Management of antiplatelet therapy in patients undergoing neuroendovascular procedures

Outcome of tailored antiplatelet therapy in carotid stenting: a retrospective comparative study

BACKGROUND

Carotid stenting requires dual antiplatelet therapy to effectively prevent thromboembolic complications. However, resistance to clopidogrel, a key component of this therapy, may lead to persistent risk of these complications. The aim of this study was to determine, if the implementation of routine platelet function testing and adjusting therapy was associated with lower incidence of thromboembolic complications and death.

METHODS

All consecutive patients treated with carotid artery stenting in a single institution over 8 years were enlisted in a retrospective study. Platelet function testing was performed, and efficient antiplatelet therapy was set before the procedure. Incidence of procedure-related stroke or death within periprocedural period (0-30 days) was assessed. The results were evaluated in relation to the findings of six prominent randomized control trials.

RESULTS

A total of 241 patients were treated for carotid stenosis, seven patients undergo CAS on both sides over time. There was 138 symptomatic (55,6%) and 110 asymptomatic stenoses (44,4%). Five thromboembolic complications (2,01%) occurred, four of them (1,61%) was procedure-related. Two patients died because of procedure-related stroke (0,82%). Incidence of procedure-related stroke or death was significant lower compared to the results of CREST study (2,01% vs. 4,81%, P = 0,0243) in the entire cohorts, and to the results of ICSS study in the symptomatic cohorts (2,86% vs. 7,37%, P = 0,0243), respectively.

CONCLUSIONS

Tailored antiplatelet therapy in carotid stenting is safe and seems to be related with lower incidence of procedure-related death or stroke rate. Larger prospective studies to assess whether platelet function testing-guided antiplatelet therapy is superior to standard dual antiplatelet should be considered.

Safety and efficacy of dual antiplatelet therapy combining aspirin and ticagrelor in patients with undergoing intracranial stenting procedures

BACKGROUND

Thromboembolic complications are one of the major periprocedural complications following neuroendovascular procedures. Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel remain the principal agents for prevention of thromboembolic complications. However, clopidogrel resistance is associated with higher risk of thromboembolic complications. This study investigated the safety and efficacy of DAPT with ticagrelor and aspirin in patients undergoing intracranial stenting procedures.

METHODS

This retrospective study was based on patients with intracranial aneurysms who undergoing intracranial stenting procedures at our institution between August 2017 and July 2020. These patients received DAPT with ticagrelor and aspirin were included. DAPT with 90 mg ticagrelor twice daily and aspirin 100 mg daily was continued for 3 months after the intracranial stenting procedure and aspirin continued for 1 year.

RESULTS

In this study, 151 patients were identified. The most common aneurysm location was the internal carotid artery with 127 (71.8%) patients. Of the 151 cases with 160 treated aneurysms, 30 (18.8%) patients were treated by flow diverters (FDs), and 130 (81.2%) by stent-assisted coiling. Five (3.3%) patients had thromboembolic complications. Intraprocedural aneurysmal rupture was observed in one patient because of coil extrusion during coil insertion. None of the patients showed a newly DAPT-related intracerebral hemorrhage. Two patients developed dyspnea, and the symptom resolved without intervention. Furthermore, ecchymoma and gastrointestinal bleeding occurred in one patient respectively. DAPT-related thromboembolic and hemorrhagic complications were not significantly different between the FD group and stent-assisted coiling group.

CONCLUSIONS

In our study, DAPT combining ticagrelor and aspirin seems to be a safe and efficient treatment for preventing thromboembolic complications in patients with intracranial aneurysms, without any increase in hemorrhagic complications. Ticagrelor may be an effective alternative for patients undergoing neurointervention.

Safety and efficacy of tirofiban combined with intravenous thrombolysis and endovascular treatment in acute large vessel occlusion stroke

OBJECTIVE

This study assesses the safety and efficacy of tirofiban for patients with large vessel occlusion stroke after intravenous thrombolysis.

METHODS

This study data was from SUSTAIN, DEVT, and RESCUE BT trials. According to whether the use of tirofiban who underwent endovascular treatment and preceding intravenous thrombolysis was divided into the tirofiban group and the no-tirofiban group. The safety outcomes were symptomatic intracranial hemorrhage, any intracranial hemorrhage within 48 h, and 3-month mortality. The efficacy outcome was defined as a score of 0-2 on the modified Rankin Scale scores at 3 months.

RESULTS

A total of 372 patients with intravenous thrombolysis were included in these SUSTAIN, DEVT, and RESCUE BT trials. Adjusted multivariate analysis showed that tirofiban with intravenous thrombolysis was not associated with symptomatic intracranial hemorrhage (aOR, 0.87; 95 % CI, 0.49-1.57; P=0.65), any intracranial hemorrhage within 48 h (aOR, 1.00; 95 % CI, 0.60-1.66; P=1.00), 3-month mortality (aOR, 1.10; 95 % CI, 0.56-2.19; P=0.78) and 3-month modified Rankin Scale scores 0-2 (aOR, 0.72; 95 % CI, 0.42-1.25; P=0.25) in patients with acute large vessel occlusion. In the subgroup analysis, we found that tirofiban was not recommended for females (aOR, 0.34; 95 % CI, 0.12-0.93), baseline Alberta Stroke Program Early CT Score≤9 (aOR, 0.37; 95 % CI, 0.18-0.76), and cardiogenic embolism (aOR, 0.36; 95 % CI, 0.14-0.97).

CONCLUSION

Tirofiban combined with intravenous thrombolysis in patients with acute large vessel occlusion may be safe. Further studies need to confirm the effectiveness of tirofiban after intravenous thrombolysis in different stroke etiology.

Cost-effectiveness of platelet function testing in dual antiplatelet therapy decision-making after intracranial aneurysm treatment with flow diversion

Dual antiplatelet therapy (DAPT) use is the standard of practice after flow diversion (FD) for intracranial aneurysms (IAs). Yet, no consensus exists in the literature regarding the optimal regimen. Certain institutions utilize various platelet function testing (PFT) to assess patient responsiveness to DAPT. Clopidogrel is the most commonly prescribed drug during DAPT; however, up to 52% of patients can be non-responders, justifying PFT use. Additionally, prices vary significantly among antiplatelet drugs, often further complicated by insurance restrictions. We aimed to determine the most cost-effective strategy for deciding DAPT regimens for patients after IA treatment. A decision tree with Monte Carlo simulations was performed to simulate patients undergoing various three-month postoperative DAPT regimens. Patients were either universally administered aspirin alongside clopidogrel, ticagrelor, or prasugrel without PFT, or administered one of the former thienopyridine medications based on platelet reactivity unit (PRU) results after clopidogrel. Input data for the model were extracted from the current literature, and the willingness-to-pay threshold (WTP) was defined as $100,000 per QALY as per standard practice in the US. The baseline comparison was with universal clopidogrel DAPT without any PFT. Probabilistic and deterministic sensitivity analyses were performed to evaluate the robustness of the model. Utilizing PFT and switching clopidogrel to prasugrel if resistance is documented was the most cost-effective regimen compared to universal clopidogrel, with a base-case incremental cost-effectiveness ratio (ICER) of $-35,255 (cost $2,336.67, effectiveness 0.85). Performing PFT and switching clopidogrel to ticagrelor (ICER $-4,671; cost $2,995.06, effectiveness 0.84), universal prasugrel (ICER $5,553; cost $3,097.30, effectiveness 0.84), or universal ticagrelor (ICER $75,969; cost $3,801.36, effectiveness 0.84) were all more cost-effective than treating patients with universal clopidogrel (cost $3,041.77, effectiveness 0.83). These conclusions remain robust in probabilistic and deterministic sensitivity analyses. The most cost-effective strategy guiding DAPT after FD for IAs is to perform PFTs and switch clopidogrel to prasugrel if resistance is documented, alongside aspirin. The cost of PFT is strongly justified and recommended when deciding patient-specific DAPT regimens.

