Potential biomarkers for predicting hemorrhagic transformation of ischemic stroke

Artificial intelligence/machine learning for neuroimaging to predict hemorrhagic transformation: Systematic review/meta-analysis

BACKGROUND AND PURPOSE

Early and reliable prediction of hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS) is crucial for treatment decisions and early intervention. The purpose of this study was to conduct a systematic review and meta-analysis on the performance of artificial intelligence (AI) and machine learning (ML) models that utilize neuroimaging to predict HT.

METHODS

A systematic search of PubMed, EMBASE, and Web of Science was conducted until February 19, 2024. Inclusion criteria were as follows: patients with AIS who received reperfusion therapy; AI/ML algorithm using imaging to predict HT; or presence of sufficient data on the predictive performance. Exclusion criteria were as follows: articles with less than 20 patients; articles lacking algorithms that operate solely on images; or articles not detailing the algorithm used. The quality of eligible studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 and Checklist for Artificial Intelligence in Medical Imaging. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated using a random-effects model, and a summary receiver operating characteristic curve was constructed using the Reitsma method.

RESULTS

We identified six eligible studies, which included 1640 patients. Aside from an unclear risk of bias regarding flow and timing identified in two of the studies, all studies showed low risk of bias and applicability concerns in all categories. Pooled sensitivity, specificity, and DOR were .849, .878, and 45.598, respectively.

CONCLUSION

AI/ML models can reliably predict the occurrence of HT in AIS patients. More prospective studies are needed for subgroup analyses and higher clinical certainty and usefulness.

Prediction of cerebral hemorrhagic transformation after thrombectomy using a deep learning of dual-energy CT

OBJECTIVES

To develop and validate a deep learning model for predicting hemorrhagic transformation after endovascular thrombectomy using dual-energy computed tomography (CT).

MATERIALS AND METHODS

This was a retrospective study from a prospective registry of acute ischemic stroke. Patients admitted between May 2019 and February 2023 who underwent endovascular thrombectomy for acute anterior circulation occlusions were enrolled. Hemorrhagic transformation was defined using follow-up magnetic resonance imaging or CT. The deep learning model was developed using post-thrombectomy dual-energy CT to predict hemorrhagic transformation within 72 h. Temporal validation was performed with patients who were admitted after July 2022. The deep learning model's performance was compared with a logistic regression model developed from clinical variables using the area under the receiver operating characteristic curve (AUC).

RESULTS

Total of 202 patients (mean age 71.4 years ± 14.5 [standard deviation], 92 men) were included, with 109 (54.0%) patients having hemorrhagic transformation. The deep learning model performed consistently well, showing an average AUC of 0.867 (95% confidence interval [CI], 0.815-0.902) upon five-fold cross validation and AUC of 0.911 (95% CI, 0.774-1.000) with the test dataset. The clinical variable model showed an AUC of 0.775 (95% CI, 0.709-0.842) on the training dataset (p < 0.01) and AUC of 0.634 (95% CI, 0.385-0.883) on the test dataset (p = 0.06).

CONCLUSION

A deep learning model was developed and validated for prediction of hemorrhagic transformation after endovascular thrombectomy in patients with acute stroke using dual-energy computed tomography.

CLINICAL RELEVANCE STATEMENT

This study demonstrates that a convolutional neural network (CNN) can be utilized on dual-energy computed tomography (DECT) for the accurate prediction of hemorrhagic transformation after thrombectomy. The CNN achieves high performance without the need for region of interest drawing.

KEY POINTS

• Iodine leakage on dual-energy CT after thrombectomy may be from blood-brain barrier disruption. • A convolutional neural network on post-thrombectomy dual-energy CT enables individualized prediction of hemorrhagic transformation. • Iodine leakage is an important predictor of hemorrhagic transformation following thrombectomy for ischemic stroke.

Biochemical, biomechanical and imaging biomarkers of ischemic stroke: Time for integrative thinking

Stroke is one of the leading causes of adult disability affecting millions of people worldwide. Post-stroke cognitive and motor impairments diminish quality of life and functional independence. There is an increased risk of having a second stroke and developing secondary conditions with long-term social and economic impacts. With increasing number of stroke incidents, shortage of medical professionals and limited budgets, health services are struggling to provide a care that can break the vicious cycle of stroke. Effective post-stroke recovery hinges on holistic, integrative and personalized care starting from improved diagnosis and treatment in clinics to continuous rehabilitation and support in the community. To improve stroke care pathways, there have been growing efforts in discovering biomarkers that can provide valuable insights into the neural, physiological and biomechanical consequences of stroke and how patients respond to new interventions. In this review paper, we aim to summarize recent biomarker discovery research focusing on three modalities (brain imaging, blood sampling and gait assessments), look at some established and forthcoming biomarkers, and discuss their usefulness and complementarity within the context of comprehensive stroke care. We also emphasize the importance of biomarker guided personalized interventions to enhance stroke treatment and post-stroke recovery.

Prediction factors and clinical significance of different types of hemorrhagic transformation after intravenous thrombolysis

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) after intravenous thrombolysis (IVT) in acute ischemic stroke seriously affects the prognosis of patients. This study aimed to investigate the risk factors of different types of HT and their correlation with prognosis after IVT.

METHODS

Based on the CASE II registry, we included patients with acute ischemic stroke who received IVT within 4.5 h of onset. HT was further divided into hemorrhagic infarction (HI) and parenchymal hemorrhage (PH). Poor outcome was defined as a modified Rankin Scale (mRS) score of 3-6 at 3 months. Multivariate logistic regression analysis was used to determine the independent influencing factors of HT subtypes and clinical outcome.

RESULTS

Among 13108 included patients, 541 (4.1%) developed HI and 440 (3.4%) developed PH. In multivariate analysis, age (OR 1.038, 95% CI 1.028 to 1.049, p < 0.001), atrial fibrillation (OR 1.446, 95% CI 1.141 to 1.943, p = 0.002), baseline diastolic pressure (OR 1.012, 95% CI 1.004 to 1.020, p = 0.005), baseline NIHSS score (OR 1.060, 95% CI 1.049 to 1.071, p < 0.001) and onset to treatment time (OR 1.002, 95% CI 1.000 to 1.004, p = 0.020) independently predicted PH after IVT. In the patients with HT, PH (OR 3.611, 95% CI 2.540 to 5.134, p < 0.001) and remote hemorrhage (OR 1.579, 95% CI 1.115 to 2.235, p = 0.010) were independently related to poor outcome.

CONCLUSIONS

Different types of HT after IVT had different risk factors and clinical significance. The occurrence of PH and remote hemorrhage independently increased the risk of poor outcome.

