable, challenging existing paradigms. AF burden, defined basically as the amount of time spent in AF during a monitored period, has emerged as a crucial metric. This review assesses the evolving landscape of AF burden and its measurement methods, diagnostic modalities, and impact on outcomes. Guidelines suggest individualized approaches, combining AF burden with clinical scores (CHA2DS2-VASc), but studies have challenged this. Addressing the impact of AF burden on patients' quality of life before or after ablation is also crucial. Although continuous monitoring technologies offer promising avenues, the field faces challenges, such as defining clinically relevant thresholds. Future research should focus on refining these, designing trials centered around AF burden, and evaluating the efficacy of interventions in reducing AF burden, ultimately paving the way for personalized management strategies.

The role of atrial fibrillation in vascular cognitive impairment and dementia: epidemiology, pathophysiology, and preventive strategies

The aging population in Europe faces a substantial burden from dementia, with vascular cognitive impairment and dementia (VCID) being a preventable cause. Atrial fibrillation (AF), a common cardiac arrhythmia, increases the risk of VCID through mechanisms such as thromboembolism, cerebral hypoperfusion, and inflammation. This review explores the epidemiology, pathophysiology, and preventive strategies for AF-related VCID. Epidemiological data indicate that AF prevalence rises with age, affecting up to 12% of individuals over 80. Neuroimaging studies reveal chronic brain changes in AF patients, including strokes, lacunar strokes, white matter hyperintensities (WMHs), and cerebral microbleeds (CMHs), while cognitive assessments show impairments in memory, executive function, and attention. The COVID-19 pandemic has exacerbated the underdiagnosis of AF, leading to an increase in undiagnosed strokes and cognitive impairment. Many elderly individuals did not seek medical care due to fear of exposure, resulting in delayed diagnoses. Additionally, reduced family supervision during the pandemic contributed to missed opportunities for early detection of AF and related complications. Emerging evidence suggests that long COVID may also elevate the risk of AF, further complicating the management of this condition. This review underscores the importance of early detection and comprehensive management of AF to mitigate cognitive decline. Preventive measures, including public awareness campaigns, patient education, and the use of smart devices for early detection, are crucial. Anticoagulation therapy, rate and rhythm control, and addressing comorbid conditions are essential therapeutic strategies. Recognizing and addressing the cardiovascular and cognitive impacts of AF, especially in the context of the COVID-19 pandemic, is essential for advancing public health.

Determinants and impact of postoperative atrial fibrillation burden during 2.5 years of continuous rhythm monitoring after cardiac surgery: Results from the RACE V prospective cohort study

BACKGROUND

Early postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with late-POAF recurrences. However, little is known about the burden of POAF and its potential impact on long-term outcomes after cardiac surgery, particularly on the risk for late-POAF recurrences.

OBJECTIVE

The purpose of this study was to establish the distribution of POAF burden and to determine the association between early-POAF burden and late-POAF recurrences during 2.5 years of continuous rhythm monitoring after cardiac surgery in patients with and without preoperative history of atrial fibrillation (AF).

METHODS

Patients undergoing cardiac surgery were prospectively enrolled and postoperatively continuously monitored with an implantable loop recorder for 2.5 years. All patients underwent extensive clinical assessment at baseline. During follow-up, all AF episodes were registered, and AF associated metrics, such as burden, were calculated for different time intervals. Early-POAF was defined as AF within first 90 postoperative days and late-POAF as AF after this interval.

RESULTS

A total of 98 consecutive patients were included. POAF burden during the early postoperative phase was significantly higher compared to the late postoperative phase (P <.001). The longest individual POAF episode was strongly associated with increased POAF burden after adjusting for age, sex, and AF history (standardized Beta: 0.91, P <.001). Also, early-POAF burden was associated with late-POAF (re)occurrence after adjusting for age, sex, AF history (adjusted hazard ratio 1.93, 95% confidence interval 1.42-2.62, P <.001).

CONCLUSION

POAF burden was significantly associated with the longest individual POAF episode duration. Additionally, greater early-POAF burden was associated with increased late-POAF incidence, highlighting its potential in estimating the risk for long-term POAF recurrences.

Novel stroke prevention strategies following catheter ablation for atrial fibrillation

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

Associations Between Changes in Maximum Daily Atrial Fibrillation Duration, Ischemic Stroke, and Mortality

BACKGROUND

Atrial fibrillation (AF) outcomes are strongly associated with continuous measures of AF burden.

OBJECTIVES

This study sought to assess the association between changes in maximum daily AF duration (MDAFD) and stroke or mortality in patients with cardiac implantable electronic devices (CIEDs).

METHODS

The Optum deidentified electronic health record data set (2007-2021) was linked with the Medtronic CareLink heart rhythm database. Patients with CIEDs and health care activity recorded in the electronic health record were included, excluding those with oral anticoagulation prescription. MDAFD was assessed 30 days post implant (baseline period) and 30 days before censoring or an event. HRs for the primary analysis were adjusted for components of CHA2DS2-VASc, baseline MDAFD category, and chronic kidney disease.

RESULTS

Of 26,400 patients (age 68 ± 13 years; follow-up 2.6 ± 1.6 years) analyzed, 2,544 (9.6%) had AF during baseline. Increased (vs stable or decreased) MDAFD category in follow-up was associated with a higher adjusted rate of stroke and mortality (HR: 1.80; 95% CI: 1.61-2.01). There was no association between decreased MDAFD in follow-up and the combined endpoint (HR: 0.82; 95% CI: 0.68-1.00). Subgroup analysis by baseline MDAFD category demonstrated that increased MDAFD in follow-up was associated with a greater risk of stroke or mortality among patients with no AF at baseline, and decreased MDAFD in follow-up was associated with a lower risk of stroke or mortality among patients with baseline MDAFD of 1 to <5.5 hours and 5.5 to <23.5 hours.

CONCLUSIONS

In CIED patients not on oral anticoagulation, increased MDAFD in follow-up was associated with a higher rate of stroke and mortality. These results suggest that AF burden, and associated risk, s not stable over time.

Association of Atrial Fibrillation Burden and Mortality Among Patients With Cardiac Implantable Electronic Devices

BACKGROUND

Current estimates of atrial fibrillation (AF)-associated mortality rely on claims- or clinical-derived diagnoses of AF, limit AF to a binary entity, or are confounded by comorbidities. The objective of the present study is to assess the association between device-recognized AF and mortality among patients with cardiac implantable electronic devices capable of sensitive and continuous atrial arrhythmia detection. Secondary outcomes include relative mortality among cohorts with no AF, paroxysmal AF, persistent AF, and permanent AF.

METHODS

Using the deidentified Optum Clinformatics US claims database (2015 to 2020) linked to the Medtronic CareLink database, we identified individuals with a cardiac implantable electronic device who transmitted data ≥6 months after implantation. AF burden was assessed during the first 6 months after implantation (baseline period). Subsequent mortality, assessed from claims data, was compared between patients with and without AF, with adjustment for age, geographic region, insurance type, Charlson Comorbidity Index, and implantation year.

