Stroke risk assessment in atrial fibrillation: risk factors and markers of atrial myopathy

Impact of Sorbs2 dysfunction on cardiovascular diseases

Despite significant advancements in prevention and treatment over the past decades, cardiovascular diseases (CVDs) remain the leading cause of death worldwide. CVDs involve multifactorial inheritance, but our understanding of the genetic impact on these diseases is still incomplete. Sorbin and SH3 domain-containing protein 2 (Sorbs2) is ubiquitously expressed in various tissues, including the cardiovascular system. Increasing evidence suggests that Sorbs2 malfunction contributes to CVDs. This manuscript will review our current understanding of the potential mechanisms underlying Sorbs2 dysregulation in the development of CVDs.

Left Atrial Size and Left Atrial Volume Index as Predictors of Atrial High-Rate Episodes

BACKGROUND

Recent studies have shown that atrial high-rate episodes (AHREs) are associated with adverse cardiovascular outcomes, including an increased risk of stroke, cardiovascular mortality, and future atrial fibrillation. Despite efforts to identify predictors for AHRE, the relationship between left atrial morphology and AHRE remains unclear.

METHODS

We systematically reviewed MEDLINE and EMBASE from inception to May 2024 to assess the association between left atrial morphology, measured as left atrial diameter (mm) and left atrial volume index (LAVI, mL/m2) via transthoracic echocardiography, and the occurrence of AHRE in patients without a prior history of atrial fibrillation at device implantation. Means and standard deviations of LAD and LAVI were extracted to calculate pooled mean differences using the generic inverse variance method.

RESULTS

A total of 18 cohort studies were included in the meta-analysis. The results showed that patients with AHRE had significantly higher left atrial diameter and LAVI compared to those without AHRE. The pooled mean difference for left atrial diameter was 2.19 mm (95% CI: 1.11-3.28; I2 = 80%, p < 0.001), while for LAVI, it was 4.88 mL/m2 (95% CI: 2.55-7.21; I2 = 55%, p < 0.001).

CONCLUSIONS

Our study demonstrated that patients with AHRE had greater left atrial diameter and LAVI than those without AHRE. Further research is needed to clarify the underlying mechanism.

Usefulness of two-dimensional speckle tracking echocardiography in assessment of left atrial fibrosis degree and its application in atrial fibrillation

This study aimed to establish a clinical prediction model for assessing the degree of left atrial fibrosis (LAF) in patients with atrial fibrillation (AF) by combining two-dimensional speckle tracking echocardiography (2D-STE). Additionally, the study sought to evaluate the predictive utility of 2D-STE for left atrial appendage thrombosis (LAAT) and the recurrence of AF after radiofrequency catheter ablation (RFA). A total of 195 patients with AF were included, and late gadolinium enhanced cardiac magnetic resonance was adopted to assess LAF degree. Fibrotic tissue as a percentage of total left atrial wall volume > 20% was defined as severe LAF. Echocardiographic parameters were obtained and analyzed using 2D-STE. The patients were randomly divided into two cohorts (7:3) as the training and testing cohorts. Independent predictors of severe LAF were determined via univariate and multivariate logistic regression, including age, CHA2DS2-VA score, left atrial appendage emptying fraction (LAA-EF), peak atrial longitudinal strain (PALS), left atrial stiffness index (LASI), left atrial strain during contraction phase (LASct) and left atrial strain during conduit phase (LAScd). The nomogram was established with the above variables and the area under the curve of the nomogram in testing cohorts was 0.89 (95% CI, 0.80-0.98). As validated by receiver operating characteristic curves, calibration curves and decision curve analysis, the nomogram model demonstrated promising potential for clinical application. Besides, by univariate and multivariate logistic regression analyses, CHA2DS2-VA score, uric acid, LAA-EF, left atrial appendage peak blood flow emptying velocity (LAA-PEV) and LASct were found to be independent predictors of LAAT, and left atrial appendage length, E/e' and LASct were found to be independent predictors of post-ablation AF recurrence. 2D-STE can be applied to evaluate LAF degree of AF patients and predict LAAT and AF recurrence.

Quantification of atrial cardiomyopathy disease severity by electroanatomic voltage mapping and cardiac magnetic resonance imaging

INTRODUCTION

Atrial late gadolinium enhancement (Atrial-LGE) and electroanatomic voltage mapping (Atrial-EAVM) quantify the anatomical and functional extent of atrial cardiomyopathy. We aimed to explore the relationships between, and outcomes from, these modalities in patients with atrial fibrillation undergoing ablation.

METHODS

Patients undergoing first-time ablation had disease severities quantified using both Atrial-LGE and Atrial-EAVM. Correlations between modalities and their relationships with clinical features and arrhythmia recurrence were assessed.

RESULTS

In 123 atrial fibrillation patients (60 ± 10 years), Atrial-EAVM was moderately correlated with Atrial-LGE (r = .34, p < .001), with a mean fibrosis burden of 47.2% ± 14.91%. Agreement was strongest in the highest tertile of fibrosis burden (mean of differences 16.8% (95% CI = -24.4% to 57.9%, p = .433). Fibrosis burden was greater for Atrial-LGE than Atrial-EAVM (50.7% ± 10.7% vs. 13.7% ± 7.13%, p < .005) for patients in the lowest tertile who were younger, had smaller atria and a greater frequency of paroxysmal atrial fibrillation. Both Atrial EAVM and Atrial LGE were associated with recurrence of arrhythmia following ablation (Atrial-LGE HR = 1.02 (95% CI = 1.01-1.04), p = .047; Atrial-EAVM HR = 1.02 (95% CI = 1.005-1.03), p = .007). A low fibrosis burden (<15%) by Atrial-EAVM identified patients with very low arrhythmia recurrence. In contrast, a much higher fibrosis burden (>66%) by Atrial-LGE identified patients failing to respond to ablation.

CONCLUSIONS

We demonstrate for the first time that the level of agreement between Atrial-EAVM and Atrial-LGE is dependent on the level of atrial cardiomyopathy disease severity. The functional consequences of atrial cardiomyopathy are most evident in patients with the highest anatomical extent of disease.

The Predictive Value of Circulating Gal-3 for New Stroke Events in Paroxysmal Atrial Fibrillation Patients Despite Oral Anticoagulation Medications

BACKGROUND

CHA2DS2-VASc is used to assess the risk of stroke in patients with atrial fibrillation (AF) and guide anticoagulant treatment decisions, but it has limitations in accurately predicting stroke risk in individual patients. The objective of this study is to conduct a cohort study by assessing preoperative levels of Gal-3 in paroxysmal AF patients, aiming to observe its correlation with the subsequent incidence of stroke events.

METHOD

This study enrolled 197 patients with nonvalvular paroxysmal AF. Blood samples were taken to test Gal-3 levels. All patients were followed up for 4 years after admission.

RESULTS

Compared to the nonstroke cases, serum levels of Gal-3 were markedly elevated in stroke cases (7.08 [IQR, 4.60-10.96] vs. 17.34 [IQR, 8.28-20.31], p < 0.001). Gal-3 yields a superior AUC (0.748, with a 95%CI of 0.681-0.807) compared to other classical stroke indices, such as BNP, CHA2DS2-Vas score, and TNI. Remarkably, the Gal-3 index exhibited a superior predictive capacity, yielding a significant incremental predictive value that surpassed the conventional risk factors (CHA2DS2-VASc score) for stroke events, as evidenced by an IDI of 16.4% (p < 0.001) and an NRI of 34.7% (p = 0.002).

CONCLUSION

The presence of Gal-3 is an independent risk factor for stroke in patients with AF. Elevated levels of Gal-3 have the potential to serve as a valuable biomarker for identifying incident strokes in AF patients. Furthermore, incorporating the assessment of Gal-3 levels into the conventional CHA2DS2-VASc score could significantly enhance its predictive accuracy for stroke in AF patients.

Association between triglyceride glucose index and adverse cardiovascular prognosis in patients with atrial fibrillation without diabetes: a retrospective cohort study

BACKGROUND

Atrial fibrillation (AF) is the most prevalent arrhythmia encountered in clinical practice. Triglyceride glucose index (Tyg), a convenient evaluation variable for insulin resistance, has shown associations with adverse cardiovascular outcomes. However, studies on the Tyg index's predictive value for adverse prognosis in patients with AF without diabetes are lacking.

METHODS

This retrospective study utilized electronic medical records to collect data on patients with AF hospitalized at West China Hospital from January to June 2020. Participants were categorized into three groups based on their Tyg index levels. The primary outcome, major adverse cardiovascular events, included cardiac death, stroke, and myocardial infarction. Kaplan-Meier curve, Cox proportional hazards regression model, and restricted cubic spline were employed to explore the relationship between the Tyg index and outcomes. The predictive performance of the CHA2DS2-VASc model was evaluated after incorporating the Tyg index.

RESULTS

The study comprised 864 participants (mean age 67.69 years, 55.32% male, 57.52% paroxysmal AF). Patients with high Tyg index had a significantly higher risk of developing major adverse cardiovascular events (MACE) (P < 0.001, hazard ratio: 2.05, 95% confidence interval:1.65-2.56). The MACE risk in the middle Tyg group was similar to that in the low Tyg group (P = 0.1) during the 48-month follow-up period. However, focusing on the last 24 months revealed a higher MACE risk (P = 0.015) in the middle Tyg group. The restricted cubic spline analysis revealed an S-shaped correlation between Tyg and MACE. The CHA2DS2-VASc model combined with the Tyg index showed improved predictive performance and net benefit.

CONCLUSIONS

A high Tyg index is associated with poorer prognosis in patients with AF without diabetes. Integrating the Tyg index into the CHA2DS2-VASc model may enhance its predictive performance, offering clinical utility.

