Ischemic Stroke Risk in Patients With Nonvalvular Atrial Fibrillation: JACC Review Topic of the Week

Advances in Atrial Fibrillation Management: A Guide for General Internists

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, impacting approximately 6.1 million adults in the United States, with projections to increase two-fold by 2030. AF significantly increases the risk of stroke and other adverse cardiovascular events, leading to increased morbidity and mortality. The 2023 ACC/AHA/ACCP/HRS guidelines present a paradigm shift in AF management, moving from a duration-based classification to a more comprehensive, patient-centered approach. This includes a novel AF classification system that emphasizes early detection and intervention, including risk factors and lifestyle modification tailored to each patient's risk profile. Moreover, the recommendations advocate for a multidisciplinary care model, ensuring coordinated management involving primary care providers and specialists. Primary care providers play a crucial role in initiating risk factor management and lifestyle interventions, even before the development of AF. This review aims to thoroughly examine the guidelines for the diagnosis and management of AF and equip general internists with the necessary insights to navigate the evolving landscape of AF care effectively.

Small extracellular vesicles associated miRNA in myocardial fibrosis

Myocardial fibrosis involves the loss of cardiomyocytes, myocardial fibroblast proliferation, and a reduction in angiogenesis, ultimately leading to heart failure, Given its significant implications, it is crucial to explore novel therapies for myocardial fibrosis. Recently one emerging avenue has been the use of small extracellular vesicles (sEV)-carried miRNA. In this review, we summarize the regulatory role of sEV-carried miRNA in myocardial fibrosis. We explored not only the potential diagnostic value of circulating miRNA as biomarkers for heart disease but also the therapeutic implications of sEV-carried miRNA derived from various cellular sources and applications of modified sEV. This exploration is paramount for researchers striving to develop innovative, cell-free therapies as potential drug candidates for the management of myocardial fibrosis.

Myeloproliferative Neoplasms and Cardiovascular Disease: A Review

OPINION STATEMENT

Myeloproliferative neoplasms (MPN) are a heterogenous group of disorders of clonal hematopoiesis characterized by constitutive activation of the JAK/STAT signaling pathway leading to proliferation of blood cells. Cardiovascular disease (CVD) contributes significantly to the morbidity and mortality of patients with MPN. Particularly well-known CVD complications of MPNs are arterial and venous thrombotic events. However, MPNs are also associated with other forms of CVD including atrial fibrillation, heart failure, and pulmonary hypertension. Recent studies have characterized outcomes of patients with MPN and CVD, including acute myocardial infarction (AMI), heart failure, atrial fibrillation, and pulmonary hypertension. Additionally, optimal cardiovascular disease prevention strategies in patients with MPN are not yet clear. Further investigation is warranted to improve CVD outcomes in patients with MPN. Clinicians should be aware of cardiovascular complications of MPN, including thrombotic as well as non-thrombotic complications (heart failure, arrhythmias, pulmonary hypertension).

Exploring the link between blood pressure variability and atrial fibrillation: current insights and future directions

Atrial fibrillation (AF) is the most common heart rhythm disorder, especially in people over the age of 50, which affects more than 40 million people worldwide. Many studies have highlighted the association between hypertension with the development of AF. Blood pressure variability (BPV) is a dynamic size obtained by recording blood pressure oscillations using specific readings and at specific time intervals. A multitude of internal and external factors shape BPV while at the same time constituting a common pathogenetic pathway with the development of AF. Until recently, BPV has been applied exclusively in preclinical and clinical studies, without significant implications in clinical practice. Indeed, even from the research side, the determination of BPV is limited to patients without AF due to doubts about the accuracy of its measurement methods in patients with AF. In this review, we present the current evidence on common pathogenic pathways between BPV and AF, the reliability of quantification of BPV in patients with AF, the prognostic role of BPV in these patients, and discuss the future clinical implications of BPV in patients with AF.

Serum protein profiling reveals mechanism of activated thrombus formation in patients with stroke and atrial fibrillation

Stroke is an acute cerebrovascular disease in which blood flow to the brain is suddenly disrupted, causing damage to nerve cells. It involves complex and diverse pathophysiological processes and the treatment strategies are also diverse. The treatment for patients with stroke and atrial fibrillation (AF) is aimed at suppressing thrombus formation and migration. However, information regarding the protein networking involved in different thrombus formation pathways in patients with AF and stroke is insufficient. We performed protein profiling of patients with ischemic stroke with and without AF to investigate the mechanisms of thrombus formation and its pathophysiological association while providing helpful information for treating and managing patients with AF. These two groups were compared to identify the protein networks related to thrombus formation in AF. We observed that patients with ischemic stroke and AF had activated inflammatory responses induced by C-reactive protein, lipopolysaccharide-binding protein, and alpha-1-acid glycoprotein 1. In contrast, thyroid hormones were increased due to a decrease in transthyretin and retinol-binding protein 4 levels. The mechanism underlying enhanced cardiac activity, vasodilation, and the resulting thrombosis pathway were confirmed in AF. These findings will play an essential role in improving the prevention and treatment of AF-related stroke.

Chronological vs Biological Age in Interventional Cardiology: A Comprehensive Approach to Care for Older Adults: JACC Family Series

Aging is the gradual decline in physical and physiological functioning leading to increased susceptibility to stressors and chronic illnesses, including cardiovascular disease. With an aging global population, in which 1 in 6 individuals will be older than 60 years by 2030, interventional cardiologists are increasingly involved in providing complex care for older individuals. Although procedural aspects remain their main clinical focus, interventionalists frequently encounter age-associated risks that influence eligibility for invasive care, decision making during the intervention, procedural adverse events, and long-term management decisions. The unprecedented growth in transcatheter interventions, especially for structural heart diseases at extremes of age, have pushed age-related risks and implications for cardiovascular care to the forefront. In this JACC state-of-the-art review, the authors provide a comprehensive overview of the aging process as it relates to cardiovascular interventions, with special emphasis on the difference between chronological and biological aging. The authors also address key considerations to improve health outcomes for older patients during and after their invasive cardiovascular care. The role of "gerotherapeutics" in interventional cardiology, technological innovation in measuring biological aging, and the integration of patient-centered outcomes in the older adult population are also discussed.

Cardiac imaging correlates and predictors of stroke in patients with atrial fibrillation: a meta-analysis

BACKGROUND

New nonclinical parameters are needed to improve the current stroke risk stratification schemes for patients with atrial fibrillation. This study aimed to summarize data on potential cardiac imaging correlates and predictors of stroke or systemic embolism in patients with atrial fibrillation.

METHODS

MEDLINE, EMBASE, and Web of Science were searched to identify all published studies providing relevant data through 16 November 2022. Random effects meta-analysis method was used to pool estimates.

RESULTS

We included 64 studies reporting data from a pooled population of 56 639 patients. Left atrial spontaneous echo-contrast [adjusted odds ratio (aOR) 3.32, 95% confidence interval (CI) 1.98-5.49], nonchicken wing left atrial appendage (LAA) morphology (aOR 2.15, 95% CI 1.11-4.18), left atrial enlargement (aOR 2.12, 95% CI 1.45-3.08), and higher LAA orifice diameter (aOR 1.56, 95% CI 1.18-2.05) were highly associated with stroke. Other parameters associated with stroke included higher left atrial sphericity (aOR 1.14, 95% CI 1.01-1.29), higher left atrial volume (aOR 1.03, 95% CI 1.01-1.04), higher left atrial volume index (aOR 1.014, 95% CI 1.004-1.023), lower left atrial reservoir strain [adjusted hazard ratio (aHR) 0.86, 95% CI 0.76-0.98], higher left ventricular mass index (aOR 1.010, 95% CI 1.005-1.015) and E / e' ratio (aOR 1.12, 95% CI 1.07-1.16). There was no association between LAA volume (aOR 1.37, 95% CI 0.85-2.21) and stroke.

