Atrial fibrillation: stroke prevention

Stroke prophylaxis after US emergency department diagnosis and discharge of patients with atrial fibrillation and flutter from 21 hospitals

BACKGROUND

Oral anticoagulation (OAC) reduces stroke and mortality risk in patients with non-valvular atrial fibrillation/flutter (AF). Patterns of OAC initiation upon discharge from US emergency departments (ED) are poorly understood. We sought to examine stroke prophylaxis actions upon, and shortly following, ED discharge of stroke-prone AF patients.

METHODS

We included all adults with a primary diagnosis of non-valvular AF, high stroke risk (CHA2DS2-VASc ≥ 2), low/intermediate bleeding risk (HAS-BLED < 4), and no recent (< 90 days) OAC at discharge from 21 community EDs (2010-2017). Annual rates of appropriate stroke prevention action (OAC Action) were calculated for eligible discharges and as defined as an OAC prescription or anticoagulation management service consultation within 14 days of ED discharge. We modeled OAC Action using a parsimonious Poisson regression with identity link adjusting for sex, age, race/ethnicity, stroke risk score (CHA2DS2-VASc), year of visit, provider race/ethnicity, number of ED beds, and presence of an outpatient observation unit, with the patient as a random effect.

RESULTS

We studied 9,603 eligible ED discharges (mean age 73.1 ± 11.4 years, 62.3% female), and mean CHA2DS2-VASc score 3.5 ± 1.5. From 2010 to 2017, OAC Action increased from 21.0% to 33.5%. Factors associated with lower OAC initiation included the following: female sex (-3.6%, 95% CI -5.4 to -1.9), age ≥ 85 vs < 64 years (-3.8%, 95% CI -6.7 to -1.0%), ED beds, n = 20 to 29 (-5.3%, 95% CI -8.36 to -2.4%), 30-49 (-3.8, 95% CI -6.5 to -1.2%), and 50 + (-7.1%, 95% CI -10.6 to -3.7%); with referent being the male sex, < 40 years, and fewer than 20 beds (18.1%, 95% CI 12.8 to 23.4). OAC initiation in 2017 was greater than in 2010 (16.0%, 95% CI 12.3 to 19.7%).

CONCLUSION

Within a community-based ED population of AF patients at high stroke risk, rates of appropriate stroke prevention action increased over the 7-year study period. Rates of AF thromboprophylaxis may be improved by addressing sex and age disparities, as females and those age ≥ 75 were less likely to receive indicated stroke prevention.

Apixaban in patients with nonvalvular atrial fibrillation, heart failure and low body weight: A report from a global federated research dataset

BACKGROUND

Atrial fibrillation (AF) and low body weight (BW, <60 kg) are common in patients with heart failure (HF). However, the safety and effectiveness of direct oral anticoagulants (DOACs) in this group remain unclear. This study compares the efficacy and safety of apixaban versus vitamin K antagonists (VKAs) in patients with nonvalvular AF, low BW and HF.

METHODS

We analysed 155,152 patients with HF and AF, weighing ≤100 kg and treated with oral anticoagulants (apixaban 86,493; VKA 68,659), from the TriNetX Global Research Network. Outcomes included ischaemic stroke/systemic embolism (SEE), clinically relevant bleedings, intracranial haemorrhage (ICH), all-cause death and net clinical benefit (composite of stroke/SEE, bleedings and all-cause death) across three BW categories: 60-100 kg (reference), 50-60 kg (low BW) and ≤50 kg (very low BW). Propensity score matching was used to balance the treatment groups.

RESULTS

Patients with low BW had a higher risk of adverse events compared to those with reference BW, regardless of treatment. Apixaban consistently reduced the risk of ischaemic stroke/SEE and bleeding (including ICH) across all BW ranges (all p-interaction >.10), and improved net clinical benefit compared to VKA (reference BW: HR .82 [95% CI: .80-.84]; low BW: HR .79 [95% CI: .74-.85]; very low BW: HR .86 [95% CI: .78-.95], p-interaction = .366). However, a significant BW-treatment interaction was observed for all-cause mortality, indicating reduced relative effectiveness of apixaban vs. VKA as BW decreases.

