American Heart Association

Monthly Archives: April 2019

Diagnostic and Treatment Approach of Cervico-Cephalic Intraluminal Thrombus

Sami Al Kasab, MD

Singh R-J, Chakraborty D, Dey S, Ganesh A, Al Sultan AS, Eesa M, et al. Intraluminal Thrombi in the Cervico-Cephalic Arteries: Clinical-Imaging Manifestations, Treatment Strategies, and Outcome. Stroke. 2018;50:357–364.

With the increased imaging of the head and neck vasculature as part routine stroke/TIA workup, diagnosis of intraluminal thrombus (ILT) has become more common. The presence of ILT in the cervico-cephalic vasculature in patients with TIA or stroke poses a diagnostic and therapeutic challenge. In this study, Singh et al. report the clinical and imaging manifestation of ILT and provide recommendations on therapeutic options. The study was conducted at the University of Calgary. Patients with suspected TIA or stroke between April 2015 and September 2017 were included in these analyses. Diagnosis of ILT was made by CTA of the head and neck performed routinely on admission, which was evaluated by a neuroradiologist, once the diagnosis of ILT was made, it was confirmed by a second neuroradioloigst.

A total of 3750 patients were evaluated during the study period; ILT was identified in 61 patients (1.6%). Median age was 67 years (IQR, 56-73); 40 (65.6%) patients were men. Patients with ILT had high prevalence of hypertension, smoking and dyslipidemia (47.5%, 44.3%, and 41% respectively). The most common presentation was ischemic stroke (80.3%), and most strokes were mild with median NIHSS of 2 (IQR, 1-4). The most common location of ILT was extracranial internal carotid artery (65.6%), followed by extracranial vertebral artery (11.2%). The most common cause of ILT was atherosclerosis in the affected artery (82 %) manifested by ulcerated plaque with or without luminal stenosis. Ulcerated plaque was identified in 6.6% of patients only. 51/61 (83.6%) were found to have ≥50% underlying stenosis, arterial dissection was identified in 6.6% of cases and 1 patient (1.6%) had cardio-embolic etiology.

By |April 12th, 2019|clinical|0 Comments

Antiplatelet Therapy in Stroke: The Old and the New

Alan C. Cameron, MB ChB, BSc (Hons), MRCP

Hackam DG, Spence JD. Antiplatelet Therapy in Ischaemic Stroke and Transient Ischaemic Attack. Stroke. 2019; 50:773–778.

Antiplatelet therapy reduces the burden of recurrent vascular events in patients with non-cardioembolic ischaemic stroke or TIA and the authors present an overview of major trials.  The IST and CAST studies, conducted over 20 years ago, highlight the benefits of aspirin in the acute setting and the benefits of aspirin in the longer term are demonstrated by the Antithrombotic Trialists’ Collaboration.  It was later shown that aspirin and dipyridamole in combination is more effective than aspirin alone, with most data coming from the ESPS-2 and ESPRIT studies, although dipyridamole requires twice daily dosing and many patients develop headache.  The PRoFESS trial shows rates of recurrent stroke are similar with clopidogrel compared to aspirin and dipyridamole, although clopidogrel has once-daily dosing and fewer patients develop headache.

The landmark CHANCE and POINT trials demonstrate that DAPT with clopidogrel and aspirin reduces the risk of stroke and vascular events in patients with high-risk TIA or minor stroke compared to aspirin alone and the benefit is confined to the early period.  This may explain why longer-term trials of DAPT (MATCH, SPS3 and CHARISMA) found no benefit. The SOCRATES trial found that DAPT with ticagrelor and aspirin is not superior to aspirin in reducing vascular events, although ticagrelor shows a strong trend toward reduced stroke in the acute setting and is more efficacious in patients with large artery disease or patients already taking aspirin.  The THALES trial is studying ticagrelor in this context and will help to better define the role of ticagrelor in acute stroke. Importantly, we can reduce the risk of haemorrhage associated with antiplatelet therapy by effectively managing bleeding risk factors, including blood pressure control, treatment of Helicobacter pylori infection and proton pump inhibitors for high risk patients.