Clopidogrel Hyperresponsiveness and Hemorrhagic Complications Using On-Label Clopidogrel Dosing after Pipeline Embolization

Introduction: Clopidogrel hyperresponsiveness is a timely topic, with wide ranging reports of hemorrhagic complications, using various clopidogrel dosing strategies following neuroendovascular procedures. This study serves to investigate hemorrhagic complications using standard clopidogrel doses and timing of these complications in relation to the procedure. Materials and Methods: Retrospective cohort of consecutive adult patients undergoing flow diversion with Pipeline Embolization Device (PED) at an academic medical center, receiving on-label clopidogrel doses. Patients with clopidogrel hyperresponsiveness (VerifyNowTM P2Y12 reaction unit (PRU) ≤ 70) were compared to those who were normoresponsive. The primary outcome is the rate of hemorrhagic complications between groups. Results: Of 148 included patients, 54 (36.5%) were identified as clopidogrel hyperresponsive (PRU ≤ 70) and 94 (63.5%) as clopidogrel normoresponsive (PRU 71 - 194). There were no hemorrhagic complications observed in patients who were clopidogrel hyperresponsive, with 5 occurring in patients who were normoresponsive (P = 0.09). Three (60%) of the hemorrhages were intracranial with most occurring intra-procedure or within the first week of the procedure. Age > 60 years was the only candidate predictor for hemorrhagic complications (P = 0.004). Conclusion: Our findings are contradictory, with lower hemorrhagic complications in clopidogrel hyperresponders than prior literature, and most occurring intra-op or in the immediate acute post-op phase.

Dual Antiplatelet Non-Responder: Resistance to Clopidogrel and Ticagrelor

Background

Dual antiplatelet therapy is often required for neurointerventional procedures, especially when a stent or flow diverter is placed in the cervical and intracranial vessels. Patients are usually started on aspirin and clopidogrel given the simplicity of the once daily regimen with reasonable cost. Unfortunately, about a third of patients do not show the desired antiplatelet response to clopidogrel and another agent needs to be introduced. Ticagrelor is a potent antiplatelet medication that has a favorable pharmacological profile and has emerged as a reliable alternative to clopidogrel in recent years. Despite ticagrelor non-responders being rare, they do exist, and identification of these patients is important.

Results

A 74-year-old female was incidentally found to harbor a right posterior communicating aneurysm which was successfully treated electively with stent-assisted coiling. Platelet inhibition testing revealed non-responsiveness to Clopidogrel. Ticagrelor was initiated but the patient's platelet reactivity unit remained in the normal range. Management algorithms to maximize a patient's ticagrelor response by facilitating enteral absorption were applied but no platelet inhibition was achieved. The patient was eventually identified as a true ticagrelor non-responder.

Conclusion

Resistance to antiplatelet medication can result in devastating complications with permanent neurological deficits. Ticagrelor non-responders are rare but do exist. Platelet inhibition testing should be part of the preprocedural workup for neurointerventions.

Variability patterns in dual antiplatelet therapy following endovascular repair of intracranial aneurysms: Insight into regimen heterogeneity and the need for a consensus

This comprehensive review delves into the evolving field of neurointervention for intracranial aneurysms, exploring the critical adjunct of Dual Antiplatelet Therapy (DAPT) to endovascular coiling, stent-assisted coiling (SAC), flow-diversion stents, and flow-disruption (intrasaccular) devices. Despite growing evidence supporting the success of DAPT in reducing thromboembolic events, the lack of consensus on optimal regimens, doses, and duration is evident. Factors contributing to this variability include genetic polymorphisms affecting treatment response and ongoing debates regarding the clinical significance of hemorrhagic complications associated with DAPT. This review analyzes pre- and post-procedural antiplatelet usage across various interventions. The imperative lies in ongoing research to define optimal DAPT durations, ensuring a nuanced approach to the delicate balance between thrombosis and hemorrhage in intracranial aneurysm management.

Comparing the Impact of Stenting vs. Medical Therapy for Intracranial Arterial Stenosis : A Systematic Review and One-stage and Two-stage Meta-Analysis of Randomized Clinical Trials

PURPOSE

In the treatment of intracranial arterial stenosis (ICAS), controversies remain regarding the optimal treatment strategy. Our study aims to conduct an individual patient-level data meta-analysis of existing RCTs comparing PTAS versus best medical therapy and to identify differences in outcomes such as incidence of ischemic stroke or death.

METHODS

Randomised controlled trials comparing the outcomes of stenting versus best medical therapy for patients who had symptomatic ICAS of >50%. Excluded studies included case reports, case series, reviews, observational studies,  letters or studies evaluating isolated angioplasty techniques without stenting. Data was extracted in accordance with PRISMA guidelines.

RESULTS

7 studies involving 1425 participants were included. There was an increased risk in the incidence of stroke and death within the first 30 days post-procedure for patients treated with PTAS over best medical therapy (RR = 2.22 [1.28-3.86], I² = 0%). Patients who underwent stenting also had a significantly higher risk of intracranial haemorrhage (RR = 12.66 [2.41-66.45], I² = 0%) and death (RR = 5.41 [1.20-24.28], I² = 0%).Under the shared frailty model, stenting when compared to medical therapy has a HR of 1.81 (95% CI:1.25-2.6) of stroke or death across 1 year. Under the parametric Royston-Parmar model, stenting has a significant decrease in the RMST(-0.83 months; 95% CI: -1.30-0.37). Stenting continued to show worse outcomes up to the 3 year mark with a HR of 1.60 (95% CI: 1.11-2.32).

CONCLUSIONS AND RELEVANCE

There is an increased risk of peri- and post-procedural stroke and death over best medical therapy in patients with symptomatic ICAS who undergo PTAS. Further work is required to refine patient selection and mitigate peri-procedural risks.

Safety and efficacy of stent-assisted coil embolization with periprocedural dual antiplatelet therapy for the treatment of acutely ruptured intracranial aneurysms

PURPOSE

Despite growing evidence for the effectiveness of stent-assisted coil embolization (SAC) in treating acutely ruptured aneurysms, the safety of stent placement in acute phase remains controversial because of concerns for stent-induced thromboembolism and hemorrhagic events attributable to the necessity of antiplatelet therapy. Therefore, we investigated the safety and efficacy of SAC with periprocedural dual antiplatelet therapy (DAPT) compared with the coiling-only technique to determine whether it is a promising treatment strategy for ruptured aneurysms.

METHODS

We retrospectively evaluated 203 enrolled patients with acutely ruptured aneurysms, categorizing them into two groups: SAC and coiling-only groups. Comparative analyses between the two groups regarding angiographic results, clinical outcomes, and procedure-related complications were performed. A subgroup analysis of procedural complications was conducted on patients who did not receive chronic antithrombotic medications to alleviate their influence before hospitalization.

RESULTS

130 (64.0%) patients were treated using the coiling-only technique, whereas 73 (36.0%) underwent SAC. There was a trend to a higher complete obliteration rate (p = 0.061) and significantly lower recanalization rate (p = 0.030) at angiographic follow-up in the SAC group compared to the coiling-only group. Postprocedural cerebral infarction occurred less frequently in the SAC group (8.2%) than in the coiling-only group (17.7%), showing a significant difference (p = 0.044). Although the ventriculostomy-related hemorrhage rate was significantly higher in the SAC group than in the coiling-only group (26.2% vs. 9.3%, p = 0.031), the incidence of symptomatic ventriculostomy-related hemorrhage was comparable. Subgroup analysis excluding patients receiving chronic antithrombotic medications showed similar results.

CONCLUSION

SAC with periprocedural DAPT could be a safe and effective treatment strategy for acutely ruptured aneurysms. Moreover, it might have a protective effect on postprocedural cerebral infarction without increasing the risk of symptomatic hemorrhagic complications.

Racial differences in P2Y12 inhibitor responsiveness in patients undergoing neuro-endovascular procedures: A cohort from the Middle East

BACKGROUND

Data on P2Y12 inhibitors responsiveness from the middle east is scarce. We sought to investigate patient responsiveness to P2Y12 inhibitors within a cohort of major races that characterize the UAE population. The secondary objective was to assess risk factors for hyper and hypo-responsiveness in this population.

METHODS

We conducted a cross-sectional study on adults who received either clopidogrel or ticagrelor treatments and had platelet responsiveness testing before undergoing neuro-endovascular interventions at our quaternary care hospital between March 2015 and April 2019.

RESULTS

During the study period, 249 subjects met the inclusion criteria. Overall, 17.3 % were hyper-responsive and 25.7 % were hypo-responsive to P2Y12 inhibitors. When comparing between the P2Y12 inhibitors, rates of hyper-responsiveness were significantly higher to ticagrelor when compared to clopidogrel (11 versus 6 %, p = 0.02 respectively). Contrarily, hypo-responsiveness rates were significantly higher in clopidogrel treated patients compared to their ticagrelor treated counterparts (23 versus 2 %, p < .001 respectively). Patients of Middle-Eastern origin showed a significantly higher rate of hypo-responsiveness to both clopidogrel and ticagrelor when compared to other races (41.1 % and 26.7 %, P < 0.001 respectively). Asians showed the highest rates of hyper-responsiveness for both agents. Multivariate logistic regression analysis showed that proton pump inhibitors and statin combination, (OR: 6.39, 95 %CI [1.60, 25.392]), and Middle East vs. Indian subcontinent patients (OR: 4.67, 95 %CI [1.79-12.14]) were independent predictors of hypo-responsiveness to both P2Y12 inhibitors.

