Serial Measurements of N-Terminal pro-Brain Natriuretic Peptide after Acute Ischemic Stroke

Elevation of cardiac biomarkers in stroke is associated with pathological findings on cardiac MRI-results of the HEart and BRain interfaces in Acute Stroke study

INTRODUCTION

Cardiac biomarkers, such as high-sensitivity cardiac troponin T (hs-cTnT), are frequently elevated in ischemic stroke patients but the mechanisms underlying this elevation are insufficiently understood. We determined the presence of cardiac damage, assessed using cardiac magnetic resonance imaging (CMR), in stroke patients with elevated hs-cTnT and brain natriuretic peptide (BNP).

METHODS

This is a post hoc analysis of the prospective, investigator-initiated, cross-sectional HEart and BRain interfaces in Acute Stroke (HEBRAS) study. All patients underwent the measurement of hs-cTnT and BNP as well as gadolinium-enhanced CMR in the acute phase of ischemic stroke. We performed unadjusted and adjusted logistic regression models to assess the association between hs-cTnT and BNP elevation and the presence of pathological CMR findings.

RESULTS

Two hundred and thirty-three stroke patients (median age 67 years, 33% female) were included, of whom 43 (21%) had elevated hs-cTnT and 109 (47%) had elevated BNP. Hundred of the 233 (43%) patients had pathological findings on CMR had focal fibrosis as detected by late-gadolinium enhancement (LGE) in 51 (23%), left-ventricular hypertrophy (LVH) in 38 (16%), reduced LVEF in 32 (14%), and left-atrial dilatation in 34 (15%). After adjustment for potential confounders, both hs-cTnT (adjOR 5.0 (95%CI 2.1-11.7), p < 0.001) and BNP (adjOR 4.1 (95%CI 2.3-7.3), p < 0.001) were significantly associated with pathological findings on CMR. Hs-cTnT was associated with LGE, LVEF, and LVH, whereas BNP was associated with left-atrial dilatation and LVEF, LVH.

CONCLUSION

Elevated cardiac biomarkers in acute stroke including CMR are strongly associated with pathological findings on CMR. In acute stroke patients, the elevation of cardiac biomarkers may identify patients who require a more thorough cardiology work-up.

Biomarkers Predictive of Long-Term Outcome After Ischemic Stroke: A Meta-Analysis

BACKGROUND AND PURPOSE

The goal of this study was to systematically review the utility of serum biomarkers in the setting of ischemic stroke (IS) to predict long-term outcome.

METHODS

A systematic literature review was performed using the PubMed and MEDLINE databases for studies published between 1986-2018. All studies assessing long-term functional outcome (defined as 30 days or greater) following IS with respect to serum biomarkers were included. Data were extracted and pooled using a meta-analysis of odds ratios.

RESULTS

Of the total 2928 articles in the original literature search, 183 studies were ultimately selected. A total of 127 serum biomarkers were included. Biomarkers were grouped into several categories: inflammatory (32), peptide/enzymatic (30), oxidative/metabolic (28), hormone/steroid based (23), and hematologic/vascular (14). The most commonly studied biomarkers in each category were found to be CRP, S100β, albumin, copeptin, and D-dimer. With the exception of S100β, all were found to be statistically associated with >30-day outcome after ischemic stroke.

CONCLUSIONS

Serum-based biomarkers have the potential to predict functional outcome in IS patients. This meta-analysis has identified CRP, albumin, copeptin, and D-dimer to be significantly associated with long-term outcome after IS. These biomarkers have the potential to serve as a platform for prognosticating stroke outcomes after 30 days. These serum biomarkers, some of which are routinely ordered, can be combined with imaging biomarkers and used in artificial intelligence algorithms to provide refined predictive outcomes after injury. Ultimately these tools will assist physicians in providing guidance to families with regards to long-term independence of patients.

Prevalence and determinants of systolic and diastolic cardiac dysfunction and heart failure in acute ischemic stroke patients: The SICFAIL study

AIMS

Ischaemic stroke (IS) might induce alterations of cardiac function. Prospective data on frequency of cardiac dysfunction and heart failure (HF) after IS are lacking. We assessed prevalence and determinants of diastolic dysfunction (DD), systolic dysfunction (SD), and HF in patients with acute IS.

METHODS AND RESULTS

The Stroke-Induced Cardiac FAILure in mice and men (SICFAIL) study is a prospective, hospital-based cohort study. Patients with IS underwent a comprehensive assessment of cardiac function in the acute phase (median 4 days after IS) including clinical examination, standardized transthoracic echocardiography by expert sonographers, and determination of blood-based biomarkers. Information on demographics, lifestyle, risk factors, symptoms suggestive of HF, and medical history was collected by a standardized personal interview. Applying current guidelines, cardiac dysfunction was classified based on echocardiographic criteria into SD (left ventricular ejection fraction < 52% in men or <54% in women) and DD (≥3 signs of DD in patients without SD). Clinically overt HF was classified into HF with reduced, mid-range, or preserved ejection fraction. Between January 2014 and February 2017, 696 IS patients were enrolled. Of them, patients with sufficient echocardiographic data on SD were included in the analyses {n = 644 patients [median age 71 years (interquartile range 60-78), 61.5% male]}. In these patients, full assessment of DD was feasible in 549 patients without SD (94%). Prevalence of cardiac dysfunction and HF was as follows: SD 9.6% [95% confidence interval (CI) 7.6-12.2%]; DD in patients without SD 23.3% (95% CI 20.0-27.0%); and clinically overt HF 5.4% (95% CI 3.9-7.5%) with subcategories of HF with preserved ejection fraction 4.35%, HF with mid-range ejection fraction 0.31%, and HF with reduced ejection fraction 0.78%. In multivariable analysis, SD and fulfilment of HF criteria were associated with history of coronary heart disease [SD: odds ratio (OR) 3.87, 95% CI 1.93-7.75, P = 0.0001; HF: OR 2.29, 95% CI 1.04-5.05, P = 0.0406] and high-sensitive troponin T at baseline (SD: OR 1.78, 95% CI 1.31-2.42, P = 0.0003; HF: OR 1.66, 95% CI 1.17-2.33, P = 0.004); DD was associated with older age (OR 1.08, 95% CI 1.05-1.11, P < 0.0001) and treated hypertension vs. no hypertension (OR 2.84, 95% CI 1.23-6.54, P = 0.0405).