CONCLUSION

These cardiac imaging parameters identified as potential predictors of thromboembolism may improve the accuracy of stroke risk stratification schemes in patients with atrial fibrillation. Further studies should evaluate the performance of holistic risk scores including clinical factors, biomarkers, and cardiac imaging.

Safety and efficacy of direct oral anticoagulants in comparison to warfarin in obese patients with atrial fibrillation: A systematic review and meta-analysis

Background and Aim

Obesity affects nearly 650 million adults worldwide, and the prevalence is steadily rising. This condition has significant adverse effects on cardiovascular health, increasing the risk of hypertension, coronary artery disease, heart failure, and atrial fibrillation (AF). While anticoagulation for obese patients with AF is a well-established therapy for the prevention of thromboembolism, the safety and efficacy of different anticoagulants in this specific population are not well explored. This meta-analysis aimed to compare direct oral anticoagulants (DOAC) to vitamin K antagonists in obese populations with AF.

Methods

The PRISMA guidelines were followed for this meta-analysis, registered in PROSPERO (CRD42023392711). PubMed, PubMed Central, Embase, Cochrane Library, and Scopus databases were searched for relevant articles from inception through January 2023. Two independent authors screened titles and abstracts, followed by a full-text review in Covidence. Data were extracted in Microsoft Excel and analyzed using RevMan v5.4 using odds ratio as an effect measure.

Results

Two thousand two hundred fifty-nine studies were identified from the database search, and 18 were included in the analysis. There were statistically significant reductions in the odds of ischemic and hemorrhagic stroke in the DOAC group compared with the VKA group (OR 0.70, CI 0.66-0.75) and (OR 0.47, CI 0.35-0.62), respectively. In addition, the DOAC group exhibited lower odds of systemic embolism (OR 0.67, CI 0.54-0.83), major bleeding (OR 0.62, CI 0.54-0.72), and composite outcome (OR 0.72, CI 0.63-0.81).

Conclusion

Based on the findings from this meta-analysis, DOACs demonstrate superior safety and efficacy in obese patients with AF compared with VKAs. These results may have significant implications for guiding anticoagulation strategies in this patient population.

Enhancing the evaluation of acute ischemic stroke risk in individuals with non-valvular atrial fibrillation by including laboratory indicators

To investigate the clinical significance of the CHA2DS2-VASc-60 score, lipoprotein (a) [Lp(a)], red blood cell distribution width (RDW), and their combined effect in patients with non-valvular atrial fibrillation (NVAF) who experience acute ischemic stroke (AIS). This retrospective analysis was conducted on the clinical data of hospitalized patients with NVAF at the Third Affiliated Hospital of Anhui Medical University between April 1, 2020, and April 1, 2023. Based on the diagnosis of acute ischemic stroke (AIS), the patients were divided into two groups: the AIS group (150 cases of NVAF patients with comorbid AIS) and the non-AIS group (163 cases of NVAF patients without AIS). We performed CHA2DS2-VASc-60 scoring for all patients and collected their laboratory indicators and echocardiographic indicators during hospitalization. The study comprised 313 individuals with NVAF in total. There is a statistically significant difference (P < 0.05) in the comparison of CHA2DS2-VASc-60 score (5.68 ± 1.12 vs. 3.67 ± 1.47), Lp(a) [23.98 (13.28, 42.22) vs. 14.32 (7.96, 21.91)] and RDW (13.67 ± 1.25 vs. 12.94 ± 0.76) between NVAF patients with and without concomitant AIS. The results of the Spearman correlation analysis demonstrate a positive association between Lp(a) and RDW levels and both the CHA2DS2-VASc score and the CHA2DS2-VASc-60 score in patients with NVAF. Multivariate logistic regression analysis revealed that CHA2DS2-VASc-60 score [OR = 6.549, 95% CI: 4.110-10.433, P < 0.05], Lp(a) [OR = 1.023, 95% CI: 1.005-1.041, P < 0.05], and RDW [OR = 1.644, 95% CI: 1.071-2.525, P < 0.05] were independent risk factors for AIS in patients with non-valvular atrial fibrillation (NVAF). The receiver operator characteristic (ROC) curves showed that the area under the curve of CHA2DS2-VASc-60 score, Lp(a), RDW, and CHA2DS2-VASc-60 score combined with Lp(a) and RDW predicted that NVAF patients with AIS were 0.881 [95% CI: 0.804-0.906], 0.685 [95% CI: 0.626-0.744], 0.695 [95% CI: 0.637-0.754], and 0.906 [95% CI: 0.845-0.921], respectively. The CHA2DS2-VASc-60 score, Lp(a), and RDW were significantly increased in NVAF patients with AIS, which were independent risk factors for NVAF patients with AIS. The combination of the three has a high predictive capacity for NVAF patients with AIS.

Slow blood-flow in the left atrial appendage is associated with stroke in atrial fibrillation patients

Background

Atrial fibrillation (AF) patients are at high risk of stroke with ∼90% clots originating from the left atrial appendage (LAA). Clinical understanding of blood-flow based parameters and their potential association with stroke for AF patients remains poorly understood. We hypothesize that slow blood-flow either in the LA or the LAA could lead to the formation of blood clots and is associated with stroke for AF patients.

Methods

We retrospectively collected cardiac CT images of paroxysmal AF patients and dichotomized them based on clinical event of previous embolic event into stroke and non-stroke groups. After image segmentation to obtain 3D LA geometry, patient-specific blood-flow analysis was performed to model LA hemodynamics. In terms of geometry, we calculated area of the pulmonary veins (PVs), mitral valve, LA and LAA, orifice area of LAA and volumes of LA and LAA and classified LAA morphologies. For hemodynamic assessment, we quantified blood flow velocity, wall shear stress (WSS, blood-friction on LA wall), oscillatory shear index (OSI, directional change of WSS) and endothelial cell activation potential (ECAP, ratio of OSI and WSS quantifying slow and oscillatory flow) in the LA as well as the LAA. Statistical analysis was performed to compare the parameters between the groups.

Results

Twenty-seven patients were included in the stroke and 28 in the non-stroke group. Examining geometrical parameters, area of left inferior PV was found to be significantly higher in the stroke group as compared to non-stroke group (p = 0.026). In terms of hemodynamics, stroke group had significantly lower blood velocity (p = 0.027), WSS (p = 0.018) and higher ECAP (p = 0.032) in the LAA as compared to non-stroke group. However, LAA morphologic type did not differ between the two groups. This suggests that stroke patients had significantly slow and oscillatory circulating blood-flow in the LAA, which might expose it to potential thrombogenesis.

Conclusion

Slow flow in the LAA alone was associated with stroke in this paroxysmal AF cohort. Patient-specific blood-flow analysis can potentially identify such hemodynamic conditions, aiding in clinical stroke risk stratification of AF patients.

Left atrial appendage occlusion in patients suffering from advanced chronic kidney disease (stage 4 and 5). Long-term follow-up

INTRODUCTION AND OBJECTIVES

Advanced chronic kidney disease (A-CKD) combined with atrial fibrillation increases the risk of both thrombogenic and bleeding events. Left atrial appendage occlusion (LAAO) may be an alternative to oral anticoagulation to prevent thromboembolic events. We aimed to evaluate the outcomes of LAAO in patients with A-CKD.

METHODS

Comparison at long-term follow-up of patients diagnosed with and without A-CKD (eGFR<30 mL/min/1.73 m2 ) who underwent LAAO between 2009 and May 2022.

