Factors influencing hemorrhagic transformation in ischemic stroke: a clinicopathological comparison

Clinicopathological Observations in Acute Stroke Patients Treated with Intravenous Thrombolysis

Background: Ischemic stroke is a leading cause of mortality worldwide, and intravenous thrombolysis, while improving functional outcomes, still leaves a significant mortality rate. This study aimed to investigate the clinical and pathological data of thrombolysed stroke patients who subsequently died and underwent autopsy, focusing on hemorrhagic transformation (HT). Methods: Over a 10-year period, 1426 acute ischemic stroke patients received thrombolysis at our center, with an in-hospital mortality rate of 11.7%. Autopsies were performed on 98 of the 167 deceased patients. Results: HT was found in 47% of these cases, only less than half occurring within a day of thrombolysis. Significant independent predictors of HT included higher lactate dehydrogenase (LD) levels and higher INR values at admission. HT directly caused death in 30% of cases, often through herniation, while other complications (pulmonary embolism, pneumonia) were also common. Conclusions: These findings highlight the importance of postmortem investigations to accurately determine the incidence of HT and contributing factors. Our data indicate that in the vast majority of HT cases, the role of contributing factors other than rt-PA may be important. Of the routinely assessed clinical and laboratory parameters at admission, only LD and INR were found to be independent predictors of HT in the autopsied studied cohort.

Validation of a simple clinical tool for screening of acute lacunar stroke-A substudy of the WAKE-UP trial

INTRODUCTION

Lacunar stroke represents around a quarter of all ischemic strokes; however, their identification with computed tomography in the hyperacute setting is challenging. We aimed to validate a clinical score to identify lacunar stroke in the acute setting, independently, with data from the WAKE-UP trial using magnetic resonance imaging.

METHODS

We analyzed data from the WAKE-UP trial and extracted Oxfordshire Community Stroke Project (OCSP) classification. Lacunar score was defined by National Institutes of Health Stroke Scale (NIHSS) < 7 and OCSP lacunar syndrome. Assessment of lacunar infarct by two independent investigators was blinded to clinical data. We calculated sensitivity, specificity, negative and positive predictive value (NPV and PPV, respectively) of lacunar score.

RESULTS

We included 503 patients in the analysis, mean (±SD) age 65.2 (±11.6) years, 325 (65%) males, median (IQR) NIHSS = 6 (4-9); 108 (22%) lacunar infarcts were identified on magnetic resonance (MR), patients fulfilling lacunar score criteria were 120 (24%), of which 47 (44%) had a lacunar infarct. Lacunar score was negative in 322 (82%) of patients without lacunar infarct. Patients with lacunar score had lower NIHSS (4 vs 7, p < 0.001), higher systolic (157 vs 151 mmHg, p = 0.001) and diastolic (86 vs 83 mmHg, p = 0.013) blood pressure and smaller infarct volume (2.4 vs 9.5 mL, p < 0.001). Performance of lacunar score was as follows: sensitivity 0.44; specificity 0.82; PPV 0.39; NPV 0.84; and accuracy 0.73. Assuming a prevalence of lacunar stroke of 13%, PPV lowered to 0.30 but NPV was 0.90. Lacunar score performed better for supratentorial lacunar infarcts.

CONCLUSION

Lacunar score had a very good specificity and NPV for screening of lacunar stroke. Implementation of this simple tool into clinical practice may help hyperacute management and guide patient selection in clinical trials.

DATA ACCESS STATEMENT

Data supporting the results of this paper are available upon reasonable request to the corresponding author.

Radiomics using non-contrast CT to predict hemorrhagic transformation risk in stroke patients undergoing revascularization

OBJECTIVES

This study explores whether textural features from initial non-contrast CT scans of infarcted brain tissue are linked to hemorrhagic transformation susceptibility.

MATERIALS AND METHODS

Stroke patients undergoing thrombolysis or thrombectomy from Jan 2012 to Jan 2022 were analyzed retrospectively. Hemorrhagic transformation was defined using follow-up magnetic resonance imaging. A total of 94 radiomic features were extracted from the infarcted tissue on initial NCCT scans. Patients were divided into training and test sets (7:3 ratio). Two models were developed with fivefold cross-validation: one incorporating first-order and textural radiomic features, and another using only textural radiomic features. A clinical model was also constructed using logistic regression with clinical variables, and test set validation was performed.

RESULTS

Among 362 patients, 218 had hemorrhagic transformations. The LightGBM model with all radiomics features had the best performance, with an area under the receiver operating characteristic curve (AUROC) of 0.986 (95% confidence interval [CI], 0.971-1.000) on the test dataset. The ExtraTrees model performed best when textural features were employed, with an AUROC of 0.845 (95% CI, 0.774-0.916). Minimum, maximum, and ten percentile values were significant predictors of hemorrhagic transformation. The clinical model showed an AUROC of 0.544 (95% CI, 0.431-0.658). The performance of the radiomics models was significantly better than that of the clinical model on the test dataset (p < 0.001).

CONCLUSIONS

The radiomics model can predict hemorrhagic transformation using NCCT in stroke patients. Low Hounsfield unit was a strong predictor of hemorrhagic transformation, while textural features alone can predict hemorrhagic transformation.

CLINICAL RELEVANCE STATEMENT

Using radiomic features extracted from initial non-contrast computed tomography, early prediction of hemorrhagic transformation has the potential to improve patient care and outcomes by aiding in personalized treatment decision-making and early identification of at-risk patients.

KEY POINTS

• Predicting hemorrhagic transformation following thrombolysis in stroke is challenging since multiple factors are associated. • Radiomics features of infarcted tissue on initial non-contrast CT are associated with hemorrhagic transformation. • Textural features on non-contrast CT are associated with the frailty of the infarcted tissue.

Predictive Role of Pre-Thrombolytic Neutrophil-Platelet Ratio on Hemorrhagic Transformation After Intravenous Thrombolysis in Acute Ischemic Stroke

To investigate the predictive role of the neutrophil-platelet ratio (NPR) before intravenous thrombolysis (IVT) on hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS). AIS patients treated with IVT without endovascular therapy between June 2019 and February 2023 were included. Patients were divided into high NPR (>35) and low NPR (≤35) groups according to the optimal threshold NPR value for identifying high-risk patients before IVT. The baseline data and the incidence of HT and symptomatic intracranial hemorrhage (sICH) were compared between the two groups. The predictive role of the NPR and other related factors on HT after IVT was analyzed by multivariate logistic regression. A total of 247 patients were included, with an average age of 67.5 ± 12.4 years. Post-thrombolytic HT was observed in 18.6% of the patients, and post-thrombolytic sICH was observed in 1.2% of the patients. There were 69 patients in the high NPR group and 178 patients in the low NPR group. The incidence of HT in the high NPR group was significantly higher than that in the low NPR group (30.4% vs 16.3%, P < .05). The incidence of sICH was significantly higher in the high NPR group than in the low NPR group (14.5% vs 1.7%, P < .001). Multivariate logistic regression analysis showed that NPR > 35 was positively correlated with HT (odds ratio (OR) = 3.236, 95% confidence interval (CI): 1.481-7.068, P = .003) and sICH (OR = 13.644, 95% CI: 2.392-77.833, P = .003). A high NPR (>35) before IVT may be a predictor of HT in AIS patients. This finding may help clinicians make clinical decisions before IVT in AIS patients.

The early predictive value of platelet-to-lymphocyte ratio to hemorrhagic transformation of young acute ischemic stroke

Background

The increasing incidence of acute ischemic stroke (AIS) necessitates a comprehensive understanding of the related factors. Hemorrhagic transformation (HT), a severe complication of AIS, is influenced by platelet-induced inflammation and lymphocyte levels.

Objective

To measure the predictive value of platelet-to-lymphocyte ratio (PLR) in the occurrence of HT in young AIS patients.

Methods

Data of young AIS patients (n = 157) admitted to the hospital for the first time were retrospectively collected. The patients were divided into HT (63 patients) and non-HT groups (94 patients) on the basis of whether HT had occurred after admission. The National Institute of Health stroke scale (NIHSS) score was used to determine the severity of clinical symptoms. The relationship between PLR and HT and NIHSS scores was analyzed to evaluate the predictive value of PLR in the occurrence of HT using receiver operating characteristic (ROC) and area under the curve (AUC).

Results

Multivariate analysis showed that PLR and NIHSS are independent risk factors of HT. The PLR value of the observation group was positively associated with the NIHSS score (r = 0.8075, P < 0.0001). According to the PLR prediction about the occurrence of HT, an AUC of 0.713 (95% CI, 0.652-0.781), a cut-off value of 109.073, and a sensitivity and specificity of 0.806 and 0.674, respectively, were obtained.

