American Heart Association

Monthly Archives: August 2018

Article Commentary: “Effects of Blood Pressure in the Early Phase of Ischemic Stroke and Stroke Subtype on Poststroke Cognitive Impairment”

Kara Jo Swafford, MD

He M, Wang J, Liu N, Xiao X, Geng S, Meng P, et al. Effects of Blood Pressure in the Early Phase of Ischemic Stroke and Stroke Subtype on Poststroke Cognitive Impairment. Stroke. 2018

Poststroke cognitive impairment (PSCI) is common, having a prevalence between 24% and 58% at 3 months following the acute event. Symptoms can range from mild cognitive impairment to severe dementia and is associated with higher morbidity and mortality. Patient demographics, vascular risk factors and stroke subtypes may help predict development of PSCI.

Hypertension is an important factor that increases the risk for PSCI by causing cerebrovascular dysautoregulation, leading to impaired cortical function. Hypotension can also worsen prognosis, leading to impairment of cognition by reducing cerebral blood flow. This suggests a U-shaped relationship between blood pressure and stroke outcome. Regulation of blood pressure is vital for cerebral perfusion and preventing further neuronal injury. This is why identifying the optimal blood pressure range becomes important in the early phase after ischemic stroke. There is, however, no clear consensus on optimal blood pressure levels to reduce the risk of PSCI. There are also little data on how stroke subtypes relate to PSCI.

By |August 31st, 2018|clinical|0 Comments

IV-tPA and Mechanical Thrombectomy – A Winning Team

Kevin S. Attenhofer, MD
@KAttenhofer

Ferrigno M, Bricout N, Leys D, Estrade L, Cordonnier C, Personnic T, et al. Intravenous Recombinant Tissue-Type Plasminogen Activator: Influence on Outcome in Anterior Circulation Ischemic Stroke Treated by Mechanical Thrombectomy. Stroke. 2018

2015 was a big year for stroke. For the first time in 20 years, stroke practitioners demonstrated an effective tool in the treatment of acute ischemic stroke. Mechanical thrombectomy (MT) quickly became standard practice. While MT was proposed as an adjunctive therapy for stroke in addition to IV-rtPA (IVT), many of the 2015 trials, as well as the subsequent imaging based trials (DAWN, DEFUSE 3), included patients who did not receive IVT.

The benefit of MT was similar in patients who received IVT and MT compared to MT alone in some trials. This has led some to suggest that MT alone could be a treatment option which maximizes potential benefit while minimizing some of the risks associated with IVT (such as hemorrhage). In fact, I’ve seen non-neurology physicians advocate for MT to replace IVT entirely. Still, others argue that IVT facilitates MT (higher rate of successful recanalization, shorter procedures, and shorter time to recanalization) as well as dissolving distal clots. To date, no randomized controlled trial has compared combination IVT/MT versus MT alone. A recent meta-analysis of the 2015 thrombectomy trials seems to support the latter view: that IVT and MT are complimentary.

Review on Decision-Making in Patients with PFO

Richard Jackson, MD

Saver JL, Mattle HP, Thaler D. Patent Foramen Ovale Closure Versus Medical Therapy for Cryptogenic Ischemic Stroke: A Topical Review. Stroke. 2018

This is a much-needed review on the topic of patent foramen ovale (PFO) closure to help guide physician decision-making in cryptogenic stroke in the young adult. The finding of a PFO in a young or middle-aged ischemic stroke patient is a common clinical dilemma which now has data to guide physician treatment decisions. Three new trials — RESPECT, REDUCE, and CLOSE — in 2017 have added new research into our understanding of the role of PFO in ischemic stroke.

The article begins with a review of the epidemiology of PFO. In the general population, PFOs are present in 20-25% of individuals. In cryptogenic stroke, the prevalence is 50-60%, which translates to a 2.3 fold increased relative risk. The authors theorize through probability theory that PFO is, therefore, causative in the mechanism of stroke in 73% of patients with cryptogenic stroke and incidental in 23% of patients with cryptogenic stroke.

By |August 27th, 2018|clinical|0 Comments

Hyperintense Plaque: Biomarker for Symptomatic Carotid Disease

Hatim Attar, 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

In recent years, a lot of interest has been generated on understanding plaque morphology and identifying plaques that are truly symptomatic. Various newer imaging modalities and techniques coupled with knowledge of basic histopathology of plaques has placed researchers in a position to answer these questions. Analyzing plaques, and being able to determine which ones are actually the problem, is a focus not only of vascular neurology, but also of cardiology. Thus, several joint efforts with pooling of carotid and coronary plaques have provided a rapid growth in literature in the last few years. This study has looked specifically into intracranial Artery to Artery (A to A) subtype of embolic strokes and used Whole Brain High Resolution MRI (WB- HRMRI) to investigate plaque characteristics.

