Cangrelor and Stenting in Acute Ischemic Stroke : Monocentric Case Series

Cangrelor for neurointerventional procedures: A systematic review

Thromboembolism is a complication of neurointerventional procedures that requires patients to be placed under antiplatelet therapy. Current options for antiplatelet therapies have a delayed onset of action that prevents a rapid door to puncture transition for patents presenting in acute settings. Cangrelor (Kengreal, Chiesi, USA) is an intravenous P2Y12 platelet inhibitor approved in percutaneous coronary interventions that has an immediate onset of action and half-life between 2 and 6 min. Thus, the goal of this study is to report on the safety, effectiveness, and indications for using Cangrelor in neurointerventional procedures. A systematic review of studies describing the use of Cangrelor in neurointervention was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search was conducted on PubMed, Ovid Medline, and Embase databases through June 2023. Seventeen studies with 314 patients met inclusion criteria. The most common indication for Cangrelor use was acute ischemic strokes: 70% followed by aneurysms 27.4%. The Infusion protocol varied from 5 to 30 μg/kg bolus and 1 to 4 µg/kg/min infusion with 30 μg/kg bolus and 4 µg/kg/min infusion being reported in 64.7% of studies. Intra-operative platelet reacting unit levels were below 200 in all the studies that reported it, and the percentage of hemorrhagic, thromboembolic, and deaths occurrence in this patient cohort was respectively 11.1%, 4.8%, and 8.6%. Cangrelor appears to be a promising P2Y12 platelet inhibitor for neurointerventional procedures. However, large, randomized trials are needed to determine the full range of its effects in neurointerventional procedures.

Immunothrombosis versus thrombo-inflammation: platelets in cerebrovascular complications

A State-of-the Art lecture titled "Thrombo-Neuroinflammatory Disease" was presented at the International Society on Thrombosis and Haemostasis Congress in 2023. First, we would like to advocate for discrimination between immunothrombosis and thrombo-inflammation, as immunothrombosis describes an overshooting inflammatory reaction that results in detrimental thrombotic activity. In contrast, thrombo-inflammation describes the interplay of platelets and coagulation with the immunovascular system, resulting in the recruitment of immune cells and loss of barrier function (hence, hallmarks of inflammation). Both processes can be observed in the brain, with cerebral venous thrombosis being a prime example of immunothrombosis, while infarct progression in response to ischemic stroke is a paradigmatic example of thrombo-inflammation. Here, we review the pathomechanisms underlying cerebral venous thrombosis and ischemic stroke from a platelet-centric perspective and discuss translational implications. Finally, we summarize relevant new data on this topic presented during the 2023 International Society on Thrombosis and Haemostasis Congress.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Intravenous cangrelor use for neuroendovascular procedures: a two-center experience and updated systematic review

Background

The optimal antiplatelet therapy regimen for certain neuroendovascular procedures remains unclear. This study investigates the safety and feasibility of intravenous dose-adjusted cangrelor in patients undergoing acute neuroendovascular interventions.

Methods

We conducted a retrospective chart review of all consecutive patients on intravenous cangrelor for neuroendovascular procedures between September 1, 2020, and March 13, 2022. We also conducted an updated systematic review and meta-analysis using PubMed, Scopus, Web of Science, Embase and the Cochrane Library up to February 22, 2023.

Results

In our cohort, a total of 76 patients were included [mean age (years): 57.2 ± 18.2, males: 39 (51.3), Black: 49 (64.5)]. Cangrelor was most used for embolization and intracranial stent placement (n = 24, 32%). Approximately 44% of our patients had a favorable outcome with a modified Rankin Scale (mRS) score of 0 to 2 at 90 days (n = 25/57); within 1 year, 8% of patients had recurrent or new strokes (n = 5/59), 6% had symptomatic intracranial hemorrhage [sICH] (4/64), 3% had major extracranial bleeding events (2/64), and 3% had a gastrointestinal bleed (2/64). In our meta-analysis, 11 studies with 298 patients were included. The pooled proportion of sICH and intraprocedural thromboembolic complication events were 0.07 [95% CI 0.04 to 1.13] and 0.08 [95% CI 0.05 to 0.15], respectively.

