Glycoprotein IIb/IIIa Inhibitors in Prevention and Rescue Treatment of Thromboembolic Complications During Endovascular Embolization of Intracranial Aneurysms

Mimicking aneurysm in a patient with chronic occlusion of the left middle cerebral artery: A case report

BACKGROUND

With the popularization of various cerebrovascular imaging methods and increased attention to the field, more cerebrovascular diseases are being detected in asymptomatic patients. Different cerebrovascular diseases are typically isolated but occasionally occur simultaneously, causing difficulties in diagnosis and treatment. Morphological changes in the collateral circulation of blood vessels in chronic cerebral artery occlusion patients are slow and dynamic, intercepting morphological development at a specific moment. Excessive reliance on single imaging tests such as digital subtraction cerebral angiography (DSA) can lead to misdiagnosis.

CASE SUMMARY

We report a 52-year-old male who was admitted to our department for treatment of an unruptured aneurysm during a follow-up examination for brain trauma after 1 mo. Computed tomography (CT) scan was negative, but CT angiography (CTA) revealed a sac-like bulge at the bifurcation of the left middle cerebral artery. DSA revealed an unruptured aneurysm with unique scapular morphology. The stump of a middle cerebral artery occlusion was observed during exposure during aneurysm clipping surgery, and the diagnosis of chronic cerebral artery occlusion was confirmed intraoperatively. This case was confusing because of the peculiar morphology of the arterial stump and compensatory angiogenesis due to multiple cerebral artery stenoses observed on preoperative CTA and DSA. The surgery did not cause secondary damage to the patient, and medical treatment for risk factors was continued postoperatively.

CONCLUSION

Multiple cerebral arterial stenoses can occur in conjunction with aneurysms or arteriovenous malformations, and their unique morphology can lead to misdiagnosis.

Effects of Tirofiban in Patients with Acute Myocardial Infarction and Diabetes Mellitus undergoing Primary Percutaneous Coronary Intervention

OBJECTIVE

This study evaluated the efficacy and safety of early vs. late tirofiban administration in the treatment of patients with acute ST-elevation myocardial infarction (STEMI) and diabetes mellitus (DM) undergoing primary percutaneous coronary intervention (pPCI).

METHODS

120 patients with STEMI and DM treated with pPCI were randomly divided into an observation group (n=60) and a control group (n=60). The observation group and the control group were intravenously injected with a bolus of tirofiban preoperatively or intraoperatively, respectively; both groups were then given an intravenous infusion over 24 h at 0.15 μg/kg/min. Thrombolysis in myocardial infarction (TIMI) grade flow, myocardial perfusion index, and functional heart parameters, as well as major adverse cardiovascular events and bleeding, were compared between the two groups.

RESULTS

Functional heart parameters, including left ventricular ejection fraction and cardiac output, were significantly improved in the observation group 6 months after discharge. Thrombus aspiration, inflammatory factors, and cardiac troponin I (cTNI) were more significantly decreased in the observation group than in the control group. The sum-ST-segment elevation at 2 h after pPCI treatment in the observation group was better than that in the control group. There was no significant difference in the incidence of adverse reactions and bleeding between the two groups.

CONCLUSION

The administration of tirofiban before reperfusion therapy compared with after reperfusion therapy is more effective in reducing the hyperthrombotic load, thrombus aspiration, inflammatory factors, and cTNI and can effectively improve myocardial perfusion and heart function.

Flow-diverter stents in intracranial aneurysm treatment: impact on covered cerebral artery branches

OBJECTIVE

Flow diverter stents (FDSs) have attracted interest for intracranial aneurysm (IA) treatment; however, occlusion of side branches and related complications have been reported. This study aimed to investigate the effects of FDSs in IA management when different branches of intracranial arteries are covered.

MATERIALS AND METHODS

A cross-sectional study was conducted using PUBMED, Embase, Web of Science, and Cochrane databases to include randomized or nonrandomized comparative-designed studies from January 2000 to August 2022 which reported outcomes of occlusion/narrowing of branches after IA treatment using FDSs. The PRISMA guidelines were used for our report. A random-effects meta-analysis was conducted to pool the outcomes, which included incidence rates of occlusion/narrowing of FDS-covered branches, branch occlusion-related symptoms, obliteration of IAs, and ideal clinical outcomes (modified Rankin Scale score ≤2).

RESULTS

The authors identified 57 studies involving 3789 patients with IA managed by FDSs covering different branches. During the median imaging follow-up at 12 months, the IA obliteration rate was satisfactory (>70%) when covering the ophthalmic artery (OA), posterior communicating artery (PComA), anterior choroidal artery (AChoA) or anterior cerebral artery (ACA), but not the middle cerebral artery-M2 segment (MCA-M2; 69.5%; 95% CI: 60.8-77.5%) and posterior inferior cerebellar artery (PICA; 59.1%, 13/22). The overall ideal clinical outcome was observed in 97.4% of patients (95% CI: 95.5-98.9%). Higher rates of occlusion/narrowing of branches were identified when FDSs covered the ACA (66.6%; 95% CI: 45.1-85.3%), PComA (44.3%; 95% CI: 34.2-54.6%), or MCA-M2 (39.2%; 95% CI: 24.5-54.7%); the risks were lower when covering the OA (11.8%; 95% CI: 8.8-15.1%), PICA (6.8%; 95% CI: 1.5-14.5%), and AchoA (0.5%; 95% CI: 0.0-2.9%). The risk of branch occlusion-related complications was low (incidence rate <5%) for each of the six evaluated branches.

CONCLUSIONS

Acceptable outcomes were identified following treatment of IAs when FDSs were placed across each of the six studied cerebral arteries. Treatment decisions regarding FDS placement across branch arteries should be made with the risk of complications from branch occlusion in mind.

Efficacy and safety of low dose intravenous cangrelor in a consecutive cohort of patients undergoing neuroendovascular procedures

BACKGROUND

Cangrelor is an intravenous P2Y12 inhibitor with rapid onset and fast offset of antiplatelet action. Dose adjusted cangrelor based on platelet function testing is suggested to be advantageous for use during neuroendovascular procedures. In this study, we aimed to assess the efficacy and safety of this strategy.

METHODS

This retrospective study included consecutive patients who received low dose intravenous cangrelor (5 µg/kg; infusion 1 µg/kg/min) for ruptured (RIA) and unruptured (UIA) intracranial aneurysms, and acute ischemic stroke (AIS). Indications were acute stenting or intraluminal thrombus. Outcomes were assessed at 24 hours by brain CT and CT angiography. The primary efficacy outcome was the rate of stent occlusion or persistent intraluminal thrombus. The primary safety outcome was the rate of major hemorrhages.

RESULTS

101 patients (56 men; median age (IQR) 59 (51-70) years) received low dose cangrelor for acute stenting (79/101 (78%)) and intraprocedural thrombus (22/101 (22%)). Overall, 5 (4.9%) patients experienced stent occlusion within 24 hours (RIA 3/28; AIS 2/52). There were no cases of failure among UIA patients. Stent mis-opening (fish mouthing or stenosis >50%) was significantly associated with stent occlusion (P<0.001). The overall rate of major hemorrhage was 2% (2/101), which occurred in AIS patients. Platelet reactivity unit (PRU) values were lower in those presenting with major hemorrhage (PRU 4 (SD 1.4) vs PRU 60 (SD 63); P=0.043). Mortality rate after cangrelor related hemorrhage was 1%.

