Impact of duration of dual anti-platelet therapy on risk of complications after stent-assisted coiling of unruptured aneurysms

BACKGROUND

The optimal duration for dual antiplatelet therapy (DAPT) after stent-assisted coiling (SAC) of intracranial aneurysms is unclear. Longer-term therapy may reduce thrombotic complications but increase the risk of bleeding complications.

METHODS

A retrospective review of prospectively maintained data at 12 institutions was conducted on patients with unruptured intracranial aneurysms who underwent SAC between January 1, 2016 and December 31, 2020, and were followed ≥6 months postprocedure. The type and duration of DAPT, stent(s) used, outcome, length of follow-up, complication rates, and incidence of significant in-stent stenosis (ISS) were collected.

RESULTS

Of 556 patients reviewed, 450 met all inclusion criteria. Nine patients treated with DAPT <29 days after SAC and 11 treated for 43-89 days were excluded from the final analysis as none completed their prescribed duration of treatment. Eighty patients received short-term DAPT. There were no significant differences in the rate of thrombotic complications during predefined periods of risk in the short, medium, or long-term treatment groups (1/80, 1.3%; 2/188, 1.1%; and 0/162, 0%, respectively). Similarly, no differences were found in the rate of hemorrhagic complications during period of risk in any group (0/80, 0%; 3/188, 1.6%; and 1/162, 0.6%, respectively). Longer duration DAPT did not reduce ISS risk in any group.

CONCLUSIONS

Continuing DAPT >42 days after SAC did not reduce the risk of thrombotic complications or in-stent stenosis, although the risk of additional hemorrhagic complications remained low. It may be reasonable to discontinue DAPT after 42 days following non-flow diverting SAC of unruptured intracranial aneurysms.

Risk Factors, Antithrombotic Management, and Long-Term Outcomes of Patients Undergoing Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND

 Patients receiving endovascular treatment for unruptured intracranial aneurysms (UIAs) face varying risks and benefits with antithrombotic management. This study aimed to evaluate the perioperative and long-term effects of antithrombotic strategies, identify the populations that would benefit, and explore the predictive factors affecting the long-term outcomes.

METHODS

 UIA patients undergoing endovascular treatment including stent-assisted coiling or flow diversion between June 2019 and June 2022 were enrolled. We compared perioperative and long-term complications between tirofiban and dual antiplatelet therapy groups. Optimal candidates for each antithrombotic treatment were identified using multivariate logistic regression. Nomograms were developed to determine the significant predictors for thromboembolic complications during follow-up.

RESULTS

 Among 181 propensity-score matched pairs, the tirofiban group showed a trend toward a lower rate of thromboembolic complications than the DAPT group without elevating major bleeding risk in either period. Homocysteine (Hcy) level ≥10 μmol/L was a significant independent factor associated with thromboembolic complication in both periods. Subgroup analysis highlighted that in patients with high Hcy levels, tirofiban and sustained antiplatelet treatment for ≥12 months were protective factors, while a history of stroke was an independent risk factor for thromboembolic events in follow-up. Four variables were selected to construct a prognostic nomogram, history of hypertension, prior stroke, Hcy level, and the duration of antiplatelet therapy.

CONCLUSION

 Perioperative low-dose tirofiban and extended antiplatelet therapy demonstrated a favorable trend in long-term outcomes for UIA patients with preoperative Hcy levels ≥10 μmol/L undergoing endovascular treatment. The prognostic model offers reliable risk prediction and guides antithrombotic strategy decisions.

The Usefulness of Extradural Anterior Clinoidectomy for Lower-Lying Posterior Communicating Artery Aneurysms : A Cadaveric Study

OBJECTIVE

To confirm the usefulness of the extradural anterior clinoidectomy during the clipping of a lower riding posterior communicating artery (PCoA) aneurysm through cadaver dissection.

METHODS

Anatomic measurements of 12 adult cadaveric heads (24 sides total) were performed to compare the microsurgical exposure of the PCoA and internal carotid artery (ICA) before and after clinoidectomy. A standard pterional craniotomy and transsylvian approach were performed in all cadavers. The distance from the ICA bifurcation to the origin of PCoA (D1), pre-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D2), post-anterior clinoidectomy distance from the ICA bifurcation to tentorium (D3), pre-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D4) and post-anterior clinoidectomy distance from the tentorium to the origin of PCoA (D5) and the distance of the ICA obtained after anterior clinoidectomy (D6) were measured. We measured the precise thickness of the blade for the Yasargil clip with a digital precision ruler to confirm the usefulness of the extradural anterior clinoidectomy.

RESULTS

Twenty-four sites were dissected from 12 cadavers. The age of the cadavers was 79.83±6.25 years. The number of males was the same as the females. The space from the proximal origin of the PCoA to the preclinoid-tentorium (D4) was 1.45±1.08 mm (max, 4.01; min, 0.56). After the clinoidectomy, the space from the proximal origin of the PCoA to the postclinoid-tentorium (D5) was 3.612±1.15 mm (max, 6.14; min, 1.83). The length (D6) of the exposed proximal ICA after the extradural clinoididectomy was 2.17±1.04 mm on the lateral side and 2.16±0.89 mm on the medial side. The thickness of the Yasargil clip blade used during the clipping surgery was 1.35 mm measured with a digital precision ruler.

CONCLUSION

The proximal length obtained by performing an external anterior clinoidectomy is about 2 mm, sufficient for proximal control during PCoA aneurysm surgery, considering the thickness of the aneurysm clips. In a subarachnoid hemorrhage, performing an extradural anterior clinoidectomy could prevent a devastating situation during PCoA aneurysm clipping.

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.

Short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE): a multicenter, open-label, randomized clinical trial

BACKGROUND

The optimal duration of dual antiplatelet therapy (DAPT) after stent-assisted coil embolization (SACE) for cerebral aneurysm remains uncertain. This randomized trial of short- versus long-term Dual AntiPlatelet Therapy for Stent-Assisted treatment of CErebral aneurysm (DAPTS ACE) aimed to clarify whether long-term DAPT can reduce the occurrence of ischemic stroke in patients with cerebral aneurysms treated by SACE compared with short-term DAPT.

METHODS

Patients treated for cerebral aneurysm with SACE were enrolled from 17 hospitals in Japan. Patients were enrolled within 30 days after SACE and assigned in a 1:1 ratio to receive long-term (12 months) or short-term (3 months) DAPT with aspirin and clopidogrel. Randomization was performed centrally through a web-based system. The primary outcome was the time to ischemic stroke event during 3 to 12 months after SACE. This trial was registered with the Japan Registry of Clinical Trials (jRCTs051180141).

RESULTS

A total of 142 patients were recruited from November 4, 2016 to January 7, 2019. Among them, 65 and 68 patients assigned to the long- and short-term DAPT groups, respectively, were included in the full analysis set. Ischemic stroke occurred in no patients in the long-term DAPT group and in one patient in the short-term DAPT group. The incidence rate did not differ between the groups (0.0 vs 2.1/100 person-years; log rank test, P=0.33).

CONCLUSIONS

In this multicenter randomized controlled trial, there was not a statistically significant difference in the rate of ischemic strokes between long- and short-term DAPT.

Safety of dual antiplatelet therapy using aspirin and low-dose Prasugrel with platelet reactivity testing in flow diverter treatment of intracranial aneurysms

BACKGROUND

Dual antiplatelet therapy (DAPT) is standard care for intracranial stenting to prevent thrombotic complications. Clopidogrel resistance has resulted in patients receiving newer P2Y12 inhibitors like Prasugrel, which may reduce thrombotic complications but could increase haemorrhagic complications. This study, utilising platelet reactivity testing, compared thrombotic and haemorrhagic complications associated with Clopidogrel or 20 mg Prasugrel loading in patients treated with flow diverters (FD) for intracranial aneurysms.

METHODS

We retrospectively analysed prospectively collected data from 225 consecutive FD procedures. All patients received aspirin. 147 cases received Clopidogrel and 82 received Prasugrel. All patients had VerifyNow testing before the procedure.

