American Heart Association

Is There a Magic Number for Thrombectomy Retrieval Attempts?

Melanie R. F. Greenway, MD

Flottmann F, Brekenfeld C, Broocks G, Leischner H, McDonough R, Faizy T, Deb-Chatterji M, Alegiani A, Thomalla G, Mpotsaris A, et al. Good Clinical Outcome Decreases With Number of Retrieval Attempts in Stroke Thrombectomy: Beyond the First-Pass Effect. Stroke. 2021;52:482-490.

Between discussion of the “First Pass Effect”1,2 and wondering “When to Stop,”3 finding a magic number of retrieval attempts that optimizes potential good outcome and minimizes risk of adverse events continues to be an important clinical question. 

Utilizing the German Stroke Registry-Endovascular Treatment section, the authors focused on reviewing number of retrieval attempts as it correlates with final TICI score and modified Rankin Score (mRS) at 90 days.  They analyzed 2611 patients from 2015-2018, 1225 of which met inclusion and exclusion criteria. All patients included were 18 years of age or older, underwent endovascular therapy of the intracranial anterior circulation, and had a complete set of data needed for the study. A successful reperfusion was defined as TICI 2b or 3, and a “good clinical outcome” was defined as mRS 0-2.

Should We Blame the Heart? Recurrent Ischemic Stroke in Patients With Atrial Fibrillation and Small Vessel Disease

Alejandro Rodríguez-Vázquez, MD

Du H, Wilson D, Ambler G , Banerjee G, Shakeshaft C, Cohen H, Yousry T, Al-Shahi Salman R, Lip GYH, Houlden H, et al. Small Vessel Disease and Ischemic Stroke Risk During Anticoagulation for Atrial Fibrillation After Cerebral Ischemia. Stroke. 2021;52:91–99.

Atrial fibrillation (AF) is one of the most important risk factors associated with ischemic stroke, with a 4.7 to 7.7%/year risk of cerebrovascular events despite anticoagulation. These recurrences could be explained because of an inadequate anticoagulation or alternative stroke mechanisms such as small vessel disease (SVD).

The authors analyzed data from the CROMIS-2 study, a multicenter prospective inception cohort study of patients anticoagulated for AF after an ischemic stroke or transient ischemic attack. They included 1419 patients with MR imaging and a total follow-up of 24 months after the first cerebrovascular event. SVD was present in 768 (54.1%) patients, defined as the presence of ≥11 basal ganglia perivascular spaces (BGPV), ≥11 centrum semiovale perivascular spaces, cerebral microbleeds, lacunes and/or moderate to severe white matter hyperintensities (which included periventricular Fazekas grade 3 or deep white matter Fazekas grade ≥2).

Expanding Access to Mechanical Thrombectomy

Kevin O’Connor, MD

Lopez-Rivera V, Salazar-Marioni S, Abdelkhaleq R, Savitz SI, Czap AL, Alderazi YJ, Chen PR, Grotta JC, Blackburn SL, Jones W, et al. Integrated Stroke System Model Expands Availability of Endovascular Therapy While Maintaining Quality Outcomes. Stroke. 2021;52:1022–1029.

Models of acute stroke care delivery, including for endovascular therapy (EVT), continue to evolve. Lopez-Rivera et al. piloted an integrated stroke system (ISS) in a large urban area that expanded EVT capabilities from an initial site to four EVT-capable hospitals. The ISS comprised a shared provider group, as well as a standardized management protocol. The primary endpoint was time from symptom onset to hospital arrival before and after implementation of the ISS. They also considered safety (postprocedural hemorrhage rate) and functional outcomes (good outcome defined as an mRS 0-2 at 90 days).

A total of 513 patients underwent EVT both pre- and post-ISS. Of these, primary endpoint evaluable data was available for the 352 patients (68.6%) who had a known time of symptom onset. There was a 40-minute decrease in time from known onset to hospital arrival compared to before the establishment of the ISS after adjusting for age and NIHSS (95% CI, 16–65, P<0.01). Among the 513 patients, there were decreases in both door to recanalization (153 versus 129 minutes, pre-ISS versus post-ISS, P<0.0001) and onset to groin puncture (229 versus 202 minutes, pre-ISS to post-ISS, P<0.05). Rates of procedural complications and good outcomes were comparable between the original EVT hospital and the three new sites included in the ISS. The reason that time of symptom onset was not known for 31% of the cohort was not explained and could be a source of bias.