Conclusions

PLR value can predict the possibility of HT in young AIS patients to a certain extent. To take effective measures to prevent HT in advance has crucial clinical significance according to PLR value.

Hemorrhagic Transformation of Ischemic Strokes

Ischemic stroke, resulting from insufficient blood supply to the brain, is among the leading causes of death and disability worldwide. A potentially severe complication of the disease itself or its treatment aiming to restore optimal blood flow is hemorrhagic transformation (HT) increasing morbidity and mortality. Detailed summaries can be found in the literature on the pathophysiological background of hemorrhagic transformation, the potential clinical risk factors increasing its chance, and the different biomarkers expected to help in its prediction and clinical outcome. Clinicopathological studies also contribute to the improvement in our knowledge of hemorrhagic transformation. We summarized the clinical risk factors of the hemorrhagic transformation of ischemic strokes in terms of risk reduction and collected the most promising biomarkers in the field. Also, auxiliary treatment options in reperfusion therapies have been reviewed and collected. We highlighted that the optimal timing of revascularization treatment for carefully selected patients and the individualized management of underlying diseases and comorbidities are pivotal. Another important conclusion is that a more intense clinical follow-up including serial cranial CTs for selected patients can be recommended, as clinicopathological investigations have shown HT to be much more common than clinically suspected.

The role of the blood-brain barrier during neurological disease and infection

A healthy brain is protected by the blood-brain barrier (BBB), which is formed by the endothelial cells that line brain capillaries. The BBB plays an extremely important role in supporting normal neuronal function by maintaining the homeostasis of the brain microenvironment and restricting pathogen and toxin entry to the brain. Dysfunction of this highly complex and regulated structure can be life threatening. BBB dysfunction is implicated in many neurological diseases such as stroke, Alzheimer's disease, multiple sclerosis, and brain infections. Among other mechanisms, inflammation and/or flow disturbances are major causes of BBB dysfunction in neurological infections and diseases. In particular, in ischaemic stroke, both inflammation and flow disturbances contribute to BBB disruption, leading to devastating consequences. While a transient or minor disruption to the barrier function could be tolerated, chronic or a total breach of the barrier can result in irreversible brain damage. It is worth noting that timing and extent of BBB disruption play an important role in the process of any repair of brain damage and treatment strategies. This review evaluates and summarises some of the latest research on the role of the BBB during neurological disease and infection with a focus on the effects of inflammation and flow disturbances on the BBB. The BBB's crucial role in protecting the brain is also the bottleneck in central nervous system drug development. Therefore, innovative strategies to carry therapeutics across the BBB and novel models to screen drugs, and to study the complex, overlapping mechanisms of BBB disruption are urgently needed.

S100b in acute ischemic stroke clots is a biomarker for post-thrombectomy intracranial hemorrhages

Background and purpose

Post-thrombectomy intracranial hemorrhages (PTIH) are dangerous complications of acute ischemic stroke (AIS) following mechanical thrombectomy. We aimed to investigate if S100b levels in AIS clots removed by mechanical thrombectomy correlated to increased risk of PTIH.

Methods

We analyzed 122 thrombi from 80 AIS patients in the RESTORE Registry of AIS clots, selecting an equal number of patients having been pre-treated or not with rtPA (40 each group). Within each subgroup, 20 patients had developed PTIH and 20 patients showed no signs of hemorrhage. Gross photos of each clot were taken and extracted clot area (ECA) was measured using ImageJ. Immunohistochemistry for S100b was performed and Orbit Image Analysis was used for quantification. Immunofluorescence was performed to investigate co-localization between S100b and T-lymphocytes, neutrophils and macrophages. Chi-square or Kruskal-Wallis test were used for statistical analysis.

Results

PTIH was associated with higher S100b levels in clots (0.33 [0.08-0.85] vs. 0.07 [0.02-0.27] mm², H1 = 6.021, P = 0.014^*), but S100b levels were not significantly affected by acute thrombolytic treatment (P = 0.386). PTIH was also associated with patients having higher NIHSS at admission (20.0 [17.0-23.0] vs. 14.0 [10.5-19.0], H1 = 8.006, P = 0.005) and higher number of passes during thrombectomy (2 [1-4] vs. 1 [1-2.5], H1 = 5.995, P = 0.014^*). S100b co-localized with neutrophils, macrophages and with T-lymphocytes in the clots.

Conclusions

Higher S100b expression in AIS clots, higher NIHSS at admission and higher number of passes during thrombectomy are all associated with PTIH. Further investigation of S100b expression in AIS clots by neutrophils, macrophages and T-lymphocytes could provide insight into the role of S100b in thromboinflammation.

Nomogram to predict haemorrhagic transformation after stroke thrombolysis: a combined brain imaging and clinical study

AIM

To construct a novel nomogram by integrating computed tomography perfusion (CTP) and clinical parameters for individualised prediction of haemorrhagic transformation (HT) in intravenous thrombolysis (IVT)-treated acute ischaemic stroke (AIS) patients.

METHODS

Anterior circulation AIS patients who underwent IVT at a single centre from January 2018 to June 2020 were reviewed retrospectively. The CTP parameters of two regions of interest (ROI), the entire perfusion lesion areas, and the infract core areas, were assessed. HT was documented by follow-up CT 24 ± 2 h after IVT. Multivariable logistic regression was conducted by including clinical variables and CTP parameters to identify the independent predictors of HT. A nomogram was developed based on the independent predictors. The discriminative value and calibration of the nomogram were tested by concordance indexes (C-indexes) and calibration plots. Internal validation was performed using fivefold cross-validation.

RESULTS

The nomogram was generated using the complete data from 341 patients. Seven variables were included in the final nomogram, including: the relative cerebral blood volume (rCBV), permeability surface (PS), and relative PS (rPS) in infract core areas, the relative time to maximum (rTmax) and rPS in entire perfusion lesion areas, the National Institutes of Health Stroke Scale (NIHSS), and atrial fibrillation (AF). The C-indexes were 0.815 and 0.817 for the nomogram and internal validation. The calibration plots showed excellent agreement.

CONCLUSION

This is the first study establishing a nomogram based on CTP and clinical parameters to predict HT after stroke thrombolysis.

IV-Thrombolysis in Ischemic Stroke With Unknown Time of Onset-Safety and Outcomes in Posterior vs. Anterior Circulation Stroke

Background: rt-PA for ischemic stroke in the unknown or extended time window beyond the first 4. 5 h after symptom onset is safe and effective for certain patients after selection by multimodal neuroimaging. However, the evidence for this approach comes mainly from patients with anterior circulation stroke (ACS), while the data on posterior circulation stroke (PCS) are scarce.

Methods: Ischemic stroke patients treated with IV-thrombolysis in the unknown or extended time window between January 2011 and May 2019 were identified from an institutional registry. The patients were categorized into PCS or ACS based on clinico-radiological findings. We analyzed the hemorrhagic complications, clinical and imaging efficacy outcomes, and mortality rates by comparing the PCS and ACS patient groups. Adjusted outcome analyses were performed after propensity score matching for the relevant factors.

Results: Of the 182 patients included, 38 (20.9%) had PCS and 144 (79.1%) had ACS. Symptomatic acute large vessel occlusion (LVO) was present in 123 patients on admission [27 (22.0%) PCS and 96 (78.0%) ACS]. The score on the National Institutes of Health Stroke Scale (NIHSS), the time from last seen normal, and the door-to-needle times were similar in PCS and ACS. In patients with LVO, the NIHSS score was lower [8 (5–15) vs. 14 (9–18), p = 0.005], and infarction visible on follow-up imaging was less common [70.4 vs. 87.5%; aRD, −18.9% (−39.8 to −2.2%)] in the PCS patient group. There was a trend toward a lower risk for intracranial hemorrhage (ICH) following intravenous thrombolysis in PCS vs. ACS, without reaching a statistical significance [5.3 vs. 16.9%; aRD, −10.4% (−20.4 to 4.0%)]. The incidence of symptomatic ICH [according to the ECASS III criteria: 2.6 vs. 3.5%; aRD, −2.9% (−10.3 to 9.2%)], efficacy outcomes, and mortality rates were similar in PCS and ACS patients.

Conclusions: In this real-world clinical cohort, the safety and the efficacy of rt-PA for ischemic stroke in the unknown or extended time window did not show relevant differences between PCS and ACS, with a trend toward less hemorrhagic complications in PCS. The findings reconfirm the clinician in the usage of rt-PA beyond the first 4.5 h also in selected patients with PCS.