Non-contrast assessment of blood-brain barrier permeability to water in mice: An arterial spin labeling study at cerebral veins

Blood-brain barrier (BBB) plays a critical role in protecting the brain from toxins and pathogens. However, in vivo tools to assess BBB permeability are scarce and often require the use of exogenous contrast agents. In this study, we aimed to develop a non-contrast arterial-spin-labeling (ASL) based MRI technique to estimate BBB permeability to water in mice. By determining the relative fraction of labeled water spins that were exchanged into the brain tissue as opposed to those that remained in the cerebral veins, we estimated indices of global BBB permeability to water including water extraction fraction (E) and permeability surface-area product (PS). First, using multiple post-labeling delay ASL experiments, we estimated the bolus arrival time (BAT) of the labeled spins to reach the great vein of Galen (VG) to be 691.2 ± 14.5 ms (N = 5). Next, we investigated the dependence of the VG ASL signal on labeling duration and identified an optimal imaging protocol with a labeling duration of 1200 ms and a PLD of 100 ms. Quantitative E and PS values in wild-type mice were found to be 59.9 ± 3.2% and 260.9 ± 18.9 ml/100 g/min, respectively. In contrast, mice with Huntington's disease (HD) revealed a significantly higher E (69.7 ± 2.4%, P = 0.026) and PS (318.1 ± 17.1 ml/100 g/min, P = 0.040), suggesting BBB breakdown in this mouse model. Reproducibility studies revealed a coefficient-of-variation (CoV) of 4.9 ± 1.7% and 6.1 ± 1.2% for E and PS, respectively. The proposed method may open new avenues for preclinical research on pathophysiological mechanisms of brain diseases and therapeutic trials in animal models.

In Vivo Evaluation of BBB Integrity in the Post-stroke Brain

The blood-brain barrier (BBB) is a dynamic interface responsible for maintaining central nervous system (CNS) homeostasis. An intact BBB protects the brain from undesired compounds and proteins from the blood; however, BBB impairment is involved in various pathological conditions including stroke. In vivo evaluation of BBB integrity in the post-stroke brain is important for investigating stroke-induced CNS pathogenesis and developing CNS-targeted therapeutic agents. In this chapter, we describe both quantitative and morphometric methods and tools to evaluate BBB integrity in vivo. These methods do not require expensive magnetic resonance imaging (MRI) and computed tomography (CT) imaging capabilities and can be conducted in research laboratories with access to a confocal microscope and fluorescence microplate reader.

The diagnostic and prognostic value of serum neurogranin in acute ischemic stroke

OBJECTIVES

Stroke is a frequently encountered life-threatening medical condition in emergency departments (EDs). Despite all worldwide efforts, a reliable circulating biomarker has not been identified yet. This study investigates the diagnostic and prognostic value of neurogranin (Ng) in acute ischemic stroke (AIS).

METHODS

This prospective case-control study was conducted on ED patients with AIS and healthy volunteers. We collected the basic demographics, measured serum Ng levels of the patients vs. controls, and followed up the patient group for 6-month by phone or clinical notes to assess the functional outcomes.

RESULTS

Data analysis was completed with 142 subjects (86 patients vs. 55 controls). The groups did not differ in terms of age and gender. The median serum Ng level of the patient group was significantly higher compared to the control group [160.00 (75.93) vs. 121.26 (90.35) ng/mL and p ˂ 0.001, respectively]. Serum Ng level of 25 patients admitted to the ED within the first 6 hours from the onset of AIS was 177.93 (24.03) ng/mL, while serum Ng level of 61 patients admitted to the ED within 6-24 hours was 131.84 (76.44) ng/mL. AUROC results were 0.717 vs. 0.868 vs. 0.874 for stroke patients admitted during the first 24 hours, 6 hours, and 4.5 hours after the onset, respectively. Lesion volume, NIHSS, and modified Rankin Scale scores (mRS) at admission showed no significant correlation with Ng levels as well as 6-month mortality and 6-month mRS.

CONCLUSIONS

Timely AIS diagnosis is still a challenge for emergency departments due to the dependency on imaging. Serum Ng can be a promising diagnostic biomarker for AIS patients admitted in the first 24 hours. Even it outperformed in the first 4.5 and 6-hour time windows. However, it did not show a significant prognostic value.

Predictive Value of CT Perfusion in Hemorrhagic Transformation after Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Background: Existing studies indicate that some computed tomography perfusion (CTP) parameters may predict hemorrhagic transformation (HT) after acute ischemic stroke (AIS), but there is an inconsistency in the conclusions alongside a lack of comprehensive comparison. Objective: To comprehensively evaluate the predictive value of CTP parameters in HT after AIS. Data sources: A systematical literature review of existing studies was conducted up to 1st October 2022 in six mainstream databases that included original data on the CTP parameters of HT and non-HT groups or on the diagnostic performance of relative cerebral blood flow (rCBF), relative permeability-surface area product (rPS), or relative cerebral blood volume (rCBV) in patients with AIS that completed CTP within 24 h of onset. Data Synthesis: Eighteen observational studies were included. HT and non-HT groups had statistically significant differences in CBF, CBV, PS, rCBF, rCBV, and rPS (p < 0.05 for all). The hierarchical summary receiver operating characteristic (HSROC) revealed that rCBF (area under the curve (AUC) = 0.9), rPS (AUC = 0.89), and rCBV (AUC = 0.85) had moderate diagnostic performances in predicting HT. The pooled sensitivity and specificity of rCBF were 0.85 (95% CI, 0.75−0.91) and 0.83 (95% CI, 0.63−0.94), respectively. Conclusions: rCBF, rPS, and rCBV had moderate diagnostic performances in predicting HT, and rCBF had the best pooled sensitivity and specificity.

Post-operative neutrophil-to-lymphocyte ratio and outcome after thrombectomy in acute ischemic stroke

Background

Neutrophil to lymphocyte ratio (NLR) is a novel inflammatory marker to predict adverse cardiovascular events. However, there is a lack of data on hemorrhagic transformation (HT) and neurological outcome after mechanical thrombectomy in acute ischemic stroke (AIS). We investigated whether NLR before and after thrombectomy for patients with AIS was associated with HT and neurological outcomes.

Methods

We performed a retrospective analysis of consecutive patients with anterior circulation AIS who underwent thrombectomy. HT was evaluated by CT within 24 h after thrombectomy. Clinical data had been collected retrospectively; laboratory data were extracted from our electronic hospital information system. NLR was obtained at admission (NLR1) and immediately after thrombectomy (NLR2). The main outcomes were post-interventional intracranial hemorrhage and unfavorable functional status (modified Rankin scale scores of 3–6) 3 months post-stroke.