Epigenetic regulation on left atrial function and disease recurrence after catheter ablation in atrial fibrillation

BACKGROUND

Genetic variation and modifiable risk factors play a significant role in the pathogenesis of atrial fibrillation (AF). The influence of epigenetic modification on AF remains to be elucidated. We investigated the role of DNA methylation in the etiology of AF. Epigenetic evaluation was performed in 115 AF patients who underwent radiofrequency catheter ablation in a single institution. We measured methylation at approximately 850,000 bp cytosine-phosphate-guanine (CpG) sites in the 115 samples. The degree of methylation was compared across seven classification criteria: type of AF, late recurrence, impaired left atrium (LA) function, late gadolinium enhancement, LA diameter, LA volume, and flow velocity of the LA appendage.

RESULTS

The four most significantly methylated genes were DEFB104B, C3, TANC1, and TMEM9B. The DEFB104B gene (cg20223677 in the transcription start site), which encodes β-defensin 104B, was hypomethylated in three groups: AF patients with late recurrence, impaired LA function, and impaired LAA flow velocity. Enriched functional annotation of the differentially methylated datasets revealed that five out of the seven AF groups in this cohort were associated with genes involved in the cell movement of endothelial cell lines, sprouting angiogenesis by endothelial cell lines, or migration of endothelial cell lines.

CONCLUSIONS

Epigenetic profiling revealed that epigenetic modification might affect important characteristics of AF. Our results suggest that the pathogenesis of AF might be affected by not only genetic variation or modifiable factors but also by epigenetic modulation.

Beyond Anticoagulation: Limitations of Oral Anticoagulants in Preventing Stroke Recurrence in Atrial Fibrillation

Background/Objectives: Despite the widespread use of oral anticoagulants (OACs), acute ischemic stroke (AIS) remains a significant risk for patients with atrial fibrillation (AF). The real-world effectiveness of OACs in preventing recurrent strokes, particularly following an initial stroke of cardioembolic (CE) origin, continues to be a major challenge for clinicians managing AF patients. This study evaluated the efficacy of OACs in secondary stroke prevention and investigated the influence of anticoagulation type and quality on recurrence risk. Methods: We analyzed data from 128 AF patients in the prospective Transzlációs Idegtudományi Nemzeti Laboratórium (TINL) STROKE-registry, admitted with CE stroke between February 2023 and September 2024. Patients were categorized by anticoagulation status at admission (OAC-users, n = 89; anticoagulation-naïve, n = 39). Recurrence rates were assessed using logistic regression models, adjusted for age, sex, hypertension, diabetes, and pre-stroke disability. Subgroup analyses explored the effects of anticoagulation type and quality. Results: Recurrence rates were similar between the OAC-treated and anticoagulation-naïve patients after adjusting for confounders (19.10% vs. 17.95%, p = 0.870). Among the anticoagulated patients, neither anticoagulation type nor quality alone significantly influenced the recurrence risk. However, their interaction was statistically significant (p = 0.049), suggesting that the effectiveness of anticoagulation in preventing strokes is strongly affected by treatment quality. Conclusions: Although OACs are a cornerstone of stroke prevention in patients with AF, their efficacy in reducing recurrence depends on optimal management. These findings highlight that adequate anticoagulation, not just its use, is critical to minimize recurrence risk. To effectively prevent strokes in high-risk AF patients, future strategies must focus on standardized protocols, tailored monitoring, and individualized dosing regimens.

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.

NR4A3 prevents diabetes induced atrial cardiomyopathy by maintaining mitochondrial energy metabolism and reducing oxidative stress

BACKGROUND

Atrial cardiomyopathy (ACM) is responsible for atrial fibrillation (AF) and thromboembolic events. Diabetes mellitus (DM) is an important risk factor for ACM. However, the potential mechanism between ACM and DM remains elusive.

METHODS

Atrial tissue samples were obtained from patients diagnosed with AF or sinus rhythm (SR) to assess alterations in NR4A3 expression, and then two distinct animal models were generated by subjecting Nr4a3-/- mice and WT mice to a high-fat diet (HFD) and Streptozotocin (STZ), while db/db mice were administered AAV9-Nr4a3 or AAV9-ctrl. Subsequently, in vivo and in vitro experiments were conducted to assess the impact of NR4A3 on diabetes-induced atrial remodeling through electrophysiological, biological, and histological analyses. RNA sequencing (RNA-seq) and metabolomics analysis were employed to unravel the downstream mechanisms.

FINDINGS

The expression of NR4A3 was significantly decreased in atrial tissues of both AF patients and diabetic mice compared to their respective control groups. NR4A3 deficiency exacerbated atrial hypertrophy and atrial fibrosis, and increased susceptibility to pacing-induced AF. Conversely, overexpression of NR4A3 alleviated atrial structural remodeling and reduced AF induction rate. Mechanistically, we confirmed that NR4A3 improves mitochondrial energy metabolism and reduces oxidative stress injury by preserving the transcriptional expression of Sdha, thereby exerting a protective influence on atrial remodeling induced by diabetes.

INTERPRETATION

Our data confirm that NR4A3 plays a protective role in atrial remodeling caused by diabetes, so it may be a new target for treating ACM.

FUNDING

This study was supported by the major research program of National Natural Science Foundation of China (NSFC) No: 82370316 (to Q-S. W.), No. 81974041 (to Y-P. W.), and No. 82270447 (to Y-P. W.) and Fundation of Shanghai Hospital Development Center (No. SHDC2022CRD044 to Q-S. W.).

Association between atrial cardiopathy and stroke severity in acute ischemic stroke

In this hospital-based cross-sectional analytic study, we retrospectively reviewed clinical data of patients with acute ischemic stroke (AIS) between January 2017 and April 2023. Atrial cardiopathy was defined as any presence of the following: left atrial diameter ≥ 52 mm (males) or ≥ 47 mm (females), elevated P-wave terminal force in V1 > 5000 μV ms, or serum N terminal pro B type natriuretic peptide > 250 pg/ml. Initial stroke severity was defined by the National Institutes of Health Stroke Scale (NIHSS; moderate-to-severe, ≥ 5; and severe, ≥ 15). Univariate and multivariate binary logistic regression analyses were performed to assess the association between atrial cardiopathy and stroke severity. Among 662 AIS patients (mean age 70 years [interquartile range 61-78], 31.3% women), 303 (45.8%) had atrial cardiopathy. Multivariable logistic regression analysis showed that the presence of atrial cardiopathy was significantly associated with a higher odd of moderate-to-severe stroke (adjusted odds ratio [OR] 2.16, 95% confidence interval [CI] 1.46-3.20, p < 0.001) and severe stroke (adjusted OR 4.89, 95%CI 2.45-9.76, p < 0.001). This association remained significant in a sensitivity analysis excluding those with atrial fibrillation or coronary artery disease. Findings of the current study revealed that the association of atrial cardiopathy was with initial stroke severity independent of atrial fibrillation and was even confirmed in patients without atrial fibrillation; future studies to explore improved stroke prevention strategies for patients with atrial cardiopathy are needed.

Impact of left ventricular diastolic function and direct oral anticoagulant use for predicting embolic events in patients with heart failure and atrial fibrillation

Background

Patients with atrial fibrillation (AF) and heart failure (HF) have high stroke risk owing to left atrial dysfunction. However, anticoagulation is a concern in patients with high bleeding risk. We aimed to identify independent predictors of stroke in HF patients with AF.

Methods

We retrospectively examined 320 patients (mean age 79 ± 12 years, 163 women) hospitalized with acute HF complicated by AF between January 2014 and December 2018. Patients were followed from admission until ischemic stroke or systemic embolism (SSE) onset or death or were censored at the last contact date or September 2023.

Results

SSE occurred in 40 patients (median follow-up of 528 days). Multivariate Cox regression analysis identified age (hazard ratio [HR] 1.04, 95% confidence interval [CI] 1.00-1.07, p = .034), direct oral anticoagulant (DOAC) use (HR 0.26, 95% CI 0.11-0.60, p = .002), and early diastolic peak flow velocity to early diastolic peak annular velocity (E/e'; HR 1.05, 95% CI 1.02-1.08, p < .001) to be independent predictors of SSE, whereas left atrial reservoir strain was not. After determining an appropriate E/e' cutoff by receiver-operating characteristic curve analysis and adjusting the multivariate Cox model, E/e' ≥17.5 (HR 3.30, 95% CI 1.56-6.83, p = .001) independently predicted SSE. The results were consistent with no interaction in the subanalysis except for gender.

Conclusion

Elderly patients not on DOACs with elevated E/e' may be at higher risk of stroke, suggesting that DOACs should be the first choice for patients with elevated E/e' and aggressive additional prophylaxis and careful follow-up are needed.

Atrial myopathy

This paper delves into the progressive concept of atrial myopathy, shedding light on its development and its impact on atrial characteristics. It extensively explores the intricate connections between atrial myopathy, atrial fibrillation (AF), and strokes. Researchers have sought additional contributors to AF-related strokes due to the absence of a clear timing correlation between paroxysmal AF episodes and strokes in patients with cardiac implantable electronic devices. Through various animal models and human investigations, a close interrelation among aging, inflammation, oxidative stress, and stretching mechanisms has been identified. These mechanisms contribute to fibrosis, alterations in electrical properties, autonomic remodeling, and a heightened pro-thrombotic state. These interconnected factors establish a detrimental cycle, exacerbating atrial myopathy and elevating the risk of sustained AF and strokes. By emphasizing the significance of atrial myopathy and the risk of strokes that are distinct from AF, the paper also discusses methods for identifying patients with atrial myopathy. Moreover, it proposes an approach to incorporate the concept of atrial myopathy into clinical practice to guide anticoagulation decisions in individuals with AF.