RESULTS

P2Y12 non-responders were significantly more likely to have thrombotic complications than responders and hyper-responders (7% vs. 2%, p = 0.01). Low-dose Prasugrel resulted in a significantly lower rate of non-responders when compared with Clopidogrel (7% vs. 25%, p < 0.01). We found no statistically significant difference in rates of haemorrhage between the Clopidogrel and Prasugrel groups (2.4% vs. 3.9%, p = 0.47). There were 12 complications (≤7 days) in the Clopidogrel group versus 6 in the Prasugrel group (9% vs. 7.8%, respectively, p = 0.91) and a non-significant reduction in thrombotic complications in the Prasugrel group (5.2% vs. 3.9%, p = 0.88). No significant difference was shown in long-term complications between the groups (p = 0.33).

CONCLUSION

These results support the use of platelet reactivity testing and the safety of low-dose Prasugrel for FD treatment of intracranial aneurysms.

Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms: a nationwide registry study

BACKGROUND

Antiplatelet therapy, where regimens are tailored based on platelet function testing, has been introduced into neurointerventional surgery. This nationwide registry study evaluated the effect and safety of tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms compared with conventional therapy using a standard regimen.

METHODS

This study enrolled 1686 patients in 44 participating centers who received stent assisted coiling for unruptured aneurysms between January 1, 2019 and December 31, 2019. The standard regimen (aspirin and clopidogrel) was used for all patients in the conventional group (924, 19 centers). The regimen was selected based on platelet function testing (standard regimen for clopidogrel responders; adding cilostazol or replacing clopidogrel with other thienopyridines (ticlopidine, prasugrel, or ticagrelor) for clopidogrel non-responders) in the tailored group (762, 25 centers). The primary outcome was thromboembolic events. Secondary outcomes were bleeding and poor outcomes (increase in modified Rankin Scale score). Outcomes within 30 days after coiling were compared using logistic regression analysis.

RESULTS

The thromboembolic event rate was lower in the tailored group than in the conventional group (30/762 (3.9%) vs 63/924 (6.8%), adjusted OR 0.560, 95% CI 0.359 to 0.875, P=0.001). The bleeding event rate was not different between the study groups (62/762 (8.1%) vs 73/924 (7.9%), adjusted OR 0.790, 95% CI 0.469 to 1.331, P=0.376). Poor outcomes were less frequent in the tailored group (12/762 (1.6%) vs 34 (3.7%), adjusted OR 0.252, 95% CI 0.112 to 0.568, P=0.001).

CONCLUSION

Tailored antiplatelet therapy in stent assisted coiling for unruptured aneurysms reduced thromboembolic events and poor outcomes without increasing bleeding.

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.

Thromboembolic complications during and after embolization of unruptured aneurysms: A chronological outcome in periprocedural thromboembolic events

Background

Ischemic complications develop after elective coil embolization procedures at a certain rate. The prevention of these events has been a longstanding issue for many interventional neuroradiologists. This study aimed to clarify whether procedural ischemic events after unruptured aneurysm embolization decrease over time with perioperative anti-thromboembolic treatment or surgical experience.

Methods

This study included patients with cerebral aneurysms in our institution between July 2012 and June 2020. Dual-antiplatelet therapy (DAPT) was performed (Phase 1). Thromboembolic events developed at a certain rate; thus, rivaroxaban was administered with single-antiplatelet therapy (SAPT) to improve thromboembolic results (Phase 2), showing better outcomes than in Phase 1. Subsequently, DAPT was administered again (Phase 3). Ischemic complications were evaluated in each phase or compared between the DAPT group and the direct oral anticoagulant (DOAC) with the clopidogrel (DOAC+SAPT) group.

Results

Relatively, fewer symptomatic ischemic events were noted in Phase 2 or the DOAC+SAPT group, but the outcome was not better in Phase 3 than in Phase 2. Symptomatic complications were more common in Phase 3 than in Phases 1 and 2.

Conclusion

Ischemic complications occurred at a certain rate after endovascular procedures for unruptured aneurysms. The incidence did not decrease over time; particularly, standard DAPT plus postoperative anti-thromboembolic medication did not adequately decrease complications in Phase 3 compared to Phases 1 and 2. Therefore, accumulated experience or a learning curve could not explain the results. DOAC administration might decrease the risk of these events, but further accumulation of evidence or prospective investigation is warranted.

Risk Factors for Postoperative Puncture Site Bleeding after Interventional Treatment of Cerebrovascular Disease via Common Femoral Artery Puncture: A Retrospective Analysis of 710 Cases

This study aimed to identify the risk factors associated with puncture site bleeding following percutaneous puncture of the common femoral artery during interventional treatment of cerebrovascular disease (CVD). A retrospective analysis was conducted on 710 patients who underwent interventional treatment for CVD via femoral artery puncture. Among them, 26 individuals (3.66%) experienced bleeding at the femoral artery puncture site. Binary logistic regression analysis was performed to identify risk factors for puncture site bleeding. The impact of salt bag compression on postoperative bleeding was evaluated in patients with intermediate to high bleeding risk scores. The bleeding group showed higher blood pressure, lower platelet counts, longer prothrombin time and activated partial thromboplastin time, as well as a higher prevalence of larger vascular sheath sizes and variations in the timing of anti-coagulant and anti-platelet therapy administration. The bleeding risk score was higher in the bleeding group, indicating its predictive value for bleeding risk. Higher bleeding risk score, unstable blood pressure, repeated puncture, and serious vascular conditions were significant risk factors for puncture site bleeding. Application of salt bag compression for a duration of 2 hours reduced postoperative puncture site bleeding in patients with intermediate to high bleeding risk scores. Our study identified several significant risk factors for puncture site bleeding after cerebral vascular intervention via femoral artery puncture, including the bleeding risk score, blood pressure, repeated puncture, and vascular conditions. Implementing salt bag compression as a preventive measure can help mitigate bleeding complications in these high-risk patients.

Trends in the Age of Patients Treated for Unruptured Intracranial Aneurysms from 1990 to 2020

BACKGROUND

The decision for treatment for unruptured intracranial aneurysms (UIAs) is often difficult. Innovation in endovascular devices have improved the benefit-to-risk profile especially for elderly patients; however, the treatment guidelines from the past decade often recommend conservative management. It is unknown how these changes have affected the overall age of the patients selected for treatment. Herein, we aimed to study potential changes in the average age of the patients that are being treated over time.

METHODS

A systematic search of the literature was performed to identify all studies describing the age of the UIAs that were treated by any modality. Scatter diagrams with trend lines were used to plot the age of the patients treated over time and assess the presence of a potential significant trend via statistical correlation tests.

RESULTS

A total of 280 studies including 83,437 UIAs treated between 1987 and 2021 met all eligibility criteria and were entered in the analysis. Mean age of the patients was 55.5 years, and 70.7% were female. There was a significant increasing trend in the age of the treated patients over time (Spearman r: 0.250; P < 0.001), with a 1-year increase in the average age of the treated patients every 5 years since 1987.

CONCLUSIONS

The present study indicates that based on the treated UIA patient data published in the literature, older UIAs are being treated over time. This trend is likely driven by safer treatments while suggesting that re-evaluation of certain UIA treatment decision scores may be of great interest.

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.

Genotype-guided dual antiplatelet therapy in cerebrovascular disease: assessing the risk and benefits for ethnic populations

INTRODUCTION

Cerebrovascular disease is a leading cause of morbidity and mortality in the world and antiplatelet therapy is a main pharmacologic means of secondary prevention. Clinical information has accumulated about benefit of dual antiplatelet therapy in certain clinical scenarios, genetic causes of antiplatelet resistance and its effect on clinical outcomes, and ethnic and geographic distributions of genetic polymorphisms.

AREAS COVERED

This review covers literature related to the pharmacogenomics of antiplatelet agents with a focus on ethnic variability, antiplatelet resistance, and dual antiplatelet therapy in cerebrovascular disease.

EXPERT OPINION

Selecting patients for dual antiplatelet therapy and specific agents require consideration of multiple factors. Ethnic factors should be considered in certain circumstances, but additional research is needed to determine the generalizability of the findings.

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.

Enterprise stents versus low-profile visualized intraluminal support stents for stent-assisted coiling of unruptured paraclinoid aneurysms

BACKGROUND

The microsurgical treatment of paraclinoid aneurysms can be challenging due to the anatomical structures that surround them.