Results

A total of 258 patients with AIS, according to the NIHSS (median 14), were included. NLR2 was higher in patients who developed HT after thrombectomy and unfavorable neurological outcomes 3 months post-stroke (p < 0.001) than in those without HT or favorable outcomes, even after correction for co-factors [Odds Ratio (OR) 1.35 for HT, 95% confidence interval (CI)1.16–1.57, p < 0.001, and 1.85 for unfavorable outcome, 95%CI 1.57–2.17, p < 0.001]. The optimal cutoff value for the NLR2 as an indicator for auxiliary diagnosis of HT and the unfavorable outcome was 8.4 and 8.8, respectively.

Conclusion

NLR immediately after thrombectomy is a readily available biomarker of HT and neurological outcomes in patients with AIS.

Lower uric acid level may be associated with hemorrhagic transformation after intravenous thrombolysis

BACKGROUND

Previous studies have shown that uric acid (UA) is a powerful water-soluble antioxidant and free radical scavenger for humans. However, the relationship between serum uric acid (SUA) and hemorrhagic transformation (HT) is still controversial. To address this challenge, we aimed to explore the association between serum UA and HT in patients with acute ischemic stroke (AIS) after intravenous thrombolysis (IVT).

METHODS

A retrospective analysis was conducted in patients with anterior circulation AIS who underwent IVT at Affiliated Hospital of Qingdao University from 2016 to 2021. HT was evaluated by CT or MRI within 7 days after admission. Baseline demographic, clinical, and laboratory data were compared between the HT and non-HT groups, and between different types of HT groups which were documented according to the European Cooperative Acute Stroke Study III Classification (ECASS III).

RESULTS

A total of 727 AIS patients were enrolled, including 112 patients who experienced HT (HT group) and 615 patients who did not experience HT (non-HT group). Patients with HT had significantly lower UA levels compared to those without HT (253.65 ± 97.75 vs 315.97 ± 96.42, p < 0.001); however, there was no significant difference for UA levels in different types of HT (p = 0.907). After adjusting confounders, patients in the fourth UA quartile showed a significant decrease in HT compared with those in the first quartile (OR 0.266, 95% CI 0.107-0.661, p = 0.006). The best cutoff value was identified as 218.5 μmol/L after analysis.

CONCLUSIONS

These findings suggest that low levels of UA may be associated with HT after IVT.

U-Shaped Association Between Serum Uric Acid and Hemorrhagic Transformation After Intravenous Thrombolysis

BACKGROUND

Uric acid (UA) has both antioxidative and pro-oxidative properties. The study aimed to investigate the relationship between serum UA and hemorrhagic transformation (HT) after intravenous thrombolysis in patients with acute ischemic stroke.

METHODS

The patients undergoing intravenous thrombolysis from two hospitals in China were retrospectively analyzed. HT was evaluated using computed tomography images reviewed within 24- 36h after thrombolysis. Symptomatic intracranial hemorrhage (sICH) was defined as HT accompanied by worsening neurological function. Multivariate logistic regression and spline regression models were performed to explore the relationship between serum UA levels and the risk of HT and sICH.

RESULTS

Among 503 included patients, 60 (11.9%) were diagnosed with HT and 22 (4.4%) developed sICH. Patients with HT had significant lower serum UA levels than those without HT (245 [214-325 vs. 312 [256-370] μmol/L, p < 0.001). Multivariable logistic regression analysis indicated that patients with higher serum UA levels had a lower risk of HT (OR per 10-μmol/L increase 0.96, 95%CI 0.92-0.99, p = 0.015). Furthermore, multiple-adjusted spline regression models showed a Ushaped association between serum UA levels and HT (p < 0.001 for non-linearity). Similar results were present between serum UA and sICH. Restricted cubic spline models predicted the lowest risk of HT and sICH when the serum UA levels were 386μmol/L.

CONCLUSION

The data show the U-shaped relationship between serum UA levels and the risk of HT and sICH after intravenous thrombolysis.

Pharmacological brain cytoprotection in acute ischaemic stroke — renewed hope in the reperfusion era

For over 40 years, attempts to develop treatments that protect neurons and other brain cells against the cellular and biochemical consequences of cerebral ischaemia in acute ischaemic stroke (AIS) have been unsuccessful. However, the advent of intravenous thrombolysis and endovascular thrombectomy has taken us into a new era of treatment for AIS in which highly effective reperfusion therapy is widely available. In this context, cytoprotective treatments should be revisited as adjunctive treatment to reperfusion therapy. Renewed efforts should focus on developing new drugs that target multiple aspects of the ischaemic cascade, and previously developed drugs should be reconsidered if they produced robust cytoprotective effects in preclinical models and their safety profiles were reasonable in previous clinical trials. Several development pathways for cytoprotection as an adjunct to reperfusion can be envisioned. In this Review, we outline the targets for cytoprotective therapy and discuss considerations for future drug development, highlighting the recent ESCAPE-NA1 trial of nerinetide, which produced the most promising results to date. We review new types of clinical trial to evaluate whether cytoprotective drugs can slow infarct growth prior to reperfusion and/or ameliorate the consequences of reperfusion, such as haemorrhagic transformation. We also highlight how advanced brain imaging can help to identify patients with salvageable ischaemic tissue who are likely to benefit from cytoprotective therapy.

In this Review, Fisher and Savitz consider how the era of reperfusion therapy in ischaemic stroke provides new hope for the development of cytoprotective therapies to further improve outcomes, highlighting how promising recent findings can be built on to benefit patients.

Highly successful reperfusion therapy with intravenous thrombolysis and endovascular thrombectomy is now widely available for the treatment of acute ischaemic stroke, making cytoprotective therapy a viable additional treatment approach.

Previous attempts to develop cytoprotective therapy have been unsuccessful, but this approach should now be reconsidered as an adjunctive therapy to thrombolysis and thrombectomy.

New cytoprotective drugs should be developed to target multiple aspects of the ischaemic cascade, and previously developed drugs should be reconsidered.

Trials should be conducted to evaluate the effects of cytoprotective drugs when administered before or after reperfusion therapy or both.

Advanced brain imaging should be used to select patients who are most likely to benefit from cytoprotective treatment for enrolment in new trials.

Hemorrhagic Transformation After Ischemic Stroke: Mechanisms and Management

Symptomatic hemorrhagic transformation (HT) is one of the complications most likely to lead to death in patients with acute ischemic stroke. HT after acute ischemic stroke is diagnosed when certain areas of cerebral infarction appear as cerebral hemorrhage on radiological images. Its mechanisms are usually explained by disruption of the blood-brain barrier and reperfusion injury that causes leakage of peripheral blood cells. In ischemic infarction, HT may be a natural progression of acute ischemic stroke and can be facilitated or enhanced by reperfusion therapy. Therefore, to balance risks and benefits, HT occurrence in acute stroke settings is an important factor to be considered by physicians to determine whether recanalization therapy should be performed. This review aims to illustrate the pathophysiological mechanisms of HT, outline most HT-related factors after reperfusion therapy, and describe prevention strategies for the occurrence and enlargement of HT, such as blood pressure control. Finally, we propose a promising therapeutic approach based on biological research studies that would help clinicians treat such catastrophic complications.