Bleeding risk in patients with cardiac disease from ischaemic stroke reperfusion therapy: an update

Background

Intravenous tissue plasminogen activator (rtPA) and arterial endovascular therapy (ET) rapidly restore cerebral perfusion in eligible patients who had an acute ischaemic stroke (AIS). It is unknown whether patients who had an AIS with premorbid cardiac disease respond differently to reperfusion therapies than those without. These patients may have risk factors that worsen outcomes or may represent those who would most benefit from reperfusion therapy.

Objective

To determine whether patients who had an AIS with the most frequently encountered pre-existing cardiac conditions, atrial fibrillation (AF), heart failure (HF), left ventricular assist devices (LVADs), or taking anticoagulation for cardiac indications, are at increased risk for poor outcome, such as symptomatic intracranial haemorrhage (sICH), after reperfusion therapy.

Results

Although AF is an independent risk factor for poor poststroke outcomes, intravenous rtPA is not associated with increased risk of sICH for those not on anticoagulants. Likewise, HF is independently associated with mortality post stroke, yet these patients benefit from reperfusion therapies without increased rates of sICH. Patients with LVADs or who are on anticoagulation should not be given IV rtPA; however, ET remains a viable option in those who meet criteria, even patients with LVAD.

Conclusion

There is no evidence of an increased risk for sICH after intravenous rtPA or ET for those with AF or HF. Intravenous rtPA should not be given to patients on anticoagulation or with LVADs, but ET should be offered to them when eligible. Whenever possible, future AIS reperfusion research should include patients with premorbid cardiac disease as they are frequently excluded, representing a gap in evidence.

The Osteoporotic Condition as a Predictive Factor for Hemorrhagic Transformation in Acute Cardioembolic Stroke

Objective

Hemorrhagic transformation (HT) can be occurred after acute cerebral infarction. HT can worse symptoms in severe cases and adversely affect long-term prognosis. As bone and vascular smooth muscle are composed of type 1 collagen, we aimed to identify a potential relationship between bone mineral density (BMD) and HT after acute cardioembolic stroke.

Methods

As an indicator of BMD, we used mean frontal skull Hounsfield unit (HU) values on brain computed tomography (CT). Multivariative hazard ratios were calculated using Cox regression analysis to identify whether the osteoporotic condition was an independent predictor of HT after acute cardioembolic stroke.

Results

This 11-year analysis enrolled 506 patients who diagnosed as acute cardioembolic infarction. The first tertile of skull HU value was an independent predictor of HT development compared to the third tertile (hazard ratio, 2.12; 95% confidence interval, 1.13–3.98; p=0.020). We observed no interactions between age and skull HU with respect to HT statistically.

Conclusion

The results of this study revealed an association between osteoporotic conditions and HT development after acute cardioembolic stroke. A convenient method to measure the cancellous bone HU value of the frontal skull using brain CT images may be useful for predicting HT in patients with acute cerebral infarction.

Extent of white matter lesion is associated with early hemorrhagic transformation in acute ischemic stroke related to atrial fibrillation

BACKGROUND

Hemorrhagic transformation (HT) after stroke, related to atrial fibrillation (AF), is a frequent complication, and it can be associated with a delay in the (re-)initiation of oral anticoagulation therapy. We investigated the effect of the presence and severity of white matter disease (WMD) on early HT after stroke related to AF.

METHODS

A consecutive series of patients with recent (<4 weeks) ischemic stroke and AF, treated at the Hyper Acute Stroke Unit of the Imperial College London between 2010 and 2017, were enrolled. Patients with brain MRI performed 24-72 h from stroke onset and not yet started on anticoagulant treatment were included. WMD was graded using the Fazekas score.

RESULTS

Among the 441 patients eligible for the analysis, 91 (20.6%) had any HT. Patients with and without HT showed similar clinical characteristics. Patients with HT had a larger diffusion-weighted imaging (DWI) infarct volume compared to patients without HT (p < .001) and significant difference in the distribution of the Fazekas score (p = .001). On multivariable analysis, HT was independently associated with increasing DWI infarct volume (odd ratio (OR), 1.03; 95% confidence interval (CI), 1.01-1.05; p < .001), higher Fazekas scores (OR, 1.94; 95% CI, 1.47-2.57; p < .001) and history of previous intracranial hemorrhage (OR, 4.80; 95% CI, 1.11-20.80; p = .036).

CONCLUSIONS

Presence and severity of WMD is associated with increased risk of development of early HT in patients with stroke and AF. Further evidence is needed to provide reliable radiological predictors of the risk of HT in cardioembolic stroke.

High Chloride Burden and Clinical Outcomes in Critically Ill Patients With Large Hemispheric Infarction

Background: In general, disease severity has been found to be associated with abnormal chloride levels in critically ill patients, but hyperchloremia is associated with mixed results regarding patient-centered clinical outcomes. We aimed to investigate the impact of maximum serum chloride concentration on the clinical outcomes of critically ill patients with large hemispheric infarction (LHI).

Methods: We conducted a retrospective observational cohort study using prospective institutional neurocritical care registry data from 2013 to 2018. Patients with LHIs involving over two-thirds of middle cerebral artery territory, with or without infarction of other vascular territories, and a baseline National Institutes of Health Stroke Scale score of ≥13 were assessed. Those with a baseline creatinine clearance of <15 mL/min and required neurocritical care for <72 h were excluded. Primary outcome was in-hospital mortality. Secondary outcomes included 3-month mortality and acute kidney injury (AKI) occurrence. Outcomes were compared to different maximum serum chloride levels (5 mmol/L increases) during the entire hospitalization period using multivariable logistic regression analyses.

Results: Of 90 patients, 20 (22.2%) died in-hospital. Patients who died in-hospital had significantly higher maximum serum chloride levels than did those who survived up to hospital discharge (139.7 ± 8.1 vs. 119.1 ± 10.4 mmol/L; p < 0.001). After adjusting for age, sex, and Glasgow coma scale score, each 5-mmol/L increase in maximum serum chloride concentration was independently associated with an increased risk of in-hospital mortality (adjusted odds ratio (aOR), 4.34; 95% confidence interval [CI], 1.98–9.50; p < 0.001). Maximum serum chloride level was also an independent risk factor for 3-month mortality (aOR, 1.99 [per 5 mmol/L increase]; 95% CI, 1.42–2.79; p < 0.001) and AKI occurrence (aOR, 1.57 [per 5 mmol/L increase]; 95% CI, 1.18–2.08; p = 0.002).

Conclusions: High maximum serum chloride concentrations were associated with poor clinical outcomes in critically ill patients with LHI. This study highlights the importance of monitoring serum chloride levels and avoiding hyperchloremia in this patient population.

Astrocyte Activation in Neurovascular Damage and Repair Following Ischaemic Stroke

Transient or permanent loss of tissue perfusion due to ischaemic stroke can lead to damage to the neurovasculature, and disrupt brain homeostasis, causing long-term motor and cognitive deficits. Despite promising pre-clinical studies, clinically approved neuroprotective therapies are lacking. Most studies have focused on neurons while ignoring the important roles of other cells of the neurovascular unit, such as astrocytes and pericytes. Astrocytes are important for the development and maintenance of the blood-brain barrier, brain homeostasis, structural support, control of cerebral blood flow and secretion of neuroprotective factors. Emerging data suggest that astrocyte activation exerts both beneficial and detrimental effects following ischaemic stroke. Activated astrocytes provide neuroprotection and contribute to neurorestoration, but also secrete inflammatory modulators, leading to aggravation of the ischaemic lesion. Astrocytes are more resistant than other cell types to stroke pathology, and exert a regulative effect in response to ischaemia. These roles of astrocytes following ischaemic stroke remain incompletely understood, though they represent an appealing target for neurovascular protection following stroke. In this review, we summarise the astrocytic contributions to neurovascular damage and repair following ischaemic stroke, and explore mechanisms of neuroprotection that promote revascularisation and neurorestoration, which may be targeted for developing novel therapies for ischaemic stroke.

Automated estimation of ischemic core prior to thrombectomy: comparison of two current algorithms

PURPOSE

Endovascular thrombectomy (EVT) improves clinical outcomes in ischemic stroke with large vessel occlusion. Clinical benefits are inversely proportional to size of the pre-treatment ischemic core. This study compared estimated ischemic core volumes by two different CT perfusion (CTP) automated algorithms to the gold standard follow-up infarct volume using diffusion-weighted imaging (DWI) to assess for congruence, and thus eligibility for EVT.