RESULTS

Of 21 391 patients (age, 72.9±10.9 years; 56.3% male) analyzed, 7798 (36.5%) had device-recognized AF. During a mean of 22.4±12.9 months (median, 20.1 [12.8-29.7] months) of follow-up, the overall incidence of mortality was 13.5%. Patients with AF had higher adjusted all-cause mortality than patients without AF (hazard ratio, 1.29 [95% CI, 1.20-1.39]; P<0.001). Among those with AF, patients with nonparoxysmal AF had the greatest risk of mortality (persistent AF versus paroxysmal AF: hazard ratio, 1.36 [95% CI, 1.18-1.58]; P<.001; permanent AF versus paroxysmal AF: hazard ratio, 1.23 [95% CI, 1.14-1.34]; P<.001).

CONCLUSIONS

After adjustment for potential confounding factors, the presence of AF was associated with higher mortality in our cohort of patients with cardiac implantable electronic devices. Among those with AF, nonparoxysmal AF was associated with the greatest risk of mortality.

Controversies in Diagnosis and Management of Atrial Fibrillation

Early detection of atrial fibrillation (AF) plays an important role in decreasing adverse cardiovascular outcomes. It is estimated, however, that one-third of those with AF are asymptomatic and may experience the adverse effects of the arrhythmia prior to being detected clinically. In the past, AF was diagnosed on 12-lead electrocardiogram or medically prescribed external monitors. The development of device-monitoring technologies capable of recording AF or AF-surrogates such as atrial high-rate episodes on cardiovascular implantable electronic devices or photoplethysmography/electrocardiogram on consumer-grade wearable devices, has resulted in increased recognition of device-detected, subclinical, AF. Recent studies reveal information about the stroke risk associated with these subclinical events and the response to anticoagulation and raise important questions about the use of both medical and direct-to-consumer AF detection devices for screening purposes. In addition to screening and detection of AF, emerging studies are also being conducted on different strategies for maintenance of sinus rhythm and stroke prevention including catheter ablation and left atrial appendage occlusion. This review aims to highlight recent developments and future studies in these areas.

Direct oral anticoagulants for stroke prevention in patients with device-detected atrial fibrillation: assessing net clinical benefit

Subclinical, device-detected atrial fibrillation (AF) is frequently recorded by pacemakers and other implanted cardiac rhythm devices. Patients with device-detected AF have an elevated risk of stroke, but a lower risk of stroke than similar patients with clinical AF captured with surface electrocardiogram. Two randomized clinical trials (NOAH-AFNET 6 and ARTESiA) have tested a direct oral anticoagulant (DOAC) against aspirin or placebo. A study-level meta-analysis of the two trials found that treatment with a DOAC resulted in a 32% reduction in ischaemic stroke and a 62% increase in major bleeding; the results of the two trials were consistent. The annualized rate of stroke in the control arms was ∼1%. Several factors point towards overall net benefit from DOAC treatment for patients with device-detected AF. Strokes in ARTESiA were frequently fatal or disabling and bleeds were rarely lethal. The higher absolute rates of major bleeding compared with ischaemic stroke while on treatment with a DOAC in the two trials are consistent with the ratio of bleeds to strokes seen in the pivotal DOAC vs. warfarin trials in patients with clinical AF. Prior research has concluded that patients place a higher emphasis on stroke prevention than on bleeding. Further research is needed to identify the characteristics that will help identify patients with device-detected AF who will receive the greatest benefit from DOAC treatment.

Comparison of Cryoballoon vs. Pulsed Field Ablation in Patients with Symptomatic Paroxysmal Atrial Fibrillation (SINGLE SHOT CHAMPION): Study protocol for a randomized controlled trial

Background

Single-shot devices are increasingly used for pulmonary vein isolation (PVI) in atrial fibrillation (AF). The Arctic Front cryoballoon is the most frequently used single-shot technology. A recently developed novel pulsed field ablation (PFA) device (FARAPULSE) has been introduced with the aim to improve procedural safety and efficacy.

Objective

This study will compare the novel FARAPULSE PFA device and the Arctic Front cryoballoon for first PVI in patients with symptomatic paroxysmal AF.

Methods

SINGLE SHOT CHAMPION is a multicenter, randomized controlled trial with blinded endpoint adjudication by an independent clinical events committee. Overall, 210 patients with paroxysmal AF undergoing their PVI are randomized 1:1 between PFA and cryoballoon ablation. Continuous rhythm monitoring with an implantable cardiac monitor is performed in all patients.

Results

The primary endpoint is time to first recurrence of any atrial tachyarrhythmia (AF and/or organized atrial tachyarrhythmia) lasting ≥120 seconds and identified by the implantable cardiac monitor within 91 and 365 days postablation. The composite procedural safety endpoint includes cardiac tamponade requiring drainage, persistent phrenic nerve palsy, vascular complications requiring intervention, stroke/transient ischemic attack, atrioesophageal fistula, and death occurring during or up to 30 days after the procedure. Key secondary endpoints include (1) increase in high-sensitivity troponin on day 1 postablation, (2) analysis of postablation 3-dimensional electroanatomic mapping (first 25 patients per study group), (3) AF burden, and (4) quality-of-life changes.

Conclusion

SINGLE SHOT CHAMPION will evaluate the efficacy and safety of PVI using the novel FARAPULSE PFA for patients with symptomatic paroxysmal AF.

The Incidence of Atrial Fibrillation After Percutaneous Patent Foramen Ovale Closure Detected by Implantable Loop Recorders

Background

Patent foramen ovale (PFO) is seen in 25% of the general population but in up to 50% of patients ≤60 years old with cryptogenic strokes. Trials have shown that PFO closure vs medical therapy reduces the risk of future strokes. PFO closure may cause atrial fibrillation (AF), with prior trials reporting an incidence of 2% to 11.9%. However, the true incidence of AF after PFO closure is unknown due to limitations in prior studies for long-term monitoring.

Methods

This is a retrospective observational study at a single center. Patients who underwent PFO closure and had an implantable loop recorder prior to PFO closure were included. The final review included 38 patients who had at least 2 months of implantable loop recorder data post-PFO closure.

Results

Ten out of 38 (26%) patients developed AF post-PFO closure. The median time to the first episode of AF was 3.95 weeks, with 40% having their first AF episode after 3 months. Median duration of AF episodes was 1 hour. One hundred percent had spontaneous termination of AF. Of the AF patients, 70% were started on oral anticoagulant therapy.

Conclusions

Our review shows a higher incidence of AF post-PFO closure as compared with most reported prior studies. We recommend larger prospective studies to explore the true incidence of AF post-PFO closure, its clinical impact, and subsequent stroke risk.

Potential Role of Left Atrial Strain to Predict Atrial Fibrillation Recurrence after Catheter Ablation Therapy: A Clinical and Systematic Review

Pulmonary vein isolation (PVI) with catheter ablation (CA) represents an effective therapy for atrial fibrillation (AF). Unfortunately, it is still not exempt from severe complications. The balance of risks and benefits should be assessed, and a patient-tailored approach is desirable. So far, several clinical and cardiac imaging parameters have been evaluated to investigate pre- and post-procedural features that could help clinicians in the selection of patients at high risk of a poor outcome after CA. This clinical and systematic review analyses the potential role of new LA parameters, such as LA reservoir strain, to predict AF recurrence after CA therapy. Notably, LA reservoir strain gains substantial clinical importance in patients with paroxysmal AF and when a low CHADS2-VASc score is retrieved. LA reservoir strain provides data concerning the risk of AF recurrence after PVI and, thus, in the management of long-term medical therapy in this patient's group.