The relationship between atrial cardiopathy biomarkers and prognosis of patients with acute ischemic stroke after endovascular treatment

Thromboembolism is a possible consequence of underlying atrial cardiopathy, which can occur even before the onset of atrial fibrillation. Our objective was to examine the association between biomarkers of atrial cardiopathy and outcomes of acute ischemic stroke (AIS) following endovascular treatment (EVT). We conducted a retrospective study that collected data from patients with AIS who underwent EVT and compared the outcomes between those with and without atrial cardiopathy. Neurological function was assessed using the modified Rankin Scale (mRS), with an mRS score >2 indicating poor function at day 90. Additionally, we evaluated secondary consequences, including symptomatic intracerebral hemorrhage (sICH), early neurological deterioration (END), and malignant cerebral edema (MCE). Our study included 87 patients (77.6 ​% male; mean age 60.93 ​± ​12.47 years). Among these patients, 29 (33.3 ​%) had atrial cardiopathy, while the remaining 58 (66.7 ​%) did not. In the atrial cardiopathy group, 12 patients (41.4 ​%) had poor functional outcomes (mRS>2), compared to 19 (32.8 ​%) in the non-atrial cardiopathy group. We observed sICH in 22 (25.3 ​%) patients, END in 14 (16.1 ​%) patients, MCE in 11 (12.6 ​%) patients, and two (2.3 ​%) patients who died in the hospital. We found that patients with PTFV1>5000 ​μV/ms (OR: 8.39, 95 ​% CI: 1.43-105.95, P ​= ​0.02) and NT-proBNP>250 ​pg/mL (OR: 5.09, 95 ​% CI: 1.20-27.63, P ​= ​0.03) had significantly higher risk of END. After adjusting for covariates in the Firth logistic regression, we further found that atrial cardiopathy was significantly associated with END, as revealed by both univariate (OR: 6.31, 95 ​% CI: 1.42-59.87, P ​= ​0.01) and multivariable firth regression models (Modle 1, OR: 7.10, 95 ​% CI: 1.57-67.38, P ​< ​0.01; Modle 2, OR: 7.82, 95 ​% CI: 1.69, 76.36, P ​< ​0.01; Modle 3, OR: 8.59, 95 ​% CI: 1.72-91.70, P ​< ​0.01). Moreover, we observed that atrial cardiopathy was associated with an increased risk of END in AIS patients with large artery atherosclerosis (LAA) receiving EVT. Therefore, clinicians should consider atrial cardiopathy as a possible underlying cause of AIS in their patients. Further investigation is warranted to elucidate the relationship between atrial cardiopathy and AIS's occurrence, progression, and prognosis.

Characteristics and Mechanism of Acute Ischemic Stroke in NAVF Patients With Prior Oral Anticoagulant Therapy

OBJECTIVES

We aimed to analyze the characteristics and mechanisms of acute ischemic stroke (AIS) in patients with nonvalvular atrial fibrillation (NVAF) who received prior anticoagulant therapy.

METHODS

We retrospectively analyzed the data of patients with NVAF and AIS between January 2016 and December 2021. Patients were divided into non-anticoagulant, adequate anticoagulant, and insufficient anticoagulant groups according to their prior anticoagulant status. Patients with prior anticoagulant therapy were further divided into warfarin and direct oral anticoagulant groups.

RESULTS

A total of 749 patients (661 without anticoagulants, 33 with adequate anticoagulants, and 55 with insufficient anticoagulants) were included. Patients with adequate anticoagulant had a milder National Institute of Health Stroke Scale at presentation ( P =0.001) and discharge ( P =0.003), a higher proportion of Modified Rankin Scale (mRS) ≤2 at discharge ( P =0.011), and lower rates of massive infarction ( P =0.008) than patients without anticoagulant. Compared with the non-anticoagulant group, the proportion of intravenous thrombolysis was significantly lower in the adequate anticoagulant ( P <0.001) and insufficient anticoagulant ( P =0.009) groups. Patients in the adequate anticoagulant group had higher rates of responsible cerebral atherosclerotic stenosis ( P =0.001 and 0.006, respectively) and competing large artery atherosclerotic mechanisms ( P =0.006 and 0.009, respectively) than those in the other 2 groups. Compared with warfarin, direct oral anticoagulant was associated with higher rates of Modified Rankin Scale ≤2 at discharge ( P =0.003).

CONCLUSIONS

Adequate anticoagulant therapy may be associated with milder stroke severity and better outcomes at discharge in patients with NVAF. Competing large artery atherosclerotic mechanisms may be associated with anticoagulant failure in patients with NAVF with prior adequate anticoagulant therapy.

Atrial Fibrillation and Diabetes Mellitus: Dangerous Liaisons or Innocent Bystanders?

Atrial fibrillation (AF) is the most common arrhythmia in adults and diabetes mellitus (DM) is a major risk factor for cardiovascular diseases. However, the relationship between both pathologies has not been fully documented and new evidence supports the existence of direct and independent links. In the myocardium, a combination of structural, electrical, and autonomic remodeling may lead to AF. Importantly, patients with AF and DM showed more dramatic alterations than those with AF or DM alone, particularly in mitochondrial respiration and atrial remodeling, which alters conductivity, thrombogenesis, and contractile function. In AF and DM, elevations of cytosolic Ca²⁺ and accumulation of extra cellular matrix (ECM) proteins at the interstitium can promote delayed afterdepolarizations. The DM-associated low-grade inflammation and deposition/infiltration of epicardial adipose tissue (EAT) enforce abnormalities in Ca²⁺ handling and in excitation-contraction coupling, leading to atrial myopathy. This atrial enlargement and the reduction in passive emptying volume and fraction can be key for AF maintenance and re-entry. Moreover, the stored EAT can prolong action of potential durations and progression from paroxysmal to persistent AF. In this way, DM may increase the risk of thrombogenesis as a consequence of increased glycation and oxidation of fibrinogen and plasminogen, impairing plasmin conversion and resistance to fibrinolysis. Additionally, the DM-associated autonomic remodeling may also initiate AF and its re-entry. Finally, further evidence of DM influence on AF development and maintenance are based on the anti-arrhythmogenic effects of certain anti-diabetic drugs like SGLT2 inhibitors. Therefore, AF and DM may share molecular alterations related to Ca²⁺ mobility, mitochondrial function and ECM composition that induce atrial remodeling and defects in autonomic stimulation and conductivity. Likely, some specific therapies could work against the associated cardiac damage to AF and/or DM.

Atrial Cardiomyopathy with Impaired Functional Reserve in Patients with Paroxysmal Atrial Fibrillation

BACKGROUND

Impaired atrial functional reserve during exercise may represent an early stage of atrial cardiomyopathy. To test this hypothesis, the authors evaluated left atrial (LA) and left ventricular (LV) function reserve during exercise in patients with paroxysmal atrial fibrillation (PAF).

METHODS

Sixty-one patients with PAF undergoing radiofrequency catheter ablation and 38 healthy control subjects were prospectively enrolled. LV global longitudinal strain and LA reservoir strain (RS) were measured at rest and during supine bicycle exercise. To identify the early stage of atrial cardiomyopathy without LA structural remodeling, patients with PAF were divided into two groups according to LA volume index (LAVI): atrial fibrillation (AF) group 1 (LAVI ≥ 34 mL/m²) and AF group 2 (LAVI < 34 mL/m²).

RESULTS

LV ejection fraction and global longitudinal strain did not differ between patients with AF and control subjects. LAVI and LA RS did not differ between AF group 2 and control subjects. During exercise, LV global longitudinal strain improved in all groups. Increases in LA RS were attenuated in both AF groups, which also exhibited lower LA functional reserve index than the control subjects. Although resting LA RS was similar between AF group 2 and control subjects, LA functional reserve index was significantly lower in AF group 2. LA functional reserve index was associated with risk for AF recurrence (hazard ratio, 0.852; 95% CI, 0.736-0.988).

CONCLUSIONS

Atrial cardiomyopathy can be anticipated by impaired LA functional reserve during exercise in patients with AF, even in those with normal-sized left atria. Atrial cardiomyopathy occurs independently of changes in LV function and is associated with the recurrence of AF in patients with PAF after radiofrequency catheter ablation.

Multimodality imaging assessment of the Biatrial remodeling of the burden of atrial high-rate episodes in patients with cardiac implanted electronic devices

AIMS

The underlying mechanisms of atrial remodeling in cardiac implanted electronic device(CIED)-detected atrial high-rate episodes(AHRE) remains to be elucidated.

METHODS

A cardiac computed tomography and a strain echocardiography were performed to delineate the structural and functional characteristics of both atria. Biatrial volumes, emptying fraction(EF) and peak atrial longitudinal/contractile strain(PALS/PACS) were evaluated. All AHRE were analyzed.

RESULTS

A total of 80 CIED patients with AHRE were categorized by AHRE duration into 3 groups: Group 1: <6 min(n = 42), Group 2: 6 min ∼ 6 h(n = 23), and Group 3: >6 h(n = 15). Left atrial(LA) maximal volume(V_max), atrial precontraction volume(V_apc), minimal volume(V_min), LAEF, and PALS/PACS were all increasingly worsened among the patients in the 3 groups (p value for trend <0.05). Compared to Group 1, Group 2 had decreased LA PALS/PACS. There was no significant difference in LA volume or EF between Group 1 and 2. Group 3 had enlarged biatrial volumes (LAV_max: 57.1(SD 16.0) vs. 45.4(SD 9.2) mL/m², p = 0.002; LAV_min: 42.6(SD 18.2) vs. 28.2(SD 7.2) mL/m², p < 0.001), impaired total LAEF (28.0(SD 13.7) vs. 38.2(SD 7.7)%, p = 0.004) and reduced PALS/PACS compared to Group 1. Atrial remodeling in those with AHRE >6 h had increased LA volumes, impaired LAEF and reduced PALS/PACS compared to those with AHRE <6 h.

CONCLUSION

Functional remodeling of the atria manifested after AHRE >6 min. Increased biatrial volumes and decreased LA reservoir and pump function occurred when AHRE were > 6 h. These LA structural and functional may be considered surrogate imaging markers for stroke risk assessment in patients with CHA₂DS₂-VASc ≥2 and AHRE.

Early atrial remodeling predicts the risk of cardiovascular events in patients with metabolic syndrome: a retrospective cohort study

Background

This study aims to assess the prevalence of atrial cardiomyopathy (ACM) in patients with new-onset metabolic syndrome (MetS) and investigate whether ACM could be a predictor of hospital admission for cardiovascular (CV) events.