METHODS

Retrospective, single-center cohort study of 102 patients presenting to a comprehensive stroke center between 2012 and 2018. Inclusion criteria were CT perfusion prior to EVT, successful EVT with mTIBI 2b-3 reperfusion, and DWI post-EVT. CTP data were retrospectively processed by two algorithms: "delay and dispersion insensitive deconvolution" (DISD, RAPID software) versus "delay and dispersion corrected single value decomposition" (ddSVD, Mistar software), using commercially available software. Core volumes were compared to follow up DWI using independent software (MRIcron). Agreement between each algorithm and DWI was estimated using Lin's concordance coefficient and analyzed using reduced major axis regression.

RESULTS

We included 102 patients. Both algorithms had excellent agreement with DWI (Lin's concordance coefficients: DISD 0.8 (95% CI: 0.73; 0.87), ddSVD 0.92 (95% CI: 0.89; 0.95). Compared to ddSVD (reduced major axis slope = 0.95), DISD exhibited a larger extent of proportional bias (slope = 1.12).

CONCLUSION

The ddSVD algorithm better correlates with DWI follow-up infarct volume than DISD processing. The DISD algorithm overestimated larger ischemic cores which may lead to patient exclusion from thrombectomy based on selection by core volume.

Serum Interleukin-33 is a Novel Predictive Biomarker of Hemorrhage Transformation and Outcome in Acute Ischemic Stroke

INTRODUCTION

Hemorrhage Transformation (HT) in acute ischemic stroke (AIS) depends on multiple factors. Some studies have shown that serum interleukin-33 (IL-33) is of central significance as a neuroprotective factor. However, the relationship between serum IL-33 and HT in AIS has not been evaluated.

OBJECTIVE

To investigate the relationship between serum IL-33 concentration and HT in AIS.

METHODS

We recruited 151 consecutive non-thrombolytic patients with AIS clinically diagnosed in The First Affiliated Hospital of Chongqing Medical University from December 2018 to October 2019. If the patients showed radiographic presentation of HT within two weeks following admission, they were assigned to the HT group; others were assigned to the non-HT group. There were 40 healthy control subjects recruited during the same period. Serum IL-33 concentration was detected by ELISA and the independent risk value of HT in AIS was predicted by multivariate logistic regression. The accuracy was analyzed by receiver operating characteristic (ROC) curves. In three months after admission, the functional outcome was measured by modified Rankin scale (mRS).

RESULTS

ROC curve showed that the area under the curve (AUC) of serum IL-33 was 0.739 (95% CI: 0.657-0.821, P < .001) in predicting HT in AIS. When serum IL-33 concentration was ≤ 67.66 ng/L, the sensitivity and specificity of the prediction were 81.3% and 63%, respectively. Multivariate logistic regression analysis showed that serum IL-33 concentration ≤ 67.66 ng/L was an independent predictor of HT in AIS (OR = 5.773, 95% CI: 1.685-19.792, P = .005). The follow-up results of mRS showed a higher probability of an unfavorable outcome in those with HT compared to those without HT (OR = 6.520, 95% CI: 2.530-16.803, P < .001).

CONCLUSIONS

HT in AIS is negatively correlated with outcome. Furthermore, serum IL-33 is an independent predictive biomarker of HT and outcome in AIS.

Clinical Characteristics and Outcome of Patients With Hemorrhagic Transformation After Intravenous Thrombolysis in the WAKE-UP Trial

Background: Hemorrhagic transformation (HT) is an important complication of intravenous thrombolysis with alteplase. HT can show a wide range from petechiae to parenchymal hematoma with mass effect with varying clinical impact. We studied clinical and imaging characteristics of patients with HT and evaluated whether different types of HT are associated with functional outcome.

Methods: We performed a post-hoc analysis of WAKE-UP, a multicenter, randomized, placebo-controlled trial of MRI-guided intravenous alteplase in unknown onset stroke. HT was assessed on follow-up MRI or CT and diagnosed as hemorrhagic infarction type 1 and type 2 (HI1 and HI2, combined as HI), and parenchymal hemorrhage type 1 and type 2 (PH1 and PH2, combined as PH). Severity of stroke symptoms was assessed using the National Institutes of Health Stroke Scale (NIHSS) at baseline. Stroke lesion volume was measured on baseline diffusion weighted imaging (DWI). Primary endpoint was a favorable outcome defined as a modified Rankin Scale score 0–1 at 90 days.

Results: Of 483 patients included in the analysis, 95 (19.7%) showed HI and 21 (4.4%) had PH. Multiple logistic regression analysis identified treatment with alteplase (OR, 2.08 [95% CI, 1.28–3.40]), baseline NIHSS score (OR, 1.11 [95% CI, 1.05–1.17]), DWI lesion volume (OR, 1.03 [95% CI, 1.01–1.05]), baseline glucose levels (OR, 1.01 [95% CI, 1.00–1.01]) and atrial fibrillation (OR, 3.02 [95% CI, 1.57–5.80]) as predictors of any HT. The same parameters predicted HI. Predictors of PH were baseline NIHSS score (OR, 1.11 [95% CI, 1.01–1.22]) and as a trend treatment with alteplase (OR, 2.40 [95% CI, 0.93–6.96]). PH was associated with lower odds of favorable outcome (OR 0.25, 95% [CI 0.05–0.86]), while HI was not.

Conclusion: Our results indicate that HI is associated with stroke severity, cardiovascular risk factors and thrombolysis. PH is a rare complication, more frequent in severe stroke and with thrombolysis. In contrast to HI, PH is associated with worse functional outcome. The impact of HT after MRI-guided intravenous alteplase for unknown onset stroke on clinical outcome is similar as in the trials of stroke thrombolysis within a known early time-window.

Low triglyceride to high-density lipoprotein cholesterol ratio predicts hemorrhagic transformation in large atherosclerotic infarction of acute ischemic stroke

The ratio of triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) is an objective approach to predicting poor outcomes in acute ischemic stroke (AIS). The impact of TG/HDL-C on hemorrhagic transformation (HT) after AIS remains unknown. The aim of this study was to explore the accurate effect of TG/HDL-C on HT after AIS. We enrolled a total of 1423 patients with AIS in the training cohort from a prospective, consecutive hospital-based stroke registry. Of the 1423 patients, HT occurred in 155 (10.89%) patients. The incidence of HT after AIS was significantly increased when there were low levels of TG (P=0.016) and TG/HDL-C (P=0.006) in patients with AIS attributable to large artery atherosclerosis (LAA), but not in those who suffered from cardioembolic stroke. After adjustment for covariates, a lower TG/HDL-C (OR=0.53, 95%CI=0.20-0.93) that was more than TG alone (OR=0.61, 95%CI=0.27-0.98) independently increased the risk of HT in LAA. Furthermore, our established nomogram indicated that lower TG/HDL-C was an indicator of HT. These findings were further validated in the test cohort of 558 patients with AIS attributable to LAA. In summary, a low level of TG/HDL-C is correlated with greater risk of HT after AIS attributable to LAA.

Increased microvascular permeability and low level of low-density lipoprotein cholesterol predict symptomatic intracerebral hemorrhage in acute ischemic stroke

Symptomatic intracerebral hemorrhage is a serious potential complication of recombinant tissue-type plasminogen activator thrombolysis in acute ischemic stroke. We investigated the optimal imaging and clinical parameters to predict symptomatic intracerebral hemorrhage in acute ischemic stroke patients after recombinant tissue-type plasminogen activator therapy. We retrospectively reviewed 151 acute ischemic stroke patients with thrombolytic therapy, who were dichotomized into symptomatic intracerebral hemorrhage group and non-symptomatic intracerebral hemorrhage group. They underwent multimodal computed tomography, including the measurement of permeability surface. We compared the clinical and radiological characteristics between symptomatic intracerebral hemorrhage group and non-symptomatic intracerebral hemorrhage group, using univariate analysis. Receiver operating characteristic analysis and multivariate logistic regression analyses were then used to determine symptomatic intracerebral hemorrhage predictors. Of 151 patients, 14 patients (9.27%) developed symptomatic intracerebral hemorrhage on follow-up imaging. Relative permeability surface (infarct permeability surface/contralateral normal permeability surface) (p < 0.05) and baseline low-density lipoprotein cholesterol level (p < 0.05) were both predictors of symptomatic intracerebral hemorrhage. Receiver operating characteristic analysis of relative permeability surface revealed an optimal relative permeability surface threshold of 2.239, with an area under the curve of 0.87 (95% confidence interval, 0.732-1.0). The relative permeability surface was 2.239, the sensitivity for symptomatic intracerebral hemorrhage was 85.7%, the specificity was 94.9%, the positive predictive value was 70.6%, and the negative predictive value was 95.5%. For low-density lipoprotein cholesterol, the optimal threshold was 2.45, with an area under the curve of 0.726 (95% confidence interval, 0.586-0.867), the sensitivity for symptomatic intracerebral hemorrhage was 73.0%, the specificity was 64.3%, the positive predictive value was 67.16%, and the negative predictive value was 79.09%. Our study demonstrated that increased infarct permeability surface and low level of low-density lipoprotein cholesterol can be two predictors of symptomatic intracerebral hemorrhage. Detection of relative permeability surface and low-density lipoprotein cholesterol may help clinicians to identify acute ischemic stroke patients with the higher risk of symptomatic intracerebral hemorrhage; intravenous thrombolytic therapy should be carefully performed for patients with high relative permeability surface and low low-density lipoprotein cholesterol. We may take relative permeability surface and low-density lipoprotein cholesterol into account to refine therapeutic decision-making in acute ischemic stroke.

