Aristeidis H. Katsanos

Safety of Intravenous Thrombolysis in Stroke Mimics: Prospective 5-Year Study and Comprehensive Meta-Analysis

Background and Purpose— Shortening door-to-needle time may lead to inadvertent intravenous thrombolysis (IVT) administration in stroke mimics (SMs). We sought to determine the safety of IVT in SMs using prospective, single-center data and by conducting a comprehensive meta-analysis of reported case-series. Methods— We prospectively analyzed consecutive IVT-treated patients during a 5-year period at a tertiary care stroke center. A systematic review and meta-analysis of case-series reporting safety of IVT in SMs and confirmed acute ischemic stroke were conducted. Symptomatic intracerebral hemorrhage was defined as imaging evidence of ICH with an National Institutes of Health Stroke scale increase of ≥4 points. Favorable functional outcome at hospital discharge was defined as a modified Rankin Scale score of 0 to 1. Results— Of 516 consecutive IVT patients at our tertiary care center (50% men; mean age, 60±14 years; median National Institutes of Health Stroke scale, 11; range, 3–22), SMs comprised 75 cases. Symptomatic intracerebral hemorrhage occurred in 1 patient, whereas we documented no cases of orolingual edema or major extracranial hemorrhagic complications. In meta-analysis of 9 studies (8942 IVT-treated patients), the pooled rates of symptomatic intracerebral hemorrhage and orolingual edema among 392 patients with SM treated with IVT were 0.5% (95% confidence interval, 0%–2%) and 0.3% (95% confidence interval, 0%–2%), respectively. Patients with SM were found to have a significantly lower risk for symptomatic intracerebral hemorrhage compared with patients with acute ischemic stroke (risk ratio=0.33; 95% confidence interval, 0.14–0.77; P=0.010), with no evidence of heterogeneity or publication bias. Favorable functional outcome was almost 3-fold higher in patients with SM in comparison with patients with acute ischemic stroke (risk ratio=2.78; 95% confidence interval, 2.07–3.73; P<0.00001). Conclusions— Our prospective, single-center experience coupled with the findings of the comprehensive meta-analysis underscores the safety of IVT in SM.

Intensive blood pressure reduction in acute intracerebral hemorrhage: A meta-analysis

Objective: The aim of the present systematic review and meta-analysis was to evaluate the safety and efficacy of intensive blood pressure (BP) reduction in patients with acute-onset intracerebral hemorrhage (ICH) using data from randomized controlled trials. Methods: We conducted a systematic review and meta-analysis according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines of all available randomized controlled trials that randomized patients with acute ICH to either intensive or guideline BP-reduction protocols. Results: We identified 4 eligible studies, including a total of 3,315 patients (mean age 63.4 ± 1.4 years, 64% men). Death rates were similar between patients randomized to intensive BP-lowering treatment and those receiving guideline BP-lowering treatment (odds ratio = 1.01, 95% confidence interval: 0.83–1.23; p = 0.914). Intensive BP-lowering treatment tended to be associated with lower 3-month death or dependency (modified Rankin Scale grades 3–6) compared with guideline treatment (odds ratio = 0.87, 95% confidence interval: 0.76–1.01; p = 0.062). No evidence of heterogeneity between estimates (I2 = 0%; p = 0.723), or publication bias in the funnel plots (p = 0.993, Egger statistical test), was detected. Intensive BP reduction was also associated with a greater attenuation of absolute hematoma growth at 24 hours (standardized mean difference ± SE: −0.110 ± 0.053; p = 0.038). Conclusions: Our findings indicate that intensive BP management in patients with acute ICH is safe. Fewer intensively treated patients had unfavorable 3-month functional outcome although this finding did not reach significance. Moreover, intensive BP reduction appears to be associated with a greater attenuation of absolute hematoma growth at 24 hours.

Risk of Symptomatic Intracerebral Hemorrhage After Intravenous Thrombolysis in Patients With Acute Ischemic Stroke and High Cerebral Microbleed Burden: A Meta-analysis.