Fibromuscular Dysplasia in Spontaneous Cervical Artery Dissection: A Hypothetical Question

Lukas Mayer, MD

Bonacina S, Grassi M, Zedde M, Zini A, Bersano A, Gandolfo C, Silvestrelli G, Baracchini C, Cerrato P, Lodigiani C, et al. Clinical Features of Patients With Cervical Artery Dissection and Fibromuscular Dysplasia. Stroke. 2021;52:821–829.

The search for characteristic features of underlying vasculopathy and/or connective tissue disease in patients with spontaneous cervical artery dissection has been going on for quite some time now, more recently yielding progress on multiple levels. Especially in vascular imaging, the coexistence of radiological hallmarks supposedly attributed to fibromuscular dysplasia (FMD) has been of interest in these subjects.

Through their recently published study, Bonacina et al. add to this interesting and highly relevant topic. The authors reviewed case files and imaging data of 1283 subjects enrolled in the multicenter Italian Project of Stroke in Young Adults Cervical Artery Dissection (IPSYS CeAD) study with the inclusion criterion being first-ever spontaneous cervical artery dissection (sCeAD) between January 2000 and June 2019. Through their work-up, they generated a cohort clinically consistent with most previously described sCeAD studies, as patients were in their mid 40s at sCeAD onset, males predominated, coexistent cerebrovascular risk factors were infrequent at baseline and cerebral ischemia was evident in more than 80% of sCeAD cases. Solely, the 60 to 40% split of internal carotid to vertebral artery affection might suggest an older sample of patients as more recent sCeAD-cohorts support an equal distribution of anterior and posterior circulation dissection. The latter has predominantly been attributed to the increased availability of advanced cerebrovascular imaging (e.g., 3T MRI – fat saturated T1 imaging). In 8% of subjects, according to the most recent expert consensus guidelines, vascular imaging was consistent with cerebrovascular FMD. Acute management and clinical manifestation did not differ in those with or without these signs. Subjects did, however, differ in some demographics and clinical characteristics, as those with imaging findings suggestive of FMD were more frequently women, more likely to have intracranial aneurysms and first-degree relatives with sCeAD. Upon follow-up, they also were more likely to have pseudoaneurysms, multivessel involvement of sCeAD and sCeAD recurrence. Bonacina et al. further describe pathophysiological mechanisms possibly linking migraine with aura, cerebrovascular FMD and sCeAD.

Brain’s Resident Immune Cells Gone Rogue: Impacts on Thalamic Degeneration After Stroke

Lin Kooi Ong, PhD

Cao Z, Harvey SS, Chiang T, Foltz AG, Lee AG, Cheng MY, Steinberg GK. Unique Subtype of Microglia in Degenerative Thalamus After Cortical Stroke. Stroke. 2021;52:687–698.

In my previous Blogging Stroke post, it is apparent that brain damage is not only confined to the primary infarction site after ischemic stroke, but also in remote regions of the brain. Indeed, secondary thalamic degeneration has been constantly observed in neuroimaging studies among stroke patients with cortical stroke as well as in experimental stroke models. While the mechanisms involved in the development of secondary thalamic degeneration have not been fully elucidated, studies suggest that neuroinflammation is most likely involved. Microglia are thought to be the primary resident immune cells of the brain mediating neuroinflammatory responses after stroke.

In this study, Cao and colleagues investigated the spatiotemporal changes of neurodegeneration, neuroinflammatory responses, and microglial activation for up to 84 days after experimental cortical stroke. They found that microglial activation occurred rapidly and preceded the progressive neuronal loss in the thalamus after stroke. Results from transcriptome analysis of the thalamus showed robust increase in the expression of neuroinflammation and microglia related genes. Excitingly, using a cell sorting technique, the team discovered a unique subtype of CD11c-positive microglia with disease-associated molecular profiles in the thalamus. These disease-associated microglia include reduced expression of Tmem119 and CX3CR1, and increased expression of ApoE, Axl, LpL, CSF1, and Cst7.