Conclusion

Our study found that intravenous cangrelor appears to be safe and effective in neuroendovascular procedures, with low rates of bleeding and ischemic events. However, further research is needed to compare different dosing and titration protocols of cangrelor and other intravenous agents.

Emergent use of ticagrelor during endovascular reperfusion in large arterial occlusions

OBJECTIVE

Given many emerging indications for endovascular interventions in ischemic strokes, a safe and effective adjuvant antiplatelet regimen for acute revascularization has become a subject of interest. Ticagrelor is a direct oral P2Y12 inhibitor that may achieve rapid platelet suppression than standard oral therapies. We report our experience of Ticagrelor use in revascularization of acute large arterial steno-occlusive disease, describing procedural post-procedure thrombotic events, major hemorrhages, and other clinical outcomes.

METHODS

This was a single-center retrospective case series of large steno-occlusive disease requiring endovascular reperfusion with emergent adjuvant Ticagrelor, defined as 30 min of the procedure from skin puncture to closure of the arteriotomy. Major outcomes investigated were thromboembolism in the target artery, and symptomatic intracranial or extracranial major hemorrhages. Additional analyses were performed with respect to timing of the administration and use of rescue GPIIb/IIIa inhibitors if any.

RESULTS

73 consecutive patients were identified, presenting with severe ischemic stroke (median NIHSS 16) of large artery origin. 67% required stent placement (45% cervical carotid, 22% intracranial artery), 9.5% angioplasty and 23% mechanical thrombectomy only. Two experienced symptomatic in-stent occlusion, and 7 experienced major hemorrhages (9.5%) including 3 fatal symptomatic intracranial hemorrhages (4.1%). Among 19 subjects (26%) who received pretreatment with Ticagrelor, there were fewer GPIIb/IIIa administration, angioplasty and stenting, without yielding benefit in functional outcome or mortality. GPIIb/IIIa was administered as rescue therapy in 45 subjects (62%), which was found associated with increased bleeding compared to patients receiving Ticagrelor only, in whom no bleeding complications were recorded (16% vs. 0%; p = 0.03).

CONCLUSION

We report our findings on Ticagrelor as an adjuvant antiplatelet therapy in ischemic stroke of large arterial origin requiring emergent revascularization. Effectiveness, safety, need for additional rescue treatment, and comparison to other commonly used oral antiplatelets should be investigated in future prospective studies.

Low dose intravenous cangrelor versus glycoprotein IIb/IIIa inhibitors in endovascular treatment of tandem lesions

OBJECTIVES

Intravenous (IV) periprocedural antiplatelet therapy (APT) for patients undergoing acute carotid stenting during mechanical thrombectomy (MT) is not fully investigated. We aimed to compare the safety profile of IV low dose cangrelor versus IV glycoprotein IIb/IIIa (GP-IIb/IIIa) inhibitors in patients with acute tandem lesions (TLs).

MATERIALS AND METHODS

We retrospectively identified all cases of periprocedural administration of IV cangrelor or GP-IIb/IIIa inhibitors during acute TLs intervention from a multicenter collaboration. Patients were divided in two groups according to the IV APT regimen at the time of MT procedure: 1) cangrelor and 2) GP-IIb/IIIa inhibitors (tirofiban and eptifibatide). Safety outcomes included rates of symptomatic intracranial hemorrhage (sICH), parenchymal hematoma type 1 and 2 (PH1-PH2), and hemorrhagic infarction type 1 and 2 (HI1-HI2).

RESULTS

Sixty-three patients received IV APT during MT, 30 were in the cangrelor group, and 33 were in the GP-IIb/IIIa inhibitors group. There were no significant differences in the rates of sICH (3.3% vs. 12.1%, aOR=0.21, 95%CI 0.02-2.18, p=0.229), HI1-HI2 (21.4% vs 42.4%, aOR=0.21, 95%CI 0.02-2.18, p=0.229), and PH1-PH2 (17.9% vs. 12.1%, aOR=1.63, 95%CI 0.29-9.83, p=0.577) between both treatment groups. However, there was a trend toward reduced hemorrhage rates with cangrelor. Cangrelor was associated with increased odds of complete reperfusion (aOR=5.86; 95%CI 1.57-26.62;p=0.013).