Methods

Patients with MetS who were free of clinically proven atrial fibrillation and other CV diseases (CVDs) at baseline were included in the present study. The prevalence of ACM was compared between MetS patients with and without left ventricular hypertrophy (LVH). The time to first hospital admission for a CV event between subgroups was assessed using the Cox proportional hazard model.

Results

A total of 15,528 MetS patients were included in the final analysis. Overall, LVH patients accounted for 25.6% of all newly diagnosed MetS patients. ACM occurred in 52.9% of the cohort and involved 74.8% of LVH patients. Interestingly, a significant percentage of ACM patients (45.4%) experienced MetS without LVH. After 33.2 ± 20.6 months of follow-up, 7,468 (48.1%) patients had a history of readmission due to CV events. Multivariable Cox regression analysis revealed that ACM was associated with an increased risk of admission for CVDs in the MetS patients with LVH [hazard ratio (HR), 1.29; 95% confidence interval (CI), 1.142-1.458; P < 0.001]. Likewise, ACM was found to be independently associated with hospital readmission due to CVD-related events in MetS patients without LVH (HR, 1.175; 95% CI, 1.105-1.250; P < 0.001).

Conclusion

ACM is a marker of early myocardial remodeling and predicts hospitalization for CV events in patients with MetS.

Atrial fibrillation in cryptogenic stroke and TIA patients in the nordic atrial fibrillation and stroke The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Main results

Introduction:

Secondary stroke prevention depends on proper identification of the underlying etiology and initiation of optimal treatment after the index event. The aim of the NOR-FIB study was to detect and quantify underlying atrial fibrillation (AF) in patients with cryptogenic stroke (CS) or transient ischaemic attack (TIA) using insertable cardiac monitor (ICM), to optimise secondary prevention, and to test the feasibility of ICM usage for stroke physicians.

Patients and methods:

Prospective observational international multicenter real-life study of CS and TIA patients monitored for 12 months with ICM (Reveal LINQ) for AF detection.

Results:

ICM insertion was performed in 91.5% by stroke physicians, within median 9 days after index event. Paroxysmal AF was diagnosed in 74 out of 259 patients (28.6%), detected early after ICM insertion (mean 48 ± 52 days) in 86.5% of patients. AF patients were older (72.6 vs 62.2; p < 0.001), had higher pre-stroke CHA₂DS₂-VASc score (median 3 vs 2; p < 0.001) and admission NIHSS (median 2 vs 1; p = 0.001); and more often hypertension ( p = 0.045) and dyslipidaemia ( p = 0.005) than non-AF patients. The arrhythmia was recurrent in 91.9% and asymptomatic in 93.2%. At 12-month follow-up anticoagulants usage was 97.3%.

Discussion and conclusions:

ICM was an effective tool for diagnosing underlying AF, capturing AF in 29% of the CS and TIA patients. AF was asymptomatic in most cases and would mainly have gone undiagnosed without ICM. The insertion and use of ICM was feasible for stroke physicians in stroke units.

Association between comorbidities and left and right atrial dysfunction in patients with paroxysmal atrial fibrillation: Analysis of AF-RISK

BACKGROUND

To identify the association between comorbidities and left atrial (LA) and right atrial (RA) function in patients with paroxysmal atrial fibrillation (AF).

METHODS

This is a cross-sectional study. Speckle-tracking echocardiography was performed in 344 patients with paroxysmal AF at baseline, and available in 298 patients after 1-year follow-up. The number of comorbidities (hypertension, diabetes mellitus, coronary artery disease, body mass index > 25 kg/m², age > 65 years, moderate to severe mitral valve regurgitation and kidney dysfunction (estimated glomerular filtration rate < 60 ml/min/1.73 m²)) was determined and the association with atrial strain was tested.

RESULTS

Mean age of the patients was 58 (SD 12) years and 137 patients were women (40%). Patients with a higher number of comorbidities had larger LA volumes (p for trend <0.001), and had a decrease in all strain phases from the LA and RA, except for the RA contraction phase (p for trend 0.47). A higher number of comorbidities was associated with LA reservoir and conduit strain decrease independently of LA volume (p < 0.001, p < 0.001 respectively). Patients with 1-2 comorbidities, but not patients with 3 or more comorbidities, showed a further progression of impaired LA and RA function in almost all atrial strain phases at 14 [13-17] months follow-up.

CONCLUSIONS

In patients with paroxysmal AF, individual and combined comorbidities are related to lower LA and RA strain. In patients with few comorbidities, impairment in atrial function progresses during one year of follow-up. Whether comorbidity management prevents or reverses decrease in atrial function warrants further study.

Multimodal Approach for the Prediction of Atrial Fibrillation Detected After Stroke: SAFAS Study

Background

Intensive screening for atrial fibrillation (AF) has led to a better recognition of this cause in stroke patients. However, it is currently debated whether AF Detected After Stroke (AFDAS) has the same pathophysiology and embolic risk as prior-to-stroke AF. We thus aimed to systematically approach AFDAS using a multimodal approach combining clinical, imaging, biological and electrocardiographic markers.

Methods

Patients without previously known AF admitted to the Dijon University Hospital (France) stroke unit for acute ischemic stroke were prospectively enrolled. The primary endpoint was the presence of AFDAS at 6 months, diagnosed through admission ECG, continuous electrocardiographic monitoring, long-term external Holter during the hospital stay, or implantable cardiac monitor if clinically indicated after discharge.

Results

Of the 240 included patients, 77 (32%) developed AFDAS. Compared with sinus rhythm patients, those developing AFDAS were older, more often women and less often active smokers. AFDAS patients had higher blood levels of NT-proBNP, osteoprotegerin, galectin-3, GDF-15 and ST2, as well as increased left atrial indexed volume and lower left ventricular ejection fraction. After multivariable analysis, galectin-3 ≧ 9 ng/ml [OR 3.10; 95% CI (1.03–9.254), p = 0.042], NT-proBNP ≧ 290 pg/ml [OR 3.950; 95% CI (1.754–8.892, p = 0.001], OPG ≥ 887 pg/ml [OR 2.338; 95% CI (1.015–5.620), p = 0.046) and LAVI ≥ 33.5 ml/m2 [OR 2.982; 95% CI (1.342–6.625), p = 0.007] were independently associated with AFDAS.

Conclusion

A multimodal approach combining imaging, electrocardiography and original biological markers resulted in good predictive models for AFDAS. These results also suggest that AFDAS is probably related to an underlying atrial cardiopathy.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT03570060].

The Relationship Between Atrial Cardiopathy Biomarkers and Prognosis of Patients With Embolic Stroke of Undetermined Source

Objective

To compare the proportion of atrial cardiopathy in patients with embolic stroke of undetermined source (ESUS) and other non-cardiac strokes, and to evaluate the prognostic value of atrial cardiopathy biomarkers in patients with ESUS.

Methods

This retrospective study enrolled patients with ischemic stroke from January 2018 to April 2020 in a single stroke center, and compared the proportion of atrial cardiopathy in (1) ESUS group, (2) large artery atherosclerosis (LAA) group, and (3) small-vessel occlusion (SVO) group. Then, it compared the baseline characteristics between ESUS patients with atrial cardiopathy and cardioembolism (CE) group. In addition, the relationship was compared between the biomarkers of atrial cardiopathy and prognosis in patients with ESUS.

Results

In total, 316 patients with ischemic stroke were included that included 105 (33.23%) ESUS, 84 (26.58%) LAA, 73 (23.10%) SVO, and 54 (17.09%) CE. Among these patients, patients with ESUS were younger, and had lower triglyceride, lower low-density lipoprotein than non-ESUS group. The proportion of atrial cardiopathy in ESUS group was higher than LAA group or SVO group (42.86 vs. 17.86 vs. 8.22%, p < 0.001). Compared with non-atrial cardiopathy group, patients with atrial cardiopathy were older, had lower EF value, larger left ventricular diameter, and longer PR interval. Among 105 patients with ESUS, 11 (10.78%) cases died, 32 (31.37%) cases had poor functional outcome (mRS >2). In the multivariable model, the risk factor associated with the death risk of patients with ESUS was N-terminal pro-B-type natriuretic peptide (NT-proBNP) >250 pg/ml [p = 0.025, hazard ratio (HR) = 4.626, 95% CI: 1.212–17.652] after a 1-year follow-up.

Conclusions

Atrial cardiopathy is more common in patients with ESUS, and the characteristics of ESUS patients with atrial cardiopathy are similar to those in patients with CE. NT-proBNP >250 pg/ml is related to the risk of death in patients with ESUS.

Left Atrial Appendage Thrombus in Patients with Nonvalvular Atrial Fibrillation before Catheter Ablation and Cardioversion: Risk Factors beyond the CHA2DS2-VASc Score

Left atrial appendage thrombus (LAAT) is a surrogate of thromboembolic events in patients with nonvalvular atrial fibrillation (NVAF). We aimed to investigate the risk factors for LAAT formation before catheter ablation and cardioversion beside the CHA2DS2-VASc score. In this case-control study, patients with NVAF who underwent transesophageal echocardiography (TEE) were included. Demographic data, laboratory results, and echocardiographic measurements were retrospectively collected. Logistic regression analysis was performed to determine risk factors predicting LAAT. Of the 543 included patients, LAAT was identified in 50 patients (9.2%). Multivariable logistic regression analysis for the entire cohort showed that NT-proBNP (per 500 ng/L increase, OR (95% CI): 1.09 (1.00–1.19), p = 0.038) and LDL-C (per 1 mmol/L increase, OR (95% CI): 1.70 (1.05–2.77), p = 0.032) were independently correlated with the presence of LAAT after the adjustment for CHA2DS2-VASc score and anticoagulant therapy. The subgroup analysis of patients without anticoagulant therapy also yielded similar results. Regarding patients with CHA2DS2-VASc scores ≤ 1, a higher level of LDL-C (per 1 mmol/L increase, OR (95% CI): 6.31 (2.38–16.74), p < 0.001) independently correlated with the presence of LAAT. The present study suggests that beyond CHA2DS2-VASc score, raised NT-proBNP and LDL-C are additional predictors for LAAT in NVAF patients.