Is Endovascular Thrombectomy Safe and Effective in Large Vessel Occlusion Patients with ASPECTS 0-5: Time to Rethink?

Ravinder-Jeet Singh, MBBS, DM

Kaesmacher J, Chaloulos-Iakovidis P, Panos L, Mordasini P, Michel P, Hajdu SD, et al. Mechanical Thrombectomy in Ischemic Stroke Patients With Alberta Stroke Program Early Computed Tomography Score 0-5. Stroke. 2019;50:880-888.

Early and successful reperfusion leads to favourable outcome among patients with stroke having intracranial large artery occlusion. However, restoring blood flow to an infarcted tissue has a potential to induce reperfusion injury-related complications manifesting by development of malignant edema, intracerebral hemorrhage (ICH) or both. The risk is greater among those with larger pre-treatment infarct size, which is frequently defined using low ASPECTS scores (<6) or large cores (for example, >70-100 ml) on blood-flow imaging (CT/MR perfusion). Due to safety concerns, these patients were excluded from recent endovascular thrombectomy (EVT) trials. Contrary to general perception, recent literature demonstrates good safety of EVT in these patients and work by Kaesmacher et al1 is further addition to EVT safety and efficacy data in this group.

From a multicenter registry (BEYOND-SWIFT; N=2046), authors identified 237 patients who had ASPECTS 0-5 and underwent EVT. Overall, nearly equal proportion of patients had favorable outcome (mRS 0-3) and death (40.1% and 40.9%, respectively). Obviously, these patients had lower rates of favorable outcome than the group with ASPECTS 6-10 (40.1 vs 61.2%; P<0.001) and also had higher mortality (40.9 vs 21.2%; P<0.001), however, authors demonstrated no safety concerns of EVT with respect to rates of symptomatic ICH (7.2% vs 6.0%; P=0.466). The effect on all outcomes was clearly influenced by achievement of the successful reperfusion (TICI 2b/3), presence of which resulted in higher rates of favorable outcome, lower mortality and lower symptomatic ICH rates. On further inspection of the data, functional benefits were predominantly observed in ASPECTS 5 patients, nonetheless, mortality benefits were still observed in those with further lower ASPECTS scores (4 or even 0-3 group) when successful reperfusion was achieved.  Patients with ASPECTS 0-5 had longer procedure duration (groin puncture to reperfusion), lower successful reperfusion rates and higher frequency of procedural complications during EVT than ASPECTS 6-10 patients. Larger clot burden and higher cervical artery dissection rates leading to procedural challenges might be few of the explanations for this observation.

Intervening on Interventions in Endovascular Stroke Treatment

Raffaele Ornello, MD

Janssen PM, Venema E, Dippel DWJ. Effect of workflow improvements in endovascular stroke treatment: A systematic review and meta-analysis. Stroke. 2019;50:665–674.

Acting fast is of key importance to ensure the success of endovascular treatment (EVT) for ischemic stroke. While the available evidence already showed that workflow interventions improve the time to treatment with intravenous rtPA, the effect of workflow interventions on EVT is less clear. In their systematic review and meta-analysis, the authors included 51 studies referring to workflow interventions in EVT, including anesthetic management, pre-hospital management, in-hospital transfer management, teamwork, and feedback. Overall, each single intervention resulted in a significant improvement of time to EVT, with a mean value of 26 minutes and up to 64 minutes for feedback interventions.

Although limited by the large contribution of retrospective data and by the low availability of pre-hospital management data, the published systematic review and meta-analysis underlines the importance and effectiveness of planning adequate EVT workflow intervention in clinical practice to improve the treatment time of ischemic stroke and patient outcomes.

What’s Behind Childhood Arterial Ischemic Stroke?