CONCLUSIONS

Low dose cangrelor appears to be effective in preventing stent thrombosis and arterial patency with a low hemorrhagic risk.

Efficacy and safety of intracoronary versus intravenous tirofiban in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: A meta-analysis of randomized controlled trials

Background

Effective antiplatelet therapy is critical for patients with ST-segment elevation myocardial infarction (STEMI) and receiving primary percutaneous coronary interventions (PPCI). Intracoronary (IC) and intravenous (IV) administration of tirofiban are commonly used during the procedure of PPCI. However, which is the better administration route of tirofiban have not been fully evaluated.

Methods

A comprehensive literature search of RCTs that comparing IC with IV tirofiban in STEMI patients undergoing PPCI was conducted, which were published as of May 7, 2022, in PubMed, Embase, Cochrane Library, Web of Science, Scopus and ClinicalTrials.gov. The primary efficacy endpoint was 30-day major adverse cardiovascular events (MACE) and the primary safety endpoint was in-hospital bleeding events.

Results

This meta-analysis included 9 trials involving 1177 patients. IC tirofiban significantly reduced the incidence of 30-day MACE (RR 0.65, 95% CI: 0.44 to 0.95, P = 0.028) and improved the rate of the thrombolysis in myocardial infarction (TIMI) grade 3 flow in high-dose (25 μg/kg) group (RR = 1.13, 95% CI: 0.99-1.30, P = 0.001), in-hospital (WMD 2.03, 95% CI: 1.03 to 3.02, P < 0.001), and 6-month left ventricular injection fraction (LVEF) (WMD 6.01, 95% CI: 5.02 to 6.99, P < 0.001) compared with IV. There was no significant difference in the incidences of in-hospital bleeding events (RR 0.96, 95% CI: 0.67 to 1.38, P = 0.82) and thrombocytopenia (RR 0.63, 95% CI: 0.26 to 1.57, P = 0.32) between the two groups.

Conclusions

IC tirofiban significantly improved the incidence of TIMI 3 in the high-dose group, in-hospital and 6-month LVEF, and reduced the 30-day MACE incidence without increasing the risk of bleeding compared with IV.

Antithrombotic therapies for neurointerventional surgery: a 2021 French comprehensive national survey

BACKGROUND

Neurointerventionists lack guidelines for the use of antithrombotic therapies in their clinical practice; consequently, there is likely to be significant heterogeneity in antithrombotic use between centers. Through a nationwide survey, we aimed to obtain an exhaustive cross-sectional overview of antithrombotic use in neurointerventional procedures in France.

METHODS

In April 2021, French neurointerventional surgery centers were invited to participate in a nationwide 51-question survey disseminated through an active trainee-led research collaborative network (the JENI-RC).

RESULTS

All 40 centers answered the survey. Fifty-one percent of centers reported using ticagrelor and 43% used clopidogrel as premedication before intracranial stenting. For flow diversion treatment, dual antiplatelet therapy was maintained for 3 or 6 months in 39% and 53% of centers, respectively, and aspirin was prescribed for 12 months or more than 12 months in 63% and 26% of centers, respectively. For unruptured aneurysms, the most common heparin bolus dose was 50 IU/kg (59%), and only 35% of centers monitored heparin activity for dose adjustment. Tirofiban was used in 64% of centers to treat thromboembolic complications. Fifteen percent of these comprehensive stroke centers reported using tenecteplase to treat acute ischemic strokes. Cangrelor appeared as an emergent drug in specific indications.

CONCLUSION

This nationwide survey highlights the important heterogeneity in clinical practices across centers. There is a pressing need for trials and guidelines to further evaluate and harmonize antithrombotic regimens in the neurointerventional field.

An Updated Review on Glycoprotein IIb/IIIa Inhibitors as Antiplatelet Agents: Basic and Clinical Perspectives

The glycoprotein (GP) IIb/IIIa receptor is found integrin present in platelet aggregations. GP IIb/IIIa antagonists interfere with platelet cross-linking and platelet-derived thrombus formation through the competition with fibrinogen and von Willebrand factor. Currently, three parenteral GP IIb/IIIa competitors (tirofiban, eptifibatide, and abciximab) are approved for clinical use in patients affected by percutaneous coronary interventions (PCI) in the location of acute coronary syndrome (ACS). GP IIb/IIIa antagonists have their mechanism of action in platelet aggregation prevention, distal thromboembolism, and thrombus formation, whereas the initial platelet binding to damage vascular areas is preserved. This work is aimed to provide a comprehensive review of the significance of GP IIb/IIIa inhibitors as a sort of antiplatelet agent. Their mechanism of action is based on factors that affect their efficacy. On the other hand, drugs that inhibit GP IIb/IIIa already approved by the FDA were reviewed in detail. Results from major clinical trials and regulatory practices and guidelines to deal with GP IIb/IIIa inhibitors were deeply investigated. The cardiovascular pathology and neuro-interventional surgical application of GP IIb/IIIa inhibitors as a class of antiplatelet agents were developed in detail. The therapeutic risk/benefit balance of currently available GP IIb/IIa receptor antagonists is not yet well elucidated in patients with ACS who are not clinically evaluated regularly for early cardiovascular revascularization. On the other hand, in patients who have benefited from PCI, the antiplatelet therapy intensification by the addition of a GP IIb/IIIa receptor antagonist (intravenously) may be an appropriate therapeutic strategy in reducing the occurrence of risks of thrombotic complications related to the intervention. Development of GP IIb/IIIa inhibitors with oral administration has the potential to include short-term antiplatelet benefits compared with intravenous GP IIb/IIIa inhibitors for long-term secondary preventive therapy in cardiovascular disease. But studies showed that long-term oral administration of GP IIb/IIIa receptor inhibitors has been ineffective in preventing ischemic events. Paradoxically, they have been linked to a high risk of side effects by producing prothrombotic and pro-inflammatory events.

The efficacy and safety of intravenous tirofiban in the treatment of acute ischemic stroke patients with early neurological deterioration

WHAT IS KNOWN AND OBJECTIVE

Many patients with acute ischemic stroke (AIS) develop early neurological deterioration (END), leading to disabilities or death. Thus, this study aimed to investigate the efficacy and safety of intravenous tirofiban in treating patients with AIS and END who missed the thrombolysis time window.

METHODS

A total of 123 AIS-END patients participated in the study between January 2021 and December 2021. Patients were randomized into the tirofiban group (n = 63) and the control group (n = 60) based on whether a tirofiban injection was administered. The National Institute of Health Stroke Scale (NIHSS) was used to assess neurological function at the 48th hour and on the 7th day after intervention, and the modified Rankin Scale (mRS) was used to assess neurological recovery 90 days after AIS. Adverse reactions during the intervention were recorded for safety analysis.

RESULTS AND DISCUSSION

The 7th day NIHSS and 90th day post-AIS mRS scores of the tirofiban group were significantly lower than those of the control group (p < 0.05), while the 90th day good prognosis (mRS ≤ 2) rate of the tirofiban group was significantly higher (84.13% vs. 65.00%, p < 0.05). Logistic regression demonstrated a protective effect of tirofiban for good prognosis in AIS patients with END (OR = 4.675, 95% CI [1.012-21.605], p < 0.05). No cases of intracranial haemorrhage transformation or death were observed during the treatment in either group.