Expanding Knowledge of Pediatric ICH

Kevin O’Connor, MD

Boulouis G, Hak JF, Kerleroux B, Benichi S, Stricker S, Gariel F, Alias Q, Bourgeois M, Meyer P, Kossorotoff M, et al. Hemorrhage Expansion After Pediatric Intracerebral Hemorrhage. Stroke. 2021;52:588-594.

Intracerebral hemorrhage (ICH), similar to most aspects of pediatric stroke, is not as well-studied as it is in adults, in part due to its lower incidence in children. Boulouis et al. retrospectively assessed a cohort of pediatric ICH patients at a single center in Paris, France (2000-2019). Various exclusion criteria reduced their patient population from 243 to 52. Of these children, 18 had hemorrhage expansion (HE; 34.6%) and 8 of these had significant hemorrhage expansion (sHE; 15.4%). Children with sHE were more likely to have coagulation disorders (50.0% versus 2.3%; P=0.022) and tended to more frequently have focal deficits on presentation, although the difference was not significant (75.0% versus 43.2%; P=0.08). Underlying coagulation disorders were independently associated with any HE (adjusted OR, 14.4 [95% CI, 1.04–217]; P=0.048).

Outcomes were assessed using the King’s Outcome Scale for Childhood Head Injury (KOSCHI) score at 12 months. Scores <5 were poor, with scores of 2-3 reflecting severe disabilities, and score of 1 representing death. Just under half of the 52 children had a poor outcome (n=21, 40.4%) with 8 being severely disabled or dying (15.4%). Significant HE was associated with poor outcome in general (adjusted OR, 6.01 [95% CI, 0.91–39.82]; P=0.048) and with severe disability or death in particular (adjusted OR 21.71 [95% CI, 3.35–140.64]; P=0.001).

By |April 30th, 2021|clinical|0 Comments

Endovascular Stroke Therapy in the Extended Time Window: Beneficial Even in the Absence of Perfusion Imaging?

Tolga Daniel Dittrich, MD

Nogueira RG, Haussen DC, Liebeskind D, Jovin TG, Gupta R, Jadhav A, Budzik RF, Baxter B, Krajina A, Bonafe A, et al. Stroke Imaging Selection Modality and Endovascular Therapy Outcomes in the Early and Extended Time Windows. Stroke. 2021;52:491-497.

Perfusion imaging currently represents a key selection tool for endovascular therapy (EVT) in stroke patients with large vessel occlusions in the extended time window. However, the extent to which imaging modality influences clinical outcome in EVTs remains unclear in this context.

Nogueira et al. tackled this question by comparing the functional outcome of patients with intracranial carotid, M1-, or M2-occlusions of the middle cerebral artery with modified Rankin Scale score from 0 to 2 and time to treatment between early (i.e., 0-6 hours) and extended time windows (i.e., 6-24 hours) depending on the imaging modality received. These were either non-contrast computed tomography (NCCT)±CT angiography (CTA) or NCCT±CTA with CT perfusion (CTP).

Optimal Timing of Anticoagulation After Ischemic Stroke in Patients With Atrial Fibrillation?

Walter Valesky, MD

Labovitz AJ, Rose DZ, Fradley MG, Meriwether J, Renati S, Martin R, Kasprowicz T, Murtagh R, Kip K, Beck T, et al. Early Apixaban Use Following Stroke in Patients With Atrial Fibrillation: Results of the AREST Trial. Stroke. 2021;52:1164-1171.

In the era of direct oral anticoagulant (DOAC) therapy, a paucity of clinical trials exist guiding anticoagulation for atrial fibrillation (AF) after acute ischemic stroke (AIS). European Heart Rhythm Association guidelines promoted (by expert panel) a 1-3-6-12 day approach with anticoagulation started after 1 day in patients with a transient ischemic attack (TIA), after 3 days in those with small strokes, after 6 days in those patients with moderate strokes and approximately 2 weeks in those with large arterial distribution strokes.­1 Guidelines from the American Heart Association are extremely broad and recommend starting anticoagulation after 4-14 days in patients with ischemic stroke.2 Additionally, these recommendations are based on data that do not adequately reflect the current management of AF using DOACs.3 Labovitz et al. attempt to give clarity to this topic with an open-label, randomized trial to evaluate the safety of early use of apixaban in patients with recent stroke compared to warfarin. 

