Association of inflammatory and hemostatic markers with stroke and thromboembolic events in atrial fibrillation: a systematic review and meta-analysis

Asymmetric Dimethylarginine Is Associated with the Phenomenon of Coronary Slow Flow in Patients with Nonvalvular Atrial Fibrillation

INTRODUCTION

Coronary slow flow phenomena (CSFP) are associated with endothelial and blood component abnormalities in coronary arteries. Asymmetric dimethylarginine (ADMA) can damage the endothelium of the heart or blood vessels in patients with non-valvular atrial fibrillation (NVAF), causing changes in levels of biological indicators. Our aim was to analyze the relationship between ADMA and CSFP in NVAF patients.

METHODS

We consecutively enrolled 134 patients diagnosed with NVAF and underwent coronary angiography, 50 control patients without a history of atrial fibrillation and with normal coronary angiographic flow were included at the same time. Based on the corrected TIMI frame count (CTFC), the NVAF patients were categorized into two groups, CTFC ≤27 frames and CTFC >27 frames. Plasma ADMA, P-selectin (p-sel), von Willebrand factor (vWF), D-dimer (D-Di), plasminogen activator inhibitor 1 (PAI-1), and nitric oxide (NO) were detected by ELISA in the different groups.

RESULTS

We found that plasma ADMA levels were significantly higher among NVAF patients in the CTFC >27 grade group compared with the control or CTFC ≤27 group. In addition, the levels of blood cells and endothelium-related biomarkers (NO, P-selectin, vWF, D-Di, and PAI-1) were significantly altered and correlated with ADMA levels. Multifactorial analysis showed that plasma ADMA (odd ratio [OR; 95% CI]: 1.65 [1.21-2.43], p < 0.001) and left atrial internal diameter (OR [95% CI]: 1.04 [1.02, 1.1], p < 0.001) could be used as independent risk factors for the development of CSFP in patients with NVAF. The ROC curves of ADMA can predict the development of CSFP in NVAF patients. The minimum diagnostic concentration for the development of CSFP in patients was 2.31 µmol/L.

CONCLUSION

Our study demonstrated that CSFP in NVAF patients was associated with high levels of ADMA and left atrial internal diameter. Therefore, aggressive preoperative detection and evaluation of ADMA and left atrial internal diameter can help deal with the intraoperative presence of CSFP.

Involvement of plasminogen activator inhibitor-1 in p300/p53-mediated age-related atrial fibrosis

Plasminogen activator inhibitor-1 (PAI-1), a key regulator of the fibrinolytic system, is also intimately involved in the fibrosis. Although PAI-1 may be involved in the occurrence of atrial fibrillation (AF) and thrombosis in the elderly, but whether it participated in aging-related atrial fibrosis and the detailed mechanism is still unclear. We compared the transcriptomics data of young (passage 4) versus senescent (passage 14) human atrial fibroblasts and found that PAI-1 was closely related to aging-related fibrosis. Aged mice and senescent human and mouse atrial fibroblasts underwent electrophysiological and biochemical studies. We found that p300, p53, and PAI-1 protein expressions were increased in the atrial tissue of aged mice and senescent human and mouse atrial fibroblasts. Curcumin or C646 (p300 inhibitor), or p300 knockdown inhibited the expression of PAI-1 contributing to reduced atrial fibroblasts senescence, atrial fibrosis, and the AF inducibility. Furthermore, p53 knockdown decreased the protein expression of PAI-1 and p21 in senescent human and mouse atrial fibroblasts. Our results suggest that p300/p53/PAI-1 signaling pathway participates in the mechanism of atrial fibrosis induced by aging, which provides new sights into the treatment of elderly AF.

Mechanisms and Prediction of Ischemic Stroke in Atrial Fibrillation Patients

Atrial fibrillation (AF) is the most common arrhythmia in adults worldwide and represents an important burden for patients, physicians, and healthcare systems. AF is associated with substantial mortality and morbidity, due to the disease itself and its specific complications, such as the increased risk of stroke and thromboembolic events associated with AF. The temporal relation between AF episodes and stroke is nonetheless incompletely understood. The factors associated with an increased thromboembolic risk remain unclear, as well as the stroke risk stratification. Therefore, in this review, we intend to expose the mechanisms and physiopathology leading to intracardiac thrombus formation and stroke in AF patients, together with the evidence supporting the causal hypothesis. We also expose the risk factors associated with increased risk of stroke, the current different risk stratification tools as well as future prospects for improving this risk stratification.

Venous thromboembolism-related genetic determinant F11 rs4253417 is a potential prognostic factor in ischaemic stroke

Ischaemic stroke (IS) and venous thromboembolism (VTE) are two forms of thromboembolism that, although distinct, seem to share numerous risk factors. Concerning genetic risk factors, while many VTE genetic markers have been reported, inclusively by genome-wide association studies (GWAS), the identification and validation of genetic determinants underlying IS pathogenesis have been challenging. Considering that IS and VTE shared biological pathways and aetiological factors, the severity of IS might be also influenced by VTE-related genetic variants. Thus, the present study was designed to analyse the impact of six VTE GWAS-identified genetic variants on the clinical outcome of 363 acute IS patients. Results revealed that the single-nucleotide polymorphism (SNP) F11 rs4253417 was an independent predictor of the 5-year risk of death among patients with total anterior circulation infarct (TACI). Namely, the ones carrying the SNP C allele presented a fourfold increase in the 5-year risk of death compared to TT genotype carriers (CC/CT vs. TT; adjusted HR, 4.240; 95% CI, 1.260-14.270; P = 0.020). This SNP is known to be associated with coagulation factor XI (FXI) levels, thus with implications in haemostasis and inflammation. As such, F11 rs4253417 might be a promising prognostic biomarker among TACI patients to aid in clinical decision-making. However, additional investigation is required to confirm the study's results and dissect the underlying mechanisms.

Coagulation biomarkers for ischemic stroke

A State of the Art lecture titled "coagulation biomarkers for ischemic stroke" was presented at the International Society on Thrombosis and Haemostasis (ISTH) Congress in 2022. Ischemic stroke (IS) is a common disease with major morbidity and mortality. It is a challenge to determine which patients are at risk for IS or have poor clinical outcome after IS. An imbalance of coagulation markers may contribute to the progression and prognosis of IS. Therefore, we now discuss studies on the association of selected coagulation biomarkers from the hemostasis, inflammation, and immunothrombosis systems with the risk of IS, stroke severity at the acute phase, and clinical outcome after treatment. We report on coagulation biomarker-induced risk of IS, stroke severity, and outcomes following IS derived from prospective population studies, case-control studies, and acute-phase IS studies. We found indications that many coagulation and inflammation biomarkers are associated with IS, but it is early to conclude that any of these biomarkers can be applied in a therapeutic setting to predict patients at risk of IS, stroke severity at the acute phase, and clinical outcome after treatment. The strongest evidence for a role in IS was found for beta-thromboglobulin, von Willebrand factor, factor VIII, fibrinogen, thrombin-activatable fibrinolysis inhibitor, D-dimer, and neutrophil extracellular traps, and therefore, they are promising candidates. Further research and validation in large-size populations using well-defined study designs are warranted. Finally, we provide a selection of recent data relevant to this subject that was presented at the 2022 ISTH Congress.

[Risk factors and adherence to treatment of patients with cerebrovascular diseases]

OBJECTIVE

To assess the representation of risk factors and treatment adherence in patients with cerebrovascular diseases.

MATERIAL AND METHODS

A single-stage cross-sectional non-comparable study was conducted, which included 492 patients, of whom 133 had an ischemic stroke/transient ischemic attack (main group, MG), 344 had chronic cerebrovascular pathology (comparison group, CG). The representation of risk factors, the state of cognitive functions, the severity of anxiety and depression were evaluated.

RESULTS

MG respondents visit specialized specialists more often than CG (p<0.001), are more committed to taking antiplatelet agents (p<0.003), statins (p<0.005), antihypertensive drugs (p<0.005). Regular intake of antithrombotic drugs was associated with the history of ischemic stroke (r=0.483; p<0.01), type 2 diabetes (r=0.637; p<0.011), atrial fibrillation (r=0.481; p<0.001), living in a family (r=0.493; p<0.03). An inverse correlation was established between the systematic intake of antiplatelet drugs and the age of the respondents (r=-0.637; p<0.002), cognitive impairment (r=-0.433; p<0.05), the history of the gastrointestinal tract diseases (gastric ulcer and duodenal ulcer) (r=-0.563; p<0.001). Irregular medication intake was observed in patients aged over 60 years compared with younger (17.3% and 6.4%, respectively, p=0.001), patients living in a family compared with single (85.6% and 65.1%, p=0.032). The history of ischemic stroke or myocardial infarction is associated with increased adherence to regular medication.