CONCLUSIONS

In this retrospective non-randomized cohort study, our findings suggest that low dose cangrelor has similar safety and increased rate of complete reperfusion compared to IV GP-IIb/IIIa inhibitors. Further prospective studies are warranted to confirm this association.

Antiplatelet Therapy in Neurointervention

The aim of this review is to provide an overview of the use of antiplatelet medication in neurointervention, with a focus on the clinical indications for antiplatelet use in both preventing and reducing platelet aggregation. This review will cover current antiplatelet medications, pharmacokinetics, and pharmacodynamics. We will provide an overview of different endovascular devices and discuss the antiplatelet regimes in neurointervention, highlighting gaps in evidence and scope for future studies.Two randomized controlled trials have evaluated antiplatelet use in the setting of acute large vessel occlusion stroke, with neither demonstrating benefit in their overall cohorts. Evidence on antiplatelet medication for both acute and elective stenting for acute stroke and treatment of cerebral aneurysms is currently based on large case series, and practice in neurointervention has increasingly utilized dual antiplatelet regimes with clopidogrel and second-line agents like prasugrel and ticagrelor. Clopidogrel function testing has an increasing role in neurointerventional procedures, particularly for high metal surface area stents such as the braided flow diverter type stents. Intravenous glycoprotein IIB/IIIA inhibitors have been utilized for both acute bridging and rescue therapy.Antiplatelet decision making is complex, and there are few randomized control trials to guide clinical practice. Comparative trials to guide decision making remain important in both the acute and elective settings. Standardised protocols incorporating platelet function testing may play a role in assisting decision making until more robust clinical evidence is available, particularly in the context of acute neurointerventional stenting for stroke and ruptured cerebral aneurysms.

Anaesthetic and peri-operative management for thrombectomy procedures in stroke patients

PURPOSE

To provide recommendations for the anaesthetic and peri-operative management for thrombectomy procedure in stroke patients DESIGN: A consensus committee of 15 experts issued from the French Society of Anaesthesia and Intensive Care Medicine (Société Française d'Anesthésie et Réanimation, SFAR), the Association of French-language Neuro-Anaesthetists (Association des Neuro-Anesthésistes Réanimateurs de Langue Francaise, ANARLF), the French Neuro-Vascular Society (Société Francaise de Neuro-Vasculaire, SFNV), the French Neuro-Radiology Society (Société Francaise de Neuro-Radiologie, SFNR) and the French Study Group on Haemostasis and Thrombosis (Groupe Français d'Études sur l'Hémostase et la Thrombose, GFHT) was convened, under the supervision of two expert coordinators from the SFAR and the ANARLF. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guideline elaboration process was conducted independently of any industry funding. The authors were required to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide their assessment of quality of evidence.

METHODS

Four fields were defined prior to the literature search: (1) Peri-procedural management, (2) Prevention and management of secondary brain injuries, (3) Management of antiplatelet and anticoagulant treatments, (4) Post-procedural management and orientation of the patient. Questions were formulated using the PICO format (Population, Intervention, Comparison, and Outcomes) and updated as needed. Analysis of the literature was then conducted and the recommendations were formulated according to the GRADE methodology.

RESULTS

The SFAR/ANARLF/SFNV/SFNR/GFHT guideline panel drew up 18 recommendations regarding anaesthetic management of mechanical thrombectomy procedures. Due to a lack of data in the literature allowing to conclude with high certainty on relevant clinical outcomes, the experts decided to formulate these guidelines as "Professional Practice Recommendations" (PPR) rather than "Formalized Expert Recommendations". After two rounds of rating and several amendments, a strong agreement was reached on 100% of the recommendations. No recommendation could be formulated for two questions.

CONCLUSIONS

Strong agreement among experts was reached to provide a sizable number of recommendations aimed at optimising anaesthetic management for thrombectomy in patients suffering from stroke.

