Transcranial Doppler ultrasonography-directed intravenous glycoprotein IIb/IIIa receptor antagonist therapy to control transient cerebral microemboli before and after carotid endarterectomy

Cangrelor for emergent carotid stenting during stroke thrombectomy: a comparative analysis versus glycoprotein IIb/IIIa inhibitors or aspirin monotherapy

BACKGROUND

Periprocedural antiplatelet treatment is a key determinant for the risk-benefit balance of emergent carotid artery stenting (eCAS) during stroke endovascular treatment (EVT). We aimed to assess the safety and efficacy profile of cangrelor compared with glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors or aspirin monotherapy.

METHODS

Data were extracted from the Endovascular Treatment in Ischemic Stroke (ETIS) registry, a prospective nationwide observational registry of stroke EVT in France. Included patients were treated with eCAS for anterior circulation tandem lesions between January 2015 and June 2023 and received periprocedural treatment with cangrelor, GPIIb/IIIa inhibitors or aspirin monotherapy. The primary outcome was functional outcome at 90 days, assessed by the modified Rankin Scale (mRS). Secondary outcomes included intracranial recanalization, hemorrhagic transformation and carotid stent patency at day 1.

RESULTS

Of the 1687 patients treated, 384 met the inclusion criteria: 91 received cangrelor, 77 received GPIIb/IIIa inhibitors and 216 aspirin monotherapy. Cangrelor was associated with a negative shift in the distribution of mRS scores compared with GPIIb/IIIa inhibitors (aOR 0.48, 95% CI 0.25 to 0.94, P=0.033). Compared with aspirin, cangrelor improved carotid stent patency at day 1 (aOR 4.00, 95% CI 1.19 to 14.29, P=0.025) but showed no significant differences in clinical outcomes. There were no differences in outcomes between full dose and low dose cangrelor. GPIIb/IIIa inhibitors demonstrated higher odds of functional independence (aOR 2.56, 95% CI 1.08 to 6.25, P=0.033) compared with aspirin.

CONCLUSIONS

This registry-based study indicates a potential trend towards lower odds of favorable clinical outcomes with cangrelor treatment compared with GPIIb/IIIa inhibitors. However, these findings should be interpreted with caution due to potential selection bias and warrant further research for validation.

ASNM and ASN joint guidelines for transcranial Doppler ultrasonic monitoring: An update

Today, it seems prudent to reconsider how ultrasound technology can be used for providing intraoperative neurophysiologic monitoring that will result in better patient outcomes and decreased length and cost of hospitalization. An extensive and rapidly growing literature suggests that the essential hemodynamic information provided by transcranial Doppler (TCD) ultrasonography neuromonitoring (TCDNM) would provide effective monitoring modality for improving outcomes after different types of vascular, neurosurgical, orthopedic, cardiovascular, and cardiothoracic surgeries and some endovascular interventional or diagnostic procedures, like cardiac catheterization or cerebral angiography. Understanding, avoiding, and preventing peri- or postoperative complications, including neurological deficits following abovementioned surgeries, endovascular intervention, or diagnostic procedures, represents an area of great public and economic benefit for society, especially considering the aging population. The American Society of Neurophysiologic Monitoring and American Society of Neuroimaging Guidelines Committees formed a joint task force and developed updated guidelines to assist in the use of TCDNM in the surgical and intensive care settings. Specifically, these guidelines define (1) the objectives of TCD monitoring; (2) the responsibilities and behaviors of the neurosonographer during monitoring; (3) instrumentation and acquisition parameters; (4) safety considerations; (5) contemporary rationale for TCDNM; (6) TCDNM perspectives; and (7) major recommendations.

ABCD2 risk score does not predict the presence of cerebral microemboli in patients with hyper-acute symptomatic critical carotid artery stenosis

Introduction

ABCD² risk score and cerebral microemboli detected by transcranial Doppler (TCD) have been separately shown to the predict risk of recurrent acute stroke. We studied whether ABCD² risk score predicts cerebral microemboli in patients with hyper-acute symptomatic carotid artery stenosis.