CONCLUSION

The study of risk factors and the assessment of treatment adherence can ensure the formation of an effective strategy for primary and secondary prevention of cerebrovascular diseases.

Protein Biomarkers in Blood Reflect the Interrelationships Between Stroke Outcome, Inflammation, Coagulation, Adhesion, Senescence and Cancer

The most important predictors for outcomes after ischemic stroke, that is, for health deterioration and death, are chronological age and stroke severity; gender, genetics and lifestyle/environmental factors also play a role. Of all these, only the latter can be influenced after the event. Recurrent stroke may be prevented by antiaggregant/anticoagulant therapy, angioplasty of high-grade stenoses, and treatment of cardiovascular risk factors. Blood cell composition and protein biomarkers such as C-reactive protein or interleukins in serum are frequently considered as biomarkers of outcome. Here we aim to provide an up-to-date protein biomarker signature that allows a maximum of mechanistic understanding, to predict health deterioration following stroke. We thus surveyed protein biomarkers that were reported to be predictive for outcome after ischemic stroke, specifically considering biomarkers that predict long-term outcome (≥ 3 months) and that are measured over the first days following the event. We classified the protein biomarkers as immune‑inflammatory, coagulation-related, and adhesion-related biomarkers. Some of these biomarkers are closely related to cellular senescence and, in particular, to the inflammatory processes that can be triggered by senescent cells. Moreover, the processes that underlie inflammation, hypercoagulation and cellular senescence connect stroke to cancer, and biomarkers of cancer-associated thromboembolism, as well as of sarcopenia, overlap strongly with the biomarkers discussed here. Finally, we demonstrate that most of the outcome-predicting protein biomarkers form a close-meshed functional interaction network, suggesting that the outcome after stroke is partially determined by an interplay of molecular processes relating to inflammation, coagulation, cell adhesion and cellular senescence.

Right Atrial Fluorodeoxyglucose Uptake Is a Risk Factor for Stroke and Improves Prediction of Stroke Above the CHA2DS2-VASc Score in Patients With Atrial Fibrillation

Background

Atrial fibrillation (AF) is a common arrhythmia, and its most severe and dreaded complication is stroke. The CHA2DS2-VASc score is currently recommended for stroke risk assessment in AF. We aimed to explore the relationship between atrial FDG uptake and stroke and whether atrial FDG uptake could provide incremental value above the CHA2DS2-VAS score to predict stroke in AF by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT).

Materials and Methods

From September 2017 to December 2020, we retrospectively enrolled 230 patients (115 with AF and 115 without AF as the non-AF group, matched for the date of PET/CT examination and the basic characteristics of the patient) who underwent 18F-FDG PET/CT due to tumor screening or preoperative staging after prolonged fasting and followed up for at least 12 months from the date of PET/CT examination; the endpoint event is the occurrence of stroke. We visually and quantitatively analyzed 18F-FDG uptake in the right and left atria (RA/LA), right and left atrial appendage (RAA/LAA), right and left ventricle (RV/LV), and collected clinical features. In addition, according to the endpoint event (stroke), the enrolled population was divided into the stroke group and non-stroke group, and relevant clinical features and atrial FDG uptake indicators of the two groups were analyzed. Univariate and multivariate Cox regression analyzes were used to analyze the risk factors of stroke events. The Kaplan–Meier survival curve of atrial FDG uptake was drawn, and the log-rank method was used to compare the differences in the survival curves of the two groups. Receiver operating characteristic (ROC) curves were used to examine the discriminatory power of atrial FDG uptake in predicting stroke and determine whether the addition of atrial FDG uptake improves predictive value beyond the CHA2DS2-VASc score for stroke.

Results

In the AF group, more than half of patients had RA FDG uptake and one-fifth had LA FDG uptake, while one patient had RA FDG uptake and two patients had LA FDG uptake in the non-AF group. In quantitative analysis, the maximum standardized uptake value (SUVmax) of the RA and LA in the AF group was significantly higher than that of the non-AF group (all P &lt; 0.001). We followed up the patients for 28 ± 10 months, and finally, 31 patients had stroke. In the stroke group, atrial fibrillation, RA SUVmax, RAA SUVmax, LAA SUVmax, age ≥ 75 years, and left atrial dilation were significantly higher than those of the non-stroke group (all P &lt; 0.05). Multivariate Cox regression analysis showed that high RA SUVmax (RA SUVmax ≥ 2.62) was an independent risk factor for stroke (HR = 4.264, 95% CI 1.368–13.293, P = 0.012). By using the log-rank test, patients with high RA SUVmax had a significantly higher incidence of stroke compared with patients with low RA SUVmax (P &lt; 0.001). Addition of high RA SUVmax to the CHA2DS2-VASc score could predict stroke more effectively, with a larger AUC 0.790 (P &lt; 0.001).

Conclusion

This study found a significant correlation between atrial FDG uptake and AF, especially in RA. Meanwhile, RA FDG uptake is an independent risk factor for stroke, and patients with high RA SUVmax have a significantly higher risk of stroke. Moreover, RA FDG uptake improves prediction of stroke above the CHA2DS2-VASc score in patients with AF.

LncRNA SERPINB9P1 expression and polymorphisms are associated with ischemic stroke in a Chinese Han population

Long noncoding RNAs (lncRNAs) were reported to play important roles in the pathogenesis of ischemic stroke (IS). Our study aimed to investigate the role of lncRNA SERPINB9P1 expression in ischemic stroke and the association between SERPINB9P1 polymorphisms and IS risk, as well as examine the correlation of SERPINB9P1 expression and variants with clinical parameters of IS. The SERPINB9P1 levels in human participants and oxygen-glucose deprivation (OGD)-treated human A172 cells were measured by qRT-PCR. The SERPINB9P1 polymorphisms (rs375556 and rs318429) were genotyped by the MassARRAY platform. We found that the SERPINB9P1 expression was significantly downregulated in patients with IS compared with that in healthy controls. On the 14th day in the hospital, the SERPINB9P1 level in patients with moderate and severe stroke was significantly downregulated compared with the normal group. After stratification by gender, the rs375556 polymorphism was significantly associated with susceptibility to female IS in the recessive model, and the significant association remained after adjusting for age. After adjusting for gender and age, rs318429 was significantly associated with FPG and D-D levels, and rs375556 was significantly associated with INR and PTA levels in IS cases. Besides, the lncRNA SERPINB9P1 expressed downregulated in OGD/reoxygenation-treated human A172 cells. In conclusion, the lncRNA SERPINB9P1 may protect against cerebral ischemia-reperfusion injury and neurological impairment after IS. The SERPINB9P1 rs375556 polymorphism was associated with susceptibility to female IS, and SERPINB9P1 polymorphisms may influence the metabolism of blood glucose and regulation of coagulation function in patients with IS.

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

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

Left Atrial Appendage Morphology and Local Thrombogenesis-Related Blood Parameters in Patients With Atrial Fibrillation

Background

Left atrial appendage (LAA) morphology predicts stroke risk in patients with atrial fibrillation. However, it is not precisely understood how LAA morphology influences stroke risk. The present study aimed to investigate the relationship between LAA morphology and local thrombogenesis‐related blood parameters in LAA.

Methods and Results

We enrolled 205 patients undergoing catheter ablation of atrial fibrillation. The prevalence of chicken wing–, cactus‐, windsock‐, and cauliflower‐type LAAs were 23.9%, 32.7%, 29.3%, and 14.1%, respectively. Blood samples were collected from the femoral vein, left atrium, and LAA in each patient. The levels of blood parameters were tested for each blood sample. The cauliflower‐type LAA was associated with elevated platelet P‐selectin expression, and interleukin‐6 levels and with lower NO levels in LAA blood samples (P<0.05) independent of LAA flow velocity and LAA volume. LAA flow velocity, which was lowest in the cauliflower‐type LAA, was the only independent predictor of von Willebrand factor antigen and plasminogen activator inhibitor‐1 levels in LAA blood samples. In femoral vein blood samples, no significant difference was detected in the above blood parameters among the four LAA morphological types. In all blood samples, the levels of thrombin‐antithrombin complex, D‐dimer, fibrinogen, and tissue plasminogen activator were comparable among the four LAA morphological types.

