Association of stroke risk biomarkers with stroke symptoms: the Reasons for Geographic and Racial Differences in Stroke cohort

Diagnostic performance of plasma D-dimer, fibrinogen, and D-dimer to fibrinogen ratio as potential biomarkers to predict hypertension-associated acute ischemic stroke

Background

Ischemic stroke is a common type of stroke that leads to death and functional disability in hypertensive patients. However, there are no well-studied non-invasive and less expensive fluid biomarkers routinely used to detect ischemic stroke in hypertensive patients. Hence, this study aimed to tease out the performance of D-dimer, fibrinogen, and the D-dimer to fibrinogen ratio (DDFR) in predicting hypertension-associated acute ischemic stroke.

Methods

A hospital-based cross-sectional study was done from October 2022 to January 2022 at Yikatit 12 Hospital Medical College, Ethiopia. We recruited 55 hypertensive patients who had an ischemic stroke and 110 who did not. A ROC curve was used to calculate the areas under the curves (AUCs) and determine the diagnostic power of the D-dimer, fibrinogen, and DDFR. The Youden index was used to find the best cut-off points for biomarkers in detecting acute ischemic stroke. A De Long test was employed to show whether there was a significant difference between the AUCs of biomarkers in diagnosing ischemic stroke.

Results

D-dimer yielded the highest diagnostic power (AUC = 0.776) in detecting acute ischemic stroke, followed by DDFR (AUC = 0.763) and fibrinogen (AUC = 0.694), but there was no significant difference between them. At 0.52 μg/ml cut-off point, D-dimer had 82.9% sensitivity, 66.7% specificity, 62.5% PPV, and 85.3% NPV to diagnose acute ischemic stroke. Fibrinogen could detect acute ischemic stroke at 405.85 mg/dl level, with 70.0% sensitivity, 57.1% specificity, 41.2% PPV and 81.6% NPV. At a 1.83 ratio, DDFR might also identify ischemic stroke with 80.0% sensitivity, 67.1% specificity, 51.1% PPV, and 88.7% NPV.

Conclusion

We showed D-dimer, fibrinogen, and DDFR as promising, affordable, and non-invasive biomarkers for the detection of ischemic stroke among subjects with hypertension. This will help clinicians make an early diagnosis and better guide patient therapy.

Comparison of circulating lipid profiles, D-dimer and fibrinogen levels between hypertensive patients with and without stroke

BACKGROUND

Stroke is one of the leading causes of global mortality and disability, particularly in hypertensive patients. This study aimed to compare lipid profile, fibrinogen, and D-dimer levels between hypertensive patient with and without stroke.

METHODS

This was a facility-based cross-sectional study conducted from November 2022 to January 2023 among 115 hypertensive patients (70 patients without stroke and 45 with stroke) who had follow-up at Yikatit 12 Hospital Medical College, Ethiopia. All data analyses were done using SPSS version 25.0 and comparisons of variables between groups were made using the Chi-square test, independent sample t-test, and Mann-Whitney U test. Multiple logistic regression analysis was done to identify predictors of stroke among hypertensive patients. A p-value <0.05 was assumed to be statistically significant for all statistical tests.

RESULTS

Significantly elevated levels of TC, LDL-C, D-DI, and fibrinogen were observed in the stroke group than in the non-stroke group (p-value<0.05). The mean values of TC, D-DI, and fibrinogen were significantly higher in patients with ischemic stroke compared to those with hemorrhagic stroke. Duration of hypertension (AOR: 1.21; CI: 1.10, 2.09), TC (AOR:1.07; CI: 1.01, 1.22), D-DI (AOR: 1.15; CI: 1.05, 1.69) and fibrinogen (AOR:1.19; CI: 1.10, 2.89) were identified to be independent predictors of stroke in hypertensive patients.

CONCLUSION

The circulating levels of TC, LDL-C, D-DI and fibrinogen in hypertensive patients with stroke were significantly higher than in those without stroke. But only TC, D-DI, and fibrinogen were found to be predictors of stroke in hypertensives. Considerably higher TC, D-DI, and fibrinogen levels were also seen in patients with ischemic stroke than in those with hemorrhagic stroke. This confirms the key roles of dyslipidemia (hypercholesterolemia) and aberrant hemostatic activation to stroke development, notably ischemic stroke.