24-Hour Carotid Stent Patency and Outcomes After Endovascular Therapy: A Multicenter Study

BACKGROUND

Management of extracranial internal carotid artery steno-occlusive lesion during endovascular therapy remains debated. Stent occlusion within 24 hours of endovascular therapy is a frequent event after acute carotid artery stenting, and we currently lack large population results. We investigated the incidence, predictors, and clinical impact of stent occlusion after acute carotid artery stenting in current clinical practice.

METHODS

Patients treated by endovascular therapy with acute carotid artery stenting between 2015 and 2019 in 5 large-volume endovascular-capable centers were retrospectively analyzed. Patients were separated in 2 groups according to the stent patency at 24 hours after carotid artery stenting. We compared baseline characteristics, treatment modalities, and clinical outcome depending on 24-hour stent patency. Primary end point was favorable outcome, defined as a modified Rankin Scale score 0-2 at 3 months.

RESULTS

A stent occlusion was observed in 47/225 patients (20.9%). Patients with stent patency had a lower baseline National Institutes of Health Stroke Scale (median [interquartile range]: 13 [7-17] versus 18 [12-21]) and had more often stroke of atherothrombotic origin (77.0% versus 53.2%). A higher stent patency rate was found for patients treated with P2Y₁₂ antagonists at the acute phase (odds ratio [OR]' 2.95 [95% CI' 1.10-7.91]; P=0.026) and treated with angioplasty (OR' 2.42 [95% CI' 1.24-4.67]; P=0.008). A better intracranial angiographic reperfusion was observed in patients with 24-hour stent patency compared with patients without stent patency (OR' 8.38 [95% CI' 3.07-22.78]; P<0.001). Patients with a stent patency at 24 hours had a higher chance of favorable outcome (OR' 3.29 [95% CI, 1.66-6.52]; P<0.001) and a lower risk of death (OR' 0.32 [95% CI, 0.13-0.76]; P=0.009).

CONCLUSIONS

One out of 5 patients treated with carotid artery stenting during endovascular therapy presented a stent occlusion within 24 hours. This event was associated with worse functional outcome. Stroke etiology, P2Y₁₂ antagonist administration, quality of intracranial reperfusion, and angioplasty were associated with 24-hour stent patency.

Long-Term Cangrelor Administration in Neurology Intensive Care: A Case Series

Cangrelor is a P2Y12 inhibitor antiplatelet agent, with a rapid onset and offset. The available literature only reviews short-term administration over a few hours. We describe 5 patients who received cangrelor for >1 month in a neurosurgical intensive care unit due to a very high likelihood of requiring emergency revision surgery. Despite multiple therapeutic interruptions for surgical procedures, no hemorrhagic events occurred, and there was only one transient ischemic event, which occurred during transition from cangrelor to ticagrelor. Cangrelor can be a therapeutic option for patients with a high likelihood of requiring revision neurosurgery after intracranial stenting.

Use of intravenous cangrelor in the treatment of ruptured and unruptured cerebral aneurysms: an updated single-center analysis and pooled analysis of current studies

BACKGROUND

Intracranial stent placement for the treatment of cerebral aneurysms is increasingly utilized in both ruptured and unruptured scenarios. Intravenous (IV) cangrelor is a relatively new antiplatelet agent that was initially approved for coronary interventions. In addition to our institution, five other centers have published their results using IV cangrelor in neurointerventional procedures. This article combines the aneurysm treatment data from all prior studies to provide insight into the safety and efficacy of cangrelor for intracranial aneurysm treatment.

METHODS

A prospectively maintained database was reviewed to identify all cases of IV cangrelor administration during aneurysm embolization. 20 additional patients were identified who had not been previously published. In addition, a literature search was performed to identify prior publications regarding cangrelor in neurointervention. The data from these were combined with our institutional results in a pooled-analysis.