RESULTS

Five hundred seventy-three patients were included. Eighty-one (14%) were diagnosed with A-CKD. There were no differences in sex, age, and cardiovascular risk factors, except for diabetes which was more frequent in patients with A-CKD. The control group had higher rates of stroke, both ischemic and hemorrhagic. There were no differences in the CHA2 DS2 -VASc score, although A-CKD patients had a higher bleeding risk according to the HASBLED scale. Global procedural success was 99.1%. At follow-up, there were no differences in stroke rate: at 1-year (HR: 1.22, IC-95%: 0.14-10.42, p = 0.861); at 5-years (HR: 0.60, IC-95%: 0.08-4.58, p = 0.594). Although bleeding events were higher in the A-CKD group, no differences were found in major bleeding (defined BARC ≥ 3) at 1-year (HR: 1.34, IC-95%: 0.63-2.88, p = 0.464) or at 5-years follow-up (HR: 1.30, IC-95%: 0.69-2.48, p = 0.434). Mortality rate at 5 years was higher in the A-CKD patients (HR: 1.84, IC-95%: 1.18-2.87, p = 0.012).

CONCLUSIONS

LAAO is an effective and safe treatment in A-CKD patients to prevent ischemic events and bleeding. This strategy could be an alternative to oral anticoagulation in this high-risk group of patients.

Development and Validation of a New Nomogram Model for Predicting Acute Ischemic Stroke in Elderly Patients with Non-Valvular Atrial Fibrillation: A Single-Center Cross-Sectional Study

Background and Aims

Non-valvular atrial fibrillation (NVAF) patients face a 3-5 times greater risk of acute ischemic stroke (AIS) compared to those without NVAF. This study aims to establish a novel clinical prediction model for AIS in elderly patients with NVAF by incorporating relevant biomarker indicators.

Methods

A total of 301 individuals diagnosed with NVAF were selected for this investigation at the Third Affiliated Hospital of Anhui Medical University. Based on the presence of AIS, patients were categorized into two groups: the Stroke Cohort and the Non-Stroke Cohort. Predictor screening was performed using the least absolute shrinkage and selection operation (LASSO) regression algorithm. The binary logistic regression equation was applied to fit the model, followed by internal validation using the bootstrap resampling method (1000 times). Receiver operating characteristic (ROC) curve, calibration degree curve plots, and clinical decision curve analysis (DCA) were generated, respectively. Finally, a nomogram was constructed to present the prediction model.

Results

The final results of this study revealed that neutrophil-to-lymphocyte ratio (NLR), red cell distribution width (RDW), lipoprotein(a) (Lp(a)), systolic pressure, history of stroke, hyperlipidemia were independent risk factors for AIS in elderly patients with NVAF (P<0.05). And the high-density lipoprotein cholesterol (HDL-C) was an independent protective factor (P<0.05). By incorporating these indicators, a nomogram prediction model for predicting AIS in elderly patients with NVAF was constructed. Comparative analysis between the nomogram predictive model and CHA2DS2-VASc score revealed that the AUC of the nomogram predictive model surpassed that of the CHA2DS2-VASc score (AUC: 0.881vs 0.850).

Conclusion

NLR, RDW, Lp(a), SP, history of stroke, hyperlipidemia, and HDL-C emerge as independent prognostic factors for acute ischemic stroke in elderly patients with non-valvular atrial fibrillation. The predictive utility of the nomogram model may potentially surpass that of the CHA2DS2-VASc scoring system.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Low bleeding acceptance is associated with increased death risk in patients with atrial fibrillation on oral anticoagulation

Bleeding is the most feared complication of anticoagulation. We sought to investigate whether the bleeding risk acceptance has a prognostic value during long-term follow-up in the era of direct oral anticoagulants (DOACs) among patients with atrial fibrillation (AF). We studied 167 consecutive AF outpatients [aged 68.8 SD 10.6 years; 141 (84.4%) on DOACs]. The bleeding acceptance was assessed based on the Bleeding Ratio defined as the declared maximum number of major bleedings that a patient would be willing to accept to prevent one major stroke. We recorded cerebrovascular ischemic events, major or clinically relevant non-major bleeds (CRNMB), and mortality. A median Bleeding Ratio was 4 (IQR 2-5). During follow-up of 946 patient-years, cerebrovascular ischemic events and/or death were observed in 28 patients (3.3%/ year) and major bleeding or CRNMB in 33 (4.6%/ year). The Bleeding Ratio was lower in patients who experienced cerebrovascular events or death (p = 0.004), but not bleeding. Patients with the Bleeding Ratio 0-3 were more often non-persistent to the OAC therapy, and more likely to have cerebrovascular event or die than those with higher bleeding acceptance (odds ratio 2.55; 0.95% CI 1.08-6.02) which was driven by the impact on mortality. The multiple Cox proportional hazards model showed that lower Bleeding Ratio, higher CHA2DS2-VASc score, and older age predicted cerebrovascular events or death during follow-up. AF patients who are willing to accept fewer serious bleedings to avoid major stroke during anticoagulation are more likely to experience death and/or cerebrovascular ischemic events, but not bleeding, what might be related to non-persistence.

Risk of ischemic stroke associated with direct oral anticoagulants discontinuation on patients with non-valvular atrial fibrillation

INTRODUCTION

Although direct oral anticoagulants' (DOACs) prescriptions have experienced immense growth in the last decade, the proportion of discontinuers is still common yielding an increased risk of ischemic stroke (IS) onset.

AIMS

We aimed to estimate the association between DOACs discontinuation and risk of IS among patients with non-valvular atrial fibrillation (NVAF).

METHODS

We used data from a cohort of new DOACs users, followed patients from the first DOAC prescription date up to IS (index date) and conducted a nested case-control analysis using conditional logistic regression. Adjusted odds ratios, 95% confidence intervals were calculated for discontinuation of DOACs (current use compared with past use). The latter, subdivided among those stopping treatment 3 to 2 months and 6 and 3 months prior to index date. The effect of naïve current users against IS onset compared with non-naïve current users was also evaluated.

RESULTS

DOACs discontinuation showed an OR of IS of 1.47 (95% CI: 1.02-2.12); estimates were 2.51 (95% CI: 1.84-3.42) for whom discontinued treatment within months 3 and 2 and 1.43 (95% CI: 0.96-2.13) for those between months 6 and 3 prior to index date. Analyzing DOACs individually, risk of IS associated with past users compared with current users: 1.98 (95% CI: 1.25-3.12) for apixaban, 1.38 (95% CI: 0.40-4.72) for edoxaban, 1.98 (95% CI: 1.24-2.65) for dabigatran and 1.87 (95% CI: 1.26-2.76) for rivaroxaban. Similar results were found when stratified by naïve and non-naïve users.

CONCLUSIONS

DOACs' discontinuation is associated with higher risk of IS, especially in the second and third months following interruption.

High-risk carotid plaques and incident ischemic stroke in patients with atrial fibrillation in the Cardiovascular Health Study

BACKGROUND AND PURPOSE

Whether carotid artery disease could improve stroke risk stratification tools in patients with atrial fibrillation (AF) remains uncertain. This study was undertaken to investigate the risk of ischemic stroke associated with occlusive and nonocclusive carotid atherosclerotic disease in patients with AF in the prospective population-based Cardiovascular Health Study.

METHODS

We included participants aged ≥65 years with AF. We used multivariable Cox regression analysis to explore the risk of ischemic stroke associated with the percentage of carotid stenosis, plaque irregularity, echogenicity, and vulnerability (markedly irregular, ulcerated, or hypoechoic plaques).

RESULTS

A total of 1398 participants were included (55.2% female, 61.7% aged 65-74 years). The maximum carotid stenosis was <50%, 50%-99%, and 100% in 94.5%, 5%, and 0.5% of participants, respectively. High-risk plaques based on echogenicity and plaque irregularity were found in 25.6% and 8.9% of participants, respectively. After a median follow-up of 10.9 years (interquartile range = 7.5-15.6), 298 ischemic strokes were recorded. There was no difference in the incidence of ischemic stroke according to the degree of carotid artery stenosis (p = 0.44), plaque echogenicity (low vs. high risk, p = 0.68), plaque irregularity (low vs. high risk, p = 0.55), and plaque vulnerability (p = 0.86). The CHA₂DS₂-VASc score was associated with an increased risk of ischemic stroke (adjusted hazard ratio = 1.28, 95% confidence interval = 1.18-1.40, p < 0.001). Both maximum grade of stenosis and plaque vulnerability were not associated with incident ischemic stroke (all p > 0.05).

