Omeprazole-clopidogrel interaction and neurovascular complications after flow-diverter device placement

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of Tirofiban to Prevent Ischemic Events in Patients with CYP2C19 Loss-of-Function Alleles during Flow Diversion of Intracranial Aneurysm: A Multicenter Cohort Study

To analyze the effect of tirofiban on ischemic events in CYP2C19 loss-of-function (LOF) allele carriers during pipeline embolization device (PED) implantation. Demographic information, imaging data, ischemic complications, CYP2C19 genotyping, and platelet function test results were collected from patients with PED-treated intracranial aneurysms at three centers. Multivariate logistic regression was used to analyze risk factors for ischemic events. Patients were grouped according to LOF alleles and antiplatelet drugs, the baseline information of LOF allele carriers and non-carriers were compared, and the efficacy of tirofiban was analyzed by comparing the incidence of ischemic events in each group. In total, 278 patients were included in the study, 24 of whom had an ischemic event. 157 (56.5%) patients carried the LOF allele and were more likely to develop resistance to clopidogrel (P < 0.001) and hypertension (P = 0.010). Multivariate logistic regression analysis revealed that the independent risk factors for ischemic events were age of > 55 years (OR = 3.308, P = 0.028), LOF alleles (OR = 3.960, P = 0.036), and clopidogrel nonresponsiveness (OR = 3.301, P = 0.014). For LOF allele carriers, prophylactic use of tirofiban after PED implantation helped to reduce ischemic events (4.3% vs. 16.4%, P = 0.039). This study supports CYP2C19 genotyping before flow diversion because LOF alleles increase the risk of ischemic events. Prophylactic use of tirofiban may help reduce ischemic events in LOF allele carriers.

Long-term Follow-up Results after Flow Diverter Therapy Using the Pipeline Embolization Device for Large or Giant Unruptured Internal Carotid Artery Aneurysms: Single-center Retrospective Analysis in the Japanese Population

Flow diverter (FD) therapy using Pipeline embolization device (PED) has become an important alternative to treat internal carotid artery (ICA) aneurysms. Herein, we report the long-term outcome for 3 years after FD therapy using PED for ICA aneurysms in Japan. The patients who underwent angiographical and/or clinical follow-up for 3 years after the FD therapy using PED of large or giant unruptured ICA aneurysms from December 2012 at our university hospital are the subjects of this study. We retrospectively reviewed the in- and outpatients’ medical charts, and written operative and radiological records. There were 84 patients with 90 aneurysms who could be clinically and/or angiographically followed up for 3 years. Of these, 7 aneurysms were only available for clinical follow-up. Of the remaining 83 aneurysms, 6 aneurysms had vessel occlusion due to stent thrombosis or parent artery occlusion, and 60 of the remaining 77 (77.9%) had complete occlusion. In multivariate analysis, older age (>70 years), wide neck, and non-adjunctive coiling contributed statistically significantly to incomplete occlusion. Of the 84 patients, 2 patients (2.4%) had delayed complications between 6 months and 3 years after the initial FD placement. Three patients (3.6%) had poor outcome due to postoperative major stroke complications, 2 of which were acute complications. The long-term results after FD therapy are good both angiographically and clinically. Endothelialization of the aneurysmal neck and intra-aneurysmal thrombosis contribute to complete occlusion. The primary reason for the somewhat low complete occlusion in Japan may be the patients are generally older.