Temporal Association Between Episodes of Atrial Fibrillation and Risk of Ischemic Stroke

Importance

Understanding the temporal association between atrial fibrillation (AF) and ischemic stroke informs our understanding of the AF-stroke mechanism and treatment of paroxysmal AF.

Objective

To define the temporal association between episodes of AF and stroke in patients with cardiac implantable electronic devices (CIEDs).

Design, Setting, and Participants

In this case-crossover study, data from a large national electronic health record database were linked with a single-vendor database of heart rhythm records of patients with CIEDs capable of continuous heart rhythm monitoring. Patients with CIEDs who sustained an ischemic stroke who also had 120 days of continuous remote rhythm monitoring prestroke were included. Data were collected from January 2007 to March 2017, and data were analyzed from November 2019 to June 2020.

Exposure

AF for 5.5 hours or more on any given day during days 1 to 30 vs days 91 to 120 prestroke.

Main Outcomes and Measures

Odds ratio for stroke comparing AF during days 1 to 30 vs 91 to 120 prestroke. This analysis was planned prior to the study.

Results

From 466 635 patients included in both the Optum electronic health record and CareLink databases, 891 patients with CIEDs and ischemic stroke with continuous monitoring in the 120 days prestroke were identified. Of 891 included patients, 575 (64.5%) were male, and the median (interquartile range) age was 76 (67-82) years. The vast majority of patients with stroke had either no AF meeting the threshold duration of 5.5 hours or more in both the case and control periods (682 of 891 [76.5%]) or AF of 5.5 hours or more in both periods (143 of 891 [16.0%]). For those not meeting the 5.5-hour AF threshold in either period, there was no or very little AF throughout the 120 days prestroke. A total of 66 patients had informative, discordant arrhythmic states, with 52 having AF of 5.5 hours or more in the case period vs 14 in the control period (odds ratio [OR], 3.71; 95% CI, 2.06-6.70). Stroke risk was increased most in days 1 to 5 following an AF episode (OR, 5.00; 95% CI, 2.62-9.55). AF greater than 23 hours on a given day was associated with the clearest increase in stroke risk (OR, 5.00; 95% CI, 2.08-12.01).

Conclusions and Relevance

In this large cohort of patients with CIEDs and continuous rhythm monitoring prior to ischemic stroke, excess stroke risk above baseline was highest within 5 days of an episode of AF of 5.5 hours or more in duration and diminished rapidly thereafter. Our findings are consistent with the traditional view that AF is directly and transiently associated with ischemic stroke. These results provide support for trials of time-delimited anticoagulation for patients with infrequent multihour episodes of AF and rigorous, continuous rhythm monitoring.

Transesophageal Echocardiography in Ischemic Stroke With Atrial Fibrillation

Background

To clarify differences in clinical significance of intracardiac thrombi in nonvalvular atrial fibrillation‐associated stroke as identified by transesophageal echocardiography (TEE) and transthoracic echocardiography (TTE).

Methods and Results

Using patient data on nonvalvular atrial fibrillation‐associated ischemic stroke between 2011 and 2014 from 15 South Korean stroke centers (n=4841) and 18 Japanese centers (n=1192), implementation rates of TEE/TTE, and detection rates of intracardiac thrombi at each center were correlated. The primary outcome was recurrent ischemic stroke at 1 year after the onset. A total of 5648 patients (median age, 75 years; 2650 women) were analyzed. Intracardiac thrombi were detected in 75 patients (1.3%) overall. Thrombi were detected in 7.8% of patients with TEE (either TEE alone or TEE+TTE: n=679) and in 0.6% of those with TTE alone (n=3572). Thrombus detection rates varied between 0% and 14.3% among centers. As TEE implementation rates at each center increased from 0% to 56.7%, thrombus detection rates increased linearly (detection rate [%]=0.11×TEE rate [%]+1.09 [linear regression], P<0.01). TTE implementation rates (32.3%–100%) were not associated with thrombus detection rates (P=0.53). Intracardiac thrombi were associated with risk of recurrent ischemic stroke overall (adjusted hazard ratio [aHR] 2.35, 95% CI, 1.07–5.16). Thrombus‐associated ischemic stroke risk was high in patients with TEE (aHR, 3.13; 95% CI, 1.17–8.35), but not in those with TTE alone (aHR, 0.89; 95% CI, 0.12–6.51).

Conclusions

Our data suggest clinical relevance of TEE for accurate detection and risk stratification of intracardiac thrombi in nonvalvular atrial fibrillation‐associated stroke.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01581502.

Infarct volume and outcome of cerebral ischaemia, a systematic review and meta-analysis

BACKGROUND

Multiple studies have evaluated the accuracy of infarct volume (IV) as a predictor of outcome in patients with ischaemic stroke; however, no study has systematically reviewed the results of these studies.

AIM

This systematic review and meta-analysis aim to sum up the results of the studies evaluating IV as the prognostic criteria for patients with cerebral ischaemia.

METHODS

Human studies that reported the infarction volume and any prognostic outcome in patients with ischaemic stroke were collected from PubMed, Scopus, Embase and Cochrane library databases. Newcastle-Ottawa Quality Assessment Checklist was applied to evaluate the quality of the included articles. 90-day modified Rankin Scale (mRS) score was used as a meta-analysis outcome. The area under the curve, sensitivity and specificity among included studies was evaluated. The heterogeneity of the studies was assessed by Cochran test Egger and Begg test was used for assessing publication bias.

RESULTS

Among the included studies, nine studies assessed the association between IV and outcome (90-day mRS score). The results of the meta-analysis revealed a significant association between IV with the unfavourable functional outcome (mRS score of 3-6) (OR = 0.80; 95% CI: 0.74-0.86 per 10 mL, P < .001; I²  = 98.1%, P < .001). The infarction volume cut of point between 20 and 50 mL showed the best sensitivity and specificity for the prediction of poor clinical outcomes in patients with ischaemic stroke.

CONCLUSION

The results of the meta-analysis revealed a significant association between IV and unfavourable functional outcomes in patients with ischaemic stroke.

Relationship Between Change in Serum Uric Acid and Ischemic Stroke in Chinese Hypertensive Patients

Background: Limited studies focused on the association between serum uric acid (SUA) change with ischemic stroke, and their results remain controversial. The present study aimed to investigate the relationship between change in SUA with ischemic stroke among hypertensive patients.

Method: This was a retrospective cohort study. We recruited adult hypertensive patients who had two consecutive measurements of SUA levels from 2013 to 2014 and reported no history of stroke. Change in SUA was assessed as SUA concentration measured in 2014 minus SUA concentration in 2013. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). The Kaplan–Meier analysis and log-rank test were performed to quantify the difference in cumulative event rate. Additionally, subgroup analysis and interaction tests were conducted to investigate heterogeneity.

Results: A total of 4,628 hypertensive patients were included, and 93 cases of ischemic stroke occurred during the mean follow-up time of 3.14 years. Participants were categorized into three groups according to their SUA change tertiles [low (SUA decrease substantially): <-32.6 μmol/L; middle (SUA stable): ≥-32.6 μmol/L, <40.2 μmol/L; high (SUA increase substantially): ≥40.2 μmol/L]. In the fully adjusted model, setting the SUA stable group as reference, participants in the SUA increase substantially group had a significantly elevated risk of ischemic stroke [HR (95% CI), 1.76 (1.01, 3.06), P = 0.0451], but for the SUA decrease substantially group, the hazard effect was insignificant [HR (95% CI), 1.31 (0.75, 2.28), P = 0.3353]. Age played an interactive role in the relationship between SUA change and ischemic stroke. Younger participants (age < 65 years) tended to have a higher risk of ischemic stroke when SUA increase substantially.

Conclusion: SUA increase substantially was significantly correlated with an elevated risk of ischemic stroke among patients with hypertension.

Prediction of recurrent stroke among ischemic stroke patients with atrial fibrillation: Development and validation of a risk score model

BACKGROUND

There is currently no validated risk prediction model for recurrent events among patients with acute ischemic stroke (AIS) and atrial fibrillation (AF). Considering that the application of conventional risk scores has contextual limitations, new strategies are needed to develop such a model. Here, we set out to develop and validate a comprehensive risk prediction model for stroke recurrence in AIS patients with AF.

METHODS

AIS patients with AF were collected from multicenter registries in South Korea and Japan. A developmental dataset was constructed with 5648 registered cases from both countries for the period 2011‒2014. An external validation dataset was also created, consisting of Korean AIS subjects with AF registered between 2015 and 2018. Event outcomes were collected during 1 year after the index stroke. A multivariable prediction model was developed using the Fine-Gray subdistribution hazard model with non-stroke mortality as a competing risk. The model incorporated 21 clinical variables and was further validated, calibrated, and revised using the external validation dataset.

RESULTS

The developmental dataset consisted of 4483 Korean and 1165 Japanese patients (mean age, 74.3 ± 10.2 years; male 53%); 338 patients (6%) had recurrent stroke and 903 (16%) died. The clinical profiles of the external validation set (n = 3668) were comparable to those of the developmental dataset. The c-statistics of the final model was 0.68 (95% confidence interval, 0.66 ‒0.71). The developed prediction model did not show better discriminative ability for predicting stroke recurrence than the conventional risk prediction tools (CHADS2, CHA2DS2-VASc, and ATRIA).

CONCLUSIONS

Neither conventional risk stratification tools nor our newly developed comprehensive prediction model using available clinical factors seemed to be suitable for identifying patients at high risk of recurrent ischemic stroke among AIS patients with AF in this modern direct oral anticoagulant era. Detailed individual information, including imaging, may be warranted to build a more robust and precise risk prediction model for stroke survivors with AF.