CONCLUSIONS

Neither the degree of carotid stenosis nor the presence of vulnerable plaques was associated with incident ischemic stroke in this cohort of individuals with AF. This suggests that carotid disease was probably not a significant contributor to ischemic stroke in this population.

Individual net clinical outcome with oral anticoagulation in atrial fibrillation using the ABC-AF risk scores

BACKGROUND

Decisions on stroke prevention strategies in patients with atrial fibrillation (AF) depend on the perceived risks of stroke and bleeding with different antithrombotic treatment strategies. The study objectives were to evaluate net clinical outcome with oral anticoagulation (OAC) for the individual patient with AF and to identify clinically relevant thresholds for OAC treatment.

METHODS

Patients with AF receiving OAC treatment in the randomized ARISTOTLE and RE-LY trials, with available biomarkers for calculation of ABC-AF scores at baseline, were included (n = 23,121). Observed 1-year risk on OAC was compared with predicted 1-year risk if the same patients would not have received OAC using the ABC-AF scores calibrated for aspirin. Net clinical outcome was defined as the sum of stroke and major bleeding risks.

RESULTS

The ratio between the 1-year incidence of major bleeding and stroke/systemic embolism events ranged from 1.4 to 10.6 according to different ABC-AF risk profiles. Net clinical outcome analyses showed that in patients with an ABC-AF-stroke risk >1% per year on OAC (>3% without OAC), treatment with OAC consistently provides larger net clinical benefit than no-OAC treatment. In patients with an ABC-AF-stroke risk <1.0% per year on OAC (<3% without OAC) an individualized balancing of risks regarding OAC or no-OAC treatment is needed.

CONCLUSIONS

In patients with AF, the ABC-AF risk scores allow an individual and continuous estimate of the balance between benefits and risks with OAC treatment. This precision medicine tool therefore seems useful as decision support and visualizes the net clinical benefit or harm with OAC treatment (http://www.abc-score.com/abcaf/).

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT00412984 (ARISTOTLE) and NCT00262600 (RE-LY).

Baseline brain imaging signs in patients with ischaemic stroke by the presence of atrial fibrillation: the ENCHANTED trial

BACKGROUND

We aimed to assess the association of atrial fibrillation (AF) on outcomes in a post hoc analysis of the ENCHANTED (Enhanced Control of Hypertension and Thrombolysis Stroke Study) and how this association is modified by baseline imaging features.

METHODS

Inverse probability of treatment weight was used to remove baseline imbalances between those with and without AF. The primary outcome was the modified Rankin Scale (mRS) scores at 90 days. Secondary outcomes were symptomatic intracerebral haemorrhage (sICH), early neurological deterioration or death within 24 h, and death at 90 days. The logistic regression model was used to determine the associations.

RESULTS

Of the 3285 patients included in this analysis, 636 (19%) had AF at baseline. Compared with non-AF, AF was not significantly associated with an unfavourable shift of mRS (odds ratio 1.09; 95% confidence interval, 0.96-1.24), but with sICH (2.82; 1.78-4.48; IST-3 criteria), early neurological deterioration or death within 24 h (1.31; 1.01-1.70), and death (1.42; 1.12-1.79). Among patients with acute ischaemic signs (presence, extent, swelling and attenuation of acute lesions), AF was associated with the increased risk of all the poor outcomes (all P < 0.04 for interaction).

CONCLUSIONS

We found AF increased risk of sICH, early neurological deterioration or death and death, but not unfavourable functional recovery at day 90 after thrombolysis in patients with AIS. The presence of acute ischaemic brain imaging signs at stroke presentation could be used to improve risk stratification in the presence of AF.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov (NCT01422616).

Trimethylamine-N-oxide is associated with cardiovascular mortality and vascular brain lesions in patients with atrial fibrillation

OBJECTIVE

Trimethylamine-N-oxide (TMAO) is a metabolite derived from the microbial processing of dietary phosphatidylcholine and carnitine and the subsequent hepatic oxidation. Due to its prothrombotic and inflammatory mechanisms, we aimed to assess its role in the prediction of adverse events in a susceptible population, namely patients with atrial fibrillation.

METHODS

Baseline TMAO plasma levels were measured by liquid chromatography-tandem mass spectrometry in 2379 subjects from the ongoing Swiss Atrial Fibrillation cohort. 1722 underwent brain MRI at baseline. Participants were prospectively followed for 4 years (Q1-Q3: 3.0-5.0) and stratified into baseline TMAO tertiles. Cox proportional hazards and linear and logistic mixed effect models were employed adjusting for risk factors.

RESULTS

Subjects in the highest TMAO tertile were older (75.4±8.1 vs 70.6±8.5 years, p<0.01), had poorer renal function (median glomerular filtration rate: 49.0 mL/min/1.73 m² (35.6-62.5) vs 67.3 mL/min/1.73 m² (57.8-78.9), p<0.01), were more likely to have diabetes (26.9% vs 9.1%, p<0.01) and had a higher prevalence of heart failure (37.9% vs 15.8%, p<0.01) compared with patients in the lowest tertile. Oral anticoagulants were taken by 89.1%, 94.0% and 88.2% of participants, respectively (from high to low tertiles). Cox models, adjusting for baseline covariates, showed increased total mortality (HR 1.65, 95% CI 1.17 to 2.32, p<0.01) as well as cardiovascular mortality (HR 1.86, 95% CI 1.21 to 2.88, p<0.01) in the highest compared with the lowest tertile. When present, subjects in the highest tertile had more voluminous, large, non-cortical and cortical infarcts on MRI (log-transformed volumes; exponentiated estimate 1.89, 95% CI 1.11 to 3.21, p=0.02) and a higher chance of small non-cortical infarcts (OR 1.61, 95% CI 1.16 to 2.22, p<0.01).

CONCLUSIONS

High levels of TMAO are associated with increased risk of cardiovascular mortality and cerebral infarction in patients with atrial fibrillation.

TRIAL REGISTRATION NUMBER

NCT02105844.

Development and Validation of a Postoperative Prognostic Nomogram to Predict Recurrence in Patients with Persistent Atrial Fibrillation: A Retrospective Cohort Study

Background: Patients with persistent atrial fibrillation (PsAF) have a high risk of recurrence after catheter radiofrequency ablation. Nevertheless, no effective prognostic tools have been developed to identify these high-risk patients to date. This study sought to develop and validate a simple linear predictive model for predicting postoperative recurrence in patients with PsAF.

Methods: From June 2013 to June 2021, patients with PsAF admitted to our hospital were enrolled in this single-center, retrospective, observational study. The characteristics substantially associated with recurrence in patients with PsAF were screened through univariate and multivariate logistic regression analysis. The receiver operating characteristic curve was used to assess the predictive significance of the nomogram model after nomogram development. Furthermore, to assess the clinical value of the nomogram, we performed calibration curve and decision curve analyses.

Results: A total of 209 patients were included in the study, 42 (20.10%) of whom were monitored up to 1 year for recurrent AF. The duration of AF episodes, left atrial diameter, BMI, CKMB, and alcohol consumption were found to be independent risk factors (P<0.05) and were integrated into the nomogram model development. The area under the curve was 0.895, the sensitivity was 93.3%, and the specificity was 71.4%, thus indicating the model’s excellent predictive ability. The C-index of the predictive nomogram model was 0.906. Calibration curve and decision curve analyses further revealed that the model had robust prediction and strong discrimination ability.