Increased Platelet-to-Lymphocyte Ratio is an Independent Predictor of Hemorrhagic Transformation and In-Hospital Mortality Among Acute Ischemic Stroke with Large-Artery Atherosclerosis Patients

Background

The platelet-to-lymphocyte ratio (PLR) is an inflammation marker of acute ischemic stroke, but its significance in patients with hemorrhage transformation (HT) after acute ischemic stroke with large-artery atherosclerosis (AIS-LAA) is unclear, and we also identified the relationship between PLR and in-hospital mortality of HT after AIS-LAA.

Methods

This was a retrospective analysis of patients with AIS-LAA. The PLR was calculated according to platelet and lymphocyte counts on admission. HT was defined on follow-up magnetic resonance imaging or computed tomography when neurologic deterioration worsened during hospitalization. The univariate analysis and multivariate logistic regression were performed to assess the association of PLR, HT and in-hospital mortality of HT after AIS-LAA.

Results

We included 328 Chinese AIS-LAA patients (mean age 67.2±11.1 years; 70.4% male). HT occurred in 38 patients (11.6%). After multivariate regression analyses, NRL (odds ratio [OR] 1.354, 95% confidence interval [CI] 1.176–1.559, P<0.001) and PLR (odds ratio [OR] 3.869, 95% confidence interval [CI] 2.233–5.702, P<0.001) were independently associated with HT after AIS-LAA. The area under the ROC curve (AUC) value of PLR (0.72, 95% CI (0.64–0.80), P<0.001) tested a greater discriminatory ability compared with neutrophil-lymphocyte ratio (NLR) (0.67, 95% CI (0.58–0.76), P<0.001). Meanwhile, PLR was found to be significantly related to HT after AIS-LAA, including in subtypes of artery-to-artery embolization (aOR 1.699, 95% CI 1.298–3.215, P<0.001), in-situ thrombosis (aOR4.499, 95% CI 1.344–9.054, P<0.001) and branch atheromatous disease (aOR3.239, 95% CI 1.098–8.354, P<0.001). Increased PLR predicts high in-hospital mortality of HT after AIS-LAA (OR 1.041, 95% CI (1.006–1.077), P=0.020; aOR 1.053, 95% CI (1.004–1.104), P=0.034).

Conclusion

High PLR is associated with greater risk of HT in AIS-LAA patients, including in artery-to-artery embolization, in-situ thrombosis and branch atheromatous disease. Meanwhile, increased PLR predicts high in-hospital mortality of HT after AIS-LAA.

Different Scores Predict the Value of Hemorrhagic Transformation after Intravenous Thrombolysis in Patients with Acute Ischemic Stroke

Objective

To evaluate the value of the Alberta stroke project early CT score (ASPECTS), DRAGON score, SEDAN score, and HAT score in predicting hemorrhagic transformation (HT) after intravenous thrombolysis in patients with acute ischemic stroke (AIS).

Methods

The clinical data of 248 AIS patients treated with intravenous thrombolysis in our hospital from December 2017 to December 2019 were analyzed. According to the prognosis, all patients were divided into the non-HT group (n = 200) and the HT group (n = 48). Univariate analysis and multivariate logistic regression models were used to analyze clinical data to determine the influencing factors of HT after intravenous thrombolysis in AIS patients. The receiver operating characteristic curve was used to evaluate the ASPECTS, DRAGON, SEDAN, and HAT scores to the value of predicting HT after intravenous thrombolysis in AIS patients.

Results

The lower the ASPECTS score and the higher the DRAGON, SEDAN, and HAT scores, the higher the incidence of HT after intravenous thrombolysis in AIS patients (P < 0.05). The results of multivariate logistic regression analysis showed that the patient's age, atrial fibrillation, baseline NIHSS score, early signs of infarction on admission with head CT, time from onset to thrombolytic therapy, and thrombolytic drugs were all independent factors affecting intravenous thrombolysis in AIS patients (P < 0.05). The area under the curve (AUC) of the predictive value of ASPECTS for HT is 0.895 (95% CI 0.813–0.977). When the optimal cutoff value is 0.607, the sensitivity is 100% and the specificity is 60.7%. The AUC of the predictive value of DRAGON for HT is 0.877 (95% CI 0.790–0.964). When the optimal cutoff value is 0.665, the sensitivity is 84.4% and the specificity is 82.1%. The AUC of the predictive value of SEDAN for HT is 0.764 (95% CI 0.638–0.890). When the optimal cutoff value is 0.474, the sensitivity is 78.6% and the specificity is 68.8%. The AUC of the predictive value of HAT for HT is 0.777 (95% CI 0.651–0.903). When the optimal cutoff value is 0.509, the sensitivity is 68.8% and the specificity is 82.1%.

Conclusion

The lower the ASPECTS score and the higher the DRAGON, SEDAN, and HAT scores, the higher the incidence of HT in AIS patients. The patient's age, atrial fibrillation, baseline NIHSS score, early signs of infarction on admission with head CT, time from onset to thrombolytic therapy, and thrombolytic drugs are all independent factors affecting HT in AIS patients. The scores of ASPECTS, DRAGON, SEDAN and HAT have certain value in predicting HT after intravenous thrombolysis in AIS patients, and the predicted value of ASPECTS score is the best.

Troponin Elevation on Admission Along With Dynamic Changes and Their Association With Hemorrhagic Transformation After Thrombolysis

