Left Atrial Size and Long-Term Risk of Recurrent Stroke After Acute Ischemic Stroke in Patients With Nonvalvular Atrial Fibrillation

Residual Risk of Recurrent Stroke Despite Anticoagulation in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis

Importance

Atrial fibrillation (AF) is a leading cause of stroke, and oral anticoagulants (OAC) reduce this risk. However, there are limited data on the residual risk of recurrent stroke in patients with AF.

Objective

To determine the recurrent stroke risk in patients with AF by performing a systematic review and meta-analysis.

Data Sources

Eligible studies were identified by searching Ovid MEDLINE and Embase from inception (Ovid: January 1946; Embase: January 1970) until January 2025.

Study Selection

Eligible studies enrolled patients with prior ischemic stroke and AF, reported information on incidence of recurrent stroke, and had follow-up data for 1 or more years. Three reviewers independently screened abstracts and performed full-text reviews.

Data Extraction and Synthesis

Data extraction was performed by 2 reviewers and independently verified by a third. Incidence rates were pooled using random-effects meta-analysis. Analysis was repeated in patients whose qualifying event occurred despite OAC. Study quality was assessed using the Quality In Prognosis Studies tool.

Main Outcomes and Measures

The primary outcome was recurrent ischemic stroke. The secondary outcomes were any recurrent stroke (ischemic stroke or intra-cerebral hemorrhage [ICH]) and ICH during follow-up.

Results

A total of 23 studies were identified, which included 78 733 patients and 140 307 years of follow-up. The median proportion of OAC use across studies was 92%. The pooled incidence of recurrent ischemic stroke was 3.75% per year (95% CI, 3.17%-4.33%). The risk was higher in noninterventional observational cohorts (4.20% per year; 95% CI, 3.41%-4.99%) compared with randomized clinical trials (2.26% per year; 95% CI, 1.96%-2.57%) (P value for interaction <.001). The risk of any recurrent stroke was 4.88% per year (95% CI, 3.87%-5.90%), and the risk of ICH was 0.58% per year (95% CI, 0.43%-0.73%). In patients with stroke despite OAC, the risk was 7.20% per year (95% CI, 5.05%-9.34%) for ischemic stroke, 8.96% per year (95% CI, 8.25%-9.67%) for any stroke, and 1.40% per year (95% CI, 0.40%-2.40%) for ICH.

Conclusions and Relevance

In this systematic review and meta-analysis, even with modern prevention therapy, the residual recurrence risk after AF-related stroke is high, with an estimated 1 in 6 patients experiencing a recurrent ischemic stroke at 5 years. These data demonstrate an urgent need to improve our understanding of the biological processes responsible for recurrence, improve risk stratification, and develop new secondary prevention strategies after AF-related stroke.

Combined Catheter Ablation and Left Atrial Appendage Occlusion in Atrial Fibrillation: From Data to Clinical Reality

PURPOSE

Atrial fibrillation (AF) requires treatment that focuses on two main goals: symptom control and prevention of thromboembolic events. Catheter ablation and left atrial appendage occlusion (LAAO) constitute two well-established treatment methods in selected patients that accomplish these two goals correspondingly. Recently, there is increasing interest in performing the two procedures concomitantly in a so-called "combined" or "one-stop" procedure. This review aims to summarize the current data on the combined procedure, from the rationale and the techniques to its clinical efficacy, indications and future directions.

METHODS

An extensive search has been conducted using the MEDLINE/PubMed database to identify the relevant studies.

RESULTS

The reported success rates of the combined procedure are very high and frequently reach 100% when performed by experienced operators. The periprocedural and follow-up complications are low, the procedure is cost-effective, while there is significant stroke, bleeding and arrhythmia incidence reduction that does not seem to be undermined by interference between the two interventions. There are also a few indications that the one-stop procedure has a positive effect on left atrial mechanical function as it has been correlated with left atrial reverse remodeling. On the other hand, some studies suggest possible increase in peri-device leaks (PDLs), compared with LAAO alone, which could in turn negatively affect the clinical outcomes. Most available studies are small and observational, with a lack of randomized controlled trials.

CONCLUSION

Catheter ablation and left atrial appendage occlusion can be safely and effectively combined in a cost-effective single procedure in carefully selected patients.

Clinical and Biomarker Determinants for Recurrent Stroke in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

Despite effective secondary prevention, including oral anticoagulant (OAC) therapy, the risk of recurrent stroke (RS) in patients with atrial fibrillation (AF) remains substantial with an annualized risk of 3.2%-6.5% per year. The reasons for this high residual risk are unclear. There is growing need for improved risk prediction tools to identify patients at greatest risk of RS in AF and to find new therapeutic targets for secondary prevention. Our objective was to perform a systematic review to investigate the association of clinical factors and echocardiographic, blood, and neuroimaging biomarkers, with stroke recurrence after AF-related stroke.

METHODS

We searched Embase/Ovid Medline until August 2023. Studies were included irrespective of OAC use. Risk ratios (RRs) were pooled using random effects. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.

RESULTS

Of 5,427 records searched, 42 reports from 28 studies including 52,798 patients (5,046 RS events during follow-up) were identified. In addition to the CHA2DS2-Vasc score (RR 1.22, 95% CI 1.15-1.30, per point) and its individual components, the clinical factors associated with recurrence were a qualifying stroke despite OAC (RR 1.55, 1.23-1.94 [vs OAC-naïve]), sustained AF (RR 1.44, 1.19-1.75 [vs paroxysmal]), hyperlipidemia (RR 1.27, 1.05-1.53), chronic kidney disease (RR 1.86, 1.19-2.92), and malignancy (RR 4.36, 1.85-10.78). NIH Stroke Scale scores (RR 0.97, 0.95-0.99) and Asian ethnicity (RR 0.59, 0.36-0.97) were associated with a reduced risk of recurrence. Known AF was not associated with a higher risk of stroke compared with AF detected after stroke (RR 1.20, 0.93-1.55). Neuroimaging markers associated with RS included chronic lacunar (RR 1.91, 1.29-2.84) or embolic-appearing (RR 2.76, 1.32-5.77) infarcts and cerebral microbleeds (RR 1.29, 1.04-1.59). Echocardiographic markers included atrial size (RR 1.40, 1.12-1.75 per cm/m2), intracardiac thrombus (RR 1.99, 1.38-2.87), spontaneous left atrial appendage (LAA) echocardiographic contrast (RR 2.91, 1.21-6.17), or low LAA intensity variation (RR 2.81, 1.48-5.32). Data were limited for blood biomarkers.

DISCUSSION

We identified several clinical factors associated with recurrence after AF-related stroke, with AF burden and stroke despite OAC of particular clinical relevance. Biomarkers of atrial cardiopathy, small vessel disease, or previous infarction were also associated with RS. Collaborative efforts are needed to identify and validate new risk factors and biomarkers of RS in AF.

Risk Factors for Silent Brain Infarction in Nonvalvular Atrial Fibrillation Patients with Low CHA2DS2-VASc Score

BACKGROUND

Silent Brain Infarction (SBI) has been found to be linked to an increased risk of cognitive impairment and future symptomatic stroke. Atrial fibrillation is a significant risk factor for SBI. Even in low-risk atrial fibrillation patients, the incidence of SBI remains high. This study aims to investigate the risk factors for SBI in nonvalvular atrial fibrillation (NVAF) patients with a CHA2DS2-VASc score of 0 to 1.

METHODS

A total of 301 consecutive low-risk NVAF patients (male: CHA2DS2-VASc=0, female: CHA2DS2-VASc=1) were enrolled. According to brain Magnetic Resonance Imaging (MRI), patients were divided into SBI (n=90) and non-SBI (n=211) groups. Baseline characteristics, blood parameters, and echocardiography results were analyzed. Multivariate logistic regression was performed to identify independent predictors. Receiver Operating Characteristic (ROC) curve analysis was used to evaluate the diagnostic power of the relevant risk factors.