By |August 24th, 2018|clinical|0 Comments

Clot Aspiration and Stent Retriever are Equally Effective Regardless of Clot Burden

Mohammad Anadani, MD

Zhu F, Lapergue B, Kyheng M, Blanc R, Labreuche J, Machaa MB, et al. Similar Outcomes for Contact Aspiration and Stent Retriever Use According to the Admission Clot Burden Score in ASTER. Stroke. 2018

Despite the overwhelming evidence supporting the benefit of mechanical thrombectomy in acute stroke treatment, the best thrombectomy technique is still unknown. The ASTER trial (Contact Aspiration Versus Stent Retriever for Successful Recanalization) was a prospective, multicenter, randomized trial that compared contact aspiration technique with stent retriever and showed no difference in the rate of successful recanalization and clinical outcome between two techniques. However, a question remained on what is the optimal approach for patients with large intracranial clot burden.

To address this question, Zhu and his colleagues underwent a post-hoc analysis of the ASTER trial comparing contact aspiration with stent retriever according to the intracranial clot burden. Clot burden was measured using the clot burden score (CBS). The CBS is a scoring system to measure the extent of anterior circulation thrombus and is scored on a scale from 0-10. A score of 10 indicates clot absence, and a score of 0 indicates complete multisegment vessel occlusion.

By |August 22nd, 2018|clinical|0 Comments

Rate of Successful Recanalization in Extended Time Windows is Similar to Early Treatment Windows

Muhammad Zeeshan Memon, MD

Marks MP, Heit JJ, Lansberg MG, Kemp S, Christensen S, Derdeyn CP, et al. Endovascular Treatment in the DEFUSE 3 Study. Stroke. 2018

Recently, two trials demonstrated that the benefit of endovascular thrombectomy extended beyond 6 hours to up to 24 hours after last seen well in selected patients. The DEFUSE 3 trial (Endovascular Therapy Following Imaging Evaluation for Ischemic Stroke 3) was a randomized study comparing medical therapy to endovascular treatment plus medical therapy 6 to 16 hours after last known well, and DAWN (DWI or CTP Assessment With Clinical Mismatch in the Triage of Wake-Up and Late Presenting Strokes Undergoing Neurointervention With Trevo) was a multicenter, prospective, randomized trial comparing medical treatment with Trevo stent retriever. Before these trials, there is very limited about effectiveness of thrombectomy beyond 6 hours.

By |August 20th, 2018|clinical|0 Comments

Distal Vessel Thrombectomy: Should We Treat Smaller Vessel Occlusions?

Robert W. Regenhardt, MD, PhD
@rwregen

Grossberg JA, Rebello LC, Haussen DC, Bouslama M, Bowen M, Barreira CM, et al. Beyond Large Vessel Occlusion Strokes: Distal Occlusion Thrombectomy. Stroke. 2018

For large vessel occlusion (LVO) strokes, endovascular thrombectomy (ET) has become the standard of care. Given the demonstrated efficacy and low number needed to treat for this powerful therapy, there is impetus to push the envelope on inclusion criteria. In terms of time, the recent DAWN and DEFUSE 3 trials have prompted most institutions to consider patients up to 24 hours since last seen well. In addition to pushing the time window, others are investigating the safety and efficacy of targeting vessels that are smaller and more distal than the carotid and proximal middle cerebral arteries (MCA). Indeed, some distal occlusions can result in significant neurologic deficits, especially if they are upstream of eloquent cortex such as distal MCA occlusions resulting in aphasia. Moreover, newer devices allow interventionalists access to these smaller distal vessels. Several studies have suggested a benefit of M2 segment ET, showing improved outcomes and similar rates of reperfusion. However, a large meta-analysis of 1080 patients with M2 occlusions showed there was an increased risk of hemorrhage compared to M1 occlusions.