Conclusions

In patients with atrial fibrillation, LAA morphological types might be associated with local platelet activity, fibrinolysis function, endothelial dysfunction, and inflammation.

Involvement of plasminogen activator inhibitor-1 and its related molecules in atrial fibrosis in patients with atrial fibrillation

Atrial fibrillation is the most common form of cardiac arrhythmia. Atrial fibrosis is a significant feature of atrial fibrillation though its mechanism is not well understood. We searched the Gene Expression Omnibus database to compare mRNA expression patterns between atrial fibrillation and sinus rhythm samples; one hundred and forty eight differentially expressed genes were identified. Most of these genes were significantly enriched in the extracellular matrix organization process and collagen-activated tyrosine kinase receptor signaling pathway. To screen hub genes involved in atrial fibrosis, we constructed a protein-protein interaction network and found that three hub genes (SERPINE1/plasminogen activator inhibitor-1/PAI-1, TIMP Metallopeptidase Inhibitor 3/TIMP3 and decorin/DCN) play vital roles in atrial fibrosis, especially plasminogen activator inhibitor-1. Elevated plasminogen activator inhibitor-1 expression was positively correlated with the p53 signaling pathway. Plasminogen activator inhibitor-1 and p53 protein expression levels were verified in patients with sinus rhythm and atrial fibrillation by Western blot analysis. Compared with the sinus rhythm controls, p53 and plasminogen activator inhibitor-1 protein expressions were upregulated in the atrial tissues of patients with atrial fibrillation. p53 was also found to regulate plasminogen activator inhibitor-1 based on the results of cellular and molecular experiments. Thus, the p53/plasminogen activator inhibitor-1 signaling axis may participate in the pathophysiological processes of atrial fibrillation, and plasminogen activator inhibitor-1 may serve as a new therapeutic biomarker in atrial fibrillation.

Stroke risk factors and outcomes among hospitalized women with atrial fibrillation

Observational cohort analyses suggest that women with atrial fibrillation (AF) endure a greater burden of stroke. We conducted an analysis of an observational cohort study completed at our tertiary care medical center to assess sex-related differences in cardiovascular risk factors, prescription of antithrombotic therapy, and 90-day outcomes. We analyzed 5000 hospitalized patients with AF: 1888 women and 3112 men. Clinical characteristics of AF, risk of stroke and bleeding, prescription of antithrombotic therapy, and 90-day clinical outcomes, including stroke and all-cause mortality, were compared. We observed a 50% higher relative frequency of stroke in hospitalized women with AF compared with men. While the frequencies of prescription of antithrombotic therapy at discharge were similar, anticoagulation was omitted in 40% of women with AF. The 90-day frequencies of major adverse events and mortality were increased in hospitalized women with AF not prescribed antithrombotic therapy at discharge. Prescription of anticoagulation in women with AF at hospital discharge was associated with a 60% and 40% relative reduction in the odds of mortality and major adverse events at 90 days. In conclusion, women hospitalized with AF have a higher risk of stroke at 90 days compared with men. Anticoagulation at hospital discharge was omitted in 40% of women with AF, but when prescribed, was associated with a reduction in mortality and major adverse events at 90 days, respectively. We analyzed 5000 hospitalized patients with atrial fibrillation (AF) (1888 women and 3112 men) in an observational cohort study completed at our tertiary care medical center to assess sex-related differences in cardiovascular risk factors, prescription of antithrombotic therapy, and 90-day outcomes. We observed a 50% higher relative frequency of stroke in hospitalized women with AF compared with men. The 90-day frequencies of major adverse events and mortality were increased in hospitalized women with AF not prescribed antithrombotic therapy at discharge. Prescription of anticoagulation in women with AF at hospital discharge was associated with a 60% and 40% relative reduction in the odds of mortality and major adverse events at 90 days.

Assessment of endogenous fibrinolysis in clinical practice using novel tests: ready for clinical roll-out?

The occurrence of thrombotic complications, which can result in excess mortality and morbidity, represent an imbalance between the pro-thrombotic and fibrinolytic equilibrium. The mainstay treatment of these complications involves the use of antithrombotic agents but despite advances in pharmacotherapy, there remains a significant proportion of patients who continue to remain at risk. Endogenous fibrinolysis is a physiological counter-measure against lasting thrombosis and may be measured using several techniques to identify higher risk patients who may benefit from more aggressive pharmacotherapy. However, the assessment of the fibrinolytic system is not yet accepted into routine clinical practice. In this review, we will revisit the different methods of assessing endogenous fibrinolysis (factorial assays, turbidimetric lysis assays, viscoelastic and the global thrombosis tests), including the strengths, limitations, correlation to clinical outcomes of each method and how we might integrate the assessment of endogenous fibrinolysis into clinical practice in the future.

Quantitatively monitoring acute ischemic stroke patients post recombinant tissue plasminogen activator treatment

BACKGROUND AND AIMS

Thrombolytic therapy is widely used to treat acute ischemic stroke (AIS) patients. As intracerebral hemorrhage is a life-threatening complication of this therapy, monitoring the fibrinolytic and coagulation systems is imperative. However, existing studies on plasmin inhibitor complex (PIC) and thrombin-antithrombin III complex (TAT) mostly apply the enzyme-linked immunosorbent assay (ELISA) method. The aim of this study is to establish the baseline of thrombolytic treatment for AIS patients; to monitor the fibrinolytic and coagulation system following alteplase administration; to ascertain the proper time point to predict intracerebral hemorrhage.

METHODS

The method used to assess a patient's intravascular situation, namely chemiluminescence, was used to quantitatively assess the PIC, TAT, and thrombomodulin (TM). Immuno-turbidimetric was used to assess the concentration of D-dimer, fibrin/fibrinogen degradation products (FDP), and the Von Willebrand factor (vWF). The Clauss clotting method was used to assay the activated partial thromboplastin time (APTT), prothrombin time (PT) and FIB.

RESULTS

PIC increased to its peak concentration at 3 hours post intravenous (IV) alteplase infusion and decreased by nearly 50% every 3 hours thereafter. After 24 hours, PIC returned to its normal range, while D-dimer and FDP decreased 3 hours later compared to PIC. PT and APTT exhibited no obvious change during the 24-hour period. TM also exhibited no changes during the treatment.

CONCLUSION

PIC decreased 3 hours earlier than D-dimer and FDP. The combined test of PIC, D-dimer, and fibrinogen can be used to monitor the fibrinolytic system after the IV alteplase infusion. The use of IV alteplase had no impact on the endothelium. Creating a patient's individual data curve could assist in the prediction of hemorrhagic transformation (HT) and a stroke occurring.

Changes in plasma concentrations of edoxaban and coagulation biomarkers according to thromboembolic risk and atrial fibrillation type in patients undergoing catheter ablation: Subanalysis of KYU-RABLE

BACKGROUND

Catheter ablation (CA) for atrial fibrillation (AF) can be associated with a risk of thromboembolism and bleeding. We recently demonstrated that uninterrupted edoxaban with one dose delayed on the CA procedural day is associated with a low risk of periprocedural complications. Previous reports have indicated that some specific subgroups of patients undergoing CA have an increased risk of bleeding and thromboembolic complications. This subanalysis of the KYU-RABLE study assessed the changes in plasma concentrations of edoxaban and coagulation biomarkers during the periprocedural period of CA in subgroups stratified by the risk of thromboembolism assessed by CHADS2 score (<2 or ≥2) and AF type (paroxysmal AF [PAF] or non-PAF).

METHODS

We evaluated changes in plasma concentrations of edoxaban and coagulation biomarkers (D-dimer and prothrombin fragment F1+2), by subgroup, during the periprocedural period of CA. Measurements were made prior to CA (procedure day).

RESULTS

This subanalysis evaluated data from 343 patients with CHADS2 score <2 and 134 patients with CHADS2 score ≥2, and from 280 patients with PAF and 197 patients with non-PAF. Plasma edoxaban concentration decreased with time on the day of CA, while plasma concentrations of coagulation biomarkers remained unchanged. No significant differences were observed according to CHADS2 score or type of AF.

