American Heart Association

Monthly Archives: August 2021

Does Thrombus Equal Thrombus? Mechanical Characterization of Thrombi Retrieved During Endovascular Thrombectomy in Stroke Patients

Tolga D. Dittrich, MD

Boodt N, Snouckaert van Schauburg PRW, Hund HM, Fereidoonnezhad B, McGarry JP, Akyildiz AC, van Es ACGM, De Meyer SF, Dippel DWJ, Lingsma HF, et al. Mechanical Characterization of Thrombi Retrieved With Endovascular Thrombectomy in Patients With Acute Ischemic Stroke. Stroke. 2021;52:2510–2517.

Mechanical thrombectomy (MT) for acute stroke has made remarkable advances over the last few years. Despite technological improvements, revascularization still is not successful in a considerable fraction of treated patients. This inevitably raises the question of why MT is so difficult in some patients and how we might treat them better in the future.

An important starting point could be a more comprehensive understanding of the biological composition of thrombi and their mechanical properties. Experimental studies have shown that increasing thrombus stiffness is associated with unsuccessful or incomplete recanalization. For example, particularly stiff platelet-rich thrombi could not be removed by aspiration alone or combined with a stent retriever in an animal model.

Medication Adherence Poststroke/TIA: Does Every Missed Dose Matter?

Ammad Mahmood, MBChB

Dalli LL, Kim J, Cadilhac DA, Greenland M, Sanfilippo FM, Andrew NE, Thrift AG, Grimley R, Lindley RI, Sundararajan V, et al. Greater Adherence to Secondary Prevention Medications Improves Survival After Stroke or Transient Ischemic Attack: A Linked Registry Study. Stroke. 2021.

Previous studies of medication adherence poststroke have used an arbitrary cut off of 80% adherence as signifying good adherence, with even 30-40% adherence considered to be “intermediate.” In this retrospective registry study, clinical data from the Australian Stroke Clinical Registry was linked with nationwide prescription refill and mortality data. Rather than focus on a cut-off, the authors utilized “restricted cubic spline” Cox regression to study the effect of a spectrum of adherence on outcome. They focused on adherence to antihypertensives, statins and non-aspirin antithrombotic agents amongst patients during the first year after first ever stroke or TIA and its link with all-cause mortality up to 3 years post-hospital discharge.

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

Estimating Residual Flow With Thrombus Perviousness and its Effect on Outcome in LVO Stroke

Vignan Yogendrakumar, MD, MSc

Kappelhof M, Tolhuisen ML, Treurniet KM, Dutra BG, Alves H, Zhang G, Brown S, Muir KW, Dávalos A, Roos YBWEM, et al. Endovascular Treatment Effect Diminishes With Increasing Thrombus Perviousness: Pooled Data From 7 Trials on Acute Ischemic Stroke. Stroke. 2021.

In the context of large vessel occlusion stroke, a growing number of advanced imaging studies are showing us that no two occlusions are alike. The imaging features of a thrombus can provide critical information that can inform us about the effectiveness of a given therapy. For example, the INTERRSeCT study published in 2018 showed that distal thrombus location and increased thrombus permeability were associated with increased rates of spontaneous recanalization with IV thrombolysis.

In this study, Kappelhof and colleagues utilize data from the HERMES dataset to assess thrombus permeability and determine its effect on clinical outcomes in patients who received EVT compared to those who received thrombolysis alone. The authors refer to permeability as “thrombus perviousness” and measured this by co-registering non-contrast CT (NCCT) and single-phase CTA images together and measuring the attenuation increase between NCCT and CTA images (Figure 2). The primary clinical outcome of the study was an ordinal analysis of the mRS.

Figure 2. Thrombus attenuation
increase measurement.
Figure 2. Thrombus attenuation increase measurement.

Tenecteplase for Thrombolysis of Acute Ischemic Stroke: The Debate Continues

Ammad Mahmood, MBChB

Putaala J, Saver JL, Nour M, Kleindorfer D, McDermott M, Kaste M. Should Tenecteplase be Given in Clinical Practice for Acute Ischemic Stroke Thrombolysis? Stroke. 2021;52:3075–3080.

Guaranteed to feature on the program at this year’s stroke meetings (virtual or otherwise), the debate regarding the potential use of tenecteplase for thrombolysis in acute ischemic stroke rolls on. The authors of this commentary present an excellent summary of the pros and cons of choosing tenecteplase over alteplase, summarizing and critiquing the evidence base in both camps, before reaching a balanced conclusion reflecting the current equipoise in the stroke community.