In the AREST trial, the authors enrolled patients with onset of symptoms of AIS or TIA within 3-5 days or within 3 days, respectively. These patients also had a history of AF or newly diagnosed AF confirmed using usual methods by an electrophysiologist. Once randomized, patients in the apixaban group were started on day 0-3 for TIA, day 3-5 for small-sized AIS (<1.5cm in largest dimension), and day 7-9 for medium-sized AIS (>1.5cm but less than a full vascular territory). Patients randomized to receive warfarin were started at 1-week post-TIA or 2 weeks post-stroke. Patients with large-sized AIS (entire vascular territory) and brainstem strokes were excluded. In addition, patients with obvious contraindications to anticoagulation use such as intracranial hemorrhage (ICH), hemorrhagic transformation, as well as those with AIS believed to be from non-embolic etiologies were excluded.

By |April 29th, 2021|clinical|0 Comments

The Role of Time and Collateral Status on Ischemic Core Overestimation on CT Perfusion

Tolga Daniel Dittrich, MD

García-Tornel Á, Campos D, Rubiera M, Boned S, Olivé-Gadea M, Requena M, Ciolli L, Muchada M, Pagola J, Rodriguez-Luna D, et al. Ischemic Core Overestimation on Computed Tomography Perfusion. Stroke. 2021.

Computed tomography perfusion (CTP) has become widely accepted as the imaging modality for the estimation of the infarct core and subsequent selection for endovascular treatment (EVT) in ischemic stroke due to large vessel occlusion (LVO), especially in the late time window. The radiological correlate for the core in CTP is usually the volume of tissue with a (compared with the contralateral hemisphere) reduction in cerebral blood flow (CBF) <30%. Overestimation of the core in CTP is thought to be time-dependent and may be a concern, especially with rapid imaging after symptom onset and fast reperfusion after imaging.

García-Tornel et al. addressed the question of the influence of time and collateral status on ischemic core overestimation. They retrospectively evaluated patients with anterior circulation LVO strokes with successful reperfusion after EVT. The core was considered to be the tissue with CBF <30% in CTP. Collateral status was assessed by the hypoperfusion intensity ratio (time to maximum of tissue residue function >6 seconds/time to maximum of tissue residue function >10 seconds). The reference for the final infarct volume was the non-contrast CT after 24 to 48 hours.

How Old is Too Old for a Statin?

Kevin O’Connor, MD

Lefeber GJ, Knol W, Souverein PC, Bouvy ML, de Boer A, Koek HL. Statins After Ischemic Stroke in the Oldest: A Cohort Study Using the Clinical Practice Research Datalink Database. Stroke. 2021;52:1244–1252.

Statins are a component of usual care following ischemic stroke, but evidence for their initiation in patients age >80-years is limited. Lefeber et al. conducted an observational cohort study to examine the effect of statin initiation on recurrence of cardiovascular events and mortality in those age >80-years following a first stroke. They performed the same analyses on patients aged 65-80 for comparison.

Patients ≥80 and 65-80 had reductions in cardiovascular events when prescribed statins for > 2 years (≥80 adjusted HR, 0.70 [95% CI, 0.52–0.92]; 65-80 adjusted HR, 0.67 [95% CI, 0.49–0.91]) compared to no statin use. There was no significant difference in event rates for either cohort when treated for 1-2 years compared to untreated patients (≥80 adjusted HR, 0.79 [95% CI, 0.59–1.07]; 65-80 adjusted HR, 1.00 [95% CI, 0.69–1.46]). Using a statin for less than one year was associated with reductions in both groups (≥80 adjusted HR, 0.43 [95% CI, 0.29–0.41]; 65-80 adjusted HR, 0.43 [95% CI, 0.34–0.54]). Compared to < 2 years of statin use (or no use), there was a nonsignificant trend toward lower risk for the ≥80 cohort (adjusted HR, 0.80 [95% CI, 0.62–1.02]) and a significant reduction in the 65-80 group (adjusted HR, 0.74 [95% CI, 0.57–0.96]) with use >2 years. Adjusted for mortality, the NNT to reduce cardiovascular events in the ≥80 group and the 65-80 group were 48.8 and 68, respectively.

By |April 28th, 2021|clinical|0 Comments