CONCLUSION

This study demonstrated a high rate of hypo-responsiveness to P2Y12 inhibitors in a UAE cohort of patients undergoing neuro-endovascular procedures. In addition, therapeutic responsiveness to P2Y12 inhibitors varied markedly based on the racial background. Future larger studies are needed to evaluate genetic variations that may contribute to this rate of hypo-responsiveness in our population.

Duration of dual-antiplatelet therapy after stent-assisted coil for unruptured intracranial aneurysm: A nationwide cohort study

BACKGROUND

Stent-assisted coil (SAC) is increasingly used to treat unruptured intracranial aneurysm (UIA). However, the optimal duration of dual-antiplatelet therapy (DAPT) after SAC insertion remains unknown.

AIM

To assess the time-dependent effect of DAPT on the risk of ischemic and hemorrhagic complications after SAC.

METHODS

This is a retrospective cohort study among patients with UIA treated with SAC using the nationwide health claims database in South Korea between 2009 and 2020. Multivariate Cox regression analysis was used, which included the use of DAPT as a time-dependent variable. The effect of DAPT was investigated for each period of "within 90 days," "91 to 180 days," "181 to 365 days," and "366 to 730 days" after SAC. The primary outcome was a composite of ischemic stroke and major bleeding in each period within two years after SAC.

RESULTS

Of the 15,918 patients, mean age at SAC was 57.6 ± 10.8 years, and 3815 (24.0%) were men. The proportion of patients on DAPT was 79.4% at 90 days, 58.3% at 180 days, and 28.9% at 1 year after SAC. During the 2 years after SAC, the primary composite outcome occurred in 356 patients (2.2%). DAPT significantly reduced the primary composite outcome within 90 days after SAC (adjusted hazard ratio (aHR), 0.44; 95% confidence interval (CI), 0.28-0.69; p < 0.001); however, this was not the case after 90 days (all p > 0.05). DAPT reduced ischemic stroke risk within 90 days (aHR, 0.31; 95% CI 0.18-0.54; p < 0.001), and 91 to 180 days after SAC (aHR 0.40; 95% CI 0.18-0.88; p = 0.022); however, after 180 days, DAPT was no longer beneficial.

CONCLUSIONS

In patients with UIA treated with SAC, 3 months of DAPT was associated with a decreased risk of the composite of ischemic and hemorrhagic complications.

Multicenter Comparison of the Safety and Efficacy of Clopidogrel Versus Ticagrelor for Neuroendovascular Stents

BACKGROUND

Dual antiplatelet therapy (DAPT) is commonly employed for neuroendovascular stenting due to the significant risk of thromboembolism. Clopidogrel and aspirin are most often selected as initial DAPTs; however, there is limited literature available to support guidance of DAPT in this setting. The objective of this study was to evaluate safety and efficacy in patients whose final regimen included either DAPT with aspirin and clopidogrel (DAPT-C) or DAPT with aspirin and ticagrelor (DAPT-T).

METHODS

This was a multicenter, retrospective cohort of patients who underwent neuroendovascular stenting and received DAPT between July 1, 2017, and October 31, 2020. Study participants were allocated into groups based on discharge DAPT regimen. The primary outcome was incidence of stent thrombosis at 3-6 months on DAPT-C versus DAPT-T, as defined by the presence of thrombus on imaging or new onset stroke. Secondary outcomes included major and minor bleeding and death within 3-6 months after the procedure.

RESULTS

Five hundred and seventy patients were screened across 12 sites. Of those, 486 were included (DAPT-C n = 360, DAPT-T n = 126). There was no difference in the primary outcome of stent thrombosis between the DAPT-C and DAPT-T groups (8% vs. 8%, p = 0.97) and no difference in any of the secondary safety outcomes.

CONCLUSIONS

Using DAPT-C or DAPT-T regimens in a broad population of neuroendovascular stenting procedures appears to have similar safety and efficacy profiles. Further prospective evaluation is warranted to streamline the practice of DAPT selection and monitoring to determine the impact on clinical outcomes.

Management of giant internal carotid aneurysm by extracranial-intracranial bypass and flow diverter stent

Flow diverter stents have become the standard approach to managing intracranial aneurysms; however, in some cases of complex, wide-necked aneurysms, poor outcomes due to stent occlusion have been reported. We report the case of a giant internal carotid artery aneurysm treated by high-flow extracranial-intracranial (EC-IC) bypass with flow diverter deployment. Seven months post-operatively, radiographic imaging demonstrated occlusion of the stent and parent artery, with further ischemic events prevented by collateral flow from the high flow bypass. This case demonstrates the continued utility of EC-IC bypass in the endovascular era, especially as a rescue tool in cases of delayed stent occlusion.

Management strategies of unanticipated intracranial stenosis during mechanical thrombectomy for acute stroke: A survey of academic neurointerventionalists

BACKGROUND

The optimal approach to the management of intracranial atherosclerotic disease (ICAD) at the time of mechanical thrombectomy (MT) for large vessel occlusion (LVO) remains controversial. The goal of this study is to characterize current practices concerning this challenging clinical situation in a survey of practicing neurointerventionalists.

METHODS

An electronic questionnaire was sent to a cross-section of North American academic neurointerventionalists using publicly available contact information and departmental websites. Prior to analysis, responses were anonymized and categorized by region.

RESULTS

A total of 136/360 responses were recorded from the U.S. and Canada. The mean number of years of practicing as a neurointerventionalist among the respondents was 10.5 (± 6.2 years). ICAD was perceived as a causative factor during MT for LVO in 5-10% of thrombectomy cases. The most common first-line treatment approach for significant ICAD, assuming a TICI 2b or better reperfusion, was medical therapy (77.9% of respondents), followed by angioplasty + stent placement (8.8% of respondents). There were no significant differences in the first line treatment of ICAD in LVO between geographical regions (p = 0.815).

CONCLUSION

The approach to underlying ICAD in LVO varies widely; however, the majority of neurointerventionalists prefer medical therapy with DAPT as a first-line treatment approach. The current survey highlights the need for studies that better define the optimal timing and modality of treatment, along with an evidence-based framework for balancing the risks associated with these treatment approaches.

Effect of Chronic Anticoagulation on Outcomes of Endovascular Treatment for Unruptured Intracranial Aneurysms-A Propensity-Matched Multicenter Study

BACKGROUND AND OBJECTIVES

Endovascular treatment of unruptured intracranial aneurysms (UIAs) in patients receiving anticoagulant medications has not been well studied. Whether long-term anticoagulation (AC) use affects aneurysmal obliteration rates and treatment-related complications is unclear.

METHODS

Patients with endovascular treatment for UIA from 4 academic centers were identified and divided into AC and non-AC groups. Periprocedural complications, radiographic and clinical outcomes, and retreatment rates were compared between the 2 groups before and after propensity score matching.

RESULTS

The initial cohort consisted of 70 patients in the AC group and 355 in the non-AC group. After one-to-one nearest neighbor propensity matching, 38 pairs of patients were compared for periprocedural complications. The total number of complications were higher in the AC group yet not significant (18.4% vs 5.3%, P = .15). After adding imaging follow-up duration to matched variables, 36 pairs were obtained. There was no significant difference in Raymond-Roy occlusion rate between the 2 groups ( P = .74). However, retreatment rate trended higher in the AC group compared with the non-AC group (22.2% vs 5.6%, P = .09). When clinical follow-up duration was added among matched variables, 26 pairs of cases were obtained for long-term clinical outcomes. There was no significant difference in modified Rankin Scale score between the 2 groups ( P = .61). One-to-many nearest neighbor propensities matched analysis with bigger sample sizes yielded similar results.

CONCLUSION

The use of anticoagulants does not affect occlusion rates or long-term outcomes in endovascular treatment of UIAs. Retreatment rates were higher in the AC group; however, this was not statistically significant.

Antiplatelets and antithrombotics in neurointerventional procedures: Guideline update

BACKGROUND

Antiplatelet and antithrombotic medication management before, during, and after neurointerventional procedures has significant practice variation. This document updates and builds upon the 2014 Society of NeuroInterventional Surgery (SNIS) Guideline 'Platelet function inhibitor and platelet function testing in neurointerventional procedures', providing updates based on the treatment of specific pathologies and for patients with specific comorbidities.