CONCLUSION

In this large real-world analysis, treatment with apixaban was associated with a superior effectiveness and safety profile compared to VKA in patients with AF, HF and low BW. These results remained consistent, albeit slightly attenuated, in patients with very low BW. These findings provide preliminary evidence supporting the use of apixaban in this high-risk population.

Ambulatory atrial fibrillation detection and quantification by wristworn AI device compared to standard holter monitoring

Timely detection of atrial fibrillation (AF) is crucial for the prevention of serious consequences such as stroke and heart failure, yet it remains challenging due to its often asymptomatic or paroxysmal nature. Wearable devices with artificial intelligence algorithms offer promising solutions. AF detection by the CardioWatch 287-2 (CW2), a wrist-worn photoplethysmography (PPG) and single-lead ECG device, was compared to 24-h Holter. Patient compliance, AF prevalence and AF burden were evaluated for 27 additional days. Data from 150 participants (mean age 64 ± 12 SD; 41% female) were analysed. The CW2's PPG and single-lead ECG algorithms achieved a specificity ≥98% and sensitivity ≥95% for AF detection, and 99% correlation for AF burden, compared to 24-h Holter. AF prevalence increased from 14.7% (24-h Holter) to 26.7% (28-day CW2). Thus, the wrist-worn device showed promising performance in detecting AF and determining AF burden. The trial was registered on ClinicalTrials.gov (NCT05899959) on June 2, 2023.

Residual risk prediction in anticoagulated patients with atrial fibrillation using machine learning: A report from the GLORIA-AF registry phase II/III

BACKGROUND

Although oral anticoagulation decreases the risk of thromboembolism in patients with atrial fibrillation (AF), a residual risk of thrombotic events still exists. This study aimed to construct machine learning (ML) models to predict the residual risk in these patients.

METHODS

Patients with newly diagnosed non-valvular AF were collected from the Global Registry on Long-Term Oral Anti-Thrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) registry. To predict the residual risk of the composite outcome of thrombotic events (defined as ischemic stroke, systemic embolism, transient ischemic attack and myocardial infarction), we constructed four prediction models using the logistic regression (LR), random forest, light gradient boosting machine and extreme gradient boosting machine ML algorithms. Performance was mainly evaluated by area under the receiver-operating characteristic curve (AUC), g-means and F1 scores. Feature importance was evaluated by SHapley Additive exPlanations.

RESULTS

15,829 AF patients (70.33 ± 9.94 years old, 55% male) taking oral anticoagulation were included in our study, and 641 (4.0%) had residual risk, sustaining thrombotic events. In the test set, LR had the best performance with higher AUC trend of 0.712. RF has highest g-means of 0.295 and F1 score of 0.249. This was superior when compared with the CHA2DS2-VA score (AUC 0.698) and 2MACE score (AUC 0.696). Age, history of TE or MI, OAC discontinuation, eGFR and sex were identified as the top five factors associated with residual risk.

CONCLUSION

ML algorithms can improve the prediction of residual risk of anticoagulated AF patients compared to clinical risk factor-based scores.

Strategies for the prevention of ischemic stroke in atrial fibrillation in East Asia: clinical features, changes and challenges

East Asian populations exhibit a high burden of atrial fibrillation (AF) and AF-related ischemic strokes. The countries/regions in East Asia have diversities regarding patient characteristics and varying patient care represented by different adherence rates to the ABC (Atrial Fibrillation Better Care) pathway. Two changes, "from non-anticoagulation to direct oral anticoagulants (DOACs)" and "from lower dosing to appropriate dosing DOACs", have been identified in East Asia and have been temporally linked to improved clinical outcomes in AF patients. Additional efforts are necessary to further reduce the stroke risk among AF patients, including increased communication with other specialists/societies, the initiation of prospective studies or clinical trials in Asia, and the implementation of evidence-based holistic or integrated care management based on the ABC pathway.

