American Heart Association

Monthly Archives: July 2018

Use of DWI-FLAIR Mismatch for IV-tPA: Results from the WAKE UP Trial

Gurmeen Kaur, MBBS

Thomalla G, Simonsen CZ, Boutitie F, Andersen G, Berthezene Y, Cheng B, et al. MRI-Guided Thrombolysis for Stroke with Unknown Time of Onset. NEJM. 2018

Recently, the impressive results of the MRI-Guided Thrombolysis trial, popularly known as WAKE UP, were announced at the European Stroke Organization Conference 2018.

In an investigator initiated, multicenter, randomized, double blind, placebo controlled clinical trial, patients waking up with stroke or those with undetermined last known well because of aphasia and confusion were included between 18-80 years of age.

All patients included did not have contraindications to getting IV tPA, but did not qualify because of the unclear LKW. Previous studies have determined that at the 4.5-hour mark, roughly estimating, the DWI shows positivity but the FLAIR does not show parenchymal involvement. Hence, the mismatch between DWI and FLAIR was used to screen and select patients to be divided into 2 groups: one that received alteplase and the other group that received placebo. Interestingly, patients that qualified for mechanical thrombectomy were excluded from this trial.

By |July 30th, 2018|clinical|0 Comments

Role of Combined Clopidogrel and Aspirin in High-Risk TIA and Stroke: Discussing the POINT Trial

Shashank Shekhar, MD, MS

Johnston SC, Easton JD, Farrant M, Barsan W, Conwit RA, Elm JJ, et al. Clopidogrel and Aspirin in Acute Ischemic Stroke and High-Risk TIA. N Engl J Med. 2018

The long-anticipated POINT trial has recently been presented at the 4th European Stroke Organization Conference 2018, and subsequently published in NEJM, in May 2018. After the CHANCE trial, many centers started using dual antiplatelet for lacunar strokes and TIA; there remained uncertainty over the validity of the non-Chinese population. The POINT trial results add validity to the five-years-old questions since the CHANCE trial.

The POINT trail is a multinational, randomized, placebo-controlled trial. The patients were assigned in 1:1 ratio between treatment and control arm. The treatment arm in the trial received a loading dose of 600mg Clopidogrel, followed by daily 75mg with daily aspirin (50mg-325mg). The control arm received same range of daily Aspirin with Placebo. The trial enrolled 4881 patients at 269 international sites in 10 different countries.

Blood Pressure During Thrombectomy: More Insights from SIESTA

Kat Dakay, DO

Schönenberger S, Uhlmann L, Ungerer M, Pfaff J, Nagel S, Klose C, et al. Association of Blood Pressure With Short- and Long-Term Functional Outcome After Stroke Thrombectomy: Post Hoc Analysis of the SIESTA Trial. Stroke. 2018

Now that mechanical thrombectomy for acute ischemic stroke has become a well-established treatment, the focus has become how best to manage patients peri-intervention.

As the authors mentioned, two major questions keep arising: What mode of sedation is best for patients undergoing thrombectomy? And, what is the ideal blood pressure goal to maintain before, during, and after intervention?

On the one hand, hypotension in the acute phase of stroke could theoretically lead to hypo-perfusion of the ischemic penumbra, leading to expansion of infarct. On the other hand, it is known that hypertension can increase the risk of intracerebral hemorrhage in patients who receive IV tPA [1], and it is unclear if this could translate to endovascular reperfusion as well. The optimal blood pressure for patients peri-intervention is not known.

No Cessation of Anticoagulants in Patients with Mild Acute Ischemic Strokes? A Post-hoc Analysis from the Preventive Antibiotics in Stroke Study

Aristeidis H. Katsanos, MD, PhD

Groot AE, Vermeij J-DM, Westendorp WF, Nederkoorn PJ, van de Beek D, Coutinho JM. Continuation or Discontinuation of Anticoagulation in the Early Phase After Acute Ischemic Stroke. Stroke. 2018

Stroke clinicians frequently are confronted with the dilemma of not only weighting the thrombembolic risk to the risk of bleeding in acute ischemic stroke (AIS) patients with indication for anticoagulation, but they should also decide the optimal timing for anticoagulation resumption. Even though numerous studies have investigated so far the optimal timing of anticoagulation resumption in AIS patients, no study has directly compared anticoagulant continuation (without cessation) to discontinuation in patients suffering an AIS while on anticoagulation.