METHODS

We performed a structured literature review of studies that have become available since the 2014 SNIS Guideline. We graded the quality of the evidence. Recommendations were arrived at through a consensus conference of the authors, then with additional input from the full SNIS Standards and Guidelines Committee and the SNIS Board of Directors.

RESULTS

The management of antiplatelet and antithrombotic agents before, during, and after endovascular neurointerventional procedures continues to evolve. The following recommendations were agreed on. (1) It is reasonable to resume anticoagulation after a neurointerventional procedure or major bleeding episode as soon as the thrombotic risk exceeds the bleeding risk in an individual patient (Class I, Level C-EO). (2) Platelet testing can be useful to guide local practice, and specific approaches to using the numbers demonstrate marked local variability (Class IIa, Level B-NR). (3) For patients without comorbidities undergoing brain aneurysm treatment, there are no additional considerations for medication choice beyond the thrombotic risks of the catheterization procedure and aneurysm treatment devices (Class IIa, Level B-NR). (4) For patients undergoing neurointerventional brain aneurysm treatment who have had cardiac stents placed within the last 6-12 months, dual antiplatelet therapy (DAPT) is recommended (Class I, Level B-NR). (5) For patients being evaluated for neurointeventional brain aneurysm treatment who had venous thrombosis more than 3 months prior, discontinuation of oral anticoagulation (OAC) or vitamin K antagonists should be considered as weighed against the risk of delaying aneurysm treatment. For venous thrombosis less than 3 months in the past, delay of the neurointerventional procedure should be considered. If this is not possible, see atrial fibrillation recommendations (Class IIb, Level C-LD). (6) For patients with atrial fibrillation receiving OAC and in need of a neurointerventional procedure, the duration of TAT (triple antiplatelet/anticoagulation therapy=OAC plus DAPT) should be kept as short as possible or avoided in favor of OAC plus single antiplatelet therapy (SAPT) based on the individual's ischemic and bleeding risk profile (Class IIa, Level B-NR). (7) For patients with unruptured brain arteriovenous malformations there is no indication to change antiplatelet or anticoagulant management instituted for management of another disease (Class IIb, Level C-LD). (8) Patients with symptomatic intracranial atherosclerotic disease (ICAD) should continue DAPT following neurointerventional treatment for secondary stroke prevention (Class IIa, Level B-NR). (9) Following neurointerventional treatment for ICAD, DAPT should be continued for at least 3 months. In the absence of new stroke or transient ischemic attack symptoms, reversion to SAPT can be considered based on an individual patient's risk of hemorrhage versus ischemia (Class IIb, Level C-LD). (10) Patients undergoing carotid artery stenting (CAS) should receive DAPT before and for at least 3 months following their procedure (Class IIa, Level B-R). (11) In patients undergoing CAS during emergent large vessel occlusion ischemic stroke treatment, it may be reasonable to administer a loading dose of intravenous or oral glycoprotein IIb/IIIa or P2Y12 inhibitor followed by maintenance intravenous infusion or oral dosing to prevent stent thrombosis whether or not the patient has received thrombolytic therapy (Class IIb, C-LD). (12) For patients with cerebral venous sinus thrombosis, anticoagulation with heparin is front-line therapy; endovascular therapy may be considered particularly in cases of clinical deterioration despite medical therapy (Class IIa, Level B-R).

CONCLUSIONS

Although the quality of evidence is lower than for coronary interventions due to a lower number of patients and procedures, neurointerventional antiplatelet and antithrombotic management shares several themes. Prospective and randomized studies are needed to strengthen the data supporting these recommendations.

Management of posterior circulation tandem occlusions in acute ischemic stroke: Recanalize the dominant vertebral artery with priority

PURPOSE

To illustrate the characteristics of acute ostial vertebral artery (VA) and basilar artery (BA) tandem occlusions. The endovascular treatment strategy for ostial VA-BA tandem occlusion was reported.

MATERIALS AND METHODS

We conducted a retrospective analysis of patients with ostial VA-BA tandem occlusion who underwent endovascular treatment in our center between November 2018 and February 2022. We preferred to recanalize the dominant vertebral artery with priority. The imaging characteristics, treatment strategy, clinical outcomes, and complications were analyzed.

RESULTS

In total, 9 patients with ostial VA-BA tandem occlusion were enrolled in this study. All the VA-BA tandem occlusion was caused by acute occlusion of the dominant VA. Endovascular revascularization was performed through the occluded dominant VA in 8 patients and was performed through contralateral non-dominant VA in 1 patient. Successful recanalization (mTICI 2b/3 grade) was achieved in all 9 patients, and 5 patients (55.5%) achieved functional independence with a mRS score of 0-2 at 90 days.

CONCLUSIONS

In this case series, the occurrence of ostial VA-BA tandem occlusions was mainly caused by acute occlusion of the dominant VA. Endovascular revascularization of ostial VA-BA tandem occlusions through occluded dominant VA was feasible and recommended.

Artificial Intelligence and Neurosurgery: Tracking Antiplatelet Response Patterns for Endovascular Intervention

Platelets play a critical role in blood clotting and the development of arterial blockages. Antiplatelet therapy is vital for preventing recurring events in conditions like coronary artery disease and strokes. However, there is a lack of comprehensive guidelines for using antiplatelet agents in elective neurosurgery. Continuing therapy during surgery poses a bleeding risk, while discontinuing it before surgery increases the risk of thrombosis. Discontinuation is recommended in neurosurgical settings but carries an elevated risk of ischemic events. Conversely, maintaining antithrombotic therapy may increase bleeding and the need for transfusions, leading to a poor prognosis. Artificial intelligence (AI) holds promise in making difficult decisions regarding antiplatelet therapy. This paper discusses current clinical guidelines and supported regimens for antiplatelet therapy in neurosurgery. It also explores methodologies like P2Y12 reaction units (PRU) monitoring and thromboelastography (TEG) mapping for monitoring the use of antiplatelet regimens as well as their limitations. The paper explores the potential of AI to overcome such limitations associated with PRU monitoring and TEG mapping. It highlights various studies in the field of cardiovascular and neuroendovascular surgery which use AI prediction models to forecast adverse outcomes such as ischemia and bleeding, offering assistance in decision-making for antiplatelet therapy. In addition, the use of AI to improve patient adherence to antiplatelet regimens is also considered. Overall, this research aims to provide insights into the use of antiplatelet therapy and the role of AI in optimizing treatment plans in neurosurgical settings.

Use of the Neuroform Atlas stent for wide-necked cerebral aneurysms

To investigate the effect and safety of the Neuroform Atlas (NFA) stent in stent-assisted coiling of wide-necked intracranial aneurysms, patients with wide-necked intracranial aneurysms were retrospectively enrolled and treated with the NFA stent-assisted coiling. The modified Rankin scale (mRS) grades and Raymond grades were used to assess the clinical outcomes and aneurysm occlusion degrees, respectively, after embolization and at follow-up. Totally, 122 patients were enrolled with 129 wide-necked aneurysms, and forty-nine (40.2%) patients experienced subarachnoid hemorrhage. A total of 134 NFA stents were deployed in all patients. Immediately after endovascular embolization, the Raymond grade was I in 112 (86.8%), II in 8 (6.2%), and III in 9 (7.0%). Complications occurred in 7 (5.7%) patients, including stent displacement in 2 (1.6%) patients, thrombosis and cerebral infarction in 4 (3.3%), and death in 1 (0.8%). Clinical follow-up was performed in 113 (92.6%) patients 6-30 (mean 21) months after embolization, with the mRS grade 0 in 99 (87.6%) patients, 1 in 7 (6.2%), 2 in 5 (4.4%), and 3 in 2 (1.8%). Good prognosis (mRS ≤ 2) was achieved in 111 (98.2%) patients while poor prognosis (mRS > 2) in two (1.8%). Digital subtraction angiography was conducted in 98 (80.3%) patients with 104 (80.6%) aneurysms 6-30 (mean 21) months after embolization. The Raymond grade was grade I in 94 (90.4%) aneurysms, II in 4 (3.8%), and III in 6 (5.8%). Compared with the Raymond grades immediately after embolization, 93 (89.4%) aneurysms disappeared, 9 (8.7%) remained unchanged in the occlusion status, and 2 (1.9%) were recurrent. In conclusion, the NFA stent may have a high aneurysm occlusion rate and a low complication rate in assisting coiling of wide-necked intracranial aneurysms even though further studies are necessary to prove this.