RESULTS

Overall, 85 patients who received IV cangrelor during aneurysm embolization were identified, including 46 ruptured and 39 unruptured cases. The asymptomatic and symptomatic intracranial hemorrhage rates were 4% (2/46) for ruptured cases and 2.6% (1/39) for unruptured cases. The rate of retroperitoneal hematoma and gastrointestinal bleeding was 0%. There were no incidents of intraprocedural thromboembolic complication or intraprocedural in-stent thrombosis in either cohort. One subject suffered an ischemic stroke at 24 hours secondary to in-stent thrombosis in a ruptured case.

CONCLUSIONS

IV cangrelor during aneurysm embolization appears to be safe, with a symptomatic intracranial hemorrhage rate of 4% in ruptured cases and 2.6% in unruptured cases. More research is needed to determine the ideal dosing regimen.

Safety and Efficacy of Cangrelor in Acute Stroke Treated with Mechanical Thrombectomy: Endovascular Treatment of Ischemic Stroke Registry and Meta-analysis

BACKGROUND AND PURPOSE

Rescue therapies are increasingly used in the setting of endovascular therapy for large-vessel occlusion strokes. Among these, cangrelor, a new P2Y12 inhibitor, offers promising pharmacologic properties to join the reperfusion strategies in acute stroke. We assessed the safety and efficacy profiles of cangrelor combined with endovascular therapy in patients with large-vessel-occlusion stroke.

MATERIALS AND METHODS

We performed a retrospective patient data analysis in the ongoing prospective multicenter observational Endovascular Treatment in Ischemic Stroke Registry in France from July 2018 to December 2020 and conducted a systematic review and meta-analysis using several data bases. Indications for cangrelor administration were rescue strategy in case of refractory intracranial occlusion with or without intracranial rescue stent placement, and cervical carotid artery stent placement in case of cervical occlusion (tandem occlusion or isolated cervical carotid occlusion).

RESULTS

In the clinical registry, 44 patients were included (median initial NIHSS score, 12; prior intravenous thrombolysis, 29.5%). Intracranial stent placement was performed in 54.5% (n = 24/44), and cervical stent placement, in 27.3% (n = 12/44). Adjunctive aspirin and heparin were administered in 75% (n = 33/44) and 40.9% (n = 18/44), respectively. Rates of symptomatic intracerebral hemorrhage, parenchymal hematoma, and 90-day mortality were 9.5% (n = 4/42), 9.5% (n = 4/42), and 24.4% (n = 10/41). Favorable outcome (90-day mRS, 0-2) was reached in 51.2% (n = 21/41), and successful reperfusion, in 90.9% (n = 40/44). The literature search identified 6 studies involving a total of 171 subjects. In the meta-analysis, including our series data, symptomatic intracerebral hemorrhage occurred in 8.6% of patients (95% CI, 5.0%-14.3%) and favorable outcome was reached in 47.6% of patients (95% CI, 27.4%-68.7%). The 90-day mortality rate was 22.6% (95% CI, 13.6%-35.2%). Day 1 artery patency was observed in 89.7% (95% CI, 81.4%-94.6%).

CONCLUSIONS

Cangrelor offers promising safety and efficacy profiles, especially considering the complex endovascular reperfusion procedures in which it is usually applied. Further large prospective data are required to confirm these findings.

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

STUDY OBJECTIVES

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

DESIGN

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

PATIENTS

Neuroendovascular patients treated with cangrelor.

SETTING

Albany Medical Center Hospital.

INTERVENTION AND MAIN RESULTS

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

CONCLUSIONS

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

A Multicenter Preliminary Study of Cangrelor following Thrombectomy Failure for Refractory Proximal Intracranial Occlusions

BACKGROUND AND PURPOSE

Rescue endovascular and pharmacologic approaches are increasingly being adopted after recanalization failure of acute large-vessel occlusion strokes with mechanical thrombectomy, with encouraging results. The safety and efficacy of glycoprotein IIb/IIIa inhibitors in ischemic stroke have been investigated, though cangrelor, a recent intravenous P2Y12-receptor inhibitor with a rapid onset/offset of action and a short half-life, may be a valuable option. We compared the safety and efficacy of cangrelor with those of glycoprotein IIb/IIIa inhibitors for refractory occlusions.