WHAT IS NEW AND CONCLUSION

Tirofiban injection exhibited a high safety profile and significantly improved the prognosis of AIS-END patients who missed the intravenous thrombolysis time window.

The Prophylactic Use of Glycoprotein 2b/3a Inhibitors in the Endovascular Treatment of Intracranial Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

There has been a growing interest in the use of Glycoprotein 2b/3a (GP2B3A) inhibitors in neuroendovascular procedures. However, clinical evidence for their prophylactic use is still sparse. In this review, we aimed to assess the safety and efficacy of prophylactic GP2B3A inhibitor use and to compare the performance of GP2B3A inhibitors with oral dual antiplatelet (DAP) treatment in intracranial aneurysm patients treated with stent-assisted coil embolization or flow diversion.

METHODS

A systematic literature search was conducted in Ovid MEDLINE, Ovid Embase, Scopus, Web of Science, and Cochrane Central Register of Clinical Trials databases. Data collected included hemorrhagic and thromboembolic complication rates, mortality, good functional outcome, and rupture status. A random-effects model was fit for each outcome measure.

RESULTS

Thirteen studies comprising 1429 patients were included. The overall hemorrhagic complication rate of the GP2B3A cohort was 3.98% (95% confidence interval [CI] = 1.58-7.42). The subgroup analysis comparing ruptured versus unruptured aneurysms in which GP2B3A antagonists were used did not show a significant difference in hemorrhagic complication rates (P-value = 0.504). Compared with the DAP group, the GP2B3A inhibitor cohort had significantly lower hemorrhagic complication rates (odds ratio = 0.33; 95% CI = 0.13-0.85; P-value = 0.022). The thromboembolic complication rates were 6.63% (95% CI = 3.44-10.75) for the GP2B3A inhibitor group and 10.4% (95% CI = 7-13.8) for the DAP group. However, the difference was not statistically significant (odds ratio = 0.52; 95% CI = 0.22-1.24; P-value = 0.142).

CONCLUSIONS

Our results support that GP2B3A inhibitors are safe and effective in preventing ischemic complications associated with the endoluminal devices. Additionally, our findings indicate that GP2B3A inhibitors can be utilized as prophylactic agents regardless of the rupture status.

Clinical safety and possible efficacy of tirofiban in combination with intravenous thrombolysis by recombinant tissue plasminogen activator for early treatment of capsular warning syndrome (CWS)

The purpose of this study was to assess the efficacy and safety of the combination of tirofiban with intravenous thrombolysis (IVT) in treating patients with capsular warning syndrome (CWS) who failed to respond to the treatment of intravenous thrombolysis alone. Tirofiban was approved for the treatment of CWS patients with fluctuating symptoms or no substantial improvement after intravenous thrombolysis within 24 h in our hospital from October 2019 to June 2021. Patients were evaluated with the National Institutes of Health Stroke Scale (NIHSS) at admission, at 72 h post-thrombolysis, at 1-week, and at 3-months with the modified Rankin Scales (MRS) score. A total of 12 patients received tirofiban and eight patients received control treatment with a history of CWS in our cohort. Among the patients, 13 patients smoked more than one pack of cigarettes a day, 17 had hypertension, 17 had hypercholesterolemia, 7 had diabetes, 1 had the history of cerebral infarction, 2 had atrial fibrillation, 7 had mild big vascular stenosis, 13 had lesions of the perforating branch by imaging, and 19 had acute capsular infarction. In both the tirofiban and control groups, NIHSS scores were significantly reduced after intravenous thrombolysis or 1-week after onset compared with before intravenous thrombolysis (P &lt; 0.001). Before and after intravenous thrombolysis, there were no differences between the tirofiban group and control group (P = 0.970, P = 0.384, respectively). The tirofiban group, however, showed remarkably lower scores in both 1-week NIHSS and 3-month MRS than the control (P = 0.012, P = 0.003, respectively). Our study revealed that tirofiban did not increase the risk of hemorrhage and had favorable clinical efficacy as a remedial treatment for CWS patients with poor prognosis for intravenous thrombolysis, therefore indicating great potential for broader use.

Continuous Intraarterial Nimodipine Infusion for the Treatment of Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage: A Retrospective, Single-Center Cohort Trial

Background

Delayed cerebral ischemia (DCI) occurs after aneurysmal subarachnoid hemorrhage (aSAH). Continuous intraarterial nimodipine infusion (CIAN) is a promising approach in patients with intracranial large vessel vasospasm (LVV). The objective of this retrospective single-center cohort study was to evaluate the outcome in aSAH-patients treated with CIAN.

Methods

CIAN was initiated and ended based on the clinical evaluation and transcranial Doppler (TCD), CT-angiography, CT-perfusion (PCT), and digital subtraction angiography (DSA). Nimodipine (0.5–2.0 mg/h) was administered continuously through microcatheters placed in the extracranial internal carotid and/or vertebral artery. Primary outcome measures were Glasgow Outcome Scale (GOS) at discharge and within 1 year after aSAH, and the occurrence of minor and major (<⅓ and >⅓ of LVV-affected territory) DCI-related infarctions in subsequent CT/MRI-scans. Secondary outcome measures were CIAN-associated complications.

Results

A total of 17 patients underwent CIAN. Median onset of CIAN was 9 (3–13) days after aSAH, median duration was 5 (1–13) days. A favorable outcome (GOS 4–5) was achieved in 9 patients (53%) at discharge and in 13 patients within 1 year (76%). One patient died of posthemorrhagic cerebral edema. Minor cerebral infarctions occurred in five and major infarctions in three patients. One patient developed cerebral edema possibly due to CIAN. Normalization of PCT-parameters within 2 days was observed in 9/17 patients. Six patients showed clinical response and thus did not require PCT imaging.

Conclusion

The favorable outcome in 76% of patients after 1 year is in line with previous studies. CIAN thus may be used to treat patients with severe therapy-refractory DCI.

Recent advance in treatment of atherosclerosis: Key targets and plaque-positioned delivery strategies

Atherosclerosis, a chronic inflammatory disease of vascular wall, is a progressive pathophysiological process with lipids oxidation/depositing initiation and innate/adaptive immune responses. The coordination of multi systems covering oxidative stress, dysfunctional endothelium, diseased lipid uptake, cell apoptosis, thrombotic and pro-inflammatory responding as well as switched SMCs contributes to plaque growth. In this circumstance, inevitably, targeting these processes is considered to be effective for treating atherosclerosis. Arriving, retention and working of payload candidates mediated by targets in lesion direct ultimate therapeutic outcomes. Accumulating a series of scientific studies and clinical practice in the past decades, lesion homing delivery strategies including stent/balloon/nanoparticle-based transportation worked as the potent promotor to ensure a therapeutic effect. The objective of this review is to achieve a very brief summary about the effective therapeutic methods cooperating specifical targets and positioning-delivery strategies in atherosclerosis for better outcomes.

Safety and Efficacy of Cangrelor Among Three Antiplatelet Regimens During Stent-Assisted Endovascular Treatment of Unruptured Intracranial Aneurysm: A Single-Center Retrospective Study

Introduction

Thromboembolic events represent the most frequent complications of endovascular treatment of unruptured intracranial aneurysm using stent-assisted coilling or flow diverter stents. Dual antiplatelet therapy has become the standard to prevent these but remains unstandardized. We present here a single center experience of 3 standardized antiplatelet regimens during brain aneurysm treatment, while emphasizing the use of the Cangrelor.