Article Commentary: “Comparison of Risk Factor Control in the Year After Discharge for Ischemic Stroke Versus Acute Myocardial Infarction”

Bahar M. Beaver, MD

Bravata DM, Daggy J, Brosch J, Sico JJ, Baye F, Myers LJ, et al. “Comparison of Risk Factor Control in the Year After Discharge for Ischemic Stroke Versus Acute Myocardial Infarction.” Stroke. 2018

Stroke patients universally receive stroke education as part of their inpatient stay following their stroke. This education typically covers risk factors of stroke and expected outcomes, and emphasizes post-stroke lifestyle modifications (medication compliance, diet, and exercise) for secondary prevention. Once patients leave the hospital, compliance with these measures varies greatly. Current literature supports continued close follow-up in order to support patients as they implement these lifestyle modifications. One simple modification with which physician office staff can assist patients is medication compliance. More diligent medication compliance and close follow-up can lead to tighter control of vascular risk factors.

New Benchmark to Measure Angiographic Success of Recanalization in Ischemic Stroke Patients Undergoing Thrombectomy

Muhammad Zeeshan Memon, MD

Zaidat OO, Castonguay AC, Linfante I, Gupta R, Martin CO, Holloway WE, et al. First Pass Effect: A New Measure for Stroke Thrombectomy Devices. Stroke. 2018

Currently, the American Heart Association/American Stroke Association recommends mechanical thrombectomy as the standard of care for acute stroke patients with proximal artery occlusions. Multiple studies have shown complete or near-complete reperfusion achieved in a timely manner leads to improved clinical outcomes and reduced adverse effects; however, complete reperfusion is achieved in <50% of cases, and often requires many thrombectomy attempts and the use of multiple devices. This not only delays time to achieve recanalization, but also incurs additional risk of vessel spasm, injury, and rupture. Design improvement of mechanical thrombectomy devices, particularly the advent of stent retrievers, has improved recanalization rates and decreased the complication rates leading to this notion that achieving complete revascularization with a single pass should be the new angiographic goal.

Thrombectomy in Acute Stroke with TANdem Lesions: TITANic Technical Challenge?

Robert W. Regenhardt, MD, PhD

Gory B, Piotin M, Haussen DC, Steglich-Arnholm H, Holtmannspötter M, Labreuche J, et al. Thrombectomy in Acute Stroke With Tandem Occlusions From Dissection Versus Atherosclerotic Cause. Stroke. 2017

The revolution of acute stroke care, with the 2015 trials demonstrating superiority of endovascular thrombectomy (ET) compared to tPA alone and the subsequent DAWN and DEFUSE 3 trials extending its time window, has raised many questions about which patients will experience net benefit from this powerful therapy. Certainly, some vessel occlusions are more amenable to ET than others, but should the presence of technically difficult occlusions, with perhaps higher procedural risks, limit eligibility? Though poorly represented, patients with anterior circulation tandem lesions, involving both the cervical internal carotid artery (ICA) and an intracranial artery, experienced similar benefits as those with isolated intracranial occlusions in the HERMES meta-analysis. It is unclear if the etiology of tandem lesions predicts outcomes, if etiology should influence the decision to undergo ET, or if it should influence the procedural approach.

The two most common etiologies of tandem lesions are carotid atherosclerosis and carotid dissection. Treatment typically occurs in two phases: management of the cervical ICA lesion by stenting, angioplasty, both, or medical treatment alone, and management of the intracranial occluded vessel by stent retriever or direct aspiration first pass technique. The order of these phases remains controversial, with some centers starting with the intracranial lesion as stent retrievers only require a small microcatheter for deployment. Stenting versus angioplasty of the cervical ICA can be debated based on adequacy of collaterals, risk of reperfusion injury, risk of immediate dual antiplatelet therapy, and other individualized factors.

Article Commentary: “Hyperintense Plaque on Intracranial Vessel Wall Magnetic Resonance Imaging as a Predictor of Artery-to-Artery Embolic Infarction”

Richard Jackson, MD

Wu F, Song H, Ma Q, Xiao J, Jiang T, Huang X, et al. Hyperintense Plaque on Intracranial Vessel Wall Magnetic Resonance Imaging as a Predictor of Artery-to-Artery Embolic Infarction. Stroke. 2018

Despite the prevalence of symptomatic intracranial stenosis, there has been little progress into biomarkers that may identify patients at the highest risk of stroke recurrence. This article attempts to find an imaging biomarker for symptomatic intracranial atherosclerotic plaques.