The CHA2DS2-VASc Score for Risk Stratification of Stroke in Heart Failure With-vs-Without Atrial Fibrillation

A recent study suggested that the CHA₂DS_2-VASc score can risk stratify heart failure (HF) patients without atrial fibrillation (AF) for stroke. We performed a retrospective analysis using the national Veteran Affairs database to externally validate the findings. Crude incidence rates of end points were calculated. A Cox proportional model was used to study the association between the CHA₂DS₂-VASc score and outcomes. In HF patients with AF (n = 17,481) and without AF (n = 36,935), the 1 year incidence rate for ischemic stroke, thromboembolism, thromboembolism (without MI), and death were 2.7 and 2.0%; 10.3 and 7.9%; 4.1 and 3.1%; and 19.2 and 26.0%, respectively, with higher rates with increasing CHA₂DS₂-VASc scores both with and without AF. CHA₂DS₂-VASc score predicted strokes in HF patients without AF (1-year C-statistic 0.62, 95% CI 0.60-0.64; NPV 85.4%, 95% CI 83.4-87.4%) with similar predictive ability to those with AF (C-statistic 0.59, 95% CI 0.56-0.62; NPV 86.4%, 95% CI 82.6-90.2%). Among patients with HF, there was an increased risk of stroke, thromboembolism, and death with increasing CHA₂DS₂-VASc scores regardless of AF status. Our findings support the use of the CHA₂DS₂-VASc score as a prognostic tool in HF.

Atrial fibrillation is associated with increased risk of lethal ventricular arrhythmias

Atrial fibrillation (AF) is associated with various major adverse cardiac events such as ischemic stroke, heart failure, and increased overall mortality. However, its association with lethal ventricular arrhythmias such as ventricular tachycardia (VT), ventricular flutter (VFL), and ventricular fibrillation (VF) is controversial. We conducted this study to determine whether AF can increase the risk of VT, VFL, and VF. We utilized the Korean National Health Insurance Service database for this nationwide population-based study. This study enrolled people who underwent a nationwide health screen in 2009 for whom clinical follow-up data were available until December 2018. Primary outcome endpoint was the occurrence of VT, VFL, or VF in people who were and were not diagnosed with new-onset AF in 2009. We analyzed a total of 9,751,705 people. In 2009, 12,689 people were diagnosed with new-onset AF (AF group). The incidence (events per 1000 person-years of follow-up) of VT, VFL, and VF was 2.472 and 0.282 in the AF and non-AF groups, respectively. After adjustment for covariates, new-onset AF was associated with 4.6-fold increased risk (p < 0.001) of VT, VFL, and VF over 10 years of follow-up. The risk of VT, VFL, and VF was even higher if identification of AF was based on intensified criteria (≥ 2 outpatient records or ≥ 1 inpatient record; hazard ratio = 5.221; p < 0.001). In conclusion, the incidence of VT, VFL, and VF was significantly increased in people with new-onset AF. The potential risk of suffering lethal ventricular arrhythmia in people with AF should be considered in clinical practice.

Electrophysiological ventricular substrate of stroke: a prospective cohort study in the Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVES

The goal of the study was to determine an association of cardiac ventricular substrate with thrombotic stroke (TS), cardioembolic stroke (ES) and intracerebral haemorrhage (ICH).

DESIGN

Prospective cohort study.

SETTING

The Atherosclerosis Risk in Communities (ARIC) study in 1987-1989 enrolled adults (45-64 years), selected as a probability sample from four US communities (Minneapolis, Minnesota; Washington, Maryland; Forsyth, North Carolina; Jackson, Mississippi). Visit 2 was in 1990-1992, visit 3 in 1993-1995, visit 4 in 1996-1998 and visit 5 in 2011-2013.

PARTICIPANTS

ARIC participants with analysable ECGs and no history of stroke were included (n=14 479; age 54±6 y; 55% female; 24% black). Ventricular substrate was characterised by cardiac memory, spatial QRS-T angle (QRS-Ta), sum absolute QRST integral (SAIQRST), spatial ventricular gradient magnitude (SVGmag), premature ventricular contractions (PVCs) and tachycardia-dependent intermittent bundle branch block (TD-IBBB) on 12-lead ECG at visits 1-5.

OUTCOME

Adjudicated TS included a first definite or probable thrombotic cerebral infarction, ES-a first definite or probable non-carotid cardioembolic brain infarction. Definite ICH was included if it was the only stroke event.

RESULTS

Over a median 24.5 years follow-up, there were 899 TS, 400 ES and 120 ICH events. Cox proportional hazard risk models were adjusted for demographics, cardiovascular disease, risk factors, atrial fibrillation, atrial substrate and left ventricular hypertrophy. After adjustment, PVCs (HR 1.72; 95% CI 1.02 to 2.92), QRS-Ta (HR 1.15; 95% CI 1.03 to 1.28), SAIQRST (HR 1.20; 95% CI 1.07 to 1.34) and time-updated SVGmag (HR 1.19; 95% CI 1.08 to 1.32) associated with ES. Similarly, PVCs (HR 1.53; 95% CI 1.03 to 2.26), QRS-Ta (HR 1.08; 95% CI 1.01 to 1.16), SAIQRST (HR 1.07; 95% CI 1.01 to 1.14) and time-updated SVGmag (HR 1.11; 95% CI 1.04 to 1.19) associated with TS. TD-IBBB (HR 3.28; 95% CI 1.03 to 10.46) and time-updated SVGmag (HR 1.23; 95% CI 1.03 to 1.47) were associated with ICH.

CONCLUSIONS

PVC burden (reflected by cardiac memory) is associated with ischaemic stroke. Transient cardiac memory (likely through TD-IBBB) precedes ICH.

Prediction of low-voltage areas using modified APPLE score

AIMS

The presence of low-voltage areas (LVAs) in patients with atrial fibrillation (AF) reflects left atrial (LA) electroanatomical substrate, which is essential for individualized AF management. However, echocardiographic anteroposterior LA diameter included into previous LVAs prediction scores does not mirror LA size accurately and impaired left ventricular ejection fraction (LV-EF) is not directly associated with atrial myopathy. Therefore, we aimed to compare a modified (m)APPLE score, which included LA volume (LAV) and LA emptying fraction (LA-EF) with the regular APPLE score for the prediction of LVAs.

METHODS AND RESULTS

In patients undergoing first AF catheter ablation, LVAs were determined peri-interventionally using high-density maps and defined as signal amplitude <0.5 mV. All patients underwent cardiovascular magnetic resonance imaging before intervention. The APPLE (one point for Age ≥ 65 years, Persistent AF, imPaired eGFR ≤ 60 mL/min/1.73 m2, LA diameter ≥ 43 mm, and LVEF < 50%) and (m)APPLE (last two variables changed by LAV ≥ 39 mL/m2, and LA-EF < 31%) scores were calculated at baseline. The study population included 219 patients [median age 65 (interquartile range 57-72) years, 41% females, 59% persistent AF, 25% LVAs]. Both scores were significantly associated with LVAs [OR 1.817, 95% CI 1.376-2.399 for APPLE and 2.288, 95% CI 1.650-3.172 for (m)APPLE]. Using receiver operating characteristic curves analysis, the (m)APPLE score [area under the curve (AUC) 0.779, 95% CI 0.702-0.855] showed better LVAs prediction than the APPLE score (AUC 0.704, 95% CI 0.623-0.784), however, without statistically significant difference (P = 0.233).

CONCLUSION

The modified (m)APPLE score demonstrated good prognostic value for LVAs prediction and was comparable with the regular APPLE score.

Impact of the Pattern of Atrial Fibrillation on Stroke Risk and Mortality

Thromboembolism is the most serious complication of AF, and oral anticoagulation is the mainstay therapy. Current guidelines place all AF types together in terms of anticoagulation with the major determinants being associated comorbidities translated into risk marker. Among patients in large clinical trials, those with non-paroxysmal AF appear to be at higher risk of stroke than those with paroxysmal AF. Higher complexity of the AF pattern is also associated with higher risk of mortality. Moreover, continuous monitoring of AF through cardiac implantable devices provided us with the concept of 'AF burden'. Usually, the larger the AF burden, the higher the risk of stroke; however, the relationship is not well characterised with respect to the threshold value above which the risk increases. The picture is more complex than it appears: AF and underlying disorders must act synergically respecting the magnitude of its own characteristics, which are the amount of time a patient stays in AF and the severity of associated comorbidities.

Blood-brain barrier disruption in atrial fibrillation: a potential contributor to the increased risk of dementia and worsening of stroke outcomes?

Atrial fibrillation (AF) has become one of the most significant health problems worldwide, warranting urgent answers to currently pending questions on the effects of AF on brain function. Recent evidence has emerged to show an association between AF and an increased risk of developing dementia and worsening of stroke outcomes. A healthy brain is protected by the blood–brain barrier (BBB), which is formed by the endothelial cells that line cerebral capillaries. These endothelial cells are continuously exposed to shear stress (the frictional force generated by blood flow), which affects endothelial cell structure and function. Flow disturbances as experienced during AF can disrupt the BBB and leave the brain vulnerable to damage. Investigating the plausible mechanisms in detail, linking AF to cerebrovascular damage is difficult in humans, leading to paucity of available clinical data. Here, we discuss the available evidence for BBB disruption during AF due to altered cerebral blood flow, and how this may contribute to an increased risk of dementia and worsening of stroke outcomes.

P-wave indices in Japanese patients with ischemic stroke: Implication of atrial myopathy in subtype of ischemic stroke

BACKGROUND

P-wave indices have been not fully studied in subtypes of ischemic stroke. We compared P-wave indices among embolic stroke, lacunar stroke and the control.

METHODS

P-wave duration, advanced interatrial block (aIAB) defined as P-wave duration ≥120 ms and biphasic (positive negative) morphology in inferior leads, and P-terminal force in lead V1 (PTFV1) were measured at the time of the first episode of cardioembolic stroke in 81 patients with paroxysmal atrial fibrillation (PAF), and in 64 patients with lacunar stroke, and compared with 100 control subjects. The latter two groups had no episode of PAF.

