Low-Dose Prasugrel vs Clopidogrel-Based Tailored Premedication for Endovascular Treatment of Cerebral Aneurysms

Efficacy and Safety of Dual Antiplatelet Therapy with the Routine Use of Prasugrel for Flow Diversion of Cerebral Unruptured Aneurysms

PURPOSE

Prasugrel is not approved for patients treated with flow diverters, which have a high metal coverage ratio. However, robust antiplatelet therapy with prasugrel may prevent thromboembolic complications. We administered prasugrel and aspirin to all patients treated with flow diverters and reported the safety of the antiplatelet therapy regimen.

METHODS

This retrospective, single-center study evaluated the angiographic and clinical data of consecutive patients treated with flow diverters for cerebral unruptured aneurysms between June 2020 and May 2022. All patients received dual antiplatelet therapy, including prasugrel and aspirin. The administration of prasugrel ended 3 or 6 months after the procedure, whereas aspirin use continued for at least 12 months. Periprocedural complications (< 30 days post-procedure) and delayed complications (> 30 days post-procedure) were recorded.

RESULTS

During the study period, 120 unruptured aneurysms were treated with flow diverters in 110 patients. All patients, except one, survived longer than 12 months after the procedure. The rate of thromboembolic complications was 6.4%, and more than half of the patients had transient symptoms; one (0.9%) had a major ischemic stroke. One patient (0.9%) each had an asymptomatic, small subarachnoid hemorrhage and significant hemorrhagic complications with melena. The rate of permanent neurological deficits was 1.8%, and the mortality rate was 0.9%.

CONCLUSIONS

Dual antiplatelet therapy comprising routine use of prasugrel and aspirin for flow diverter-implanted patients possibly contributed to a low rate of thromboembolic complications and low risk of hemorrhagic complications.

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.

Endovascular Treatment of Intracranial Aneurysms Using a Microcatheter Protection

PURPOSE

Stent protective or balloon remodeling techniques have enabled coil embolization of complexly configured aneurysms. Still, the utility of such methods may be limited in some small-caliber and/or inherently tortuous lesions. The present study was conducted to examine the efficacy of microcatheter protection (MCP) when applied in these circumstances.

METHODS

This retrospective review included 432 patients with 452 intracranial aneurysms subjected to MCP between April 2001 and January 2021. All available medical records and radiologic data were analyzed, focusing on strategic, safety, and efficacy aspects of the procedures.

RESULTS

In a majority (255/452, 56.4%) of cases, MCP was applied throughout entire coiling procedures, as opposed to coil framing (137/452, 30.3%) or filling/finishing (60/452, 13.3%) only. Lesions of the middle cerebral artery (54.9%) predominated, followed by anterior (12.4%) and posterior (11.1%) communicating artery aneurysms. Stent protection was also used occasionally (46/452, 10.2%). Procedural morbidity was low (3/432, 0.7%), limited to symptomatic thromboembolism and procedural leakage, and there were no deaths. Occlusion was successfully achieved by MCP in 424 aneurysms (93.8%). During the follow-up period (mean, 43.4 ± 30.4 months), satisfactory occlusion was documented in 406 of 440 (92.3%) aneurysms.

CONCLUSION

MCP is feasible and safe for coil embolization of intracranial aneurysms, in conjunction with multicatheter, balloon, or stenting techniques. MCP may have merit in small-sized or tortuous lesions not amenable to balloon or stent usage, often eliminating the need for stenting altogether.

Safety and efficacy of tailored antiplatelet therapy using prasugrel or ticagrelor based on clopidogrel responsiveness in endovascular treatment for intracranial aneurysms: a meta-analysis

BACKGROUND

Clopidogrel (CPG)-based dual antiplatelet therapy (DAPT) in combination with aspirin has been widely used before endovascular procedures for intracranial aneurysms to prevent procedural thromboembolic complication (TEC). However, the main drawback of CPG is the high proportion of hyporesponders. This study sought to investigate the usefulness of tailored DAPT using novel P2Y12 inhibitors (prasugrel or ticagrelor, (PSG/TCG)) guided by a platelet reactivity test (PRT), compared with CPG-based conventional DAPT.

METHOD

Data were extracted from PubMed, Embase, and Cochrane Central Register of Controlled Trials by two independent reviewers. A random effects model was used to investigate the procedural TEC and hemorrhagic complications (HEC) of the tailored DAPT and conventional therapy by risk ratios (RR) and 95% confidence intervals (95% CI). Additionally, we performed subgroup analyses to directly compare prasugrel/ticagrelor with CPG.