Ticagrelor versus clopidogrel after intracranial stent angioplasty: a real-world study

Objective

It was unknown whether a regimen of aspirin plus ticagrelor (aspirin-ticagrelor) attenuates ischemic vascular events without increasing bleeding risk in patients who had undergone intracranial stenting compared with an aspirin plus clopidogrel (aspirin-clopidogrel) regimen. This article compares the efficacy and safety outcomes of the two double antibody regimens in patients undergoing intracranial stent and investigates whether aspirin-ticagrelor could be an alternative antiplatelet agent without increasing the risk of bleeding.

Methods

We conducted a retrospective analysis of our database for patients who had undergone intracranial stenting. From January 2017 to May 2021, consecutive patients treated with endovascular stenting were identified and dichotomized by whether aspirin-ticagrelor or aspirin-clopidogrel were used. The outcomes were compared by propensity score matching.

Results

A total of 340 patients treated with intracranial stent were included. Of all, 132 patients were matched. At 180 days, ischemic vascular events occurred in one patient (1.5%) in the aspirin-ticagrelor group and in six patients (9.1%) in the aspirin-clopidogrel group. Although the absolute incidence of ischemic vascular events [1.5% (1/66) vs. 9.1% (6/66), p = 0.125] was lower in the aspirin-ticagrelor group than in the aspirin-clopidogrel group, there were no statistical differences. There were no statistical differences in ischemic vascular events, ischemic stroke, or death up to 180 days between the two groups. In addition, the incidence of bleeding did not differ. No intracranial hemorrhage or mild bleeding occurred. No statistically significant difference was noted in restenosis and symptomatic restenosis at follow-up.

Conclusion

In our study involving patients with acute ischemic stroke who had undergone intracranial stenting, aspirin-ticagrelor was not found to be superior to aspirin-clopidogrel in reducing the rate of ischemic vascular events. The risk of bleeding did not differ between the two groups. Aspirin-ticagrelor does not lower total restenosis and symptomatic restenosis risk at follow-up.

Trends in Dual Antiplatelet Therapy Use for Neurointerventional Procedures for the Management of Intracranial Aneurysms

The use of periprocedural dual antiplatelet therapy (DAPT) has significantly evolved along with innovations in the endovascular management of intracranial aneurysms. Historically, aspirin and clopidogrel have been the most commonly employed regimen due to its safety and efficacy. However, recent studies highlight the importance of tailoring DAPT regimens to individual patient characteristics which may affect clopidogrel metabolism, such as genetic polymorphisms. In the present report, a systematic review of the literature was performed to determine optimal antiplatelet use with flow diverting stents, intracranial stents, intrasaccular devices, and stent-assisted coiling. Studies were analyzed for the number of aneurysms treated, DAPT regimen, and any thromboembolic complications. Based on inclusion criteria, 368 studies were selected, which revealed the increasing popularity of alternative DAPT regimens with the aforementioned devices. Thromboembolic or hemorrhagic complications associated with antiplatelet medications were similar across all medications. DAPT with ticagrelor, tirofiban, or prasugrel are effective and safe alternatives to clopidogrel and do not require enzymatic activation. Further clinical trials are needed to evaluate different antiplatelet regimens with various devices to establish highest-level evidence-based guidelines and recommendations.

Roles of light transmission aggregometry and CYP2C19 genotype in predicting ischaemic complications during interventional therapy for intracranial aneurysms

BACKGROUND AND PURPOSE

Light transmission aggregometry (LTA) and CYP2C19 genotype analysis are commonly used to evaluate the antiplatelet effects of clopidogrel during the interventional treatment of intracranial aneurysms. The aim of this study was to determine which test can predict ischaemic events during these treatments.

METHODS

Patient demographic information, imaging data, laboratory data and ischaemic complications were recorded. LTA and CYP2C19 genotype results were compared, and multiple linear regression was performed to examine factors related to platelet reactivity. Multivariate regression analysis was performed to determine whether LTA and CYP2C19 could predict ischaemic complications and to identify other clinical risk factors. Receiver operating characteristic curve analysis was conducted to calculate the cut-off value for predicting ischaemic complications. A subgroup analysis was also performed for different CYP2C19 genotype metabolisers, as well as for patients with flow diverters and traditional stents.

RESULTS

A total of 379 patients were included, of which 22 developed ischaemic events. Maximum platelet aggregation induced by ADP (ADP-MPA) could predict ischaemic events (p<0.001; area under the curve, 0.752 (95% CI 0.663 to 0.842)), and its cut-off value was 41.5%. ADP-MPA (p=0.001) and hypertension duration >10 years (p=0.022) were independent risk factors for ischaemic events, while the CYP2C19 genotype was not associated with ischaemic events. In the subgroup analysis, ADP-MPA could predict ischaemic events in fast metabolisers (p=0.004) and intermediate metabolisers (p=0.003). The cut-off value for ischaemic events was lower in patients with flow diverters (ADP-MPA=36.4%) than in patients with traditional stents (ADP-MPA=42.9%).

CONCLUSIONS

ADP-MPA can predict ischaemic complications during endovascular treatment of intracranial aneurysms. Patients with flow diverters require stronger antiplatelet medication than patients with traditional stents.

Effect of Platelet Function Testing Guidance on Clinical Outcomes for Patients with Intracranial Aneurysms Undergoing Endovascular Treatment

BACKGROUND

Platelet function testing has been proposed to better adjust individualized antiplatelet treatment for patients undergoing endovascular treatment for intracranial aneurysms. Its clinical significance needs to be comprehensively evaluated.

PURPOSE

Our aim was to evaluate the impact of platelet function testing-guided versus standard antiplatelet treatment in patients receiving endovascular treatment for intracranial aneurysms.

DATA SOURCES

PubMed, EMBASE, and the Cochrane Library of clinical trials were searched from inception until March 2023.

STUDY SELECTION

Eleven studies comprising 6199 patients were included.

DATA ANALYSIS

ORs with 95% CIs were calculated using random effects models.

DATA SYNTHESIS

The platelet function testing-guided group was associated with a decreased rate of symptomatic thromboembolic events (OR = 0.57; 95% CI, 0.42-0.76; I2 = 26%). No significant difference was found in asymptomatic thromboembolic events (OR = 1.07; 95% CI, 0.39-2.94; I2 = 48%), hemorrhagic events (OR = 0.71; 95% CI, 0.42-1.19; I2 = 34%), intracranial hemorrhagic events (OR = 0.61; 95% CI, 0.03-10.79; I2 = 62%), morbidity (OR = 0.53; 95% CI, 0.05-5.72; I2 = 86%), and mortality (OR = 1.96; 95% CI, 0.64-5.97; I2 = 0%) between the 2 groups. Subgroup analysis suggested that platelet function testing-guided therapy may contribute to fewer symptomatic thromboembolic events in patients who received stent-assisted coiling (OR = 0.43; 95% CI, 0.18-1.02; I2 = 43%) or a combination of stent-assisted and flow-diverter stent placement (OR = 0.61; 95% CI, 0.36-1.02; I2 = 0%) or who changed from clopidogrel to other thienopyridines (OR = 0.64; 95% CI, 0.40-1.02; I2 = 18%), though the difference did not reach statistical significance.

LIMITATIONS

Heterogeneous endovascular treatment methods and adjusted antiplatelet regimens were limitations.

CONCLUSIONS

Platelet function testing-guided antiplatelet strategy significantly reduced the incidence of symptomatic thromboembolic events without any increase in the hemorrhagic events for patients undergoing endovascular treatment for intracranial aneurysms.

The 2023 Taiwan Stroke Society Guidelines for the management of patients with intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is a major cause of ischemic stroke, especially in Asian populations, which has a high risk of recurrent stroke and cardiovascular comorbidities. The present guidelines aim to provide updated evidence-based recommendations for diagnosis and management of patients with ICAD. Taiwan Stroke Society guideline consensus group developed recommendations for management of patients with ICAD via consensus meetings based on updated evidences. Each proposed class of recommendation and level of evidence was approved by all members of the group. The guidelines cover six topics, including (1) epidemiology and diagnostic evaluation of ICAD, (2) nonpharmacological management of ICAD, (3) medical therapy for symptomatic ICAD, (4) endovascular thrombectomy and rescue therapy for acute ischemic stroke with underlying ICAD, (5) endovascular interventional therapy for postacute symptomatic intracranial arterial stenosis, and (6) surgical treatment of chronic symptomatic intracranial arterial stenosis. Intensive medical treatment including antiplatelet therapy, risk factor control, and life style modification are essential for patients with ICAD.