Observational study protocol for an arrhythmia notification feature

INTRODUCTION

Screening for atrial fibrillation (AF) in the general population may help identify individuals at risk, enabling further assessment of risk factors and institution of appropriate treatment. Algorithms deployed on wearable technologies such as smartwatches and fitness bands may be trained to screen for such arrhythmias. However, their performance needs to be assessed for safety and accuracy prior to wide-scale implementation.

METHODS AND ANALYSIS

This study will assess the ability of the WHOOP strap to detect AF using its WHOOP Arrhythmia Notification Feature (WARN) algorithm in an enriched cohort with a 2:1 distribution of previously diagnosed AF (persistent and paroxysmal) and healthy controls. Recruited participants will collect data for 7 days with the WHOOP wrist-strap and BioTel ePatch (electrocardiography gold-standard). Primary outcome will be participant level sensitivity and specificity of the WARN algorithm in detecting AF in analysable windows compared with the ECG gold-standard. Similar analyses will be performed on an available epoch-level basis as well as comparison of these findings in important subgroups.

ETHICS AND DISSEMINATION

The study was approved by the ethics board at the study site. Participants will be enrolled after signing an online informed consent document. Updates will be shared via clinicaltrials.gov. The data obtained from the conclusion of this study will be presented in national and international conferences with publication in clinical research journals.

TRIAL REGISTRATION NUMBER

NCT05809362.

[Characterization of atrial fibrillation burden using wearables]

The characterization of atrial fibrillation (AF) according to current guidelines categorically refers to the differentiation between paroxysmal, persistent, and permanent AF. A more precise characterization of AF, including the evaluation of AF burden, is playing an increasingly significant role in both scientific research and clinical practice. Digital devices, especially those with the capability of passive (semi-)continuous recording, can contribute to a more accurate quantification of AF burden. Particularly in patients with an already established diagnosis of AF, the evaluation of AF burden can be used to monitor the success of antiarrhythmic therapy including antiarrhythmic drugs or pulmonary vein isolation. However, important questions remain unanswered: In addition to a uniform, evidence-based definition of AF burden, clinically relevant cut-offs for AF burden and resulting therapeutic consequences (e.g., subclinical AF) need to be elaborated. Furthermore, the establishment and evaluation of care structures for assessing and integrating AF burden in clinical care, especially by incorporating data from wearable medical devices, should take place.

Toward More Personalized Management of Device-Detected Atrial Fibrillation

This Viewpoint discusses the need to individualize the management of subclinical atrial fibrillation according to burden (among other factors) by modeling stroke risk.

Metformin reduces new-onset atrial fibrillation risk rather than atrial fibrillation burden in type 2 diabetes patients: A case-control study

Background

The effects of metformin on atrial fibrillation (AF) in type 2 diabetes patients remain unclear. We aimed to explore the effects of metformin on AF, including new-onset AF and AF burden, in type 2 diabetes patients with pacemakers.

Methods and results

This retrospective study included a total of 227 patients. Based on the presence of paroxysmal AF, the patients were divided into a paroxysmal AF group (n = 80) and a non-AF group (n = 147). In the non-AF group, a significant association was observed between metformin use and a lower risk of new-onset AF in multivariable Cox hazards models (hazard ratio [HR]: 0.36; 95 % confidence interval [CI]: 0.14-0.91; p = 0.0311*) when adjusted for age, sex, body mass index (BMI), drinking, smoking, left atrial dimension, creatinine, complications, and drugs. In the paroxysmal AF group, univariable analysis indicated no association between the AF burden and metformin use (p = 0.817). Furthermore, when adjusted for metformin use, age, sex, BMI, drinking, smoking, cardiovascular disease, myocardial infarction, heart failure, stroke, and ejection fraction in multivariable Cox hazards models, we found a lower proportion of major adverse cardiovascular events (MACEs) both in the total (HR: 0.28; 95 % CI: 0.1-0.82; p = 0.0202*) and the non-AF group (HR: 0.19; 95 % CI: 0.05-0.79; p = 0.0223*) compared to that in the AF group (HR: 0.31; 95 % CI: 0.02-4.41; p = 0.3879).

Conclusion

In type 2 diabetes patients with pacemakers, metformin reduced the probability of new-onset AF instead of addressing the AF burden. Furthermore, metformin therapy decreased the incidence of MACEs in type 2 diabetes patients without AF.

Comprehensive atrial fibrillation burden and symptom reduction post-ablation: insights from DECAAF II

AIMS

Traditional atrial fibrillation (AF) recurrence after catheter ablation is reported as a binary outcome. However, a paradigm shift towards a more granular definition, considering arrhythmic or symptomatic burden, is emerging. We hypothesize that ablation reduces AF burden independently of conventional recurrence status in patients with persistent AF, correlating with symptom burden reduction.

METHODS AND RESULTS

Ninety-eight patients with persistent AF from the DECAAF II trial with pre-ablation follow-up were included. Patients recorded daily single-lead electrocardiogram (ECG) strips, defining AF burden as the proportion of AF days among total submitted ECG days. The primary outcome was atrial arrhythmia recurrence. The AF severity scale was administered pre-ablation and at 12 months post-ablation. At follow-up, 69 patients had atrial arrhythmia recurrence and 29 remained in sinus rhythm. These patients were categorized into a recurrence (n = 69) and a no-recurrence group (n = 29). Both groups had similar baseline characteristics, but recurrence patients were older (P = 0.005), had a higher prevalence of hyperlipidaemia (P = 0.007), and had a larger left atrial (LA) volume (P = 0.01). There was a reduction in AF burden in the recurrence group when compared with their pre-ablation burden (65 vs. 15%, P < 0.0001). Utah Stage 4 fibrosis and diabetes predicted less improvement in AF burden. The symptom severity score at 12 months post-ablation was significantly reduced compared with the pre-ablation score in the recurrence group, and there was a significant correlation between the reduction in symptom severity score and the reduction in AF burden (R = 0.39, P = 0.001).

CONCLUSION

Catheter ablation reduces AF burden, irrespective of arrhythmia recurrence post-procedure. There is a strong correlation between AF burden reduction and symptom improvement post-ablation. Notably, elevated LA fibrosis impedes AF burden decrease following catheter ablation.

Photoplethysmography based atrial fibrillation detection: a continually growing field

Objective. Atrial fibrillation (AF) is a prevalent cardiac arrhythmia associated with significant health ramifications, including an elevated susceptibility to ischemic stroke, heart disease, and heightened mortality. Photoplethysmography (PPG) has emerged as a promising technology for continuous AF monitoring for its cost-effectiveness and widespread integration into wearable devices. Our team previously conducted an exhaustive review on PPG-based AF detection before June 2019. However, since then, more advanced technologies have emerged in this field.Approach. This paper offers a comprehensive review of the latest advancements in PPG-based AF detection, utilizing digital health and artificial intelligence (AI) solutions, within the timeframe spanning from July 2019 to December 2022. Through extensive exploration of scientific databases, we have identified 57 pertinent studies.Significance. Our comprehensive review encompasses an in-depth assessment of the statistical methodologies, traditional machine learning techniques, and deep learning approaches employed in these studies. In addition, we address the challenges encountered in the domain of PPG-based AF detection. Furthermore, we maintain a dedicated website to curate the latest research in this area, with regular updates on a regular basis.

