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

Reprint of: Scientific statement from the French neurovascular and cardiac societies for improved detection of atrial fibrillation after ischaemic stroke and transient ischaemic attack

Atrial fibrillation (AF) is the primary cause of ischaemic stroke and transient ischaemic attack (TIA). AF is associated with a high risk of recurrence, which can be reduced using optimal prevention strategies, mainly anticoagulant therapy. The availability of effective prophylaxis justifies the need for a significant, coordinated and thorough transdisciplinary effort to screen for AF associated with stroke. A recent French national survey, initiated and supported by the Société française neurovasculaire (SFNV) and the Société française de cardiologie (SFC), revealed many shortcomings, such as the absence or inadequacy of telemetry equipment in more than half of stroke units, insufficient and highly variable access to monitoring tools, delays in performing screening tests, heterogeneous access to advanced or connected ambulatory monitoring techniques, and a lack of dedicated human resources. The present scientific document has been prepared on the initiative of the SFNV and the SFC with the aim of helping to address the current shortcomings and gaps, to promote efficient and cost-effective AF detection, and to improve and, where possible, homogenize the quality of practice in AF screening among stroke units and outpatient post-stroke care networks. The working group, composed of cardiologists and vascular neurologists who are experts in the field and are nominated by their peers, reviewed the literature to propose statements, which were discussed in successive cycles, and maintained, either by consensus or by vote, as appropriate. The text was then submitted to the SFNV and SFC board members for review. This scientific statement document argues for the widespread development of patient pathways to enable the most efficient AF screening after stroke. This assessment should be carried out by a multidisciplinary team, including expert cardiologists and vascular neurologists.

Scientific statement from the French neurovascular and cardiac societies for improved detection of atrial fibrillation after ischaemic stroke and transient ischaemic attack

Atrial fibrillation (AF) is the primary cause of ischaemic stroke and transient ischaemic attack (TIA). AF is associated with a high risk of recurrence, which can be reduced using optimal prevention strategies, mainly anticoagulant therapy. The availability of effective prophylaxis justifies the need for a significant, coordinated and thorough transdisciplinary effort to screen for AF associated with stroke. A recent French national survey, initiated and supported by the Société française neurovasculaire (SFNV) and the Société française de cardiologie (SFC), revealed many shortcomings, such as the absence or inadequacy of telemetry equipment in more than half of stroke units, insufficient and highly variable access to monitoring tools, delays in performing screening tests, heterogeneous access to advanced or connected ambulatory monitoring techniques, and a lack of dedicated human resources. The present scientific document has been prepared on the initiative of the SFNV and the SFC with the aim of helping to address the current shortcomings and gaps, to promote efficient and cost-effective AF detection, and to improve and, where possible, homogenize the quality of practice in AF screening among stroke units and outpatient post-stroke care networks. The working group, composed of cardiologists and vascular neurologists who are experts in the field and are nominated by their peers, reviewed the literature to propose statements, which were discussed in successive cycles, and maintained, either by consensus or by vote, as appropriate. The text was then submitted to the SFNV and SFC board members for review. This scientific statement document argues for the widespread development of patient pathways to enable the most efficient AF screening after stroke. This assessment should be carried out by a multidisciplinary team, including expert cardiologists and vascular neurologists.

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

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

High brain natriuretic peptide level is associated with severe stroke in patients taking oral anticoagulants: A sub-analysis of the PASTA registry study

BACKGROUND

Brain natriuretic peptides (BNP) are an important diagnostic and prognostic marker in patients with heart failure. However, the relationship between BNP levels and stroke severity in patients with atrial fibrillation (AF) remains unelucidated. In this study, we aimed to investigate the association between stroke severity at admission and BNP levels.

METHODS

In this prospective observational study, we used data from 513 patients with AF and acute ischemic stroke treated with oral anticoagulants (OAC) registered in the Multicenter Prospective Analysis of Stroke Patients Taking Oral Anticoagulants study. The patients were divided into two groups: high-BNP (≥200 pg/mL) and low-BNP level (<200 pg/mL) groups. We compared the clinical characteristics between the two groups and determined the effect of BNP levels on stroke severity on admission.

RESULTS

Among the 513 enrolled patients, 248 (females, n = 30; median age, 82 years) and 265 (females, n = 76; median age, 71 years) were assigned to the high- and low-BNP level groups, respectively. The high-BNP level group had a higher proportion of patients with severe stroke (National Institutes of Health Stroke Scale score, ≥10) on admission (49.2% vs. 32.8%, p = 0.002) and major vessel occlusion (57.5% vs. 39.2%, p < 0.0001) than that had by the low-BNP level group. Multivariate analysis showed that high BNP level was independently associated with severe stroke on admission (odds ratio 1.07, 95% confidence interval 1.00-1.15; p = 0.0478).