Method

We retrospectively reviewed data from patients treated using stent-assisted coilling or flow diverter stents from 2016 to 2021. We collected and compared safety and efficacy data within 6 months of three groups of patients corresponding to three antiplatelet standardized regimens: group T with Ticagrelor, with preprocedural preparation; group E with Eptifibatide, injected during procedure; group C with Cangrelor, injected during procedure.

Results

Data of 112 patients were analyzed and 76 belonged to group T, 21 to group E, and 15 to group C. Eleven events over the 14 recorded were adjudicated to be related to antiplatelets, their repartition did not differ between the 3 groups (p = 0.43). All symptomatic events (N = 8) were not distributed significantly differently between the 3 groups (p = 0.11) and asymptomatic events were also balanced (p = 1.00). Of these, 6 subjects had a change in the mRS score at 3–6 months. Thrombo-embolic events represented the most encountered events in the sample: 2 acute ischemic strokes were recorded in group E and 1 in group T; 1 transient ischemic stroke was noted in group E; 4 silent infarcts were found on control MRI (2 belonged to group T, 1 to group E and 1 to group C). Among 3 intracranial bleeding events, 1 was symptomatic in group C, 2 were asymptomatic in group T. On the control evaluation performed at 6 months, there was no significant difference on aneurysmal occlusion (p = 0.67).

Conclusion

This single-center retrospective study compared 3 antiplatelet regimens, finding no significant difference in the safety and efficacy in the context of endovascular treatments of unruptured aneurysm using stent or flow diverters. This study adds data for the Cangrelor use and suggests its usefulness in the field of neuro-endovascular intervention. Randomized controlled studies are warranted to confirm these results.

Glycoprotein IIb/IIIa inhibitors for the neurointerventionalist

Antiplatelet therapies are commonly used in neurointerventional procedures. However, specific guidelines for their use in these settings is lacking and it can often be difficult to balance the potential risks and benefits of these medications. Considering the continued growth and adoption of neurointerventional procedures, it is crucial to understand the properties of these agents in order to use them safely. Large-scale clinical trials are still needed to clarify many of these aspects for this emerging field. However, the existing literature already provides insight into which antiplatelet drugs are of benefit to the neurointerventionalist as well as their associated risks of ischemic and hemorrhagic complications. Hence, this review focuses on the applications of GPIIb/IIIA inhibitors to neurointerventional procedures.

Investigation of the effect of anticoagulant usage in the flow diverter stent treatment of the patient-specific cerebral aneurysm using the Lagrangian coherent structures

Anticoagulants are prescribed to the flow diverter treated patients to diminish the risk of embolism in the arteries. In the present study, digital subtraction angiography images of a 49-year-old female patient with a left paraophthalmic aneurysm were used to build a numerical model to investigate the effect of an anticoagulant on hemodynamics at the aneurysm site. The Carreau-Yasuda viscosity model was utilized to define blood viscosity, and the coefficients of the viscosity model were updated based on the usage of warfarin. The five-cardiac cycle-long numerical simulations were performed, and Lagrangian coherent structures, hyperbolic time, and fluid particle analyses were also employed in the numerical models. These analyses allowed us to evaluate the formation of stagnated regions, recirculation zones, and the number of jailed particles inside the aneurysm sac following a flow diverter placement. It is realized that anticoagulant use caused blood to be less viscous, yielding a substantial amount of incoming blood flow to enter the aneurysm sac. Only 12% of the nearly 25,000 fluid particles seeded from the artery inlet have stayed inside the sac. Furthermore, the deviation between warfarin added blood and normal blood flow becomes more extensive, with every heartbeat undermining the effectiveness of patient-specific CFD models when the use of anticoagulants is overlooked in the viscosity models.

Safety and efficacy of intravenous tirofiban for stent-assisted coiling in acutely ruptured intracranial aneurysms: A single center experience

BACKGROUND

There have been few reports on the use of tirofiban in ruptured intracranial aneurysms and the results were conflicting. However, the safety and efficacy of optimal dosage and the reasonable treatment course of tirofiban have not been determined.

OBJECTIVE

To determine the safety and efficacy of a new protocol for its prophylactic tirofiban application during the endovascular treatment of ruptured intracranial aneurysms with no oral antiplatelet medications.

METHODS

This retrospective study was based on 105 patients with ruptured aneurysms who underwent stent-assisted coiling at our institution between August 2017 and July 2020. Intravenous tirofiban was administered to patients after stent deployment. Tirofiban was administered as an intravenous bolus (5 µg/kg) over a 3 min period immediately after stent deployment, followed by a 0.06-0.08 µg/kg/min maintenance infusion for 12-24 h. Dual oral antiplatelet therapy was overlapped with half the tirofiban dose 2 h before the cessation of the tirofiban infusion. Cases of intracranial hemorrhage or thromboembolism were recorded.

RESULTS

This study included a total of 105 patients with ruptured intracranial aneurysms, who underwent stent-assisted coiling. In terms of clinical severity, a presenting Hunt-Hess clinical-grade I was observed in 47 (44.8%) cases, grade II in 19 (18.1%) cases, grade III in 30 (28.6%) cases, grade IV in 6 (5.6%) cases, and grade V in 3 (2.9%) cases. None of the patients showed a newly developed tirofiban-related intracerebral hemorrhage, intraventricular hemorrhage, subarachnoid hemorrhage, or ventriculostomy-related hemorrhage. There were 3 (2.8%) patients who had thromboembolic complications.

CONCLUSIONS

We have determined a new protocol for prophylactic intraoperative tirofiban during the endovascular treatment of ruptured intracranial aneurysms with no oral antiplatelet medications. In our study, tirofiban showed a low risk of hemorrhagic or thromboembolic complications. Tirofiban appears to be a safe and alternative during the stent-assisted coiling of ruptured intracranial aneurysms.

Characterization of antiplatelet response to low-dose cangrelor utilizing platelet function testing in neuroendovascular patients

STUDY OBJECTIVES

The optimal antiplatelet therapy for emergent neuroendovascular stenting is uncertain. Cangrelor is an intravenous P2Y12 inhibitor that is an attractive option due its favorable pharmacokinetic profile and ease of measurability but optimal dosing remains unclear. The primary objective of this study is to characterize the dose response of low dose cangrelor (<2 mcg/kg/min) with the utilization of platelet function testing (PFT).

DESIGN

A retrospective review of all patients treated with cangrelor for either procedural stenting or bridging was conducted between January 1st, 2019 and October 31st, 2020. Seventy-two patients met inclusion criteria. An in-depth analysis of dose response to low dose cangrelor based on PFT was performed.

PATIENTS

Neuroendovascular patients treated with cangrelor.

SETTING

Albany Medical Center Hospital.

INTERVENTION AND MAIN RESULTS

Patients who underwent procedural stenting were given a bolus of 5 mcg/kg and an initial infusion rate of either 0.75 mcg/kg/min or 1 mcg/kg/min. Patients who were bridged with cangrelor were administered an initial infusion rate of 0.75 mcg/kg/min or 1 mcg/kg/min. Twelve patient's doses were titrated to achieve a platelet reactivity unit (PRU) between 50-150; three patient's doses were titrated multiple times. Based on initial PFT results, utilizing the 1 mcg/kg/min maintenance dose resulted in more patients being in the acceptable (10-180) and desired (50-150) PRU range than the 0.75 mcg/kg/min dose (47% vs 56% and 70% vs 80%, respectively). Final recorded PRU results showed that 64% of patients had PRUs in the optimal range (50-150) and 88% of patients had PRUs in the desire range (10-180).

