American Heart Association


Is There a Magic Number for Thrombectomy Retrieval Attempts?

Melanie R. F. Greenway, MD

Flottmann F, Brekenfeld C, Broocks G, Leischner H, McDonough R, Faizy T, Deb-Chatterji M, Alegiani A, Thomalla G, Mpotsaris A, et al. Good Clinical Outcome Decreases With Number of Retrieval Attempts in Stroke Thrombectomy: Beyond the First-Pass Effect. Stroke. 2021;52:482-490.

Between discussion of the “First Pass Effect”1,2 and wondering “When to Stop,”3 finding a magic number of retrieval attempts that optimizes potential good outcome and minimizes risk of adverse events continues to be an important clinical question. 

Utilizing the German Stroke Registry-Endovascular Treatment section, the authors focused on reviewing number of retrieval attempts as it correlates with final TICI score and modified Rankin Score (mRS) at 90 days.  They analyzed 2611 patients from 2015-2018, 1225 of which met inclusion and exclusion criteria. All patients included were 18 years of age or older, underwent endovascular therapy of the intracranial anterior circulation, and had a complete set of data needed for the study. A successful reperfusion was defined as TICI 2b or 3, and a “good clinical outcome” was defined as mRS 0-2.

Endovascular Stroke Therapy in the Extended Time Window: Beneficial Even in the Absence of Perfusion Imaging?

Tolga Daniel Dittrich, MD

Nogueira RG, Haussen DC, Liebeskind D, Jovin TG, Gupta R, Jadhav A, Budzik RF, Baxter B, Krajina A, Bonafe A, et al. Stroke Imaging Selection Modality and Endovascular Therapy Outcomes in the Early and Extended Time Windows. Stroke. 2021;52:491-497.

Perfusion imaging currently represents a key selection tool for endovascular therapy (EVT) in stroke patients with large vessel occlusions in the extended time window. However, the extent to which imaging modality influences clinical outcome in EVTs remains unclear in this context.

Nogueira et al. tackled this question by comparing the functional outcome of patients with intracranial carotid, M1-, or M2-occlusions of the middle cerebral artery with modified Rankin Scale score from 0 to 2 and time to treatment between early (i.e., 0-6 hours) and extended time windows (i.e., 6-24 hours) depending on the imaging modality received. These were either non-contrast computed tomography (NCCT)±CT angiography (CTA) or NCCT±CTA with CT perfusion (CTP).

Managing Tandem Occlusions From Carotid Dissection: To Stent or Not to Stent?

Setareh Salehi Omran, MD

Marnat G, Lapergue B, Sibon I, Gariel F, Bourcier R, Kyheng M, Labreuche J, Dargazanli C, Consoli A, Blanc R, et al. Safety and Outcome of Carotid Dissection Stenting During the Treatment of Tandem Occlusions: A Pooled Analysis of TITAN and ETIS. Stroke. 2020;51:3713–3718.

Intracranial occlusions with an ipsilateral cervical internal carotid artery (ICA) stenosis/occlusion, so-called tandem occlusions, are a frequent cause of anterior circulation strokes. Tandem occlusions can be treated with endovascular therapy, although the best technical strategy for treating the ICA stenosis/occlusion component is unclear.1 In particular, there is great variability in practice with performing carotid artery stenting (CAS) in addition to intracranial thrombectomy.2 It is also unknown whether the etiology of the ICA stenosis/occlusion, either from dissection or atherosclerosis, should impact the decision to perform CAS. While data supports thrombectomy with CAS in tandem occlusions due to atherosclerosis, there is limited data on its safety and efficacy in tandem occlusions from carotid dissection.3

Marnat et al4 examined the safety and outcome of CAS during the treatment of tandem occlusions from carotid dissections using pooled data from two prospectively maintained, multicenter databases (Endovascular Treatment in Ischemic Stroke and Thrombectomy in Tandem Lesion). The analysis included patients who received endovascular therapy for tandem occlusions related to acute cervical carotid dissection between January 2012 and January 2019. The endovascular strategy, stenting protocol, and antithrombotic regimens were chosen by the interventionalist and treating team. Patients were divided in two groups depending on whether they did or did not undergo CAS. The main outcomes of favorable neurological outcome (defined as 90-day mRS 0-2) and successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b-3) were assessed in both groups. The rates of procedural complications, 90-day mortality, and symptomatic intracerebral hemorrhage were also compared between patients who did and did not undergo CAS. In order to minimize potential bias due to endovascular strategy, the authors performed a sensitivity analysis comparing main clinical outcomes (favorable outcome and overall degree of disability) in the subgroup of patients with successful reperfusion.