CONCLUSIONS

High BNP level compared with low BNP level was associated with severe stroke and major vessel occlusion, even before OAC treatment.

Prognostic Impact of Atrial Fibrillation Pattern and other Clinical Biomarkers in Patients with Stroke Admitted in a Tertiary Hospital in Cebu City from 2015-2022

Background

The effect of atrial fibrillation (AF) patterns and clinical biomarkers among patients with AF-related stroke is still controversial.

Objectives

The objective of this study is to determine the association of the pattern of AF and markers on routine blood tests with the outcome of patients after an AF-related stroke.

Methods

This is a retrospective cohort study of patients with stroke and AF admitted in a tertiary hospital in Cebu City from 2015-2022. Patients' baseline characteristics, laboratory tests, ECG, and radiologic data were collected. Descriptive statistics such as mean and frequency were computed. The Kaplan-Meier method and the log-rank test were used to calculate the incidence time. The Cox regression analysis was used to determine factors associated with survival. A stepwise regression technique was used in model building.

Results

The mortality rate of patients with AF-related stroke was 0.02. A Kaplan Meier survival estimate shows that patients with paroxysmal AF have better survival. Upon model building of variables, age, red cell distribution width (RDW), neutrophil-to-lymphocyte ratio (NLR), platelet count, low density lipid cholesterol (LDL-C), and pattern of AF were predictive of mortality in patients with AF-related stroke.

Conclusions

Among AF-related stroke patients admitted at a tertiary hospital in Cebu City, pattern of AF, age, RDW, NLR, platelet count, and LDL-C were associated with mortality. The parameters associated with increased mortality could be easily assessed using an ECG, CBC, and lipid profile. These are all readily available and cost-efficient.

Atherothrombotic and thrombolytic biomarkers in incident stroke and atrial fibrillation-related stroke: The Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND AND AIMS

Although several biomarkers have been studied in thromboembolic stroke, measuring the balance between thrombus formation and thrombolysis and data on its role in predicting stroke and atrial fibrillation (AF)-related stroke is limited. We sought to assess atherothrombotic biomarkers grouped into composite factors that reflect thrombotic and thrombolytic potential, and the balance between these factors as it relates to incident stroke or transient ischemic attack (TIA) and stroke/TIA in AF.

METHODS

A Thrombotic Factor, derived from fibrinogen, plasmin-antiplasmin complex, factor VIII, D-dimer, and lipoprotein(a); and a Thrombolytic Factor, derived from plasminogen and oxidized phospholipids on plasminogen, were evaluated at baseline in 5,764 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We evaluated the association between these two factors representative of thrombotic and thrombolytic potential and incident stroke/TIA (n = 402), and AF-related stroke/TIA (n = 82) over a median of 13.9 and 3.7 years, respectively. Cox proportional hazard models adjusted for medication use, cardiovascular risk factors and CHA2DS2-VASc score were utilized. Harrell's C-index was estimated to evaluate model performance.

RESULTS

In models including both factors, Thrombotic Factor was positively while Thrombolytic Factor was inversely associated with incident stroke/TIA and AF-related stroke/TIA. Incorporating these factors along with the CHA2DS2-VASc in adjusted models resulted in a small improvement in risk prediction of incident stroke/TIA and AF-related stroke/TIA compared to models without the factors (C-index from 0.697 to 0.704, and from 0.657 to 0.675, respectively).

CONCLUSIONS

Composite biomarker factors, representative of the balance between thrombotic and thrombolytic propensity, provided an improvement in predicting stroke/TIA beyond CHA2DS2-VASc score.

Country and health expenditure are major predictors of withholding anticoagulation in atrial fibrillation patients at high risk of stroke

BACKGROUND

Guidelines for patients with atrial fibrillation (AF) at high thromboembolic risk recommend oral anticoagulants (OACs) for preventing stroke and systemic embolism (SE). The reasons for guideline non-adherence are still unclear.

AIM

The aim is to identify clinical, demographic and non-patient characteristics associated with withholding OAC in patients with AF at high stroke risk.

METHODS

Patients in the Global Anticoagulant Registry in the FIELD-AF, newly diagnosed with AF between March 2010 and August 2016, and with CHA2DS2-VASc Score≥2 (excluding sex), were grouped by OAC treatment at enrolment. Factors associated with OAC non-use were analysed by multivariable logistic regression.