Conclusion: This simple, practical, and innovative nomogram can help clinicians in evaluation of the risk of PsAF recurrence after catheter ablation, thus facilitating preoperative evaluation, postoperative monitoring and ultimately the construction of more personalized therapeutic protocols.

Clinical Associations with the differences in rivaroxaban dosing in patients with atrial fibrillation stratified by three renal function formulae

Background

Clinical trials used Cockcroft-Gault (CG) formula to calculate the estimated glomerular filtration rate (eGFR) in order to dose rivaroxaban for patients with atrial fibrillation (AF).

Objectives

The aim of this study is to evaluate rivaroxaban dosing appropriateness in patients with AF with or without renal impairment based on the CG formula and other formulae, including Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation and the isotope dilution mass spectrometry (IDMS) traceable Modification of Diet in Renal Disease (MDRD) Study equation and the associated clinical outcomes.

Methodology

A retrospective cohort study conducted at Sultan Qaboos University Hospital (SQUH) from 1st January 2016 to 31st December 2020, included all adult patients (≥ 18 years) treated with rivaroxaban for AF and followed up for one year after starting the treatment.

Results

Based on the CG formula, the rivaroxaban dose was inappropriately prescribed in 27% of the patients (21% overdosed and 6% underdosed). Higher baseline creatinine (P=0.0014) and concurrent use of antiplatelet therapy (P<0.001) were associated with the tendency to rivaroxaban overdosing. Higher Body Mass Index (BMI) (P=0.002), female sex (P=0.032), and CKD (P=0.003) were associated with rivaroxaban underdosing. The degree of agreement between the renal function tests when comparing MDRD vs CG and CKD-EPI vs CG in terms of estimated glomerular filtration rate/creatine clearance (eGFR/CrCl) calculation was moderate (κ=0.46) and poor (κ=0.00), respectively, while, in terms of rivaroxaban dose appropriateness was almost perfect (κ=0.82) and substantial (κ=0.77). Clinical outcomes measured by stroke and bleeding events were not significantly different according to the appropriateness of the rivaroxaban dose.

Conclusion

This study has shown a relatively high consistency with the gold standard in dosing rivaroxaban in AF patients using CG formula. Treatment efficiency and safety were not affected by the proportion of dose inappropriateness found in this cohort.

Left Atrial Appendage Occlusion: Current Advances and Remaining Challenges

The field of left atrial appendage occlusion is rapidly evolving. However, several issues remain including the limited randomized efficacy data, peri-device leak, device-related thrombus, and the ongoing refinement of procedural techniques. In this article, we provide a contemporary overview of left atrial appendage occlusion focusing on 4 key remaining challenges: efficacy data, peri-device leak, device-related thrombus, and procedural optimization.

Vaspin Attenuates Atrial Abnormalities by Promoting ULK1/FUNDC1-Mediated Mitophagy

The worldwide incidence and prevalence of atrial fibrillation (AF) are increasing, making it a life-threatening condition due to the higher numbers of people suffering from obesity. Vaspin, an adipokine derived from epicardial adipose tissue, has been reported to reduce inflammation, inhibit apoptosis, and induce autophagy; however, its role in the pathogenesis of AF is not known. In this study, we investigated the role of vaspin in patients with AF and explored the molecular mechanisms using atrial myocytes in vitro. Our data showed that vaspin levels were significantly reduced in the plasma of patients with AF. Lower plasma levels of vaspin were also associated with a higher risk of AF in patients with obesity. Vaspin treatment in vitro alleviated cardiomyocyte injury, atrial fibrosis, atrial myocyte apoptosis, and mitochondrial injury in atrial myocytes following Ang-II stress. Moreover, our results demonstrated that vaspin protected against Ang-II-induced atrial myocyte dysfunction by inducing mitophagy. We also observed that vaspin treatment enhanced the phosphorylation of Fun14 domain-containing protein 1 (FUNDC1) at Ser17 by unc-51 like autophagy activating kinase 1 (ULK1), resulting in the induction of mitophagy. These positive effects of vaspin were reversed by ULK1 silencing in Ang-II-stimulated HL-1 cells. Our study is the first to propose that vaspin plays a vital role in AF pathogenesis via ULK1/FUNDC1-regulated mitophagy and could be a novel therapeutic target for AF.

The Impact of COVID-19 Pandemic on the Clinical Practice Patterns in Atrial Fibrillation: A Multicenter Clinician Survey in China

The COVID-19 pandemic has severely impacted healthcare systems worldwide. This study investigated cardiologists’ opinions on how the COVID-19 pandemic impacted clinical practice patterns in atrial fibrillation (AF). A multicenter clinician survey, including demographic and clinical questions, was administered to 300 cardiologists from 22 provinces in China, in April 2022. The survey solicited information about their treatment recommendations for AF and their perceptions of how the COVID-19 pandemic has impacted their clinical practice patterns for AF. The survey was completed by 213 cardiologists (71.0%) and included employees in tertiary hospitals (82.6%) and specialists with over 10 years of clinical cardiology practice (53.5%). Most respondents stated that there were reductions in the number of inpatients and outpatients with AF in their hospital during the pandemic. A majority of participants stated that the pandemic had impacted the treatment strategies for all types of AF, although to different extents. Compared with that during the assumed non-pandemic period in the hypothetical clinical questions, the selection of invasive interventional therapies (catheter ablation, percutaneous left atrial appendage occlusion) was significantly decreased (all p < 0.05) during the pandemic. There was no significant difference in the selection of non-invasive therapeutic strategies (the management of cardiovascular risk factors and concomitant diseases, pharmacotherapy for stroke prevention, heart rate control, and rhythm control) between the pandemic and non-pandemic periods (all p > 0.05). The COVID-19 pandemic has had a profound impact on the clinical practice patterns of AF. The selection of catheter ablation and percutaneous left atrial appendage occlusion was significantly reduced, whereas pharmacotherapy was often stated as the preferred option by participating cardiologists.

Left Atrial Appendage Occlusion, A Misnomer?: Where Do We Go From Here?

The importance of the left atrial appendage (LAA) as the source of thromboembolism including stroke in patients with nonvalvular atrial fibrillation is well documented, with more than 90% of ischemic strokes related to a LAA thrombus. Although oral anticoagulation has been the standard of care, approximately 50% to 60% of patients either have contraindications to oral anticoagulation or do not continue the medication beyond the first year. This led to the development of local site-specific therapy to occlude the LAA by either surgical or transcatheter means. Despite marked advancements, incomplete LAA closure with surgical and transcatheter approaches remains frequent. The etiology of incomplete LAA closure and its clinical implications remain unclear. Multiple strategies are in development including changes in deployment techniques, a new device design, and alternative approaches to leak closure.

Predicting cerebral infarction in patients with atrial fibrillation using machine learning: The Fushimi AF registry

The CHADS₂ and CHA₂DS₂-VASc scores are widely used to assess ischemic risk in the patients with atrial fibrillation (AF). However, the discrimination performance of these scores is limited. Using the data from a community-based prospective cohort study, we sought to construct a machine learning-based prediction model for cerebral infarction in patients with AF, and to compare its performance with the existing scores. All consecutive patients with AF treated at 81 study institutions from March 2011 to May 2017 were enrolled (n = 4396). The whole dataset was divided into a derivation cohort (n = 1005) and validation cohort (n = 752) after excluding the patients with valvular AF and anticoagulation therapy. Using the derivation cohort dataset, a machine learning model based on gradient boosting tree algorithm (ML) was built to predict cerebral infarction. In the validation cohort, the receiver operating characteristic area under the curve of the ML model was higher than those of the existing models according to the Hanley and McNeil method: ML, 0.72 (95%CI, 0.66-0.79); CHADS₂, 0.61 (95%CI, 0.53-0.69); CHA₂DS₂-VASc, 0.62 (95%CI, 0.54-0.70). As a conclusion, machine learning algorithm have the potential to perform better than the CHADS₂ and CHA₂DS₂-VASc scores for predicting cerebral infarction in patients with non-valvular AF.