RESULTS

The study revealed that neutrophil count, monocyte count, Platelet-To-Lymphocyte Ratio (PLR), neutrophil-to-high density lipoprotein cholesterol ratio (NHR), and left atrial diameter (LAD) were significantly higher in the SBI group than non-SBI group (p <0.05). Multivariate logistic regression analysis identified PLR (OR, 1.004; 95%CI 1.001-1.007; p =0.026) and LAD (OR 1.092; 95%CI 1.054-1.130; p <0.001) as the independent risk factors associated with SBI. The ROC showed that the Area Under the Curve (AUC) of PLR is 0.589 (95%CI 0.515- 0.662; p =0.015) with an optimal cut-off point of 151 (sensitivity 43.3%, specificity 74.6%). The AUC of LAD is 0.676 (95%CI 0.606-0.746; p <0.001) with an optimal cut-off point of 39 mm (sensitivity 61.1%, specificity 72.0%). The AUC of PLR combined with LAD is 0.711 (95%CI 0.646-0.777; p <0.001) with a sensitivity of 63.3% and specificity of 73.5% for SBI.

CONCLUSION

PLR and LAD can be independent risk factors for SBI in NVAF patients with low CHA2DS2-VASc scores. The combination of the two factors can enhance the predictive ability of SBI in these patients.

Predictors of left atrial appendage thrombus in atrial fibrillation patients undergoing cardioversion

BACKGROUND

Atrial fibrillation and atrial flutter represent the most prevalent clinically significant cardiac arrhythmias. While the CHA2DS2-VASc score is commonly used to inform anticoagulation therapy decisions for patients with these conditions, its predictive power is limited. Therefore, we sought to improve risk prediction for left atrial appendage thrombus (LAAT), a known risk factor for stroke in these patients.

METHODS

We developed and validated an explainable machine learning model using the eXtreme Gradient Boosting algorithm with 5 × 5 nested cross-validation. The primary outcome was to predict the probability of LAAT in patients with atrial fibrillation and atrial flutter who underwent transesophageal echocardiogram prior to cardioversion. Our algorithm used 37 demographic, comorbid, and transthoracic echocardiographic variables.

RESULTS

A total of 795 patients were included in our analysis. LAAT was present in 11.3% of the patients. The average age of patients was 63.3 years and 34.7% were women. Patients with LAAT had significantly lower left ventricular ejection fraction (29.9% vs 43.5%; p < 0.001), lower E' lateral velocity (5.7 cm vs. 7.9 cm; p < 0.001) and higher E/A ratio (2.6 vs 1.8; p = 0.002). Our machine learning model achieved a high AUC of 0.79, with a high specificity of 0.82, and modest sensitivity of 0.57. Left ventricular ejection fraction was the most important variable in predicting LAAT. Patients were split into 10 buckets based on the percentile of their predicted probability of having thrombus. The lower the percentile (e.g., 10%), the lower the probability of having thrombus. Using a cutoff point of 0.16 which includes 10.0% of the patients, we can rule out thrombus with 100% confidence.

CONCLUSION

Using machine learning, we refined the predictive power of predicting LAAT and explained the model. These results show promise in providing better guidance for anticoagulation therapy and cardioversion in AF and AFL patients.

Extended Computed Tomography Angiography for the Successful Diagnosis of Cardioaortic Thrombus in Acute Ischemic Stroke and TIA: Study Protocol for a Randomized Controlled Trial

INTRODUCTION

Cardiac imaging is one of the main components of the etiological investigation of ischemic strokes. However, basic and advanced cardiac imaging remain underused in most stroke centers globally. Computed tomography angiography (CTA) of the supra-aortic and intracranial arteries is the most frequent imaging modality applied during the evaluation of patients with acute ischemic stroke to identify the presence of a large vessel occlusion. Recent evidence from retrospective observational studies has shown a high detection of cardiac thrombi, ranging from 6.6 to 17.4%, by extending a CTA a few cm below the carina to capture cardiac images. However, this approach has never been prospectively compared against usual care in a randomized controlled trial. The Extended Computed Tomography Angiography for the Successful Screening of Cardioaortic Thrombus in Acute Ischemic Stroke and TIA (DAYLIGHT) prospective, randomized, controlled trial evaluates whether an extended CTA (eCTA) + standard-of-care stroke workup results in higher detection rates of cardiac and aortic source of embolism compared to standard-of-care CTA (sCTA) + standard-of-care stroke workup.

METHODS

DAYLIGHT is a single-center, prospective, randomized, open-blinded endpoint trial, aiming to recruit 830 patients with suspected acute ischemic stroke or transient ischemic attack (TIA) being assessed under acute code stroke at the emergency department or at a dedicated urgent stroke prevention clinic. Patients are randomized 1:1 to eCTA versus sCTA. The eCTA expands image acquisition caudally, 6 cm below the carina. All patients receive standard-of-care cardiac imaging and diagnostic stroke workup. The primary efficacy endpoint is the diagnosis of a cardioaortic thrombus after at least 30 days of follow-up. The primary safety endpoint is door-to-CTA completion time. The diagnosis of a qualifying ischemic stroke or TIA is independently adjudicated by a stroke neurologist, blinded to the study arm allocation. Patients without an adjudicated ischemic stroke or TIA are excluded from the analysis. The primary outcome events are adjudicated by a board-certified radiologist with subspecialty training in cardiothoracic radiology and a cardiologist with formal training in cardiac imaging. The primary analysis is performed according to the modified intention-to-diagnose principle and without adjustment by logistic regression models. Results are presented with odds ratios and 95% confidence intervals.

CONCLUSION

The DAYLIGHT trial will provide evidence on whether extending a CTA to include the heart results in an increased detection of cardioaortic thrombi compared to standard-of-care stroke workup.

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.

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 usefulness of global longitudinal peak strain and left atrial volume index in predicting atrial fibrillation in patients with ischemic stroke

Introduction

Detection of atrial fibrillation (AF) is crucial for preventing recurrence in patients with ischemic stroke. We aimed to examine whether the left atrial volume index (LAVI) and global longitudinal peak strain (GLPS) are associated with AF in patients with ischemic stroke.

Methods

We prospectively analyzed 678 consecutive patients with ischemic stroke. LAVI and GLPS were assessed using three-dimensional transthoracic echocardiography with speckle-tracking imaging. Multiple logistic regression was used to evaluate the association of AF with LAVI and GLPS. To evaluate the predictive value of LAVI and GLPS for the presence of AF, we used optimism-corrected c-statistics calculated by 100 bootstrap repetitions and the net reclassification improvement (NRI).

Results

The mean patient age was 68 ± 13 years (men, 60%). Patients with AF (18%) were a higher LAVI (41.7 ml/m2 vs. 74.9 ml/m2, P < 0.001) and a higher GLPS than those without AF (-14.0 vs. -17.3, P < 0.001). Among the 89 patients classified with embolic stroke of unknown source, the probable cardioembolic group had higher GLPS (n= 17, -14.6 vs. -18.6, respectively; P= 0.014) than the other groups (n= 72). Adding GLPS to age, hypertension, and the LAVI significantly improved the NRI, with an overall NRI improvement of 6.1% (P= 0.03).

Discussion

The LAVI andGLPS with speckle-tracking imaging echocardiography may help identify patients with AF.

Left atrial enlargement and high uric acid level are risk factors for left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate embolic risk assessed by CHA2DS2-VASC score

Aims

To investigate the correlation and predictive value of left atrial diameter and blood uric acid levels with the occurrence of left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate CHA₂DS₂-VASc scores.