Higher Frequency of Premature Atrial Contractions Correlates With Atrial Fibrillation Detection after Cryptogenic Stroke

BACKGROUND

Covert atrial fibrillation (AF) is a major cause of cryptogenic stroke. This study investigated whether a dose-dependent relationship exists between the frequency of premature atrial contractions (PACs) and AF detection in patients with cryptogenic stroke using an insertable cardiac monitor (ICM).

METHODS

We enrolled consecutive patients with cryptogenic stroke who underwent ICM implantation between October 2016 and September 2020 at 8 stroke centers in Japan. Patients were divided into 3 groups according to the PAC count on 24-hour Holter ECG: ≤200 (group L), >200 to ≤500 (group M), and >500 (group H). We defined a high AF burden as above the median of the cumulative duration of AF episodes during the entire monitoring period. We evaluated the association of the frequency of PACs with AF detection using log-rank trend test and Cox proportional hazard model and with high AF burden using logistic regression model, adjusting for age, sex, CHADS2 score.

RESULTS

Of 417 patients, we analyzed 381 patients with Holter ECG and ICM data. The median age was 70 (interquartile range, 59.5-76.5), 246 patients (65%) were males, and the median duration of ICM recording was 605 days (interquartile range, 397-827 days). The rate of new AF detected by ICM was higher in groups with more frequent PAC (15.5%/y in group L [n=277] versus 44.0%/y in group M [n=42] versus 71.4%/y in group H [n=62]; log-rank trend P<0.01). Compared with group L, the adjusted hazard ratios for AF detection in groups M and H were 2.11 (95% CI, 1.24-3.58) and 3.23 (95% CI, 2.07-5.04), respectively, and the adjusted odds ratio for high AF burden in groups M and H were 2.57 (95% CI, 1.14-5.74) and 4.25 (2.14-8.47), respectively.

CONCLUSIONS

The frequency of PACs was dose-dependently associated with AF detection in patients with cryptogenic stroke.

Impact of Atrial Fibrillation Burden on Health Care Costs and Utilization

BACKGROUND

Integrating patient-specific cardiac implantable electronic device (CIED)-detected atrial fibrillation (AF) burden with measures of health care cost and utilization allows for an accurate assessment of the AF-related impact on health care use.

OBJECTIVES

The goal of this study was to assess the incremental cost of device-recognized AF vs no AF; compare relative costs of paroxysmal atrial fibrillation (pAF), persistent atrial fibrillation (PeAF), and permanent atrial fibrillation (PermAF) AF; and evaluate rates and sources of health care utilization between cohorts.

METHODS

Using the de-identified Optum Clinformatics U.S. claims database (2015-2020) linked with the Medtronic CareLink database, CIED patients were identified who transmitted data ≥6 months postimplantation. Annualized per-patient costs in follow-up were analyzed from insurance claims and adjusted to 2020 U.S. dollars. Costs and rates of health care utilization were compared between patients with no AF and those with device-recognized pAF, PeAF, and PermAF. Analyses were adjusted for geographical region, insurance type, CHA2DS2-VASc score, and implantation year.

RESULTS

Of 21,391 patients (mean age 72.9 ± 10.9 years; 56.3% male) analyzed, 7,798 (36.5%) had device-recognized AF. The incremental annualized increased cost in those with AF was $12,789 ± $161,749 per patient, driven by increased rates of health care encounters, adverse clinical events associated with AF, and AF-specific interventions. Among those with AF, PeAF was associated with the highest cost, driven by increased rates of inpatient and outpatient hospitalization encounters, heart failure hospitalizations, and AF-specific interventions.

CONCLUSIONS

Presence of device-recognized AF was associated with increased health care cost. Among those with AF, patients with PeAF had the highest health care costs. Mechanisms for cost differentials include both disease-specific consequences and physician-directed interventions.

Evaluation of an algorithm-guided photoplethysmography for atrial fibrillation burden using a smartwatch

BACKGROUND

Wearable devices based on the PPG algorithm can detect atrial fibrillation (AF) effectively. However, further investigation of its application on long-term, continuous monitoring of AF burden is warranted.

METHOD

The performance of a smartwatch with continuous photoplethysmography (PPG) and PPG-based algorithms for AF burden estimation was evaluated in a prospective study enrolling AF patients admitted to Beijing Anzhen Hospital for catheter ablation from September to November 2022. A continuous Electrocardiograph patch (ECG) was used as the reference device to validate algorithm performance for AF detection in 30-s intervals.

RESULTS

A total of 578669 non-overlapping 30-s intervals for PPG and ECG each from 245 eligible patients were generated. An interval-level sensitivity of PPG was 96.3% (95% CI 96.2%-96.4%), and specificity was 99.5% (95% CI 99.5%-99.6%) for the estimation of AF burden. AF burden estimation by PPG was highly correlated with AF burden calculated by ECG via Pearson correlation coefficient (R2 = 0.996) with a mean difference of -0.59 (95% limits of agreement, -7.9% to 6.7%). The subgroup study showed the robust performance of the algorithm in different subgroups, including heart rate and different hours of the day.

CONCLUSION

Our results showed the smartwatch with an algorithm-based PPG monitor has good accuracy and stability in continuously monitoring AF burden compared with ECG patch monitors, indicating its potential for diagnosing and managing AF.

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.

Anticoagulation with edoxaban in patients with long atrial high-rate episodes ≥24 h

BACKGROUND AND AIMS

Patients with long atrial high-rate episodes (AHREs) ≥24 h and stroke risk factors are often treated with anticoagulation for stroke prevention. Anticoagulation has never been compared with no anticoagulation in these patients.

METHODS

This secondary pre-specified analysis of the Non-vitamin K antagonist Oral anticoagulants in patients with Atrial High-rate episodes (NOAH-AFNET 6) trial examined interactions between AHRE duration at baseline and anticoagulation with edoxaban compared with placebo in patients with AHRE and stroke risk factors. The primary efficacy outcome was a composite of stroke, systemic embolism, or cardiovascular death. The safety outcome was a composite of major bleeding and death. Key secondary outcomes were components of these outcomes and electrocardiogram (ECG)-diagnosed atrial fibrillation.

RESULTS

Median follow-up of 2389 patients with core lab-verified AHRE was 1.8 years. AHRE ≥24 h were present at baseline in 259/2389 patients (11%, 78 ± 7 years old, 28% women, CHA2DS2-VASc 4). Clinical characteristics were not different from patients with shorter AHRE. The primary outcome occurred in 9/132 patients with AHRE ≥24 h (4.3%/patient-year, 2 strokes) treated with anticoagulation and in 14/127 patients treated with placebo (6.9%/patient-year, 2 strokes). Atrial high-rate episode duration did not interact with the efficacy (P-interaction = .65) or safety (P-interaction = .98) of anticoagulation. Analyses including AHRE as a continuous parameter confirmed this. Patients with AHRE ≥24 h developed more ECG-diagnosed atrial fibrillation (17.0%/patient-year) than patients with shorter AHRE (8.2%/patient-year; P < .001).