The Heart Brain Team and Patient-Centered Management of Ischemic Stroke

The multifaceted connections between the heart and the brain have been extensively studied at the anatomy, pathophysiology, and clinical levels. Studies have suggested a vital role for both cardiologists and neurologists in the management of various cardiovascular and neurological disorders. However, a true heart-brain team-based approach remained confined to large, specialized centers. In this paper, we review the various intersection areas of cardiology and neurology with regard to ischemic stroke. We focus our discussion on the challenges and opportunity for a heart-team approach to stroke in the context of atrial fibrillation, carotid disease, and patent foramen ovale, and in the setting of strokes complicating transcatheter endovascular interventions.

Prophylactic anticoagulation in sinus rhythm for stroke prevention in cardiovascular disease: contemporary meta-analysis of large randomized trials

AIMS

Anticoagulation with non-vitamin K oral anticoagulants (NOACs) to prevent stroke is a mainstay of atrial fibrillation (AF) management. However, multiple cardiovascular diseases (CVDs) are associated with elevated ischaemic stroke risk even in sinus rhythm. In this meta-analysis, we assess efficacy and safety of prophylactic NOAC agents for stroke prevention in patients without AF.

METHODS AND RESULTS

A search was conducted for randomized controlled trials (RCTs) that evaluated an NOAC and control drug (placebo or antiplatelet) in non-AF patients with mixed CVD. The primary efficacy and safety outcomes were ischaemic stroke and major bleeding, respectively. Results were stratified based on primary- and mini-NOAC doses. Thirteen RCTs were identified with a total of 89 383 patients with CVD in sinus rhythm (53 778 on NOAC, 35 605 on control drug; mean age 65.5 ± 2.7 years). Over a mean follow-up of 18.3 months, 1429 (1.6%) ischaemic strokes occurred. Use of NOAC was associated with 26% reduction in stroke [odds ratio (OR) 0.74, 95% confidence interval (CI) 0.62-0.87; 1.1 vs. 1.8 events per 100 person-years], with numbers needed to treat of 153 patients to prevent one stroke. Major bleeding was increased with NOAC (OR 1.74, 95% CI 1.44-2.09; 2.1 vs. 1.0 events per 100 person-years). The weighted net clinical benefit (wNCB, composite of ischaemic stroke and bleeding) did not suggest a favourable effect with any NOAC dose (wNCB for primary-dose: -0.35; mini-dose: -0.06).

CONCLUSION

Current evidence does not support use of NOACs for stroke prevention in non-AF CVD population as risk of major bleeding still exceeds ischaemic stroke benefit.

Perceptions and knowledge gaps on CHA2DS2-VASc score components: a joint survey of Chinese clinicians and clinical pharmacists

BACKGROUND

The CHA₂DS₂-VASc score is a guideline-recommended stroke risk stratification scheme for patients with atrial fibrillation (AF). Accurately calculating the CHA₂DS₂-VASc score and recognizing the stroke risk in AF patients is the foundation of optimal anticoagulation therapy. This survey aims to obtain a comprehensive understanding of perceptions and knowledge gaps on CHA₂DS₂-VASc scores among Chinese medical professionals for future education programs.

METHODS

A cross-sectional survey was conducted among clinicians, including cardiologists, neurologists, emergency physicians (EPs), general practitioners (GPs) and clinical pharmacists (CPs) using a self-administered questionnaire on the Chinese mainland. The survey contained 21 questions in combination with single-choice questions, multiple-choice questions, and an open-ended question, which was distributed online via e-mail or social media.

RESULTS

A total of 562 participants (40.9% cardiologists, 19.2% neurologists, 8.5% EPs, 10.3% GPs, and 21.0% CPs) completed the survey. Most respondents across all specialties reported skills requiring improvements in the CHA₂DS₂-VASc score. In general, cardiologists, neurologists, and CPs had a relatively better understanding than GPs and EPs about the application of CHA₂DS₂-VASc score. Considering 'H' and 'D' components, more than 90% of respondents chose the correct answer in single-choice questions, whereas the correctness rate declined concerning detailed scoring criteria. Regarding 'C,' 'A₂,' 'S₂,' and 'V' components, partly correct answers were commonly observed in most multiple-choice questions. The majority of cardiologists believed themselves to be very familiar or at least familiar with the score and its components, while around 70% of EPs and GPs felt relatively unfamiliar with the CHA₂DS₂-VASc score. Mobile apps, AF guidelines and notebooks/handbooks were popular referencing scoring tools for respondents.

CONCLUSIONS

Chinese medical professionals, especially EPs and GPs, revealed a lack of knowledge and insufficient skills for CHA₂DS₂-VASc scores and their components. Improvements in the awareness of the CHA₂DS₂-VASc score and its detailed scoring criteria are urgently needed for Chinese medical professionals. Therefore, education programs concerning the introduction of stroke risk evaluation for AF patients and the development of referencing scoring tools are necessary.

Prognostic relevance of normocytic anemia in elderly patients affected by cardiovascular disease

BACKGROUND

Anemia associated with cardiovascular diseases (CVD) is a common condition in older persons. Prevalence and prognostic role of anemia were extensively studied in patients with myocardial infarction (MI) or congestive heart failure (CHF) whereas limited data were available on patients with atrial fibrillation (AF). This study was conducted to assess the clinical prevalence and prognostic relevance of anemia in elderly patients affected by AF and other CVDs.

METHODS

A total of 866 elderly patients (430 men and 436 women, age: 65-98 years, mean age: 85 ± 10 years) were enrolled. Among these patients, 267 patients had acute non-ST-segment elevation MI (NSTEMI), 176 patients had acute CHF, 194 patients had acute AF and 229 patients were aged-matched healthy persons (CTR). All parameters were measured at the hospital admission and cardiovascular mortality was assessed during twenty-four months of follow-up.

RESULTS

The prevalence of anemia was higher in NSTEMI, CHF and AF patients compared to CTR subjects (50% vs. 15%, P < 0.05), with normocytic anemia being the most prevalent type (90%). Adjusted mortality risk was higher in anemic patient versus non-anemic patient in all the groups of patients [NSTEMI: hazard ratio (HR) = 1.81, 95% CI: 1.06-2.13; CHF: HR = 2.49, 95% CI: 1.31-4.75; AF: HR = 1.98, 95% CI: 1.01-3.88]. Decreased hemoglobin levels ( P = 0.001) and high reticulocyte index (P = 0.023) were associated with higher mortality in CVD patients.

CONCLUSIONS

The significant associations between CVD and anemia and the prognostic relevance of anemia for elderly patients with CVD were confirmed in this study. The presence of anemia in AF patients is associated with a two-fold increased mortality risk compared with non-anemic AF patients. Low hemoglobin and high reticulocyte count independently predict mortality in elderly patients with CVD.

A meta-analysis of clinical risk factors for stroke in anticoagulant-naïve patients with atrial fibrillation

AIMS

The aim of this study is to summarize data from prospective cohort studies on clinical predictors of stroke and systemic embolism in anticoagulant-naïve atrial fibrillation (AF) patients.