OBJECTIVE

This study compared the clinical and angiographic outcomes of unruptured paraclinoid aneurysms treated with enterprise (EP) stents and low-profile visualized intraluminal support (LVIS) stents.

METHODS

A retrospective analysis of the clinical and radiological data from 133 patients with 139 unruptured paraclinoid aneurysms, who received an EP or an LVIS stent between January 2017 and June 2021 at Taizhou People's Hospital, was performed. Immediate postoperative and follow-up angiographic results were analyzed retrospectively using the Raymond-Roy occlusion classification (RROC). Any complications following the procedure and the patients' clinical outcomes were noted.

RESULTS

Enterprise stents were used for stent-assisted coiling in 64 patients with 68 aneurysms and LVIS stents were used in 69 patients with 71 aneurysms. Both groups exhibited an increase in the proportion of aneurysms meeting the criteria for RROC class I, but the LVIS group demonstrated a higher rate of aneurysms meeting the class I criteria compared with the EP group, both on immediate postoperative angiography (45.1% vs. 11.8%, p< 0.001) and on follow-up angiography (94.9% vs. 80.6%, p= 0.025). Procedure-related complications were experienced by 9.4% of patients in the EP group (one coil prolapse, two parent artery occlusions, and three thromboembolic events), and 8.7% of patients in the LVIS group (three stent-related thrombosis and three thromboembolic events). There were no statistically significant differences between the two groups in relation to perioperative complications (p= 0.746) or favorable clinical outcomes (p= 0.492).

CONCLUSION

A greater proportion of aneurysms in the LVIS group met the criteria for RROC class I compared with the EP group. There is no significant difference in procedural complications or clinical outcomes between EP and LVIS stents. Although no aneurysm recurrence was observed during the short follow-up period, continued monitoring is required.

Primary coiling of a wide-neck unruptured aneurysm in the trifurcation of the P2 segment of the posterior cerebral artery: A case report

Intracranial aneurysms are now treatable with coils, stents, and flow diverters in recent years. For saccular aneurysms with broad necks and short domes, stent-assisted coiling has become a common technique, but over time, the complications—both intraprocedural and in a delayed fashion—occur more frequently than coiling alone. Nonstent or balloon-assisted coiling results in lower aneurysm recanalization, lower aneurysm rupture or re-rupture, or lower aneurysm retreatment. This paper illustrates a successful coiling of wide-neck unruptured aneurysm in the trifurcation of the left P2 posterior cerebral artery done without the assistance of stents or balloons.

Coil Embolization of Unruptured Cerebral Aneurysms Using Stents in Small Arteries Less Than 2 mm in Diameter

BACKGROUND

Data regarding the safety and effectiveness of stent placement in small vessels (<2 mm in diameter) for treating wide-necked cerebral aneurysms are limited.

OBJECTIVE

To report our experience regarding coil embolization of unruptured cerebral aneurysms using stents (specifically the Neuroform Atlas) in small arteries <2 mm in diameter.

METHODS

Patients with unruptured cerebral aneurysms treated with stent-assisted coil embolization between March 2017 and March 2021 in our hospital were included.

RESULTS

Of the 137 cerebral aneurysms included in this study, 49 required stent placement and 48 were treated using the Neuroform Atlas in the small vessels measuring <2 mm in diameter (small vessel group [SVG]). In the SVG, 43 aneurysms (87.8%) demonstrated complete occlusion. Regarding complications, 2 (4.1%) patients had in-stent thrombosis during procedures and 5 (10.2%) experienced symptomatic thromboembolic complications, but only 2 (4.1%) had worsening of the modified Rankin scale ≥1 at 90 days after embolization. Patients with middle cerebral artery aneurysms had a higher risk of thrombotic events (5/18 patients, 27.8%), such as symptomatic thromboembolic complications or intraprocedural in-stent thrombus than those with other aneurysms (1/31 patients, 3.2%), in the SVG (P = .0167).

CONCLUSION

Stent-assisted coil embolization for unruptured cerebral aneurysms using stents, especially the Neuroform Atlas, in small arteries <2 mm in diameter is effective and feasible, but careful perioperative attention should be given to thrombotic events during the embolization of middle cerebral artery aneurysms.

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.

The inhibition rate estimated using VerifyNow can help to predict the thromboembolic risk of coil embolization for unruptured intracranial aneurysms

BACKGROUND

The role of the inhibition rate of VerifyNow in assessing the thromboembolic risk of coil embolization for unruptured intracranial aneurysms is unclear.

OBJECTIVE

To carry out a retrospective study to determine whether the inhibition rate could provide additional help in predicting thromboembolic events when it was used for patients with a P2Y12 reaction unit (PRU) level of 220 or lower.

METHODS

Patients who underwent coil embolization for unruptured aneurysms with an appropriate PRU level (PRU 220 or lower) between January 1, 2015 and December 31, 2018 were analyzed. A total of 954 patients with 1020 aneurysms were included in this study. The primary outcome was the thromboembolic events occurring within 30 days after coil embolization. The receiver operating characteristic (ROC) curve and the area under the curve (AUC) were obtained to determine the quantitative predictive ability of the inhibition rate. The optimal cut-off value was derived using the Youden index.

RESULTS

Thromboembolic events developed in 11 patients (1.08% of 1020 procedures). The AUC of the ROC curve was 0.83. The optimal cut-off value of the inhibition rate derived using the maximum Youden index was 22.0%. A sensitivity test using a multiple logistic regression analysis demonstrated that the inhibition rate was a significant variable for predicting thromboembolic events.

CONCLUSIONS

The inhibition rate can be used to determine high thromboembolic risks for patients with PRU levels of 220 or lower. The optimal cut-off value of the inhibition rate was 22.0% when the PRU level was 220 or less.

Risk Factors for Recanalization after Coil Embolization

The aim of our study was to identify risk factors for recanalization 6 months after coil embolization using clinical data followed by computational fluid dynamics (CFD) analysis. Methods: Firstly, clinical data of 184 patients treated with coil embolization were analyzed retrospectively. Secondly, aneurysm models for high/low recanalization risk were generated based on ROC curves and their cut-off points. Afterward, CFD was utilized to validate the results. Results: In multivariable analysis, aneurysm filling during the first embolization was an independent risk factor whilst packing density was a protective factor of recanalization after 6 months in patients with aSAH. For patients with unruptured aneurysms, packing density was found to be a protective factor whilst the aneurysm neck size was an independent risk factor. Complex flow pattern and multiple vortices were associated with aneurysm shape and were characteristic of the high recanalization risk group. Conclusions: Statistical analysis suggested that there are various factors influencing recanalization risk. Once certain values of morphometric parameters are exceeded, a complex flow with numerous vortices occurs. This phenomenon was revealed due to CFD investigations that validated our statistical research. Thus, the complex flow pattern itself can be treated as a relevant recanalization predictor.

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.

Clopidogrel response predicts thromboembolic events associated with coil embolization of unruptured intracranial aneurysms: A prospective cohort study

Objective

Periprocedural thromboembolic events are a serious complication associated with coil embolization of unruptured intracranial aneurysms. However, no established clinical rule for predicting thromboembolic events exists. This study aimed to clarify the significance of adding preoperative clopidogrel response value to clinical factors when predicting the occurrence of thromboembolic events during/after coil embolization and to develop a nomogram for thromboembolic event prediction.

Methods

In this prospective, single-center, cohort study, we included 345 patients undergoing elective coil embolization for unruptured intracranial aneurysm. Thromboembolic event was defined as the occurrence of intra-procedural thrombus formation and postprocedural symptomatic cerebral infarction within 7 days. We evaluated preoperative clopidogrel response and patients’ clinical information. We developed a patient-clinical-information model for thromboembolic event using multivariate analysis and compared its efficiency with that of patient-clinical-information plus preoperative clopidogrel response model. The predictive performances of the two models were assessed using area under the receiver-operating characteristic curve (AUC-ROC) with bootstrap method and compared using net reclassification improvement (NRI) and integrated discrimination improvement (IDI).

Results

Twenty-eight patients experienced thromboembolic events. The clinical model included age, aneurysm location, aneurysm dome and neck size, and treatment technique. AUC-ROC for the clinical model improved from 0.707 to 0.779 after adding the clopidogrel response value. Significant intergroup differences were noted in NRI (0.617, 95% CI: 0.247–0.987, p < .001) and IDI (0.068, 95% CI: 0.021–0.116, p = .005).