CONCLUSIONS

This hypothesis-generating analysis does not find an interaction between AHRE duration and anticoagulation therapy in patients with device-detected AHRE and stroke risk factors. Further research is needed to identify patients with long AHRE at high stroke risk.

Prognostic implication of early recurrence after cryoballoon ablation in patients with atrial fibrillation

BACKGROUND

It remains uncertain whether the implication of early recurrence and blanking period can be applied to patients with atrial fibrillation (AF) treated with cryoballoon ablation (CBA). We aimed to explore the prognostic value of early recurrence in patients with AF treated with CBA.

METHODS

We studied consecutive AF patients who were treated with CBA between April 2019 and September 2020 in two tertiary medical institutes and followed for up to 12 months. The endpoint was the late recurrence of atrial arrhythmia, including AF, atrial flutter, and atrial tachycardia, following a 90-day blanking period. Atrial arrhythmia during the blanking period was defined as early recurrence and was not considered as an endpoint.

RESULTS

This study included 406 patients with AF who underwent CBA. During the follow-up, 147 (36.2%) cases of late recurrence were observed. Of the 104 patients with early recurrence, 85 experienced late recurrence during follow-up. Early recurrence was associated with an increased risk of late recurrence in the univariate and multivariate analyses (P < 0.001). When we classified the patients into paroxysmal AF and persistent AF groups, early recurrence was still significantly associated with a higher risk of late recurrence (P = 0.005 and P < 0.001, respectively).

CONCLUSION

Early recurrence after CBA was an independent risk factor for late recurrence in all patients as well as in those with paroxysmal AF and persistent AF. Therefore, further prospective studies could be considered to verify the risks and benefits of early rhythm control in patients with early recurrence.

Kidney Function, Albuminuria, and Risk of Incident Atrial Fibrillation: A Systematic Review and Meta-Analysis

RATIONALE & OBJECTIVE

Atrial fibrillation (AF) and chronic kidney disease (CKD) often coexist. However, it is not known whether CKD is an independent risk factor for incident AF. Therefore, we evaluated the association between markers of CKD-estimated glomerular filtration rate (eGFR) and albuminuria-and incident AF.

STUDY DESIGN

Systematic review and meta-analysis of cohort studies and randomized controlled trials.

SETTING & STUDY POPULATIONS

Participants with measurement of eGFR and/or albuminuria who were not receiving dialysis.

SELECTION CRITERIA FOR STUDIES

Cohort studies and randomized controlled trials were included that reported incident AF risk in adults according to eGFR and/or albuminuria.

ANALYTICAL APPROACH

Age- or multivariate-adjusted risk ratios (RRs) for incident AF were extracted from cohort studies, and RRs for each trial were derived from event data. RRs for incident AF were pooled using random-effects models.

RESULTS

38 studies involving 28,470,249 participants with 530,041 incident AF cases were included. Adjusted risk of incident AF was greater among participants with lower eGFR than those with higher eGFR (eGFR<60 vs≥60mL/min/1.73m2: RR, 1.43; 95% CI, 1.30-1.57; and eGFR<90 vs≥90mL/min/1.73m2: RR, 1.42; 95% CI, 1.26-1.60). Adjusted incident AF risk was greater among participants with albuminuria (any albuminuria vs no albuminuria: RR, 1.43; 95% CI, 1.25-1.63; and moderately to severely increased albuminuria vs normal to mildly increased albuminuria: RR, 1.64; 95% CI, 1.31-2.06). Subgroup analyses showed an exposure-dependent association between CKD and incident AF, with the risk increasing progressively at lower eGFR and higher albuminuria categories.

LIMITATIONS

Lack of patient-level data, interaction between eGFR and albuminuria could not be evaluated, possible ascertainment bias due to variation in the methods of AF detection.

CONCLUSIONS

Lower eGFR and greater albuminuria were independently associated with increased risk of incident AF. CKD should be regarded as an independent risk factor for incident AF.

PLAIN-LANGUAGE SUMMARY

Irregular heartbeat, or atrial fibrillation (AF), is the commonest abnormal heart rhythm. AF occurs commonly in people with chronic kidney disease (CKD), and CKD is also common in people with AF. However, CKD in not widely recognized as a risk factor for new-onset or incident AF. In this research, we combined data on more than 28 million participants in 38 studies to determine whether CKD itself increases the chances of incident AF. We found that both commonly used markers of kidney disease (estimated glomerular filtration rate and albuminuria, ie, protein in the urine) were independently associated with a greater risk of incident AF. This finding suggests that CKD should be recognized as an independent risk factor for incident AF.

Catheter ablation versus medical therapy in atrial fibrillation: an umbrella review of meta-analyses of randomized clinical trials

This umbrella review synthesizes data from 17 meta-analyses investigating the comparative outcomes of catheter ablation (CA) and medical treatment (MT) for atrial fibrillation (AF). Outcomes assessed were mortality, risk of hospitalization, AF recurrence, cardiovascular events, pulmonary vein stenosis, major bleeding, and changes in left ventricular ejection fraction (LVEF) and MLHFQ score. The findings indicate that CA significantly reduces overall mortality and cardiovascular hospitalization with high strength of evidence. The risk of AF recurrence was notably lower with CA, with moderate strength of evidence. Two associations reported an increased risk of pulmonary vein stenosis and major bleeding with CA, supported by high strength of evidence. Improved LVEF and a positive change in MLHFQ were also associated with CA. Among patients with AF and heart failure, CA appears superior to MT for reducing mortality, improving LVEF, and reducing cardiovascular rehospitalizations. In nonspecific populations, CA reduced mortality and improved LVEF but had higher complication rates. Our findings suggest that CA might offer significant benefits in managing AF, particularly in patients with heart failure. However, the risk of complications, including pulmonary vein stenosis and major bleeding, is notable. Further research in understudied populations may help refine these conclusions.

Sex-based differences in obstructive sleep apnea and atrial fibrillation: Implication of atrial fibrillation burden

Background

Obstructive sleep apnea (OSA) is a risk factor for atrial fibrillation (AF); however, it is unclear whether AF increases the risk of OSA. Furthermore, sex differences among patients with both AF and OSA remain unclear. We aimed to determine the association between an increased AF burden and OSA and investigate the differences in clinical characteristics between women and men with AF and OSA.

Methods

This was a descriptive, cross-sectional analysis from a prospective cohort study. Patients with non-valvular AF were recruited from the cardiac electrophysiology clinic of a tertiary center; they underwent a home sleep apnea test and 14-day ambulatory electrocardiography. Moderate-to-severe OSA was defined as an apnea-hypopnea index of ≥15.