METHODS AND RESULTS

EMBASE, MEDLINE, Global Index Medicus, and Web of Science were searched to identify all studies published by 28 November 2019. Forty-seven studies reporting data from 1 756 984 participants in 15 countries were included. The pooled incidence of stroke in anticoagulant-naïve AF patients was 23.8 per 1000 person-years (95% CI 19.7-28.2). Older age was associated with incident stroke or systemic embolism, with a pooled hazard ratio (HR) of 2.14 (95% CI 1.85-2.47), 2.83 (95% CI 2.27-3.51), and 6.87 (95% CI 6.33-7.44) for age 65-75, ≥75, and ≥85 years, respectively. Other predictors of stroke or systemic embolism included history of stroke or TIA (HR 2.84, 95% CI 2.19-3.67), hypertension (HR 1.60, 95% CI 1.37-1.86), diabetes (HR 1.28, 95% CI 1.20-1.37), heart failure (HR 1.25, 95% CI 1.11-1.40), peripheral artery disease (pooled HR 1.35, 95% CI 1.04-1.75), vascular disease (pooled HR 1.21, 95% CI 1.06-1.39), and prior myocardial infarction (pooled HR 1.08, 95% CI 1.03-1.14). Female sex was a predictor of thromboembolism in studies outside Asia (HR 1.33, 95% CI 1.15-1.55), but not in those done in Asia (HR 0.95, 95% CI 0.81-1.10).

CONCLUSION

This study confirms age and prior stroke as the strongest predictors of stroke or systemic embolism in anticoagulant-naive AF patients. Other predictors include hypertension, diabetes, heart failure, and vascular disease. Female sex seems not to be universally associated with stroke or systemic embolism.

Secondary Stroke Prevention Following Embolic Stroke of Unknown Source in the Absence of Documented Atrial Fibrillation: A Clinical Review

Approximately one-third of ischemic strokes are classified as cryptogenic strokes. The risk of stroke recurrence in these patients is significantly elevated with up to one-third of patients with cryptogenic stroke experiencing a further stroke within 10 years. While anticoagulation is the mainstay of treatment for secondary stroke prevention in the context of documented atrial fibrillation (AF), it is estimated that up to 25% of patients with cryptogenic stroke have undiagnosed AF. Furthermore, the historical acceptance of a causal relationship between AF and stroke has recently come under scrutiny, with evidence to suggest that embolic stroke risk may be elevated even in the absence of documented atrial fibrillation attributable to the presence of electrical and structural changes constituting an atrial cardiomyopathy. More recently, the term embolic stroke of unknown source has garnered increasing interest as a subset of patients with cryptogenic stroke in whom a minimum set of diagnostic investigations has been performed, and a nonlacunar infarct highly suspicious of embolic etiology is suspected but in the absence of an identifiable secondary cause of stroke. The ongoing ARCADIA (Atrial Cardiopathy and Antithrombotic Drugs in Prevention After Cryptogenic Stroke) randomized trial and ATTICUS (Apixiban for Treatment of Embolic Stroke of Undetermined Source) study seek to further define this novel term. This review summarizes the relationship between AF, embolic stroke, and atrial cardiomyopathy and provides an overview of the clinical relevance of cardiac imaging, electrocardiographic, and serum biomarkers in the assessment of AF and secondary stroke risk. The implications of these findings on therapeutic considerations is considered and gaps in the literature identified as areas for future study in risk stratifying this cohort of patients.

A Review of Biomarkers for Ischemic Stroke Evaluation in Patients With Non-valvular Atrial Fibrillation

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia worldwide and results in a significantly increased ischemic stroke (IS) risk. IS risk stratification tools are widely being applied to guide anticoagulation treatment decisions and duration in patients with non-valvular AF (NVAF). The CHA₂DS₂-VASc score is largely validated and currently recommended by renowned guidelines. However, this score is heavily dependent on age, sex, and comorbidities, and exhibits only moderate predictive power. Finding effective and validated clinical biomarkers to assist in personalized IS risk evaluation has become one of the promising directions in the prevention and treatment of NVAF. A number of studies in recent years have explored differentially expressed biomarkers in NVAF patients with and without IS, and the potential role of various biomarkers for prediction or early diagnosis of IS in patients with NVAF. In this review, we describe the clinical application and utility of AF characteristics, cardiac imaging and electrocardiogram markers, arterial stiffness and atherosclerosis-related markers, circulating biomarkers, and novel genetic markers in IS diagnosis and management of patients with NVAF. We conclude that at present, there is no consensus understanding of a desirable biomarker for IS risk stratification in NVAF, and enrolling these biomarkers into extant models also remains challenging. Further prospective cohorts and trials are needed to integrate various clinical risk factors and biomarkers to optimize IS prediction in patients with NVAF. However, we believe that the growing insight into molecular mechanisms and in-depth understanding of existing and emerging biomarkers may further improve the IS risk identification and guide anticoagulation therapy in patients with NVAF.

Direct Oral Anticoagulants in Asian Patients with Atrial Fibrillation: Consensus Recommendations by the Asian Pacific Society of Cardiology on Strategies for Thrombotic and Bleeding Risk Management

The disease burden of AF is greater in Asia-Pacific than other areas of the world. Direct oral anticoagulants (DOACs) have emerged as effective alternatives to vitamin K antagonists (VKA) for preventing thromboembolic events in patients with AF. The Asian Pacific Society of Cardiology developed this consensus statement to guide physicians in the management of AF in Asian populations. Statements were developed by an expert consensus panel who reviewed the available data from patients in Asia-Pacific. Consensus statements were developed then put to an online vote. The resulting 17 statements provide guidance on the assessment of stroke risk of AF patients in the region, the appropriate use of DOACs in these patients, as well as the concomitant use of DOACs and antiplatelets, and the transition to DOACs from VKAs and vice versa. The periprocedural management of patients on DOAC therapy and the management of patients with bleeding while on DOACs are also discussed.

Oral Anticoagulation Use in High-Risk Patients Is Improved by Elimination of False-Positive and Inactive Atrial Fibrillation Cases

BACKGROUND

Multiple registries have reported that >40% of high-risk atrial fibrillation patients are not taking oral anticoagulants. The purpose of our study was to determine the presence or absence of active atrial fibrillation and CHA₂DS₂-VASc (Congestive heart failure, Hypertension, Age ≥75 y, Diabetes mellitus, prior Stroke [or transient ischemic attack or thromboembolism], Vascular disease, Age 65-74 y, Sex category) risk factors to accurately identify high-risk atrial fibrillation (CHA₂DS₂-VASc ≥2) patients requiring oral anticoagulants and the magnitude of the anticoagulant treatment gap.

METHODS

We retrospectively adjudicated 6514 patients with atrial fibrillation documented by at least one of: billing diagnosis, electronic medical record encounter diagnosis, electronic medical record problem list, or electrocardiogram interpretation.

RESULTS

After review, 4555/6514 (69.9%) had active atrial fibrillation, while 1201 had no documented history of atrial fibrillation and 758 had a history of atrial fibrillation that was no longer active. After removing the 1201 patients without a confirmed atrial fibrillation diagnosis, oral anticoagulant use in high-risk patients increased to 71.1% (P < .0001 compared with 62.9% at baseline). Oral anticoagulant use increased to 79.7% when the 758 inactive atrial fibrillation patients were also eliminated from the analysis (P < .0001 compared with baseline). In the active high-risk atrial fibrillation group, there was no significant difference in the use of oral anticoagulants between men (80.7%) and women (78.8%) with a CHA₂DS₂-VASc ≥2, or in women with a CHA₂DS₂-VASc ≥3 (79.9%).

CONCLUSIONS

Current registries and health system health records with unadjudicated diagnoses over-report the number of high-risk atrial fibrillation patients not taking oral anticoagulants. Expert adjudication identifies a smaller treatment gap than previously described.

A simple and easily implemented risk model to predict 1-year ischemic stroke and systemic embolism in Chinese patients with atrial fibrillation

Background:

Accurate prediction of ischemic stroke is required for deciding anticoagulation use in patients with atrial fibrillation (AF). Even though only 6% to 8% of AF patients die from stroke, about 90% are indicated for anticoagulants according to the current AF management guidelines. Therefore, we aimed to develop an accurate and easy-to-use new risk model for 1-year thromboembolic events (TEs) in Chinese AF patients.