CONCLUSIONS

The changes in plasma concentrations of edoxaban and coagulation biomarkers in each subgroup were similar to those of the whole analysis, regardless of the thromboembolic risk (CHADS2 <2 or ≥2) or AF type (PAF or non-PAF).

Blood-Based Biomarkers Are Associated with Different Ischemic Stroke Mechanisms and Enable Rapid Classification between Cardioembolic and Atherosclerosis Etiologies

Stroke is a top leading cause of death, which occurs due to interference in the blood flow of the brain. Ischemic stroke (blockage) accounts for most cases (87%) and is further subtyped into cardioembolic, atherosclerosis, lacunar, other causes, and cryptogenic strokes. The main value of subtyping ischemic stroke patients is for a better therapeutic decision-making process. The current classification methods are complex and time-consuming (hours to days). Specific blood-based biomarker measurements have promising potential to improve ischemic stroke mechanism classification. Over the past decades, the hypothesis that different blood-based biomarkers are associated with different ischemic stroke mechanisms is increasingly investigated. This review presents the recent studies that investigated blood-based biomarker characteristics differentiation between ischemic stroke mechanisms. Different blood-based biomarkers are specifically discussed (b-type natriuretic peptide, d-dimer, c-reactive protein, tumor necrosis factor-α, interleukin-6, interleukin-1β, neutrophil-lymphocyte ratio, total cholesterol, triglycerides, low-density lipoprotein, high-density lipoprotein and apolipoprotein A), as well as the different cut-off values that may be useful in specific classifications for cardioembolic and atherosclerosis etiologies. Lastly, the structure of a point-of-care biosensor device is presented, as a measuring tool on-site. The information presented in this review will hopefully contribute to the major efforts to improve the care for stroke patients.

Prediction-Determining Outcomes and Their Predictors in Atrial Fibrillation Patients Receiving Multicomponent Antithrombotic Therapy in Real Clinical Practice

Aim      Searching for clinical, angiographic, and biochemical predictors of cardiovascular complications (CVC) and hemorrhagic complications in patients with atrial fibrillation (AF) receiving a multicomponent antithrombotic therapy (MAT) for an elective percutaneous coronary intervention (PCI). Patients with ischemic heart disease (IHD) and AF who require MAT for PCI are at a high risk of thrombotic complications (stroke, systemic embolism, coronary events) and hemorrhage. This warrants searching for new risk factors determining prediction of the outcome.Materials and methods This study included 207 patients (146 males aged 70.1±8.3 years) with IHD and AF who received direct oral anticoagulants (DOAC) as a part of their MAT therapy. Median duration of the follow-up was 12 [8.0; 12.0] months. The efficacy endpoint was a sum of CVCs combining cardiovascular death, ischemic stroke, venous thromboembolic complications, acute coronary syndrome (ACS), and requirement for an unscheduled PCI. "Coronary events", including ACS and requirement for an unscheduled PCI were analyzed separately. The safety endpoint was BARC type 2-5 bleeding. Upon admission, biomarkers (growth-differentiation factor 15 (GDF-15), D-dimer, thrombin-activated fibrinolysis inhibitor (TAFI), and plasminogen activator inhibitor-1 (PAI-1)) were measured for all patients. Searching for prognostically significant indexes was performed with the Cox proportional hazards regression.Results Incidence of all CVCs was 16.4 %. Independent predictors of CVC included the DOAC treatment at a reduced dose (odds ratio (OR) 2.5 at 95 % confidence interval (CI) 1.02-6.15; p=0.0454), GDF-15 &gt;1191 pg /ml (OR 3.76 at 95 % CI, 1.26-11.18; p=0.0172), PAI-1 &gt;13.2 U/ml (OR 2.67 at 95 % CI, 1.13-6,26; p=0.0245). Incidence of coronary complications was 9.2 %. Independent predictors of coronary complications included a SYNTAX index &gt;26.5 (OR 4.5 at 95 % CI, 1.45-13.60; p=0.0090), PCI for chronic coronary occlusion (OR 3.21 at 95 % CI, 1.10-9.33; p=0.0326), a GDF-15 &gt;1191 pg/ml (ОR 4.70 at 95 % CI, 1.32-16.81; p=0.0172). Incidence of BARC type 2-5 bleeding was 26.1 %. The only independent predictor for hemorrhage complications was the total PRECISE-DAPT score &gt;30 (ОR 3.22; 95 % CI, 1.89-5.51; р&lt;0.0001).Conclusion      Three independent predictors of CVC were identified for patients with IHD and AF treated with MAT following an elective PCI: treatment with a reduced dose of DOAC, GDF-15 &gt;1191 pg /ml, and PAI-1&gt;13.2 U/ml. Independent predictors of coronary complications included a SYNTAX index &gt;26.5, PCI for chronic coronary occlusion, and GDF-15 &gt;1191 pg/ml. The factor associated with a risk of bleeding was the total PRECISE-DAPT score &gt;30.

Markers of coagulation and hemostatic activation aid in identifying causes of cryptogenic stroke

OBJECTIVE

To test the hypothesis that markers of coagulation and hemostatic activation (MOCHA) help identify causes of cryptogenic stroke, we obtained serum measurements on 132 patients and followed them up to identify causes of stroke.

METHODS

Consecutive patients with cryptogenic stroke who met embolic stroke of undetermined source (ESUS) criteria from January 1, 2017, to October 31, 2018, underwent outpatient cardiac monitoring and the MOCHA profile (serum D-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex, and fibrin monomer) obtained ≥2 weeks after the index stroke; abnormal MOCHA profile was defined as ≥2 elevated markers. Prespecified endpoints monitored during routine clinical visits included new atrial fibrillation (AF), malignancy, venous thromboembolism (VTE), or other defined hypercoagulable states (HS).

RESULTS

Overall, 132 patients with ESUS (mean age 64 ± 15 years, 61% female, 51% nonwhite) met study criteria. During a median follow-up of 10 (interquartile range 7-14) months, AF, malignancy, VTE, or HS was identified in 31 (23%) patients; the 53 (40%) patients with ESUS with abnormal MOCHA were significantly more likely than patients with normal levels to have subsequent new diagnoses of malignancy (21% vs 0%, p < 0.001), VTE (9% vs 0%, p = 0.009), or HS (11% vs 0%, p = 0.004) but not AF (8% vs 9%, p = 0.79). The combination of 4 normal MOCHA and normal left atrial size (n = 30) had 100% sensitivity for ruling out the prespecified endpoints.

CONCLUSION

The MOCHA profile identified patients with cryptogenic stroke more likely to have new malignancy, VTE, or HS during short-term follow-up and may be useful in direct evaluation for underlying causes of cryptogenic stroke.

Similar thrombolysis outcomes in acute stroke patients with and without atrial fibrillation if pre-stroke CHA2DS2-VASc score is low: A retrospective study

The prognosis of acute ischemic stroke patients treated with intravenous (IV) recombinant tissue plasminogen activator (rtPA) is poorer in patients with atrial fibrillation (AF) than patients without AF, which might be related to the greater stroke severity in AF patients. Higher pre-stroke CHA2DS2-VASc scores are associated with greater stroke severity and poorer outcomes. AF Patients tend to have higher CHA2DS2-VASc scores than the non-AF patients. We thus hypothesized that pre-stroke CHA2DS2-VASc scores can be used to improve outcome stratification of IV thrombolysis therapy in acute stroke patients with and without AF. We retrospectively enrolled ischemic stroke patients who received IV-rtPA and categorized them into 2 groups: low-risk (CHA2DS2-VASc scores ≤ 2) and high-risk (CHA2DS2-VASc scores ≥ 3) groups. We compared the outcomes between AF and non-AF patients and the interactive effects of the levels of CHA2DS2-VASc scores on this outcome difference. In the low-risk group, there was no difference in outcomes between the AF and non-AF patients. In the high-risk group, the AF patients had worse outcomes at 3 and 6 months. Our results suggest that pre-stroke CHA2DS2-VASc scores are a useful outcome predictor of IV thrombolytic therapy in acute stroke patients with AF.