Results

Of 320 patients with AF, 53.4% had moderate-to-severe OSA, and the mean body mass index (BMI) was 25.6 kg/m2. Less women (38.2%) had moderate-to-severe OSA than men (59.3%) (p < 0.001). In the multivariate analysis, age, being a man, and BMI were significantly associated with moderate-to-severe OSA. AF burden was associated with moderate-to-severe OSA only in men (odds ratio: 1.008; 95% confidence interval: 1.001-1.014). Women and men with OSA had similar BMI (p = 0.526) and OSA severity (p = 0.754), but women were older than men (70.1 ± 1.3 vs. 63.1 ± 0.9 years, p < 0.001). Women with moderate-to-severe OSA had a lower AF burden than men did (27.6 ± 7.1 vs. 49.5 ± 3.9%, p = 0.009).

Conclusions

AF burden is a sex-specific risk factor for OSA and is limited to men. In contrast, women with both AF and OSA have a lower AF burden than men, despite being older and having similar OSA severity and body habitus. Thus, AF may develop later in women with OSA than in men.

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

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

Combined use of anticoagulant and antiplatelet on outcome after stroke in patients with nonvalvular atrial fibrillation and systemic atherosclerosis

This study aimed to investigate whether there was a difference in one-year outcome after stroke between patients treated with antiplatelet and anticoagulation (OAC + antiplatelet) and those with anticoagulation only (OAC), when comorbid atherosclerotic disease was present with non-valvular atrial fibrillation (NVAF). This was a retrospective study using a prospective cohort of consecutive patients with ischemic stroke. Patients with NVAF and comorbid atherosclerotic disease were assigned to the OAC + antiplatelet or OAC group based on discharge medication. All-cause mortality, recurrent ischemic stroke, hemorrhagic stroke, myocardial infarction, and bleeding events within 1 year after the index stroke were compared. Of the 445 patients included in this study, 149 (33.5%) were treated with OAC + antiplatelet. There were no significant differences in all outcomes between groups. After inverse probability of treatment weighting, OAC + antiplatelet was associated with a lower risk of all-cause mortality (hazard ratio 0.48; 95% confidence interval 0.23-0.98; P = 0.045) and myocardial infarction (0% vs. 3.0%, P < 0.001). The risk of hemorrhagic stroke was not significantly different (P = 0.123). OAC + antiplatelet was associated with a decreased risk of all-cause mortality and myocardial infarction but an increased risk of ischemic stroke among patients with NVAF and systemic atherosclerotic diseases.

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.

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.

Automatic segmentation of atrial fibrillation and flutter in single-lead electrocardiograms by self-supervised learning and Transformer architecture

OBJECTIVES

Automatic detection of atrial fibrillation and flutter (AF/AFL) is a significant concern in preventing stroke and mitigating hemodynamic instability. Herein, we developed a Transformer-based deep learning model for AF/AFL segmentation in single-lead electrocardiograms (ECGs) by self-supervised learning with masked signal modeling (MSM).

MATERIALS AND METHODS

We retrieved data from 11 open-source databases on PhysioNet; 7 of these databases included labeled ECGs, while the other 4 were without labels. Each database contained ECG recordings with durations of ≥30 s. A total of 24 intradialytic ECGs with paroxysmal AF/AFL during 4 h of hemodialysis sessions at Seoul National University Hospital were used for external validation. The model was pretrained by predicting masked areas of ECG signals and fine-tuned by predicting AF/AFL areas. Cross-database validation was used for evaluation, and the intersection over union (IOU) was used as a main performance metric in external database validation.

RESULTS

In the 7 labeled databases, the areas marked as AF/AFL constituted 41.1% of the total ECG signals, ranging from 0.19% to 51.31%. In the evaluation per ECG segment, the model achieved IOU values of 0.9254 and 0.9477 for AF/AFL segmentation and other segmentation tasks, respectively. When applied to intradialytic ECGs with paroxysmal AF/AFL, the IOUs for the segmentation of AF/AFL and non-AF/AFL were 0.9896 and 0.9650, respectively. Model performance by different training procedure indicated that pretraining with MSM and the application of an appropriate masking ratio both contributed to the model performance. It also showed higher IOUs of AF/AFL labels than in previous studies when training and test databases were matched.

CONCLUSION

The present model with self-supervised learning by MSM performs robustly in segmenting AF/AFL.

Impact of rs1805127 and rs55742440 Variants on Atrial Remodeling in Hypertrophic Cardiomyopathy Patients with Atrial Fibrillation: A Romanian Cohort Study

Atrial fibrillation (AFib) is characterized by a complex genetic component. We aimed to investigate the association between variations in genes related to cardiac ion handling and AFib in a cohort of Romanian patients with hypertrophic cardiomyopathy (HCM). Forty-five unrelated probands with HCM were genotyped by targeted next-generation sequencing (NGS) for 24 genes associated with cardiac ion homeostasis. Subsequently, the study cohort was divided into two groups based on the presence (AFib+) or absence (AFiB-) of AFib detected during ECG monitoring. We identified two polymorphisms (rs1805127 located in KCNE1 and rs55742440 located in SCN1B) linked to AFib susceptibility. In AFib+, rs1805127 was associated with increased indexed left atrial (LA) maximal volume (LAVmax) (58.42 ± 21 mL/m2 vs. 32.54 ± 6.47 mL/m2, p < 0.001) and impaired LA strain reservoir (LASr) (13.3 ± 7.5% vs. 24.4 ± 6.8%, p < 0.05) compared to those without respective variants. The rs55742440 allele was less frequent in patients with AFib+ (12 out of 25, 48%) compared to those without arrhythmia (15 out of 20, 75%, p = 0.05). Also, AFib+ rs55742440 carriers had significantly lower LAVmax compared to those who were genotype negative. Among patients with HCM and AFib+, the rs1805127 variant was accompanied by pronounced LA remodeling, whereas rs55742440's presence was related to a milder LA enlargement.

Catheter Ablation of Persistent AF-Where are We Now?

Persistent atrial fibrillation (AF) is a diverse condition that includes various subtypes and underlying causes of arrhythmia. Progress made in catheter ablation technology in recent years has significantly enhanced the durability of ablation. Despite these advances however, the effectiveness of ablation in treating persistent AF is still relatively modest. Studies exploring the mechanisms behind persistent AF have identified substrate-driven focal and re-entrant sources within the atrial body as crucial in sustaining AF among individuals with persistent AF. Furthermore, the widespread adoption of atrial late gadolinium enhancement cardiac magnetic resonance (CMR) imaging and the ongoing refinement of invasive voltage mapping techniques have allowed for detailed assessment of fibrotic remodelling prior to or at the time of procedure. Translation into clinical practice, however, has yielded overall disappointing results. The clinical application of AF mapping in ablation procedures has not shown any substantial advantages beyond the use of pulmonary vein isolation (PVI) alone and adjunct ablation of fibrotic areas has yielded conflicting results in recent randomized trials. The emergence of pulsed field ablation represents a welcome development in the field and several studies have demonstrated an enhanced safety profile and increased procedural efficiency with this non-thermal energy modality. Pulsed field ablation also holds promise for safe and efficient substrate ablation beyond the pulmonary veins, but further trials are needed to assess its impact on longer term success rates. Continued advancements in our comprehension of AF mechanisms, alongside ongoing developments in catheter technology aimed at safe formation of transmural lesions, are essential for achieving better clinical outcomes for patients with persistent AF.