Methods:

From the prospective China Atrial Fibrillation Registry cohort study, we identified 6601 AF patients who were not treated with anticoagulation or ablation at baseline. We selected the most important variables by the extreme gradient boosting (XGBoost) algorithm and developed a simplified risk model for predicting 1-year TEs. The novel risk score was internally validated using bootstrapping with 1000 replicates and compared with the CHA₂DS₂-VA score (excluding female sex from the CHA₂DS₂-VASc score).

Results:

Up to the follow-up of 1 year, 163 TEs (ischemic stroke or systemic embolism) occurred. Using the XGBoost algorithm, we selected the three most important variables (congestive heart failure or left ventricular dysfunction, age, and prior stroke, abbreviated as CAS model) to predict 1-year TE risk. We trained a multivariate Cox regression model and assigned point scores proportional to model coefficients. The CAS scheme classified 30.8% (2033/6601) of the patients as low risk for TE (CAS score = 0), with a corresponding 1-year TE risk of 0.81% (95% confidence interval [CI]: 0.41%–1.19%). In our cohort, the C-statistic of CAS model was 0.69 (95% CI: 0.65–0.73), higher than that of CHA₂DS₂-VA score (0.66, 95% CI: 0.62–0.70, Z = 2.01, P = 0.045). The overall net reclassification improvement from CHA₂DS₂-VA categories (low = 0/high ≥1) to CAS categories (low = 0/high ≥1) was 12.2% (95% CI: 8.7%–15.7%).

Conclusion:

In Chinese AF patients, a novel and simple CAS risk model better predicted 1-year TEs than the widely-used CHA₂DS₂-VA risk score and identified a large proportion of patients with low risk of TEs, which could potentially improve anticoagulation decision-making.

Trial Registration:

www.chictr.org.cn (Unique identifier No. ChiCTR-OCH-13003729).

Stroke risk associated with carotid and aortic atherosclerosis in patients with atrial fibrillation: A systematic review

OBJECTIVE

This review aimed to summarize the evidence on the risk of thromboembolism associated with carotid and aortic atherosclerosis in patients with AF, and the potential impact of their inclusion in current stroke risk stratification scores.

METHODS

MEDLINE, Web of Science and EMBASE were systematically searched to identify all published studies providing relevant data through 28 February 2021.

RESULTS

We identified 10 eligible studies. There was high heterogeneity across studies, precluding a meta-analysis. Carotid stenosis was not associated with incident ischemic stroke in three prospective studies, including the SPAF II trial and the ROCKET-AF trial. An association between carotid stenosis and thromboembolism was found in two studies, with a potential reporting bias due to their retrospective design. The evidence suggesting that carotid plaque predicts stroke or transient ischemic attack in AF patients were more consistent in the four studies evaluating this association. The inclusion of carotid plaque and carotid intima-media thickness (cIMT) into stroke risk stratification tools for AF patients improved their performance. Data on the association of aortic plaque with thromboembolism is scarce in patients with AF. The two studies reporting on this association suggest that aortic plaque alone does not predict incident ischemic stroke.

CONCLUSION

Available data suggest an association of carotid atherosclerosis with the risk of stroke and transient ischemic attack in patients with AF. Future studies should evaluate whether incorporating cIMT and characteristics of carotid and aortic plaques into scoring systems would improve stroke prediction and prevention in patients with AF.

KLF15 Loss-of-Function Mutation Underlying Atrial Fibrillation as well as Ventricular Arrhythmias and Cardiomyopathy

Atrial fibrillation (AF) represents the most common type of clinical cardiac arrhythmia and substantially increases the risks of cerebral stroke, heart failure and death. Accumulating evidence has convincingly demonstrated the strong genetic basis of AF, and an increasing number of pathogenic variations in over 50 genes have been causally linked to AF. Nevertheless, AF is of pronounced genetic heterogeneity, and the genetic determinants underpinning AF in most patients remain obscure. In the current investigation, a Chinese pedigree with AF as well as ventricular arrhythmias and hypertrophic cardiomyopathy was recruited. Whole exome sequencing and bioinformatic analysis of the available family members were conducted, and a novel heterozygous variation in the KLF15 gene (encoding Krüppel-like factor 15, a transcription factor critical for cardiac electrophysiology and structural remodeling), NM_014079.4: c.685A>T; p.(Lys229*), was identified. The variation was verified by Sanger sequencing and segregated with autosomal dominant AF in the family with complete penetrance. The variation was absent from 300 unrelated healthy subjects used as controls. In functional assays using a dual-luciferase assay system, mutant KLF15 showed neither transcriptional activation of the KChIP2 promoter nor transcriptional inhibition of the CTGF promoter, alone or in the presence of TGFB1, a key player in the pathogenesis of arrhythmias and cardiomyopathies. The findings indicate KLF15 as a new causative gene responsible for AF as well as ventricular arrhythmias and hypertrophic cardiomyopathy, and they provide novel insight into the molecular mechanisms underlying cardiac arrhythmias and hypertrophic cardiomyopathy.

Utility of the CHA2DS2-VASc score for predicting ischaemic stroke in patients with or without atrial fibrillation: a systematic review and meta-analysis

AIMS

Anticoagulants are the mainstay treatment for stroke prevention in patients with non-valvular atrial fibrillation (NVAF), and the CHA2DS2-VASc score is widely used to guide anticoagulation therapy in this cohort. However, utility of CHA2DS2-VASc in NVAF patients is debated, primarily because it is a vascular scoring system, which does not incorporate atrial fibrillation related parameters. Therefore, we conducted a meta-analysis to estimate the discrimination ability of CHA2DS2-VASc in predicting ischaemic stroke overall, and in subgroups of patients with or without NVAF.

METHODS AND RESULTS

PubMed and Embase databases were searched till June 2020 for published articles that assessed the discrimination ability of CHA2DS2-VASc, as measured by C-statistics, during mid-term (2-5 years) and long-term (>5 years) follow-up. Summary estimates were reported as random effects C-statistics with 95% confidence intervals (CIs). Seventeen articles were included in the analysis. Nine studies (n = 453 747 patients) reported the discrimination ability of CHA2DS2-VASc in NVAF patients, and 10 studies (n = 138 262 patients) in patients without NVAF. During mid-term follow-up, CHA2DS2-VASc predicted stroke with modest discrimination in the overall cohort [0.67 (0.65-0.69)], with similar discrimination ability in patients with NVAF [0.65 (0.63-0.68)] and in those without NVAF [0.69 (0.68-0.71)] (P-interaction = 0.08). Similarly, at long-term follow-up, CHA2DS2-VASc had modest discrimination [0.66 (0.63-0.69)], which was consistent among patients with NVAF [0.63 (0.54-0.71)] and those without NVAF [0.67 (0.64-0.70)] (P-interaction = 0.39).

CONCLUSION

This meta-analysis suggests that the discrimination power of the CHA2DS2-VASc score in predicting ischaemic stroke is modest, and is similar in the presence or absence of NVAF. More accurate stroke prediction models are thus needed for the NVAF population.

Biomarkers in Atrial Fibrillation: Pathogenesis and Clinical Implications

Biomarkers derived from the key components of the pathophysiology of atrial fibrillation (AF) and its complications have the potential to play an important role in earlier characterization of AF phenotype and in risk prediction of adverse clinical events, which may translate into improved management strategies. C-reactive protein, natriuretic peptides, cardiac troponins, growth differentiation factor-15, and fibroblast growth factor-23 have been shown to be the most promising biomarkers in AF. Some biomarkers have already been included in clinical risk scores to predict postoperative AF, thromboembolism, major bleeding, and death. Considerably more work is needed to bring these novel biomarkers into routine clinical management of patients with AF.