Alejandro Fuerte, MD
@DrFuerte1

McCrea N, Fullerton HJ, Ganesan V. Genetic and Environmental Associations With Pediatric Cerebral Arteriopathy: Insights Into Disease Mechanisms. Stroke. 2019;50:257–265.

Childhood arterial ischemic stroke (AIS) occurs by interaction between rare genetic risk factors and common environmental exposures. In this article, McCrea et al. expose these mechanisms relying mainly on the results of the VIPS study (Vascular Effects of Infection in Paediatric Stroke).

Genetic Associations

From a genetic point of view, it is important to highlight moyamoya arteriopathy and Neurofibromatosis type 1 (NF1). Moyamoya is a rare artery disease that consists of a progressive stenosis of the internal carotid artery and its main branches. Children with moyamoya are at risk of AIS, whereas adults are more prone to haemorrhagic stroke. NF1 is an autosomal dominant tumour-suppressor syndrome, caused by mutations in the gene encoding for neurofibromin, a RAS pathway inhibitor (chromosome 17). Children with NF1 have an increased risk of stroke, with odds ratios of 8.1 for haemorrhagic stroke and 3.4 for AIS.

Cerebral Amyloid Angiopathy and Disruption of the Blood-Brain Barrier

Kara Jo Swafford, MD

Freeze WM, Bacskai BJ, Frosch MP, Jacobs HIL, Backes WH, Greenberg SM, et al. Blood-Brain Barrier Leakage and Microvascular Lesions in Cerebral Amyloid Angiopathy. Stroke. 2019;50:328–335.

Cerebral amyloid angiopathy (CAA) is characterized by amyloid-b (Ab) deposition within walls of small to medium sized arteries, arterioles and capillaries in the cerebral cortex and leptomeninges. It is observed in approximately 33% of the general aged population and 90% of those with Alzheimer’s disease. CAA can lead to cerebral microbleeds (CMBs) and cerebral microinfarcts (CMIs), as well as cerebral atrophy, structural network disruption and cognitive decline. In the elderly, CAA is the most common cause of lobar intracerebral hemorrhage.

Freeze et al performed a postmortem study to investigate the role of blood-brain barrier (BBB) disruption in CAA-related brain injury, hypothesizing that BBB leakage is associated with CAA severity and is present predominantly in parietooccipital regions because of CAA’s predilection for affecting blood vessels in these regions. Eleven CAA confirmed cases were compared to 7 controls without neurological disease. BBB disruption was measured by plasma protein (fibrin, IgG) extravasation in the cortex. CAA severity was graded based on presence of Aβ. Microvascular lesions (CMBs, CMIs) were assessed using histopathology and MRI.

Basilar Artery Stenting: When Remodeling Predicts Stroke

Elena Zapata-Arriaza, MD
@ElenaZaps

Ma N, Xu Z, Lyu J, Li M, Hou Z, Liu Y, et al. Association of Perforator Stroke After Basilar Artery Stenting With Negative Remodeling. Stroke. 2019;50:745–749.

Basilar artery (BA) is more frequently associated to positive remodeling; however, the opposite may also occur. Negative remodeling due to intracranial atherosclerotic disease involves a narrowing in the vessel lumen and is related to higher stroke risk. However, the information about remodeling pattern and its influence in stroke risk after angioplasty and stenting is scarce.

To answer the question, the authors studied patients with symptomatic intracranial arterial stenosis who were assessed with high-resolution magnetic resonance imaging (HRMRI) from September 2014 to January 2017. Among them, patients with BA stenosis who underwent angioplasty and stenting were recruited. Arterial remodeling patterns were divided into negative or nonnegative (positive and intermediate remodeling) remodeling according to remodeling index. (Remodeling index ≥1.05 was defined as positive remodeling, 0.95 and 1.05 as intermediate remodeling, and ≤0.95 as negative remodeling.) Plaque features were investigated by HRMRI. Incidence of perforator strokes after intracranial stenting was collected. Plaque features and incidence of post stenting perforator stroke were compared between negative and nonnegative remodeling.