Biomarkers as MEDiators of racial disparities in risk factors (BioMedioR): Rationale, study design, and statistical considerations

PURPOSE

Relative to White adults, Black adults have a substantially higher prevalence of hypertension and diabetes, both key risk factors for stroke, cardiovascular disease, cognitive impairment, and dementia. Blood biomarkers have shown promise in identifying contributors to racial disparities in many chronic diseases.

METHODS

We outline the study design and related statistical considerations for a nested cohort study, the Biomarker Mediators of Racial Disparities in Risk Factors (BioMedioR) study, within the 30,239-person biracial REasons for Geographic And Racial Differences in Stroke (REGARDS) study (2003-present). Selected biomarkers will be assessed for contributions to racial disparities in risk factor development over median 9.4 years of follow-up, with initial focus on hypertension, and diabetes. Here we outline study design decisions and statistical considerations for the sampling of 4,400 BioMedioR participants.

RESULTS

The population for biomarker assessment was selected using a random sample study design balanced across race and sex to provide the optimal opportunity to describe association of biomarkers with the development of hypertension and diabetes. Descriptive characteristics of the BioMedioR sample and analytic plans are provided for this nested cohort study.

CONCLUSIONS

This nested biomarker study will examine pathways with the target to help explain racial differences in hypertension and diabetes incidence.

Atrial Fibrillation and Stroke Symptoms in the REGARDS Study

Background

It is unknown if stroke symptoms in the absence of a stroke diagnosis are a sign of subtle cardioembolic phenomena. The objective of this study was to examine associations between atrial fibrillation (AF) and stroke symptoms among adults with no clinical history of stroke or transient ischemic attack (TIA).

Methods and Results

We evaluated associations between AF and self‐reported stroke symptoms in the national, prospective REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort. We conducted cross‐sectional (n=27 135) and longitudinal (n=21 932) analyses over 8 years of follow‐up of REGARDS participants without stroke/transient ischemic attack and stratified by anticoagulant or antiplatelet agent use. The mean age was 64.4 (SD±9.4) years, 55.3% were women, and 40.8% were Black participants; 28.6% of participants with AF reported stroke symptoms. In the cross‐sectional analysis, comparing participants with and without AF, the risk of stroke symptoms was elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (odds ratio [OR], 2.22; 95% CI, 1.89–2.59) or antiplatelet agents only (OR, 1.92; 95% CI, 1.61–2.29) but not for adults with AF taking anticoagulants (OR, 1.08; 95% CI, 0.71–1.65). In the longitudinal analysis, the risk of stroke symptoms was also elevated for adults with AF taking neither anticoagulants nor antiplatelet agents (hazard ratio [HR], 1.41; 95% CI, 1.21–1.66) or antiplatelet agents only (HR, 1.23; 95% CI, 1.04–1.46) but not for adults with AF taking anticoagulants (HR, 0.86; 95% CI, 0.62–1.18).

Conclusions

Stroke symptoms in the absence of a stroke diagnosis may represent subclinical cardioembolic phenomena or “whispering strokes.” Future studies examining the benefit of stroke symptom screening may be warranted.

Semiparametric isotonic regression analysis for risk assessment under nested case-control and case-cohort designs

Two-phase sampling designs, including nested case-control and case-cohort designs, are frequently utilized in large cohort studies involving expensive biomarkers. To analyze data from two-phase designs with a binary outcome, parametric models such as logistic regression are often adopted. However, when the model assumptions are not valid, parametric models may lead to biased estimation and risk evaluation. In this paper, we propose a robust semiparametric regression model for binary outcomes and an easy-to-implement computational procedure that combines the pool-adjacent violators algorithm with inverse probability weighting. The asymptotic properties are established, including consistency and the convergence rate. Simulation studies show that the proposed method performs well and is more robust than logistic regression methods. We demonstrate the application of the proposed method to real data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.