From a prospectively enrolled MCA infarct population, a retrospective analysis was undertaken in a small cohort of 74 Asian patients with symptomatic intracranial stenosis of the middle cerebral artery (MCA). Whole brain high resolution pre and post-contrast magnetic resonance imaging (MRI) was used to evaluate MCA plaques. Patients were divided into A-to-A and non-A-to-A embolic infarction groups based on MR diffusion-weighted imaging infarct patterns. Patients with a previous history of stroke or transient ischemic attack on the symptomatic side, history of ipsilateral MCA or internal carotid artery occlusion, significant occlusion or plaque on the ipsilateral extra-cranial internal carotid artery, non-atherosclerotic vasculopathy and risk factors for cardiac embolism were excluded. Quantitative data were analyzed using t-test and chi squared testing. Hyperintense plaques (HIP) were more frequently observed in the A-to-A embolism group (75% versus 21.1%; p<0.001). In the A-to-A embolism patients, two thirds of HIPs were located adjacent to the lumen and one third of HIPs were located within the plaque (Figure 1).

Different types of hyperintense plaques (HIPs) and plaque surface. High-resolution magnetic resonance imaging (HRMRI) demonstrated HIPs with hyperintense areas (arrow) located adjacent to the lumen (A)/within the plaque (B) and irregular (C)/regular (D) plaque surface (arrowhead).

Figure 1. Different types of hyperintense plaques (HIPs) and plaque surface. High-resolution magnetic resonance imaging (HRMRI) demonstrated HIPs with hyperintense areas (arrow) located adjacent to the lumen (A)/within the plaque (B) and irregular (C)/regular (D) plaque surface (arrowhead).

Article Commentary: “Multivessel Occlusion in Patients Subjected to Thrombectomy”

Mohammad Anadani, MD

Kaesmacher J, Mosimann PJ, Giarrusso M, El-Koussy M, Zibold F, Piechowiak E, et al. Multivessel Occlusion in Patients Subjected to Thrombectomy: Prevalence, Associated Factors, and Clinical Implications. Stroke. 2018

Endovascular treatment is the standard of care for patients with acute ischemic stroke secondary to large vessel occlusion. It is not uncommon for patients with large vessel occlusion to present with multivessel occlusion (MVO). In the aforementioned study, the authors aimed to investigate prevalence, associated factors and outcome of MVO.

The authors retrospectively reviewed a prospective registry of patients who presented to comprehensive stroke center between 2012 and 2017 and had angiography with an intention for endovascular treatment. Initial diagnostic workup including CTA and MRA were evaluated by a neuroradiologist to diagnose MVO. A follow-up whole brain digital subtraction angiography (DSA) images were reviewed to confirm MVO.  Downstream MVO was defined as a second occlusion within the territory of and distal to the primary occlusion.

Post-Stroke Seizures in Relation to Age, Race, and Stroke Subtype

Kristin Miller, MD

Merkler AE, Gialdini G, Lerario MP, Parikh NS, Morris NA, Kummer B, et al. Population-Based Assessment of the Long-Term Risk of Seizures in Survivors of Stroke. Stroke. 2018

Post-stroke seizures are a well-described potential complication of stroke. However, the long-term risk of seizures in stroke survivors in relation to the characteristics of stroke subtypes and demographics has not been fully explored. Authors Merkler et al endeavored to explore this particular long-term risk in a large, multistate retrospective review using administrative claims data and Medicare claims data.

Using ICD-9 codes from multistate claims data for ischemic stroke, intracerebral hemorrhage (ICH), and subarachnoid hemorrhage (SAH), the investigators identified 777,276 patients who were hospitalized with an index stroke. Among those patients, 45,708 (5.88%) developed a new seizure with an annual incidence of 1.68% in the all-stroke group compared to 0.15% in the general population. The annual incidence of seizures and the cumulative rate of seizures were highest in ICH subtypes. Younger patients (<65 years) and nonwhite patients were more likely to develop seizures after stroke. A similar pattern was seen when analyzing Medicare beneficiary claims data in 81,984 patients; however, there was no difference in the annual incidence of post-stroke seizure based on race and no analysis was performed on age (due to the age of Medicare patients).