Functional Outcome of Hemorrhagic Transformation after Thrombolysis for Ischemic Stroke: A Prospective Study

Prognostic significance of the clinical and radiological haemorrhagic transformation subtypes in acute ischaemic stroke: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

The aim was to investigate the associations of haemorrhagic transformation (HT) and its clinical and radiological subtypes with functional outcome, mortality, early neurological deterioration (END) and neurological complications in patients with acute ischaemic stroke (AIS).

METHODS

A systematic review and meta-analysis of observational studies on the associations of overall HT, clinical HT subtypes (asymptomatic intracerebral haemorrhage [aICH] and symptomatic intracerebral haemorrhage [sICH]) or radiological HT subtypes (haemorrhagic infarction [HI-1 or HI-2] and parenchymal haemorrhage [PH-1 or PH-2]) with prognosis in patients with AIS was performed. PubMed, Web of Science and Embase were systematically searched. Random effects models were used to calculate pooled estimates.

RESULTS

Fifty-one studies with 100,510 patients were pooled in the meta-analysis. Overall HT was associated with worse functional outcome (odds ratio [OR] 2.12, 95% confidence interval [CI] 1.55-2.90), increased mortality (OR 1.87, 95% CI 1.52-2.30), END (OR 2.35, 95% CI 1.46-3.77), early-onset seizures (OR 2.58, 95% CI 1.63-4.10) and post-stroke epilepsy (OR 2.23, 95% CI 1.11-4.49). For clinical subtypes, sICH remained significantly associated with the aforementioned poor prognoses except post-stroke epilepsy, and aICH was associated with worse functional outcome but was unrelated to mortality. For radiological subtypes, PH (especially PH-2) was strongly associated with poor prognosis. HI-2 was associated with worse functional outcome, and HI-1 was associated with a lower risk of mortality and END.

CONCLUSIONS

Regardless of whether AIS patients undergo thrombolysis or thrombectomy, overall HT, sICH and PH (especially PH-2) are associated with a substantially increased risk of worse functional outcome, mortality, END or neurological complications. The presence of aICH is related to worse functional outcome but is independent of increased mortality. HI-2 impairs functional independence, and HI-1 does not cause neurological impairment.

Prognosis associated with asymptomatic intracranial hemorrhage after acute ischemic stroke: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

It remains inconclusive whether asymptomatic intracranial hemorrhage (aICH) after acute ischemic stroke is innocuous. We aimed to conduct a meta-analysis assessing the relationship between the aICH and poor neurological outcomes.

METHODS

We searched PubMed, EMBASE and Web of Science from their inception to 30 November 2021 and performed a meta-analysis on the association between the aICH and neurological prognosis after acute ischemic stroke at 3 months, including poor outcomes (modified Rankin Scale [mRS] score ≥ 2 or mRS ≥ 3) and mortality.

RESULTS

Fourteen studies were included in the analysis, reporting on a total of 10,915 participants after acute ischemic stroke. The risks of poor outcome (mRS ≥ 2 or mRS ≥ 3) in patients with aICH were significantly higher than patients without ICH (OR 1.70, 95% CI 1.33-2.18; OR 1.43, 95% CI 1.20-1.70, respectively), based on adjusted data. The difference between the two groups was not significant for mortality. The results of subgroup analysis showed aICH were associated with higher ratio of mild poor prognosis (mRS ≥ 2) (OR 1.59, 95% CI 1.11-2.27), but it had no association with functional dependence (mRS ≥ 3) after recanalization. No significant influence of aICH on poor outcome (mRS ≥ 3) was found in non-recanalization group. Further stratified analysis revealed that only aICH with patients receiving endovascular therapy (EVT) could increase the risk of mild poor prognosis (mRS ≥ 2) at 3 months.

CONCLUSIONS

Our results indicate that compared with patients without ICH, those who developed aICH during the acute stage of ischemic stroke had an increasing risk of worse outcome, especially in patients with endovascular therapy.

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.

Exogenous insulin-like growth factor 1 attenuates acute ischemic stroke-induced spatial memory impairment via modulating inflammatory response and tau phosphorylation

Acute ischemic stroke is one of the main causes of mortality and morbidity worldwide. The present study aimed to explore the effects of exogenous insulin-like growth factor 1 (IGF-1) on the cognitive injuries induced by acute ischemic stroke and the underlying mechanisms. Acute ischemic stroke rat model was established via transient occlusion of the left middle cerebral artery to male Sprague-Dawley rats. IGF-1 was administered intravenously every other day 24 h after surgery for 14 days. Cognitive functions were determined by Morris water maze assay. Cerebral infarction and edema were determined by riphenyltetrazolium chloride staining and cerebral water content measurement. ELISA and Western blot were performed to detect concentrations of target proteins. Ischemic stroke rats exhibited reduced plasma IGF-1 level and impaired cognitive functions. Intravenous IGF-1 delivery increased the IGF-1 levels in plasma, ischemic amygdala, hippocampus and cortex, improved the neurological dysfunction, cognitive deficits, cerebral infarction and brain edema. Furthermore, IGF-1 relieved the systemic and cerebral inflammatory response by inhibiting the secretion of pro-inflammatory cytokines, interleukin (IL)-6, IL-1β, and tumor necrosis factor alpha (TNF-α), in serum and ischemic hippocampus of ischemic rats. Additionally, IGF-1 attenuated tau phosphorylation in ischemic hippocampus. In short, intravenous IGF-1 administration attenuates acute ischemic stroke-induced cognitive injuries in the experimental rat model possibly via modulating inflammatory response and tau phosphorylation, and might be of promising therapeutic value to ischemic stroke in the future.