CONCLUSIONS

Utilizing low doses of cangrelor with platelet function testing is an option during emergent neuroendovascular stenting and bridging. Cangrelor demonstrates significant variability in response at low doses and exhibits a dose response relationship when PFT is utilized.

Assessing the Efficacy and Safety of Tirofiban in Combination With Dual-antiplatelet Therapy in Progressive Ischemic Stroke Patients

ABSTRACT

This study assessed the efficacy and safety of tirofiban in combination with dual-antiplatelet therapy (DAPT) in progressive ischemic stroke. One hundred and four patients equally divided into a tirofiban group or DAPT group were enrolled from June 2018 to December 2019. Efficacy outcomes included National Institutes of Health Stroke Scale score for 14 days, and modified Rankin scale (mRs) scores as excellent (mRs 0-1) or favorable (mRs 0-2) measured 90 days after stroke. At 14 days, the tirofiban group had a lower National Institutes of Health Stroke Scale score compared with the DAPT group (F = 14.959, P = 0.000). The mRS scores of the 2 groups at 90 days after treatment were significantly different from those before treatment. At 90 days, excellent favorable functional outcome (mRS ≤ 2) was achieved in 33 of 52 (63.43%) patients in the tirofiban group compared with 25 of 52 (48.08%) patients in the DAPT group. The incidence of bleeding was 5.77% in the tirofiban group, compared with 0% in DAPT group. Intravenous (IV) tirofiban alone or combined with DAPT was shown to be safe and effectively improved clinical outcome in progressive ischemic stroke patients. IV tirofiban was shown to be superior to the DAPT regimen.

Management of tandem occlusions in patients who receive rtPA

BACKGROUND

Tandem occlusions exist in 17-32% of large vessel occlusion (LVO) strokes. A significant concern is bleeding when carotid stenting is performed in tandem with thrombectomy due the administration of antiplatelet agents such as glycoprotein IIb/IIIa inhibitors (GP2b3aI) after receiving rtPA, but data are limited in this setting.

METHODS

A mutlicenter, retrospective chart review was conducted at two comprehensive stroke centers to assess the safety and efficacy of using GP2b3aI to facilitate carotid stent placement simultaneously with endovascular thrombectomy in patients who have received rtPA.

RESULTS

Overall, 32 patients were included in this study, with average age of 66.3 ± 10.4 years and predominantly male (87.5%). The cause of stroke was mostly large artery atherosclerosis (59.4%) and the thrombectomy target vessels were typically first- or second segment middle cerebral artery (37.5% and 31.3%). Time from symptom onset to rtPA bolus was 1.8 h [interquartile range (IQR) 1.5-2.7], rtPA bolus to first pass was 2 h [IQR 1.5-3.1], rtPA bolus to GP2b3aI bolus was 2 h [IQR 1.6-3.5], and rtPA bolus to aspirin and clopidogrel administration was 4.3 h [IQR 2.6-8.9] and 6.6 h [IQR 4.5-11.6] respectively. No patients had acute in-stent thrombosis or post-op bleeding from the access site. Two patients (6.3%) had significant hemorrhagic conversion.

CONCLUSION

The use of GP2b3aI in the setting of tandem occlusions that required emergent stent placement post-rtPA appears safe and effective. Given the small sample size, these findings should be interpreted cautiously, and need to be confirmed in a larger patient population.

Acute Stenting and Concomitant Tirofiban Administration for the Endovascular Treatment of Acute Ischemic Stroke Related to Intracranial Artery Dissections: A Single Center Experience and Systematic Review of the Literature

BACKGROUND

Intracranial artery dissection is an uncommon cause of acute ischemic stroke. Although acute stenting of the dissected arterial segment is a therapeutic option, the associated antiplatelet regimen remains a matter of debate.

OBJECTIVES

To evaluate the efficacy and safety of acute intracranial stenting together with concomitant intravenous administration of tirofiban and to perform a systematic review of the literature.

MATERIALS AND METHODS

A single-center, retrospective study of the clinical and radiological records of all patients treated at our center by intracranial stenting in the setting of acute ischemic stroke between January 2010 and December 2020. A systematic review of the literature was conducted according to the PRISMA-P guidelines for relevant publications from January 1976 to December 2020 on intracranial artery dissection treated by stent.

RESULTS

Seven patients with intracranial artery dissections underwent acute stenting with concomitant tirofiban during the study period. Mid-term follow-up showed parent artery patency in 6/7 cases (85.7%). The modified Rankin Score was ≤ 0-2 at 3 months in 5/7 cases (71.4%). The literature review identified 22 patients with intracranial artery dissection treated with acute stenting in association with different antithrombotic therapies. Complete revascularization was obtained in 86.3% of cases with a modified Rankin Score of ≤ 0-2 in 68% of patients at 3-month follow-up.

CONCLUSIONS

Acute intracranial stenting together with intravenous tirofiban administration could be a therapeutic option in patients with intracranial artery dissection and a small ischemic core.

Intravenous abciximab as a rescue therapy for immediate reocclusion after successful mechanical thrombectomy in acute ischemic stroke patients

Background - Immediate reocclusion after mechanical thrombectomy (MT) for acute ischemic stroke (AIS) is a rare but devastating condition associated with poor functional outcome.Objective - The aim of this study was to gain insights into the mechanisms underlying immediate reocclusion, and to evaluate the efficacy and safety of the glycoprotein IIb/IIIa antagonist abciximab, for its treatment.Methods - Clinical data were collected from April 2015 to April 2019 in a monocentric prospective registry of AIS patients treated by MT. All patients with immediate reocclusion were retrospectively selected and subdivided into 2 groups according to abciximab treatment status. In vitro, the separate and combined effects of abciximab and alteplase on clot formation in whole blood under flow conditions were further investigated in microfluidic chambers.Results - From 929 MT-treated patients, 21 had post-MT immediate reocclusion. Abciximab treatment in reocclusion patients (n = 10) led to higher rate of final recanalization (p < .001) while it did not increase bleeding complications. Flow chamber experiments revealed that, in contrast to alteplase, abciximab efficiently limits thrombus accretion from flowing blood by blocking platelet aggregation.Conclusions - Our results underscore a key role for platelet aggregation and the potential of Glycoprotein IIb/IIIa antagonists as a rescue therapy in post-MT immediate reocclusion.

Successful rescue treatment of right posterior inferior cerebellar artery (PICA) vascular stasis with tirofiban following endovascular coil implantation

This report describes a patient who developed intraprocedural vascular stasis immediately following elective endovascular coil emboliation. Urgent antiplatelet treatment with the GpIIb/IIIa agent tirofiban was used. It was infused intra-arterially during the procedure, followed by a fixed rate intravenous continuous infusion, and successfully restored normal circulation. There were no reports of further bleeding or haemodynamic compromise during the hospital stay. The patient’s condition returned to baseline and he was discharged the following day with no neurological deficits.