Methods and results

A total of 849 inpatients diagnosed with atrial fibrillation who had low to moderate CHA₂DS₂-VASc scores and complete transesophageal echocardiography were included in this study. Among them, 66 patients had left atrial thrombus or dense spontaneous echo contrast. When different models were used to correct other known risk factors, acid levels and abnormal left atrial diameter were identified as additional risk factors for left atrial thrombus or dense spontaneous echo contrast. The incidence of left atrial thrombus or dense spontaneous echo contrast was higher in patients with abnormal serum uric acid levels than in the control group (12.4% vs. 5.6%, p < 0.05), and this difference persisted after correcting the baseline data with propensity score matching (10.6% vs. 4.1%, p < 0.05). Abnormal left atrial diameter was another risk factor suggested by regression analysis, with an increased incidence of left atrial thrombus or dense spontaneous echo contrast in the abnormal left atrial diameter group compared to the control group, both before (18.0% vs. 3.5%, p < 0.05) and after (15.5% vs. 5.2%, p < 0.05) propensity score matching. The best predictive value was obtained by adding both abnormal serum uric acid levels and abnormal left atrial diameter.

Conclusion

Left atrial enlargement and high uric acid levels increase the risk of left atrial thrombus or dense spontaneous echo contrast in atrial fibrillation patients with low to moderate CHA₂DS₂-VASc scores.

The contribution of competing mechanisms in stroke despite anticoagulation in patients with atrial fibrillation

BACKGROUND

For reasons poorly understood, strokes frequently occur in patients with atrial fibrillation (AF) despite oral anticoagulation. Better data are needed to inform randomised trials (RCTs) of new strategies to prevent recurrence in these patients. We investigate the relative contribution of competing stroke mechanisms in patients with AF who have stroke despite anticoagulation (OAC+) compared with those who are anticoagulant naïve (OAC-) at the time of their event.

PATIENTS AND METHODS

We performed a cross-sectional study leveraging data from a prospective stroke registry (2015-2022). Eligible patients had ischemic stroke and AF. Stroke classification was performed by a single stroke-specialist blinded to OAC status using TOAST criteria. The presence of atherosclerotic plaque was determined using duplex ultrasonography, computerised tomography (CT) or magnetic resonance (MR) angiography. Imaging was reviewed by a single reader. Logistic regression was used to identify independent predictors of stroke despite anticoagulation.

RESULTS

Of 596 patients included, 198 (33.2%) were in the OAC+ group. A competing cause for stroke was more frequent in patients with OAC+ versus OAC- (69/198 (34.8%)) versus 77/398 (19.3%), p < 0.001). After adjustment, both small vessel occlusion (odds ratio (OR): 2.46, 95% CI: 1.20-5.06) and arterial atheroma (⩾50% stenosis) (OR: 1.78, 95% CI: 1.07-2.94) were independently associated with stroke despite anticoagulation.

DISCUSSION AND CONCLUSION

Patients with AF-associated stroke despite OAC are much more likely than patients who are OAC-naïve to have competing stroke mechanisms. Rigorous investigation for alternative stroke causes in stroke despite OAC has a high diagnostic yield. These data should be used to guide patient selection for future RCTs in this population.

The effect of different preoperative left atrial appendage emptying speeds on left atrial function in patients with persistent atrial fibrillation after left atrial appendage closure combined with catheter ablation

Objective

The present study aimed to investigate whether different preoperative left atrial appendage emptying speeds (LAAEVs) have an effect on left atrial function in patients with sinus arrhythmia after left atrial appendage closure (LAAC) combined with catheter ablation (CA).

Methods

A total of 163 patients with persistent non-valvular atrial fibrillation who received combined LAAC+CA surgery were included in the present study. Regular follow-up was conducted for 12 months, and patients with complete data and successful sinus rhythm recovery were selected as the study subjects (n = 82). The patients were divided into two groups: the LAAEV < 25 cm/s group and the LAAEV ≥ 25 cm/s group (n = 41 each). The propensity score was used for matching according to gender, age, CHA₂DS₂-VASc score, and HAS-BLED score. The changes in the two groups in LA structure, storage function, conduit function, and pump function were compared.

Results

Before surgery, the maximum LA volume (LAV_max) and minimum LA volume (LAV_min) were greater in the LAAEV < 25 cm/s group than in the LAAEV ≥ 25 cm/s group. The LA storage function (eg. Ƹ and SRs), conduit function (eg. SRe), and pump function (eg. SRa) were all worse in the LAAEV < 25 cm/s group than in the LAAEV ≥ 25 cm/s group. After the combined LAAC+CA surgery, the LA storage, conduit, and pump functions improved in both groups. At 12 months after surgery, there were no statistically significant differences between the two groups.

Conclusion

Before combined LAAC+CA surgery, the LA structure and function of the LAAEV < 25 cm/s group were worse than those of the LAAEV ≥ 25 cm/s group. However, after LAAC+CA surgery, the LA structure and function of the patients were improved, and there were no significant differences between the two groups. Inferred improvement in LA structure and function in the LAAEV < 25 cm/s group was superior to that in the LAAEV ≥ 25 cm/s group.

The Atrium in Atrial Fibrillation - A Clinical Review on How to Manage Atrial Fibrotic Substrates

Atrial fibrillation (AF) is the most common sustained arrhythmia in the population and is associated with a significant clinical and economic burden. Rigorous assessment of the presence and degree of an atrial arrhythmic substrate is essential for determining treatment options, predicting long-term success after catheter ablation, and as a substrate critical in the pathophysiology of atrial thrombogenesis. Catheter ablation of AF has developed into an essential rhythm-control strategy. Nowadays is one of the most common cardiac ablation procedures performed worldwide, with its success inversely related to the extent of atrial structural disease. Although atrial substrate evaluation remains complex, several diagnostic resources allow for a more comprehensive assessment and quantification of the extent of left atrial structural remodeling and the presence of atrial fibrosis. In this review, we summarize the current knowledge on the pathophysiology, etiology, and electrophysiological aspects of atrial substrates promoting the development of AF. We also describe the risk factors for its development and how to diagnose its presence using imaging, electrocardiograms, and electroanatomic voltage mapping. Finally, we discuss recent data regarding fibrosis biomarkers that could help diagnose atrial fibrotic substrates.

Diagnostic And Prognostic Value Of Left Atrial Function In Identification Of Cardioembolism And Prediction Of Outcomes In Patients With Cryptogenic Stroke

BACKGROUND

Strokes of undetermined source, commonly termed cryptogenic stroke (CS), account for a significant proportion of ischemic stroke etiology and have high rates of stroke recurrence. The heterogeneous etiology of CS makes decisions regarding treatment for such patients challenging. We sought to evaluate the diagnostic and prognostic value of left atrial (LA) function in identification of cardioembolism and prediction of outcomes in patients with CS.

METHODS

Consecutive patients admitted to our tertiary institution with ischemic stroke or transient ischemic attack (TIA) who underwent transthoracic echocardiography were recruited with comprehensive evaluation of LA metrics including LA strain. Ischemic strokes / TIAs were classified as non-cardioembolic, cryptogenic and cardioembolic. A total of 709 patients (66.0±15.1 years, 55% male) were recruited. 291 patients had CS, 189 had non-cardioembolic stroke and 229 had cardioembolic stroke. Patients with CS were followed for 20.0±13.8 months for recurrent ischemic stroke / TIA.

RESULTS

Receiver-operating characteristic curves showed LA reservoir (LASr) and contractile (LASct) strains to be strong discriminators of cardioembolic strokes and log rank tests showed both measures to be significantly associated with the distribution of time to recurrent ischemic stroke / TIA in patients with CS. Multivariable hazards models showed LASr and LASct to be independent predictors of recurrent ischemic stroke / TIA in CS patients in addition to eGFR and active smoking.