IMPORTANCE Cerebral microbleeds (CMBs) have been established as an independent predictor of cerebral bleeding. There are contradictory data regarding the potential association of CMB burden with the risk of symptomatic intracerebral hemorrhage (sICH) in patients with acute ischemic stroke (AIS) treated with intravenous thrombolysis (IVT). OBJECTIVE To investigate the association of high CMB burden (>10 CMBs on a pre-IVT magnetic image resonance [MRI] scan) with the risk of sICH following IVT for AIS. DATA SOURCES Eligible studies were identified by searching Medline and Scopus databases. No language or other restrictions were imposed. The literature search was conducted on October 7, 2015. This meta-analysis has adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was written according to the Meta-analysis of Observational Studies in Epidemiology (MOOSE) proposal. STUDY SELECTION Eligible prospective study protocols that reported sICH rates in patients with AIS who underwent MRI for CMB screening prior to IVT. DATA EXTRACTION AND SYNTHESIS The reported rates of sICH complicating IVT in patients with AIS with pretreatment MRI were extracted independently for groups of patients with 0 CMBs (CMB absence), 1 or more CMBs (CMB presence), 1 to 10 CMBs (low to moderate CMB burden), and more than 10 CMBs (high CMB burden). An individual-patient data meta-analysis was also performed in the included studies that provided complete patient data sets. MAIN OUTCOMES AND MEASURES Symptomatic intracerebral hemorrhage based on the European Cooperative Acute Stroke Study-II definition (any intracranial bleed with ≥4 points worsening on the National Institutes of Health Stroke Scale score). RESULTS We included 9 studies comprising 2479 patients with AIS. The risk of sICH after IVT was found to be higher in patients with evidence of CMB presence, compared with patients without CMBs (risk ratio [RR], 2.36; 95% CI, 1.21-4.61; P = .01). A higher risk for sICH after IVT was detected in patients with high CMB burden (>10 CMBs) when compared with patients with 0 to 10 CMBs (RR, 12.10; 95% CI, 4.36-33.57; P < .001) or 1 to 10 CMBs (RR, 7.01; 95% CI, 3.20-15.38; P < .001) on pretreatment MRI. In the individual-patient data meta-analysis, high CMB burden was associated with increased likelihood of sICH before (unadjusted odds ratio, 31.06; 95% CI, 7.12-135.44; P < .001) and after (adjusted odds ratio, 18.17; 95% CI, 2.39-138.22; P = .005) adjusting for potential confounders. CONCLUSIONS AND RELEVANCE Presence of CMB and high CMB burdens on pretreatment MRI were independently associated with sICH in patients with AIS treated with IVT. High CMB burden may be included in individual risk stratification scores predicting sICH risk following IVT for AIS.

Is Vertebral Artery Hypoplasia a Predisposing Factor for Posterior Circulation Cerebral Ischemic Events? A Comprehensive Review

Vertebral artery hypoplasia is not currently considered an independent risk factor for stroke. Emerging evidence suggest that vertebral artery hypoplasia may contribute to posterior circulation ischemic events, especially when other risk factors coexist. In the present literature review, we present published data to discuss the relationship between a hypoplastic vertebral artery and posterior circulation cerebral ischemia. Despite difficulties and controversies in the accurate definition and prevalence estimation of vertebral artery hypoplasia, ultrasound studies reveal that the reduced blood flow observed ipsilateral to the hypoplastic vertebral artery may result in local cerebral hypoperfusion and subsequent focal neurological symptomatology. That risk of cerebral ischemia is related to the severity of the hypoplasia, suggesting that the smaller of paired arteries are more vulnerable to occlusion. Existing cohort studies further support clinical observations that hypoplastic vertebral artery enhances synergistically the vascular risk for posterior circulation ischemic events and is closely associated with both atherosclerotic and prothrombotic processes.

Statins and cerebral hemodynamics

HMG-CoA reductase inhibitors (statins) are associated with improved stroke outcome. This observation has been attributed in part to the palliative effect of statins on cerebral hemodynamics and cerebral auto regulation (CA), which are mediated mainly through the upregulation of endothelium nitric oxide synthase (eNOS). Several animal studies indicate that statin pretreatment enhances cerebral blood flow after ischemic stroke, although this finding is not further supported in clinical settings. Cerebral vasomotor reactivity, however, is significantly improved after long-term statin administration in most patients with severe small vessel disease, aneurysmal subarachnoid hemorrhage, or impaired baseline CA.