Background: Hemorrhagic transformation (HT) is a common complication of intravenous thrombolysis with alteplase. Cardiac troponin has been found to be associated with poor prognosis and cognitive impairment in acute ischemic stroke. But studies on the relationship between troponin and HT after thrombolysis are scarce. Methods: This study retrospectively analyzed thrombolytic patients from June 2015 to June 2021 in the Second Affiliated Hospital of Wenzhou Medical University. Cardiac troponin I were measured on admission and on following days to determine the presence of elevation and dynamic changes. HT within 24-36 h after treatment was identified by cranial computed tomography (CT). Besides, a score on the modified Rankin Scale (mRS) > 2 at discharge was defined as unfavorable outcome. Univariate analysis was used to explore the factors related to the troponin elevation on admission and troponin dynamic changes. Multivariate logistic regression model was used to investigated the association between troponin elevation on admission, troponin dynamic changes and HT after thrombolysis, respectively. Results: Troponin levels on admission were measured in 377 patients, and follow-up assay was performed in 292 patients (77.5%). 39 patients (10.3%) had troponin elevation on admission, and 66 patients (22.6%) had troponin dynamic changes comprising rising and falling pattern. The pre-existing heart disease, renal insufficiency and higher stroke severity are related to both troponin elevation on admission and the subsequent troponin dynamic changes. After adjusting the potential confounding factors, logistic regression model showed that patients with troponin elevation on admission had insignificant trend to develop HT (OR 2.23, 95%CI 0.96-5.21, p = 0.063), while patients with troponin dynamic changes had significantly higher risk of HT (OR 2.27, 95%CI 1.06-4.85, p = 0.034). Compared to the troponin elevation, a statistically stronger association was present between rising troponin dynamic changes and unfavorable outcome (OR 2.20, 95%CI 1.05-4.60, p = 0.037). Conclusion: Troponin dynamic changes are associated with HT after thrombolysis. Serial measurements are quite necessary in thrombolytic patients with risk factors associated with troponin dynamic changes (e.g., advanced age, pre-existing heart disease, higher NIHSS score, and troponin elevation on admission).

Neutrophil-lymphocyte ratio in acute ischemic stroke: Immunopathology, management, and prognosis

There is an ongoing need for accurate prognostic biomarkers in the milieu of acute ischemic stroke (AIS) receiving reperfusion therapy. Neutrophil-lymphocyte ratio (NLR) has been implicated in emergency medicine and acute stroke setting as an important biomarker in the prognosis of patients. However, there are ongoing questions around its accuracy and translation into clinical practice given suboptimal sensitivity and specificity results, as well as varying thresholds and lack of clarity around which NLR time points are most clinically indicative. This article provides a comprehensive overview of the role of NLR in AIS patients receiving reperfusion therapy and perspectives on areas of future research. NLR may be an important biomarker in risk stratifying patients in AIS to identify and select those who are more likely to benefit from reperfusion therapy. Appropriate clinical decision-making tools and models are required to harness the predictive value of NLR, which could be useful in identifying and monitoring high-risk patients to guide early treatment and achieve improved outcomes. Our understanding of the role of NLR in the immunopathogenesis of AIS is also suboptimal, which hinders the ability to translate this into clinical practice.

Predictive Value of Apelin and Vaspin on Hemorrhagic Transformation in Patients with Acute Ischemic Stroke after Intravenous Thrombolysis and Analysis of Related Factors

BACKGROUND

Acute ischemic stroke (CIS) is a high-risk condition among the elderly, and intravenous thrombolytic therapy (ITT) is the most effective means for it. However, ITT is prone to induce hemorrhagic transformation (HT) that further threatens the life and health of patients. As paramount substances in cardiovascular and cerebrovascular diseases, adipocyte factor (Apelin) and serine protease inhibitor (Vaspin) are strongly bound up with CIS.

OBJECTIVE

To analyze the predictive significance of Apelin and Vaspin on HT in CIS patients after ITT and offer effective reference to HT prevention in the future.

METHODS

A total of 109 CIS patients treated with intravenous thrombolysis (IT) in two hospitals between June 2017 and February 2018 were enrolled. Among them, 48 patients who suffered HT after therapy were assigned to the research group (Res group) and the other 61 patients who did not suffer it after therapy were assigned to the control group (Con group). Serum Apelin, Vaspin, inflammatory factors, and oxidative stress levels were quantified, and receiver operating characteristic (ROC) curves were drawn for analyzing the predictive value of Apelin and Vaspin on HT after ITT and their associations with inflammatory factors and oxidative stress. CIS patients who suffered HT were followed up for 3 years for prognostic significance analysis of Apelin and Vaspin.

RESULTS

After ITT, the Res group showed lower Apelin and Vaspin levels than the Con group (all P < 0.05), and patients with a higher HT grade had lower Apelin and Vaspin levels (all P < 0.05). The joint detection of Apelin and Vaspin showed a sensitivity of 77.08% and a specificity of 73.77% for forecasting HT in CIS patients after thrombolytic therapy (all P < 0.001). In addition, after thrombolytic therapy, the Res group presented higher levels of interleukin-1β (IL-1β) and IL-6 as well as malondialdehyde (MDA) than the Con group, and the levels had negative associations with Apelin and Vaspin (all P < 0.05). The Res group showed a lower superoxide dismutase (SOD) level than the Con group, and the level presented a positive association with Apelin and Vaspin (all P < 0.05). According to Logistic analysis, IL-1β, IL-6, and MDA were independent risk factors for HT in CIS patients after IT, while Apelin, Vaspin, and SOD were independent protective factors (all P < 0.05). According to the follow-up results, Apelin and Vaspin demonstrated excellent value in forecasting the death of patients with both CIS and HT (P < 0.05), and their lower levels indicate a higher risk of death (all P < 0.05).

CONCLUSION

Apelin and Vaspin can help effectively forecast the occurrence of HT in CIS patients after ITT as independent protective factors of HT, so they are of a high clinical application value.

Fibrinogen Level Combined With Platelet Count for Predicting Hemorrhagic Transformation in Acute Ischemic Stroke Patients Treated With Mechanical Thrombectomy

A serious complication of acute ischemic stroke (AIS) after mechanical thrombectomy (MT) is hemorrhagic transformation (HT), which is potentially associated with clinical deterioration. This study examined predictors of HT following MT in AIS patients. Patients with AIS due to large artery occlusion in the anterior circulation, treated with MT and successfully recanalized (modified Thrombolysis in Cerebral Infarction score 2b/3), were studied retrospectively. HT was evaluated by computed tomography (CT) 24 h after MT and was diagnosed and classified into parenchymal hematoma (PH) and hemorrhagic infarction (HI). Multivariate logistic regression models were used to determine the risk factors for HT. Receiver operating characteristic (ROC) curve analysis was performed to determine the predictive utility of risk factors for HT. We enrolled 135 patients: 49 in the HT group and 86 in the non-HT group. The two groups differed significantly in baseline fibrinogen levels (p = 0.003) and platelet counts (p = 0.006). Multivariate logistic regression analyses showed that lower fibrinogen levels [odds ratio (OR), 0.41; 95% CI, 0.23–0.72; p = 0.002] and platelet counts (OR, 0.58; 95% CI, 0.33–0.99; p = 0.048) were independently associated with a higher risk of HT. Together, the binary variates fibrinogen and platelets well-predicted HT (area under the curve, 0.703; specificity, 77.9%; sensitivity, 55.1%). The combination of fibrinogen <2.165 g/L and platelets <171.5 × 10⁹/L was the strongest predictor of HT (OR, 23.17; 95% CI, 5.75–126.80; p < 0.0001). Our study suggests that lower baseline fibrinogen levels and platelet counts may be risk factors for HT in AIS patients following MT and reperfusion. Specifically, the combination of fibrinogen level and platelet count may predict the risk of HT after MT in these patients.