RESULTS

The age of participants was 76 ± 11 years. Age, sex distribution, body mass index and CHADS2 score were comparable among three groups. Maximum P-wave duration, the longest across 12 leads, was significantly prolonged in cardioembolic and lacuna stroke compared to the control; 118 ± 12 ms and 118 ± 11 ms vs. 110 ± 11 ms, respectively (P < 0.0001). P-wave duration ≥120 ms and aIAB were more prevalent in ischemic stroke groups than the control, and associated with a higher Odds ratio for stroke, more so in cardioembolic stroke. However, PTFV1 value and the prevalence of PTFV1 ≥ 4.0 ms·mV were significantly not different among the three groups. Abnormal P-wave duration and aIAB indicating the presence of atrial myopathy were present in cardioembolic and lacuna stroke.

CONCLUSION

Atrial myopathy was present in cardioembolic and lacunar stroke, but it can't be the direct cause of small vessel occlusion in lacunar stroke. Roles of atrial myopathy in each subtype of ischemic stroke should be studied.

Blood flow volume of left atrial appendage measured by magnetic resonance imaging is improved after radiofrequency catheter ablation of atrial fibrillation

INTRODUCTION

Hemodynamics of left atrial appendage (LAA) is an important factor for future risk of ischemic stroke in atrial fibrillation (AF) patients. Velocity encoded cardiac magnetic resonance imaging (VENC-MRI) can evaluate blood flow volume of LAA without any invasive procedures. We aimed to evaluate the association between radiofrequency catheter ablation (RFCA) and LAA hemodynamics measured by MRI.

METHODS AND RESULTS

Consecutive RFCA cases in a single arrhythmia center were retrospectively analyzed. A total of 3120 AF patients who underwent first RFCA were analyzed. Among these patients 360 patients had both pre- and post-RFCA VENC-MRI evaluation. Atrial fibrillation was non-paroxysmal in 174 (48.3%) patients. Mean VENC-MRI (ml/sec) was significantly improved after RFCA with 49.93 ± 32.92 and 72.00 ± 34.82 for pre- and post-RFCA, respectively. Patients with non-paroxysmal AF (∆VENC-MRI = 14.63 ± 40.67 vs. 30.03 ± 35.37; p < .001) and low pre-RFCA VENC-MRI (∆VENC-MRI = 17.19 ± 38.35 vs. 50.35 ± 29.12; p < .001) had significantly higher improvement in VENC-MRI. Those who experienced late recurrence before post-RFCA MRI had significantly less improvement in LAA flow volume (∆VENC-MRI = 15.55 ± 41.41 vs. 26.18 ± 36.77; p = .011). Late recurrence and pre-RFCA VENC-MRI were significantly associated with ∆VENC-MRI after adjusting covariates. Patients who were AF before RFCA but maintained sinus rhythm after RFCA showed greatest improvement in VENC-MRI.

CONCLUSION

Effective rhythm control through RFCA can be associated with significant improvement in LAA hemodynamics. Low pre-RFCA VENC-MRI and absence of late recurrence were associated with greater improvement in LAA hemodynamics.

Premature ventricular contraction is associated with increased risk of atrial fibrillation: a nationwide population-based study

Premature ventricular contraction (PVC) and atrial fibrillation (AF) are common arrhythmias affecting 1–2% of the general population. During PVC, retrograde ventriculo-atrial activation can occur and act like an atrial ectopy. However, the clinical significance of this phenomenon is not fully understood. We aimed to elucidate whether the clinical diagnosis of PVC can increase the risk of new-onset AF. We performed a nationwide population-based analysis using the Korean National Health Insurance Service database. A total of 9,537,713 people without prior history of PVC and AF were identified. Among these people, 4135 developed PVC in 2009, and people with and without PVC were followed until 2018. People who had PVC showed an increased risk of new-onset AF as compared with people without PVC (hazard ratio [HR] = 2.705; 95% confidence interval [CI] = 2.428–3.013; p < 0.001). The risk of ischemic stroke was also significantly increased in people with PVC (HR 1.160; 95% CI 1.048–1.284; p = 0.0041). New-onset AF developed in 72 people (19.3%) among 374 people with PVC who had ischemic stroke during their follow-up. A significant interaction was observed between PVC and age with people < 65 years at greater risk of new-onset AF for having PVC. In this observational analysis, the risk of new-onset AF and ischemic stroke was increased in people with PVC. Additional evaluation to identify AF in people with PVC can be helpful.

New Perspective in Atrial Fibrillation

Despite a large number of publications on this subject, the pathophysiological mechanisms involved in atrial fibrillation (AF) onset and recurrence are uncertain [...].

High rate of cardiac thrombus diagnosed by adding cardiac imaging in acute stroke computed tomography protocol

BACKGROUND

Detection of left atrial appendage thrombus (LAAt) in acute stroke patients can be improved by cardiac computed tomography using prospective electrocardiogram-gated volume acquisition, which was added to the acute stroke computed tomography protocol in our institution in 2018.

AIMS

To evaluate the factors and clinical management associated with LAAt in patients with acute ischemic stroke.

METHODS

We retrospectively included 324 consecutive patients with ischemic stroke from November 2018 to October 2019. Clinical data and post-stroke management were compared in LAAt and no-LAAt patients.

RESULTS

Thirty-five patients (10.8%; 95%CI 7.4-14.2) had LAAt and 289 had no-LAAt. LAAt patients were significantly older (82 ± 12 vs. 74 ± 14 yo for no-LAAt, p = 0.002), predominantly female (71% vs. 45%, p = 0.004), and were more likely to have previous atrial fibrillation (63% vs. 15%, p < 0.001) and previous stroke (32% vs. 14%, p = 0.005). There was no significant difference between groups in stroke localization or severity scales at admission or at hospital discharge. After multivariable analysis, female sex (odds ratio 2.51; 95%CI 1.09-5.77, p = 0.031), previous atrial fibrillation (odds ratio 4.87; 95%CI 2.11-11.22, p < 0.001), and left atrial volume >86 ml (odds ratio 5.33; 95%CI 1.70-16.69, p = 0.004) were independently associated with LAAt. More than a third of LAAt patients (37%) received acute heparin therapy compared to 13% of no-LAAt patients (p < 0.001). Moreover, despite comparable stroke severity at admission, the mortality rate was markedly higher in the LAAt group than in the no-LAAt group (37% vs. 13%, p < 0.001).

CONCLUSIONS

Cardiac computed tomography for left atrial appendage thrombus evaluation in routine acute stroke imaging protocol could be beneficial for decision-making with regard to the initiation of early anticoagulation.

A snapshot of Ischemic stroke risk factors, sub-types, and its epidemiology: Cohort study

The burden of stroke can be substantially studied by establishing the functional consequences of stroke and its predictors on the population, economy and to guide rehabilitation efforts. This study aims to determine the subtypes, risk factors, and epidemiology of stroke in Jordan. Methods: A retrospective cohort study design was carried out to determine the risk factors and subtypes of stroke during 2017-2018. The study sample included 176 ischemic stroke patients of the King Abdullah University Hospital. Data was collected through medical records, which was then statistically analysed through frequencies and percentages. Results: Total 176 cases were identified out of which 101 (57.38%) were males and 75 (42.61%) were females and male to female ratio was 1.9:1. Hypertension was the commonest risk factor identified (50.56%), followed by diabetes mellitus (19.88%), hyperlipidaemia (15.34%), coronary artery disease (6.25%), atrial fibrillation (4.54%), and past history of stroke (1.13%). Risk factors such as hypertension (p = 0.007), diabetes (p = 0.000), coronary artery disease (p = 0.000) were significantly associated with subtypes of ischemic strokes. Conclusion: The study concludes that mean age of men was higher as compared to women in small vessel occlusion. The risk of ischemic stroke in patients with dyslipidaemia, diabetes mellitus, and hypertension was higher in middle-aged and old patients.

Relationship between device-detected burden and duration of atrial fibrillation and risk of ischemic stroke

BACKGROUND

Wider availability of continuous rhythm monitoring has made feasible the incorporation of metrics of atrial fibrillation (AF) burden and duration into the decision to initiate anticoagulation. However, the relationship between thresholds of burden and duration and underlying risk factors at which anticoagulation should be considered remains unclear.

OBJECTIVE

The purpose of this study was to evaluate the relationships of these metrics with each other and the outcome of stroke/transient ischemic attack (TIA).

METHODS

We identified patients with cardiovascular implantable electronic devices (CIEDs) with atrial leads who had at least 1 interrogation in 2016 demonstrating nonpermanent AF and were not receiving oral anticoagulation (OAC). We evaluated the relationship between burden (ie, percentage of time spent in AF), the longest single episode of AF, and risk factors (ie, CHA₂DS₂-VASc score) in predicting risk of stroke/TIA.

RESULTS

The study included 384 patients with mean follow-up of 3.2 ± 0.8 years and incidence of stroke/TIA of 14.8% during follow-up (∼4.6% per year). The burden of AF and the duration of longest episode demonstrated a significant positive correlation to each other but not CHA₂DS₂-VASc score. Importantly, although the CHA₂DS₂-VASc score was predictive of stroke/TIA, neither burden nor duration was associated with stroke/TIA.

CONCLUSION

Among patients with CIED-detected AF not receiving OAC, the amount of AF (measured by either burden or duration) does not seem to significantly impact stroke risk, whereas CHA₂DS₂-VASc score does. These data suggest that among patients with CIED-detected AF, once AF occurs, stroke risk seems to be predominantly driven by underlying risk factors.

Software-based analysis of 1-hour Holter ECG to select for prolonged ECG monitoring after stroke

Objective

Identification of ischemic stroke patients at high risk for paroxysmal atrial fibrillation (pAF) during 72 hours Holter ECG might be useful to individualize the allocation of prolonged ECG monitoring times, currently not routinely applied in clinical practice.