CONCLUSIONS

A substantial proportion of the study population exhibited subclinical and clinical cardiac dysfunction. SICFAIL provides reliable data on prevalence and determinants of SD, DD, and clinically overt HF in patients with acute IS according to current guidelines, enabling further clarification of its aetiological and prognostic role.

Diagnostic value of N-terminal pro B-type natriuretic peptide for nonvalvular atrial fibrillation in acute ischemic stroke patients: A retrospective multicenter case-control study

BACKGROUND

The detection of Nonvalvular atrial fibrillation (NVAF) in AIS patients may be elusive and require further investigation such as electrocardiography (ECG) and Holter monitoring. The objective of this study is to evaluate the N-terminal pro B-type natriuretic peptide (NT-proBNP) diagnostic value for NVAF and the clinical outcome of AIS patients.

METHODS

We conducted a retrospective study of AIS patients in ten hospitals of the Shaanxi province. All NVAF patients and matched patients without NVAF admitted within 7 days after stroke onset were included in our study. The admission NT-proBNP receiver operating characteristic curve was drawn to determine the discriminative power of NT-proBNP in NVAF identification. Multivariate logistic regression analysis was used to examine the odds ratios (OR) of NT-proBNP for NVAF and identify the potential factors associated with the clinical outcomes in AIS patients.

RESULTS

A total of 275 NVAF cases and 275-matched controls were included in the current study. NT-proBNP was independently associated with NVAF (OR = 64.047, 95% confidence interval [CI]: 30.298-135.390, p < .001) in AIS patients. The optimal cutoff point for the NT-proBNP level to distinguish the NVAF group from the non-NVAF group was 431.0 pg/ml, with an area under curve [AUC] of 0.910 (95% CI: 0.885-0.935, p < .001). The high NT-proBNP level (OR: 3.284, 95% CI: 1.830-5.896, p < .001) was an independent indicator that was positively related to hospitalization mortality.

CONCLUSION

The rise of the serum NT-proBNP level at first admission added great contributions to the NVAF diagnosis after AIS, and was independently associated with the hospitalization mortality of AIS patients.

Prognostic Value of NT-proBNP After Ischemic Stroke: A Systematic Review and Meta-analysis of Prospective Cohort Studies

BACKGROUND

Many studies have evaluated the relationship between N-terminal pro-brain natriuretic peptide (NT-proBNP) and its prognostic value in ischemic stroke. However, a widespread consensus has not been reached. Therefore, we completed a meta-analysis to evaluate the prognostic significance of NT-proBNP for mortality and functional outcome in patients with ischemic stroke.

METHODS

We performed a systematic search and review using the PubMed and EMBASE databases to identify literature that reported a correlation between NT-proBNP and mortality and functional outcome in ischemic stroke patients.

RESULTS

Eleven studies inclusive of 10,498 patients met the inclusion criteria. Elevated plasma NT-proBNP levels were associated with increased risk of mortality in ischemic stroke patients (all-cause mortality: odds ratio [OR] = 2.43, 95% confidence interval [CI] 1.62-3.64, P < .001, I²=74.3%; cardiovascular mortality: OR = 2.01, 95% CI 1.55-2.61, P < .001, I² = 42.6%). In addition, unfavorable functional outcomes were observed in patients with higher levels of NT-proBNP (OR = 1.68, 95% CI 1.13-2.50, P = .01, I² = 90.8%) after ischemic stroke.

CONCLUSIONS

This meta-analysis demonstrates that NT-proBNP could be a predictor of mortality and functional outcome in ischemic stroke patients.

Markers of endothelial pathology to support detection of atrial fibrillation in embolic stroke of undetermined source

A relevant part of embolic strokes of undetermined source (ESUS) is assumed to be cardiogenic. As shown previously, certain biomarkers of endothelial pathology are related to atrial fibrillation (AF). In this long-term follow-up study, we aimed to investigate whether these biomarkers are associated with subsequently diagnosed AF and with atrial cardiopathy. In 98 patients who suffered ischemic stroke of known and unknown origin L-arginine, Asymmetric (ADMA) and Symmetric Dimethylarginine (SDMA) have been measured on follow-up at least one year after index stroke. Stroke-diagnostics were available for all patients, including carotid Intima-Media-Thickness (CIMT) and comprehensive echocardiography studies. CIMT was larger in AF- compared with ESUS-patients (P < 0.001), independently from CHA2DS2VASC in the regression analysis (P = 0.004). SDMA-values were stable over time (P < 0.001; r = 0.788), whereas for ADMA moderate correlation with the initial values could be found (P = 0.007; r = 0.356). According to Kaplan-Meier-analyses, AF-detection rates were associated with CIMT (P = 0.003) and SDMA (P < 0.001). SDMA correlated with left atrial volume-index within the whole collective (P = 0.003, r = 0.322) and within the ESUS-subgroup (P = 0.003; r = 0.446). These associations were independent from CHA2DS2VASC and renal function in the regression analysis (P = 0.02 and P = 0.005, respectively). In conclusion, these results highlight SDMA and CIMT as potential markers of atrial cardiopathy and AF in ESUS-patients.