The Role of Hemorrhagic Transformation in Acute Ischemic Stroke Upon Clinical Complications and Outcomes

BACKGROUND AND PURPOSE

Hemorrhagic transformation (HT) is a common neurological complication after ischemic stroke. The influence of symptomatic HT upon clinical outcomes post-stroke is well established, however, the role of asymptomatic HT upon prognosis is still unclear. We aimed to analyze the relationship between HT, clinical complications and outcomes in patients not submitted to reperfusion therapies (RT).

METHODS

We included 448 randomly selected patients admitted with acute ischemic stroke to a tertiary hospital stroke unit from 2015 to 2017. Patients submitted to RT were excluded. All patients were evaluated with computed tomography (CT) at admission and within 7 days from the initial CT. Patients with HT were divided into two groups: symptomatic and asymptomatic cases based on the ECASS II definition. A good clinical outcome was defined as a modified Rankin Scale (mRS) 0-2 at discharge.

RESULTS

A total of 95 patients (21.2%) had HT (51 asymptomatic and 44 symptomatic). Age, NIHSS at admission and symptomatic HT were associated with a higher risk of developing pneumonia and seizures during hospitalization. Symptomatic HT was also associated with a prolonged length of hospitalization and death and inversely associated with good clinical outcomes at discharge (OR 0.96, 95% CI 0.94-0.98, p<0.001). In an adjusted analysis, even asymptomatic HT was independently associated with worse clinical outcomes at discharge (mRS 4-6) (OR 5.99, 95% CI 1.83-19.58, p = 0.003).

CONCLUSIONS

Symptomatic HT is associated with a higher risk of clinical complications, prolonged hospitalization, death and worse clinical outcome at discharge. Furthermore, even patients with asymptomatic HT had a higher chance of worse clinical outcomes at discharge.

Susceptibility-weighted Imaging in Thrombolytic Therapy of Acute Ischemic Stroke

Objective:

To provide a comprehensive and latest overview of susceptibility-weighted imaging (SWI) in the application of thrombolysis in acute ischemic stroke, and to update the decision-making effect and clinical value of SWI on identifying stroke patients suitable for thrombolytic therapy and possible benefits and risks followed.

Data Sources:

Literatures referred to this review were collected from PubMed, Medline, and EMBASE published till May 2017, using the search terms including susceptibility-weighted imaging, gradient-echo, T2*, thrombolysis, recombinant tissue plasminogen activator (rt-PA), thrombolytic therapy, and stroke.

Study Selection:

Papers in English or with available English abstracts were considered, with no limitation of study design. References were also identified from the bibliographies of identified articles and the authors’ files.

Results:

SWI is of guiding significance for thrombolytic therapy in stroke patients, it can predict the location and length of thrombus and ischemic penumbra. It is worthy of noting that susceptibility vessel sign (SVS) on SWI can be used to predict recanalization after thrombolytic therapy and whether it is better to implement endovascular thrombolectomy in combination or alone. SWI is sensitive in detecting cerebral microbleed (CMB), and CMB might not be a contraindication for thrombolytic therapy, yet CMBs in multiple foci could possibly be related to intracranial hemorrhage (ICH) after thrombolysis. SVS and CMB on SWI sequence are of instructive value in performing antiplatelet therapy after thrombolytic therapy. Cerebral venous change on SWI is related to lower recanalization rate and poor outcome after thrombolysis.

Conclusions:

It seems that SWI can be applied to guide individualized thrombolytic therapies and assist clinicians in making better decisions by weighing benefits and risks. However, there still exist controversies about the relationship between signs on SWI and thrombolytic therapy.

Free Radical Damage in Ischemia-Reperfusion Injury: An Obstacle in Acute Ischemic Stroke after Revascularization Therapy

Acute ischemic stroke is a common cause of morbidity and mortality worldwide. Thrombolysis with recombinant tissue plasminogen activator and endovascular thrombectomy are the main revascularization therapies for acute ischemic stroke. However, ischemia-reperfusion injury after revascularization therapy can result in worsening outcomes. Among all possible pathological mechanisms of ischemia-reperfusion injury, free radical damage (mainly oxidative/nitrosative stress injury) has been found to play a key role in the process. Free radicals lead to protein dysfunction, DNA damage, and lipid peroxidation, resulting in cell death. Additionally, free radical damage has a strong connection with inducing hemorrhagic transformation and cerebral edema, which are the major complications of revascularization therapy, and mainly influencing neurological outcomes due to the disruption of the blood-brain barrier. In order to get a better clinical prognosis, more and more studies focus on the pharmaceutical and nonpharmaceutical neuroprotective therapies against free radical damage. This review discusses the pathological mechanisms of free radicals in ischemia-reperfusion injury and adjunctive neuroprotective therapies combined with revascularization therapy against free radical damage.

Co-administration of tissue plasminogen activator and hyperbaric oxygen in ischemic stroke: a continued promise for neuroprotection

Intravenous recombinant tissue-type plasminogen activator (r-tPA, alteplase) remains the recommended therapy for acute ischemic stroke. However, several factors are limiting its practical use. It makes it urgent for us to search more efficient strategies that can save the ischemic neurons, and safely extend the time window, while in the mean time reducing the detrimental effects for stroke thrombolysis. Hyperbaric oxygen therapy (HBOT) is considered to be potentially neuroprotective. Co-administration of r-tPA and HBOT has already been proved to be effective, safe and feasible in myocardial infarction. In this article, we would like to review whether HBOT has any beneficial effects on r-tPA thrombolysis. If there is, what is the underlying possible mechanisms and how to optimize for maximal effects?