Increased systemic immune-inflammation index predicts hemorrhagic transformation in anterior circulation acute ischemic stroke due to large-artery atherosclerotic

BACKGROUND AND PURPOSE

Inflammation and immune response play an important role in hemorrhage transformation after acute ischemic stroke. According to previous studies, systemic immune-inflammation index is associated with severity of stroke. We aimed to evaluate the association between systemic immune-inflammation index and hemorrhage transformation in anterior circulation acute ischemic stroke due to large-artery atherosclerosis.

METHODS

This was a retrospective analysis of patients with anterior circulation acute ischemic stroke due to large-artery atherosclerosis. The laboratory data were collected within 24 h after admission. Hemorrhage transformation was defined on follow-up magnetic resonance imaging or Computed Tomography. The univariate analysis and multivariate logistic regression were performed to assess the association of systemic immune-inflammation index with hemorrhage transformation. Then the relationship between systemic immune-inflammation index and hemorrhage transformation in different stroke subtypes was further studied.

RESULTS

We included 310 Chinese anterior circulation acute ischemic stroke patients due to large-artery atherosclerosis (mean age 65 ± 11.4 years; 72.6% male). Hemorrhage transformation occurred in 41 patients (13.2%). After multivariate regression analyses, systemic immune-inflammation index (odds ratio [OR] 1.109, 95% Confidence Interval [CI] 1.054-1.167, p＜0.001) was independently associated with hemorrhage transformation. Systemic immune-inflammation index was found to be significantly related to hemorrhagic transformation in artery-to-artery embolization (OR 1.111, 95% CI 1.029-1.210, p＜0.001) and in-situ thrombosis (OR 1.059, 95% CI 1.011-1.194, p = 0.045).

CONCLUSIONS

Higher systemic immune-inflammation index is associated with greater risk of hemorrhagic transformation in patients with anterior circulation acute ischemic stroke due to large-artery atherosclerosis, especially in artery-to-artery embolization and in-situ thrombosis.

Prediction of Hemorrhagic Transformation After Ischemic Stroke: Development and Validation Study of a Novel Multi-biomarker Model

Objectives: We aimed to develop and validate a novel multi-biomarker model for predicting hemorrhagic transformation (HT) risk after acute ischemic stroke (AIS).

Methods: We prospectively included patients with AIS admitted within 24 h of stroke from January 1st 2016 to January 31st 2019. A panel of 17 circulating biomarkers was measured and analyzed in this cohort. We assessed the ability of individual circulating biomarkers and the combination of multiple biomarkers to predict any HT, symptomatic HT (sHT) and parenchymal hematoma (PH) after AIS. The strategy of multiple biomarkers in combination was then externally validated in an independent cohort of 288 Chinese patients.

Results: A total of 1207 patients with AIS (727 males; mean age, 67.2 ± 13.9 years) were included as a derivation cohort, of whom 179 patients (14.8%) developed HT. The final multi-biomarker model included three biomarkers [platelets, neutrophil-to-lymphocyte ratios (NLR), and high-density lipoprotein (HDL)] from different pathways, showing a good performance for predicting HT in both the derivation cohort (c statistic = 0·64, 95% CI 0·60–0·69), and validation cohort (c statistic = 0·70, 95% CI 0·58–0·82). Adding these three biomarkers simultaneously to the basic model with conventional risk factors improved the ability of HT reclassification [net reclassification improvement (NRI) 65.6%, P < 0.001], PH (NRI 64.7%, P < 0.001), and sHT (NRI 71.3%, P < 0.001).

Conclusion: This easily applied multi-biomarker model had a good performance for predicting HT in both the derivation and external validation cohorts. Incorporation of biomarkers into clinical decision making may help to identify patients at high risk of HT after AIS and warrants further consideration.

Hemorrhagic Transformation in Ischemic Stroke and the Role of Inflammation

Hemorrhagic transformation (HT) is a common complication in patients with acute ischemic stroke. It occurs when peripheral blood extravasates across a disrupted blood brain barrier (BBB) into the brain following ischemic stroke. Preventing HT is important as it worsens stroke outcome and increases mortality. Factors associated with increased risk of HT include stroke severity, reperfusion therapy (thrombolysis and thrombectomy), hypertension, hyperglycemia, and age. Inflammation and the immune system are important contributors to BBB disruption and HT and are associated with many of the risk factors for HT. In this review, we present the relationship of inflammation and immune activation to HT in the context of reperfusion therapy, hypertension, hyperglycemia, and age. Differences in inflammatory pathways relating to HT are discussed. The role of inflammation to stratify the risk of HT and therapies targeting the immune system to reduce the risk of HT are presented.

The 100 most-cited articles about the role of neurovascular unit in stroke 2001-2020: A bibliometric analysis

Background

The neurovascular unit (NVU) is emerging as a potential therapeutic target in neurological conditions, such as stroke, brain injury, Alzheimer's disease, and Parkinson's disease; meanwhile, stroke is the second leading cause of death globally. The purpose of the study is to analyze the most influential articles, authors, countries, and topics in the role of NVU in stroke.

Methods

The Web of Science (WoS) database was used for bibliometric analysis using the search terms “Stroke” and “Neurovascular unit” on January 1st, 2021. Data were extracted from the WoS database to identify collaborations between authors, countries, organizations, and keywords using VOSviewer (1.6.16 mac). Two bibliometric indicators, the activity index (AI) and category normalized citation impact (CNCI), were computed. The keywords of bursts were also identified by CiteSpace.

Results

A total of 770 articles were analyzed by VOSviewer. AIs and CNCIs were computed of the eighteen countries according to VOSviewer co‐authorship analysis results. The majority of authors mainly came from the United States and Japan. Romania, Hungary, and Poland have emerged as rising‐star countries. In the 100 most‐cited articles, the number of citations ranged from 1873 to 69, with a total of 15,758 citations. Most articles were published in 2011 and 2012 (n = 13 each), followed by 2009 (n = 11) and 2013, 2014, and 2015 (n = 8 each). Stroke and Journal of Cerebral Blood Flow and Metabolism were the two top journals. EH Lo from Harvard University/ Massachusetts General Hospital was the top first author and corresponding author. Harvard University/Massachusetts General Hospital was the most productive affiliated institution with 15 publications.

Conclusion

There has been growing attention and efforts made in the field of stroke and NVU. The merit of the above findings may help to shape the research policy in ischemic stroke both at the country and institutional level.