The role of N-terminal pro-brain natriuretic peptide in evaluating the prognosis of patients with intracerebral hemorrhage

A prognostic biomarker that can provide a good prediction of prognosis in patients with intracerebral hemorrhage (ICH) would be beneficial in guiding the initial management decisions in the setting of ICH. N-terminal pro-brain natriuretic peptide (NT-proBNP) is a biomarker of prognosis in patients with cardiovascular disease and ischemic stroke. However, the prognostic role of NT-proBNP in patients with spontaneous ICH is still a controversial issue. This study aimed to determine the prognostic value of NT-proBNP in patients with spontaneous ICH. A total of 132 patients from 571 ICH cases in inpatient settings were enrolled in this study. Blood samples from each subject were obtained and analyzed for NT-proBNP on admission and on days 4 and 7. The first end point was functional outcome at discharge, which was dichotomized into favorable or unfavorable; the secondary end point was mortality within 6 months after ICH. Compared with the baseline levels on admission after ICH, the NT-proBNP levels increased markedly on day 4 (P < 0.05). Multivariate logistic regression analysis indicated that the NT-proBNP level on day 4, the ICH score, and the APACHE II score were independent prognostic factors of functional outcome and 6-month mortality in ICH patients. A cutoff NT-proBNP level of 999.85 pg/ml predicted an unfavorable functional outcome (with 66.1% sensitivity and 98.7% specificity) and 6-month mortality (with 93.8% sensitivity and 92.0% specificity) in ICH patients. Thus, the NT-proBNP level on day 4 was found to be a powerful prognostic predictor of functional outcome and 6-month mortality in ICH patients, which would be beneficial to guiding the initial management decisions in the setting of ICH.

Copeptin and NT-proBNP for prediction of all-cause and cardiovascular death in ischemic stroke

OBJECTIVE

To evaluate long-term mortality in patients with acute ischemic stroke (AIS) by exploring the correlation between death and plasma concentrations of copeptin and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in a cohort study.

METHODS

In a prospective, multicenter observational study of 4,215 patients with AIS, copeptin and NT-proBNP levels were measured with a standardized method when patients were admitted to hospital. The primary endpoint was all-cause mortality or cardiovascular disease (CVD) mortality within 1 year.

RESULTS

During a follow-up period, 906 patients (20.1%, 95% confidence interval [CI] 18.9-21.2) died, including 589 cases of CVD mortality (13.1%, 95% CI 12.1-14.0). With the use of a multivariate analysis, both markers were found to have prognostic value in the same model (CVD mortality: odds ratio [OR] for fourth quartile of copeptin and NT-proBNP 1.68 and 2.58, 95% CI 1.22-2.49 and 1.76-4.05, respectively; all-cause mortality: OR for fourth quartile of copeptin and NT-proBNP 1.48 and 2.47, 95% CI 1.22-2.03 and 1.68-3.95, respectively). In a receiver operating characteristics analysis of CVD mortality, the area under the curve varied from 0.80 to 0.83 (95% CI 0.79-0.87) when the index of NT-proBNP was added and increased to 0.86 (95% CI 0.83-0.90) when both markers were added.

CONCLUSIONS

Copeptin and NT-proBNP may be useful independent prognostic markers of all-cause or CVD mortality in Chinese patients with AIS.

The determination of copeptin levels helps management decisions among transient ischaemic attack patients

BACKGROUND

Most approaches to transient ischaemic attack (TIA) triage use clinical scores and vascular imaging; however, some biomarkers have been suggested to improve the prognosis of TIA patients.

METHODS

Serum levels of copeptin, adiponectin, neopterin, neuron-specific enolase, high-sensitivity C-reactive protein, IL-6, N-terminal pro-B-type natriuretic peptide, S100β, tumour necrosis factor-alpha and IL-1α as well as clinical characteristics were assessed on consecutive TIA patients during the first 24 h of the onset of symptoms.

RESULTS

Among 237 consecutive TIA patients, 12 patients (5%) had a stroke within 7 days and 15 (6%) within 90 days. Among all candidate biomarkers analysed, only copeptin was significantly increased in patients with stroke recurrence (SR) within 7 days (P = 0.026) but not within 90 days. A cut-off point of 13.8 pmol/l was established with a great predictive negative value (97.4%). Large artery atherosclerosis (LAA) [hazard ratio (HR) 12.7, 95% CI 3.2-50.1, P < 0.001] and copeptin levels ≥13.8 pmol/l (HR 3.9, 95% CI 1.01-14.4, P = 0.039) were independent predictors of SR at the 7-day follow-up. LAA was the only predictor of 90-day SR (HR 7.4, 95% CI 2.5-21.6, P < 0.001). ABCD3I was associated with 7- and 90-day SRs (P = 0.025 and P = 0.034, respectively). The association between copeptin levels and LAA had a diagnostic accuracy of 90.3%.

CONCLUSIONS

Serum copeptin could be an important prognostic biomarker to guide management decisions among TIA patients. Therefore, TIA patients with copeptin levels below 13.8 pmol/l and without LAA have an insignificant risk of 7-day SR and could be managed on an outpatient basis.

Cardio-Protection in Acute Stroke

Background:

Measures of damage limitation for acute stroke have not produced substantial benefit to reduce stroke mortality. Search continues for measures to reduce stroke mortality.

Methods:

Literature review for influence of cardiovascular factors, specifically the value of NT proBNP (a sensitive index of cardiac impairment) for stroke mortality.

Results:

Cardiovascular factors, in particular cardiac failure, adversely influence acute stroke mortality. There is evidence of cardiological abnormality in acute strokes as indicated by ECG changes and tachycardia secondary to neurohumoral changes in acute strokes. Patients with ECG abnormality, tachycardia, dysrrhythmia and elevated levels of nor-epi-nephrine in acute stroke phase have higher mortality. Recent studies reveal that Troponin (measure of cardiac injury) and NT-proBNP (measure of cardiac function impairment) are elevated in acute stroke patients, in response to the activated Renin-Angiotensin-Aldosterone-System and other neurohumoral changes, as a protective mechanism for sympathoinhibitory activity. Patients with elevated troponin have a higher mortality. Similarly elevated NT-proBNP has been reported to be associated with higher short and long-term mortality. In one study all patients who died at 4 months had NT-proBNP levels above the median, no patient with NT-proBNP below the median value died. Two studies revealed that NT-proBNP is more significant than clinical stroke severity for stroke mortality. Protection of myocardium in stroke patients may be possible by the use of drugs such as beta-blockers and the drugs acting on RAAS. Reduction of mortality in studies of candesartan (ACCESS study) and prior beta-blockers is one such example. Heart is at risk in acute strokes and protecting heart makes sense to reduce stroke mortality.