Catheter ablation using pulsed-field energy: Advantages and limitations compared with conventional energy

Atrial fibrillation (AF) poses significant risks of heart failure and stroke, emphasizing effective treatment. Catheter ablation using thermal energy sources, such as radiofrequency or cryoballoon ablation, has shown greater success in maintaining sinus rhythm compared with drug therapy. However, thermal ablation (TA) is associated with serious complications, such as atrial-esophageal fistula, phrenic nerve palsy, and pulmonary vein stenosis. Pulsed-field ablation (PFA) is an emerging ablation energy source that uses electroporation to selectively target cardiac tissue while sparing adjacent structures such as nerves and blood vessels. Two randomized controlled trials have demonstrated that PFA is comparable to TA in both efficacy and safety at a 1-year follow-up and had shorter procedure times. A review of six meta-analyses consistently showed shorter procedural times for PFA across all studies. Additionally, three out of the four recent studies with large samples reported lower recurrence rates with PFA. Regarding complication rates, four out of four studies showed lower incidences of phrenic nerve injury with PFA, and two out of three studies reported lower rates of esophageal injury with PFA. However, four out of four studies indicated higher incidences of cardiac tamponade with PFA, highlighting the need for caution among early-career operators. Furthermore, careful monitoring is required considering the possible unforeseen complications specific to PFA and the lack of long-term follow-up data. Despite these concerns, PFA shows promise as a safer, more effective, and efficient alternative to TA for AF, particularly as operator experience and device technology continue to advance.

Renal function and adverse clinical events in anticoagulated patients with atrial fibrillation: insights from the GLORIA-AF Registry Phase III

Renal function, assessed by creatinine clearance (CrCl), affects the efficacy and safety of oral anticoagulant (OAC) therapy in patients with atrial fibrillation (AF). To investigate the association between CrCl and the risk of clinical adverse events and compare the safety profiles of vitamin K antagonists (VKA) and non-vitamin K antagonist oral anticoagulants (NOAC). Patients with newly diagnosed AF (< 3 months before baseline visit) were collected from the prospective Global Registry on Long-Term Oral Anti-Thrombotic Treatment in Patients with Atrial Fibrillation (GLORIA-AF) registry Phase III. Clinical events assessed included the composite outcome (all-cause death, thromboembolism, and major bleeding), cardiovascular (CV) death, myocardial infarction (MI), and other single outcomes. 10,594 AF patients (mean age 70.35 ± 9.92 years; 55% male; 73% on NOAC) were included. Increasing CrCl was associated with decreased risks of all cause death, composite outcomes and CV-death with in patients with CrCl < 80 mL/min. Multivariate Cox models indicated that compared to VKA, NOAC was associated with lower risks of all cause death (adjusted hazard ratio [aHR] 0.68, 95% CI 0.58-0.78), composite outcomes (aHR 0.77, 95% CI 0.69-0.86), CV-death (aHR 0.70, 95% CI 0.56-0.87), and major bleeding (aHR 0.74, 95% CI 0.61-0.91) in AF patients. For CrCl < 30 mL/min, lower risks of all-cause death, composite outcomes and CV death were related to NOAC therapy. In this large prospective global registry, NOACs were associated with better outcomes compared with VKA for patients with normal or impaired renal function.

Current Strategies for Atrial Fibrillation Prevention and Management: Taming the Commonest Cardiac Arrhythmia

Atrial fibrillation (AF) is the commonest cardiac arrhythmia, constituting a major cause of morbidity and mortality, with an age-dependent incidence and prevalence ranging from 1-2% in the general population to ~10% in persons aged >60 years. The global prevalence of AF is rapidly increasing, mostly due to the aging population. If not properly and timely managed, this arrhythmia adversely affects left ventricular function, increases the risk of stroke five-fold, impairs quality of life, and shortens longevity. There is a genetic, hence non-modifiable, predisposition to the arrhythmia, while several life-style and cardiometabolic inciting factors, such as hypertension, heart failure, coronary disease, metabolic syndrome, alcohol use, and thyroid disorders, can be addressed, attesting to the importance of a holistic approach to its management. Thromboembolism is a serious consequence of AF, which could lead to a disabling stroke or have a lethal outcome. The risk of a thromboembolic complication can be estimated as based on a scoring system that takes into consideration the patient's age, previous thromboembolic events, and clinical comorbidities. In addition, rapid AF could affect cardiac performance, leading to an elusive type of arrhythmia- induced cardiomyopathy and heart failure with grave consequences if undetected and untreated. Furthermore, AF may cause silent brain infarcts and/or its hemodynamic perturbations can account for a type of dementia that needs to be taken into account, emphasizing the need for AF screening and prevention strategies. All these issues are herein detailed, the causes of the arrhythmia are tabulated, and an algorithm illustrates our current approach to its management.