This study by Grossberg et al published in the July issue of Stroke sought to examine the safety and efficacy of distal ET at their single center. Retrospectively, they identified 69 patients with distal occlusions treated with ET from 2010-2015. They defined distal occlusions as involving anterior cerebral arteries (ACA), posterior cerebral arteries (PCA), or MCA distal to the M3 opercular segment. 42% received intravenous (IV) tPA, and the median NIHSS score was 18. For 45 patients, the distal occlusion was the primary treatment; for 23 patients, the distal occlusion was a rescue treatment after a different primary LVO. Primary treatments were of the M3 (n=21), ACA (n=8), ACA and M1/M2 (n=10), ACA and M3 (n=3), and PCA (n=3). Rescue treatments were of the M3 (n=11), ACA (n=7), PCA (n=4), and M3 and ACA (n=1).

By |August 17th, 2018|clinical|0 Comments

Microbiology of Pneumonia in Patients with Stroke

Andrea Morotti, MD

Kishore AK, Vail A, Jeans AR, Chamorro A, Di Napoli M, Kalra L, et al. Microbiological Etiologies of Pneumonia Complicating Stroke: A Systematic Review. Stroke. 2018 

Pneumonia is a common medical complication in subjects suffering acute stroke and is independently associated with poor functional outcome. In this paper, Dr. Kishore and colleagues described the microbiological etiology of pneumonia in stroke patients through a systematic review of the available literature.

A total of 7968 subjects included in 15 studies were analyzed. The authors reported notable variability in the rate of pneumonia (2% to 63%), and the majority of patients (78%) developed this complication within one week from stroke onset. Sputum culture was the most common method to obtain biological samples for culture, whereas a minority of patients underwent tracheal aspirate or blood culture (15% and 20%, respectively). There was also significant heterogeneity in the prevalence of positive cultures (15% to 88%), and the following pathogens were more commonly identified: Klebsiella pneumoniae (12.8%), Escherichia coli (9%), Staphylococcus aureus (10.1%). Interestingly, Streptococcus Pneumoniae was identified in only 3.5% of cases.

By |August 15th, 2018|clinical|0 Comments

How Should We Best Treat M2 Occlusions?

Kat Dakay, DO 

Saber H, Narayanan S, Palla M, Saver JL, Nogueira RG, Yoo AJ, et al. Mechanical thrombectomy for acute ischemic stroke with occlusion of the M2 segment of the middle cerebral artery: a meta-analysis. J Neurointerv Surg. 2018

While the data is more straightforward on the benefit of treating proximal large vessel occlusions such as the M1 or the internal carotid artery with mechanical thrombectomy, M2’s are less certain. The endovascular trials published in 2014 underrepresented M2 occlusions: SWIFT PRIME, ESCAPE and REVASCAT excluded M2 occlusions, whereas MR CLEAN and EXTEND IA had a few M2 occlusions included in their study populations [1].

The concerns about potential risks of treating M2 occlusions are understandable: M2 occlusions would theoretically have less penumbral tissue compared to M1 occlusions, and they may be more likely than proximal occlusions to recanalize with IV tPA [2]. There is a concern about procedural risks as well: Some believe that the narrow lumen diameter and thinner vessel wall may predispose to procedural complications [3]. On the other hand, the recanalization effect of tPA may be overestimated, with one series only demonstrating 6% recanalization with tPA alone [4]. Additionally, the natural history of M2 occlusions can be debilitating, with two retrospective studies of untreated patients showing that about half of patients being functionally dependent [5, 6] with even worse outcomes occurring in left M2 occlusions.

By |August 13th, 2018|clinical|0 Comments

Antiplatelet in Patients with Microbleeds: Prevent Ischemic Stroke or Precipitate Hemorrhage?

Qing Hao, MD

Lau KK, Lovelock CE, Li L, Simoni M, Gutnikov S, Küker W, et al. Antiplatelet Treatment After Transient Ischemic Attack and Ischemic Stroke in Patients With Cerebral Microbleeds in 2 Large Cohorts and an Updated Systematic Review. Stroke. 2018

With the recent advance in image techniques, MRI has helped tremendously in understanding the mechanism of cerebrovascular disease. “The more you know, the more you know you don’t know” (Aristotle). When patients not only have a TIA or ischemic stroke, but also cerebral microbleeds (CMB), what should we do with the antiplatelet agent?

Aiming to find some solutions for this treatment dilemma, Lau, Lovelock and colleagues prospectively studied 2156 patients with diagnosis of TIA/ischemic stroke from two large cohorts in the United Kingdom and Hong Kong, respectively, to study the risks and time course of recurrent ischemic events, ICH/extracranial hemorrhage stratified by microbleeds burden.

By |August 10th, 2018|clinical|1 Comment