Conclusion:

Some stroke patients die due to occult cardiac damage and functional impairment in acute phase due to common risk factors. This relationship between brain and heart needs evaluation. Protection of heart with currently available or new drugs in acute strokes is worth investigating since this intervention could be applied to a large proportion of acute stroke patients over a wide time window.

N-terminal probrain natriuretic peptide levels as a predictor of functional outcomes in patients with ischemic stroke

The prognostic value of the N-amino terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) in acute ischemic stroke (AIS) is uncertain. We sought to determine whether NT-proBNP levels were associated with functional outcomes after AIS. From August 2012 to October 2013, consecutive first-ever AIS patients admitted to the Department of Emergency of the First Affiliated Hospital of Xinxiang Medical University, China, were included in this study. Plasma NT-proBNP levels were measured from admission. Outcomes were measured as 90-day modified Rankin Scale score ('good outcome'=0-2 vs. 'poor'). Multivariate logistic regression was used to assess associations between NT-proBNP levels and outcomes. Predictive performance of NT-proBNP as compared with the clinical model was assessed by comparing receiver-operating characteristic curves. During this study period, 217 consecutive patients with AIS were included and completed 90 days of follow-up. There was a strong positive correlation between the plasma level of NT-proBNP and the National Institutes of Health Stroke Scale score (r=0.415, P=0.000). Plasma levels of NT-proBNP in patients with an unfavorable outcome were significantly higher than those in patients with a favorable outcome [3432 (interquartile range, 1100-54991) vs. 978 (interquartile range, 123-1705) pg/ml; P=0.000]. In multivariate analyses, after adjusting for all other significant outcome predictors, the NT-proBNP level that remained can be seen as an independent unfavorable outcome predictor, with an adjusted odds ratios of 4.14 (95% confidence interval, 2.72-7.99; P=0.000). Our results show that plasma NT-proBNP levels were significantly elevated in patients with an unfavorable outcome and might be of clinical importance as a supplementary tool for the assessment of functional outcomes in patients with AIS.

Neuroendocrine hormones as prognostic biomarkers in the setting of acute stroke: overcoming the major hurdles

Stroke represents one of the major causes of disability and mortality worldwide and prediction of outcome represents a challenge for both clinicians and researchers. In the past years, many blood markers have been associated with stroke outcome but despite this evidence, no biomarker is routinely used in stroke management. In this review, we focus on markers of the neuroendocrine system, which represent potential candidates to be implemented in clinical practice. Moreover, we present a systematic review and literature-based meta-analysis for copeptin, a new biomarker of the hypothalamo-pituitary-adrenal axis that has shown additional predictive value over clinical information in a large prospective study. The meta-analysis of the included 7 studies, with more than 2000 patients, reinforced its association with poor outcome (pooled odds ratio: 2.474 [1.678-3.268]) and mortality (pooled OR: 2.569 [1.642-3.495]). We further review the current situation of the topic and next steps to implement these tools by clinicians.

B-type natriuretic peptides and mortality after stroke: a systematic review and meta-analysis

OBJECTIVE

To measure the association of B-type natriuretic peptide (BNP) and N-terminal fragment of BNP (NT-proBNP) with all-cause mortality after stroke, and to evaluate the additional predictive value of BNP/NT-proBNP over clinical information.

METHODS

Suitable studies for meta-analysis were found by searching MEDLINE and EMBASE databases until October 26, 2012. Weighted mean differences measured effect size; meta-regression and publication bias were assessed. Individual participant data were used to estimate effects by logistic regression and to evaluate BNP/NT-proBNP additional predictive value by area under the receiver operating characteristic curves, and integrated discrimination improvement and categorical net reclassification improvement indexes.

RESULTS

Literature-based meta-analysis included 3,498 stroke patients from 16 studies and revealed that BNP/NT-proBNP levels were 255.78 pg/mL (95% confidence interval [CI] 105.10-406.47, p = 0.001) higher in patients who died; publication bias entailed the loss of this association. Individual participant data analysis comprised 2,258 stroke patients. After normalization of the data, patients in the highest quartile had double the risk of death after adjustment for clinical variables (NIH Stroke Scale score, age, sex) (odds ratio 2.30, 95% CI 1.32-4.01 for BNP; and odds ratio 2.63, 95% CI 1.75-3.94 for NT-proBNP). Only NT-proBNP showed a slight added value to clinical prognostic variables, increasing discrimination by 0.028 points (integrated discrimination improvement index; p < 0.001) and reclassifying 8.1% of patients into correct risk mortality categories (net reclassification improvement index; p = 0.003). Neither etiology nor time from onset to death affected the association of BNP/NT-proBNP with mortality.

CONCLUSION

BNPs are associated with poststroke mortality independent of NIH Stroke Scale score, age, and sex. However, their translation to clinical practice seems difficult because BNP/NT-proBNP add only minor predictive value to clinical information.

Time course of NT-proBNP levels after acute ischemic stroke

BACKGROUND

Studies suggest that N-terminal-pro-brain natriuretic peptide (NT-proBNP) can be a biomarker of cardioembolic stroke. However, the best time to measure it after stroke is unknown. We studied the time course of NT-proBNP in patients with ischemic stroke.

METHODS

Consecutive acute ischemic stroke patients were admitted over 10 months to a Stroke Unit. Stroke type was classified according to TOAST. Blood samples were drawn within 24, 48, and 72 hours after stroke. Friedman test was used to compare NT-proBNP values across the 3 times in all, cardioembolic and non-cardioembolic stroke patients. Post hoc analysis with Wilcoxon signed-rank tests was conducted with a Bonferroni correction. Mann-Whitney test was used to compare median values of NT-proBNP between cardioembolic and non-cardioembolic stroke patients. ROC curves were drawn to determine NT-proBNP accuracy to diagnose cardioembolic stroke at 24, 48, and 72 hours after stroke onset.