Conclusions

Evaluation of preoperative clopidogrel response in addition to clinical variables improves the prediction accuracy of thromboembolic event occurrence during/after coil embolization of unruptured intracranial aneurysm.

The Prophylactic Use of Tirofiban versus Oral Antiplatelet Medications in Stent-Assisted Coiling of Intracranial Aneurysms: A Meta-analysis

BACKGROUND

The protocol for optimal antiplatelet therapy to prevent thromboembolic and hemorrhagic complications in patients with cerebral aneurysms using an endovascular approach is not clear.

PURPOSE

Our study analyzed the safety and efficacy of prophylactic tirofiban administration compared with oral antiplatelet drug therapy.

DATA SOURCES

We used the PubMed, EMBASE, MEDLINE, and Cochrane library data bases.

STUDY SELECTION

Our study consisted of all case series with >5 patients that reported treatment-related outcomes of patients undergoing endovascular procedures pretreated with tirofiban or oral antiplatelet drug therapy.

DATA ANALYSIS

Random effects or fixed effects meta-analysis was used to pool the cumulative rate of complications, perioperative mortality, and good clinical outcomes.

DATA SYNTHESIS

Fifteen studies with 1981 patients were registered. Thromboembolic complications were significantly lower in the tirofiban group (3.6%; 95% CI, 1.9%-5.8%) compared with the dual-antiplatelet therapy group (8.5%, 95% CI, 4.5%-13%; P = .04). Pretreatment with tirofiban did not remarkably increase the rate of hemorrhagic complications (3.5%; 95% CI, 1.8%-5.6%) compared with dual-antiplatelet therapy (5.1%; 95% CI, 2.6%-8.5%; P = .371). There was a trend toward lower perioperative mortality with tirofiban (0.8%; 95% CI, 0.2%-1.6%) compared with dual-antiplatelet therapy (1.2%; 95% CI, 0.7%-2.0%; P = .412). There was no significant difference in the safety and efficacy between the tirofiban bolus plus drip and drip alone.

LIMITATIONS

The limitations are selection and publication biases.

CONCLUSIONS

Prophylactic therapy with tirofiban resulted in significantly lower rates of thromboembolic complications with no increase in hemorrhagic events or mortality than the prophylactic use of dual-antiplatelet therapy.

Active management of the target P2Y12 reaction unit range in patients undergoing stent-assisted coil embolization for unruptured cerebral aneurysms

BACKGROUND

Platelet function tests have been increasingly adopted to measure patient responses to antiplatelet drugs, and to predict complications. However, no established optimal antiplatelet management for stent-assisted coil embolization (SAC) have been established. The purpose of the present study was to investigate the efficacy and feasibility of clopidogrel dose adjustment for active target P2Y12 reaction unit (PRU).

METHODS

A total of 202 consecutive patients undergoing SAC to treat unruptured intracranial aneurysms were prospectively recruited. All patients were given two antiplatelet agents starting 7 days prior to the procedure, and platelet function was measured with the VerifyNow test. Clopidogrel hyper-responsive patients received reduced dosing according to the values of follow-up PRUs before and 7, 14, 30, and 90 days after the procedure. Patients were divided into three groups according to clopidogrel responsiveness before treatment, and clinical outcomes and time in target PRU ranges (TTR) were analyzed.

RESULTS

No delayed ischemic or hemorrhagic events occurred that were associated with out-of-range PRU. PRU values in the hypo-responsive and hyper-responsive groups significantly improved 7 days after treatment with active target PRU management (p=0.05,<0.001, respectively). PRU values were controlled within the target PRU range with drug adjustment (p=0.034), and the time in TTR for all patients was 97% (4.8%-100%), which showed the feasibility of optimal control of PRU values with the protocol.

CONCLUSION

Active target PRU management can achieve control of optimal PRU values and may decrease perioperative ischemic and hemorrhagic events among patients undergoing SAC.

P2Y12 inhibitors in neuroendovascular surgery: An opportunity for precision medicine

INTRODUCTION

Dual antiplatelet therapy (DAPT), primarily the combination of aspirin with a P2Y12 inhibitor, in patients undergoing intravascular stent or flow diverter placement remains the primary strategy to reduce device-related thromboembolic complications. However, selection, timing, and dosing of DAPT is critical and can be challenging given the existing significant inter- and intraindividual response variations to P2Y12 inhibitors.

METHODS

Assessment of indexed, peer-reviewed literature from 2000 to 2020 in interventional cardiology and neuroendovascular therapeutics with critical, peer-reviewed appraisal and extraction of evidence and strategies to utilize DAPT in cardio- and neurovascular patients with endoluminal devices.

RESULTS

Both geno- and phenotyping for DAPT are rapidly and conveniently available as point-of-care testing at a favorable cost-benefit ratio. Furthermore, systematic inclusion of a quantifying clinical risk score combined with an operator-linked, technical risk assessment for potential adverse events allows a more precise and individualized approach to new P2Y12 inhibitor therapy.

CONCLUSIONS

The latest evidence, primarily obtained from cardiovascular intervention trials, supports that combining patient pharmacogenetics with drug response monitoring, as part of an individually tailored, precision medicine approach, is both predictive and cost-effective in achieving and maintaining individual target platelet inhibition levels. Indirect evidence supports that this gain in optimizing drug responses translates to reducing main adverse events and overall treatment costs in patients undergoing DAPT after intracranial stent or flow diverting treatment.

Long-term outcomes of drug-eluting stent implantation in patients with symptomatic extra- and intracranial atherosclerotic stenoses

Objective

Implantation of drug-eluting stents (DES) for extra- and intracranial atherosclerotic stenoses is an emerging topic. It has the potential benefit of preventing recurrent stroke with a reduced rate of in-stent restenosis (ISR).

Methods

Patients who underwent extra- or intracranial stenting using DES in a single institution were retrospectively reviewed with long-term angiographic and clinical follow-up data.

Results

Twenty-one patients, 9 (42.9%) with extracranial lesions and 12 (57.1%) with intracranial lesions, were included. The most common symptom was cerebral infarction (71.4%), followed by vertebrobasilar insufficiency (19.1%) and transient ischemic attack (9.5%). All patients achieved technical success, with the mean degree of stenosis of 85.9±6.3% before the procedure and 19.5±5.9% after the procedure. All patients showed clinical improvement and no symptomatic recurrence was reported during the mean clinical follow-up period of 45.5±8.9 months. The significant ISR was observed in one patient (4.8%) during the mean radiological follow-up period of 42.8±10.0 months.

Conclusions

Implantation of drug-eluting stents for symptomatic extra- and intracranial atherosclerotic stenoses is feasible and has the potential benefit of reducing the rate of ISR.

Strategies to Prevent Ischemic Complications after Stent-assisted Coil Embolization of Cerebral Aneurysms

Objective

There have been no delayed ischemic complications related to stent-assisted coil embolization (SACE) of cerebral aneurysms at our institution. We demonstrate our strategies for stent placement and postoperative management of antiplatelet therapy to reduce the risk of ischemic complications.

Methods

We analyzed 57 cases of SACE retrospectively. In the procedure, an appropriate stent was selected and placed to fit the arterial wall without impeding on small arterial branches. Two different antiplatelet drugs, including clopidogrel, were used. Six to twelve months after surgery, follow-up angiography was performed to assess the safety of terminating antiplatelet therapy. In cases in which antiplatelet therapy was tapered, the two antiplatelet drugs were switched to clopidogrel alone, and it was subsequently tapered and finally discontinued.

Results

There were 49 cases of SACE in which postoperative antiplatelet therapy was tapered. Among these cases, antiplatelet therapy was discontinued in 35 cases. The mean duration of dual antiplatelet therapy was 10.6 ± 2.8 months, and the mean duration of total antiplatelet therapy was 15.0 ± 2.1 months. Three patients developed SACE-related ischemic stroke, which developed in the early phase after surgery in all.

Conclusion

Antiplatelet therapy can safely be terminated in most cases of SACE. In order to reduce the risk of ischemic complications, stent selection, stent placement, and management of antiplatelet therapy should be performed appropriately. Furthermore, careful follow-up should be continued even after the termination of antiplatelet therapy.