Prognostic value of von Willebrand factor for patients with atrial fibrillation: a meta-analysis of prospective cohort studies

BACKGROUND

It is unknown whether an abnormal level of von Willebrand factor (vWF) is correlated with the prognosis of patients with atrial fibrillation (AF) and current findings are controversial. This meta-analysis aimed to evaluate the association between vWF levels and the clinical prognosis of patients with AF.

METHODS

We searched prospective cohort studies on PubMed, Embase, Web of Science, Cochrane Library and WanFang databases for vWF and adverse events of AF from inception of the databases to July 2019. The risk ratios of all-cause death, cardiovascular death, major adverse cardiac events (MACE), stroke and bleeding prognosis in patients with AF were analysed using a fixed-effects model or random-effects model, and all included studies were evaluated with heterogeneity and publication bias analysis.

RESULTS

Twelve studies which included 7449 patients with AF were used in the meta-analysis. The average age was 71.3 years and the average follow-up time was 3.38 years. The analysis found that high vWF levels were associated with increased risks of all-cause death (RR 1.56; 95% CI 1.16 to 2.11, p=0.00400), cardiovascular death (RR 1.91; 95% CI 1.20 to 3.03, p=0.00600), MACE (RR 1.83; 95% CI 1.28 to 2.62, p=0.00090), stroke (RR 1.69; 95% CI 1.08 to 2.64, p=0.02000) and bleeding (RR 2.01; 95% CI 1.65 to 2.45, p<0.00001) in patients with AF.

CONCLUSIONS

vWF is a risk factor for poor prognosis of AF, and patients with higher vWF levels have a higher risk of all-cause death, cardiovascular death, MACE, stroke and bleeding.

Clot Lysis Time Predicts Stroke During Anticoagulant Therapy in Patients with Atrial Fibrillation

BACKGROUND

Formation of dense fibrin clots has been reported in both atrial fibrillation (AF) and ischemic stroke. We have previously demonstrated that such clot properties can predict thromboembolism and major bleeding in AF patients treated with vitamin K antagonists (VKAs). In this longitudinal cohort study, we evaluated whether impaired fibrinolysis is associated with clinical outcomes in AF.

METHODS

In 236 patients with AF receiving VKAs, we measured ex vivo plasma clot lysis time (CLT), a measure of global fibrinolysis along, with von Willebrand factor antigen (vWF), plasminogen activator inhibitor 1 antigen (PAI-1), and other fibrinolysis modulators. The primary outcome were ischemic cerebrovascular events. Secondary end points were death and major bleeding.

RESULTS

During a median follow-up time of 4.3 (interquartile range 3.7-4.8) years, annual rates of death, ischemic cerebrovascular events, and major bleeding were 1.48%, 2.96%, and 3.45%, respectively. Patients with CLT in the fourth quartile (> 115 min) had 8-fold higher stroke or transient ischemic attack (TIA) rates compared with the other patients (8.67% vs 1.1%; P < 0.0001). CLT correlated with PAI-1 and vWF (r = 0.59; P < 0.0001 for both). In the multivariate Cox regression analysis adjusted for potential confounders, the independent predictors of stroke or TIA were CLT > 115 minutes (hazard ratio [HR] 7.67, 95% confidence interval [CI] 2.78-21.17; P < 0.0001), PAI-1 (HR 1.16, 95% 1.05-1.28; P = 0.003), and CHA₂DS₂-VASc score ≥3 (HR 5.18, 95% 1.76-15.29; P = 0.003). CLT was not associated with death or major and minor bleeding events.

CONCLUSIONS

Impaired fibrinolysis may predict thromboembolic events in AF patients receiving VKA.

Atrial fibrillation in cryptogenic stroke and transient ischaemic attack - The Nordic Atrial Fibrillation and Stroke (NOR-FIB) Study: Rationale and design

Purpose

Paroxysmal atrial fibrillation is often suspected as a probable cause of cryptogenic stroke. Continuous long-term ECG monitoring using insertable cardiac monitors is a clinically effective technique to screen for atrial fibrillation and superior to conventional follow-up in cryptogenic stroke. However, more studies are needed to identify factors which can help selecting patients with the highest possibility of detecting atrial fibrillation with prolonged rhythm monitoring. The clinical relevance of short-term atrial fibrillation, the need for medical intervention and the evaluation as to whether intervention results in improved clinical outcomes should be assessed.

Method

The Nordic Atrial Fibrillation and Stroke Study is an international, multicentre, prospective, observational trial evaluating the occurrence of occult atrial fibrillation in cryptogenic stroke and transient ischaemic attack. Patients with cryptogenic stroke or transient ischaemic attack from the Nordic countries are included and will have the Reveal LINQ® Insertable cardiac monitor system implanted for 12 months for atrial fibrillation detection. Biomarkers which can be used as predictors for atrial fibrillation and may identify patients, who could derive the most clinical benefit from the detection of atrial fibrillation by prolonged monitoring, are being studied.

Conclusion

The primary endpoint is atrial fibrillation burden within 12 months of continuous rhythm monitoring. Secondary endpoints are atrial fibrillation burden within six months, levels of biomarkers predicting atrial fibrillation, CHA₂DS₂-VASc score, incidence of recurrent stroke or transient ischaemic attack, use of anticoagulation and antiarrhythmic drugs, and quality of life measurements. The clinical follow-up period is 12 months. The study started in 2017 and the completion is expected at the end of 2020.

Coagulation markers and echocardiography predict atrial fibrillation, malignancy or recurrent stroke after cryptogenic stroke

We evaluated the utility of left atrial volume index (LAVI) and markers of coagulation and hemostatic activation (MOCHA) in cryptogenic stroke (CS) patients to identify those more likely to have subsequent diagnosis of atrial fibrillation (AF), malignancy or recurrent stroke during follow-up.Consecutive CS patients who met embolic stroke of undetermined source (ESUS) who underwent transthoracic echocardiography and outpatient cardiac monitoring following stroke were identified from the Emory cardiac registry. In a subset of consecutive patients, d-dimer, prothrombin fragment 1.2, thrombin-antithrombin complex and fibrin monomer (MOCHA panel) were obtained ≥2 weeks post-stroke and repeated ≥4 weeks later if abnormal; abnormal MOCHA panel was defined as ≥2 elevated markers which did not normalize when repeated. We assessed the predictive abilities of LAVI and the MOCHA panel to identify patients with subsequent diagnosis of AF, malignancy, recurrent stroke or the composite outcome during follow-up.Of 94 CS patients (mean age 64 ± 15 years, 54% female, 63% non-white, mean follow-up 1.4 ± 0.8 years) who underwent prolonged cardiac monitoring, 15 (16%) had new AF. Severe LA enlargement (vs normal) was associated with AF (P < .06). In 42 CS patients with MOCHA panel testing (mean follow-up 1.1 ± 0.6 years), 14 (33%) had the composite outcome and all had abnormal MOCHA. ROC analysis showed LAVI and abnormal MOCHA together outperformed either test alone with good predictive ability for the composite outcome (AUC 0.84).We report the novel use of the MOCHA panel in CS patients to identify a subgroup of patients more likely to have occult AF, occult malignancy or recurrent stroke during follow-up. A normal MOCHA panel identified a subgroup of CS patients at low risk for recurrent stroke on antiplatelet therapy. Further study is warranted to evaluate whether the combination of an elevated LAVI and abnormal MOCHA panel identifies a subgroup of CS patients who may benefit from early anticoagulation for secondary stroke prevention.

Is von Willebrand factor associated with stroke and death at mid-term in patients with non-valvular atrial fibrillation?

BACKGROUND

Heart failure and atrial fibrillation share common mechanisms that may contribute to hypercoagulability and thrombotic risk. Elevated von Willebrand factor (vWF) concentration has been associated with increased risk of thromboembolism and cardiovascular events.

AIM

To investigate whether increased vWF plasma concentration predicts occurrence of a composite endpoint (all-cause death and stroke) in patients with non-valvular atrial fibrillation (NVAF).

METHODS

We prospectively studied 122 patients (mean age 70±14years; 46% men) hospitalized with NVAF, and followed over a median (interquartile range) of 5.4 (2.3-9.0)years. Cox proportional models were used to estimate the association of vWF concentration with time to stroke and death.

