Aurora Semerano, MD
@semerano_aurora

Ganji M, Nardi V, Prasad M, Jordan KL, Bois MC, Franchi F, Zhu XY, Tang H, Young MD, Lerman LO, Lerman A. Carotid Plaques From Symptomatic Patients Are Characterized by Local Increase in Xanthine Oxidase Expression. Stroke. 2021.

Investigating mechanisms of plaque instability is needed to better treat patients with carotid atherosclerosis. In parallel, the search for reliable biomarkers, including blood parameters and imaging features, is required to identify patients with carotid plaques at the highest risk of embolism. Within this effort of providing new knowledge in the field, this study¹ recently published in Stroke aimed at investigating the histological characteristics of plaque instability. The authors were specifically interested in exploring the role of xanthine oxidase, the enzyme that catalyzes the synthesis of uric acid, which acts as an indicator of oxidative homeostasis and has been previously associated with atherosclerosis and increased cardiovascular risk.²

The study examined 88 randomly selected carotid artery specimens from symptomatic (within the previous 6 months) and asymptomatic patients. No difference was observed in the relative percentage of traditional histological components of atherosclerosis (such as fibrosis, plaque hemorrhage, calcium, and lipid core). The amount of macrophage infiltration was also comparable between specimens from symptomatic and asymptomatic patients. Interestingly, the authors found significantly higher expression of xanthine oxidase in symptomatic carotid plaques. Further, in a subset of 27 samples, they observed that percentage of macrophages expressing xanthine oxidase was increased in symptomatic plaques. Moreover, xanthine oxidase expression in the plaques positively correlated with uric acid levels in the blood.

Melanie R. F. Greenway, MD
@MRFGreenwayMD

Dearborn-Tomazos JL, Hu X, Bravata DM, Phadke MA, Baye FM, Myers LJ, Concato J, Zillich AJ, Reeves MJ, Sico JJ. Deintensification or No Statin Treatment Is Associated with Higher Mortality in Patients With Ischemic Stroke or Transient Ischemic Attack. Stroke. 2021.

Optimizing statin therapy in patients after stroke or TIA is an important component of secondary stroke prevention. High-intensity statin and LDL-C goal <70 mg/dL are the two main targets for secondary stroke prevention based on SPARCL¹ and TST.² The recent “2021 Guideline for the Prevention of Stroke in Patients with Stroke and Transient Ischemic Attack”³ recommends atorvastatin 80mg daily in patients with ischemic stroke, no known coronary artery disease, no major cardiac source of embolism, and LDL-C > 100mg/dL. In those with ischemic stroke or TIA who have evidence of atherosclerotic disease, LDL-C lowering to <70mg/dL is recommended with statin and, if needed, ezetimibe, though a specific dose or intensity of statin is not specified. 

This study looked at 10,871 patients with a primary diagnosis of acute ischemic stroke or TIA who presented to the ER or were admitted during the fiscal year of 2011 at 134 VA centers across the United States. After excluding those who were transferred out of the VA system, died during hospitalization, left against medical advice, were discharged to hospice, or allergic to statins, 9,380 patients were left for review. Their cohort of patients was 96.3% male, 71.1% White, and 34.9% smokers. The mean age was 68.7.

Juan Carlos Martinez Gutierrez, MD
@JCMartinezMD

Langezaal LCM, van der Hoeven EJRJ, Mont’Alverne FJA, de Carvalho JJF, Lima FO, Dippel DWJ, van der Lugt A, Lo RTH, Boiten J, Lycklama À Nijeholt GJ, et al. Endovascular Therapy for Stroke Due to Basilar-Artery Occlusion. N Engl J Med. 2021:384:1910-1920.

Langezaal et al. published results on the BASICS study in the NEJM. This study was an international randomized open-label blinded outcome trial comparing standard medical management (MM) versus Endovascular Thrombectomy (EVT) for Basilar Artery Occlusions (BAO).

They recruited patients aged <85 years with BAO within 6 hours of symptoms onset, National Institutes of Health Stroke Scale score (NIHSS) >10, and no large established infarct (i.e., bilateral brainstem, cerebellar infarct with mass effect or hydrocephalus). The trial was initially powered to detect a 10% difference between arms based on available evidence from the BASICS registry, which showed favorable functional outcome (modified Rankin Score [mRS] 0-3) in 40% of participants treated with EVT and in 30% of those treated with MM. This initial design required 750 patients; however, after 4 years of slow recruitment and new evidence of EVT benefit in the anterior circulation, the trial was redesigned. The new assumption was that treatment effect may be higher based on the positive 2015 EVT trials, so the expected mRS 0-3 rate was increased to 46% for the EVT arm. The 16% risk reduction resulted in a smaller sample size estimation of 300. In addition, to increase potential recruitment, the eligibility criteria was expanded to include patients aged >85 years, those with NIHSS <10 and those with contraindications for intravenous thrombolysis.

Tolga D. Dittrich, MD

Kamel H, Parikh NS, Chatterjee A, Kim LK, Saver JL, Schwamm LH, Zachrison KS, Nogueira RG, Adeoye O, Díaz I, et al. Access to Mechanical Thrombectomy for Ischemic Stroke in the United States. Stroke. 2021.

Mechanical thrombectomy (MT) helps prevent disability in patients with acute ischemic stroke due to large vessel occlusion. However, MT is not offered by every hospital since its performance requires special technical expertise. A key factor for functional outcome in the context of MT is the duration between symptom onset and successful recanalization. Therefore, the goal of acute stroke care is to avoid time loss, whether due to long transport to an MT-capable center or delayed diagnostic workups to detect a stroke whenever possible. Kamel et al. examined whether current systems of stroke care in the United States provide adequate access to MT.

From 2016 to 2018, discharge data from all nonfederal emergency departments and acute care hospitals in 11 U.S. states were examined. Hospitals were categorized according to their ability to provide MT as follows: (a) hubs (if they were able to perform MT); (b) gateways (if they referred patients who ultimately underwent MT); and (c) gaps (otherwise). Of 205,681 patients with ischemic stroke, 48.7% received care in a hub, 35.3% in a gateway, and 16.0% in an MT gap. Rural patients had particularly limited access, with 27.7% of these patients initially receiving care at hubs compared with 69.5% of urban patients. Thrombolysis could be initially performed in 93.8% of patients at gateways compared with 76.3% of patients at gaps. A substantial proportion of ischemic stroke patients in the U.S. did not have access to MT, even after accounting for interhospital transfers.