RESULTS

One hundred and one patients were included (29 cardioembolic) with a mean age of 64.5±12.3 years. NT-proBNP values for cardioembolic stroke were significantly higher (P < 0.001) than for non-cardioembolic stroke in the 3 time points. NT-proBNP was highest in the first 24-48 h after ischemic stroke and decreased significantly 72 h after stroke onset. The area under the curve for the three time points was similar.

CONCLUSION

NT-proBNP levels were highest in the first 2 days after ischemic stroke and declined significantly thereafter. However, the area under the curve for the three time points was similar. The first 72 hours after ischemic stroke have a similar diagnostic accuracy to diagnose cardioembolic stroke.

N-terminal pro-brain natriuretic peptide level determined at different times identifies transient ischaemic attack patients with atrial fibrillation

BACKGROUND AND PURPOSE

The etiological classification of patients with transient ischaemic attack (TIA) is a difficult endeavor and the use of serum biomarkers could improve the diagnostic accuracy. The aim of this study was to correlate atrial fibrillation, the main cardioembolic etiology (CE), with different serum biomarkers measured in consecutive TIA patients.

METHODS

The concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha, neuron-specific enolase, high-sensitivity C-reactive protein, IL-1-α and the N-terminal pro-B type natriuretic peptide (NT-proBNP) were quantified in the serum of 140 patients with TIA and 44 non-stroke subjects. Measurements were performed at different times throughout evolution: within 24 h of symptoms onset and at days 7 and 90.

RESULTS

With the exception of IL-6, all biomarkers were higher in TIA patients than in controls. NT-proBNP was significantly related to the presence or new diagnosis of AF at all time points analyzed. Furthermore, the baseline NT-proBNP level was significantly higher than values at the 7-day and 90-day follow-up. For this reason, different cut-off values were obtained at different times: 313 pg/ml at baseline [odds ratio (OR) = 18.99, P < 0.001], 181 pg/ml at 7 days (OR = 11.4, P = 0.001) and 174 pg/ml (OR = 8.46, P < 0.001) at 90 days.

CONCLUSION

High levels of NT-proBNP determined during the first 3 months after a TIA were associated with AF. Consequently, this biomarker may be useful to reclassify undetermined TIA patients as having disease of CE.

Amino terminal pro-B-type natriuretic peptide, secondary stroke prevention, and choice of antithrombotic therapy

BACKGROUND AND PURPOSE

Because of its association with atrial fibrillation and heart failure, we hypothesized that amino terminal pro-B-type natriuretic peptide (NT-proBNP) would identify a subgroup of patients from the Warfarin-Aspirin Recurrent Stroke Study, diagnosed with inferred noncardioembolic ischemic strokes, where anticoagulation would be more effective than antiplatelet agents in reducing risk of subsequent events.

METHODS

NT-proBNP was measured in stored serum collected at baseline from participants enrolled in Warfarin-Aspirin Recurrent Stroke Study, a previously reported randomized trial. Relative effectiveness of warfarin and aspirin in preventing recurrent ischemic stroke or death over 2 years was compared based on NT-proBNP concentrations.

RESULTS

About 95% of 1028 patients with assays had NT-proBNP below 750 pg/mL, and among them, no evidence for treatment effect modification was evident. For 49 patients with NT-proBNP >750 pg/mL, the 2-year rate of events per 100 person-years was 45.9 for the aspirin group and 16.6 for the warfarin group, whereas for 979 patients with NT-proBNP ≤750 pg/mL, rates were similar for both treatments. For those with NT-proBNP >750 pg/mL, the hazard ratio was 0.30 (95% confidence interval: 0.12-0.84; P=0.021) significantly favoring warfarin over aspirin. A formal test for interaction of NT-proBNP with treatment was significant (P=0.01).

CONCLUSIONS

For secondary stroke prevention, elevated NT-proBNP concentrations may identify a subgroup of ischemic stroke patients without known atrial fibrillation, about 5% based on the current study, who may benefit more from anticoagulants than antiplatelet agents. Clinical Trial Registration- This trial was not registered because enrollment began before 2005.

Brain natriuretic peptide is associated with worsening and mortality in acute stroke patients but adds no prognostic value to clinical predictors of outcome

BACKGROUND

At the present time, the determination of the outcome of stroke patients is based on the analysis of clinical and neuroimaging data. The use of prognostic blood biomarkers could aid in decision-making processes, e.g. admitting patients to specialized stroke units. Although the prognostic role of natriuretic peptides has been studied in heart failure and coronary diseases, the value of brain natriuretic peptide (BNP) is less known within the field of strokes.

OBJECTIVE

We aimed to study the relationship between plasma levels of BNP and acute neurological worsening or mortality after stroke in a large cohort of patients (investigating both ischemic and hemorrhagic disease).

METHODS

Consecutive stroke patients (ischemic and hemorrhagic) admitted to the Stroke Unit of our University Hospital within 24 h of the onset of symptoms were included. Stroke severity was assessed according to the National Institutes of Health Stroke Scale (NIHSS) at admission and at discharge. Neurological worsening was defined as an increase of 4 or more points in the NIHSS score or death during the patient's stay at the Stroke Unit. Blood samples were drawn upon admission to measure plasma levels of BNP (Biosite Inc., San Diego, Calif., USA). Statistical analysis was performed using SPSS 15.0 and R software.

RESULTS

Altogether, 896 patients were included in the study. BNP plasma levels were higher among patients who deteriorated the most over time (n = 112; 90.5 vs. 61.2 ng/l; p = 0.006) or died (n = 83; 118.2 vs. 60.9 ng/l; p < 0.001). Multivariate logistic regression analysis indicated that plasma BNP level was an independent predictor of neurological worsening [BNP >56.7 ng/l; odds ratio (OR) = 1.64; p = 0.04] and death after stroke (BNP >65.3 ng/l; OR = 1.97; p = 0.034). Adding BNP level to other well-known clinical predictors of bad outcome did not significantly increase the predictive value.