RESULTS

Forty-three patients (35%) had at least a stroke or died during the 5-year follow-up. Kaplan-Meier curves using vWF plasma concentration tertiles (≤191IU/dL;>191 to≤295IU/dL;>295IU/dL) showed that vWF plasma concentrations discriminated groups of patients with higher cardiovascular event rates (log-rank P=0.01). In the multivariable analysis, higher vWF concentrations (middle tertile hazard ratio [HR] 4.59, 95% confidence interval [CI] 1.55-13.50 [P=0.006]; upper tertile HR 4.10, 95% CI 1.43-11.75 [P=0.009]), age≥75years (HR 5.02, 95% CI 1.53-16.49; P=0.008), heart failure (HR 2.05, 1.01-4.19; P=0.048), C-reactive protein, log₂ per unit increase (HR 1.29, 95% CI 1.04-1.61; P=0.021), no warfarin at discharge (HR 4.96, 95% CI 2.02-12.20; P<0.0001) and no aspirin at discharge (HR 4.41, 95% CI 1.71-11.97; P=0.002) were independently associated with an increased risk of stroke and all-cause death, whereas female sex was a protective factor (HR 0.35, 0.16-0.78; P=0.01).

CONCLUSIONS

High vWF plasma concentrations may discriminate patients with NVAF at greater risk of stroke or all-cause death.

Factor Xa inhibition by rivaroxaban regulates fibrogenesis in human atrial fibroblasts with modulation of nitric oxide synthesis and calcium homeostasis

BACKGROUND

Rivaroxaban, a widely used factor Xa inhibitor in reducing stroke in atrial fibrillation (AF) patients has multiple biological effects with activation of protease-activated receptor (PAR) signaling. Atrial fibrosis plays a critical role in the pathophysiology of AF. In this study, we evaluated whether rivaroxaban regulates atrial fibroblast activity and its underlying mechanisms.

METHODS AND RESULTS

Migration, proliferation analyses, nitric oxide (NO) production assay, calcium fluorescence imaging, and western blots were conducted in human atrial fibroblasts with or without rivaroxaban (100 nmol/L or 300 nmol/L) and co-administration of L-NAME (L-NG-nitro arginine methyl ester, 100 μmol/L), EGTA (Ethylene glycol tetra-acetic acid, 1 mmol/L), thrombin (0.5 U/mL), PAR1 agonist peptide (TFLLR-NH2, 100 μmol/L), PAR1 inhibitor (SCH79797, 0.5 μmol/L) and PAR2 inhibitor (GB83, 10 μmol/L). Atrial fibrosis was examined in isoproterenol (100 mg/kg, subcutaneous injection)-treated rats with or without rivaroxaban (10 mg/kg/day orally for 14 consecutive days). Rivaroxaban reduced the migration, pro-collagen type I production, and proliferation of atrial fibroblasts. Rivaroxaban decreased phosphorylated endothelial NO synthase (eNOS) (Thr 495, an inhibitory phosphorylated site of eNOS), and calcium (Ca²⁺) entry, and increased NO production. Moreover, L-NAME blocked the effects of rivaroxaban on fibroblast collagen and NO production. In the presence of EGTA, the migratory capability was similarly decreased in atrial fibroblasts with and without treatment with rivaroxaban (100 nmol/L), which suggests that rivaroxaban decreases migratory capability of atrial fibroblasts by inhibiting Ca²⁺ entry. Additionally, rivaroxaban significantly attenuated the effects of thrombin, and TFLLR-NH2 on migratory, proliferative, and pro-collagen type I production capability in atrial fibroblasts. SCH79797 or GB83 decreased pro-collagen type I production, migration, and proliferation capability in fibroblasts, but combined SCH79797 or GB83 with and without rivaroxaban had similar fibroblast activity. Moreover, rivaroxaban significantly decreased atrial fibrosis in isoproterenol-treated rats.

CONCLUSIONS

Rivaroxaban (100-300 nmol/L) regulates atrial fibroblast activity and atrial fibrosis by increasing NO production and decreasing Ca²⁺ entry through inhibition of PAR signaling.

Prognostic value of von Willebrand factor in patients with atrial fibrillation: A meta-analysis

BACKGROUND

Studies on the prognostic role of von Willebrand factor (vWF) in patients with atrial fibrillation (AF) are conflicting. This meta-analysis aimed to evaluate the association of elevated circulating vWF level with adverse outcomes in patients with AF.

METHODS

PubMed and Embase were used to search literature through August 2017. Prospective observational studies that evaluated the association of elevated vWF level with major adverse cardiac events (MACEs) and all-cause mortality in patients with AF were deemed eligible. The MACEs included death, stroke/transient ischemic attack, heart failure, myocardial infarction, and systemic/peripheral embolism.

RESULTS

A total of 6 studies were included this meta-analysis. Patients with AF with the highest vWF level were independently associated with greater risk of MACEs (risk ratio [RR] 2.20; 95% confidence intervals [CI] 1.61-3.01) and all-cause mortality (RR 1.63; 95% CI 1.39-1.91). Subgroup analysis showed that the prognostic role of higher vWF level was consistently observed in each defined subgroups.

CONCLUSION

Patients with AF with elevated vWF level are independently associated with a higher risk of MACEs and all-cause mortality. However, more well-designed prospective studies are needed to confirm these findings.

Platelet function and microparticle levels in atrial fibrillation: Changes during the acute episode

BACKGROUND

Thrombotic risk constitutes a major complication of atrial fibrillation (AF). Platelets and microparticles (MPs) are important for hemostasis and thrombosis, however their participation during AF is not well known. The aim of this study was to characterize platelet function and MPs procoagulant and fibrinolytic activity in AF patients and to determine the effects of an acute-AF episode.

METHODS

Blood was collected from paroxysmal (21) and persistent (16) AF patients referred for AF catheter ablation. Ten patients in sinus rhythm for 10days were induced in AF allowing comparisons of left atrium samples before and after induction. Platelet aggregation with ADP, TRAP, collagen, and ristocetin was studied. Platelet surface expression of PAR-1, αIIbβ3, GPIb and P-selectin were evaluated by flow cytometry, and MPs-associated procoagulant and fibrinolytic activity levels were determined by functional assays.

RESULTS

A specific reduction in platelet aggregation to TRAP, activating the thrombin receptor PAR-1, was found in all AF patients. No differences in platelet receptor expression were found. Yet, after acute-induced AF, the platelet response was improved. Furthermore, a significant decrease of left atrium tissue factor-dependent procoagulant activity of MPs was observed.

CONCLUSION

Acute episodes of AF results in a decrease in MPs-associated tissue factor activity, possibly corresponding to consumption, which in turn favors coagulation and the local production of thrombin. A decreased platelet basal aggregation to TRAP may result from PAR1 desensitization, whereas the improved response after an induced episode of AF suggests activation of coagulation and PAR1 re-sensitization.

Fibrinolytic Deficit and Platelet Activation in Atrial Fibrillation and Their Postablation Modulation

This study aims to examine the effects of atrial fibrillation (AF) on the expression of the cellular mediators plasminogen activator inhibitor 1 (PAI-1) and CD40 ligand (CD40-L). Additionally, the effect of catheter ablation on the levels of the aforementioned biomarkers was also examined. In this prospective study, plasma samples were collected from patients with AF at baseline prior to ablation and at 1 and 3 months postablation. There was a statistically significant increase in CD40-L at baseline in patients with AF compared to control ( P = .0034). There was a statistically significant decrease in CD40-L levels postablation at both 1 month ( P < .0001) and 3 months ( P < .0001) compared to baseline. Baseline levels of PAI-1 were elevated compared to the control group (mean 19.55 ± 2.17 ng/mL vs 4.85 ± 0.41 ng/mL) and a statistically significant decrease in circulating PAI-1 levels 1 month postablation ( P = .05) was noted compared to preablation levels. These data suggest that inflammation plays an important role in the pathogenesis of AF and that these cellular mediators are modulated by catheter ablation.

Effect of sinus rhythm restoration on markers of thrombin generation in atrial fibrillation

Background

Atrial fibrillation (AF) confers a hypercoagulable state; however, it is not clear whether restoration of sinus rhythm is associated with normalisation of markers of thrombogenesis. We studied the impact of sustained sinus rhythm on prothrombotic markers, and their predictive abilities in foreseeing rhythm outcome after cardioversion.