Thromboembolism during coiling of intracranial aneurysms: predictors and clinical outcome

Introduction

Thromboembolism is one of the most serious complications associated with coil embolization therapy.

Aim

To identify predisposing factors for thromboembolic complications, as well as to determine whether thromboembolism has an impact on clinical outcome.

Material and methods

From February 2008 to March 2015, 273 consecutive patients were treated at our institution via endovascular coil embolization. Patient medical records were reviewed with an emphasis on procedure description, potential risk factors and clinical outcomes related to thromboembolism. Thromboembolic incidents occurred in 19 (6.9%) cases. Multivariate logistic regression models were used to determine independent predictors of thromboembolism. Clinical outcome was analyzed using the Glasgow Outcome Scale (GOS).

Results

Multivariate analysis showed that subarachnoid hemorrhage was an independent risk factor for thromboembolic complications (p = 0.003; OR = 4.4; 95% CI: 1.67–12.02). The difference in frequency of perioperative mortality (GOS 1) in patients with thromboembolism and without thromboembolism was not statistically significant (p = 0.22). The differences in frequencies of severe disability (GOS 2–3) and moderate to low disability (GOS 4–5) between patients with thromboembolism and without thromboembolism were statistically significant in the general study population (p < 0.05).

Conclusions

Subarachnoid hemorrhage is an independent predictor of thromboembolic complications associated with endovascular coiling of cerebral aneurysms. Thromboembolism is associated with significantly increased risk of morbidity, and it affects to a certain extent the periprocedural mortality.

Is Vertebral Artery and Posterior Inferior Cerebellar Artery Dominance a Risk Factor for Thromboembolism During Coil Embolization of Unruptured Posterior Circulation Aneurysms?

BACKGROUND

To retrospectively analyze our clinical data to determine the risk factors for thromboembolism, especially with unruptured posterior circulation coil embolization.

METHODS

A total of 53 coil embolization procedures for unruptured posterior circulation aneurysms performed in 53 patients between October 2010 and August 2018 were included. Data about risk factors of thromboembolism in the medical records were collected, such as demographics (sex and age), diabetes mellitus, hypertension, dyslipidemia, smoking, and other underlying diseases. Data on the effect of antiplatelet agents were analyzed with the VerifyNow test. Angiographic data were analyzed to determine aneurysm location and maximum diameter of the aneurysm sac. In addition to these risk factors, relationships between the guiding catheter and anatomic variation of posterior circulation were also evaluated by dividing the cohort into 2 groups.

RESULTS

Thromboembolism was more likely to occur in the same-sided group (81.3% vs. 45.9%; P = 0.033). Accordingly, multivariate analysis revealed 2 risk factors for thromboembolism: same-sided (odds ratio [OR] = 6.12; 95%, confidence interval [CI], 1.369-27.387; P = 0.018) and stent deployment (OR, 3.90; 95% CI, 1.133-3.466; P = 0.031).

CONCLUSIONS

In cases of posterior circulation aneurysm coil embolization, if we place the guiding catheter into the side of the dominant posterior inferior cerebellar artery (PICA), then the risk of thromboembolism within the PICA territory could be higher. Accordingly, when faced with this situation, several solutions might be considered, such as changing the antiplatelet strategy or adding an intermediate catheter.

Safety and efficacy of a pre-treatment antiplatelet regimen of unruptured intracranial aneurysms: a single-center experience

PURPOSE

Endovascular treatment of unruptured intracranial aneurysms with stent-assisted coiling or flow diverter stents requires a prophylactic antiplatelet premedication to avoid thrombo-embolic complications. Guidelines for optimal antiplatelet regimens are poorly defined. The aim of this study is to report our experience using a high dosage antiplatelet premedication regimen for patients with unruptured intracranial aneurysms undergoing endovascular treatment by stent-assisted coiling or flow diverter stents.

METHODS

From a retrospective analysis of a prospectively maintained database, we collected clinical and angiographic data of 400 procedures in 362 patients treated by stent-assisted coiling or flow diverter stents for 419 unruptured intracranial aneurysms. Descriptive and analytic statistics were performed to report morbidity, mortality, and complication rates and to demonstrate associations between variables and outcomes. Logistic multivariable regression was performed to rule out confounding factors between subgroups.

RESULTS

Thrombo-embolic complications occurred in 23/400 procedures (5.75%) and hemorrhagic complications in 19/400 procedures (4.75%). The majority of complications were minor and transient with overall procedure-related morbidity and mortality rates of 1.75% (n = 7/400) and 1.25% (n = 5/400) respectively. The co-existence of multiple cardiovascular risk factors among smoking, hypertension, dyslipidemia, and age > 65 years old was significantly associated with permanent procedure-related morbidity (p = 0.006) and thrombo-embolic complications occurrence (p = 0.034). Age alone was associated with higher permanent morbidity (p = 0.029) and was the only variable associated with higher hemorrhagic complication (p = 0.024).

CONCLUSION

In this study, the use of a high dosage antiplatelet premedication was safe and effective for the treatment of unruptured intracranial aneurysms with stent-assisted coiling or flow diverter stents. Mortality and morbidity rates compare favorably with the current literature. The thrombo-embolic complications rate is low and most of them were clinically silent. However, the hemorrhagic complications rate was substantial and a significant proportion of them were associated with mortality.

Timing of Thrombosis in Embolization of Unruptured Intracranial Aneurysms : Tirofiban as Rescue Treatment

PURPOSE

Thrombosis is one of the main complications of endovascular treatment for unruptured intracranial aneurysms (UIA). This article reports the timing and initial location of thrombosis and prognosis after the use of tirofiban for performing coil embolization for UIA.

METHODS

This study retrospectively collected 1686 cases of intracranial aneurysms treated with coil embolization from January 2013 to February 2018. Ruptured cases were excluded. The presumed causes and timing of thrombosis, the response after tirofiban administration and the modified Rankin scale (mRS) score at 3 months were reviewed.

RESULTS

Of the 26 patients 76% were female and middle cerebral artery and basilar artery aneurysms accounted for 7 cases. The initial location of thrombosis was related to the stent (n = 14, 53.8%) or coil (n = 12, 46.2%). Of the patients 19 (73.1%) developed thrombosis during the procedure, and 5 patients (19.2%) developed it within 1 day of the procedure. Median duration between the thrombotic procedure and initial thrombosis was 38.5 min, 12 patients were symptomatic but more than half completely recovered after using tirofiban. Good clinical outcome (mRS 0-2) was seen in 92.3%. In the subgroup analysis, median time from the first thrombotic procedure to initial thrombosis within 1 day was 38.0 min (stent-related group) and 35.0 min (coil-related group, p = 0.651).

CONCLUSION

In most cases of embolization for UIA, thrombosis requiring the use of tirofiban occurs intraprocedurally or on the first day after the procedure. Careful observation of thrombosis during the procedure is important and tirofiban should be used for a better outcome even if the infarction progresses.

Coil Embolization for Unruptured Intracranial Aneurysms at the Dawn of Stent Era: Results of the Japanese Registry of Neuroendovascular Therapy (JR-NET) 3

Endosaccular coiling is recognized as a feasible method for treating unruptured intracranial aneurysms (UIAs). We retrospectively reviewed cases of UIAs treated by coiling in the Japanese Registry of Neuroendovascular Therapy (JR-NET) 3, a nationwide survey of NET between 2010 and 2014, the beginning period of intracranial stents in Japan. Data were extracted for 6844 UIAs (6619 procedures) from 40,169 registered records of all NETs in the JR-NET 3 databases. The features of the aneurysms and procedures, immediate radiographic findings, procedure-related complications, and clinical outcomes at 30 days after the procedures were assessed. Of 6844 UIAs, 81.8% were located in the anterior circulation. The mean patient age was 61.3 years (72.4% females). Compared with the preceding JR-NET 1 and 2, there were significant increases (P <0.05) in the rates of the following in JR-NET 3: wide-necked and small UIAs measuring <10 mm (from 56.4% to 58.8%), adjunctive techniques (54.8% to 71.8%), and stent usage (1.1% to 22.1%). Both pre- (85.6% to 96.7%) and post-procedural (84.0% to 94.6%) antiplatelet therapy were more frequently administered in JR-NET 3. Although procedure-related complication rates did not differ between the two groups, ischemic complication rates increased from 4.6% to 5.9%, leading to an increase in the 30-day morbidity (modified Rankin Scale >2) from 2.1% to 2.8%. In conclusion, introduction of neck-bridge stent was associated with an increase in cases of wide-necked aneurysms. However, the ischemic complication rate increased despite the greater use of periprocedural antiplatelet therapy.