CONCLUSIONS

Plasma levels of BNP measured during the acute phase of stroke are associated both with early neurological worsening and mortality. However, this biological information does not supply prognostic information which would add to clinical variables, which limits its use as a biomarker. Further investigation and systematic reviews are needed to clarify the role of natriuretic peptides in stroke outcome.

The prognostic value of combined NT-pro-BNP levels and NIHSS scores in patients with acute ischemic stroke

OBJECTIVE

Determining the prognoses of patients with acute ischemic stroke is difficult. Therefore, the aim of this study was to evaluate whether the combined assessment of plasma N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and the National Institutes of Health Stroke Scale (NIHSS) variables is relevant to the prognosis of patients with acute cerebral ischemic infarction in-hospital.

METHODS

We enrolled 122 patients who were within three days of onset of acute ischemic stroke. We measured the plasma NT-pro-BNP level of each patient within 72 hours and recorded the NIHSS score on admission. The factors associated with death were investigated using a multivariate logistic regression analysis.

RESULTS

Twenty-three patients (18.85%) died during hospitalization. The frequency of atrial fibrillation (AF), the NIHSS score on admission (8.69±4.87 in the survival group vs. 14.48±2.54 in the deceased group, p<0.001) and the plasma NT-pro-BNP level (median: 926.30 pg/mL in the survival group vs. 3,280 pg/mL in the deceased group, p<0.001; Lg NT-pro-BNP 2.82±0.66 in the survival group vs. 3.46±0.52 in the deceased group, p<0.001) were each significantly higher in the deceased group than in the survival group. The optimal cut-off levels for the NT-pro-BNP level and NIHSS score to distinguish the deceased group from the survival group were 1,583.50 pg/mL and 12.5, respectively. Patients with both elevated NT-pro-BNP levels (>1,583.50 pg/mL) and NIHSS scores on admission (NIHSS >12.5) had a substantially higher mortality rate than those without elevated NT-pro-BNP levels and NIHSS scores (89.47% vs. 9.84%, p<0.001). A multivariate logistic regression analysis demonstrated that a NT-pro-BNP level >1,583.50 pg/mL (OR, 5.001; 95% CI, 1.233 to 20.287, p=0.024) and a NIHSS score >12.5 (OR, 1.465; 95% CI, 1.191 to 1.801, p<0.001) were each independent factors associated with in-hospital death.

CONCLUSION

The plasma NT-pro-BNP level and the NIHSS score added independent and incremental contributions to the prognostic stratification of patients with acute ischemic stroke.

N-Terminal Probrain Natriuretic Peptide as a Biomarker of Cardioembolic Stroke

Background and purpose

N-terminal probrain natriuretic peptide, which is mainly produced by the heart, is increased in acute stroke. We aimed to determine if N-terminal probrain natriuretic peptide could be a biomarker for ischemic stroke with a cardioembolic cause.

Methods

Consecutive sample of acute stroke patients admitted to a Stroke Unit. Ischemic stroke subtype was classified using the TOAST classification. Blood samples were drawn within 72 h after stroke onset. Serum N-terminal probrain natriuretic peptide concentration was measured using an electrochemiluminescence immunoassay. Mean values of N-terminal probrain natriuretic peptide were compared between patients with hemorrhagic stroke vs. ischemic stroke, cardioembolic stroke vs. noncardioembolic stroke, cardioembolic stroke with atrial fibrillation vs. noncardioembolic stroke using t-test. Receiver operating characteristic curves were used to test the ability of N-terminal probrain natriuretic peptide values to identify cardioembolic stroke and cardioembolic stroke with atrial fibrillation.

Results

Ninety-two patients were included (66 with ischemic stroke) with a mean age of 58·6 years. Twenty-eight (42·4%) ischemic strokes had a cardioembolic cause. Mean N-terminal probrain natriuretic peptide values for cardioembolic stroke were significantly higher ( P < 0·001) (491·6; 95% confidence interval 283·7–852·0 pg/ml) than for noncardioembolic ischemic stroke (124·7; 86·3–180·2 pg/ml). The area under the receiver operating characteristic curve for N-terminal probrain natriuretic peptide in cardioembolic stroke was 0·77. The cut-off point with the highest sensitivity and specificity was set at 265·5 pg/ml (71·4% and 73·7% respectively). The area under the curve of N-terminal probrain natriuretic peptide for cardioembolic stroke related to atrial fibrillation was 0·92, cut-off was set at 265·5 pg/ml (sensitivity 94·4%, specificity 72·9%).

Conclusion

N-terminal probrain natriuretic peptide is a biomarker with a good accuracy to predict ischemic stroke of cardioembolic cause, namely associated with atrial fibrillation.

Early serum biomarkers of ischemic stroke

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Brain natriuretic peptide improves long-term functional recovery after acute CNS injury in mice

There is emerging evidence to suggest that brain natriuretic peptide (BNP) is elevated after acute brain injury, and that it may play an adaptive role in recovery through augmentation of cerebral blood flow (CBF). Through a series of experiments, we tested the hypothesis that the administration of BNP after different acute mechanisms of central nervous system (CNS) injury could improve functional recovery by improving CBF. C57 wild-type mice were exposed to either pneumatic-induced closed traumatic brain injury (TBI) or collagenase-induced intracerebral hemorrhage (ICH). After injury, either nesiritide (hBNP) (8 microg/kg) or normal saline were administered via tail vein injection at 30 min and 4 h. The mice then underwent functional neurological testing via rotorod latency over the following 5 days and neurocognitive testing via Morris water maze testing on days 24-28. Cerebral blood flow (CBF) was assessed by laser Doppler from 25 to 90 min after injury. After ICH, mRNA polymerase chain reaction (PCR) and histochemical staining were performed during the acute injury phase (<24 h) to determine the effects on inflammation. Following TBI and ICH, administration of hBNP was associated with improved functional performance as assessed by rotorod and Morris water maze latencies (p < 0.01). CBF was increased (p < 0.05), and inflammatory markers (TNF-alpha and IL-6; p < 0.05), activated microglial (F4/80; p < 0.05), and neuronal degeneration (Fluoro-Jade B; p < 0.05) were reduced in mice receiving hBNP. hBNP improves neurological function in murine models of TBI and ICH, and was associated with enhanced CBF and downregulation of neuroinflammatory responses. hBNP may represent a novel therapeutic strategy after acute CNS injury.