RESULTS

Six studies comprising 2557 patients were included in the analysis. Compared with conventional non-tailored therapy, PRT-guided tailored DAPT with PSG/TCG was associated with a lower risk of TEC (RR 0.40, 95% CI 0.22 to 0.74, P=0.004) without increasing HEC rates. The subgroup analysis showed that the switch to PSG/TCG in CPG hyporesponders was related to a lower incidence of TEC (RR 0.46, 95% CI 0.23 to 0.95, P=0.03) without a difference in HEC, compared with maintenance of CPG in CPG responders.

CONCLUSION

Evidence from this analysis supports PRT-guided tailored DAPT (using PSG/TCG) as a better choice for preparation towards endovascular procedures to treat aneurysms. Furthermore, it suggests that PSG/TCG is not limited to the role of a substitute for CPG but may be a first-line agent for DAPT.

Variability of response on prophylactic prasugrel for endovascular treatment of intracranial aneurysms: Clinical implications

BACKGROUND AND PURPOSE

Prophylactic prasugrel for endovascular treatment of intracranial aneurysms has been introduced and increased, but HTPR (high on-treatment platelet reactivity) or LTPR (low on-treatment platelet reactivity) of prasugrel is not uncommon in clinical circumstances. To investigate the predisposing factors of HTPR and LTPR on prasugrel premedication in the neurointerventional field and to determine its clinical implications.

MATERIALS AND METHODS

Between February 2016 and December 2020, 191 patients treated with coil embolization using prophylactic prasugrel in 234 intracranial aneurysms were the final candidates for this study. Patient and aneurysm characteristics, clinical status, and laboratory study values were carefully reviewed retrospectively. We performed risk factor analyses for HTPR and LTPR on prasugrel.

RESULTS

Ultimately, 20 patients (10.5%) had HTPR, and 74 patients (38.7%) were categorized as having LTPR. In multivariable analyses, the factors related to HTPR were BMI (adjusted OR 1.21, 95% CI 1.04-1.41, p = 0.01), history of antithrombotics (adjusted OR 3.79, 95% CI 1.39-10.34, p = 0.01), and hematocrit (adjusted OR 0.91, 95% CI 0.84-0.99, p = 0.03). Low BMI was the only risk factor for LTPR (adjusted OR 0.84, 95% CI 0.76-0.94, p = 0.001).

CONCLUSION

In the neurointerventional field, high BMI and prior use of antithrombotic agents were related to HTPR, and low BMI was associated with LTPR on prophylactic prasugrel. High hematocrit levels decreased the risk of HTPR. When preparing endovascular treatment for intracranial aneurysms, attention to patients with these clinical features is required to address the possibility of ischemic or bleeding complications.

Safety and Efficacy of Low-dose Prasugrel in the Endovascular Treatment of Unruptured Aneurysms in the Elders (≥ 75 Years)

PURPOSE

The effectiveness and safety of low-dose prasugrel (PSG) premedication for endovascular treatment of unruptured intracranial aneurysms (UIAs) have been widely reported. In this study, we evaluated the clinical outcomes of elders patients (≥ 75 years) treated with PSG.

METHODS

A total of 200 patients with 209 UIAs who were administered PSG as premedication (20 mg loading and 5 mg maintenance with 100 mg aspirin) between March 2018 and December 2021 were retrospectively enrolled. Among them, 39 patients were aged 75 years or over (elders group), and 161 patients were aged under 75 years (control group). Patients' clinical data were collected, and outcomes were compared between the two groups.

RESULTS

Of the 200 patients with PSG, 9 cases (4.5%) had overall complications (7 ischemic, 2 hemorrhagic). In the comparison between the elders group and the control group, no significant differences were observed in the overall complication rates (elders group vs. control group; 2.6% vs. 5.0%, P = 1.00). Moreover, the rates of poor clinical outcome were comparable (2.6% vs. 1.2%, P = 0.48). The subgroup analysis of patients with stent-assisted procedures revealed no significant differences in complication rates (0% vs. 1.6%, P = 1.00) or poor clinical outcomes (0% vs. 0%, P = 1.00) during maintenance with aspirin 100 mg or PSG 5 mg.

CONCLUSION

The complication rates in the elders treated with low-dose PSG premedication were similar to those in the control. Low-dose PSG premedication could be prescribed without any additional risk for the endovascular treatment of UIAs in elders patients.

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.