CONCLUSIONS

LASr and LASct were strong discriminators of cardioembolic stroke and independently predicted recurrent ischemic stroke / TIA in patients with CS. Use of LA strain may improve risk stratification and decision-making in patients with CS, with particular regards to prolonged ambulatory heart rhythm monitoring and/or empiric anticoagulation.

Left Atrial Diameter in the Prediction of Thromboembolic Event and Death in Atrial Fibrillation

Background: This study aimed to determine the predictive value of left atrial diameter (LAD), and the incremental prognostic value of LAD in combination with CHA2DS2-VASc score for predicting thromboembolic event and all-cause death in patients with non-valvular atrial fibrillation (AF). Methods: This is a prospective study from 27 hospitals during 2014−2017. LADi is LAD data indexed by body surface area, and LADi in the 4th quartile (LADi Q4) was considered high. Results: A total of 2251 patients (mean age 67.4 years, 58.6% male) were enrolled. Mean follow-up duration was 32.3 months. Rates of thromboembolic events and all-cause death were significantly higher in LADi Q4 patients than in LADi Q1−3 patients (2.89 vs. 1.11 per 100 person-years, p < 0.001, and 7.52 vs. 3.13 per 100 person-years, p < 0.001, respectively). LADi Q4 is an independent predictor of thromboembolic events and all-cause death with an adjusted hazard ratio and 95% confidence interval of 1.94 (1.24−3.05) and 1.81 (1.38−2.37), respectively. LADi has incremental prognostic value on top of the CHA2DS2-VASc score with the increase in global chi-square for thromboembolism (p = 0.005) and all-cause death (p < 0.001). Conclusions: LADi is an independent predictor of thromboembolic event and has incremental prognostic value in combination with CHA2DS2-VASc score in AF patients.

Feasibility of electroanatomic mapping and radiofrequency catheter ablation in Boxer dogs with symptomatic ventricular tachycardia

Background

Treatment for Boxers with ventricular tachycardia (VT) is limited. Electroanatomic mapping (EAM) facilitates identification of arrhythmogenic substrate for radiofrequency catheter ablation (RFCA).

Objective

Describe the use of EAM to guide RFCA in Boxers with VT.

Animals

Five client‐owned Boxers with symptomatic VT or persistent VT despite antiarrhythmic medications.

Methods

Case series evaluating clinical, EAM, and before and after RFCA Holter data.

Results

Sustained VT was inducible in 3 dogs, but required aggressive stimulation protocols. Low‐voltage areas consistent with electroanatomic scar were found in 2 dogs, located at the right ventricular (RV) outflow tract and cranial RV. Two dogs had a focal activation pattern of VT and 1 dog had a reentrant mechanism. After RFCA, all dogs no longer collapsed and had fewer runs of VT, 3 of which had 0 runs of VT. Number of ventricular premature beats increased in 3 dogs and decreased in 2 dogs, 1 of which had nearly complete resolution of all arrhythmias. Procedural complications included ventricular fibrillation (n = 2) with successful defibrillation, bruising or hemorrhage at the vascular access site (n = 4), retroperitoneal hemorrhage (n = 1), aortic and mitral regurgitation (n = 1), onset of frequent supraventricular tachycardia (n = 1), and persistent right pelvic limb lameness (n = 1).

Conclusions and Clinical Importance

Electroanatomic mapping and RFCA are feasible in Boxers with VT. Based on this small cohort, RFCA may help decrease runs of VT and improve clinical signs. The anatomic substrate and electrophysiologic mechanisms are variable and require further study.

Left Atrial Strain Helps Identifying the Cardioembolic Risk in Transient Ischemic Attacks Patients with Silent Paroxysmal Atrial Fibrillation

Purpose

Patients with transient ischemic attacks often present asymptomatic and paroxysmal atrial fibrillation. Since atrial fibrillation initiates in the atria, we aimed to identify whether the abnormalities in left atrial structure and function could identify the cardioembolic etiology of the transient ischemic attacks in patients at sinus rhythm.

Patients and Methods

A total of 190 patients over 50 years old with sinus rhythm discharged after a transient ischemic attack were included in the study and divided into two groups according to the presence (group I) or absence (group II) of documented paroxysmal atrial fibrillation. The documentation of paroxysmal atrial fibrillation was based on the examination of medical registers. Cardiac ultrasound assessment was performed at a minimum of 14 days after the onset of the transient ischemic attack, to avoid assessment of atrial stunning.

Results

The group I patients were older, more frequent women, with a history of stroke or transient ischemic attack and a higher CHA2DS2-VASc score. They also presented larger left atrial volumes, lower left atrial emptying fraction, and significantly impaired left atrial deformation patterns. Multivariate logistic regression identified three variables that were independently associated with paroxysmal atrial fibrillation: age, left atrial reservoir strain, and left atrial emptying fraction (P < 0.0001). The cut-off levels for the variables were age > 55 years, reservoir strain < −17%, and emptying fraction < 51%.

Conclusion

The present study demonstrates that the LA strain is independently associated with paroxysmal atrial fibrillation in transient ischemic attack patients and might be of great help in identifying their cardioembolic etiology and preventing subsequent strokes by the initiation of anticoagulant therapy.

Applying Machine Learning to Carotid Sonographic Features for Recurrent Stroke in Patients With Acute Stroke

BACKGROUND

Although carotid sonographic features have been used as predictors of recurrent stroke, few large-scale studies have explored the use of machine learning analysis of carotid sonographic features for the prediction of recurrent stroke.

METHODS

We retrospectively collected electronic medical records of enrolled patients from the data warehouse of China Medical University Hospital, a tertiary medical center in central Taiwan, from January 2012 to November 2018. We included patients who underwent a documented carotid ultrasound within 30 days of experiencing an acute first stroke during the study period. We classified these participants into two groups: those with non-recurrent stroke (those who has not been diagnosed with acute stroke again during the study period) and those with recurrent stoke (those who has been diagnosed with acute stroke during the study period). A total of 1,235 carotid sonographic parameters were analyzed. Data on the patients' demographic characteristics and comorbidities were also collected. Python 3.7 was used as the programming language, and the scikit-learn toolkit was used to complete the derivation and verification of the machine learning methods.

RESULTS

In total, 2,411 patients were enrolled in this study, of whom 1,896 and 515 had non-recurrent and recurrent stroke, respectively. After extraction, 43 features of carotid sonography (36 carotid sonographic parameters and seven transcranial color Doppler sonographic parameter) were analyzed. For predicting recurrent stroke, CatBoost achieved the highest area under the curve (0.844, CIs 95% 0.824-0.868), followed by the Light Gradient Boosting Machine (0.832, CIs 95% 0.813-0.851), random forest (0.819, CIs 95% 0.802-0.846), support-vector machine (0.759, CIs 95% 0.739-0.781), logistic regression (0.781, CIs 95% 0.764-0.800), and decision tree (0.735, CIs 95% 0.717-0.755) models.

CONCLUSION

When using the CatBoost model, the top three features for predicting recurrent stroke were determined to be the use of anticoagulation medications, the use of NSAID medications, and the resistive index of the left subclavian artery. The CatBoost model demonstrated efficiency and achieved optimal performance in the predictive classification of non-recurrent and recurrent stroke.