Adjunctive treatment with low dose intra-arterial eptifibatide and intravenous aspirin during carotid stenting: A case series

PURPOSE

According to most guidelines, medical protocol for carotid stenting includes the administration of oral Aspirin and Clopidogrel at least four days before the procedure, with intraprocedural intravenous (IV) heparin. Some publications have also reported the safety of adding glycoprotein 2b/3a inhibitors to the protocol. In this retrospective study, we evaluate the safety of a new medication protocol that includes IV aspirin and intra-arterial Eptifibatide (glycoprotein 2b/3a inhibitor) during carotid stenting. All patients who underwent carotid stenting at Soroka University Medical Center between January 2015 and May 2020 were included (emergent cases were excluded). We divided patients into two groups-patients treated under the standard protocol, and patients treated under the new protocol. In the latter, patients received both the standard protocol regimen, as well as 150 mg IV aspirin immediately before stenting, and a slow intra-arterial injection of 2-3 mg Eptifibatide (glycoprotein 2b/3a antagonist) immediately after stenting. Forty-four patients were treated according to the standard protocol (group 1), and 41 patients were treated according to the new protocol (group 2). In group 1, six patients had complications, while in group 2, no complications of any kind were noted (p = 0.027). The safety and possible efficacy of this novel protocol was preliminarily demonstrated in the present study. Future studies are needed to prove the safety and efficacy of a specific drug regimen that will further reduce the complication rates of carotid stenting.

Prophylactic administration of tirofiban for preventing thromboembolic events in flow diversion treatment of intracranial aneurysms

BACKGROUND

Flow diverter (FD) is widely used in the treatment of intracranial aneurysms. However, thromboembolic events (TEs) continue to be the major complications during the periprocedural phase. To evaluate the safety and efficacy of the prophylactic use of tirofiban, combined with the conventional dual antiplatelet therapy (DAT), as a new antiplatelet protocol in patients with intracranial aneurysms treated with FDs.

METHODS

At least 3-5 days before the procedure, daily DAT were administrated to the patients. Tirofiban was administered as an intravenous bolus (5 µg/kg) over a 3 min period during or immediately after FD deployment, followed by a 0.05 µg/kg/min maintenance infusion for 24-48 hours. Periprocedural TEs and hemorrhagic events (HEs) were recorded.

RESULTS

A total of 331 patients were included, including 229 (69.2%) who received tirofiban administration (tirofiban group) and 102 (30.8%) who received only DAT (non-tirofiban group). Periprocedural TEs occurred in 12 (3.6%) patients, including eight (7.8%) in the non-tirofiban group and four (1.7%) in the tirofiban group. In multivariate analysis, patients receiving tirofiban administration had significantly lower TEs as compared with those who received only DAT (P=0.004). Balloon angioplasty and longer procedure time (>137 min) were also risk factors for TEs. Also, no increase was observed in the rate of HEs related to tirofiban administration.

CONCLUSIONS

The current study suggested that prophylactic administration of tirofiban combined with conventional oral DAT seems safe and efficient for preventing TEs during FD treatment of unruptured intracranial aneurysms. Balloon angioplasty and prolonged procedure are associated with a high risk of TEs.

The use of cangrelor in neurovascular interventions: a multicenter experience

PURPOSE

Thromboembolic events represent the most common procedure-related complication associated with neurointerventions. Cangrelor is a potent, intravenous (IV), P2Y12-receptor antagonist with a rapid onset and offset presented as an alternative antiplatelet agent. We aim to evaluate the safety and effectiveness of IV cangrelor in neurovascular intervention.

METHODS

This is a retrospective analysis of data from four cerebrovascular interventional centers. We identified patients who underwent acute neurovascular intervention and received cangrelor as part of their optimum care. Patients were divided into 2 groups: ischemic and aneurysm. Periprocedural thromboembolic events, hemorrhagic complications, and outcomes were analyzed.

RESULTS

Sixty-six patients were included, 42 allocated into the ischemic group (IG), and 24 into aneurysm group (AG). The IG periprocedural symptomatic complication rate was 9.5%, represented by 3 postoperative intracranial hemorrhages and 1 retroperitoneal hematoma. At discharge, 47.6% had a favorable outcome and the mortality rate was 2.4%, related to clinical deterioration of a large infarct. In the AG, 4.2% had a periprocedural complication during or after cangrelor infusion, represented by an intracranial hemorrhage in an initially ruptured aneurysm. Favorable clinical outcome was seen in 56.2% and 87.7% of ruptured and unruptured aneurysms, respectively, upon discharge.

CONCLUSIONS

Cangrelor may be a feasible alternative for patients requiring immediate intervention with the use of endoluminal devices. It allows the possibility for a secure transition to long-term ticagrelor and progression to surgery in the setting of unexpected complications.

Woven EndoBridge (WEB) device in the treatment of ruptured aneurysms

BACKGROUND

Wide-necked bifurcation aneurysms (WNBAs) present unique challenges for endovascular treatment. The Woven EndoBridge (WEB) device is an intrasaccular braided device, recently approved by the FDA for treatment of WNBAs. While treatment of intracranial aneurysms with the WEB device has been shown to yield an adequate occlusion rate of 85% at 1 year, few data have been published for patients with ruptured aneurysms.

OBJECTIVE

To present a multi-institutional series depicting the safety and efficacy of using the WEB device as the primary treatment modality in ruptured intracranial aneurysms.

METHODS

A multi-institutional retrospective analysis was conducted, assessing patients presenting with aneurysmal subarachnoid hemorrhage treated with the WEB between January 2014 and April 2020. Baseline demographics, aneurysm characteristics, adverse events, and long-term outcomes (occlusion, re-treatment, functional status) were collected. A descriptive analysis was performed, and variables potentially associated with aneurysm recurrence or re-treatment were assessed.

RESULTS

Forty-eight patients were included. Anterior communicating artery aneurysms were the most common (35.4%) location for treatment, followed by middle cerebral artery (20.8%) and basilar apex (16.7%). Procedural success was noted in 95.8% of patients, and clinically significant periprocedural adverse events occurred in 12.5%. After a median follow-up of 5.5 months, 54.2% of patients had follow-up angiographic imaging. Complete occlusion was seen in 61.5% of cases with adequate occlusion in 92.3%. Re-treatment was required in only 4.2% of patients during the study period. Tobacco use was significantly higher in patients with aneurysm recurrence (88.9% vs 35.7%; p=0.012). No other characteristics were associated with recurrence/re-treatment. At 30 days, 81.1% were functionally independent (modified Rankin Scale score ≤2).

CONCLUSION

Treatment of acutely ruptured aneurysms with the WEB device demonstrates both safety and efficacy on par with rates of conventional treatment strategies.

Neuroform Atlas stent-assisted coiling of ruptured intracranial aneurysms: A multicenter study

PURPOSE

To assess efficacy, safety and to discuss optimal medical therapy of stent-assisted coiling of ruptured intracranial aneurysms.

METHODS

Ruptured intracranial aneurysms treated with stent-assisted coiling in eight different institutions were retrospectively reviewed. Medical treatment regimens varied among the centers, mainly regarding heparin administration and post-procedural single or double antiplatelet therapy. Clinical and angiographic results, including complications and outcomes were analyzed and related to the different therapies.