Evaluating Tranexamic Acid in Spot Sign Positive and Negative ICH Patients: An Analysis of the TICH-2 Trial

Vignan Yogendrakumar, MD, MSc

Ovesen C, Jakobsen JC, Gluud C, Steiner T, Law Z, Flaherty K, Dineen RA, Christensen LM, Overgaard K, Rasmussen RS, et al. Tranexamic Acid for Prevention of Hematoma Expansion in Intracerebral Hemorrhage Patients With or Without Spot Sign. Stroke. 2021;52:2629–2636.

While occurring less frequently than its ischemic counterpart, hemorrhagic stroke (intracerebral hemorrhage [ICH]) is a dynamic disease associated with higher degrees of morbidity and mortality. Approximately a third of acute ICH patients will experience growth of their baseline hemorrhage. This phenomenon, termed hematoma expansion, is associated with worsened long-term clinical outcomes. Hemostatic therapies have been extensively trialed, in hopes of limiting hematoma expansion and improving functional outcomes.

In 2018, the TICH-2 trial evaluated tranexamic acid against placebo in patients with acute ICH presenting within 8 hours of symptom onset. The trial showed a modest reduction in hematoma expansion incidence but no clear effect on long-term functional outcome.

In a pre-planned analysis of the TICH-2 trial, Ovesen and colleagues assessed whether there is a treatment interaction in ICH patients based on their spot sign status. The spot sign is a contrast-based marker seen in a proportion of ICH patients and is generally associated with a higher risk of hematoma expansion. The authors hoped to assess whether patients who are spot sign positive benefit more with tranexamic acid treatment compared to patients who are spot sign negative. The authors used either CT angiography or contrast-enhanced CTs to assess spot sign status. No constraints on scanner setting or protocol were placed. A central laboratory, blinded to treatment outcomes, assessed spot sign status using a widely adopted methodology. Outcomes assessed by the authors included intraparenchymal hematoma expansion (>6 mL or 33%), intraventricular hemorrhage expansion (> 2mL), and 90-day clinical outcomes based on the modified Rankin Scale.

By |August 25th, 2021|clinical|0 Comments

Article Commentary: “Predictors of Outcomes in Patients With Mild Ischemic Stroke Symptoms: MaRISS”

Dixon Yang, MD

Romano JG, Gardner H, Campo-Bustillo I, Khan Y, Tai S, Riley N, Smith EE, Sacco RL, Khatri P, Alger HM, et al, on behalf of the MaRISS Investigators. Predictors of Outcomes in Patients With Mild Ischemic Stroke Symptoms: MaRISS. Stroke. 2021;52:1995–2004.

Acute ischemic stroke commonly presents with mild or improving symptoms,1 often defined as minor stroke with NIHSS ≤ 5. Many of these patients are not treated with acute thrombolytic therapy due to exclusion from the landmark NINDS recombinant tissue-type plasminogen activator efficacy trials.2 Despite perceived minor symptoms, many of those hospitalized may be unable to walk independently or return directly to home at discharge.3 Effects of thrombolysis and long-term outcomes in minor stroke are still not well understood. Thus, Romano and colleagues sought to describe multidimensional long-term outcomes in patients with mild ischemic stroke symptoms from MaRISS (Mild and Rapidly Improving Stroke Study).

This prospective observational study recruited sites who participated in Get With The Guidelines-Stroke, had more than 300 annual stroke discharges, and reflected regional and national representation of hospital centers. Eligible MaRISS participants presented within 4.5 hours from stroke symptoms onset, had a brain CT excluding non-ischemic causes, and initial NIHSS of 0-5. Those with pre-morbid disability of mRS ≥2 or with complete resolution of symptoms on initial evaluation were excluded. The primary outcome was an mRS score of 0-1 at 90 days post-event. Secondary outcomes included Barthel Index 95-100 versus <95, Stroke Impact Scale-16 (SIS-16) ≥88.2 versus <88.2, and European Quality of Life 5D-5L 1 versus <1 and its visual analogue scale ≥90 versus <90.

Excess Leisure Sedentary Time and Risk of Stroke

Setareh Salehi Omran, MD

Joundi RA, Patten SB, Williams JVA, Smith EE. Association Between Excess Leisure Sedentary Time and Risk of Stroke in Young Individuals. Stroke. 2021.

Leisure sedentary time is increasing in the western world, particularly among young adults. While the association between physical activity and lower risk of stroke is well-known, data is limited on the association between sedentary time and stroke. It is also unclear whether an association between sedentary time and stroke can be modified with higher levels of physical activity.