Methods

In a double blind, placebo-controlled study, 171 patients referred for electrical cardioversion of persistent AF were randomised to receive candesartan or placebo for 3-6 weeks before and 6 months after cardioversion. Endogenous thrombin potential (ETP), prothrombin fragment 1 + 2 (F1 + 2) and D-dimer were measured before cardioversion and at end of study. These markers were also measured in a reference group comprising 49 subjects without AF.

Results

The markers remained unchanged in those 28 patients who maintained sinus rhythm. Discontinuation of warfarin treatment in a subset of 13 low-risk patients in sinus rhythm was associated with significantly higher levels of D-dimer and F1 + 2 compared to the reference group; D-dimer (456 ng/mL (276, 763) vs. 279 ng/mL (192, 348), p = 0.002) and F1 + 2 (700 pmol/L (345, 845) vs. 232 pmol/L (190, 281), p < 0.001). None of the markers were associated with rhythm outcome after electrical cardioversion.

Conclusions

Sustained sinus rhythm for 6 months after cardioversion for AF had no impact on ETP, F1 + 2 or D-dimer levels. Discontinuation of warfarin in low-risk patients with sustained sinus rhythm was associated with significantly higher levels of D-dimer and F1 + 2 compared to the reference group. Our results suggest persistent hypercoagulability in AF patients despite long-term maintenance of sinus rhythm.

Trial registration

The CAPRAF study was registered at clinicaltrials.gov (NCT00130975) in August 2005.

Long-Term Stroke Risk Prediction in Patients With Atrial Fibrillation: Comparison of the ABC-Stroke and CHA2DS2-VASc Scores

BACKGROUND

The ABC-stroke score (age, biomarkers [N-terminal fragment B-type natriuretic peptide, high-sensitivity troponin], and clinical history [prior stroke/transient ischemic attack]) was proposed to predict stroke in atrial fibrillation (AF). This score was derived/validated in 2 clinical trial cohorts in which patients with AF were highly selected and carefully followed-up. However, the median follow-up was 1.9 years in the trial cohort; therefore, its long-term predictive performance remains uncertain. This study aimed to compare the long-term predictive performances of the ABC-stroke and CHA2DS2-VASc (cardiac failure or dysfunction, hypertension, age ≥75 [doubled], diabetes mellitus, stroke [doubled]-vascular disease, age 65 to 74 years and sex category [female]) scores in a cohort of anticoagulated patients with AF.

METHODS AND RESULTS

We recruited 1125 consecutive patients with AF who were stable on vitamin K antagonists and followed-up for a median of 6.5 years. ABC-stroke and CHA2DS2-VASc (cardiac failure or dysfunction, hypertension, age ≥75 [doubled], diabetes mellitus, stroke [doubled]-vascular disease, age 65 to 74 years and sex category [female]) scores were calculated and compared. Median CHA2DS2-VASc and ABC-stroke scores were 4 (interquartile range 3-5) and 9.1 (interquartile range 7.3-11.3), respectively. There were 114 ischemic strokes (1.55% per year) at 6.5 years. The C-index of ABC-stroke at 3.5 years was significantly higher than CHA2DS2-VASc (0.663 versus 0.600, P=0.046), but both C-indexes were nonsignificantly different at 6.5 years. Integrated discrimination improvement showed a small improvement (<2%) in sensitivity at 3.5 and 6.5 years with ABC-stroke. For ABC-stroke, net reclassification improvement was nonsignificantly different at 3.5 years, and showed a negative reclassification at 6.5 years compared with CHA2DS2-VASc. Decision curve analyses did not show a marked improvement in clinical usefulness of the ABC-stroke score over the CHA2DS2-VASc score.

CONCLUSIONS

In anticoagulated patients with AF followed-up over a long-term period, the novel ABC-stroke score does not offer significantly better predictive performance compared with the CHA2DS2-VASc score.

Pre-stroke glycemic control is associated with early neurologic deterioration in acute atrial fibrillation-related ischemic stroke

Background

It has been suggested that AF-related ischemic stroke (IS) that is accompanied by atherosclerotic burden have poorer outcomes. The aim of this study was to investigate the importance of pre-stroke glycemic control (PSGC) on the early neurologic deterioration (END) of patients with acute AF-related IS.

Methods

We retrospectively recruited 121 patients with AF-related IS who also had Diabetes mellitus (DM). The HbA1C level was measured in all subjects. END was defined as an increase in the National Institute of Health Stroke Scale (NIHSS) score of 4 NIHSS points within 7 days of symptom onset compared to the initial NIHSS score.

Results

In this study, 20.7% (25 patients) were classified as having a poor PSGC status with a HbA1C level above 8.0%. In the univariate analysis, a poor PSGC status (p < 0.01), smoking (p = 0.01), severe neurologic deficits at admission (p = 0.01), and a larger size of ischemic lesions on DWI (p < 0.01) were associated with the occurrence of END. In the multivariate model, a poor PSGC status (p = 0.02) and larger size of ischemic lesions on MRI (p < 0.01) were independent predictors of END in acute AF-related IS.

Conclusion

The HbA1c level upon admission was independently associated with significant prediction of END in acute AF-related IS.

Predictive performance of the CHA2DS2-VASc rule in atrial fibrillation: a systematic review and meta-analysis

Essentials The widely recommended CHA2DS2-VASc shows conflicting results in contemporary validation studies. We performed a systematic review and meta-analysis of 19 studies validating CHA2DS2-VASc. There was high heterogeneity in stroke risks for different CHA2DS2-VASc scores. This was not explained by differences between setting of care, or by performing meta-regression.

SUMMARY

Background The CHA2DS2-VASc decision rule is widely recommended for estimating stroke risk in patients with atrial fibrillation (AF), although validation studies show ambiguous and conflicting results. Objectives To: (i) review existing studies validating CHA2DS2-VASc in AF patients who are not (yet) anticoagulated; (ii) meta-analyze estimates of stroke risk per score; and (iii) explore sources of heterogeneity across the validation studies. Methods We performed a systematic literature review and random effects meta-analysis of studies externally validating CHA2DS2-VASc in AF patients not receiving anticoagulants. To explore between-study heterogeneity in stroke risk, we stratified studies to the clinical setting in which patient enrollment started, and performed meta-regression. Results In total, 19 studies were evaluated, with over two million person-years of follow-up. In studies recruiting AF patients in hospitals, stroke risks for scores of 0, 1 and 2 were 0.4% (approximate 95% prediction interval [PI] 0.2-3.2%), 1.2% (95% PI 0.1-3.8%), and 2.2% (95% PI 0.03-7.8%), respectively. These were consistently higher than those in studies recruiting patients from the open general population, with risks of 0.2% (95% PI 0.0-0.9%), 0.7% (95% PI 0.3-1.2%) and 1.5% (95% PI 0.4-3.3%) for scores of 0, 1, and 2, respectively. Heterogeneity, as reflected by the wide PIs, could not be fully explained by meta-regression. Conclusions Studies validating CHA2DS2-VASc show high heterogeneity in predicted stroke risks for different scores.

Antiplatelet Therapy Combinations and Thrombogenicity in Patients with Non-Valvular Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Combination antiplatelet therapy reduces the risk of ischemic stroke compared with aspirin monotherapy in non-valvular atrial fibrillation (NVAF) patients. The underlying mechanism, however, remains unclear. In addition, the association between platelet inhibition and thrombogenicity in NVAF has not been evaluated.

SUBJECTS AND METHODS

We randomized 60 patients with NVAF that were taking 100 mg of aspirin daily (>1 month) to adding 75 mg of clopidogrel daily (CLPD group), 100 mg of cilostazol twice daily (CILO group), or 1000 mg of omega-3 polyunsaturated fatty acid twice daily (PUFA group). Biomarkers (von Willebrand factor antigen [vWF:Ag], fibrinogen, D-dimer, and high-sensitivity C-reactive protein [hs-CRP]) and platelet reactivity (PR), which were the levels stimulated by adenosine diphosphate (ADP), thrombin-receptor agonist peptide, collagen, and arachidonic acid, were measured at baseline and 30-day follow-up.