Ambulatory Electrocardiography Monitoring for Early Discharge After Minimally Invasive Valve Surgery

INTRODUCTION

We sought to compare outcomes after early discharge in patients with and without predischarge diagnosis of arrhythmia following minimally invasive valve surgery (MIVS).

MATERIALS AND METHODS

We retrospectively reviewed ambulatory electrocardiography (AECG) datasheets and medical records of patients discharged with 14-d AECG monitoring from our facility between October 2019 and March 2022 ≤ 3 d after MIVS. Baseline and clinical characteristics, arrhythmias during AECG monitoring, and 30-d adverse outcomes were reported for the population and stratified by presence or absence of predischarge arrhythmia.

RESULTS

Of 41 patients discharged ≤3 d postoperatively of MIVS, 17 (41.5%) experienced predischarge arrhythmias and 24 (58.5%) did not. The population was predominantly male and White with a median age of 62 y [57, 70]. Baseline and clinical characteristics did not differ between subgroups. Most patients (92.7% [n = 38]) experienced one or more tachyarrhythmias during the AECG monitoring period. There were similar proportions of patients experiencing atrial fibrillation in both groups, but patients with predischarge arrhythmias had higher burden of atrial fibrillation on AECG monitoring (27.60% [6.57%, 100%] versus 1.65% [0.76%, 4.32%]; P = 0.004). The predischarge arrhythmia subgroup had higher proportions of patients experiencing nonsustained ventricular tachycardia but lower proportions experiencing supraventricular tachycardia. There were no mortalities within 30 d of surgery. Six (14.6%) patients were readmitted within 30 d with equal proportions of readmissions between subgroups (P = 0.662).

CONCLUSIONS

Early discharge timelines and noninvasive monitoring techniques can allow patients to return to their normal activities quicker in the comfort of their own home with no increased risk of morbidity or mortality.

[Long-term success after catheter ablation of atrial fibrillation]

Ablation is an established treatment option for atrial fibrillation (AF) and is associated with convincing success rates and a reasonable safety profile. Ablation strategies going beyond pulmonary vein isolation in patients with chronic forms of AF are less well established and reproducible. Especially in patients with progressed AF forms multiple ablation procedures might be mandatory to achieve reasonable clinical success. An early ablation strategy might stop or prolong the progress from paroxysmal to persistent AF. In addition, ablation is more effective than drug-based treatment and comparably safe. Long-term success rates after a single and after multiple ablation procedures in paroxysmal AF are reported with 60-70% and up to 80%, while success rates in persistent or long-standing persistent AF are less favorable (single procedure 40-50%, multiple procedures 70%). However, currently non-recurrence of AF is the most established but potentially not the best endpoint. The burden of AF after ablation as assessed by novel monitoring modalities might gain further clinical importance.

Risk Factors for the Development of New-Onset Persistent Atrial Fibrillation: Subanalysis of the VITAL Study

BACKGROUND

Sustained forms of atrial fibrillation (AF) are associated with lower treatment success rates and poorer prognosis compared with paroxysmal AF. Yet, little is known about risk factors that predispose to persistent AF on initial presentation. Our objective was to define risk factors associated with new-onset persistent AF.

METHODS

We prospectively examined the differential associations between lifestyle, clinical, and socioeconomic risk factors and AF pattern (persistent versus paroxysmal) at the time of diagnosis among 25 119 participants without a history of cardiovascular disease, AF, or cancer in the VITAL rhythm study (Vitamin D and Omega-3).

RESULTS

During a median follow-up of 5.3 years, 900 participants developed AF and 346 (38.4%) were classified as persistent at the time of diagnosis. In multivariable competing risk models, increasing age, male sex, White race, height, weight, body mass index ≥30 kg/m2, hypertension, current or past smoking, alcohol intake ≥2 drinks/day, postcollege education, and randomized treatment with vitamin D were significantly associated with incident persistent AF. Compared with paroxysmal AF, increasing age, male sex, weight, body mass index ≥30 kg/m2, and postcollege education were more strongly associated with persistent AF in multivariable models regardless of whether interim cardiovascular disease and heart failure events were censored.

CONCLUSIONS

In a prospective cohort without baseline AF or cardiovascular disease, over one-third of AF at the time of diagnosis is persistent. Older age, male sex, postcollege education, and obesity were preferentially associated with persistent AF and represent a high-risk AF subset for population-based intervention.

Addressing racial differences in the management of atrial fibrillation: Focus on black patients

Atrial fibrillation (AF) is the most common sustained arrhythmia, affecting between 3 and 6 million people in the United States. It is associated with a reduced quality of life and increased risk of stroke, cognitive decline, heart failure and death. Black patients have a lower prevalence of AF than White patients but are more likely to suffer worse outcomes with the disease. It is important that stakeholders understand the disproportionate burden of disease and management gaps that exists among Black patients living with AF. Appropriate treatments, including aggressive risk factor control, early referral to cardiovascular specialists and improving healthcare access may bridge some of the gaps in management and improve outcomes.

Predictors of New Onset Atrial Fibrillation Burden in the Critically Ill

INTRODUCTION

Atrial fibrillation (AF) is common in the intensive care unit (ICU) setting and has been associated with adverse outcomes. In this context, there is increasing research interest in AF burden as a predictor of subsequent adverse events. However, the pathophysiology and drivers of AF burden in the ICU are poorly understood. This study sought to evaluate the predictors of AF burden in critical illness-associated new-onset AF (CI-NOAF).

METHODS

Out of 7,030 admissions in a tertiary general ICU between December 2015 and September 2018, 309 patients developed CI-NOAF. AF burden was defined as the percentage of monitored time in AF, as extracted from hourly interpretations of continuous ECG monitoring. Low and high AF burden groups were defined relative to the median AF burden. Clinical, laboratory, and echocardiographic parameters were extracted, and multivariable modelling with binary logistic regression was performed to evaluate for independent associations with AF burden.

RESULTS

The median AF burden was 7.0%. Factors associated with increased AF burden were age, dyslipidaemia, chronic kidney disease, increased creatinine, CHA2DS2-VASc score, ICU admission diagnosis category, amiodarone administration, and left atrial area (LAA). Factors associated with lower AF burden were previous alcohol excess, burden of ventilation, the use of inotropes/vasopressors, and beta blockers. On multivariate analysis, increased LAA, chronic kidney disease, and amiodarone use were independently associated with increased AF burden, whereas beta blocker use was associated with lower AF burden.

CONCLUSION

Left atrial size and chronic cardiovascular comorbidities appear to be the primary drivers of CI-NOAF burden, whereas factors related to acute illness and critical care intervention paradoxically did not appear to be a substantial driver of arrhythmia burden. Further research is needed regarding drivers of AF and the efficacy of rhythm control intervention in this unique setting.

Impact of Catheter Ablation on Arrhythmia Burden in Patients With Shock-Resistant Persistent Atrial Fibrillation

BACKGROUND

Persistent shock-resistant atrial fibrillation (AF) is a challenging entity, with modest results from catheter ablation according to conventional survival analysis.