RESULTS

Of 40 416 eligible patients, 12 126 (30.0%) did not receive OACs at baseline. Globally, OAC prescription increased over time, from 60.4% in 2010-2011 to 74.7% in 2015-2016. Country of enrolment was the major predictor for OAC withholding (χ2-df=2576). Clinical predictors of OAC non-use included type of AF (χ2-df=404), history of bleeding (χ2-df=263) and vascular disease (χ2-df=99). OACs were used most frequently around the age of 75 years and decreasingly with younger as well as older age beyond 75 years (χ2-df=148). Non-cardiologists (χ2-df=201) and emergency room physicians (χ2-df=14) were less likely to prescribe OACs. OAC prescription correlated positively with country health expenditure.

CONCLUSIONS

Approximately one out of three AF patients did not receive OAC, while eligible according to the guidelines. Country of enrolment was the major determinant of anticoagulation strategy, while higher country health expenditure was associated with lower likelihood of withholding anticoagulation.

Serum NT-proBNP level for predicting functional outcomes after acute ischemic stroke

N-terminus pro-brain natriuretic peptide (NT-proBNP) has been studied and recognized as a biomarker of cardiac thrombogenicity and stroke risk. However, the association between NT-proBNP and functional outcomes following acute ischemic stroke is still debated. This study aimed to investigate whether serum NT-proBNP level is associated with functional outcomes in acute ischemic stroke individuals. This prospective cohort study included patients diagnosed with acute ischemic stroke, and serum NT-proBNP levels were measured within 72 h. At 3 months, all patients were followed up for a modified Rankin Scale (mRS), and logistic regression models were used to evaluate the association of NT-proBNP on the primary outcome, in which a score of 3-6 was classified as an unfavorable functional outcome. Sixty-seven patients were enrolled in the study, and 23 (34.3%) patients were identified with an unfavorable functional outcome. Elevated serum NT-proBNP levels (> 100 pg/mL) were observed in 57 (85.1%) patients, and the Youden index demonstrated a cutpoint estimation of poor outcomes at 476 pg/mL with 74% sensitivity and 63% specificity. Multivariate regression analysis showed an elevation of NT-proBNP above the cutpoint level was an independent predictor for unfavorable functional outcomes, odds ratio 3.77, 95% confidence interval (1.04-13.62), P = 0.04. The present study demonstrated that elevated serum NT-proBNP levels were expected among acute ischemic stroke patients and represented the risk of unfavorable functional outcomes, suggesting that NT-proBNP might be a useful biomarker for predicting prognosis after ischemic stroke.

Atrial Fibrillation Detected by Implantable Monitor in Embolic Stroke of Undetermined Source: A New Clinical Entity

Background: High incidence of covert paroxysmal atrial fibrillation (CPAF) detected by an implantable cardiac monitor (ICM) is expected in embolic stroke of undetermined source (ESUS) patients. This study aimed to determine the CPAF rate in an ESUS cohort using ICMs and compare stroke characteristics of patients with CPAF to those with known or inpatient-diagnosed AF (KIDAF). Methods: ESUS patients with ICMs were enrolled. ESUS diagnosis was defined as a non-lacunar stroke in the absence of symptomatic atherosclerotic stenosis (≥50%), no major-risk cardioembolic source, and no other specific cause. ESUS characteristics of patients with CPAF were compared to ESUS patients without CPAF and to KIDAF stroke patients. Results: During the median follow-up of 476 (371–615) days, CPAF was newly detected in 38/163 (23.31%) patients within 236 (115.50–510.75) days after the stroke. CPAF was independently associated to older age, coronaropathy, left atrial dilation, and atrial hyperexcitability, but not to stroke severity. Compared to KIDAF strokes, ESUS with CPAF had lower rates of proximal occlusion leading to milder clinical severity (NIHSS: 3.00 (1.00–8.25) vs. 14.50 (6.00–21.00)). Conclusions: Our study revealed a high proportion of CPAF in ESUS. We highlight that CPAF is a distinct clinical entity compared to KIDAF based on differences in stroke characteristics and AF diagnosis temporality.

Role of New Potential Biomarkers in the Risk of Thromboembolism in Atrial Fibrillation

Ischemic stroke risk in atrial fibrillation differs from patient to patient, depending on numerous variables. Many attempts have been made to translate this difference into simple numbers and to compare it to the hemorrhagic risk of anticoagulation. Different clinical scores have been studied to define a clear strategy. One score, the CHA₂DS₂-VASc score, has been extensively and successfully applied worldwide. Nevertheless, it is not yet the “perfect instrument”. Many proposals have been made to integrate its clinical parameters with some biomarkers to improve its predictive power. This short review describes some of these biomarkers and their possible implications in potentiating the efficacy of clinical scores.