Intravenous thrombolysis and mechanical thrombectomy in acute stroke patients on direct oral anticoagulants

Intravenous thrombolysis and mechanical thrombectomy reduce morbidity and improve functional outcome in ischemic stroke. However, acute recanalization therapies may increase the risk of symptomatic intracranial hemorrhage due to its effects on the brain tissue. An increasing proportion of patients with ischemic stroke are using direct oral anticoagulants (DOACs). While current international guidelines recommend against intravenous thrombolysis in patients with intake of DOACs within the last 48 h, they also highlight lack of evidence in the area. Based on these guidelines, a significant proportion of patients are consequently disqualified from intravenous thrombolysis. Measuring anticoagulant activity before intravenous thrombolysis has been suggested as a way to select patients with low risk of symptomatic intracranial hemorrhage, but uncertainty exists about feasibility, validity, availability and costs. Reversal agents have demonstrated potential in facilitating safer intravenous thrombolysis administration, though their efficacy is not established in randomized controlled trials, and logistical and cost-related barriers limit their widespread use. During the last couple of years several large cohort studies reported no significant increase in symptomatic intracranial hemorrhage among selected patients on DOACs receiving intravenous thrombolysis compared to those not on anticoagulants, even without the use of DOAC plasma levels or reversal agents. Mechanical thrombectomy appears to be generally safe in patients with recent DOAC intake. The aim of this review is to discuss the uncertainty around the safety and efficacy of intravenous thrombolysis and thrombectomy in patients with a recent intake of DOAC, summarize existing knowledge, and outline potential approaches.

An International Consensus Practical Guide on Left Atrial Appendage Closure for the Non-implanting Physician: Executive Summary

Many patients with atrial fibrillation (AF) who are in need of stroke prevention are not treated with oral anticoagulation or discontinue treatment shortly after its initiation. Despite the availability of direct oral anticoagulants (DOACs), such undertreatment has improved somewhat but is still evident. This is due to continued risks of bleeding events or ischemic strokes while on DOAC, poor treatment compliance, or aversion to anticoagulant therapy. Because of significant improvements in procedural safety over the years left atrial appendage closure (LAAC), using a catheter-based, device implantation approach, is increasingly favored for the prevention of thromboembolic events in AF patients who cannot have long-term oral anticoagulation. This article is an executive summary of a practical guide recently published by an international expert consensus group, which introduces the LAAC devices and briefly explains the implantation technique. The indications and device follow-up are more comprehensively described. This practical guide, aligned with published guideline/guidance, is aimed at those non-implanting physicians who may need to refer patients for consideration of LAAC.

Plasma apixaban concentrations and thrombin generation assay parameters in response to dose reduction for atrial fibrillation

AIMS

To investigate plasma apixaban concentrations and thrombin generation assay (TGA) parameters across different apixaban doses in atrial fibrillation patients who had dose-reduction criteria for apixaban.

METHODS

This observational study included 374 patients (mean age 75.6 ± 7.7 years, 54.8% female) with dose-reduction criteria for apixaban. The patients were divided into 3 groups: (i) on-label standard dose (5 mg twice daily, n = 166); (ii) on-label reduced dose (2.5 mg twice daily, n = 55); and (iii) off-label underdose (2.5 mg twice daily, n = 153). Apixaban concentrations determined via the anti-Xa assay and TGA parameters were compared at trough levels.