RESULTS

Sixty-one consecutive patients (male/female 23/38), aged 59.1 years (36-86) underwent stent-assisted coiling for ruptured intracranial aneurysm without antiplatelet pre-medication. Intravenous acetylsalicylic acid (ASA) 500mg was administered to all patients immediately after stent deployment. At the same time heparin was given as bolus in 15 patients (24.6%) as part of local protocol. Intravenous glycoprotein 2b/3a inhibitors (antiGP2b3a) were used as bail-out therapy for stent thrombosis. Stent thrombosis occurred in 22 patients (36.1%), of which 4 (6.5%) lead to incomplete and 18 (29.6) to complete occlusion of the stent. Heparin administration had no effect on thrombosis rate. Thrombosis resolution occurred in all cases with intravenous antiGP2b3a (7 tirofiban, 15 abciximab), without increasing overall complication rate. Single antiplatelet therapy with ASA (28 patients, 45.9%) or double antiplatelet therapy including ASA and clopidogrel (33 patients, 54.1%) were administered after procedure, depending on local protocols and on neurointerventionists' experience. Overall complication rate, including ischemia and hemorrhage was higher in patients in which only ASA was administered (21.4% vs. 12.1%). No late stent thrombosis was seen, regardless of whether a single or double antiplatelet regimen was used. Nevertheless, the small sample size suggests caution in interpreting these results. Moreover, a possible bias may arise from the decision whether to modify the maintenance therapy or not depending on the severity of the intracranial hemorrhage in a case-by-case assessment. At three months, 34 out of 38 patients with HH grade 1-2 (89.4%), and 11 out of 23 with Hunt-Hess grade of 3-4 (47.8%) were independent (Modified Ranking Scale 0-2).

CONCLUSION

Stent assisted coiling of ruptured intracranial aneurysms is a feasible option when simple coiling is not possible. Optimal medical treatment is still controversial because balance between hemorrhagic and ischemic risks is difficult to evaluate. In our series, heparin bolus had no effect on subsequent stent thrombosis. In all cases peri-operative stent thrombosis was successfully managed using bail-out intravenous antiGP2b3a, which did not increase post-procedural hemorrhage rates. A non-significant trend towards increased complications rate was noticed in patients treated with single antiplatelet therapy versus double antiplatelet therapy.

Preclinical Development of a vWF Aptamer to Limit Thrombosis and Engender Arterial Recanalization of Occluded Vessels

Endothelial surface and circulating glycoprotein von Willebrand factor (vWF) regulates platelet adhesion and is associated with thrombotic diseases, including ischemic stroke, myocardial infarction, and peripheral vascular disease. Thrombosis, as manifested in these diseases, is the leading cause of disability and death in the western world. Current parenteral antithrombotic and thrombolytic agents used to treat these conditions are limited by a short therapeutic window, irreversibility, and major risk of hemorrhage. To overcome these limitations, we developed a novel anti-vWF aptamer, called DTRI-031, that selectively binds and inhibits vWF-mediated platelet adhesion and arterial thrombosis while enabling rapid reversal of this antiplatelet activity by an antidote oligonucleotide (AO). Aptamer DTRI-031 exerts dose-dependent inhibition of platelet aggregation and thrombosis in whole blood and mice, respectively. Moreover, DTRI-031 can achieve potent vascular recanalization of platelet-rich thrombotic occlusions in murine and canine carotid arteries. Finally, DTRI-031 activity is rapidly (<5 min) and completely reversed by AO administration in a murine saphenous vein hemorrhage model, and murine toxicology studies indicate the aptamer is well tolerated. These findings suggest that targeting vWF with an antidote-controllable aptamer potentially represents an effective and safer treatment for thrombosis patients having platelet-rich arterial occlusions in the brain, heart, or periphery.

Tiny Pipes: 67 Cases of Flow Diversion for Aneurysms in Distal Vessels Measuring Less Than 2.0 mm

BACKGROUND

Flow diversion is increasingly used for off-label treatments of distal circulation aneurysms. Reports of use in sub-2.0-mm vessels are scant.

METHODS

A prospectively collected, institutional review board-approved cerebral aneurysm database was reviewed to identify patients who underwent flow diversion with a 2.5-mm diameter Pipeline embolization device.

RESULTS

Sixty-seven aneurysms were treated in 67 procedures (66 [99%] successful, 64 [96%] single device, 2 [3%] with 2 devices) in 57 patients. Average age was 56 years and 60% were female. Aneurysm location was 51 (76%) anterior cerebral artery, 14 (21%) middle cerebral artery, and 2 (3%) posterior cerebral artery. Aneurysm size was 4.1 ± 3.0 mm (1-20 mm). Safety outcomes included 3 major strokes (4.5%) resulting in permanent neurologic deficit (modified Rankin Scale score 6,4,4), including 1 mortality (1.5%). Acute stent thrombosis was observed intraprocedurally or within 24 hours of each stroke. There were 2 small-volume (<10 cm³, 40 cm³) dependent intracerebral hemorrhage (3.0%) that resolved without permanent neurologic deficit. For effectiveness, 71% of patients underwent follow-up angiography. Complete occlusion was achieved by 88% at 6 months, 86% at 12 months, and 89% at last follow-up. A slight vessel diameter reduction was apparent on average 6.9 months after the procedure, which was statistically significant at the proximal (P = 0.001) but not distal (P = 0.317) device end. Preoperative average parent vessel diameter was 1.9 mm proximally (range, 1.1-2.6 mm) and 1.7 mm distally (range, 1.0-2.3 mm) of the Pipeline embolization device. Follow-up average vessel diameter was 1.7 mm proximally (range, 0.7-2.4 mm) and 1.6 mm distally (range, 0.6-2.1 mm). Flow delay associated with vessel diameter reduction occurred once. There were no cases of asymptomatic vessel occlusion.

CONCLUSIONS

Flow diversion can be safe and effective for aneurysms originating from vessels <2.0 mm in diameter. Heightened vigilance for the prevention and management of acute stent and vessel thrombosis is warranted in these cases.

Periprocedural Neuroendovascular Antiplatelet Strategies for Thrombosis Prevention in Clopidogrel-Hyporesponsive Patients

Patients undergoing neuroendovascular procedures such as cerebral aneurysm coiling and intracranial stent deployment are frequently treated with antiplatelet agents to prevent thrombotic complications. The combination of aspirin and a P2Y12 inhibitor such as clopidogrel is often initiated days before elective procedures or as loading doses for emergent procedures; however, some patients may still experience thrombotic complications. Patients identified as clopidogrel hyporesponders are more likely to experience poor outcomes and may require changes to their regimens. Historically, high-dose clopidogrel regimens were used in response to subtherapeutic results of platelet function assays and point-of-care testing despite limited supporting data. Recently, more data have emerged using alternative P2Y12 inhibitors such as prasugrel and ticagrelor. Dosing for neuroendovascular conditions is often extrapolated from the cardiac literature, although outcomes in cardiac patients may not be relevant to neurologic patients, making prophylactic treatment recommendations challenging for these patients. This review summarizes the literature for antiplatelet prophylaxis in patients undergoing neuroendovascular device placement, focusing on alternative regimens for clopidogrel hyporesponders.

Safety of tirofiban and dual antiplatelet therapy in treating intracranial aneurysms

Background

Endovascular treatment of intracranial aneurysms usually involves stent-assisted coiling (SAC) and flow diverters. Glycoprotein IIb/IIIa inhibitors such as tirofiban and dual antiplatelet therapy (DAPT) are required to prevent thromboembolic complications afterwards. We sought to determine the safety of tirofiban and DAPT in these cases.

Methods

We conducted a retrospective analysis of our database for patients with intracranial aneurysms who underwent SAC or flow diversion. The tirofiban-DAPT protocol used is described. Data regarding duration of infusion, placement of external ventricular devices (EVDs), complications, haemoglobin levels and platelet count before and 24 hours after antiplatelet therapy were collected and analysed.