Methods

In a prospective multicenter study, the first analysable hour of raw ECG data from prolonged 72 hours Holter ECG monitoring in 1031 patients with acute ischemic stroke/TIA presenting in sinus rhythm was classified by an automated software (AA) into “no risk of AF” or “risk of AF” and compared to clinical variables to predict AF during 72 hours Holter‐ECG.

Results

pAF was diagnosed in 54 patients (5.2%; mean age: 78 years; female 56%) and was more frequently detected after 72 hours in patients classified by AA as “risk of AF” (n = 21, 17.8%) compared to “no risk of AF” (n = 33, 3.6%). AA‐based risk stratification as “risk of AF” remained in the prediction model for pAF detection during 72 hours Holter ECG (OR3.814, 95% CI 2.024‐7.816, P < 0.001), in addition to age (OR1.052, 95% CI 1.021‐1.084, P = 0.001), NIHSS (OR 1.087, 95% CI 1.023‐1.154, P = 0.007) and prior treatment with thrombolysis (OR2.639, 95% CI 1.313‐5.306, P = 0.006). Similarly, risk stratification by AA significantly increased the area under the receiver operating characteristic curve (AUC) for prediction of pAF detection compared to a purely clinical risk score (AS5F alone: AUC 0.751; 95% CI 0.724‐0.778; AUC for the combination: 0.789, 95% CI 0.763‐0.814; difference between the AUC P = 0.022).

Interpretation

Automated software‐based ECG risk stratification selects patients with high risk of AF during 72 hours Holter ECG and adds predictive value to common clinical risk factors for AF prediction.

Atrial Cardiopathy in the Absence of Atrial Fibrillation Increases Risk of Ischemic Stroke, Incident Atrial Fibrillation, and Mortality and Improves Stroke Risk Prediction

Background Atrial fibrillation (AF) is a major, often undetected, cardiac cause of stroke. Markers of atrial cardiopathy, including left atrial enlargement (LAE) or excessive atrial ectopy (EAE) increase the risk of AF and have shown associations with stroke. We sought to determine whether these markers improve stroke risk prediction beyond traditional vascular risk factors (eg CHA₂DS₂-VASc score). Methods and Results Retrospective longitudinal cohort of 32 454 consecutive community-dwelling adults aged ≥65 years referred for outpatient echocardiogram or Holter in Ontario, Canada (2010-2017). Moderate-severe LAE was defined as men >47 mm and women >43 mm, and EAE was defined as >30 APBs per hour. Cause-specific competing risks Cox proportional hazards used to estimate risk of ischemic stroke (primary), incident AF, and death (secondary). C-statistics, incremental discrimination improvement and net reclassification were used to compare CHA₂DS₂-VASc with LAE and EAE to CHA₂DS₂-VASc alone. Each 10 mm increase in left atrial diameter increased 2- and 5-year adjusted cause-specific stroke hazard almost 2-fold (LAE: 2-year hazard ratio (HR), 1.72; P=0.007; 5-year HR, 1.87; P<0.0001), while EAE showed no significant associations with stroke (2-year HR, 1.00; P=0.99; 5-year HR, 1.08, P=0.70), adjusting for incident AF. Stroke risk estimation improved significantly at 2 (C-statistics=0.68-0.75, P=0.008) and 5 years (C-statistics=0.70-0.76, P=0.003) with LAE and EAE. Conclusions LAE was independently associated with an increased risk of ischemic stroke in the absence of AF and both LAE and EAE improved stroke risk prediction. These findings have implications for stroke risk stratification, AF screening, and stroke prevention before the onset of AF.

Measuring atrial stasis during sinus rhythm in patients with paroxysmal atrial fibrillation using 4 Dimensional flow imaging: 4D flow imaging of atrial stasis

BACKGROUND

Paroxysmal atrial fibrillation (PAF) is associated with cardioembolic risk, however events may occur during sinus rhythm (SR). 4D-flow cardiac magnetic resonance (CMR) imaging allows visualisation of left atrial blood flow, to determine the residence time distribution (RTD), an assessment of atrial transit time.

OBJECTIVE

To determine if atrial transit time is prolonged in PAF patients during SR, consistent with underlying atrial stasis.

METHOD

91 participants with PAF and 18 healthy volunteers underwent 4D flow analysis in SR. Velocity fields were produced RTDs, calculated by seeding virtual 'particles' at the right upper pulmonary vein and counting them exiting the mitral valve. An exponential decay curve quantified residence time of particles in the left atrium, and atrial stasis was expressed as the derived constant (RTD_TC) based on heartbeats. The RTD_TC was evaluated within the PAF group, and compared to healthy volunteers.

RESULTS

Patients with PAF (n = 91) had higher RTD_TC compared with gender-matched controls (n = 18) consistent with greater atrial stasis (1.68 ± 0.46 beats vs 1.51 ± 0.20 beats; p = .005). PAF patients with greater thromboembolic risk had greater atrial stasis (median RTD_TC of 1.72 beats in CHA₂DS₂-VASc≥2 vs 1.52 beats in CHA₂DS₂-VASc<2; p = .03), only female gender and left ventricular ejection fraction contributed significantly to the atrial RTD_TC (p = .006 and p = .023 respectively).

CONCLUSIONS

Atrial stasis quantified by 4D flow is greater in PAF, correlating with higher CHA₂DS₂-VASc scores. Female gender and systolic dysfunction are associated with atrial stasis. RTD offers an insight into atrial flow that may be developed to provide a personalised assessment of thromboembolic risk.

Atrial Fibrillation-Associated Ischemic Stroke Patients With Prior Anticoagulation Have Higher Risk for Recurrent Stroke

Background and Purpose—

Ischemic stroke associated with nonvalvular atrial fibrillation (NVAF) despite prior anticoagulation may indicate underlying problems that nullify the stroke-preventing effects of oral anticoagulants. We aimed to evaluate the risk for recurrent stroke in patients with NVAF with prior anticoagulation, compared with that in patients without prior anticoagulation.

Methods—

This study comprised pooled individual patient data on NVAF-associated acute ischemic stroke or transient ischemic attack from 2011 to 2014 arising from the Clinical Research Collaboration for Stroke in Korea (15 South Korean stroke centers) and the Stroke Acute Management With Urgent Risk-Factor Assessment and Improvement-NVAF registry (18 Japanese stroke centers). Data on 4841 eligible patients from the Clinical Research Collaboration for Stroke in Korea registry were pooled with data on all patients (n=1192) in the Stroke Acute Management with Urgent Risk-factor Assessment and Improvement-NVAF registry. The primary outcome was recurrent ischemic stroke. The secondary outcomes were hemorrhagic stroke and all-cause death. Outcome events were captured up to 1 year after the index event.

Results—

Among the 6033 patients in the full cohort, 5645 patients were analyzed, of whom 1129 patients (20.0%) had received prior anticoagulation. Median age was 75 years (interquartile range, 69–81 years), and 2649 patients (46.9%) were women. Follow-up data of 4617 patient-years (median follow-up 365 days, interquartile range 335–365 days) were available. The cumulative incidence of recurrent ischemic stroke in patients with prior anticoagulation was 5.3% (60/1129), compared with the 2.9% (130/4516) incidence in patients without prior anticoagulation. The risk for recurrent ischemic stroke was higher in patients with prior anticoagulation than in those without (multivariable Cox shared-frailty model, hazard ratio 1.50 [95% CI, 1.02–2.21]). No significant differences in the risks for hemorrhagic stroke and mortality were seen between the 2 groups.

Conclusions—

The risk for recurrent ischemic stroke may be higher in NVAF-associated stroke patients with prior anticoagulation than in those without prior anticoagulation.

Registration—

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01581502.

Postoperative Atrial Fibrillation Following Noncardiac Surgery Increases Risk of Stroke

BACKGROUND

New-onset postoperative atrial fibrillation is well recognized to be an adverse prognostic marker in patients undergoing noncardiac surgery. Whether postoperative atrial fibrillation confers an increased risk of stroke remains unclear.

METHODS

A systematic review and meta-analysis was performed to assess the risk of stroke after postoperative atrial fibrillation in noncardiac surgery. MEDLINE, Cochrane, and EMBASE databases were searched for articles published up to May 2019 for studies of patients undergoing noncardiac surgery that reported incidence of new atrial fibrillation and stroke. Event rates from individual studies were pooled and risk ratios (RR) were pooled using a random-effects model.

RESULTS

Fourteen studies of 3,536,291 patients undergoing noncardiac surgery were included in the quantitative analysis (mean follow-up 1.4 ± 1 year). New atrial fibrillation occurred in 26,046 (0.74%), patients with a higher incidence following thoracic surgery. Stroke occurred in 279 (1.5%) and 6199 (0.4%) patients with and without postoperative atrial fibrillation, respectively. On pooled analysis, postoperative atrial fibrillation was associated with a significantly increased risk of stroke (RR 2.51; 95% confidence interval, 1.76-3.59), with moderate heterogeneity. The stroke risk was significantly higher with atrial fibrillation following nonthoracic, compared with thoracic, surgery (RR 3.09 vs RR 1.95; P = .01).

CONCLUSION

New postoperative atrial fibrillation following noncardiac surgery was associated with a 2.5-fold increase in the risk of stroke. This risk was highest among patients undergoing nonthoracic noncardiac surgery. Given the documented efficacy of newer anticoagulants, randomized controlled trials are warranted to assess whether they can reduce the risk of stroke in these patients.

Silent atrial fibrillation: clinical management and perspectives

Silent atrial fibrillation (AF) is an asymptomatic atrial arrhythmia that can be diagnosed by chance during a systematic electrocardiogram, an external Holter, or from implanted cardiac devices. There is a significant body of the literature around silent AF, yet it remains largely underdiagnosed in everyday clinical practice. Meanwhile, new diagnostic tools have significantly improved the detection of silent AF, creating a potential for mass screening via new technologies and the promise of a major step forward in e-health progress. However, it is not yet known whether silent AF is associated with the same thromboembolic risk as symptomatic AF, and whether these asymptomatic and often short-lasting episodes therefore require anticoagulation therapy and rhythm management.