Single antiplatelet regimen in flow diverter treatment of cerebral aneurysms: The drug matters. A systematic review and meta-analysis

BACKGROUND

Hemorrhagic and thromboembolic complications (TECs) are the main concerns in the endovascular treatment of intracranial aneurysms using flow diverter devices (FDs). The clinical demand for single antiplatelet therapy (SAPT) is increasing especially with the development of devices with lower thrombogenicity profile. However, the safety of SAPT is not well established.

OBJECTIVE

To analyze the safety and efficacy of SAPT in terms of ischemic and hemorrhagic complications in patients undergoing FDs treatment for cerebral aneurysms.

METHODS

A systematic literature search and meta-analysis were conducted in PubMed, Ovid MEDLINE, Ovid Embase, and Web of Science from January 2010 until October 2022. Twelve articles which reported SAPT and data on hemorrhagic, TECs, and mortality following FDs treatment were included.

RESULTS

Overall, the 12 studies involved 237 patients with 295 aneurysms. Five investigated the safety and efficacy of SAPT in 202 unruptured aneurysms. Six studies focused on 57 ruptured aneurysms. One study included both ruptured and unruptured aneurysms. Among the 237 patients, prasugrel was most often used as SAPT in 168 cases (70.9%), followed by aspirin in 42 (17.7%) patients, and by ticagrelor in 27 (11.4%). Overall, the hemorrhagic complication rate was 0.1% (95% CI 0% to 1.8%). The TEC rate was 7.6% (95% CI 1.7% to 16.1%). In the subgroup analysis, the TEC rates of prasugrel monotherapy of 2.4% (95% CI 0% to 9.3%) and ticagrelor monotherapy of 4.2% (95% CI 0.1% to 21.1%) were lower than of aspirin monotherapy 20.2% (95% CI 5.9% to 38.6%). The overall mortality rate was 1.3% (95% CI 0% to 6.1%).

CONCLUSION

According to the available data, SAPT regimen in patients undergoing FDs treatment for cerebral aneurysms has an acceptable safety profile, especially with the use of ADP-receptor antagonists.

Antiplatelet therapy adjustment improved the radiomic characteristics of acute silent cerebral infarction after stent-assisted coiling in patients with high on-treatment platelet reactivity: A prospective study

Background

We aimed to investigate the effects of high on-treatment platelet reactivity (HPR) and antiplatelet therapy adjustment on high-risk radiomic features in patients with antiplatelet therapy adjustment on acute silent cerebral infarction (ASCI) who had unruptured intracranial aneurysms (UIA) after stent placement.

Methods

This single-institution study prospectively included 230 UIA patients who had ACSI after stent placement in our hospital between January 2015 and July 2020. All patients underwent magnetic resonance imaging with diffusion-weighted imaging (MRI-DWI) after stent placement and 1,485 radiomic features were extracted from each patient. The least absolute shrinkage and selection operator regression methods were used for selection of high-risk radiomic features associated with clinical symptoms. In addition, 199 patients with ASCI were classified into three groups: controls without HPR (n = 113), HPR patients with standard antiplatelet therapy (n = 63) and HPR patients with antiplatelet therapy adjustment (n = 23). We compared high-risk radiomic features between three groups.

Results

Of the patients who had acute infarction after MRI-DWI, 31 (13.5%) exhibited clinical symptoms. Eight risk radiomic features associated with clinical symptoms were selected, and the radiomics signature exhibited good performance. In ASCI patients, compared with controls, the radiomic characteristics of ischemic lesion in HPR patients were consistent with the following high-risk radiomic features associated with clinical symptoms: higher gray-level values, greater variance in intensity values, and greater homogeneity. However, the adjustment of antiplatelet therapy in HPR patients modified the high-risk radiomic features, which showed lower gray-level values, less variance in intensity values, and more heterogeneous texture. The radiomic shape feature of elongation showed no notable difference between three groups.

Conclusion

Adjustment of antiplatelet therapy might reduce the high-risk radiomic features of UIA patients with HPR after stent placement.

Treatment strategy for giant thrombosed aneurysm of the basilar artery with associated obstructive hydrocephalus

Background

There is no established adequate treatment for thrombosed aneurysm of the basilar artery with obstructive hydrocephalus. We conducted coil embolization and peritoneal shunting followed by placement of a stent expected to exert flow diversion (FD) effects to treat 2 patients with giant thrombosed aneurysms of the basilar artery with associated obstructive hydrocephalus, with good results.

Methods

From April 2019 to March 2021, consecutive two cases of symptomatic hydrocephalus due to giant thrombosed aneurysms in the posterior cranial fossa at our hospital were treated. At first, coil embolization was performed to prevent aneurysm rupture. After coil embolization, ventriculoperitoneal shunting was performed. Finally, stent-assisted coil embolization was performed with flow re-direction endoluminal device (FRED) or low-profile visualized intraluminal support device (LVIS) stent.

Results

Both patients were discharged after recovering well, with no postoperative hemorrhagic or ischemic complications.

Conclusion

Staged surgery using a FRED for flow diverter or an LVIS stent expected to have FD effects may offer an effective treatment option.

[Hemostatic disorders in neurosurgical patients: diagnostics and correction]

The authors analyzed the main causes of perioperative hemostatic disorders in neurosurgical patients. The problem of preoperative hemostatic screening, intraoperative and postoperative factors contributing to hemostatic disorders are considered. The authors also discuss the methods for correction of hemostatic disorders.

Factors associated with in-stent stenosis after cerebral aneurysm embolization using a Pipeline embolization device

BACKGROUND

Flow-diverting (FD) stents, with or without coiling, are a mainstay in endovascular treatment of intracranial aneurysms (IAs). One observed complication from flow diverter stent (FDS) insertion has been in-stent stenosis. Though previously studied in the short-term period, the long-term history of this complication has yet to be described.

METHODS

We performed a retrospective cohort study of consecutive IAs treated with Pipeline Embolization Device (PED), with or without coiling, at our centre between September 2014 and December 2018 that had at least one digital subtraction angiogram (DSA) during follow-up. In-stent stenosis was measured from DSA images, and associated patient and procedural characteristics were analysed.

RESULTS

94 patients treated with PED for IA were identified. On initial DSA during follow-up, 52 patients (55.3%) had in-stent stenosis within the PED. Of these 52 patients, 17 had a second DSA during follow-up. In this 2nd DSA, improvement and/or stable in-stent stenosis was seen 16 patients (94.1%). One patient in this group had worsening in-stent stenosis had a vertebrobasilar junction FD stent. Of the patients without in-stent stenosis on initial DSA, 15 had a second DSA during follow-up. Only one of these patients (6.7%) had new appearance of in-stent stenosis (measuring 5%). Multivariate analysis found statin use to be predictive of in-stent stenosis (p = 0.020, Odds ratio = 0.279 and 95% confidence interval = 0.095-0.821).

CONCLUSIONS

In-stent stenosis after FDS placement was seen in 53.2% of cases, which had between 1-50% of stenosis. 82.4% had resolution/improvement of their stenosis. Statin use was protective of in-stent stenosis.

Clopidogrel hyper-response increases peripheral hemorrhagic complications without increasing intracranial complications in endovascular aneurysm treatments requiring dual antiplatelet therapy

Clinical significance of increased clopidogrel response measured by VerifyNow P2Y12 assay is unclear; management guidelines are lacking in the context of neuroendovascular intervention. Our objective was to assess whether increased clopidogrel response predicts complications from endovascular aneurysm treatment requiring dual antiplatelet therapy. A single-institution, 9-year retrospective study of patients undergoing endovascular treatments for ruptured and unruptured aneurysms requiring aspirin and clopidogrel was conducted. Patients were grouped according to preoperative platelet inhibition in response to clopidogrel measured by the VerifyNow P2Y12 assay (VNP; P2Y12 reactivity units, PRU). Demographic and clinical features were compared across groups. Hemorrhagic complication rates (intracranial, major extracranial, minor extracranial) and thromboembolic complications (in-stent stenosis, stroke/transient ischemic attack) were compared, controlling for potential confounders and multiple comparisons. Data were collected from 284 patients across 317 procedures. Pre-operative VNP assays identified 9 % Extreme Responders (PRU ≤ 15), 13 % Hyper-Responders (PRU 16-60), 62 % Therapeutic Responders (PRU 61-214), 16 % Hypo-Responders (PRU ≥ 215). Increased response to clopidogrel was associated with increased risk of any hemorrhagic complication (≤60 PRU vs > 60 PRU; 39 % vs 24 %, P = 0.050); all intracranial hemorrhages occurred in patients with PRU > 60. Thromboembolic complications were similar between therapeutic and subtherapeutic patients (<215 PRU vs ≥ 215 PRU; 15 % vs 16 %, P = 0.835). Increased preoperative clopidogrel response is associated with increased rate of extracranial hemorrhagic complications in endovascular aneurysm treatments. Hyper-responders (16-60 PRU) and Extreme Responders (≤15 PRU) were not associated with intracranial hemorrhagic or thrombotic complications. Hypo-responders who underwent adjustment of antiplatelet therapy and neurointerventions did not experience higher rates of complications.