Results

One-hundred and forty-one patients with 148 aneurysms/procedures were included. 110 aneurysms were treated acutely and 38 electively. Minor and major haemorrhagic events were recognised in 20% (30/148) aneurysms. Only 5 (3.4%) intracerebral haemorrhages were symptomatic: 3 cortical/SAH and 2 EVD-related. The average blood volume in symptomatic haemorrhages was 24.8 cc versus 5.42 cc in asymptomatic haemorrhages (p=0.002). The rate of EVD-related haemorrhages was 15.7% (19/121) and only 2 (1.7%) were symptomatic. Most haemorrhagic events occurred in ruptured aneurysms (90.1%, p=0.01). No significant change in platelet count or haemoglobin levels before and 24 hours after administration of tirofiban and DAPT was documented. Concomitant administration of heparin did not increase haemorrhagic events.

Conclusion

The use of the GP IIb/IIIa inhibitors tirofiban and DAPT in this series was safe. Tirofiban and DAPT did not affect platelet count or haemoglobin levels and did not increase rate of symptomatic haemorrhages or thromboembolic complications.

Use of Antiplatelet Agents in the Neurosurgical Patient

Antiplatelet agents used to treat neurovascular disease include aspirin; P2Y12 receptor antagonists clopidogrel, prasugrel, and ticagrelor; ADP antagonist ticlopidine; phosphodiesterase inhibitor dipyridamole; and glycoprotein IIb/IIIa inhibitors abciximab, eptifibatide, and tirofiban. Numerous studies have been performed evaluating their efficacy in stroke, extracranial carotid artery disease and dissection, intracranial atherosclerotic disease, and moyamoya disease. The rapid technological advancements in endovascular neurosurgical devices have also made antiplatelet therapy a necessary part of treating intracranial aneurysms. This article presents the relevant data supporting the use of antiplatelet agents in vascular neurosurgery and recommendations based on the described studies.

Myocardial reperfusion with tirofiban injection via aspiration catheter : Efficacy and safety in STEMI patients with large thrombus burden

BACKGROUND

There is no consensus on the use of thrombus aspiration (TA) in primary percutaneous coronary intervention (PPCI), and few studies have focused on the performance of tirofiban via TA catheter after PPCI. Our study investigated the clinical outcome of tirofiban injection through TA in acute ST-segment elevation myocardial infarction (STEMI) patients with large thrombus burden undergoing PPCI treatment.

PATIENTS AND METHODS

The study comprised 122 STEMI patients who underwent TA during PPCI. Participants were randomly divided into two groups. Group A received intravenous tirofiban injection and tirofiban injection via a TA catheter to the infarcted coronary artery after aspiration (n = 61). Group B received intravenous tirofiban injection only (n = 61). Baseline clinical information and follow-up data were collected for both groups. Coronary angiography, electrocardiography, and echocardiography findings as well as major adverse cardiovascular events (MACE) were recorded.

RESULTS

There were significant differences in postprocedural Thrombolysis in Myocardial Infarction (TIMI) grade 2 and 3 flow between the two groups (p = 0.021, p = 0.006, respectively). The incidence of slow-flow in group A was significantly lower than that of group B (p = 0.011). An increased incidence of no ST-segment resolution was observed in group B (p = 0.011). There were fewer major adverse cardiovascular events in group A than in group B, but the difference was not statistically significant.

CONCLUSION

Selective tirofiban injection via TA catheter during PPCI may improve myocardial reperfusion in STEMI patients with large thrombus burden.

Abciximab (ReoPro) Dosing Strategy for the Management of Acute Intraprocedural Thromboembolic Complications during Pipeline Flow Diversion Treatment of Intracranial Aneurysms

Background

Flow diversion with the Pipeline embolization device (PED) is an effective neuro-endovascular method and increasingly accepted for the treatment of cerebral aneurysms. Acute in situ thrombosis is a known complication of PED procedures. There is limited experience in the flow diversion literature on the use of abciximab (ReoPro) for the management of acute thrombus formation in PED cases.

Methods

Data were collected retrospectively on patients who received intra-arterial (IA) ReoPro with or without subsequent intravenous (IV) infusion during PED flow diversion treatment of intracranial aneurysms.

Results

A total of 30 cases in patients with a mean age of 56.7 years (range 36-84) and a mean aneurysm size of 8.6 mm (range 2-25) were identified to have intraprocedural thromboembolic complications during PED treatment. IA ReoPro was administered in all cases, with 20 cases receiving increments of 5-mg boluses and 10 cases receiving a 0.125 mg/kg IA bolus (half cardiac dosing). Complete or partial recanalization was achieved in 100% of the cases. IV ReoPro infusion at 0.125 μg/kg/min for 12 h was administered postprocedurally in 22 cases with a residual thrombus. Postprocedurally, 18 patients were transitioned from clopidogrel (Plavix) to prasugrel (Effient). The majority of the cases (23/30; 77%) were discharged home. Periprocedural intracranial hemorrhage was noted in 2 cases (7%) and radiographic infarct was noted in 4 cases (13%), with an overall mortality of 0% at the time of initial discharge. Clinical follow-up was available for 28/30 patients. The average duration of follow-up was 11.7 months, at which time 23/28 (82%) of the patients had a modified Rankin Scale score of 0.

Conclusions

IA ReoPro administration is an effective and safe rescue strategy for the management of acute intraprocedural thromboembolic complications during PED treatment. Using a dosing strategy of either 5-mg increments or a 0.125 mg/kg IA bolus (half cardiac dosing) can provide high rates of recanalization with low rates of hemorrhagic complications and long-term morbidity.

Antiplatelet Premedication-Free Stent-Assisted Coil Embolization in Acutely Ruptured Aneurysms

OBJECTIVE

Stent-assisted coil embolization (SAC) is one of the treatment options for patients with intracranial aneurysms. The purpose of this study was to assess clinical outcomes of patients who underwent coil embolization for acutely ruptured aneurysms without antiplatelet premedication.

METHODS

A total of 449 patients with acutely ruptured aneurysms underwent endovascular treatment without antiplatelet premedication between April 2006 and October 2015. Among them, 55 patients underwent SAC (SAC group) and 394 underwent coiling without stent assistance (non-SAC group). Periprocedural complications and clinical outcomes at postictal 6 months were compared between the 2 groups.

RESULTS

The rate of hemorrhagic complications showed no significant difference (SAC group vs. non-SAC group, 9.1% vs. 4.8%). Although procedural thromboembolism occurred more frequently in the SAC group (25.5% vs. 12.4%; P = 0.01), poor clinical outcomes (modified Rankin scale score ≥3) were comparable (30.9% vs. 22.1%). In the multivariate analysis, Hunt-Hess grade (odds ratio [OR] = 4.22; P < 0.001), hemorrhagic complications (OR = 4.01; P = 0.018), and age (OR = 1.04, P = 0.001) were independent predictors of poor clinical outcomes, but stent-assisted coil embolization and procedural thromboembolism were not.

CONCLUSIONS

Although procedure-related thromboembolism occurred more frequently, comparable treatment outcomes could be achieved with antiplatelet premedication-free SAC in patients with acutely ruptured aneurysms. The use of stents and thromboembolic complications were not significant risk factors for poor clinical outcome.