Clinical impact of left atrial enlargement in Korean patients with atrial fibrillation

We sought to evaluate the clinical implication of LAE based on left atrial anterior–posterior (LA AP) dimension or LA volume index (LAVI) in Korean patients with atrial fibrillation (AF). We enrolled 8159 AF patients from the CODE-AF registry. The primary outcome was rate of stroke or systemic embolism (SSE). The prevalence of mild, moderate, and severe LAE by LA AP dimension was 30.6%, 18.5%, and 21.4%, and by LAVI (available in 5808 patients) was 15.7%, 12.5% and 37.8%, respectively. Compared with no or mild LAE, patients with significant LAE (moderate to severe LAE, n = 3258, 39.9%) were associated with a higher rate of SSE (2.5% vs. 1.4%, P = 0.001). Multivariable analysis suggested presence of significant LAE by LA AP dimension was associated with a higher risk of SSE in the overall population (HR 1.57, 95% CI: 1.14–2.17, P = 0.005) and in patients using anticoagulants (n = 5836, HR 1.79, 95% CI: 1.23–2.63, P = 0.002). Patients with significant LAE by LAVI were also at higher risk of SSE (HR 1.58, 95% CI: 1.09–2.29, P = 0.017). In conclusion, significant LAE by LA dimension or LAVI was present in 39.9% and 50.2% of AF patients, respectively, and was associated with a higher rate of SSE.

Rapid Risk Stratification of Acute Ischemic Stroke Patients in the Emergency Department: The Incremental Prognostic Role of Left Atrial Reservoir Strain

OBJECTIVES

To determine the prognostic value of positive global left atrial strain (LA-GSA+), measured by two-dimensional speckle tracking echocardiography (2D-STE) in a population of acute ischemic stroke (AIS) patients without atrial fibrillation (AF), in the setting of Emergency Department (ED).

METHODS

All consecutive AIS patients with sinus rhythm on ECG and without AF history entered this prospective study. All patients underwent complete blood tests and transthoracic echocardiography implemented with 2D-STE analysis of LA strain parameters within 6-12 h after symptoms onset. At 6-months follow-up, we evaluated the composite endpoint of all-cause mortality plus cardiovascular re-hospitalizations.

RESULTS

A total of 102 AIS patients (76.4 ± 10.8 yrs, 47% males) were prospectively included. LA-GSA+ was markedly reduced in AIS patients (20.8 ± 7.7%), without any statistically significant difference between the stroke subtypes. At 6-months follow-up, 7 deaths and 27 re-hospitalizations occurred. On multivariate Cox regression analysis, variables independently associated with outcome were: LA-GSA+ (per unit) (HR 0.29, 95% CI 0.19-0.39) and C-reactive protein (CRP) (per 0.1 mg/dl) (HR 1.45, 95% CI 1.15-1.75) as continuous variables; statin therapy (HR 0.45, 95%CI 0.28-0.62), and type 2 diabetes (HR 1.65, 95% CI 1.15-2.35) as categorical variables. A LA-GSA+ ≤20.0% predicted the occurrence of the above-mentioned outcome at 6-months follow-up with 94% sensitivity and 81% specificity (AUC=0.84). Interestingly, GSA+ showed a strong inverse correlation with CRP levels (r = -0.86).

CONCLUSIONS

A LA-GSA+ ≤20% reflects a more advanced atrial cardiomyopathy and might provide a rapid and reliable prognostic risk stratification of AIS patients without AF history in the setting of ED.

Left Atrium Assessment by Speckle Tracking Echocardiography in Cryptogenic Stroke: Seeking Silent Atrial Fibrillation

Silent atrial fibrillation (AF) may be the cause of some cryptogenic strokes (CrS). The aim of the study was to analyse atrial size and function by speckle tracking echocardiography in CrS patients to detect atrial disease. Patients admitted to the hospital due to CrS were included prospectively. Echocardiogram analysis included left atrial ejection fraction (LAEF) and atrial strain. Insertable cardiac monitor was implanted, and AF was defined as an episode of ≥1 min in the first year after stroke. Left atrial enlargement was defined as indexed volume > 34 mL/m². Seventy-five consecutive patients were included, aged 76 ± 9 years (arterial hypertension 75%). AF was diagnosed in 49% of cases. The AF group had higher atrial volume and worse atrial function: peak atrial longitudinal strain (PALs) 19.6 ± 5.7% vs. 29.5 ± 7.2%, peak atrial contraction strain (PACs) 8.9 ± 3.9% vs. 16.5 ± 6%, LAEF 46.8 ± 11.5% vs. 60.6 ± 5.2%; p < 0.001. AF was diagnosed in 20 of 53 patients with non-enlarged atrium, and in 18 of them, atrial dysfunction was present. The multivariate logistic regression analysis demonstrated an independent association between detection of AF and atrial volume, LAEF, and strain. Cut-off values were obtained: LAEF < 55%, PALs < 21.4%, and PACs < 12.9%. In conclusion, speckle tracking echocardiography in CrS patients improves silent atrial disease diagnosis, with or without atrial enlargement.

Left atrial expansion index is associated with recurrent stroke

OBJECTIVE

Although left atrial (LA) expansion index is associated with cardiovascular prognosis, whether it affects recurrent strokes is still unknown.

METHODS

This study enrolled 176 patients hospitalized with first ischemic stroke. Their stroke subtypes were classified as cardioembolic stroke (CE), noncardioembolic stroke (NCE), embolic stroke of undetermined source (ESUS), or transient ischemic attack. The LA expansion index was calculated as (Volmax-Volmin) × 100%/Volmin, where Volmax was defined as maximal LA volume and Volmin as minimal LA volume. The study endpoint was recurrent ischemic stroke.

RESULTS

Over a five-year (mean 4.9 years) follow-up period, 21 (11.9%) participants reached the study endpoint, including 10 with CE, five with NCE, and six with ESUS. The LA expansion index was lower in the event groups compared with the non-event group. For predicting recurrent stroke, LA expansion index <62.5% (76% sensitivity and 68% specificity) was superior to LA volume and E/e'. Kaplan-Meier curves revealed that the five-year cumulative recurrent stroke rate in patients with LA expansion index <62.5% was 23.9%, which was significantly higher than the five-year cumulative recurrent stroke rate of 4.6% in patients with LA expansion index >62.5% (log rank p<0.001). The LA expansion index was a significant independent predictor of recurrent stroke (hazard ratio=0.873; 95% confidence interval: 0.790-0.973 per 10% increase in LA expansion index; p=0.009).

CONCLUSION

The LA expansion index is useful for predicting recurrent stroke.

Five-Year Outcomes and Cardiac Remodeling Following Left Atrial Appendage Occlusion

Purpose

LAAO has been an alternative therapy to oral anticoagulants (OACs) for stroke prophylaxis in patients with nonvalvular atrial fibrillation (NVAF) with elevated CHA₂DS₂-Vasc score, but the long-term outcomes of LAAO and its impacts on cardiac electrical and mechanical remodeling remain to be learned. We aimed to describe the impact of left atrial appendage occlusion (LAAO) on atrial remodeling and cardiovascular outcomes within 5-year follow-up.

Patients and Methods

A total of 107 patients with nonvalvular atrial fibrillation (NVAF) undergoing LAAO in the Shanghai Tenth People’s Hospital between January 2014 and July 2017 were included. All participants were followed for ECG, transthoracic echocardiography (TTE), and clinical outcomes (including cardiovascular death, heart failure, ischemic stroke/systemic embolism, and pericardial effusion) at 6 and 12 months, and thereafter every 12 months after LAAO discharge until 5 years.

Results

After LAAO, the left atrial diameter significantly increased at 6 months (48.6 ± 6.7 vs 46.5 ± 7.0 mm); heart rate decreased immediately after the procedure (78.5 ± 14.7 vs 85.3 ± 21.7 bpm) when compared with the pre-procedure level. The QTc interval prolongated to the highest value of 460.7 ± 46.8 ms at 6 months (pre-procedure level of 433.7±49.0 ms). All these changes return to the pre-procedure level within the follow-up. For clinical outcomes, 51 patients suffered the composite of cardiovascular death (n=4, 3.7%), heart failure (n=25, 23.4%), ischemic stroke/systemic embolism (n=22, 20.6%), and pericardial effusion (n=26, 26.2%).