Antiplatelet Drugs for Neurointerventions: Part 2 Clinical Applications

Endovascular techniques have expanded to include balloon and stent-assistance, flow diversion and individualized endovascular occlusion devices, to widen the treatment spectrum for more complex aneurysm morphologies. While usually well-tolerated by patients, endovascular treatment of intracranial aneurysms carries the risk of complications, with procedure-related ischemic complications being the most common. Several antiplatelet agents have been studied in a neurointerventional setting for both prophylaxis and in the setting of intraprocedural thrombotic complications. Knowledge of these antiplatelet agents, evidence for their use and common dosages is important for the practicing neurointerventionist to ensure the proper application of these agents.Part one of this two-part review focused on basic platelet physiology, pharmacology of common antiplatelet medications and future directions and therapies. Part two focuses on clinical applications and evidence based therapeutic regimens.

The Fate of Partially Thrombosed Intracranial Aneurysms Treated with Endovascular Intervention

Objective

The fate of partially thrombosed intracranial aneurysms (PTIAs) is not well known after endovascular treatment. The authors aimed to analyze the treatment outcomes of PTIAs.

Methods

We retrospectively reviewed the medical records of 27 PTIAs treated with endovascular intervention between January 1999 and March 2018. Twenty-one aneurysms were treated with intraluminal embolization (ILE), and six were treated with parent artery occlusion (PAO) with or without bypass surgery. Radiological results, clinical outcomes and risk factors for major recurrence were assessed.

Results

The initial clinical status was similar in both groups; however, the last status was better in the ILE group than in the PAO group (p=0.049). Neurological deterioration resulted from mass effect in one case and rupture in one after ILE, and mass effect in two and perforator infarction in one after PAO. Twenty cases (94.2%) in the ILE group initially achieved complete occlusion or residual neck status. However, 13 cases (61.9%) showed major recurrence, the major causes of which included coil migration or compaction. Seven cases (33.3%) ultimately achieved residual sac status after repeat treatment. In the PAO group, all initially showed complete occlusion or a residual neck, and just one case ultimately had a residual sac. Two cases showed major recurrence, the cause of which was incomplete PAO. Aneurysm wall calcification was the only significantly protective factor against major recurrence (odds ratio, 36.12; 95% confidence interval, 1.85 to 705.18; p=0.018).

Conclusion

Complete PAO of PTIAs is the best option if treatment-related complications can be minimized. Simple fluoroscopy is a useful imaging modality because of the recurrence pattern.

Reduction of thromboembolic complications during the endovascular treatment of unruptured aneurysms by employing a tailored dual antiplatelet regimen using aspirin and prasugrel

Background

Thromboembolic complications (TECs) are frequent during the endovascular treatment of unruptured aneurysms. To prevent TECs, dual antiplatelet therapy using aspirin and clopidogrel is recommended for the perioperative period. In patients with a poor response, clopidogrel is a risk factor for TECs. To prevent TECs, our study assessed the stratified use of prasugrel.

Methods

Patients who underwent endovascular therapy for unruptured cerebral aneurysms from April 2017 to August 2019 were enrolled in this clinical study and given premedication with aspirin and clopidogrel for 2 weeks prior to the procedure. P2Y12 reaction units (PRU) were measured using the VerifyNow assay on the day before the procedure (tailored group). In subgroups with PRU <240, the clopidogrel dose was maintained (CPG subgroup). In subgroups with PRU ≥240, clopidogrel was changed to prasugrel (PSG subgroup). We compared the occurrence of TECs with retrospective consecutive cases from January 2015 to March 2017 without PRU assessments (non-tailored group). The frequency of TECs within 30 days was assessed as the primary endpoint.

Results

The tailored and non-tailored groups comprised 167 and 50 patients, respectively. TECs occurred in 11 (6.6%) and 8 (16%) patients in the tailored and non-tailored groups (P=0.048), respectively. The HR for TECs was significantly reduced in the tailored group (HR 0.3, 95% CI 0.11 to 0.81); P=0.017) compared with the non-tailored group.

Conclusion

The results suggest that tailored dual antiplatelet therapy medication with PRU significantly reduces the frequency of TECs without increasing hemorrhagic complications.

Tailored antiplatelet agent medication in clopidogrel hyporesponsive patients before stent-assisted coiling: single-center experience

PURPOSE

In patients requiring stent procedures, resistance or hyperresponsiveness to antiplatelet medications is often observed. This study aims to evaluate the efficacy and safety of tailoring medications in these patients.