High fibrinogen-to-albumin ratio is associated with hemorrhagic transformation in acute ischemic stroke patients

INTRODUCTION

Hemorrhagic transformation (HT) is a complex and multifactorial complication among patients with acute ischemic stroke (AIS), and the inflammatory response has been considered as a risk factor for HT. We aimed to evaluate the stratification of FAR (fibrinogen-to-albumin ratio), an inflammatory biomarker, in HT patients.

METHODS

A total of 256 consecutive stroke patients with HT and 256 age- and gender-matched stroke patients without HT were included in this study. HT during hospitalization was diagnosed by follow-up imaging assessment and was classified into hemorrhagic infarction (HI) and parenchymal hematoma (PH) according to the recommendations of European Cooperative Acute Stroke Study II classification. Blood samples were obtained at admission.

RESULTS

Higher levels of FAR were observed in patients with HT compared with the non-HT group [10.29 (8.39-12.95) vs. 8.60 (7.25-10.8), p < .001], but no significant difference was found between the PH and HI [10.88 (8.72-13.40) vs. 10.13 (8.14-12.60), p > .05]. Patients were assigned to groups of high FAR (≥9.51) and low FAR (<9.51) based on the optimal cut-off value. After adjustment for potential confounders, the high FAR remained independently associated with the increased risk of HT (OR = 5.027, 95% CI = 5.027 (2.309-10.942), p < .001).

CONCLUSIONS

High FAR was independently associated with the increased risk of HT after AIS.

Osteopontin Predicts Three-Month Outcome in Stroke Patients Treated by Reperfusion Therapies

Establishing a prognosis at hospital admission after stroke is a major challenge. Inflammatory processes, hemostasis, vascular injury, and tissue remodeling are all involved in the early response to stroke. This study analyzes whether 22 selected biomarkers, sampled at admission, predict clinical outcomes in 153 stroke patients treated by thrombolysis and mechanical endovascular treatment (MET). Biomarkers were related to hemostasis (u-plasminogen activator/urokinase (uPA/urokinase), serpin E1/PAI-1, serpin C1/antithrombin-III, kallikrein 6/neurosin, alpha 2-macroglobulin), inflammation[myloperoxidase (MPO), chemokine ligand 2/monocyte chemoattractant protein-1 chemokine (CCL2/MCP-1), adiponectin, resistin, cell-free DNA (cDNA), CD40 Ligand (CD40L)], endothelium activation (Vascular cell adhesion protein 1 (VCAM-1) intercellular adhesion molecule 1 (ICAM-1), platelet endothelial cell adhesion molecule 1 (CD31/PECAM-1)], and tissue remodeling (total cathepsin S, osteopontin, cystatin C, neuropilin-1, matrix metallopeptidase 2 (MMP-2), matrix metallopeptidase 3 (MMP-3), matrix metallopeptidase 9 (MMP-9), matrix metallopeptidase 13 (MMP-13)]. Correlations between their levels and excellent neurological improvement (ENI) at 24 h and good outcomes (mRS 0-2) at three months were tested. Osteopontin and favorable outcomes reached the significance level (p = 0.008); the adjusted OR per SD increase in log-transformed osteopontin was 0.34 (95%CI, 0.18-0.62). The relationship between total cathepsin S and MPO with ENI, was borderline of significance (p = 0.064); the adjusted OR per SD increase in log-transformed of total cathepsin S and MPO was 0.54 (95%CI, 0.35-0.81) and 0.51 (95%CI, 0.32-0.80), respectively. In conclusion, osteopontin levels predicted three-month favorable outcomes, supporting the use of this biomarker as a complement of clinical and radiological parameters for predicting stroke prognosis.

Pathophysiology of Blood-Brain Barrier Permeability Throughout the Different Stages of Ischemic Stroke and Its Implication on Hemorrhagic Transformation and Recovery

The blood-brain barrier (BBB) is a dynamic interface responsible for maintaining the central nervous system homeostasis. Its unique characteristics allow protecting the brain from unwanted compounds, but its impairment is involved in a vast number of pathological conditions. Disruption of the BBB and increase in its permeability are key in the development of several neurological diseases and have been extensively studied in stroke. Ischemic stroke is the most prevalent type of stroke and is characterized by a myriad of pathological events triggered by an arterial occlusion that can eventually lead to fatal outcomes such as hemorrhagic transformation (HT). BBB permeability seems to follow a multiphasic pattern throughout the different stroke stages that have been associated with distinct biological substrates. In the hyperacute stage, sudden hypoxia damages the BBB, leading to cytotoxic edema and increased permeability; in the acute stage, the neuroinflammatory response aggravates the BBB injury, leading to higher permeability and a consequent risk of HT that can be motivated by reperfusion therapy; in the subacute stage (1-3 weeks), repair mechanisms take place, especially neoangiogenesis. Immature vessels show leaky BBB, but this permeability has been associated with improved clinical recovery. In the chronic stage (>6 weeks), an increase of BBB restoration factors leads the barrier to start decreasing its permeability. Nonetheless, permeability will persist to some degree several weeks after injury. Understanding the mechanisms behind BBB dysregulation and HT pathophysiology could potentially help guide acute stroke care decisions and the development of new therapeutic targets; however, effective translation into clinical practice is still lacking. In this review, we will address the different pathological and physiological repair mechanisms involved in BBB permeability through the different stages of ischemic stroke and their role in the development of HT and stroke recovery.

The presence of leukoaraiosis enhances the association between sTWEAK and hemorrhagic transformation

Objective

To investigate whether elevated serum levels of sTWEAK (soluble tumor necrosis factor‐like inducer of apoptosis) might be involved in a higher frequency of symptomatic hemorrhagic transformation (HT) through the presence of leukoaraiosis (LA) in patients with acute ischemic stroke (IS) undergoing reperfusion therapies.

Methods

This is a retrospective observational study. The primary endpoint was to study the sTWEAK‐LA‐HT relationship by comparing results with biomarkers associated to HT and evaluating functional outcome at 3‐months. Clinical factors, neuroimaging variables and biomarkers associated to inflammation, endothelial/atrial dysfunction or blood‐brain barrier damage were also investigated.

Results

We enrolled 875 patients (mean age 72.3 ± 12.2 years; 46.0% women); 710 individuals underwent intravenous thrombolysis, 87 endovascular therapy and 78 both. HT incidence was 32%; LA presence was 75.4%. Patients with poor functional outcome at 3‐months showed higher sTWEAK levels at admission (9844.2 [7460.4–12,542.0] vs. 2717.3 [1489.7–5852.3] pg/mL, P < 0.0001). By means of logistic regression models, PDGF‐CC and sTWEAK were associated with mechanisms linked simultaneously to HT and LA. Serum sTWEAK levels at admission ≥6700 pg/mL were associated with an odds ratio of 13 for poor outcome at 3‐months (OR: 13.6; CI 95%: 8.2–22.6, P < 0.0001).