Conclusion

LAAO did not change ECG or TTE characteristics and nonprocedure-related pericardial effusion is common during long-term follow-up. Further studies are warranted to investigate the optimal time frame of anticoagulation in patients undergoing LAAO.

Relation of Left Atrial Enlargement to Subsequent Thromboembolic Events in Nonvalvular Atrial Fibrillation Patients With Low to Borderline Embolic Risk

The current thromboembolic risk stratification of non-valvular atrial fibrillation (NVAF) does not include parameters from transthoracic echocardiography (TTE). We hypothesized that left atrial enlargement (LAE) on TTE could discriminate who require anticoagulation therapy among NVAF patients with low/borderline clinical embolic risk. This single-center cohort study included 6,602 patients with NVAF (median age, 56 years, 70.0% male) with a low to borderline clinical embolic risk (CHA₂DS₂-VASc score: 0 to 1 in males, 1 to 2 in females). LAE was classified as mild (≥41 mm in males; ≥39 mm in females) or moderate-severe (≥47 mm in males; ≥43 mm in females). The main study outcome was thromboembolic event (ischemic stroke and systemic embolism). Mild and moderate-severe LAE was diagnosed in 26.1% and 32.9% of the cohort, respectively. The patients with moderate-severe LAE showed a higher prevalence of baseline comorbidities and valvular heart disease and had a higher incidence of thromboembolic events than patients with mild or no LAE at 2 years of follow-up (2.5% vs 1.3% vs 1.1%, respectively, p < 0.001). After multivariable adjustment, patients with moderate-severe LAE were at a higher risk of thromboembolic event (hazard ratio, 2.54; 95% CI, 1.65 to 3.90; p < 0.001) compared to those with no LAE. This result persisted in a subgroup analysis of anticoagulant-naïve patients. The rate of thromboembolic events in patients with low clinical embolic risk and moderate-severe LAE was not different to those with high clinical embolic risk without LAE. In conclusion, Moderate-severe LAE on TTE was a significant predictor of thromboembolic events in NVAF patients at low/borderline clinical embolic risk.

Implications of Inflammation and Fibrosis in Atrial Fibrillation Pathophysiology

Inflammation and fibrosis have been implicated in the pathophysiology of atrial fibrillation. Atrial fibrosis causes conduction disturbances and is a central component of atrial remodeling in atrial fibrillation. Cardiac fibroblasts, the cells responsible for fibrosis formation, are activated by inflammatory mediators and growth factors associated with systemic inflammatory conditions. Thus, inflammation contributes to atrial fibrosis; the complex interplay of these maladaptive components creates a vicious cycle of atrial remodeling progression, maintaining atrial fibrillation and increasing thrombogenicity. This review provides up-to-date knowledge regarding inflammation and fibrosis in atrial fibrillation pathophysiology and their potential as therapeutic targets.

Promising Biomarker Candidates for Cardioembolic Stroke Etiology. A Brief Narrative Review and Current Opinion

Determining the cause of stroke is considered one of the main objectives in evaluating a stroke patient in clinical practice. However, ischemic stroke is a heterogeneous disorder and numerous underlying disorders are implicated in its pathogenesis. Although progress has been made in identifying individual stroke etiology, in many cases underlying mechanisms still remain elusive. Since secondary prevention strategies are tailored toward individual stroke mechanisms, patients whose stroke etiology is unknown may not receive optimal preventive treatment. Cardioembolic stroke is commonly defined as cerebral vessel occlusion by distant embolization arising from thrombus formation in the heart. It accounts for the main proportion of ischemic strokes, and its share to stroke etiology is likely to rise even further in future decades. However, it can be challenging to distinguish cardioembolism from other possible etiologies. As personalized medicine advances, stroke researchers' focus is increasingly drawn to etiology-associated biomarkers. They can provide deeper insight regarding specific stroke mechanisms and can help to unravel previously undetected pathologies. Furthermore, etiology-associated biomarkers could play an important role in guiding future stroke prevention strategies. To achieve this, broad validation of promising candidate biomarkers as well as their implementation in well-designed randomized clinical trials is necessary. This review focuses on the most-promising candidates for diagnosis of cardioembolic stroke. It discusses existing evidence for possible clinical applications of these biomarkers, addresses current challenges, and outlines future perspectives.

Efficacy and safety of NOAC versus warfarin in AF patients with left atrial enlargement

Background

Little is known about the effects of anticoagulation in patients with atrial fibrillation (AF) and left atrial enlargement (LAE).

Methods

Data of patients with AF were retrieved from Chang Gung Research Database during 2007–2016. We excluded patients who were not using oral anticoagulants, used anticoagulants for <30 days, used ≥2 agents concomitantly or switched anticoagulants, had left atrial diameter missing from their data, were aged <65, had received valve surgeries, had mitral stenosis, or had a history of cancer. The primary outcomes were ischemic stroke (IS)/systemic embolism (SE), major bleeding, and death from any cause.

Results

We identified 40,777 patients who received a diagnosis of AF. After the exclusion criteria were applied, 6,445 patients remained, 4,922 with LAE, and they were followed up for 2.4 ±1.9 years. The mean age of the patients was 77.32 ± 0.18 in the NOAC group and 76.58 ± 6.91 in the warfarin group (p < 0.0001); 48.24% of patients in the NOAC group and 46.98% of patients in the warfarin group were men (p > 0.05). The mean CHA₂DS₂-VASc score was 3.26 ± 1.05 in the NOAC group and 3.07 ± 1.12 in the warfarin group (p < 0.0001). The mean HAS-BLED score was 3.87 ± 3.81 in the NOAC group and 3.86 ± 3.80 in the warfarin group (p > 0.05). Furthermore, the mean LA diameter was 4.75 ± 0.63 cm in the warfarin group and 4.79 ± 0.69 cm in the warfarin group (p > 0.05). Among patients with LAE, NOAC was associated with significantly reduced IS/SE events (CRR = 0.63, 95% CI = 0.52–0.77), no difference in major bleeding (CRR = 0.91, 95% CI = 0.78–1.05), and significantly reduced death from any cause (aHR = 0.65, 95% CI = 0.52–0.80) compared with warfarin.

Conclusions

In elderly patients with AF and LAE, NOAC was associated with reduced IS/SE and death from any cause compared with warfarin, whereas no difference in major bleeding was observed between these treatments.

Left Atrial Size and Ischemic Events after Ischemic Stroke or Transient Ischemic Attack in Patients with Nonvalvular Atrial Fibrillation

<b><i>Background:</i></b> The present study aimed to clarify the association between left atrial (LA) size and ischemic events after ischemic stroke or transient ischemic attack (TIA) in patients with nonvalvular atrial fibrillation (NVAF). <b><i>Methods:</i></b> Acute ischemic stroke or TIA patients with NVAF were enrolled. LA size was classified into normal LA size, mild LA enlargement (LAE), moderate LAE, and severe LAE. The ischemic event was defined as ischemic stroke, TIA, carotid endarterectomy, carotid artery stenting, acute coronary syndrome or percutaneous coronary intervention, systemic embolism, aortic aneurysm rupture or dissection, peripheral artery disease requiring hospitalization, or venous thromboembolism. <b><i>Results:</i></b> A total of 1,043 patients (mean age, 78 years; 450 women) including 1,002 ischemic stroke and 41 TIA were analyzed. Of these, 351 patients (34%) had normal LA size, 298 (29%) had mild LAE, 198 (19%) had moderate LAE, and the remaining 196 (19%) had severe LAE. The median follow-up duration was 2.0 years (interquartile range, 0.9–2.1). During follow-up, 117 patients (11%) developed at least one ischemic event. The incidence rate of total ischemic events increased with increasing LA size. Severe LAE was independently associated with increased risk of ischemic events compared with normal LA size (multivariable-adjusted hazard ratio, 1.75; 95% confidence interval, 1.02–3.00). <b><i>Conclusion:</i></b> Severe LAE was associated with increased risk of ischemic events after ischemic stroke or TIA in patients with NVAF.