METHODS

This retrospective study included 223 patients who underwent endovascular treatment for intracranial aneurysm between October 2018 and October 2019. Patients were categorized as hyporesponsive, hyperresponsive, and normoresponsive groups according to the initial PRU response. For the hypo- or hyperresponders, we tailored medication by modifying the dose or changing the drug. PRUs before and after tailoring were compared in each group. PRU reponses in patients who underwent Cytochrome P450 2C19 (CYP2C19) genotyping were also determined.

RESULTS

Of the 73 clopidogrel-resistant patients, the mean PRU values after tailoring showed a greater decrease in the group that switched to prasugrel (n = 56), from 223 to 131, than in the clopidogrel reloading group (n = 17), from 238 to 209. In 31 hyperresponders, PRU increased from 49 to 94 after the dose adjustment. CYP2C19 genotyping showed that PRU tended to increase as the number of mutated alleles increased. There were five (2.3%) ischemic events (three transient ischemic attacks and two minor strokes) in a mean follow-up of 8 months, but no hemorrhage.

CONCLUSIONS

The stent-assisted coiling was successfully performed with acceptable range of ischemic events and without hemorrhage in all patients, including those who applied tailored medication. Low-dose prasugrel was effective for obtaining appropriate PRU values for initial medication as well as for clopidogrel-resistant patients. The genetic test did not provide reliable results in determining clopidogrel resistance.

[Endovascular Treatment of Cerebral Aneurysms: Technical Options in Coil Embolization]

Since the endosaccular coil embolization technique was introduced as an alternative for treating selected patients with aneurysms, it has become a mainstay of treatment for cerebral aneurysms. In lesions with a neck larger than the aneurysmal body, an irregular shape, or arterial branches incorporated within the sac, endovascular treatment using detachable coils are traditionally contraindicated because of technical difficulties. Coil embolization has evolved as a result of both the development of related devices and the introduction of technical improvements using various devices. Use of various technical and device options can make endovascular treatment of cerebral aneurysms safer and can widen the treatment indications. Various technical options, including the technical modification of device-assisted techniques, will be presented, and the related practical points will be discussed in this issue.

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.

The Usefulness of Prasugrel as Rescue Medication in Neuroendovascular Therapy

Objective

In neuroendovascular therapy, clopidogrel resistance and thrombosis are common problems. In such cases, we use prasugrel as rescue medication, and we clarified its usefulness.

Methods

We retrospectively investigated 199 consecutive cases of neuroendovascular therapy performed at our hospital from April 2016 to March 2018, and examined the safety and effectiveness of prasugrel.

Results

There were 14 cases of prasugrel administration: six cases of coil embolization for cerebral aneurysm, five cases of carotid artery stenting (CAS), and three other cases.The reasons for prasugrel administration were as follows: emergency stent use in four cases, intraoperative thrombosis in three cases, intra-stent thrombosis after CAS in three cases, and others in four cases. In all cases, it was used in combination with aspirin and the median duration of administration was 212 days. Regarding its safety, there was one hemorrhagic complication at the puncture site for which the involvement of prasugrel was unable to be excluded, but it was improved by conservative treatment and there was no major hemorrhage such as intracranial hemorrhage. Regarding its efficacy, in one case, the thrombus during coil embolization did not completely disappear after prasugrel administration and additional mechanical thrombolysis was required. However, no new thrombosis was observed during prasugrel administration in all 14 cases.

Conclusion

Prasugrel may be useful as a rescue medication in neuroendovascular therapy.

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.

Comparison of Prasugrel and Clopidogrel Used as Antiplatelet Medication for Endovascular Treatment of Unruptured Intracranial Aneurysms: A Meta-Analysis

BACKGROUND

Clopidogrel is routinely used to decrease ischemic complications during neurointerventional procedures. However, the efficacy may be limited by antiplatelet resistance.

PURPOSE

Our aim was to analyze the efficacy of prasugrel compared with clopidogrel in the cerebrovascular field.

DATA SOURCES

A systematic search of 2 large databases was performed for studies published from 2000 to 2018.

STUDY SELECTION

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting treatment-related outcomes of patients undergoing neurointerventional procedures under prasugrel, and studies comparing prasugrel and clopidogrel.

DATA ANALYSIS

Random-effects meta-analysis was used to pool the overall rate of complications, ischemic and hemorrhagic events, and influence of the dose of prasugrel.