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.

Internal carotid artery blister aneurysm rupture: a unifying diagnosis for massive epistaxis and unilateral embolic strokes

Concurrent epistaxis, embolic stroke and a ruptured internal carotid artery are rare but life-threatening delayed complications of cured nasopharyngeal squamous cell carcinoma. A timely diagnosis and effective management can be problematic. We report a case that highlights the unique diagnostic features of this presentation and contemporary endovascular treatment options available.

Carotid Artery Stenting in Patients with Atrial Fibrillation: Direct Oral Anticoagulants, Brief Double Antiplatelets, and Testing Strategy

Carotid endarterectomy is usually preferred over carotid artery stenting (CAS) for patients with atrial fibrillation (AF). We present our experience with short-course periprocedural triple antithrombotic therapy in 32 patients aged >18 years with nonvalvular AF undergoing CAS. There were no deaths, cardiac events, embolic strokes, hyperperfusion syndrome, intracranial hemorrhage, or stent thrombosis within 30 days. Transient intraprocedural hemodynamic instability in 15/32 (47%) and prolonged instability in 4/32 (13%) was managed conservatively. At a mean 16-month follow-up, there were no new neurological events or deterioration. Mean stenosis was reduced from 78.0% ± 9.7% to 17.3% ± 12.2%. This retrospective study included patients AF who were symptomatic (minor stroke (NIHSS ≤ 5)/TIA) with ICA stenosis >50%, or asymptomatic under DOAC therapy with carotid stenosis >80%, who underwent CAS from 6/2014-10/2020. Patients received double antiplatelets and statins. Antiplatelet therapy effectiveness was monitored. Stenting was performed when P2Y12 reaction units (PRU) were <150. DOACs were discontinued 48 h before angioplasty; one 60 mg dose of subcutaneous enoxaparin was administered in lieu. DOAC was restarted 12-24 h after intervention. Patients were discharged under DOAC and one nonaspirin antiplatelet. 32 patients on DOAC were included (26 male, mean age 71). 19 (59.4%) presented with stroke (ICA stenosis-related in 14); 13 (40.6%) were asymptomatic. Stents were deployed under filter protection following pre-angioplasty; post-angioplasty was performed at least once in 12 patients (37.5%). Our experience suggests that CAS can be safely performed in selected patients with CAS and AF requiring DOAC. The role of CAS in AF patients under DOAC warrants study in rigorous trials.

Effect of Adjusted Antiplatelet Therapy on Preventing Ischemic Events After Stenting for Intracranial Aneurysms

BACKGROUND AND PURPOSE

This study tests whether patients with unruptured intracranial aneurysm who underwent stent placement benefitted from platelet function monitoring-guided adjustment of antiplatelet therapy.

METHODS

We conducted a randomized, open-label, parallel group, assessor-blinded trial. Patients with unruptured intracranial aneurysm who underwent stent placement were assigned in a 1:1 ratio to receive either drug adjustment (patients who had high on-treatment platelet reactivity to antiplatelet therapy on the basis of platelet function monitoring [monitoring group]) or conventional therapy (without monitoring and drug adjustment [conventional group]). The second monitoring was performed 14 days after randomization in patients with drug adjustment. The primary outcome was the composite frequency of ischemic stroke, transient ischemic attack, stent thrombosis, urgent revascularization, and cerebrovascular death within 7 days after stent implantation. The safety outcome was the composite frequency of major, minor, or minimal bleeding within 1 month after stent implantation.

RESULTS

In total, 314 patients were included (n=157 per group). The primary combined outcome occurred in 19 patients (12.1%) in the conventional group and 8 patients (5.1%) in the monitoring group (hazard ratio, 0.39 [95% CI, 0.17-0.92]; P=0.03). Ischemic stroke occurred at a lower frequency in the monitoring group compared with that in the conventional group (4.5% versus 12.1%; hazard ratio, 0.34 [95% CI, 0.14-0.83]; P=0.01), which drove the overall primary combined outcome. The safety outcome occurred in the monitoring group (7.0%) and in the conventional group (1.9%; hazard ratio, 3.87 [95% CI, 1.06-14.14]; P=0.03). A significant difference was observed in the frequency of minor or minimal bleeding events between the two groups (monitoring group versus conventional group, 6.4% versus 1.3%; P=0.02) but not in the frequency of major bleeding events between the two groups.

CONCLUSIONS

Platelet function monitoring-guided antiplatelet therapy reduces thromboembolic events in patients with unruptured intracranial aneurysm after stent placement, significantly enhancing minor or minimal bleeding events but not major bleeding events. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03989557.

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.

Safety and Efficacy of Stent-Assisted Coiling of Unruptured Intracranial Aneurysms Using Low-Profile Stents in Small Parent Arteries

BACKGROUND AND PURPOSE

Stent-assisted coiling of intracranial aneurysms arising from small vessels (≤ 2.0 mm) is a common procedure. However, data regarding its treatment outcomes are scarce. This study evaluated the clinical and radiologic outcomes of stent-assisted coiling using low-profile stents for aneurysms of small parent arteries.

MATERIALS AND METHODS

From November 2015 to October 2020, sixty-four patients with 66 aneurysms arising from parent arteries of ≤2.0 mm were treated with stent-assisted coiling using a Low-Profile Visualized Intraluminal Support Junior (LVIS Jr) or the Neuroform Atlas stent in a single institution. The clinical and radiologic data were retrospectively reviewed, and the risk factors for procedure-related complications were evaluated.

RESULTS

The LVIS Jr and Neuroform Atlas stents were used in 22 (33.3%) and 44 (66.7%) cases, respectively. Technical success was achieved in 66 cases (100%). Immediate postprocedural aneurysm occlusion grades assessed by the Raymond-Roy occlusion classification were I (57.6%), II (19.7%), and III (22.7%), respectively. Procedure-related complications occurred in 10 cases (15.2%), with 8 thromboembolic complications (12.1%) and 2 hemorrhagic complications (3.0%). Procedure-related morbidity was 4.5% without mortality. On multivariate analysis, current smoking (odds ratio = 7.1, P = .021) had a statistically significant effect on procedure-related complications.

CONCLUSIONS

Stent-assisted coiling of intracranial aneurysms with low-profile stents in small vessels (≤ 2.0 mm) had a 100% success rate and a 15.2% overall complication rate with 4.5% morbidity. Current smoking was a significant risk factor associated with procedure-related complications.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Intracranial Stenting or Flow-Diverter Treatment for Unruptured Cerebral Aneurysms: A Single-Center Cohort Study

BACKGROUND AND PURPOSE

Ticagrelor is a novel P2Y12 antagonist, and little is known about its efficacy and safety in the endovascular treatment of aneurysms. This study evaluated the efficacy and safety of ticagrelor versus clopidogrel for stent-assisted coiling or flow-diversion treatment in patients with unruptured cerebral aneurysms.

MATERIALS AND METHODS

From November 2003 to February 2019, two hundred one patients (mean age, 57.5 years; 156 women) with 233 unruptured aneurysms underwent stent-assisted coiling or flow-diversion treatment. All patients received antiplatelet therapy of aspirin plus clopidogrel (clopidogrel group, 121 patients with 140 aneurysms) or aspirin plus ticagrelor (ticagrelor group, 80 patients with 93 aneurysms). The clinical and radiologic data in each group were retrospectively reviewed and compared.