Estimating short- and long-term reference change values and index of individuality for tests of platelet function

BACKGROUND

In order to manage risks of bleeding and thrombosis after some surgical procedures, platelet function is often measured repeatedly over days or weeks using laboratory tests of platelet function. To interpret test results in the perioperative period, it is necessary to understand analytical, biological and between-person variation.

METHODS

We collected three separate blood specimens from 16 healthy volunteers on the first study day, and one additional specimen from each volunteer 1, 2, and 3 months later. Arachidonic acid-induced and adenosine diphosphate (ADP)-induced platelet function were measured in duplicate by whole blood impedance aggregometry using Multiplate (ASPI/ADP tests) and VerifyNow (Aspirin Reaction Units [ARU] and P2Y12 Reaction Units [PRU]). The analytical variation (CV_A), within-subject variation (CV_I), between-subject variation (CV_G), index of individuality (II), and reference change values (RCV) were calculated.

RESULTS

VerifyNow ARU demonstrated the smallest short-term and long-term variability (CV_A, CV_I, and CV_G ~1%), resulting in short- and long-term RCV values <5%. II was also higher (1.92) for VerifyNow ARU than other platelet function tests. Multiplate ASPI and ADP tests had the highest RCV both short-(19.0% and 25.2%, respectively) and long-term (32.1% and 39.6%, respectively) due to increased CV_A (>5%) and CV_I (3.9-13.1%). VerifyNow PRU had a lower RCV than Multiplate ADP; but was the only test with II <0.6.

CONCLUSIONS

VerifyNow ARU results can be interpreted relative to a fixed cut-off or population-based reference interval; or relative to small changes in an individual's previous values. VerifyNow PRU and Multiplate ASPI and ADP tests should only be interpreted based upon relative change; and can only distinguish relatively large (>23%) changes over several weeks.

Whole blood aggregometry prior to Pipeline embolization device treatment of intracranial aneurysms: defining an optimal platelet inhibition cutoff value for clopidogrel

OBJECTIVE

Dual antiplatelet therapy is required for the treatment of intracranial aneurysms with the Pipeline embolization device (PED). Platelet function testing (PFT) is often used to assess the efficacy of the antiplatelet regimen prior to PED placement. The optimal impedance values for whole blood aggregometry in this setting have not been defined.

METHODS

A retrospective review of a prospectively maintained database was performed for the years 2011-2015 to identify patients with intracranial aneurysms treated with the PED who underwent pretreatment PFT using whole blood aggregometry. Antiplatelet therapy was not altered based on PFT results; all patients remained on standard doses of aspirin and clopidogrel. Clinical, radiographic, and laboratory data were analyzed to identify the optimal cutoff impedance value for clopidogrel responsiveness using the receiver operating characteristic curve and Youden's index.

RESULTS

Forty-nine patients underwent 53 endovascular procedures for the treatment of 76 aneurysms using the PED. The majority of these aneurysms were located in the anterior circulation (90.8%) and affected the internal carotid artery (89.5%). Patients in 30 procedures (56.6%) were identified as clopidogrel responders based on the manufacturer cutoff value (< 6 Ω). Thromboembolic complications occurred in 13 (24.5%) procedures; patients in 6 (11.3%) cases were symptomatic and those in 3 (5.7%) cases had ischemic strokes. Eleven of the 13 (84.6%) thromboembolic complications occurred in clopidogrel nonresponders. An impedance value of ≥ 6 Ω was independently associated with thromboembolic complications. The optimal electrical impedance value was identified as ≥ 6 Ω (sensitivity 84.6%, specificity 70.0%, area under the curve 0.77) for identifying clopidogrel nonresponders.

CONCLUSIONS

Thromboembolic complications are more common following PED placement in patients who do not respond adequately to clopidogrel. Clopidogrel nonresponders can be identified using pretreatment whole blood aggregometry. The optimal cutoff value to categorize a patient as a clopidogrel nonresponder when using whole blood aggregometry is ≥ 6 Ω.

The Efficacy of P2Y12 Reactive Unit to Predict the Periprocedural Thromboembolic and Hemorrhagic Complications According to Clopidogrel Responsiveness and Safety of Modification of Dual Antiplatelet Therapy : A Meta-Analysis

The efficacy of P2Y12 reaction unit (PRU) of VerifyNow still remains as a controversial issue in neurointervention. So we investigated the usefulness of PRU of VerifyNow to predict the peri-procedural thromboembolic events (TE) and hemorrhagic events (HE). And we evaluated the safety of modified dual antiplatelet therapy (DAPT) or triple antiplatelet therapy (TAPT) for clopidogrel hyporesponders. We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Web of Science and Scopus on August 19 2018. Data was collected the 1) incidence of TE between clopidogrel responder and clopidogrel hypo-responder, 2) incidence of HE between clopidogrel hyper-responder and clopidogrel responder and hypo-responder, and 3) incidence of TE and HE between modified DAPT or TAPT and standard DAPT in clopidogrel hypo-responder. High cut-off value of PRU was defined as PRU >40% or <220. Fifteen studies were enrolled. Clopidogrel responder showed lower incidence of TE than hypo-responder (risk ratio [RR], 0.32; 95% confidence interval [CI], 0.17-0.61; p<0.001). With the high cut-off value of PRU, clopidogrel responder showed more lower incidence of TE than hypo-responder (RR, 0.11; 95% CI, 0.02-0.45; p=0.002). The incidence of periprocedural HE have higher on clopidogrel hyper-responder than clopidogrel responder and hypo-responder (RR, 4.26; 95% CI, 1.10-16.44; p=0.04; I2=66%). The incidence of periprocedural TE after changing regimen of DAPT for clopidogrel hypo-responder have a tendency to reduce, but there was no significant difference between modified DAPT or TAPT group and standard DAPT group (p>0.05). The incidence of periprocedural HE after changing regimen of DAPT for clopidogrel hypo-responder was no significant difference between modified DAPT or TAPT group and standard DAPT group (p>0.05). PRU is a useful tool as a predictor of peri-procedural TE or HE on neurointervention. PRU has a threshold effect of cut-off value to predict the peri-procedural TE. Modified DAPT or TAPT to prevent TE in clopidogrel hypo-responders could not reduce the incidence of TE. We should investigate the further research about modification of regiment on neurointervention.

Antiplatelet therapy for prevention of thromboembolic complications in coiling-only procedures for unruptured brain aneurysms

BACKGROUND AND PURPOSE

Thromboembolic events are recognized complications of aneurysm coiling.

OBJECTIVE

To identify any protective effects of antiplatelet therapy use before coiling of unruptured aneurysms.

METHODS

We conducted a meta-analysis of clinical studies published up to February 2019. We included studies reporting symptomatic thromboembolic events (defined as clinical stroke or transient ischemic attacks) in patients who received antiplatelet therapy before coiling of unruptured aneurysms using unassisted coiling, balloon assistance, or multiple microcatheters. We excluded ruptured aneurysms and those treated with stent coiling or flow diverters.

RESULTS

We identified 14 studies (2486 patients). All were single-center studies and four were prospective. In three studies with a control (no treatment) arm, the pooled risk ratio for symptomatic thromboembolic events with versus without antiplatelet therapy was 0.33 (95% CI 0.17 to 0.92, p= 0.035). The cumulative risk of symptomatic thromboembolic events with single antiplatelet agents was 5.0% '56/1122' (95% CI 1.6% to 8.4%, I²83.63%), and with dual or multiple agents 2.7% '33/1237' (95% CI 1.0% to 3.0%, I²39.9%). The incidence of diffusion lesions was reported in seven studies. It was 50.5% '96/190' (95% CI 7.3% to 93.9%, I²94.4%) with single agents compared with 43.9% '196/446' (95% CI 25.9% to 61.9%, I²73.4%) with dual or multiple agents.