Interventions for Medium Vessel Occlusions

Kevin O’Connor, MD

Pérez-García C, Moreu M, Rosati S, Simal P, Egido JA, Gomez-Escalonilla C, Arrazola J. Mechanical Thrombectomy in Medium Vessel Occlusions: Blind Exchange With Mini-Pinning Technique Versus Mini Stent Retriever Alone. Stroke. 2020;51:3224-3231.

Although mechanical thrombectomy (MT) is routinely performed for patients with acute stroke due to large vessel occlusions, interventions for those with medium vessel occlusions (MeVO) are increasing. Techniques for MT for MeVOs include the use stent retrievers and distal aspiration catheters (DACs). A recently developed approach is the blind exchange/mini-pinning (BEMP) technique, which combines a mini stent retriever with a DAC (see Figure 1 below).

Figure 1. Illustrations depicting the blind exchange with mini-pinning technique.
Figure 1. Illustrations depicting the blind exchange with mini-pinning technique.

Pérez-García et al. retrospectively compared mini stent retrievers alone (initial standard institutional MeVO procedure, n=50) versus the BEMP technique (later standard institutional MeVO procedure, n=56) for effectiveness and safety using a prospective database of MT patients. Aside from the DACs, the devices used for the two groups were comparable. The BEMP technique group had a higher rate of expanded Thrombolysis in Cerebral Ischemia (eTICI) 2c/3 recanalization scores after first pass (n=32, 57% versus n=17, 34%; P=0.017) and at procedure conclusion (n=37, 66% versus n=23, 46%; P=0.037). The rate of eTICI ≥ 2b recanalization scores was comparable between the groups after first pass (n=36, 64% versus n=25, 50%; P=0.137) and at procedure end (n=44, 78.5% versus n=39, 78%; P=0.856). A rescue therapy (other than the initial technique) was used less often in the BEMP group (n=4, 7.1% versus n=11, 22%; P=0.028). The BEMP technique was an independent predictor of eTICI 2c/3 recanalization (OR 2.72 [95% CI, 1.19-6.22]; P=0.018).

The Benefit of Targeting LDL Cholesterol <70 mg/dL Even at Expense of Adding Second Lipid-Lowering Agent

Manya Khrlobyan, DO, MS

Amarenco P, Kim JS, Labreuche J, Charles H, Giroud M, Lee BC, Mahagne MH, Nighoghossian N, Steg PG, Vicaut E, et al. Benefit of Targeting a LDL (Low-Density Lipoprotein) Cholesterol <70 mg/dL During 5 Years After Ischemic Stroke. Stroke. 2020;51:1231–1239.

The most recent American Heart Association/American Stroke Association guidelines recommend high intensity statin therapy for patients with ischemic stroke or TIA presumed to be of atherosclerotic origin and a Low-Density Lipoprotein (LDL) level >100 mg/dL. These recommendations are largely based on the results of the 2006 SPARCL trial (Stroke Prevention by Aggressive Reduction in Cholesterol Level). With these recommendations in mind, patients are typically started on Atorvastatin 80 mg daily, though often times without a specific LDL target in mind.

The TST trial (Treat Stroke to Target) was a randomized, event driven trial which investigated the benefit of targeting an LDL of <70 mg/dL in ischemic stroke patients in a French and Korean population to reduce the risk of cardiovascular events. Patients were eligible if they had an ischemic stroke <3 months previously or a TIA within the previous 15 days, atherosclerotic stenosis of cerebral vasculature (extra or intracranial), aortic arch plaque >4 mm, or known history of coronary artery disease. Patients were randomly assigned in a 1:1 ratio to target LDL of < 70 mg/dL or target LDL of 100 + 10 mg/dL. Investigators were free to use any type and dose of statin to reach the target LDL and, at 3 weeks follow-up, had an option of adjusting the statin dose or adding other lipid lowering agents such as ezetimibe to achieve the target LDL. The primary endpoint was the composite of ischemic stroke, myocardial infarction, need for carotid or coronary revascularization, and unexplained sudden death.