Left ventricular diastolic dysfunction is associated with cerebral infarction in young hypertensive patients: A retrospective case-control study

Studies have indicated that hypertension is associated with the occurrence of acute cerebral infarction (CI) in young patients (18-45 years). However, the association between CI and left ventricular diastolic (LVD) dysfunction in young patients with hypertension has rarely been reported. The purpose of the present study was to investigate the association between LVD dysfunction and acute CI in young patients with hypertension. A total of 92 patients with acute CI who had hypertension were selected as the study group (CI group) and 98 young patients with only hypertension were selected as the control group (non-CI group). Blood pressure measurements, LVD functional assessment and cerebral MRI were performed. The χ² test was used to compare the left ventricular diastolic function between the CI and non-CI groups. The results indicated that LVD function of young patients was associated with hypertension and there was a correlation between the decrease in LVD function and the occurrence of acute CI in young patients with hypertension. The incidence of acute CI was higher in patients with decreased LVD function than in those with normal LVD function. In conclusion, hypertension in the young is associated with decreased LVD function and is a risk factor for diastolic dysfunction of the left ventricle. LVD function may be an independent predictor of acute CI in young patients with hypertension and should be considered by clinicians. By predicting the risk of acute CI in young patients with hypertension, LVD testing may aid in the primary prevention of CI or guide early treatment.

Prevalence and risk factors of silent brain infarcts in patients with AF detected by 3T-MRI

BACKGROUND

Silent brain infarcts (SBI), a finding on neuroimaging, are associated with higher risk of future stroke. Atrial Fibrillation (AF) has been previously identified as a cause of SBI.

OBJECTIVES

The aim of this study is to determine the prevalence of and risk factors for SBI in patients with AF and low-to-moderate embolic risk according to CHADS₂ and CHA₂DS₂VASc score.

METHODS

Patients with a history of AF based on medical records who scored 0-1 in the CHADS₂ score were selected from the Seville urban area using the Andalusian electronic healthcare database (DIRAYA). Demographic and clinical data were collected and a 3T brain MRI was performed on patients older than 50 years and with absence of neurological symptoms.

RESULTS

66 of the initial 443 patients (14.9%) and 41 of the 349 patients with low risk according to CHA₂DS₂VASc score (11.7%) presented at least 1 SBI. After adjusted multivariable analysis, an older age (OR 3.84, 95% CI 1.07-13.76) and left atrial (LA) enlargement (OR 3.13, 95% CI 1.15-8.55) were associated with SBI in the whole cohort, while only LA enlargement was associated with SBI in the low-risk cohort (OR 3.19, 95% CI 1.33-7.63).

CONCLUSIONS

LA enlargement on echocardiogram was associated with SBI in patients with AF and low or moderate embolic risk according to CHADS₂ and in the low-risk population according to CHA₂DS₂VASc. Although further studies are needed, a neuroimaging screening might be justified in these patients to guide medical therapies to improve stroke prevention.

Recurrent ischemic stroke in patients with atrial fibrillation ablation and prior stroke: A study based on etiological classification

BACKGROUND

Different subtypes of ischemic stroke may have different risk factors, clinical features, and prognoses. This study investigated the incidence and mode of stroke recurrence in patients with a history of stroke who underwent atrial fibrillation (AF) ablation.

METHODS

Of 825 patients who underwent AF ablation from 2006 to 2016, 77 patients (9.3%, median age 69 years) with a prior ischemic stroke were identified. Patients were classified as those with prior cardioembolic (CE) stroke (n = 55) and those with prior non-CE stroke (n = 22). The incidence and pattern of stroke recurrence were investigated.

RESULTS

The incidence of asymptomatic AF (54.5% vs 22.7%; P = .011) and left atrial volume (135.8 mL vs 109.3 mL; P = .024) was greater in the CE group than in the non-CE group. Anticoagulation treatment was discontinued at an average of 28.1 months following the initial ablation in 34 (44.2%) patients. None of the patients developed CE stroke during a median 4.1-year follow-up. In the non-CE group, 2 patients experienced recurrent non-CE stroke (lacunar infarction in 1 and atherosclerotic stroke in 1); however, AF was not observed at the onset of recurrent ischemic stroke.

CONCLUSIONS

In patients with a history of stroke who underwent catheter ablation for AF, the incidence of recurrent stroke was 0.54/100 patient-years. The previous stroke in these patients may not have been due to AF in some cases; therefore, a large-scale prospective study is warranted to identify the appro priate antithrombotic therapy for the prevention of potentially recurrent stroke.

Long-Term Outcomes of Real-World Korean Patients with Atrial-Fibrillation-Related Stroke and Severely Decreased Ejection Fraction

BACKGROUND AND PURPOSE

The clinical implications of echocardiography findings for long-term outcomes in atrial fibrillation (AF)-related stroke patients are unknown.

METHODS

This was a substudy of the Korean ATrial fibrillaTion EvaluatioN regisTry in Ischemic strOke patieNts (K-ATTENTION), which is a multicenter-based cohort comprising prospective stroke registries from 11 tertiary centers. Stroke survivors who underwent two-dimensional transthoracic echocardiography during hospitalization were enrolled. Echocardiography markers included the left-ventricle (LV) ejection fraction (LVEF), the left atrium diameter, and the ratio of the peak transmitral filling velocity to the mean mitral annular velocity during early diastole (E/e' ratio). LVEF was categorized into normal (≥55%), mildly decreased (>40% and <55%), and severely decreased (≤40%). The E/e' ratio associated with the LV filling pressure was categorized into normal (<8), borderline (≥8 and <15), and elevated (≥15). Kaplan-Meier and Cox regression analyses were performed for recurrent stroke, major adverse cardiac events, and all-cause death.

RESULTS

This study finally included 1,947 patients. Over a median follow-up of 1.65 years (interquartile range, 0.42-2.87 years), the rates of recurrent stroke, major adverse cardiac events, and all-cause death were 35.1, 10.8, and 69.6 cases per 1,000 person-years, respectively. Multivariable analyses demonstrated that severely decreased LVEF was associated with a higher risks of major adverse cardiac events [hazard ratio (HR), 3.91; 95% confidence interval (CI), 1.58-9.69] and all-cause death (HR, 1.95; 95% CI, 1.23-3.10). The multivariable fractional polynomial plot indicated that recurrent stroke might be associated with a lower LVEF.

CONCLUSIONS

Severe LV systolic dysfunction could be a determinant of long-term outcomes in AF-related stroke.

Atrial Myopathy

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The authors discuss the concept of atrial myopathy; its relationship to aging, electrophysiological remodeling, and autonomic remodeling; the interplay between atrial myopathy, AF, and stroke; and suggest how to identify patients with atrial myopathy and how to incorporate atrial myopathy into decisions about anticoagulation.

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Atrial myopathy seen in animal models of AF and in patients with AF is the result of a combination of factors that lead to electrical and structural remodeling in the atrium. Although AF may lead to the initiation and/or progression of this myopathy, the presence of AF is by no means essential to the development or the maintenance of the atrial myopathic state.

•

Methods to identify atrial myopathy include atrial electrograms, tissue biopsy, cardiac imaging, and certain serum biomarkers. A promising modality is 4-dimensional flow cardiac magnetic resonance. The concept of atrial myopathy may help guide oral anticoagulant therapy in selected groups of patients with AF, particularly those with low to intermediate risk of strokes and those who have undergone successful AF ablation. This review highlights the need for prospective randomized trials to test these hypotheses.