RESULTS

The off-label underdose group exhibited significantly lower apixaban trough concentrations than the on-label reduced-dose and standard-dose groups (56.7 ± 42.9 vs. 83.7 ± 70.4 vs. 129.9 ± 101.8 ng/mL, all P < .001). Less than 70% of all patients fell within the expected range of apixaban concentrations. Proportions exceeding the upper limit of the expected range were significantly lower in the off-label underdose group (1.3%) than in the on-label reduced-dose (9.1%, P = .005) and standard-dose (12.7%, P < .001) groups. The TGA parameters showed the on-label standard-dose group displaying the lowest thrombogenic profiles. Lower creatinine clearance was the most significant predictor of higher apixaban concentrations.

CONCLUSION

Off-label underdosed apixaban resulted in lower apixaban concentrations than both on-label standard and reduced-dose regimens. A considerable proportion of the patients exhibited apixaban concentrations outside the expected range, suggesting the potential benefits of plasma concentration monitoring. Further studies are needed to compare dosages directly, investigate the impact of plasma apixaban concentration monitoring and validate the current dose-reduction criteria.

Identification and Functional Investigation of SOX4 as a Novel Gene Underpinning Familial Atrial Fibrillation

Background: Atrial fibrillation (AF) signifies the most prevalent supraventricular arrhythmia in humans and may lead to cerebral stroke, cardiac failure, and even premature demise. Aggregating strong evidence points to genetic components as a cornerstone in the etiopathogenesis of familial AF. However, the genetic determinants for AF in most patients remain elusive. Methods: A 4-generation pedigree with idiopathic AF and another cohort of 196 unrelated patients with idiopathic AF as well as 278 unrelated healthy volunteers were recruited from the Chinese population of Han ethnicity. A family-based whole-exome sequencing examination followed by a Sanger sequencing assay in all research subjects was implemented. The functional impacts of the identified SOX4 mutations were explored via a dual-reporter assay. Results: Two new heterozygous SOX4 mutations, NM_003107.3: c.211C>T; p.(Gln71*) and NM_003107.3: c.290G>A; p.(Trp97*), were observed in the family and 1 of 196 patients with idiopathic AF, respectively. The two mutations were absent in the 278 control individuals. The biochemical measurements revealed that both Gln71*- and Trp97*-mutant SOX4 failed to transactivate GJA1 (Cx43). Moreover, the two mutations nullified the synergistic activation of SCN5A by SOX4 and TBX5. Conclusions: The findings first indicate SOX4 as a gene predisposing to AF, providing a novel target for antenatal genetic screening, individualized prophylaxis, and precision treatment of AF.

Comprehensive Stroke Management: a Guide for Hospitalists

Stroke is a devastating clinical condition characterized by an acute neurological impairment secondary to cerebrovascular disease. Globally, stroke is the second leading cause of mortality and disability, with prominent risk factors including age, hypertension, hyperlipidemia, atrial fibrillation, diabetes, smoking, preexisting vascular anomalies and obesity. Acute neurological deficits are commonly encountered in the inpatient wards. Heightened clinical suspicion and prompt evaluation involving neurological examination and imaging are crucial for effective management. At many hospitals, hospitalists are tasked with managing stroke patients with consultation from neurologists. The management of stroke is constantly evolving as new and advanced therapies emerge. This review of the literature seeks to summarize current practice in stroke management in hopes it is helpful to those hospitalists who care for this patient population frequently. A search of the literature was performed to summarize current research as well as management and therapeutic strategies.

Multidisciplinary Approach in Atrial Fibrillation: As Good as Gold

Atrial fibrillation (AF) represents the most common sustained arrhythmia necessitating dual focus: acute complication management and sustained longitudinal oversight to modulate disease progression and ensure comprehensive patient care over time. AF is a multifaceted disorder; due to such a great number of potential exacerbating conditions, a multidisciplinary team (MDT) should manage AF patients by cooperating with a cardiologist. Effective management of AF patients necessitates the implementation of a well-coordinated and tailored care pathway aimed at delivering optimized treatment through collaboration among various healthcare professionals. Management of AF should be carefully evaluated and mutually agreed upon in consultation with healthcare providers. It is crucial to recognize that treatment may evolve due to the emergence of new risk factors, symptoms, disease progression, and advancements in treatment modalities. In the context of multidisciplinary AF teams, a coordinated approach involves assembling a diverse team tailored to meet individual patients' unique needs based on local services' availability.