MATERIALS AND METHODS

We performed a retrospective analysis of the ongoing prospective, multicenter, observational Endovascular Treatment in Ischemic Stroke Registry in France between May 2012 and February 2020. Refractory intracranial occlusions of the anterior and posterior circulation were included and defined as recanalization failure of large-vessel occlusion stroke, perioperative target artery reocclusion, or high risk of early reocclusion related to an arterial wall lesion. The primary end point was a favorable outcome, defined as a 90-day mRS of 0-2. Secondary end points were reperfusion, intracranial hemorrhage, and procedural complications.

RESULTS

Among 69 patients, 15 were treated with cangrelor, and 54, with glycoprotein IIb/IIIa inhibitors. The favorable outcome (adjusted OR = 2.22; 95% CI, 0.42-11.75; P = .348) and mortality (adjusted OR = 0.44; 95% CI, 0.06-3.16; P = .411) rates were similar in both groups. There was no difference in the rates of any intracranial hemorrhage (adjusted OR = 0.40; 95% CI, 0.08-2.09; P = .280), symptomatic intracranial hemorrhage (6.7% versus 0.0%, P = .058), or procedural complications (6.7% versus 20.4%, P = .215). Reperfusion rates were higher in the cangrelor group, though the difference did not reach statistical significance (93.3% versus 75.0% for modified TICI 2b-3; adjusted OR =10.88; 95% CI, 0.96-123.84; P = .054).

CONCLUSIONS

Cangrelor seems to be as safe as glycoprotein IIb/IIIa inhibitors for managing refractory intracranial occlusion and leads to satisfactory brain reperfusion. Cangrelor is a promising agent in this setting, and additional studies are warranted to confirm our findings.

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

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

Safety of Low Dose Intravenous Cangrelor in Acute Ischemic Stroke: A Case Series

Background: Neurointerventional procedures in acute ischemic stroke often require immediate antiplatelet therapy in the cases of acute stenting and occasionally re-occluding vessels. Intravenous cangrelor is a P2Y12 receptor antagonist with short onset and quick offset. The study objective was to evaluate the safety and efficacy of intravenous cangrelor in patients with acute ischemic stroke requiring urgent antiplatelet effect.

Methods: Patients who received intravenous cangrelor intra-procedurally during acute ischemic stroke treatment were identified from a prospectively collected database. Cangrelor was administered as a bolus of 15 mcg/kg, followed by an infusion rate of 2 mcg/kg/min. A historical control group consisting of anterior circulation tandem occlusions was used to compare to patients with similar lesions who received intravenous cangrelor. Outcomes of interest included in-stent thrombosis, thromboembolic complications, intracranial hemorrhage, and functional outcomes at 90 days.

Results: Twelve patients received intravenous cangrelor for acute ischemic stroke between October 2018 and April 2020 at a comprehensive stroke center. Eleven patients had intra or extracranial stenting performed, which included two posterior circulation lesions. No cases of symptomatic intracranial hemorrhage were reported. At 90 day follow-up, two patients had died and 10 had a good functional outcome. Patients with anterior circulation tandem occlusions who received cangrelor and those who received dual antiplatelets orally had similar radiographic and clinical outcomes.

Conclusion: Low dose intravenous cangrelor is similar in safety and efficacy to oral antiplatelets in acute ischemic stroke in a small case series. Larger prospective studies on the efficacy, safety, and effect on procedure times of intravenous cangrelor in neurointervention are warranted.

Antithrombotic Therapy for Secondary Prevention in Patients with Non-Cardioembolic Stroke or Transient Ischemic Attack: A Systematic Review

Stroke embodies one of the leading causes of death and disability worldwide. We aimed to provide a comprehensive insight into the effectiveness and safety of antiplatelet agents and anticoagulants in the secondary prevention of ischemic stroke or transient ischemic attack. A systematic search for randomized controlled trials, comparing antiplatelet or anticoagulant therapy versus aspirin or placebo among patients with ischemic stroke or transient ischemic attack, was performed in order to summarize data regarding the different regimens. Keyword-based searches in the MEDLINE, EMBASE, and Cochrane Library databases were conducted until the 1st of January 2021. Our search explored 46 randomized controlled trials involving ten antiplatelet agents, six combinations with aspirin, and four anticoagulant therapies. The review of the literature reflects that antiplatelet therapy improves outcome in patients with ischemic stroke or transient ischemic attack. Monotherapy proved to be an effective and safe choice, especially in patients with a high risk of bleeding. Intensified antiplatelet regimens further improve stroke recurrence; however, bleeding rate increases while mortality remains unaffected. Supplementing the clinical judgment of stroke treatment, assessment of bleeding risk is warranted to identify patients with the highest benefit of treatment intensification.