Participants and methods

We studied 206 patients presenting within 2 weeks of transient ischaemic attack or minor stroke and found to have critical carotid artery stenosis (≥50%). 86 patients (age 70±1 (SEM: years), 58 men, 83 Caucasian) had evidence of microemboli; 72 (84%) of these underwent carotid endarterectomy (CEA). 120 patients (age 72±1 years, 91 men, 113 Caucasian) did not have microemboli detected; 102 (85%) of these underwent CEA. Data were analysed using X² and Mann–Whitney U tests and receiver operating characteristic (ROC) curves.

Results

140/206 (68%: 95% CI 61.63 to 74.37) patients with hyper-acute symptomatic critical carotid stenosis had an ABCD² risk score ≥4. There was no significant difference in the NICE red flag criterion for early assessment (ABCD² risk score ≥4) for patients with cerebral microemboli versus those without microemboli (59/86 vs 81/120 patients: OR 1.05 ABCD² risk score ≥4 (95% CI 0.58 to 1.90, p=0.867)). The ABCD² risk score was <4 in 27 of 86 (31%: 95% CI 21 to 41) embolising patients and in 39 of 120 (31%: 95% CI 23 to 39) without cerebral microemboli. After adjusting for pre-neurological event antiplatelet treatment (APT), area under the curve (AUC) of ROC for ABCD² risk score showed no prediction of cerebral microemboli (no pre-event APT, n=57: AUC 0.45 (95% CI 0.29 to 0.60, p=0.531); pre-event APT, n=147: AUC 0.51 (95% CI 0.42 to 0.60, p=0.804)).

Conclusions

The ABCD² score did not predict the presence of cerebral microemboli or carotid disease in over one-quarter of patients with symptomatic critical carotid artery stenosis. On the basis of NICE guidelines (refer early if ABCD² ≥4), assessment of high stroke risk based on ABCD² scoring may lead to inappropriate delay in urgent treatment in many patients.

A novel treatment for embolising carotid dissection

INTRODUCTION

A rare but significant cause for stroke is sub-intimal carotid dissection and this mechanism accounts for approximately 2.5% of all strokes.(1) Dissection of the carotid artery is often caused by trauma to the face or neck.(2) Under 45 years old, it is the second leading cause of stroke.(3) Neurological symptoms can be lacking or subtle, therefore the condition may be overlooked but the pathological processed is believed to be attributed to thromboembolism.(4) Microemboli in the middle cerebral artery, are known as a risk factor for ischaemic stroke following a transient ischaemic attack (TIA) and can be detected by transcranial Doppler examination (TCD).(5) The established treatment regime is antiplatelet therapy, anticoagulation or both along with supportive therapy.(6) Current evidence suggests managing microemboli in both crescendo TIA's and post carotid endarterectomy improves outcome.(7) We have found the use of Tirofiban, a potent intravenous antiplatelet agent currently licensed for use in acute coronary syndrome, effective in the treatment of microemboli in this manner.(7)

CASE PRESENTATION

We report a case of symptomatic carotid artery dissection post radical neck dissection, causing TCD detected microemboli and successfully treated with Tirofiban.

CONCLUSION

We believe further study into the use of Tirofiban in the treatment of microemboli after carotid dissection is indicated.

Microembolus detection by transcranial Doppler sonography: review of the literature

Transcranial Doppler can detect microembolic signals which are characterized by unidirectional high intensity increase, short duration, random occurrence, and a “whistling” sound. Microembolic signals have been detected in a number of clinical settings: carotid artery stenosis, aortic arch plaques, atrial fibrillation, myocardial infarction, prosthetic heart valves, patent foramen ovale, valvular stenosis, during invasive procedures (angiography, percutaneous transluminal angioplasty), surgery (carotid, cardiopulmonary bypass, orthopedic), and in certain systemic diseases. Microembolic signals are frequent in large artery disease, less commonly detected in cardioembolic stroke, and infrequent in lacunar stroke. This article provides an overview about the current state of technical and clinical aspects of microembolus detection.

Safety of Tirofiban in Acute Ischemic Stroke

Background and Purpose—

Tirofiban is a highly selective, fast-acting nonpeptide glycoprotein IIb/IIIa platelet receptor antagonist with a short half-life time. Glycoprotein IIb/IIIa antagonists are effective for the treatment of acute coronary syndromes proven in large clinical trials. Safety and efficacy in patients with ischemic stroke are uncertain. This was addressed in the Safety of Tirofiban in acute Ischemic Stroke (SaTIS) trial.