Predicting hemorrhagic transformation and its timing from maximum cerebral lesion diameter in nonlacunar ischemic strokes

OBJECTIVES

We performed this retrospective cohort study to establish which factors are mostly indicative of the appearance of hemorrhagic transformation (HT) and of its time course in a sample of nonlacunar ischemic strokes.

MATERIALS AND METHODS

In 402 patients with nonlacunar ischemic stroke (75.0 ± 12.7 years, 192 male), clinical, laboratory, and neuroimaging variables obtained during the first 3 days of hospitalization were compared between patients with and without HT at computer tomography scan.

RESULTS

HT was documented in 129 patients (32.1%), including 36 with parenchymal hematoma (PH), after a median time of 6 days (range 1-27). Many variables were univariately associated with HT, but only 5 of them were confirmed in Cox regression (Hazard Ratio, 95% Confidence Interval): maximum cerebral lesion diameter (CLD) in cm (1.12, 1.06-1.18; p = .0001), hemoglobin in g/dl (1.16, 1.06-1.27; p = .002), blood glucose in mmol/L (1.10, 1.03-1.18; p = .007), prior anticoagulant therapy (1.82, 1.10-3.03; p = .02), and edema with mass effect (1.72, 1.08-2.75; p = .02). Thus, the most significant predictor was CLD. The overall risk of HT was minimum for CLD < 2 cm (1.5%), intermediate for CLD ≥ 2 and < 5 cm (22%), and maximum for CLD ≥ 5 cm (58%). The residual probability of having HT decreased progressively over time, and a simple formula is proposed to predict, from CLD in cm, when the probability of HT falls below 10%.

CONCLUSIONS

The main determinant of HT was CLD, a simple quantitative parameter that could prove useful, in particular, in deciding the timing of anticoagulation in cardioembolic stroke patients.

There Is No Association Between the Number of Stent Retriever Passes and the Incidence of Hemorrhagic Transformation for Patients Undergoing Mechanical Thrombectomy

Background: Previous research has focused on the association between hemorrhagic transformation (HT) incidence and pre-procedural variables (i.e., baseline variables) rather than the association between HT incidence and endovascular treatment (EVT) procedural variables (e.g., stent retriever passes).

Objective: To assess the association, if any, that exists between the number of stent retriever passes per procedure and the incidence of HT for patients undergoing mechanical thrombectomy.

Methods: An endovascular database from a comprehensive stroke center was used to collect data on EVT patients treated with Trevo, Solitaire, or Penumbra stent retrievers from the years 2012 to 2017. Statistical analyses were conducted on the stent retriever passes, demographics, morbidities, medication usage, and outcomes and their association with HT.

Results: Of the 329 total patients, 46 (14%) had HT. The HT group had an average [SD] of 1.65 [0.67] and range of [1–3] passes per procedure while the non-HT group had an average [SD] of 1.63 [0.86] and range of [1–5] passes per procedure. Admission NIHSS score (p = 0.0003) and the incidence of diabetes mellitus (DM) (p = 0.05) were significantly higher in the HT group. Subdividing HT into symptomatic and asymptomatic ICH groups failed to display significant differences in the distribution of the stent retriever passes (p = 0.969). The number of passes failed to show any association with HT (p = 0.804) while admission NIHSS score was found to have an OR of 1.07 (95%CI: 1.029–1.121, p = 0.001) with HT incidence.

Conclusion: No significant association was found between HT incidence and the stent retriever passes. Further multicenter studies are warranted to corroborate our results.

Glomerular Filtration Rate is Associated with Hemorrhagic Transformation in Acute Ischemic Stroke Patients without Thrombolytic Therapy

Background:

Whether there is a relationship between glomerular filtration rate (GFR) and hemorrhagic transformation (HT) after acute ischemic stroke (AIS) is still under debate. The aim of our study was to determine whether the GFR level is a predictor of HT in AIS patients without thrombolytic therapy (TT).

Methods:

Consecutive AIS patients without TT were included in this prospective study from January 2014 to December 2016 in the First Affiliated Hospital of Chongqing Medical University. We divided them into two groups (HT and non-HT group) and meticulously collected baseline characteristics and laboratory and imaging data of interested individuals. Multivariate regression analysis was performed to assess the correlation between GFR and HT in stroke patients without TT.

Results:

Among 426 consecutive patients, 74 (17.3%) presented HT (mean age: 65 ± 12 years, number of male patients: 47) on the follow-up scans. In multivariate regression analysis, HT was significantly associated with low GFR (odds ratio [OR] = 3.708, confidence interval [CI] = 1.326–10.693, P = 0.013), atrial fibrillation (AF; OR = 2.444, CI = 1.087–5.356, P = 0.027), large cerebral infarction (OR = 2.583, CI = 1.236–5.262, P = 0.010), and hypoalbuminemia (HA; OR = 4.814, CI = 1.054–22.153, P = 0.037) for AIS patients without TT.

Conclusions:

The present study strongly showed that lower GFR is an independently predictor of HT; in addition, large infarct volume, AF, and HA are also important risks of HT for AIS patients without TT, which offered a practical information that risk factors should be paid attention or eliminated to prevent HT for stroke patients though the level of evidence seems to be unstable.

Cerebral Microbleeds in an Acute Ischemic Stroke as a Predictor of Hemorrhagic Transformation

Background

Cerebral microbleeds are small, round hypointensities of <10 mm in diameter, evident on T2* gradient-recall echo (GRE) or susceptibility-weighted (SWI) magnetic resonance imaging (MRI) sequences.

Objective

In this study, our objective was to determine the number and location of cerebral microbleeds in ischemic stroke and to identify the predictive role of microbleeds for hemorrhagic transformation.

Materials and methods

This was a retrospective cohort study. Microbleeds were visually rated on SWI scans of patients who presented with an ischemic stroke and had an SWI scan within 24 hours of onset and a computed tomography (CT)/MRI scan during follow up. Microbleeds were graded as Grades I-IV.

Results

Out of 575 stroke patients, 121 did not have an SWI scan and 336 had no follow-up scan. A total of 118 patients were included for a final analysis (75 males, 43 females) out of which 30 had a hemorrhagic transformation. Most microbleeds were in the parietal region (n=46) with 50% transformation (p-value <0.001). The size and grade of microbleeds had a statistical association with hemorrhagic transformation with p-value 0.001 and p-value <0.001, respectively; 33% of patients with Grade 3 microbleeds aging 55-65 years had transformations. Of the patients, 93.3% with Grade 4 microbleeds had a hemorrhagic transformation. 30% of transformations were detected in the first 24 hours while 30% were detected during the first week. Age, gender, comorbidity, and anticoagulant use had no statistical association of conversion of microbleeds into hemorrhagic transformation.

Conclusion

Microbleeds detected on an SWI scan is a relevant and accurate predictor of hemorrhagic transformations in acute ischemic infarcts and should be added to MRI stroke protocols.

Computed Tomography Perfusion Alberta Stroke Program Early Computed Tomography Score Is Associated with Hemorrhagic Transformation after Acute Cardioembolic Stroke

Alberta Stroke Program Early Computed Tomography (CT) score (ASPECTS) has been applied to CT perfusion (CTP) with good interrater agreement to predict early ischemic stroke, and it can be useful in decision making in acute ischemic stroke. The aim of the present study was to assess the predictive value of CTP ASPECTS of hemorrhagic transformation (HT) in acute cardioembolic stroke. This is a single-enter, retrospective study. All patients hospitalized with acute cardioembolic stroke from January 2008 to September 2013 were included. ASPECTS of baseline non-contrast CT, CTP maps of cerebral blood volume (CBV), cerebral blood flow, and mean transit time were collected from 52 consecutive patients with less than 12-h anterior circulation ischemic stroke. MRI scan was performed within 72 h of symptom onset after index stroke including T2*-weighted gradient echo to identify HT. For bleeding risk assessment, CTP and diffusion-weighted imaging ASPECTS were categorized into 0–7 or 8–10. Baseline characteristics, ASPCETS scores and HT were compared. Eighteen (34.6%) patients had HT and four (7.7%) developed symptomatic HT. On univariate analysis, the proportion of patients with CBV-ASPECTS 0–7 was significantly higher in HT patients as compared to patients without HT (44 versus 9%, P = 0.005). CBV ASPECTS 0–7 remained independent prognostic factors for HT after adjustment for clinical baseline variables. CBV ASPECTS could be of value to predict HT risk after acute cardioembolic stroke and may be a quick risk assessment approach before reperfusion therapy.