OBJECTIVES

The aim of this study was to determine the effect of catheter ablation on atrial tachyarrhythmia (ATA) burden in persistent AF patients undergoing first-time ablation with the use of an implantable cardiac monitor (ICM).

METHODS

Patients with drug-resistant ongoing persistent AF and at least 1 previous failed cardioversion were implanted with an ICM 2 months before the procedure. All patients underwent pulmonary vein isolation with or without additional substrate ablation depending on the presence of self-terminating AF on ICM and left atrium size. Median AF burden before and after ablation, off antiarrhythmic medication, was determined from ICM recordings after review by 2 independent investigators.

RESULTS

Sixty patients were recruited (mean age 66 ± 9 years, 70% male). Mean left atrial diameter was 48 ± 6 mm and median CHA2DS2VASc score was 2. Ten patients (17%) unexpectedly demonstrated self-terminating AF before ablation. The median burden of ATA before ablation was 100% (95% CI: 19.6%-100%), decreasing to 0% (95% CI: 0%-95.8%) after ablation during the post-blanking follow-up period (median reduction 100%; 95% CI: 4%-100%; P < 0.001). Twenty-seven patients (45%) experienced recurrent ATA during 12-month follow-up. In these patients, median burden before ablation was 100% (95% CI: 26.9%-100%), decreasing to 11.4% (95% CI: 0.35%-99.7%) after ablation (P < 0.001). Quality of life improved significantly from baseline, driven by lack of recurrence.

CONCLUSIONS

Patient-tailored catheter ablation results in a significant reduction in ATA burden (off antiarrhythmic medication) in shock-resistant persistent AF patients using ICMs implanted 2-months pre-procedure. These data suggest that conventional arrhythmia-free survival analysis does not capture the true impact of catheter ablation in this challenging cohort.

Determine atrial fibrillation burden with a photoplethysmographic mobile sensor: the atrial fibrillation burden trial: detection and quantification of episodes of atrial fibrillation using a cloud analytics service connected to a wearable with photoplethysmographic sensor

Aims

Recent studies suggest that atrial fibrillation (AF) burden (time AF is present) is an independent risk factor for stroke. The aim of this trial was to study the feasibility and accuracy to identify AF episodes and quantify AF burden in patients with a known history of paroxysmal AF with a photoplethysmography (PPG)-based wearable.

Methods and results

In this prospective, single-centre trial, the PPG-based estimation of AF burden was compared with measurements of a conventional 48 h Holter electrocardiogram (ECG), which served as the gold standard. An automated algorithm performed PPG analysis, while a cardiologist, blinded for the PPG data, analysed the ECG data. Detected episodes of AF measured by both methods were aligned timewise.Out of 100 patients recruited, 8 had to be excluded due to technical issues. Data from 92 patients were analysed [55.4% male; age 73.3 years (standard deviation, SD: 10.4)]. Twenty-five patients presented AF during the study period. The intraclass correlation coefficient of total AF burden minutes detected by the two measurement methods was 0.88. The percentage of correctly identified AF burden over all patients was 85.1% and the respective parameter for non-AF time was 99.9%.

Conclusion

Our results demonstrate that a PPG-based wearable in combination with an analytical algorithm appears to be suitable for a semiquantitative estimation of AF burden in patients with a known history of paroxysmal AF.

Trial Registration number

NCT04563572.

Prognostic Implications and Efficacy of Catheter Ablation by Atrial Fibrillation Type

Background Catheter ablation (CA) for atrial fibrillation (AF) is preferred for paroxysmal AF (PAF) but selectively performed in patients with persistent AF (PersAF). This study aimed to investigate the prognostic differences and consequences of CA based on the AF type. Methods and Results Data from a multicenter AF cohort study were analyzed, categorizing patients as PAF or PersAF according to AF duration (≤7 or >7 days, respectively). A composite of all-cause death, heart failure hospitalization, stroke, and bleeding events during 2-year follow-up and changes in the Atrial Fibrillation Effect on Quality-of-life score were compared. Additionally, propensity score matching was performed to compare clinical outcomes of patients with and without CA in both AF types. Among 2788 patients, 51.6% and 48.4% had PAF and PersAF, respectively. Patients with PersAF had a higher incidence of the composite outcome (12.8% versus 7.2%; P<0.001) and smaller improvements in Atrial Fibrillation Effect on Quality-of-life scores than those with PAF. After adjusting for baseline characteristics, PersAF was an independent predictor of adverse outcomes (adjusted hazard ratio, 1.35 [95% CI, 1.30-1.78], P=0.031) and was associated with poor improvements in Atrial Fibrillation Effect on Quality-of-life scores. Propensity score matching analysis showed that the CA group had significantly fewer adverse events than the medication group among patients with PAF (odds ratio, 0.31 [95% CI, 0.18-0.68]; P=0.002). Patients with PersAF showed a similar but nonsignificant trend. Conclusions PersAF is a risk factor for worse clinical outcomes, including patients' health status. CA is associated with fewer adverse events, although careful consideration is required based on the AF type.

Diagnostic Value of a Wearable Continuous Electrocardiogram Monitoring Device (AT-Patch) for New-Onset Atrial Fibrillation in High-Risk Patients: Prospective Cohort Study

BACKGROUND

While conventional electrocardiogram monitoring devices are useful for detecting atrial fibrillation, they have considerable drawbacks, including a short monitoring duration and invasive device implantation. The use of patch-type devices circumvents these drawbacks and has shown comparable diagnostic capability for the early detection of atrial fibrillation.

OBJECTIVE

We aimed to determine whether a patch-type device (AT-Patch) applied to patients with a high risk of new-onset atrial fibrillation defined by the congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke, vascular disease, age 65-74 years, sex scale (CHA2DS2-VASc) score had increased detection rates.

METHODS

In this nonrandomized multicenter prospective cohort study, we enrolled 320 adults aged ≥19 years who had never experienced atrial fibrillation and whose CHA2DS2-VASc score was ≥2. The AT-Patch was attached to each individual for 11 days, and the data were analyzed for arrhythmic events by 2 independent cardiologists.

RESULTS

Atrial fibrillation was detected by the AT-Patch in 3.4% (11/320) of patients, as diagnosed by both cardiologists. Interestingly, when participants with or without atrial fibrillation were compared, a previous history of heart failure was significantly more common in the atrial fibrillation group (n=4/11, 36.4% vs n=16/309, 5.2%, respectively; P=.003). When a CHA2DS2-VASc score ≥4 was combined with previous heart failure, the detection rate was significantly increased to 24.4%. Comparison of the recorded electrocardiogram data revealed that supraventricular and ventricular ectopic rhythms were significantly more frequent in the new-onset atrial fibrillation group compared with nonatrial fibrillation group (3.4% vs 0.4%; P=.001 and 5.2% vs 1.2%; P<.001), respectively.

CONCLUSIONS

This study detected a moderate number of new-onset atrial fibrillations in high-risk patients using the AT-Patch device. Further studies will aim to investigate the value of early detection of atrial fibrillation, particularly in patients with heart failure as a means of reducing adverse clinical outcomes of atrial fibrillation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04857268; https://classic.clinicaltrials.gov/ct2/show/NCT04857268.