Local Anesthesia or Conscious Sedation in Mechanical Thrombectomy

Melanie R. F. Greenway, MD

Benvegnù F, Richard S, Marnat G, Bourcier R, Labreuche J, Anadani M, Sibon I, Dargazanli C, Arquizan C, Anxionnat R, et. al. Local Anesthesia Without Sedation During Thrombectomy for Anterior Circulation Stroke is Associated with Worse Outcome. Stroke. 2020;51:2951-2959.

As mechanical reperfusion therapy continues to advance, questions regarding procedural methods of anesthesia continue to arise.  This article compares functional outcomes in patients who received local anesthesia or conscious sedation for mechanical thrombectomy in acute ischemic stroke.

Utilizing the Endovascular Treatment in Ischemic Stroke Registry (ETIS) in France, the authors evaluated  1034 patients with large vessel occlusion admitted for mechanical thrombectomy from January to December 2018 at 4 centers. Three centers used a protocol with conscious sedation as the first-line treatment approach for mechanical thrombectomy, while one center used local anesthesia as the first-line treatment approach. After excluding patients because of missing information, absence of large vessel occlusion, or other exclusion criteria, 636 patients from the conscious sedation centers and 238 from the local anesthesia center were included in the intention-to-treat analysis. From there, 577 patients in the conscious sedation group and 185 patients from the local anesthesia group were included in the per-protocol analysis, as additional patients were excluded because of a change to their anesthesia management after enrollment. 

ISC 2021 Session: Treatment of Acute Stroke in Childhood and Young Adults (Debate)

Sishir Mannava, MD

International Stroke Conference 2021
March 17–19, 2021
Session: Treatment of Acute Stroke in Childhood and Young Adults (Debate) (179, On Demand)

This session began with Dr. Lisa Sun from Johns Hopkins School of Medicine presenting on brain attacks in teenagers, and that “we can best care for adolescents with stroke by organizing existing adult stroke centers to be able to treat teenagers.” Dr. Sun discussed how adult stroke centers and dedicated stroke units have better outcomes with organized stroke teams and stroke protocols. This leads to faster stroke recognition and treatment times. Dr. Sun presented data from time to imaging/diagnosis in major pediatric stroke centers after stroke protocol initiation, and, at best, the times appear to be between 1.3-1.6 hours, which is slower than the DTN times median of about 1 hour in adult stroke programs. Although primary pediatric stroke center development has been proven by the TIPS trial, Dr. Sun argued that it may not be feasible or resourceful to develop the needed amount of pediatric stroke centers to provide adequate coverage to all pediatric stroke populations.

“Endovascular therapy can be more safely and effectively administered to adolescents at an adult stroke center.” Dr. Sun discussed how thrombectomy in adolescents is technically like adult thrombectomy, and that by 5 years of age, head and neck arteries approach adult size. The common femoral artery (FA) sheaths used in adults can even be used in smaller adolescents as long as the ratio of FA size to catheter size is maintained, to avoid vasospasm. Adult stroke centers also have greater procedural experience, larger stock of devices, and higher volume of thrombectomies than pediatric thrombectomy centers. Data from the TRACK registry showed a significant difference in mRS ≥ 2 and final mTICI ≥2c-3 amongst higher volume centers as opposed to lower volume centers.

ISC 2021 Session: Tenecteplase Is Ready for Clinical Practice (Debate)

Saurav Das, MD

International Stroke Conference 2021
March 17–19, 2021
Session: Tenecteplase Is Ready for Clinical Practice (Debate) (183)

Whether tenecteplase (TNK) is ready for clinical practice is certainly one of the crucial questions faced by the stroke community today, especially in the changing landscape with emerging evidence for non-inferiority of direct thrombectomy compared to bridging recanalization treatment, the success of mobile stroke units (MSU), and our ability for pre-hospital treatment of patients within the golden hour of last known well. TNK is not a new drug. It is successfully used in treatment of myocardial infarction, and we have evidence from five randomized controlled trials (alluded to several times in the following debate) for non-inferiority compared to alteplase (tPA) in treatment of stroke. The nay-sayers do point to inherent issues with these trials and argue that we need more data. But the question is, how much longer is this wait going to be?