Recurrent Stroke and Patent Foramen Ovale A Systematic Review and Meta-Analysis

Background and Purpose— Recurrent cerebrovascular events are frequent in medically treated patients with patent foramen ovale (PFO), but it still remains unclear whether PFO is a causal or an incidental finding. Further uncertainty exists on whether the size of functional shunting could represent a potential risk factor. The aim of the present study was to evaluate if the presence of PFO is associated with an increased risk of recurrent stroke or transient ischemic attack and to investigate further if this relationship is related to the shunt size. Methods— We conducted a systematic review and meta-analysis according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines of all available prospective studies reporting recurrent cerebrovascular events defined as cryptogenic stroke and transient ischemic attacks in medically treated patients with PFO diagnosed by echocardiography or transcranial sonography. Results— We identified 14 eligible studies including a total of 4251 patients. Patients with stroke with PFO did not have a higher risk of the combined outcome of recurrent stroke/transient ischemic attack (risk ratio=1.18; 95% confidence interval=0.78–1.79; P=0.43) or in the incidence of recurrent strokes (risk ratio =0.85; 95% confidence interval=0.59–1.22; P=0.37) in comparison with stroke patients without PFO. In addition, PFO size was not associated with the risk of recurrent stroke or transient ischemic attack. We also documented no evidence of heterogeneity across the included studies. Conclusions— Our findings indicate that medically treated patients with PFO do not have a higher risk for recurrent cryptogenic cerebrovascular events, compared with those without PFO. No relation between the degree of PFO and the risk of future cerebrovascular events was identified.

Complex Atheromatous Plaques in the Descending Aorta and the Risk of Stroke: A Systematic Review and Meta-Analysis

Background and Purpose— Proximal aortic plaques, especially in the aortic arch, have already been established as an important cause of stroke and peripheral embolism. However, aortic plaques situated in the descending thoracic aorta have recently been postulated as a potential embolic source in patients with cryptogenic cerebral infarction through retrograde aortic flow. The aim of the present study was to evaluate the potential association of descending aorta atheromatosis with cerebral ischemia. Methods— We conducted a systematic review and meta-analysis of all available prospective observational studies reporting the prevalence of complex atheromatous plaques in the descending aorta in patients with stroke and in unselected populations undergoing examination with transesophageal echocardiography. Results— We identified 11 eligible studies including a total of 4000 patients (667 patients with stroke and 3333 unselected individuals; mean age, 65 years; 55% men). On baseline transesophageal echocardiograpic examination, the prevalence of complex atheromatous plaques in the descending aorta was higher (P=0.001) in patients with stroke (25.4%; 95% confidence interval, 14.6–40.4%) compared with unselected individuals (6.1%; 95% confidence interval, 3.4–10%). However, no significant difference (P=0.059) in the prevalence of complex atheromatous plaques in the descending aorta was found between patients with cryptogenic (21.8%; 95% confidence interval, 17.5–26.9%) and unclassified (28.3%; 95% confidence interval, 23.9–33.1%) cerebral infarction. Conclusions— Our findings indicate that the presence of complex plaques in the descending aorta is presumably a marker of generalized atherosclerosis and high vascular risk. The present analyses do not provide any further evidence for a direct causal relationship between descending aorta atherosclerosis and cerebral embolism.

Fibrinolysis for Intraventricular Hemorrhage An Updated Meta-Analysis and Systematic Review of the Literature