CONCLUSION

Periprocedural antiplatelet therapy was associated with a low symptomatic thromboembolic event after coiling-only for unruptured aneurysms. However, available evidence is of limited quality with significant heterogeneity, requiring evidence from randomized controlled trials.

Different Clopidogrel Response Elicited by Lansoprazole or Esomeprazole in Patients Undergoing Neurointervention with Dual Antiplatelet Therapy

BACKGROUND

Aspirin-clopidogrel dual antiplatelet therapy and a proton-pump inhibitor are used worldwide to prevent thromboembolism and peptic ulceration in patients undergoing neurointervention. We performed VerifyNow assays (Accumetrics, San Diego, CA, USA) to retrospectively examine the relationship between the effectiveness of antiplatelet agents and different proton-pump inhibitor types.

METHODS

Sixty-four patients with unruptured intracranial aneurysm scheduled for neurointervention received aspirin-clopidogrel dual antiplatelet therapy plus the proton-pump inhibitor lansoprazole (n = 34) or esomeprazole (n = 30). A low response to aspirin and clopidogrel was defined in terms of aspirin reaction units > 550 and P2Y12 reaction units ≥ 230, respectively, by VerifyNow assay. The characteristics, response to antiplatelet therapy, and clinical outcomes were compared in patients treated with lansoprazole or esomeprazole.

RESULTS

The preoperative mean VerifyNow aspirin reaction units and P2Y12 reaction units were 466.0 ± 67.3 and 205.0 ± 67.6, respectively. The mean aspirin reaction unit value was 482.0 ± 64.1 in the lansoprazole group, and 461.5 ± 70.9 in the esomeprazole group (p = 0.77). The mean P2Y12 reaction unit was 220.0 ± 64.4 in the lansoprazole group, and 174.5 ± 65.0 in the esomeprazole group; there was a significant difference in the clopidogrel response of patient treated with lansoprazole or esomeprazole (p = 0.005).

CONCLUSIONS

Our VerifyNow assay results suggest that when on lansoprazole fewer patients achieved the therapeutic goal and required extra therapy before neurointervention.

Association of Thrombelastographic Parameters with Complications in Patients with Intracranial Aneurysm After Stent Placement

OBJECTIVE

A prospective trial was conducted to investigate the platelet function and association between thrombelastographic (TEG) parameters and embolic or hemorrhagic complications in patients with intracranial aneurysm undergoing stent treatment.

METHODS

Between September 2013 and June 2016, we prospectively recruited patients with intracranial aneurysm who were treated with stent-assisted coiling. TEG parameters were used to assess the platelet function before stenting procedures. The primary study end point was the onset of ischemic stroke, transient ischemic attack, or silent ischemic events in the territory of the stented artery within 6 months after the procedure. The secondary end point was assessed by bleeding events.

RESULTS

Four hundred and thirty-one patients with 453 intracranial aneurysms were enrolled. A total of 519 neurovascular stents were implanted. During the follow-up, a total of 70 primary end points (16.2%) and 59 secondary end points (13.7%) were detected. Thromboembolic complications such as symptomatic and slient ischemic complications were more frequently observed in patients with large aneurysms (>10 mm, P = 0.01), lower adenosine diphosphate (ADP) inhibition rate (P < 0.0001), and higher ADP-induced platelet-fibrin clot strength (maximum amplitude of adenosine diphosphate [MA-ADP]) (P < 0.0001). Besides, based on multivariate analysis, a higher ADP inhibition ratio was identified as a significant independent predictor of subsequent bleeding events (P < 0.0001). According to the receiver operating characteristic curve analysis, the safe range of the ADP inhibition ratio and MA-ADP of the TEG analysis were identified as 29.45%-55.4% and <46.15, respectively.

CONCLUSIONS

The ADP inhibition ratio and MA-ADP of TEG analysis were associated with subsequent cerebral ischemic events and intracranial or extracranial bleeding events in patients with intracranial aneurysm after stent treatment.

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.

Procedural Clinical Complications, Case-Fatality Risks, and Risk Factors in Endovascular and Neurosurgical Treatment of Unruptured Intracranial Aneurysms: A Systematic Review and Meta-analysis

Importance

The risk of procedural clinical complications and the case-fatality rate (CFR) from preventive treatment of unruptured intracranial aneurysms varies between studies and may depend on treatment modality and risk factors.

Objective

To assess current procedural clinical 30-day complications and the CFR from endovascular treatment (EVT) and neurosurgical treatment (NST) of unruptured intracranial aneurysms and risk factors of clinical complications.

Data Sources

We searched PubMed, Excerpta Medica Database, and the Cochrane Database for studies published between January 1, 2011, and January 1, 2017.

Study Selection

Studies reporting on clinical complications, the CFR, and risk factors, including 50 patients or more undergoing EVT or NST for saccular unruptured intracranial aneurysms after January 1, 2000, were eligible.

Data Extraction and Synthesis

Per treatment modality, we analyzed clinical complication risk and the CFR with mixed-effects logistic regression models for dichotomous data. For studies reporting data on complication risk factors, we obtained risk ratios (RRs) or odds ratios (ORs) with 95% CIs and pooled risk estimates with weighted random-effects models.

Main Outcomes and Measures

Clinical complications within 30 days and the CFR.

Results

We included 114 studies (106 433 patients with 108 263 aneurysms). For EVT (74 studies), the pooled clinical complication risk was 4.96% (95% CI, 4.00%-6.12%), and the CFR was 0.30% (95% CI, 0.20%-0.40%). Factors associated with complications from EVT were female sex (pooled OR, 1.06 [95% CI, 1.01-1.11]), diabetes (OR, 1.81 [95% CI, 1.05-3.13]), hyperlipidemia (OR, 1.76 [95% CI, 1.3-2.37]), cardiac comorbidity (OR, 2.27 [95% CI, 1.53-3.37]), wide aneurysm neck (>4 mm or dome-to-neck ratio >1.5; OR, 1.71 [95% CI, 1.38-2.11]), posterior circulation aneurysm (OR, 1.42 [95% CI, 1.15-1.74]), stent-assisted coiling (OR, 1.82 [95% CI, 1.16-2.85]), and stenting (OR, 3.43 [95% CI, 1.45-8.09]). For NST (54 studies), the pooled complication risk was 8.34% (95% CI, 6.25%-11.10%) and the CFR was 0.10% (95% CI, 0.00%-0.20%). Factors associated with complications from NST were age (OR per year increase, 1.02 [95% CI, 1.01-1.02]), female sex (OR, 0.43 [95% CI, 0.32-0.85]), coagulopathy (OR, 2.14 [95% CI, 1.13-4.06]), use of anticoagulation (OR, 6.36 [95% CI, 2.55-15.85]), smoking (OR, 1.95 [95% CI, 1.36-2.79]), hypertension (OR, 1.45 [95% CI, 1.03-2.03]), diabetes (OR, 2.38 [95% CI, 1.54-3.67]), congestive heart failure (OR, 2.71 [95% CI, 1.57-4.69]), posterior aneurysm location (OR, 7.25 [95% CI, 3.70-14.20]), and aneurysm calcification (OR, 2.89 [95% CI, 1.35-6.18]).

Conclusions and Relevance

This study identifies risk factors for procedural complications. Large data sets with individual patient data are needed to develop and validate prediction scores for absolute complication risks and CFRs from EVT and NST modalities.

Endovascular Treatment of Unruptured MCA Bifurcation Aneurysms Regardless of Aneurysm Morphology: Short- and Long-Term Follow-Up

BACKGROUND AND PURPOSE

The optimal treatment of unruptured middle cerebral aneurysms is still under debate. Although today almost any aneurysm can be treated endovascularly, there is a lack of data comparing endovascular and microsurgical repair of MCA aneurysms. The aim of our analysis is to provide data on the efficacy, clinical outcome, complications and re-treatment rates of endovascular treatment of this subtype of aneurysms.