RESULTS

Combination antiplatelet therapy significantly reduced vWF:Ag and fibrinogen levels (7.7 IU/dL, p=0.015 and 15.7 mg/dL, p=0.005, respectively), but no changes were found in D-dimer and hs-CRP levels. The CLPD and CILO groups showed fibrinogen and vWF:Ag level reductions (24.9 mg/dL, p=0.015 and 9.3 IU/dL, p=0.044, respectively), whereas the PUFA group did not show any differences in biomarkers. Irrespective of regimen, the changes in fibrinogen and vWF:Ag levels were mainly associated with the change in ADP-mediated PR (r=0.339, p=0.008 and r=0.322, p=0.012, respectively).

CONCLUSION

In patients with NVAF, combination antiplatelet therapy showed reductions for vWF:Ag and fibrinogen levels, which may be associated with the inhibitory levels of ADP-mediated PR. The clinical implications of these findings need to be evaluated in future trials.

Elevated NT-proBNP is associated with unfavorably altered plasma fibrin clot properties in atrial fibrillation

BACKGROUND

Dense fibrin clot formation and hypofibrinolysis have been reported in atrial fibrillation (AF). It is unclear which factors affect fibrin clot properties in AF.

METHODS AND RESULTS

We investigated plasma fibrin clot permeability (K_s), clot lysis time (CLT), endogenous thrombin potential (ETP) as well as other coagulation and fibrinolysis parameters along with N-terminal pro-B-type natriuretic peptide (NT-proBNP) in 160 AF patients (median age, 70.5years). Previous stroke (n=15; 9.4%) was associated with decreased K_s (P=0.04) and longer CLT (P=0.005), together with higher antiplasmin (P=0.03) and lower tissue-type plasminogen activator (P=0.01). Lower K_s (P=0.04) and tendency towards longer CLT (P=0.10) were observed in patients with a left atrium diameter>40mm. Patients with a CHA₂DS₂-VASc score of 3 or more (82.5%) were characterized by higher thrombin-activatable fibrinolysis inhibitor antigen (P=0.009). K_s was inversely correlated with log NT-proBNP (r=-0.34, P<0.0001), plasminogen activator inhibitor-1 (PAI-1) antigen (r=-0.24, P=0.002) and C-reactive protein (r=-0.18, P=0.02), while CLT was positively correlated with log NT-proBNP (R=0.61, P<0.0001) and ETP (r=0.37, P<0.0001), which were interrelated (r=0.59, P<0.0001). After adjustment for potential confounders, PAI-1 (odds ratio [OR]: 1.14; 95% confidence interval [CI]: 1.02-1.26) was the only independent predictor of low K_s (the lowest quartile,≤6×10^-9cm²), while NT-proBNP (OR: 1.21; 95% CI: 1.12-1.31) and PAI-1 (OR: 1.30; 95% CI: 1.12-1.51) both predicted prolonged CLT (the top quartile,≥109min).

CONCLUSION

In AF patients prothrombotic fibrin clot properties assessed ex vivo are determined by PAI-1 and NT-proBNP and this phenotype is associated with prior ischemic stroke.

Plasma fibrin D-dimer and the risk of left atrial thrombus: A systematic review and meta-analysis

Background

Plasma fibrin d-dimer has been taken as a marker for thrombus. The aim of this study was to evaluate the relationship between d-dimer (DD) levels and left atrial spontaneous echo contrast (SEC)/left atrial thrombus (LAT).

Methods

We identified clinical studies by systematic search of MEDLINE and EMBASE databases up to Feb 2016. All observational studies that considered DD as a study factor and trans-esophageal echocardiography (TEE) identified SEC/LAT as an outcome were included. Two reviewers independently selected the studies and extracted the data.

Results

Of the 21 included studies, 16 studies (2652 patients) have compared the mean DD differences between patients with and without an evidence of the presence of SEC/LAT, 9 studies (1667 patients) have estimated the diagnostic value of DD in the presence of LAT, and 11 studies (1856 patients) have available information to calculate a ratio of the presence of LAT among individuals in the top and the bottom third of DD levels. The pooled standardized mean difference (SMD) of DD between patients with and without left atrial SEC and/or LAT was 1.29 [95%CI: 0.51, 2.08], with SMDs of 0.42 [95% CI: 0.08, 0.77] and 2.34 [95% CI: 1.01, 3.68] in SEC/LAT and LAT subgroups, respectively. The combined risk ratio of the presence of LAT among individuals between the top of the distribution of DD levels and that in the bottom third was 3.84 [95% CI: 2.35, 6.28], associating with a mean difference of 0.78 ug/ml (1.10 vs 0.32 ug/ml). The pooled sensitivity, specificity and positive likelihood ratio of DD for LAT were 0.75 [95% CI: 0.65, 0.83], 0.81 [95% CI: 0.59, 0.93] and 4.0 [95% CI: 1.7, 9.9], respectively.

Conclusions

High plasma fibrin DD was associated with left atrial SEC/LAT, particularly among patients with LAT. DD levels have moderate sensitivity and specificity for diagnosing LAT.

Blood markers of inflammation and endothelial dysfunction in cardioembolic stroke: systematic review and meta-analysis

CONTEXT

Various processes including inflammation and endothelial dysfunction have been implicated in the pathogenesis of cardioembolic (CE) strokes.

OBJECTIVE

To review the evidence and investigate the association between immune-inflammatory biomarkers and CE strokes versus other stroke subtypes.

METHODS

We systematically reviewed the literature (sources: MEDLINE, web-based register http://stroke-biomarkers.com , reference lists) with quality assessment and meta-analysis of selected articles.

RESULTS

The most consistent association was found between C-reactive protein (CRP) and CE strokes when compared to other stroke subtypes (standardized mean difference 0.223 (0.116, 0.343); p < 0.001) Conclusions: Our findings confirm a possible association between selected inflammatory biomarkers and CE stroke.

Impact of statin therapy on plasma levels of plasminogen activator inhibitor-1. A systematic review and meta-analysis of randomised controlled trials

Elevated plasma levels of the pro-thrombotic and pro-inflammatory factor plasminogen activator inhibitor-1 (PAI-1) may contribute to the pathogenesis of atherosclerotic cardiovascular disease. Beyond their lipid-lowering effect, statins have been shown to modulate plasma PAI-1 levels but evidence from individual randomised controlled trials (RCTs) is controversial. Therefore, we aimed to assess the potential effects of statin therapy on plasma PAI-1 concentration through a meta-analysis of RCTs. We searched Medline and SCOPUS databases (up to October 3, 2014) to identify RCTs investigating the effect of statin therapy on plasma PAI-1 concentrations. We performed random-effects meta-analysis and assessed heterogeneity (I² test, subgroup and sensitivity analyses) and publication bias (funnel plot, Egger and "trim and fill" tests). Sixteen RCTs (comprising 19 treatment arms) were included and pooled analyses showed a significant effect of statins in reducing plasma PAI-1 concentrations (weighted mean difference WMD: -15.72 ng/ml, 95 % confidence interval [CI]: -25.01, -6.43,). In subgroup analysis, this effect remained significant in with lipophilic statins (atorvastatin and simvastatin) (WMD: -21.32 ng/ml, 95 % CI: -32.73, -9.91, I²=99 %) and particularly atorvastatin (WMD: -20.88 ng/mL, 95 % CI: -28.79, -12.97, I2=97 %). In the meta-regression analysis, the impact of statins on PAI-1 did not correlate with the administered dose, duration of treatment and changes in plasma LDL-cholesterol concentrations. Finally, evidence of publication bias was observed. In conclusion, taking into account the limit of heterogeneity between studies, the present meta-analysis suggests that statin therapy (mainly atorvastatin) significantly lowers plasma PAI-1 concentrations.

The current role and future prospects of D-dimer biomarker

D-dimers have been discovered as by-products of fibrinolysis. In situations where the fundamental pathology is associated with increased thrombolytic activity, D-dimer assays could serve an integral role in the clinical workup, and have an already established role in the diagnosis of clinical disorders of venous thromboembolism, and disseminated intravascular coagulation. However, there is growing literature suggesting that this is not the only clinical scenario where D-dimers may be of significance. They may also become an important biomarker in coronary and carotid artery atherosclerosis and aortic diseases. Being a non-invasive and quick means of diagnosis, D-dimers are a cost-effective tool used for diagnosing diseases. With the future being steered in the direction of preventive cardiology, it is imperative for clinicians to understand how to effectively utilize biomarkers in order to diagnose disorders. In this context, we review D-dimer's origin, current clinical utility, and potential future applications.