Haemorrhagic transformation in ischaemic stroke is more frequent than clinically suspected - A neuropathological study

OBJECTIVES

The vast majority of literature on the frequency of the haemorrhagic transformation of ischaemic stroke is based on imaging studies. The purpose of the present study was to assess the added value of autopsy and neuropathological analysis in a neurology centre with emphasis on acute stroke care.

METHODS

We retrospectively analysed the findings of 100 consecutive brain autopsies followed by detailed clinical correlation.

RESULTS

The clinical diagnosis was confirmed by neuropathology in every patient with intracerebral haemorrhage and with non-cerebrovascular neurological disorders (e.g. primary tumours, metastases, infections). At admission 64 patients (age 62years, SD 6.5) were diagnosed with acute ischaemic stroke. In 10 of these patients (16%) haemorrhagic transformation was diagnosed clinically by a second CT. In 24 cases (38%) haemorrhagic transformation was detected only at autopsy. The distribution of haemorrhagic transformation in our material was the following: small petechiae in 26.5%, more confluent petechiae in 29.4%, ≤30% of the infarcted area with some mild space-occupying effect in 29.4% and >30% of the infarcted area with significant space-occupying effect or clot remote from infarcted area in 14.7%. Most of the PH1-2 transformations developed in thrombolysed patients and all of the PH2 type transformations were diagnosed already clinically.

CONCLUSIONS

We demonstrated that haemorrhagic transformation is frequent and often undiscovered in vivo. Our findings underline the importance of post-mortem neuropathological examination also in the era of advanced imaging techniques and prove that autopsy is the ultimate yardstick of our diagnostic and therapeutic efforts. The high number of haemorrhagic transformations diagnosed only after death is an important novel finding with clinical implications.

Risk Factors for Hemorrhagic Transformation in Patients with Acute Middle Cerebral Artery Infarction

INTRODUCTION

Hemorrhagic transformation (HT) after acute ischemic stroke (AIS) can be seen at any time following ischemic stroke. Although HT usually occurs as a complication of antithrombotic, anticoagulant, or thrombolytic treatments, it can also occur spontaneously. We aimed to investigate the occurrence of early HT and its relevant risk factors in patients diagnosed with acute middle cerebral artery (MCA) infarction who were not treated with thrombolytic agents.

METHODS

We recruited 171 patients with acute MCA infarction between January 2011 and July 2012 who were not treated with thrombolytic agents and were suitable to our inclusion criteria. Controlled neuroimaging was performed immediately in patients with deterioration, otherwise on day 7 following stroke. All patients were investigated for AIS risk factors and biochemical analyses were performed. Patients with HT in controlled neuroimaging were grouped both clinically (i.e., symptomatic or asymptomatic) and radiologically, according to "European Cooperative Acute Stroke Radiological Study" (ECASS), and risk factors were examined.

RESULTS

We enrolled 171 patients [94 men (55%) and 77 women (45%)] in the study. HT developed in 37 patients (21.63%). In terms of risk factor analysis, the most frequent etiological factor was atherosclerosis in AIS patients (50.3%). National Institutes of Health Stroke Scale scores were significantly higher both in sHT patients according to asHT patients and in HT patients on day 7 compared with their initial scores. Serum low-density lipoprotein (LDL-C), triglycerides (TG), and total cholesterol (TC) levels were significantly lower in patients with HT (p<.001).

CONCLUSION

HT is a major complication in AIS that considerably increases the morbidity and mortality. To reduce the occurrence of HT, risk factors for each patient population should be determined. Acute thrombolytic therapy should be used cautiously in high-risk patients, and appropriate alternative therapies should be revised in them.

Thrombolytic-Related Asymptomatic Hemorrhagic Transformation Does Not Deteriorate Clinical Outcome: Data from TIMS in China

OBJECTIVE

It has been unclear whether thrombolytic-related asymptomatic hemorrhagic transformation (AHT) affects the clinical outcome. To answer this question, we examined whether thrombolytic-related AHT affect short-term and long-term clinical outcome.

METHODS

All data were collected from the Thrombolysis Implementation and Monitor of Acute Ischemic Stroke in China (TIMS-China) registry. The patients were diagnosed as having AHT group and non- hemorrhagic transformation (HT) group based on clinical and imaging data. The patients with symptomatic hemorrhagic transformation were excluded from this study. Thrombolytic-related AHT was defined according to European-Australasian Acute Stroke Study (ECASS) II criteria. 90-day functional outcome, 7-day National Institutes of Health Stroke Scale (NIHSS) score, 7-day and 90-day mortalities were compared between two groups. Logistic regression analysis was used to evaluate the effects of AHT on a short-term and long-term clinical outcome.

RESULTS

904 of all 1440 patients in TIMS-China registry were enrolled. 89 (9.6%) patients presented with AHT after thrombolysis within 24-36 h. These patients with AHT were more likely to be elder age, cardioembolic subtype, and to have higher National Institutes of Health Stroke Scale score before thrombolysis than patients without AHT. No significant difference was found on the odds of 7-day (95% CI:0.692 (0.218-2.195), (P = 0.532) or 90-day mortalities (95% CI:0.548 (0.237-1.268), P = 0.160) and modified Rankin Score(0-1) at 90-day (95% CI:0.798 (0.460-1.386), P = 0.423) or modified Rankin Score(0-2) at 90-day (95% CI:0.732 (0.429-1.253), P = 0.116) or modified Rankin Score(5-6) at 90-day (95% CI:0.375 (0.169-1.830), P = 0.116) between two groups.

CONCLUSIONS

Thrombolytic-related AHT does not deteriorate short-term and long-term clinical outcome.

Postthrombolytic Antiplatelet Use for Patients with Intercerebral Hemorrhage without Extensive Parenchymal Involvement Does Not Worsen Outcome

Background and Purpose

It is unclear whether postthrombolytic antiplatelet (AP) therapy after thrombolytic-related hemorrhage without extensive parenchymal involvement (THEPI) affects the clinical outcome. This study explored whether AP administration in patients with THEPI affects short- and long-term outcomes.

Methods

All of the data for this study were collected from the Thrombolysis Implementation and Monitor of Acute Ischemic Stroke in China (TIMS-China) registry. Patients with THEPI were assigned to either the AP (AP therapy should be commenced 24 h after intravenous thrombolysis) or AP-naïve groups. THEPI was defined according to European-Australasian Acute Stroke Study II criteria. The 90-day functional outcome, 7-day National Institutes of Health Stroke Scale (NIHSS) score, and 7-day and 90-day mortalities were compared between the AP and AP-naïve groups. Logistic regression analysis was used to evaluate the effects of AP therapy on the short- and long-term clinical outcomes.

Results

Of the 928 patients enrolled from those in the TIMS-China registry (n=1,440), 89 (9.6%) had nonsymptomatic intracerebral hemorrhage (ICH) within 24-36 h after thrombolysis; 33 (37%) of these patients were given AP therapy (AP group) and 56 (63%) were not (AP-naïve group). No significant differences were found for the risk of 7-day aggravated ICH (p=0.998), 7-day NIHSS score (p=0.5491), 7-day mortality [odds ratio (OR)=3.427; 95% confidence interval (95% CI)=0.344-34.160; p=0.294], 90-day mortality (OR=0.788, 95% CI=0.154-4.040, p=0.775), or modified Rankin score 5 or 6 at 90-days (OR=1.108, 95% CI=0.249-4.928, p=0.893) between the AP and AP-naïve groups after THEPI.

Conclusions

Early administration of postthrombolytic AP therapy after THEPI does not worsen either the short- or long-term outcome. AP therapy may be a reasonable treatment option for patients with THEPI to reduce the risk of ischemic stroke recurrence.