MATERIALS AND METHODS

Between May 2008 and July 2017, endovascular treatment of 1184 aneurysms in 827 patients was performed in our department. Twenty-four percent of these aneurysms were located at the MCA, and 150 unruptured MCA bifurcation aneurysms treated with coiling, stent-assisted-coiling, or endovascular flow diverter (WEB device) were identified for this retrospective data analysis. Ninety-six percent of all aneurysms, ruptured and unruptured, were treated by an endovascular approach, which yields a low selection bias for aneurysms suitable for endovascular treatment. Follow-up examinations were performed after 12 and 36 months and then every 1-3 years after embolization. Procedures were analyzed for periprocedural complications, outcome, and retreatment rate of the WEB (n = 38) and coiling with (n = 45) or without stent assistance (n = 67).

RESULTS

The procedure-associated good clinical outcome (mRS ≦ 2) was 89.9%, and the mortality rate was 2.7%. Short-term follow-up good clinical outcome/mortality rates were 91.3%/0.7%. At discharge, 137 patients had an mRS of 0-2 (91.3%) and 13 had an mRS of 3-6 (8.7%). The retreatment rate was significantly higher in the WEB group (21.1%) compared with the coiling group with (5.9%) or without (2.2%) stent placement (P < .05).

CONCLUSIONS

Regardless of the architecture of MCA bifurcation aneurysms, the endovascular treatment can be performed with low morbidity/mortality rates. The higher retreatment rate in the WEB group correlates with the learning curve in choosing the right device size.

Comparison of Clopidogrel and Ticlopidine/Ginkgo Biloba in Patients With Clopidogrel Resistance and Carotid Stenting

Background and Purpose: Patients undergoing carotid artery stenting (CAS) who show low responsiveness to clopidogrel may have a higher risk of peri-procedural embolic events. This study aimed to compare the effectiveness and safety of clopidogrel and ticlopidine plus Ginkgo biloba in clopidogrel-resistant patients undergoing CAS.

Methods: In this multi-center, randomized, controlled trial, we used platelet reactivity test to select patients undergoing CAS who showed clopidogrel resistance, and compared treatments using clopidogrel and ticlopidine plus ginkgo. The primary outcome was the incidence of new ischemic lesion in the ipsilateral hemisphere of CAS. Detection of microembolic signal on transcranial Doppler was the secondary outcome. The clinical outcomes were also monitored.

Results: This trial was discontinued after 42 patients were randomized after preplanned interim sample size re-estimation indicated an impractical sample size. The primary endpoint occurred in 12/22 patients (54.5%) in the clopidogrel group and 13/20 patients (65.0%) in the ticlopidine–ginkgo group (P = 0.610). No significant differences in the presence of microembolic signal (15.0 vs. 11.8%, P = 0.580), clinical outcomes (ischemic stroke or transient ischemic attack, 0.0 vs. 5.5%; acute myocardial infarction 0.0 vs. 0.0%; all-cause death, 4.5 vs. 0.0%), or incidence of adverse events were found in the two groups. In terms of resistance to clopidogrel, treatment with ticlopidine–ginkgo significantly increased the P2Y12 Reaction Units (difference, 0.0 [−0.3–3.0] vs. 21.0 [6.0–35.0], P < 0.001).

Conclusions: In patients who showed clopidogrel resistance, ticlopidine–ginkgo treatment was safe and increased P2Y12 Reaction Units; however, compared to clopidogrel, it failed to improve surrogate and clinical endpoints in patients undergoing CAS. This multimodal biomarker-based clinical trial is feasible in neurointerventional research.

Clinical Trial Registration:http://www.clinicaltrials.gov. Unique identifier: NCT02133989.

Variability of Platelet Reactivity on Antiplatelet Therapy in Neurointervention Procedure

As more intracranial aneurysms and other cerebrovascular pathologies are treated with neurointervention procedure, thromboembolic events that frequently lead to serious neurological deficit or fatal outcomes are increasing. In order to prevent the thromboembolic events, antiplatelet therapy is used in most procedures including coil embolization, stenting, and flow diversion. However, because of variable individual pharmacodynamics responses to antiplatelet drugs, especially clopidogrel, it is difficult for clinicians to select the adequate antiplatelet regimen and its optimal dose. This article reviews the neurointervention literature related to antiplatelet therapy and suggests a strategy for tailoring antiplatelet therapy in individual patients undergoing neurointervention based on the results of platelet function testing.

Management of antiplatelet therapy in patients undergoing neuroendovascular procedures

Neuroendovascular techniques for treating cerebral aneurysms and other cerebrovascular pathology are increasingly becoming the standard of care. Intraluminal stents, aneurysm coils, and other flow diversion devices typically require concomitant antiplatelet therapy to reduce thromboembolic complications. The variability inherent with the pharmacodynamic response to common antiplatelet agents such as aspirin and clopidogrel complicates optimal selection of antiplatelet agents by clinicians. This review serves to discuss the literature related to antiplatelet use in neuroendovascular procedures and provides recommendations for clinicians on how to approach patients with variable response to antiplatelet agents, particularly clopidogrel.

Precision of VerifyNow P2Y12 Assessment of Clopidogrel Response in Patients Undergoing Cerebral Aneurysm Flow Diversion

Background

Dual antiplatelet therapy (DAT), most commonly with aspirin and Clopidogrel, is the standard of care for intracranial stenting, including flow diversion. Clopidogrel response varies by individual.

Objective

To investigate the real-world precision of VerifyNow P2Y12 assessment (Accumetrics, San Diego, California) of Clopidogrel response.

Methods

Using a prospectively-collected, IRB-approved cerebral aneurysm database 643 patients were identified who were treated with the Pipeline embolization device from 2011 to 2017. Patients with multiple P2Y12 assays drawn within a 24-h window were identified. A single patient could contribute multiple, independent sets. Levels drawn before a 5-d course of DAT and patients who received alternative antiplatelet agents were excluded. Therapeutic range was defined as platelet reaction units (PRU) 60–200.

Results

A total of 1586 P2Y12 measurements were recorded; 293 (46%) patients had more than one assay. One hundred forty (22%) patients had multiple P2Y12 measurements within 24 h. These patients accounted for 230 independent 24-h sets. The average P2Y12 fluctuation across all sets was 35 points; the 25th, 50th, and 75th percentiles were 12, 26, and 48 points, respectively. Of the 230 24-h sets of P2Y12 assays, 76% remained within their original therapeutic category: 100 (43%) all therapeutic, 54 (23%) all hypo-responsive, and 21 (9%) all hyper-responsive. Twenty-four percent of patients fluctuated between therapeutic categories when multiple P2Y12 assessments were drawn within a 24-h period: 29 (13%) between hypo-response and therapeutic, 23 (10%) between hyper-response and therapeutic, and 3 (1%) between hypo-response and hyper-response.

CONCLUSION

Our experience suggests P2Y12 is an often-imprecise measure, and this should be considered when utilizing P2Y12 levels for clinical decisions.

The safety of triple antiplatelet therapy under thromboelastography guidance in patients undergoing stenting for ischemic cerebrovascular disease

OBJECTIVE

To investigate the safety of triple antiplatelet therapy (TAT) with cilostazol in patients undergoing stenting for extracranial and/or intracranial artery stenosis.

METHODS

A prospectively collected database was reviewed to identify patients who underwent stenting for extracranial and/or intracranial artery stenosis and showed resistance to aspirin and/or clopidogrel as assessed by pre-stenting thromboelastography (TEG) testing. Patients were assigned to a TAT group and a dual antiplatelet therapy (DAT) group. Major complications were defined as thromboembolic events (transient ischemic attack (TIA), ischemic stroke, and stent thrombosis) or major bleeding events within 30 days, and minor complications were defined as extracranial bleeding that did not require vascular surgery or transfusion within 30 days.

RESULTS

A total of 183 patients were identified. The incidence of major complications was significantly lower in the TAT group than in the DAT group (TAT group vs. DAT group, 1/110 vs. 6/73; P=0.017). TIAs occurred in four patients, with one in the TAT group and three in the DAT group (1/110 vs. 3/73; P=0.303). Ischemic strokes occurred in three patients in the DAT group (TAT group vs. DAT group, P=0.062). No major bleeding events or stent thrombosis was recorded in either group. Two patients (one in each group) experienced minor complications that resolved without additional treatment (1/110 vs. 1/73; P>0.999).

CONCLUSIONS

TAT under TEG guidance appears to be a safe antiplatelet strategy in patients undergoing stenting for extracranial and/or intracranial artery stenosis. By employing TAT under TEG guidance, favorable outcomes can be achieved in these patients.