Usefulness of natriuretic peptide testing for long-term risk assessment following acute ischemic stroke

Acute-phase levels of B-type natriuretic peptide (BNP) and the N-terminal fragment of the BNP prohormone (NT-pro-BNP) have been associated with mortality when measured in patients with an acute ischemic stroke; however, data regarding the longer-term value of NT-pro-BNP for long-term prognostication after ischemic stroke are limited. Two hundred sixteen patients (mean age 67 +/- 13 years) with acute ischemic stroke were seen 6 months after index admission at which time a structured evaluation including measurement of plasma NT-pro-BNP was performed. Patients were followed for 45 months, with all-cause mortality as the clinical end point. Median NT-pro-BNP concentration for the entire group was 147 pg/ml (10th to 90th percentiles 37 to 869). At follow-up 45 patients (21%) had died. NT-pro-BNP concentrations were significantly higher in decedents (308 pg/ml, 10th to 90th percentiles 74 to 2,279) than in the 171 survivors (132 pg/ml, 10th to 90th percentiles 35 to 570, p <0.001). Patients with NT-pro-BNP < or =147 pg/ml had a significantly improved survival rate on univariate analysis (p <0.001). In multivariate analysis after adjustment for age, stroke severity, heart and renal failures, levels of NT-pro-BNP were an independent predictor of mortality >6 months after stroke (adjusted hazard ratio 1.5, 95% confidence interval 1.1 to 1.9, p = 0.005). In conclusion, NT-pro-BNP concentrations measured during the stable phase after acute ischemic stroke are strongly predictive of long-term mortality.

Heart failure may be associated with the onset of ischemic stroke with atrial fibrillation: a brain natriuretic peptide study

BACKGROUND AND PURPOSE

Congestive heart failure is a risk factor for ischemic stroke. Brain natriuretic peptide (BNP) is used as a biological marker of heart failure. We hypothesized that heart failure was associated with the onset of ischemic stroke patients with atrial fibrillation (AF).

METHODS

Between June 2006 and December 2007, we prospectively enrolled consecutive acute ischemic stroke patients with AF within 24 h of onset. Plasma BNP was measured twice, on admission and on days 28 or at discharge. As a control, we measured plasma BNP of chronic phase of stroke outpatients with AF. We investigated whether plasma BNP was elevated in the acute phase of stroke.

RESULTS

One hundred and nine patients (58 females; mean age, 76.3 years) were enrolled in the present study. Mean+/-SD of NIHSS score on admission and mRS score at discharge were 12.6+/-8.3 and 3.7+/-1.8, respectively. The interval from stroke onset to plasma BNP measurement on admission was 6.8+/-6.3 h. Moreover, follow up BNP was measured at mean of 26+/-9 days after stroke onset. The plasma BNP level in the acute phase of stroke was significantly higher than that of the subacute phase of stroke (median (interquartile range, IQR) 299.0 (176.8-469.5) vs. 149.5 (68.1-347.0) pg/ml, p<0.001). There was no significant difference in plasma BNP level between the subacute phase of stroke and control group (median (IQR) 149.5 (68.1-347.0) vs. 165.0 (64.6-224.0) pg/ml, p=0.543).

CONCLUSION

Plasma BNP was elevated in the acute phase of stroke. Heart failure may be associated with the onset of ischemic stroke patients with AF.

Correlation of NT-proBNP with diastolic left ventricular function in elderly patients with ischemic stroke

We tested the hypothesis that, in elderly survivors of ischemic stroke, high NT-proBNP levels are related with frequent diastolic dysfunction. We prospectively measured NT-proBNP, left ventricular ejection fraction (LVEF) and echographic parameters of diastolic function in 55 elderly consecutive patients, 6.8+/-2.6 days after acute ischemic stroke. We found that all the patients had systolic or diastolic dysfunction (14 had LVEF<50%, 26 mild diastolic dysfunction+LVEF > or = 50%, and 15 moderate or severe diastolic dysfunction+LVEF > or = 50%). The most powerful predictors of NT-proBNP were LVEF (R=0.38, p=0.004) and ratio of mitral E to the early diastolic velocity of the mitral annulus:E/E'(R=0.34, p=0.01).

Clinical usefulness of a biomarker-based diagnostic test for acute stroke: the Biomarker Rapid Assessment in Ischemic Injury (BRAIN) study

BACKGROUND AND PURPOSE

One of the significant limitations in the evaluation and management of patients with suspected acute cerebral ischemia is the absence of a widely available, rapid, and sensitive diagnostic test. The objective of the current study was to assess whether a test using a panel of biomarkers might provide useful diagnostic information in the early evaluation of stroke by differentiating patients with cerebral ischemia from other causes of acute neurological deficit.

METHODS

A total of 1146 patients presenting with neurological symptoms consistent with possible stroke were prospectively enrolled at 17 different sites. Timed blood samples were assayed for matrix metalloproteinase 9, brain natriuretic factor, d-dimer, and protein S100beta. A separate cohort of 343 patients was independently enrolled to validate the multiple biomarker model approach.