New prognostic score for the prediction of 30-day outcome in spontaneous supratentorial cerebral haemorrhage

Aims. The purpose of the present study was to evaluate predictors of outcome in primary supratentorial cerebral haemorrhage. Furthermore, we aimed to develop a prognostic model to predict 30-day fatality. Methods. We retrospectively analyzed a database of 156 patients with spontaneous supratentorial haemorrhage to explore the relationship between clinical and CT characteristics and fatal outcome within 30 days using multiple logistic regression analysis. The analyzed factors included volumetric data assessed by neuropathological and CT volumetry. A second CT scan in survivors or neuropathological ABC/2 volumetry in nonsurvivors was used along with the baseline CT to assess the growth index of haematoma. Results. Systolic blood pressure, serum potassium and glucose levels, platelet count, absolute and relative haematoma volumes, and presence and size of intraventricular haemorrhage statistically significantly predicted the fatal outcome within 30 days. Based on our results we formulated a six-factor scoring algorithm named SUSPEKT to predict outcome. Conclusions. After validation the SUSPEKT score may be applicable in general clinical practice for early patient selection to optimize individual management or for assessment of eligibility for treatment trials.

Hemorrhagic transformation after cerebral infarction: current concepts and challenges

Hemorrhagic transformation (HT) is a frequent complication of acute ischemic stroke that is especially common after thrombolytic therapy. The risk of HT limits the applicability of tissue plasminogen activator (tPA). Here, we sought to review the rate, classification, predictors, possible mechanism, and clinical outcomes of HT, as well as existing therapeutic approaches, in order to call attention to the current challenges in the treatment of this complication.

Haemorrhagic Transformation of Ischaemic Stroke in Young Adults

Background

Frequency, factors associated with, and impact on outcome of haemorrhagic transformation in young adults with ischaemic stroke are unknown.

Methods

Consecutive young patients (age 15–49) with first-ever ischaemic stroke were included, having their first brain computed tomography/magnetic resonance imaging within seven-days of stroke onset, and second within seven-days from the first imaging. Haemorrhagic transformation in any imaging was classified as haemorrhagic infarct or parenchymal haemorrhage within or remote from the infarct. Symptomatic haemorrhagic transformation was defined according to the European Cooperative Acute Stroke Study II (ECASS II) criteria as any haemorrhage leading to a National Institutes of Health Stroke Scale score increase of ≥4 points or death. Unfavourable three-month outcome was defined as a modified Rankin Scale 2–6.

Results

In 636 eligible patients, any haemorrhagic transformation occurred in 79 patients (12·4%; 10·0–15·2%): 66 (10·4%; 8·24–12·9%) had haemorrhagic infarct, and 13 (2·04%; 1·19–3·46%) had parenchymal haemorrhage. Symptomatic haemorrhagic transformation occurred in 16 patients (2·5%; 4·04–1·55%). In logistic regression analysis, independent factors associated with haemorrhagic transformation were large anterior (18·70; 6·72–52·04), large posterior (9·41; 3·13–28·25), medium-sized (odds ratio 3·30; 95% confidence interval 1·14–9·57) lesions, higher low-density lipoprotein level (1·44 per unit increment; 1·10–1·90), and lower platelet count (1·005 per unit decrement; 1·009–1·001). Haemorrhagic infarct (1·76; 0·76–4·11) or parenchymal haemorrhage (2·39; 0·23–24·76) were not associated with unfavourable functional outcome or death at three-months.

Conclusions

In young adults, haemorrhagic transformation of ischaemic stroke occurred in comparable rates to haemorrhagic transformation in elderly patients. Although haemorrhagic transformation was more common in severe strokes, it was the lesion size and baseline stroke severity that were associated with three-month clinical outcome, not haemorrhagic transformation per se.

Increased blood-brain barrier permeability on perfusion computed tomography predicts hemorrhagic transformation in acute ischemic stroke

BACKGROUND/PURPOSE

Perfusion computed tomography (CT) is capable of measuring the permeability surface product (PS). PS reflects the permeability of the blood-brain barrier, involved in the pathophysiology of hemorrhagic transformation (HT) of ischemic stroke. The aim of our study was to determine if an increased PS can predict HT.

METHODS

A total of 86 patients with ischemic stroke were included. They underwent multimodality CT, including the measurement of PS. We compared the clinical and radiological characteristics of patients who developed HT to those who did not, using univariate analysis. Multivariate regression analyses were then used to determine HT predictors.

RESULTS

HT was observed in 27 patients (31%). Infarct PS was significantly associated with HT (p = 0.047), as were atrial fibrillation (p = 0.03), admission National Institute of Health Stroke Scale score (p = 0.02), infarct volume (p = 0.0004), presence of large-vessel occlusion (p = 0.0005) and a poorer collateral status (p = 0.003). Using logistic regression modeling, an infarct PS >0.84 ml/100 g/min was an independent predictor of HT (OR 28, 95% CI 1.75-452.98; p = 0.02). Other independent predictors of HT were infarct volume and a history of atrial fibrillation.

CONCLUSIONS

Our findings suggest that infarct PS can be a predictor of HT and may help clinicians to improve patient care around thrombolysis decisions in the acute phase of ischemic stroke.

Association of CT perfusion parameters with hemorrhagic transformation in acute ischemic stroke

BACKGROUND AND PURPOSE

Prediction of hemorrhagic transformation in acute ischemic stroke could help determine treatment and prognostication. With increasing numbers of patients with acute ischemic stroke undergoing multimodal CT imaging, we examined whether CT perfusion could predict hemorrhagic transformation in acute ischemic stroke.

MATERIALS AND METHODS

Patients with acute ischemic stroke who underwent CTP scanning within 12 hours of symptom onset were examined. Patients with and without hemorrhagic transformation were defined as cases and controls, respectively, and were matched as to IV rtPA administration and presentation NIHSS score (± 2). Relative mean transit time, relative CBF, and relative CBV values were calculated from CTP maps and normalized to the contralateral side. Receiver operating characteristic analysis curves were created, and threshold values for significant CTP parameters were obtained to predict hemorrhagic transformation.

RESULTS

Of 83 patients with acute ischemic stroke, 16 developed hemorrhagic transformation (19.28%). By matching, 38 controls were found for only 14 patients with hemorrhagic transformation. Among the matched patients with hemorrhagic transformation, 13 developed hemorrhagic infarction (6 hemorrhagic infarction 1 and 7 hemorrhagic infarction 2) and 1 developed parenchymal hematoma 2. There was no significant difference between cases and controls with respect to age, sex, time to presentation from symptom onset, and comorbidities. Cases had significantly lower median rCBV (8% lower) compared with controls (11% higher) (P = .009; odds ratio, 1.14 for a 0.1-U decrease in rCBV). There was no difference in median total volume of ischemia, rMTT, and rCBF among cases and controls. The area under the receiver operating characteristic was computed to be 0.83 (standard error, 0.08), with a cutoff point for rCBV of 1.09.

CONCLUSIONS

Of the examined CTP parameters, only lower rCBV was found to be significantly associated with a relatively higher chance of hemorrhagic transformation.

[Secondary prophylaxis of stroke from a neurological perspective]

Patients who have suffered ischemic stroke or transient ischemic attack (TIA) are at high risk of recurrent stroke, myocardial infarction or vascular death. Early pathophysiological based diagnostics and resulting secondary prevention are critical for reduction of stroke risk. Optimization of lifestyle factors, treatment of hypertension, cholesterol reduction with statins and use of antiplatelet agents in non-cardiogenic or anticoagulation in cardiogenic ischemia as well as internal carotid revascularization, in cases of more than 50% diameter stenosis of the internal carotid artery, are proven strategies for reduction of ischemic stroke risk.

Hemorrhagic transformation of ischemic stroke in diabetics on sulfonylureas

OBJECTIVE

Disability or death occurs more frequently in patients with hemorrhagic transformation (HT) after ischemic stroke. In rat models of stroke, sulfonylurea (SU) drugs such as glibenclamide (adopted US name, glyburide) confer protection against swelling and HT through actions on the novel SUR1-regulated NC(Ca-ATP) channel. Here, we sought to determine whether the use of SU drugs in patients with diabetes mellitus (DM) presenting with acute ischemic stroke might influence the incidence of HT.

METHODS

We retrospectively analyzed data on 220 patients with DM who presented with acute ischemic stroke, 43 of whom were managed with and continued to receive SU drugs, and 177 of whom were managed without (controls).

RESULTS

During a median length of stay in hospital of 11 days, 20 control patients (11%) experienced symptomatic HT (sHT), whereas no patient in the SU group experienced sHT (p = 0.016). No patient in the SU group died, compared to 18 (10%) in the control group (p = 0.027). Similarly favorable outcomes were observed after matching for baseline imbalances and excluding outliers. In support of the proposed mechanism, we present a case of sHT in which an analysis of brain tissues obtained intraoperatively showed prominent upregulation of SUR1, the target of SU drugs, in microvessels and neurons.