RESULTS

Two hundred thirty-six procedures were performed, including stent-assisted coiling (n = 101) and flow diversion (n = 135). At 90 days, the primary outcome-a composite of any stroke and death-occurred in 9.9% of the clopidogrel group and 8.6% of the ticagrelor group (P = .822). Ischemic stroke occurred in 10 (7.0%) of the clopidogrel group and 7 (7.5%) of the ticagrelor group (P > .999). Disabling stroke occurred in 4 (2.8%) in the clopidogrel group and in 4 (4.3%) in the ticagrelor group (P = .716). Ninety-day death occurred in 3 (2.1%) in the clopidogrel group and 1 (1.1%) in the ticagrelor group (P > .999). Any bleeding at 90 days occurred in 13 (9.2%) in the clopidogrel group and 6 (6.5%) in the ticagrelor group (P = .479).

CONCLUSIONS

Ticagrelor appears to be as effective and safe as clopidogrel in stent-assisted coiling or flow-diversion treatment for unruptured cerebral aneurysms.

Self-expanding covered stent placement to treat a pseudoaneurysm caused by iatrogenic vertebral artery injury

Vertebral artery injuries account for approximately 19% of cerebral vascular injuries and are typically managed conservatively. However, some patients require operative intervention to gain control of an active hemorrhage, either via surgical ligation or endovascular intervention. We present a case of iatrogenic vertebral artery injury occurring during cervical spine surgery which was treated emergently with a self-expanding covered stent. A 58-year-old male presented for cervical traction, C5 and C6 corpectomy, and possible C4 to T2 posterior fusion following a motor vehicle accident. Intraoperatively, following drilling the C5 endplate, copious bleeding was observed from injury to the right vertebral artery resulting in pseudoaneurysm formation. The patient was loaded with ticagrelor and a self-expanding covered stent was placed via a transfemoral approach, resulting in obliteration of the pseudoaneurysm prior to completion of his cervical spine surgery. Emergent self-expanding covered stent placement for iatrogenic vertebral artery injury in the setting of an intraoperative injury is a safe and effective option. Ticagrelor is a viable alternative to traditional dual antiplatelet therapy for preventing thromboembolic complications in this urgent setting.

The Safety of Intra-arterial Tirofiban during Endovascular Therapy after Intravenous Thrombolysis

BACKGROUND AND PURPOSE

The safety and efficacy of tirofiban during endovascular therapy in patients undergoing intravenous thrombolysis with recombinant IV tPA remain unclear. This study aimed to investigate the safety and efficacy of intra-arterial tirofiban use during endovascular therapy in patients treated with IV tPA.

MATERIALS AND METHODS

Using a multicenter registry, we enrolled patients with acute ischemic stroke who underwent endovascular therapy. Safety outcomes included postprocedural parenchymal hematoma type 2 and/or thick subarachnoid hemorrhage, intraventricular hemorrhage, and 3-month mortality. Efficacy outcomes included the successful reperfusion rate, postprocedural reocclusion, and good outcomes at 3 months (mRS scores of 0-2). The tirofiban effect on the outcomes was evaluated using a multivariable analysis while adjusting for potential confounders.

RESULTS

Among enrolled patients, we identified 314 patients with stroke (279 and 35 patients in the no tirofiban and tirofiban groups, respectively) due to an intracranial artery occlusion who underwent endovascular therapy with intravenous thrombolysis. A multivariable analysis revealed no association of intra-arterial tirofiban with postprocedural parenchymal hematoma type and/or thick subarachnoid hemorrhage (adjusted OR, 1.07; 95% CI, 0.20-4.10; P = .918), intraventricular hemorrhage (adjusted OR, 0.43; 95% CI, 0.02-2.85; P = .467), and 3-month mortality (adjusted OR, 0.38; 95% CI, 0.04-1.87; P = .299). Intra-arterial tirofiban was not associated with good outcome (adjusted OR, 2.22; 95% CI, 0.89 -6.12; P = .099).

CONCLUSIONS

Using intra-arterial tirofiban during endovascular therapy after IV tPA could be safe.

Ticagrelor resistance: a case series and algorithm for management of non-responders

The placement of cervical and intracranial stents requires the administration of antiplatelet drugs to prevent thromboembolic complications. Ticagrelor has emerged as the most widely used alternative in clopidogrel non-responders owing to its potent antiplatelet effects. Because ticagrelor does not require hepatic activation, many neurointerventionalists choose to forgo laboratory testing of platelet inhibition. In rare instances, patients may not achieve adequate platelet inhibition following ticagrelor administration. In this paper we review the mechanism of action of ticagrelor and its use in cerebrovascular procedures. We present two cases of ticagrelor non-responsiveness from two high-volume cerebrovascular centers, discuss their management, and propose an algorithm for managing ticagrelor non-responsiveness.

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.

P2Y12 inhibitors for the neurointerventionalist

The use of antiplatelets is widespread in clinical practice. However, for neurointerventional procedures, protocols for antiplatelet use are scarce and practice varies between individuals and institutions. This is further complicated by the quantity of antiplatelet agents which differ in route of administration, dosage, onset of action, efficacy and ischemic and hemorrhagic complications. Clarifying the individual characteristics for each antiplatelet agent, and their associated risks, will increasingly become relevant as the practice of mechanical thrombectomy, stenting, coiling and flow diversion procedures grows. The aim of this review is to summarize the existing literature for the use of P2Y12 inhibitors in neurointerventional procedures, examine the quality of the evidence, and highlight areas in need of further research.

Intravenous Tirofiban Infusion After Angioplasty and Stenting in Intracranial Atherosclerotic Stenosis-Related Stroke

[Figure: see text].

Early experience with a novel net temporary bridging device (Cascade) to assist endovascular coil embolization of intracranial aneurysms

OBJECTIVE

The goal of this study was to evaluate the effectiveness and safety of a new noncompletely occlusive net-assisted remodeling technique in which the Cascade net device is used for temporary bridging of intracranial aneurysms.

METHODS

Between July 2018 and May 2019, patients underwent coil embolization with the Cascade net device within 4 centers in Europe. Analysis of angiographic (modified Raymond-Roy classification [MRRC]) and clinical outcomes data was conducted immediately following treatment and at the 6-month follow-up.

RESULTS

Fifteen patients were included in the study (mean age 58 ± 13 years, 11/15 [73.3%] female). Ten patients had unruptured aneurysms, and 5 presented with ruptured aneurysms with acute subarachnoid hemorrhage. The mean aneurysm dome length was 6.27 ± 2.33 mm and the mean neck width was 3.64 ± 1.19 mm. Immediately postprocedure, MRRC type I (complete obliteration) was achieved in 11 patients (73.3%), whereas a type II (residual neck) was achieved in 4 patients (26.7%). Follow-up examination was performed in 7/15 patients and showed stabilization of aneurysm closure with no thromboembolic complications and only 1 patient with an increased MRRC score (from I to II) due to coil compression.

CONCLUSIONS

Initial experience shows that the use of a new noncompletely occlusive net-assisted remodeling technique with the Cascade net device may be safe and effective for endovascular coil embolization of intracranial aneurysms.

Periprocedural Variability of Platelet Functions in Carotid Artery Stenting: An Analysis Using VerifyNow

Objective

The assessment of platelet functions is necessary to prevent both thromboembolic and hemorrhagic complications under dual antiplatelet therapy (DAPT). Using the VerifyNow (Accumetrics, Inc., San Diego, CA, USA) assay, this study aimed to reveal time-dependent changes in platelet functions after carotid artery stenting (CAS).

Methods

We enrolled retrospectively 43 patients who underwent CAS under DAPT. Aspirin reaction unit (ARU) and P2Y12 reaction unit (PRU) values were determined on the day before and on days 1, 3, and 7 after the procedure. Multiple comparison tests (MCTs) were performed among ARU and PRU measurement points, and the proportions of hypo- and hyper-responses were compared.

Results

The median ARU values were 408 (interquartile range: 392-497) before CAS and 418 (405-470) on day 1, 405 (393.0-460.5) on day 3, and 402 (388.5-477.5) on day 7 (not significant in MCTs). The percentages of hypo-responses were 16.3%, 7.0%, 2.3%, and 7.0%, respectively (p = 0.11). The significantly different median PRU values were 173 (116.5-209.5), 233 (166.5-273.5), 139 (70.5-205.5), and 51 (9.0-79.5), respectively. The median PRU was before the procedure within the therapeutic range but exceeded the upper cutoff on day 1 and was below the lower cutoff on day 7. The percentages of hypo-responses were 14.0%, 51.2%, 18.6%, and 11.6%, respectively (p <0.001) and the percentages of hyper-responses were 9.3%, 2.3%, 23.3%, and 62.8%, respectively (p <0.001).

Conclusion

In the periprocedural CAS period, ARU values were stable, but PRU values showed time-dependent changes. PRU values were above the therapeutic range the day after CAS but decreased below this range on day 7.