This paper discusses the evolving concept of atrial myopathy by presenting how it develops and how it affects the properties of the atria. It also reviews the complex relationships among atrial myopathy, atrial fibrillation (AF), and stroke. Finally, it discusses how to apply the concept of atrial myopathy in the clinical setting—to identify patients with atrial myopathy and to be more selective in anticoagulation in a subset of patients with AF. An apparent lack of a temporal relationship between episodes of paroxysmal AF and stroke in patients with cardiac implantable electronic devices has led investigators to search for additional factors that are responsible for AF-related strokes. Multiple animal models and human studies have revealed a close interplay of atrial myopathy, AF, and stroke via various mechanisms (e.g., aging, inflammation, oxidative stress, and stretch), which, in turn, lead to fibrosis, electrical and autonomic remodeling, and a pro-thrombotic state. The complex interplay among these mechanisms creates a vicious cycle of ever-worsening atrial myopathy and a higher risk of more sustained AF and strokes. By highlighting the importance of atrial myopathy and the risk of strokes independent of AF, this paper reviews the methods to identify patients with atrial myopathy and proposes a way to incorporate the concept of atrial myopathy to guide anticoagulation in patients with AF.

Determinants of postoperative left atrial structural reverse remodeling in patients undergoing combined catheter ablation of atrial fibrillation and left atrial appendage closure procedure

INTRODUCTION

Catheter ablation of atrial fibrillation (AFCA) and left atrial appendage closure (LAAC) exert opposite effects on left atrial (LA) size. We aim to observe the net impact of combined AFCA and LAAC strategy on LA size and explore those factors which might affect the postprocedure LA structural remodeling.

METHODS

A total of 53 patients, who underwent combined AFCA and Watchman LAAC in our center from March to December 2017, were enrolled. Atrial fibrillation (AF) recurrence was monitored after the procedure. Left atrial volume (LAV) and left atrial appendage volume (LAAV) were measured by Mimics based on dual-source computed tomography images.

RESULTS

At 6 months, sinus rhythm (SR) was maintained in 79.2% patients. LAV was significantly reduced (130.2 ± 36.3 mL to 107.1 ± 30.0 ml; P < .001) in SR maintenance group, but not in AF recurrence group (138.8 ± 39.3 mL to 137.9 ± 36.9 mL; P = .671). In SR group, preoperative LAAV/LAV ratio (B = -0.894; P = .015), NT-proBNP (B = 0.005; P = .019) and left ventricular ejection fraction (LVEF) (B = -0.778; P < .001) could interactively affect the extent of postoperative LA structural reverse remodeling, among which LAAV/LAV ratio could independently predict the significance of reverse remodeling (≥15% reduction in LAV) (OR, 0.56; 95% CI, 0.34-0.90; P = .018). A preoperative LAAV/LAV ratio less than 7.1% is indicative of significant LA structural reverse remodeling in this patient cohort.

CONCLUSIONS

LA structural reverse remodeling could be evidenced in patients with maintained SR following combined AFCA and LAAC. Smaller LAAV/LAV ratio, higher NT-proBNP or lower LVEF at baseline are associated with more significant LA structural reverse remodeling, while LAAV/LAV ratio can predict the significance of the process after one-stop treatment.

Multimodality Imaging for Best Dealing With Patients in Atrial Arrhythmias

The management of atrial fibrillation (AF) is not only a clinical challenge but also an imaging challenge. The role of different imaging modalities to estimate the thromboembolic risk in AF is a key clinical question. The present review summarizes the advances of myocardial imaging in the stratification of thromboembolic risk, diagnosis, and management of left atrial thrombosis in patients with AF. These imaging techniques are also important for understanding arrhythmias and their consequences. It is becoming fundamental for guiding therapy. Still, large studies are required, but be sure that left atrial imaging will become more and more clinically fundamental.

Atrial fibrillation and human immunodeficiency virus type-1 infection: a systematic review. Implications for anticoagulant and antiarrhythmic therapy

The prevalence and incidence of atrial fibrillation/flutter (AF/AFL) in patients with human immunodeficiency virus type-1 (HIV-1) infection have been poorly investigated. We performed a systematic review using PubMed and Cochrane Database of Systematic Reviews, and screening of references, searching for clinical studies reporting on the association between HIV-1 infection and AF/AFL. We also summarized the main interactions of antiretroviral agents with antithrombotic and antiarrhythmic drugs. We found a prevalence of AF/AFL ranging from 2.0% to 5.13% in patients with HIV-1, with an incidence rate of 3.6/1000 person-years. Low CD4+ count (<200-250 cells ml^-1 ) and high viral load were predictors of AF/AFL. Regarding drugs interactions, nucleoside reverse transcriptase inhibitors, integrase inhibitor and maraviroc have the lowest interactions with oral anticoagulants. Among anticoagulants, dabigatran presents the most favourable profile. Most of antiarrhythmic drugs interact with protease inhibitors, with beta blockers and diltiazem having fewer interactions. The few studies available suggest a non-negligible prevalence of AF/AFL in patients with HIV-1 infection. Awareness of potential interactions with anticoagulation and antiarrhythmic drugs is needed to offer optimal management in this population.

Prognostic value of global left atrial peak strain in patients with acute ischemic stroke and no evidence of atrial fibrillation

Prognostic stratification of acute ischemic stroke (AIS) patients without atrial fibrillation (AF) remains a challenge. Two-dimensional speckle tracking echocardiography (2D-STE) has recently been introduced for dynamic evaluation of left atrial function. However only few data are actually available regarding the application of 2D-STE in AIS patients. The aim of our study was to assess the prognostic role of global left atrial peak strain (GLAPS), measured by 2D-STE, in AIS patients without AF history. Eighty-five AIS patients (mean age 74.1 ± 12.1 years, 49 males) with normal sinus rhythm on ECG and without AF history were enrolled in the prospective study. All patients underwent a complete echocardiographic study with 2D-STE. At 1 year follow-up, we evaluated the occurrence of a composite endpoint of all-cause mortality plus cardiovascular re-hospitalizations. GLAPS was markedly reduced in AIS patients (15.71 ± 4.70%), without any statistically significant difference between the stroke subtypes. At 1-year follow-up, 14 deaths and 17 hospital readmissions were detected in AIS subjects. On a multivariate Cox model, variables independently associated with the occurrence of the composite endpoint were the "Rankin in" Scale (HR 1.69, p = 0.001), GFR (HR 0.98, p = 0.03) and the GLAPS value (HR 0.78, p < 0.0001). A GLAPS value ≤ 15.5% predicted the composite endpoint with sensitivity of 100% and specificity of 80%. A GLAPS value ≤ 15.5% reflects a more advanced atrial cardiomyopathy and might provide a reliable and useful prognostic risk stratification of AIS patients without AF history.

Safety and timing of resuming dabigatran after major gastrointestinal bleeding reversed by idarucizumab

The recent introduction of direct oral anticoagulants, including rivaroxaban, dabigatran, apixaban, and edoxaban, for the acute treatment and secondary prevention of venous thromboembolism and in atrial fibrillation has been shown to provide greater clinical benefit than oral vitamin K antagonists. However, direct oral anticoagulants are associated with adverse events, the most common being major bleeding; such events require the reversal of the anticoagulant effects by specific agents. In this case report, we describe an 87-year-old female with atrial fibrillation treated with dabigatran who had massive rectal bleeding. Idarucizumab 5 g (2 × 2.5 g/50 mL) was successfully used to reverse dabigatran effect; subsequent to this, treatment with dabigatran was resumed, and there were no further bleeding events. This suggests that dabigatran can be safely restarted after major bleeding, but this outcome needs to be confirmed in studies involving larger groups of patients.