The use of cangrelor in neurovascular interventions: a multicenter experience

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of Cangrelor in Cervical and Intracranial Stenting for the Treatment of Acute Ischemic Stroke: A "Real Life" Single-Center Experience

BACKGROUND AND PURPOSE

In cases of large-vessel-occlusion strokes due to an underlying tandem internal carotid artery occlusion or intracranial atherosclerotic disease, concomitant stent placement may be needed. Immediate platelet inhibition is necessary, but to date, a standardized approach for antiplatelet inhibition in acute settings is still missing. Here we report our single-center experience about the safety and efficacy of periprocedural administration of cangrelor in patients with acute ischemic stroke due to intracranial or cervical artery occlusion undergoing stent placement.

MATERIALS AND METHODS

We retrospectively evaluated all cases of acute ischemic stroke that needed acute stent implantation and were treated with periprocedural administration of cangrelor between January 2019 and April 2020 at our institution. All patients who needed either extracranial or intracranial artery stent placement (in either the anterior or posterior circulation) were included.

RESULTS

We evaluated 38 patients in whom cangrelor was administered IV periprocedurally. Their mean age was 64 years (range, 26-85 years), with 25/38 male subjects and 13/38 female patients. In 26 patients (68.4%), a tandem occlusion was present and was treated with carotid artery stent placement, while 12 patients (31.6%) required an intracranial stent implantation. In 4 subjects (10.5%), an intracerebral hemorrhage occurred after the procedure. All patients in the series were alive 1 week after the procedure.

CONCLUSIONS

Although larger, multicentric randomized studies are strongly warranted, our results support the hypothesis of a possible role of cangrelor as a valuable therapeutic option in the management of platelet inhibition in acute ischemic stroke procedures after intra- or extracranial stent placement.

Cangrelor dose titration using platelet function testing during cerebrovascular stent placement

BACKGROUND

Optimal antiplatelet inhibition is vital during cerebrovascular stenting procedures, yet no standardized recommendation exists for antithrombotic therapy in these scenarios. Cangrelor is an intravenous P2Y12 inhibitor with a favorable pharmacokinetic profile for use during neuroendovascular stenting.

METHODS

A retrospective review of all neuroendovascular patients who underwent stenting between 1 January 2019 and 22 March 2020 and were treated with cangrelor was conducted. Thirty-seven patients met inclusion criteria.

RESULTS

All patients were administered a bolus of 5 mcg/kg of cangrelor followed by a maintenance infusion. Antiplatelet effects of cangrelor were monitored using platelet reactivity units (PRU). Based on the initial PRU, seven patients' doses were adjusted with subsequent PRUs in or near the goal range of 50-150. One patient experienced an acute intraprocedural occlusion likely related to a subtherapeutic PRU which subsequently resolved with cangrelor dose adjustment and intra-arterial tirofiban administration, and one patient experienced a post-procedure stent occlusion which required a thrombectomy and intra-arterial tirofiban administration. No hemorrhagic complications occurred.

DISCUSSION

Cangrelor utilization during neuroendovascular stenting with maintenance doses of <2 mcg/kg/min with dose adjustments based on platelet function testing has not been previously described. Cangrelor presents many advantages compared to standard therapy in patients undergoing stent placement related to its pharmacokinetic profile, rapid onset of action, ease of transition to oral P2Y₁₂ antiplatelet agents, and measurability.

CONCLUSION

Cangrelor is a promising alternative to currently available therapies, especially in patients with a high hemorrhagic risk.