DATA SYNTHESIS

In the 7 included studies, 682 and 672 unruptured intracranial aneurysms were treated under prasugrel (cases) and clopidogrel (controls), respectively. Low-dose (20 mg/5 mg; loading and maintenance doses) prasugrel compared with the standard dose of clopidogrel (300 mg/75 mg) showed a significant reduction in the complication rate (OR = 0.36; 95% CI, 0.17-74, P = .006; I² = 0%). Overall, the ischemic complication rate was significantly higher in the clopidogrel group (40/672 = 6%; 95% CI, 3%-13%; I² = 83% versus 16/682 = 2%; 95% CI, 1%-5%; I² = 73%; P = .03). Low and high loading doses of prasugrel were associated with 0.6% (5/535; 95% CI, 0.1%-1.6%; I² = 0%) and 9.3% (13/147; 95% CI, 0.2%-18%; I² = 60%) intraperiprocedural hemorrhages, respectively (P = .001), whereas low and high maintenance doses of prasugrel were associated with 0% (0/433) and 0.9% (2/249; 95% CI, 0.3%-2%; I² = 0%) delayed hemorrhagic events, respectively (P = .001).

LIMITATIONS

Retrospective series and heterogeneous endovascular treatments were limitations.

CONCLUSIONS

In our study, low-dose prasugrel compared with clopidogrel premedication was associated with an effective reduction of the ischemic events with an acceptable rate of hemorrhagic complications.

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.

Efficacy and safety of prasugrel therapy for intracranial aneurysms with endovascular treatment: A meta-analysis

BACKGROUND

Prasugrel as a second generation P2Y12 adenosine diphosphate receptor antagonist which in the cerebral aneurysms with Endovascular treatment have become more emphasized.

OBJECTIVE

To compare the efficacy and safety of prasugrel therapy for intracranial aneurysms with endovascular treatment.

METHODS

The databases of PubMed, Embase, Cochrane Library databases and China Biology Medicine disc were retrieved with computers for collecting controlled trials about the comparison in the efficacy and safety of prasugrel and clopidogrel published from inception to September 2018. At the same time, the reference materials of included literature were retrieved manually. After rigorous evaluation on literature quality, the eligible data of the trials was extracted and given a Meta-analysis by applying RevMan5.3 software.

RESULTS

Of the 96 studies identified, 7 trials were included. Results of meta-analysis showed that compared with patients receiving clopidogrel treatment, novel platelet P2Y₁₂ receptor inhibitor prasugrel were effective in reducing the incidence of thromboembolic events (OR = 0.19, 95%CI: 0.08-0.45, P = .0001), but did not increase the risk of hemorrhagic complication (OR = 1.00, 95%CI: 0.53-1.89, P = 1.00), and the PRU (OR = 0.19, 95%CI: 0.08-0.45, P = .0001) and Percentage inhibition of platelet (MN = 37.05, 95%CI: 33.37-40.73, P < .00001) were controlled in a better range.

CONCLUSION

In antiplatelet therapy after aneurysmal interventional therapy, the second generation of P2Y₁₂ adenosine receptor antagonist prasugrel can significantly reduce the risk of thrombosis without increasing the risk of bleeding.

Low-Dose Prasugrel in Patients with Resistance to Clopidogrel for the Treatment of Cerebral Aneurysms

Thromboembolism is one of the major complications of stent assisted coiling in treatment of cerebral aneurysm. Clopidogrel resistance is so common and prasugrel is more effective in its rapid and potent effect. We investigated changes in the value of P2Y12 resistance unit (PRU) when prasugrel was administered to patients with clopidogrel resistance. One hundred mg of aspirin and 75 mg of clopidogrel were administered for 5 days before the procedure, and PRU were examined. The resistance to clopidogrel was defined as the inhibition of PRU was less than 20%. PRU was re-examined after loading 20 mg of prasugrel. We treated 98 consecutive patients between January 2018 and July 2018, and 24 patients (24.5%) had resistance to clopidogrel. Nineteen patients were female. The mean PRU value at admission was 238.5±36.9 and the percentage inhibition value was 4.8±6.3%. After the use of prasugrel, the mean PRU and percentage inhibition values were measured as 124.9±49.9 and 48.0±19.24, respectively. All patients except one patient had a PRU inhibition value as a responder. There was no hemorrhage or thromboembolic complication during mean 1.5 months follow-up after embolization procedure. In conclusion, in patients resistant to clopidogrel, the low dose prasugrel seems to be effective in keeping the percentage inhibition value of PRU within the normal range in treatment of cerebral aneurysm. Further study will be needed to determine the optimal dose of prasugrel to enhance prevention effect of thromboembolism and to reduce hemorrhagic complications during stent assisted coiling.