Methods—

Two hundred sixty patients with acute ischemic stroke were randomized in a placebo-controlled, prospective, open-label treatment, blinded outcome reading multicenter trial. Subjects with a National Institutes of Health Stroke Scale between 4 and 18 received intravenously either tirofiban or placebo within 3 to 22 hours after symptom onset for 48 hours. The primary end point was the rate of cerebral bleeding as measured in follow-up CT scans 2 to 7 days after inclusion. The secondary end point was clinical efficacy within 1 week (National Institutes of Health Stroke Scale, modified Rankin Scale) and after 5 months (Barthel Index, modified Rankin Scale).

Results—

The rate of cerebral hemorrhagic transformation (I/II) and parenchymal hemorrhage (I/II) did not differ between both groups (tirofiban 36 of 120; placebo 33 of 124: OR, 1.18; 95% CI, 0.66 to 2.06). Mortality after 5 months was significantly lower in patients treated with tirofiban (3 of 130 [2.3%] versus 11 of 126 [8.7%]; OR, 4.05; 95% CI, 1.1 to 14.9). No difference in neurological/functional outcome was found after 1 week and after 5 months.

Conclusions—

We conclude that tirofiban might be safe in acute moderate ischemic stroke even when administered within a large time window after symptom onset and might save lives in the late outcome.

Clinical Trial Registration—

URL: www.strokecenter.org/trials/ . Trial name: SaTIS. Enrollment began before July 1, 2005.

Perioperative transorbital Doppler flow imaging offers an alternative to transcranial Doppler monitoring in those patients without a temporal bone acoustic window

Transcranial Doppler has been used to identify microembolic signals before, during and after carotid endarterectomy, but 10% to 15% of patients are reported not to have suitable temporal bone window. The aim of this study was to assess the feasibility of transorbital Doppler monitoring of patients with absent temporal bone acoustic window. Between 2005 and 2008, those patients with absent temporal bone acoustic window were assessed for a transorbital acoustic window. During the study period, 318 carotid endarterectomy were performed. In the 29 (9.1%) with absent temporal bone acoustic window, 25 (86%) had satisfactory transorbital acoustic windows, consequently only four (1.2%) of patients could not be monitored postoperatively. One patient required postoperative transorbital acoustic windows directed glycoprotein IIb/IIIa receptor antagonist infusion due to excessive carotid microembolisation to prevent stroke. This is the first description of the use of transorbital flow imaging to determine postoperative cerebral blood flow, microembolic load and to direct the use of intravenous antiplatelet agents.

Carotid endarterectomy performed in the morning is associated with increased cerebral microembolization

OBJECTIVES

Platelet function exhibits circadian variation with highest levels of activity in the morning and plays a central role in arterial thrombotic events, including thrombotic stroke following carotid endarterectomy (CEA). Prior to the platelet-rich thrombus occluding the carotid artery, multiple embolic signals are detected in the middle cerebral artery using transcranial Doppler ultrasound. We hypothesized that patients undergoing CEA early in the day may be at an increased stroke risk and this would manifest as an increased postoperative embolic count.

METHODS

Data were collected prospectively on 235 patients undergoing primary CEA. Accurate start and finish times were recorded in addition to the number of postoperative emboli detected in the first three hours after CEA using transcranial Doppler (TCD) monitoring.

RESULTS

For operations finishing before midday, there was a 3.6-fold increase in the number of emboli detected relative to afternoon finishes (53.2 vs 14.8, P = .002) with similar results for starts before 10:30 AM (48.1 vs 14.7, P =.002). There was also a significant correlation between start time and emboli count (P = .02). Of the 55 patients with no postoperative emboli, only 19 had a morning start (relative risk 0.63, P = .011). Patients were 6.9 times more likely to require treatment with Dextran-40 to prevent progression onto a thrombotic stroke if their CEA finished before midday (P = .008).

CONCLUSION

There is a significantly increased rate of postoperative embolization for operations begun earlier in the day. Carotid endarterectomies performed in the afternoon may be at less risk of developing postoperative thrombotic stroke.