This debate was in 5 segments. In the first segment, Dr. Jeffrey Saver from the University of California, Los Angeles (UCLA) argued in favor of the motion. In the second segment, Dr. Patrick Lyden from Keck School of Medicine, University of South California, argued against the motion. In the third segment, both the speakers had an opportunity for rebuttal. In the fourth segment, Dr. Shelagh Coutts from the University of Calgary provided her balancing view. And in the final segment, Dr. Steven Warach from Dell School of Medicine, UT Austin, shared his practical experience with use of TNK for the past 15 months. The session was moderated by Dr. E. Clarke Haley Jr. from the University of Virginia, Charlottesville.

ISC 2021 Session: Challenging EVT Decision Making: When, Where, and Who to Treat (Debate)

Robert W. Regenhardt, MD, PhD

International Stroke Conference 2021
March 17–19, 2021
Session: Challenging EVT Decision Making: When, Where, and Who to Treat (Debate) (33, On Demand)

The session “Challenging EVT Decision Making: When, Where, and Who to Treat” (Debate) highlights some of the most difficult management decisions regarding EVT.

Dr. Sandra Narayanan built the case “Low NIHSS proximal occlusions should undergo thrombectomy.” She started by reviewing the magnitude of the question. An LVO is present in 18% of patients with NIHSS 0-4 and 39% of those with NIHSS 5-8. Furthermore, 15% of LVO stroke patients have minor symptoms. Deterioration can happen in early or delayed fashion; about 40% deteriorate early. Current guidelines suggest that treating patients with low NIHSS is reasonable. Indeed, several studies show a benefit. The Grady experience (JNIS 2017; 9:917-921) described 32 patients with NIHSS<6. Analyses of this cohort, while small, suggested a benefit of EVT. 22 were treated with medical management, of which 9 declined requiring EVT. The median time from arrival to deterioration was 5.2 hours. Subsequently, a larger study of 6 CSCs (Stroke 2018;49: 2391-2397) described 300 patients with NIHSS<6; 11.3% of those treated with medical management later declined. At 90 days, mRS 0-2 was observed in 84% of those treated with EVT, 70% of those with medical management, and 55% of those who underwent rescue EVT. Those who are allowed to deteriorate tend to have worse outcomes. The risks versus benefits should be carefully weighed up front because waiting more than 3 hours appears to impact outcomes. There is growing data that patients at risk for decline can be selected by collaterals, orthostatic challenges, perfusion imaging, and NIHSS eloquence/disability. Three randomized controlled trials are forthcoming: ENDOLOW, IN EXTREMIS, and TEMPO 2.

ISC 2021 Session: Mismatch Misalignments for Extended-window IV-thrombolysis for Non-Large Vessel Occlusion Strokes (Debate)

Yasmin Aziz, MD

International Stroke Conference 2021
March 17–19, 2021
Session: Mismatch Misalignments for Extended-window IV-thrombolysis for Non-Large Vessel Occlusion Strokes (Debate)
Moderator: Dr. Gotz Thomalla

Can thrombolytics be given safely and efficaciously beyond 4.5 hours? That was the debate topic for one of ISC’s first live debates to kick off Wednesday morning. 

Dr. Shlee Song: DWI-FLAIR Mismatch Rules!

The arguments began with Dr. Song, who focused on DWI-FLAIR mismatch. After a brief introduction with the MR WITNESS trial results, she then discussed how patients with DWI-FLAIR mismatch treated with alteplase had better outcomes at 90 days in the WAKE UP study. She also made the point that while efficient MRI scanning of acute stroke patients can be cumbersome, in addition to treating more patients, we can also avoid potential side effects of treating with conventional CT/CTA methods (i.e., contrast nephropathy and ICH in the event of unseen microhemorrhages only visible on MR).