Background and Purpose— Intraventricular hemorrhage is associated with high mortality and poor functional outcome. The use of intraventricular fibrinolytic (IVF) therapy as an intervention in intraventricular hemorrhage is an evolving therapy with conflicting reports in the literature. The goal of this study is to investigate the impact of IVF on mortality, functional outcome, ventriculitis, shunt dependence, and rehemorrhage. Methods— During March and April 2014, a systematic literature search was performed identifying 1359 articles. Of these, 24 met inclusion criteria. A random effects meta-analysis was performed using both pooled and subset analysis based on study type. Results— Our meta-analysis demonstrated that IVF reduced mortality in intraventricular hemorrhage by nearly half (relative risk [RR], 0.55; 95% confidence interval [CI], 0.42–0.71; P<0.00001), increased the likelihood of good functional outcome by 66% (RR, 1.66; 95% CI, 1.27–2.19; P=0.0003), and also decreased the rate of shunt dependence (RR, 0.62; 95% CI, 0.42–0.93; P=0.02). IVF was not found to be associated with increased rates of ventriculitis (RR=1.46; 95% CI, 0.77–2.76; P=0.25) or rehemorrhage (RR=1.06; 95% CI, 0.66–1.70; P=0.80). We detected no evidence of publication bias. Conclusions— Our meta-analysis showed that IVF is safe and could be an effective strategy for the treatment of intraventricular hemorrhage. It may reduce mortality, improve functional outcome, and diminish the need for permanent ventricular shunting, while not increasing the risk of ventriculitis or rehemorrhage.

Electrocardiographic abnormalities and cardiac arrhythmias in structural brain lesions.

Cardiac arrhythmias and electrocardiographic abnormalities are frequently observed after acute cerebrovascular events. The precise mechanism that leads to the development of these arrhythmias is still uncertain, though increasing evidence suggests that it is mainly due to autonomic nervous system dysregulation. In massive brain lesions sympathetic predominance and parasympathetic withdrawal during the first 72 h are associated with the occurrence of severe secondary complications in the first week. Right insular cortex lesions are also related with sympathetic overactivation and with a higher incidence of electrocardiographic abnormalities, mostly QT prolongation, in patients with ischemic stroke. Additionally, female sex and hypokalemia are independent risk factors for severe prolongation of the QT interval which subsequently results in malignant arrhythmias and poor outcome. The prognostic value of repolarization changes commonly seen after aneurysmal subarachnoid hemorrhage, such as ST segment, T wave, and U wave abnormalities, still remains controversial. In patients with traumatic brain injury both intracranial hypertension and cerebral hypoperfusion correlate with low heart rate variability and increased mortality. Given that there are no firm guidelines for the prevention or treatment of the arrhythmias that appear after cerebral incidents this review aims to highlight important issues on this topic. Selected patients with the aforementioned risk factors could benefit from electrocardiographic monitoring, reassessment of the medications that prolong QTc interval, and administration of antiadrenergic agents. Further research is required in order to validate these assumptions and to establish specific therapeutic strategies.

Statin pretreatment is associated with better outcomes in large artery atherosclerotic stroke

Objective: Even though statin pretreatment is associated with better functional outcomes and lower risk of mortality in acute ischemic stroke, there are limited data evaluating this association in acute ischemic stroke due to large artery atherosclerosis (LAA), which carries the highest risk of early stroke recurrence. Methods: Consecutive patients with acute LAA were prospectively evaluated from 7 tertiary-care stroke centers during a 3-year period. Statin pretreatment, demographics, vascular risk factors, and admission and discharge stroke severity were recorded. The outcome events of interest were neurologic improvement during hospitalization (quantified as the relative decrease in NIH Stroke Scale score at discharge in comparison to hospital admission), favorable functional outcome (FFO) (defined as modified Rankin Scale score of 0–1), recurrent stroke, and death at 1 month. Statistical analyses were performed using univariable and multivariable Cox regression models adjusting for potential confounders. All analyses were repeated following propensity score matching. Results: Statin pretreatment was documented in 192 (37.2%) of 516 consecutive patients with LAA (mean age: 65 ± 13 years; 60.8% men; median NIH Stroke Scale score: 9 points, interquartile range: 5–18). Statin pretreatment was associated with greater neurologic improvement during hospitalization and higher rates of 30-day FFO in unmatched and matched (odds ratio for FFO: 2.44; 95% confidence interval [CI]: 1.07–5.53) analyses. It was also related to lower risk of 1-month mortality and stroke recurrence in unmatched and matched analyses (hazard ratio for recurrent stroke: 0.11, 95% CI: 0.02–0.46; hazard ratio for death: 0.24, 95% CI: 0.08–0.75). Conclusion: Statin pretreatment in patients with acute LAA appears to be associated with better early outcomes regarding neurologic improvement, disability, survival, and stroke recurrence.