RESULTS

A diagnostic tool incorporating the values of matrix metalloproteinase 9, brain natriuretic factor, d-dimer, and S-100beta into a composite score was sensitive for acute cerebral ischemia. The multivariate model demonstrated modest discriminative capabilities with an area under the receiver operating characteristic curve of 0.76 for hemorrhagic stroke and 0.69 for all stroke (likelihood test P<0.001). When the threshold for the logistic model was set at the first quartile, this resulted in a sensitivity of 86% for detecting all stroke and a sensitivity of 94% for detecting hemorrhagic stroke. Moreover, results were reproducible in a separate cohort tested on a point-of-care platform.

CONCLUSIONS

These results suggest that a biomarker panel may add valuable and time-sensitive diagnostic information in the early evaluation of stroke. Such an approach is feasible on a point-of-care platform. The rapid identification of patients with suspected stroke would expand the availability of time-limited treatment strategies. Although the diagnostic accuracy of the current panel is clearly imperfect, this study demonstrates the feasibility of incorporating a biomarker based point-of-care algorithm with readily available clinical data to aid in the early evaluation and management of patients at high risk for cerebral ischemia.

The differential diagnosis of an elevated amino-terminal pro-B-type natriuretic peptide level

Although amino-terminal pro-B-type natriuretic peptides (NT-proBNP) are useful for the diagnosis or exclusion of heart failure (HF), this marker may identify a wide range of disease processes other than HF. Indeed, elevation of NT-proBNP may occur in a number of heart diseases (including heart muscle disease, valve disease, rhythm abnormalities, pulmonary hypertension, and cytotoxic injury to the heart) and in disease processes other than primary cardiac illnesses, including gram-negative sepsis. Importantly, although NT-proBNP may increase in settings other than HF, the presence and severity of such NT-proBNP release is often significantly associated with risk for adverse outcome. Accordingly, elevation of NT-proBNP in the context of non-HF situations should not be regarded as a "false-positive" finding, and elevated NT-proBNP values should not be discarded without consideration of the serious adverse outcomes associated with the elevation. Future studies will be necessary to further understand the utility of NT-proBNP testing in states other than cardiovascular disease.

Plasmatic B-type natriuretic peptide and C-reactive protein in hyperacute stroke as markers of CT-evidence of brain edema

OBJECTIVE

Plasmatic B-type-natriuretic peptide (NT-PBNP) and C-reactive protein (CRP) have been reportedly elevated in stroke patients; however their clinical significance remains uncertain. The purpose of this work is to investigate whether elevation of these proteins at baseline predicts CT-evidence of brain edema.

METHODS

We recruited 41 consecutive patients with stroke and determined NT-PBNP and CRP at baseline (within 5 hours after onset), after 48-72 hours, and at discharge. Stroke severity was measured by means of the NIHS scale at baseline and at discharge. We also carried out brain CT at admittance and after 48 hours.

RESULTS

There were 29 ischemic strokes and 12 hemorrhagic strokes. Evidence of brain edema on delayed scan was seen in 14 patients. Baseline levels of NT-PBNP did not predict CT-evidence of edema but CRP levels did so significantly (0.7 mg/dl in patients without edema versus 4.7 mg in patients with edema; p=0.001). Both NT-PBNP and PC levels correlated poorly to NIHSS score and increased markedly from baseline to the second determination in patients with edema. For these patients the NT-PBNP increase was 133.6 pmol/l in comparison to 1.58 pmol/l in patients without edema (p=0.002). Neither CRP nor NT-PBNP baseline levels were predictive of dependency or death.

CONCLUSIONS

We conclude that CRP at baseline but not NT-PBNP predicts CT evidence of brain edema in stroke patients. We hypothesize that NT-PBNP levels elevated in response to edema after 48 hours of admission.

Natriuretic peptides

Natriuretic peptides (NPs) are released from the heart in response to pressure and volume overload. B-type natriuretic peptide (BNP) and N-terminal-proBNP have become important diagnostic tools for assessing patients who present acutely with dyspnea. The NP level reflects a compilation of systolic and diastolic function as well as right ventricular and valvular function. Studies suggest that using NPs in the emergency department can reduce the consumption of hospital resources and can lower costs by either eliminating the need for other, more expensive tests or by establishing an alternative diagnosis that does not require hospital stay. Caveats such as body mass index and renal function must be taken into account when analyzing NP levels. Natriuretic peptide levels have important prognostic value in multiple clinical settings, including in patients with stable coronary artery disease and with acute coronary syndromes. In patients with decompensated heart failure due to volume overload, a treatment-induced drop in wedge pressure is often accompanied by a rapid drop in NP levels. Knowing a patient's NP levels might thus assist with hemodynamic assessment and subsequent treatment titration. Monitoring NP levels in the outpatient setting might also improve patient care and outcomes.

The influence of anaemia on stroke prognosis and its relation to N-terminal pro-brain natriuretic peptide

Anaemia is a negative prognostic factor for patients with heart failure and impaired renal function, but its role in stroke patients is unknown. Furthermore, anaemia has been shown to influence the level of N-terminal pro-brain natriuretic peptide (NT-proBNP), but this is only investigated in patients with heart failure, not in stroke patients. Two-hundred-and-fifty consecutive, well-defined ischemic stroke patients were investigated. Mortality was recorded at 6 months follow-up. Anaemia was diagnosed in 37 patients (15%) in whom stroke severity was worse than in the non-anaemic group, whilst the prevalence of renal affection, smoking and heart failure was lower. At 6 months follow-up, 23 patients were dead, and anaemia had an odds ratio of 4.7 when adjusted for age, Scandinavian Stroke Scale and a combined variable of heart and/or renal failure and/or elevation of troponin T using logistic regression. The median NT-proBNP level in the anaemic group was significantly higher than in the non-anaemic group, and in a multivariate linear regression model, anaemia remained an independent predictor of NT-proBNP. Conclusively, anaemia was found to be a negative prognostic factor for ischemic stroke patients. Furthermore, anaemia influenced the NT-proBNP level in ischemic stroke patients, an important aspect when interpreting NT-proBNP in these patients.