Conclusions

Higher sTWEAK levels are independently associated with HT and poor functional outcome in patients with IS undergoing reperfusion therapies through the presence of LA. sTWEAK could become a therapeutic target to reduce HT incidence in patients with IS.

Lower uric acid level may be associated with hemorrhagic transformation but not functional outcomes in patients with anterior circulation acute ischemic stroke undergoing endovascular thrombectomy

To determine the correlation of uric acid (UA) with hemorrhagic transformation (HT) and poor short-term functional outcomes in anterior circulation acute ischemic stroke (AIS) patients after endovascular thrombectomy (EVT). A retrospective analysis was conducted for anterior circulation AIS patients who underwent EVT at our hospital from 2015 to 2019. HT within 72 h was documented according to the European Cooperative Acute Stroke Study II Classification. Baseline demographic, clinical and laboratory data were compared between the HT and non-HT groups, and between patients with favorable and unfavorable outcomes on 90-day. A total of 247 AIS patients were enrolled, of which 92 (37.2%) and 85 (34.4%) experienced HT and had favorable functional outcomes at 3 months respectively. Patients with HT had significantly lower UA levels compared to those without HT (322.60 ± 94.49 vs. 350.25 ± 99.28 μmol /L, P = 0.032). In contrast, UA levels were similar in patients with good or poor outcomes (345.67 ± 103.55 vs. 336.95 ± 95.5 μmol /L, P = 0.509). Compared to the patients with UA levels in the first quartile, those in the fourth quartile were at a higher risk of HT in univariate logistic regression analysis (OR = 0.383, 95% CI = 0.173-0.848, P = 0.018). The association remained significant after multivariable adjustment for potential confounders. A lower UA level is an independent risk factor of HT post-EVT in anterior circulation AIS patients, but is not associated with the short-term functional outcomes.

Comparison of the risk factors of hemorrhagic transformation between large artery atherosclerosis stroke and cardioembolism after intravenous thrombolysis

OBJECTIVE

Hemorrhagic transformation (HT) is a common complication of ischemic stroke after intravenous thrombolytic therapy (IVT), especially in cardioembolism (CE) and large artery atherosclerosis stroke (LAA) patients. Whether there are different risk factors for HT in LAA and CE patients remains unclear. The aim of this study was to explore the differences in risk factors for HT in patients with LAA and CE after IVT.

PATIENTS AND METHODS

A retrospective analysis was conducted on LAA and CE patients who were treated with intravenous tissue plasminogen activator at our hospital from 2015 to 2019. Demographic and clinical information was collected, and HT was evaluated within 72 h after stroke onset. Lipids levels, albumin, uric acid (UA), platelet volume indices, as well as potential predictors of HT were analyzed between patients with and without HT (non-HT group).

RESULTS

A total of 247 patients (168 LAA and 79 CE) were included in the study, out of which 62 (25.1 %) had HT. HT was more prevalent in the CE subgroup (30.3 %) than in the LAA subgroup (22.6 %). Compared with non-HT, patients with HT showed a higher rate of the previous stroke, baseline NIHSS scores, and mean platelet volume (MPV), lower levels of platelet count (PC), triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-C), albumin, and UA (P < 0.05). Multivariate logistic regression analysis showed that lower LDL (OR = 0.547, 95 % CI 0.321-0.932, P = 0.027), and higher blood glucose (OR = 1.137, 95 % CI 1.015-1.247, P = 0.026) were independent risk factors for HT in LAA patients, while lower albumin (OR = 0.989, 95 % CI 0.977-1.000, P = 0.048), and lower PC(OR = 0.868, 95 % CI 0.754-0.989, P = 0.047) were independent risk factors for HT in CE patients.

CONCLUSION

Patients with different etiologies may have different risk factors of HT following IVT. Lower LDL-C and higher blood glucose are independent risk factors of LAA, while lower albumin and PC are independent risk factors of CE.

Predictors of hemorrhagic transformation after acute ischemic stroke based on the experts' opinion

BACKGROUND

Hemorrhagic transformation (HT) is a common complication after ischemic stroke. It may be associated to poor outcomes. Some predictors of HT have been previously identified, but there remain controversies.

OBJECTIVE

To describe the risk factors for HT more frequently reported by a panel of experts surveyed for this project.

METHODS

We sent a standard questionnaire by e-mail to specialists in Vascular Neurology from 2014 to 2018. Forty-five specialists were contacted and 20 of them responded to the invitation. Predictors cited by three or more specialists were included in a table and ranked by the frequency in which they appeared. A review of the literature looking for published predictive scores of HT was performed, comparing to the answers received.

RESULTS

The 20 responding specialists cited 23 different risk factors for HT. The most frequent factors in the order of citation were the volume of ischemia, previous use of antithrombotic medication, neurological severity, age, hyperglycemia at presentation, hypertension on admission, and cardioembolism. Most variables were also found in previously published predictive scores, but they were reported by the authors with divergences of frequency.

CONCLUSION

Although many studies have evaluated HT in patients with acute ischemic stroke, the published risk factors were neither uniform nor in agreement with those cited by the stroke specialists. These findings may be helpful to build a score that can be tested with the goal of improving the prediction of HT.

High Neutrophil-to-Platelet Ratio Is Associated With Hemorrhagic Transformation in Patients With Acute Ischemic Stroke

Background: Hemorrhagic transformation (HT) is a complication that may cause neurological deterioration in patients with acute ischemic stroke. Both neutrophil and platelet have been associated with the stroke progression. The aim of this study was to explore the relationship between neutrophil-to-platelet ratio (NPR) and HT after acute ischemic stroke.

Methods: A total of 279 stroke patients with HT were consecutively recruited. HT was diagnosed using magnetic resonance imaging (MRI) or computed tomography (CT) and classified into hemorrhagic infarction (HI) and parenchymal hematoma (PH). Blood samples for neutrophil and platelet counts were obtained at admission. Meanwhile, 270 age- and gender-matched controls without HT were included for comparison.

Results: Among the patients with HT, 131 patients had PH and 148 patients had HI. NPR was higher in patients with PH than those with HI or non-HT [36.8 (23.7–49.2) vs. 26.6 (17.9–38.3) vs. 19.1 (14.8–24.8), P < 0.001]. After adjustment for potential confounders, high NPR remained independently associated with the increased risk of HT (OR = 2.000, 95% CI: 1.041–3.843, P = 0.037). NPR (>39.9) was independently associated with PH (OR = 2.641, 95% CI: 1.308–5.342, P = 0.007).

Conclusions: High NPR was associated with the increased risk of HT especially PH in patients with acute ischemic stroke.