Thomas Meinel, MD

Jung YH, Kim YD, Kim J, Han SW, Oh MS, Lee JS, Lee K-Y. Initial Stroke Severity in Patients With Atrial Fibrillation According to Antithrombotic Therapy Before Ischemic Stroke. Stroke. 2020;51:2733–2741.

Direct oral anticoagulants (DOAC) have proven at least equally effective in the prevention of acute ischemic stroke in patients with atrial fibrillation as compared to the vitamin K antagonists (VKA). They are recommended in stroke prevention for DOAC-eligible atrial fibrillation patients (without moderate-to-severe mitral stenosis or mechanical heart valve) as the oral anticoagulation of choice since their net clinical benefit arises mainly from a reduced risk of intracranial hemorrhage.^1,2 Despite a significant reduction of stroke risk,¹ recurrent ischemic stroke in patients on DOACs still occurs with an estimated rate of 1-2% per year.³ The randomized controlled trials did not report exact data on the stroke severity in patients on DOACs. Real-world data are conflicting, limited by arbitrary dichotomization of stroke severity scores, and mostly did not look at laboratory assessment of DOAC activity or information on compliance.^4–8

In the August 2020 issue of Stroke, Jung et al. used a prospective, multicenter, hospital-based national stroke registry in Korea to evaluate trends of antithrombotic medication use in 6786 stroke patients with atrial fibrillation recruited between 2008 and 2018. The study aim was to explore the association between preceding antithrombotic medication use and initial stroke severity. 4009 patients were candidates for anticoagulation defined by a CHA2DS2-VASc score ≥2 and ATRIA score ≤4 prior to the acute ischemic stroke event. Among those, the overall prevalence of anticoagulation use was 27% and increased from 25% in 2010 to 41% in 2018 (P<0.001). Whereas the percentage of patients on VKA decreased in the recent years, the fraction of patients suffering ischemic stroke on DOACs increased from 4% in 2015 to 25% in 2018. Authors also found that stroke severity was higher in patients who were not on antithrombotics compared to those on antiplatelets or anticoagulants (median NIHSS: 8 versus 7 versus 6, P<0.001). Anticoagulation was also independently associated with mild stroke severity defined as NIHSS ≤5 (adjusted odds ratio, 1.31 [95% CI, 1.15–1.50]). However, there was no difference between antiplatelet agents and anticoagulation in terms of stroke severity.

Francesca Tinelli, MSc

Hirano Y, Miyawaki S, Imai H, Hongo H, Ohara K, Dofuku S, Teranishi Y, Nakatomi H, Saito N. Association Between the Onset Pattern of Adult Moyamoya Disease and Risk Factors for Stroke. Stroke. 2020;51:3124–3128.

Moyamoya angiopathy (MA) is a rare cerebrovascular disease characterized by chronic and progressive stenosis of the terminal part of the internal carotid arteries, associated with the compensatory development of an unstable vascular network (MA vessels).

Despite MA pathogenesis being unknown, an increasing number of studies propose alterations in angiogenesis and vasculogenesis as potential disease mechanisms. Moreover, the strong association with variants of Ring Finger Protein 213 (RNF213) gene in East Asian patients strengthens the role of genetic factors in MA pathogenesis.

Andy Lim, MBA, FACEM, GAICD
@ALim0211

Xiong Y, Bath PM. Antiplatelet Therapy for Transient Ischemic Attack and Minor Stroke. Stroke. 2020;51:3472–3474.

Another landmark has been reached to inform the early management of transient ischemic attack (TIA) and minor stroke. If you have not heard already, the THALES (Acute STroke or Transient IscHaemic Attack Treated With TicAgreLor and ASA for PrEvention of Stroke and Death) trial has recently hit the stroke scene. THALES was an international randomized controlled trial that found that early dual antiplatelet therapy (DAPT) for TIA and minor stroke (aspirin + ticagrelor) was superior to aspirin alone in the prevention of recurrent stroke or death.

Xiong and Bath pave the way forward in their recent review article in this field. The authors have pointed out three important points that have not remained answered, and therefore, directions for future research. First, exclusion of patients eligible for reperfusion therapy makes these findings less generalizable to this subgroup. Second, the optimal duration of aspirin + ticagrelor has not yet been established, and more information is required regarding bleeding rates as a function of time. Third, using aspirin as a control arm may no longer be the most relevant comparator, and aspirin + ticagrelor and aspirin + clopidogrel are yet to be compared.

Ammad Mahmood, MBChB
@AMahmoodNeuro

Kaesmacher J, Maamari B, Meinel TR, Piechowiak EI, Mosimann PJ, Mordasini P, Goeldlin M, Arnold M, Dobrocky T, Boeckh-Behrens T, et al. Effect of Pre- and In-Hospital Delay on Reperfusion in Acute Ischemic Stroke Mechanical Thrombectomy. Stroke. 2020;51:2934–2942.

Following the onset of vessel occlusion, the progressive detriment in the effectiveness of therapy is known and the mantra of “time is brain” is imbedded in the delivery of stroke pathways. Reducing door-to-needle, admission-to-groin (ATG), and symptom-to-admission (STA) times requires robust public health messaging, efficient pre-hospital care, and streamlined inpatient pathways. Analysis of the HERMES data suggested that prolonged ATG times were associated with reduced chances of achieving reperfusion. However, symptom-onset-to-groin (STG) times were not found to have a significant effect on reperfusion, though this was attributed to strict inclusion criteria for the HERMES trials.

In this study, real-world data from the BEYOND-SWIFT registry studied the effect of ATG, STA and STG on the likelihood of reperfusion in 2386 patients, of whom 2008 (84%) had successful reperfusion (TICI 2b-3). There was a small reduction in chance of successful reperfusion with increasing STA (aOR 0.97 [0.94–0.99] per hour). There was a stronger relationship between increasing ATG with reduced chance of successful reperfusion, aOR, 0.87 [0.79–0.96] per hour, meaning a 13% reduced chance of successful reperfusion with each hour of increase in ATG time. STG time was also significantly related, but this effect was attributed to the ATG time period.

Kevin O’Connor, MD

Sun LR, Harrar D, Drocton G, Castillo-Pinto C, Felling R, Carpenter JL, Wernovsky G, McDougall CG, Gailloud P, Pearl MS. Mechanical Thrombectomy for Acute Ischemic Stroke: Considerations in Children. Stroke. 2020;51:3174–3181.

Although there are no evidence-based guidelines for the use of mechanical thrombectomy (MT) in children with acute ischemic stroke, trials in adult and limited pediatric studies currently guide decision making. Several unique aspects of the pediatric stroke population warrant attention when considering MT.

There is no randomized controlled trial (RCT) comparing intravenous tPA plus MT to MT alone in children. Additionally, dosing for IV tPA in children is based on adult data and the Thrombolysis in Pediatric Stroke (TIPS) study, which was stopped before the needed number of patients was enrolled due to slow recruitment. Various analyses of data from adults shows no significant difference between MT alone and IV tPA plus MT, although one meta-analysis found a tendency toward lower modified Rankin Scale scores (0-2) at 90 days with IV tPA plus MT. Administration of IV tPA to children prior to MT can be considered if they are otherwise candidates for a thrombolytic.