N-Terminal pro-B-type natriuretic peptide and stroke risk across a spectrum of cerebrovascular disease: The REasons for Geographic and Racial Differences in Stroke cohort

BACKGROUND

N-terminal pro-B-type natriuretic peptide (NT-proBNP), a commonly used clinical marker of cardiac function, is associated with the presence of stroke symptoms and is a strong risk factor for future atrial fibrillation, stroke, and all-cause mortality. Few data are available on the association between NT-proBNP levels and stroke recurrence.

OBJECTIVE

We studied the relationship between NT-proBNP and risk of future ischemic stroke across the continuum of preexisting cerebrovascular conditions: asymptomatic, prior stroke symptoms, prior transient ischemic attack (TIA), and prior stroke.

METHODS

The Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort enrolled 30,239 black and white Americans aged 45 years and older from 2003 to 2007. With 5.4 years follow-up, baseline NT-proBNP was measured in 892 participants who developed ischemic stroke and a 4328-person cohort random sample. Hazard ratios of stroke by baseline NT-proBNP were calculated in groups based on the presence of prebaseline cerebrovascular conditions.

RESULTS

In the fully adjusted model, elevated NT-proBNP was associated with stroke risk in participants without a preexisting cerebrovascular condition (hazard ratio [HR], 2.32; 95% confidence interval [CI], 1.84-2.94) and in participants with a history of stroke symptoms (HR, 1.67; 95% CI, 1.01-2.78) or transient ischemic attack (HR, 2.66; 95% CI, 1.00-7.04) but not among those with prior stroke (HR, 1.26; 95% CI, 0.71-2.21).

CONCLUSIONS

These findings support the potential for NT-proBNP testing to identify people who are at highest risk for future stroke.

Elevated Hs-CRP Levels Are Associated with Higher Risk of Intracranial Arterial Stenosis

Correlation between the level of high-sensitivity C-reactive protein (hs-CRP) and the incidence of intracranial arterial stenosis (ICAS) is unclear. We aim to investigate the relationship between hs-CRP levels and ICAS. A total of 1458 patients aged ≥ 40 years were enrolled in this study. All the participants had a magnetic resonance angiography (MRA) examination for the evaluation of ICAS. Participants were classified into four groups according to stroke and ICAS. Multivariable logistic regression models were used to assess the relationship of hs-CRP levels and ICAS status. A total of 432 (29.63%) subjects had ICAS. The levels of hs-CRP in stroke group were significantly higher than those in non-stroke group (p < 0.001). Patients with ICAS tend to have higher hs-CRP levels (p < 0.001). In multivariate analysis, the fourth hs-CRP quartile had the strongest association with ICAS in both stroke group and non-stroke group (OR 2.512, 95% CI 1.651-3.853, p < 0.001 for stroke group, and OR 2.534, 95% CI 1.435-4.595, p = 0.002 for non-stroke group) among the four quartiles of hs-CRP levels. Our study suggests that elevated serum hs-CRP levels are associated with higher risk of ICAS, in both stroke patients and non-stroke participants.

Elevated level of D-dimer increases the risk of stroke

The aim of this study was to systematically evaluate the association between D-dimer level and the risk of stroke through performing a meta-analysis. PubMed, Web of Science, EMBASE and Cochrane Library were searched for potentially eligible literature. Prospective observational studies or case-control studies were included. The study characteristics and relevant data were extracted. Hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were pooled to estimate the association between D-dimer level and the risk of stroke. Seven prospective studies with 22,207 patients and three case-control studies with 2,248 patients were included. For the prospective studies, the pooled HRs of higher D-dimer level for all types of stroke, ischemic stroke and hemorrhagic stroke were 1.55 (95% CI, 1.28- 1.87), 1.62 (95% CI, 1.18-2.22) and 1.30 (95% CI, 0.63-2.68), respectively. The pooled HRs per SD increase in log D-dimer for all types of stroke, ischemic stroke and hemorrhagic stroke were 1.16 (95% CI, 1.06-1.26), 1.11 (95% CI, 1.03-1.21) and 1.11 (95% CI, 0.95-1.30), respectively. For the case-control studies, the pooled OR of higher D-dimer level for acute ischemic stroke was 2.06 (95% CI, 1.08-3.96). No significant publication bias was found in the meta-analysis. In conclusion, our results suggested that higher D-dimer level was associated with higher risk of stroke, especially ischemic stroke.