Joundi et al. used a large cohort of healthy individuals from the nationwide Canadian Community Health Survey (CCHS) with linked administrative records to determine whether excess leisure sedentary time was associated with elevated long-term risk of stroke. The CCHS represents 97% of the Canadian household population and collects health-related information, including self-reported sedentary time and baseline covariates. The authors used nine cycles of the CCHS to identify healthy individuals >40 years of age without prior stroke, heart disease, or cancer history. Information was only available on sedentary time that was spent for leisure (not school- or work-related) and was categorized as <4 hours, 4 to <6 hours, 6 to <8 hours, and ≥8 hours/day.

By |August 19th, 2021|clinical|0 Comments

Antiseizure Drug Prophylaxis in Acute Ischemic Stroke

Ayush Agarwal, DM

Jones FJS, Sanches PR, Smith JR, Zafar SF, Hernandez-Diaz S, Blacker D, Hsu J, Schwamm LH, Westover MB, Moura LMVR. Anticonvulsant Primary and Secondary Prophylaxis for Acute Ischemic Stroke Patients: A Decision Analysis. Stroke. 2021.

Poststroke seizures are classified into early seizures and late seizures based on the time of occurrence with regards to the stroke. Seizures occurring within the first 7 days are classified as early seizures. Guidelines for the management of poststroke seizures are unclear due to the lack of adequate randomized clinical trials. Therefore, management mostly remains uncertain and “expert opinion” based. The newer generation of antiseizure drugs (ASD) with their comparatively better safety and adverse effect profiles tempt physicians to prescribe them as primary preventive therapy on the premise that they are relatively low-risk. Secondary prophylaxis for early seizures is also debated, with some advocating for not treating early seizure since they were likely to fall into the acute symptomatic seizure category. Late seizures are thought to arise from an anatomical substrate and are always treated with ASDs. However, the duration of treatment with ASDs for secondary prophylaxis is also contentious, with some advocating for a short treatment duration compared to lifelong therapy.

In this decision analysis study, adult patients with an index ischemic stroke were categorized into one of three treatment strategies: (a) long-term primary prophylaxis (ASDs lifelong); (b) short-term secondary prophylaxis following early seizures (for one week after the stroke event), with lifelong treatment if late seizures occurred; and (c) long-term secondary prophylaxis following early seizures (ASDs lifelong). The main outcome of the study was quality-adjusted life-years (QALY).

By |August 18th, 2021|clinical|0 Comments

Article Commentary: “Stroke Hospitalizations Before and During COVID-19 Pandemic Among Medicare Beneficiaries in the United States”

Nurose Karim, MD

Yang Q, Tong X, Coleman King S, Olivari BS, Merritt RK. Stroke Hospitalizations Before and During COVID-19 Pandemic Among Medicare Beneficiaries in the United States. Stroke. 2021.

The year 2020 will be remembered as one of the most challenging years in the history of medicine due to the novel SARS COVID-19 pandemic. The “new normal” had its impact on many lives and the economy of the country.

Stroke is the fifth leading cause of death in the United States. Each year, nearly 800,000 Americans have a new or recurrent stroke (on average 15,000 strokes per week), and approximately 150,000 die, accounting for 1 in 20 deaths in the United States. Early treatment is critical for better outcome. Due to the COVID-19 pandemic, there were statewide stay-in-home orders that led to delay in seeking care for stroke victims.

By |August 17th, 2021|clinical|0 Comments

How to Help the Fast Progressor? A Review of “Mobile Interventional Stroke Teams Improve Outcomes in the Early Time Window for Large Vessel Occlusion Stroke”

Yasmin Aziz, MD

Morey JR, Zhang X, Fares Marayati N, Matsoukas S, Fiano E, Oxley T, Dangayach N, Stein LK, Fara MG, Skliut M, et al. Mobile Interventional Stroke Teams Improve Outcomes in the Early Time Window for Large Vessel Occlusion Stroke. Stroke. 2021.  

In modern medicine, there is only a small subset of physicians who travel with their respective team to spoke locations acutely for intervention. Here, the neurointervention team at Mount Sinai in New York City flipped the table on the traditional drip and ship (DS) model of patient transfer by doing just that. 

In this study, the authors assess whether time from last known well (LKW) influences the success of their Mobile Interventional Stroke Teams (MIST) model compared to the traditional DS model. To review, the results of their earlier study, “The NYC MIST Trial,” showed the MIST model to be superior to conventional triage models in terms of faster groin puncture times and patient outcomes. 

By |August 16th, 2021|clinical|1 Comment