INTERPRETATION

We conclude that, in diabetic patients with acute ischemic stroke, prior and continued use of SU drugs is associated with reduced sHT compared to those whose treatment regimen does not include SU drugs.

The Influence of Stroke Risk Factors and Comorbidities on Assessment of Stroke Therapies in Humans and Animals

The main driving force behind the assessment of novel pharmacological agents in animal models of stroke is to deliver new drugs to treat the human disease rather than to increase knowledge of stroke pathophysiology. There are numerous animal models of the ischaemic process and it appears that the same processes operate in humans. Yet, despite these similarities, the drugs that appear effective in animal models have not worked in clinical trials. To date, tissue plasminogen activator is the only drug that has been successfully used at the bedside in hyperacute stroke management. Several reasons have been put forth to explain this, but the failure to consider comorbidities and risk factors common in older people is an important one. In this article, we review the impact of the risk factors most studied in animal models of acute stroke and highlight the parallels with human stroke, and, where possible, their influence on evaluation of therapeutic strategies.

Adverse effect of early epileptic seizures in patients receiving endovascular therapy for acute stroke

BACKGROUND AND PURPOSE

The aim of this study was to analyze epileptic seizures and their impact on outcome in patients with stroke treated with endovascular therapy.

METHODS

From December 1992 to December 2010 we managed 805 patients with stroke with endovascular therapy. Epileptic seizures, bleeding complications, and 3-month outcomes were recorded prospectively. Outcomes of patients with early seizures (within 24 hours of stroke onset) and patients with late seizures (>24 hours after stroke) were compared with outcomes of seizure-free patients using uni- and multivariable statistics.

RESULTS

Forty-four of 805 patients (5.5%) had seizures between stroke onset and 3-month follow-up, 26 patients early and 18 late. Outcome of patients with late seizures and seizure-free patients was similar (P=0.144 and 0.807). Patients with early seizures had higher baseline National Institutes of Health Stroke Scale (P=0.023) and were younger (P=0.021) than seizure-free patients. Their mortality rate was 50% compared with 22.3% of the seizure free-patients (P=0.003), and less patients reached a favorable outcome (modified Rankin Scale 0-2): 15.4% and 46.8%, respectively (P=0.001). Early seizures independently predicted an unfavorable outcome (P=0.014; OR, 4.749; 95% CI, 0.376-3.914) and increased mortality (P=0.001; OR, 5.861; 95% CI, 0.770-2.947) in multiregression analysis. Patients with early seizures had a 1.6-fold higher risk for unfavorable outcome and a 2.2-fold higher risk for death compared with seizure-free patients.

CONCLUSIONS

Seizures within 24 hours of stroke onset were associated with worse outcome in patients with stroke undergoing endovascular therapy. Our findings confirm a need for trials for prophylactic anticonvulsive treatment in patients receiving endovascular therapy for acute stroke.

Combined systemic thrombolysis with alteplase and early hyperbaric oxygen therapy in experimental embolic stroke in rats: relationship to functional outcome and reduction of structural damage

INTRODUCTION

The only causal therapy in ischemic stroke is thrombolysis with recombinant tissue plasminogen activator (rtPA), but it is feasible only for few patients, and new therapies are needed. This study investigates the effects of systemic thrombolysis with rtPA combined with hyperbaric oxygen therapy (HBOT) in embolic stroke in rats.

METHODS

In 22 male Wistar rats, an embolic ischemic stroke was induced. The animals were randomized to one of four groups: control, thrombolysis alone, HBOT sequential or HBOT parallel with thrombolysis. HBOT (2.4 ATA, 1 h) started 45 min (sequential) or 120 min (parallel) after stroke. rtPA was given intravenously 120 min after stroke onset. Functional tests were performed after stroke induction and after treatment. After 6 h infarct volume and intracerebral hemorrhagic complications were assessed.

RESULTS

Compared to the control group only the combination of HBOT and thrombolysis significantly improved the functional outcome (p=0.03) and reduced the infarct volume (p=0.01), whereas thrombolysis alone did not show a significant benefit. In all treatment groups there was a trend towards fewer hemorrhagic transformations.

CONCLUSION

Hyperbaric oxygen in combination with thrombolysis shows neuroprotection in acute ischemic stroke in rats by reducing infarct volume and improving functional outcome in the early poststroke period.

Predictors and early outcome of hemorrhagic transformation after acute ischemic stroke

BACKGROUND

Hemorrhagic transformation (HT) after acute ischemic stroke is frequently detected using magnetic resonance imaging (MRI), in particular in patients treated with tissue plasminogen activator (tPA). Knowledge about causes and early clinical consequences of HT mostly arises from computed tomography-based studies. We analyzed potential predictors and early outcome of HT after stroke detected by MRI with T(2)*-weighted gradient echo sequences (T(2)*-MRI).

METHODS

122 consecutive stroke patients (mean age 65.5 years, 41% women) who underwent T(2)*-MRI within 6-60 h after stroke onset were included. 25.4% of patients were treated with tPA; the overall detection rate of HT on T(2)*-MRI was 20.5%. Potential predictors of HT, such as age, sex, blood pressure, stroke etiology, prior antithrombotic medication, neurological deficit on admission, tPA treatment, and specific MRI findings, were analyzed. In addition, we evaluated the effect of HT on early outcome: a decrease of >4 points on the National Institute of Health Stroke Scale (NIHSS) on day 5 was considered early improvement, and an increase of >4 points was considered early deterioration.

RESULTS

The main predictor for occurrence of HT was tPA treatment (48.4 vs. 11.1%; odds ratio 7.50; 95% confidence interval 2.9-19.7; p < 0.001). Furthermore, the development of HT was associated with a severer neurological deficit on admission (mean NIHSS score 9.9 vs. 5.9; p = 0.003), and territorial infarction (88 vs. 58.8%; p = 0.007). 19 patients (15.6%) showed early improvement which was associated with the occurrence of HT (p = 0.011) and tPA treatment (p < 0.001).

CONCLUSIONS

HT is a frequent finding on T(2)*-MRI in patients with acute ischemic stroke associated with tPA treatment, territorial infarction and severer neurological deficits on admission. However, HT does not cause clinical deterioration; it is rather related to a favorable early outcome likely reflecting early recanalization and better reperfusion in these patients.

Asymptomatic Hemorrhagic Transformation of Infarction and Its Relationship With Functional Outcome and Stroke Subtype

Background and Purpose— Asymptomatic hemorrhagic transformation of infarction (AHTI) is common, but its risk factors and relationship with functional outcome are poorly defined.

Methods— The analyses used data from the Tinzapararin in Acute Ischaemic Stroke Trial, a randomized controlled trial assessing tinzaparin (low molecular weight heparin) versus aspirin in 1484 patients with acute ischemic stroke. CT head scans (baseline, day 10) were adjudicated for the presence of hemorrhagic transformation. Stroke subtype was classified according to modified Trial of Org 10172 in Acute Stroke Treatment (small vessel, large vessel, cardioembolic) and the Oxfordshire Community Stroke Project (total anterior, partial anterior, lacunar, and posterior circulatory syndromes). Modified Rankin scale and Barthel Index were measured at 3 and 6 months. Analyses were adjusted for age, sex, severity, blood pressure, infarct volume, and treatment. Symptomatic hemorrhage was excluded.

Results— At day 10, AHTI did not differ between aspirin (300 mg; 32.8%) and medium-dose (100 IU/kg; 36.0%) and high-dose (175 IU/kg; 31.4%) tinzaparin groups ( P =0.44). Relative to lacunar stroke, AHTI on follow-up CT was significantly increased in total anterior circulation syndrome (odds ratio, 11.5; 95% CI, 7.1 to 18.7) and partial anterior circulation syndrome (odds ratio, 7.2; 95% CI, 4.5 to 11.4) stroke. Similarly, relative to small vessel disease, AHTI was increased in large vessel (odds ratio, 15.1; 95% CI, 9.4 to 24.3) and cardioembolic (odds ratio, 14.1; 95% CI, 8.5 to 23.5) stroke. After adjustment for infarct volume, the presence of AHTI was not associated with outcome at 3 or 6 months as measured by the modified Rankin Scale and Barthel Index.

Conclusions— AHTI is increased in ischemic stroke with cortical syndromes and of large vessel or cardioembolic etiology. Heparin does not increase AHTI. AHTI is not associated with functional outcome.