Measurement of antiplatelet inhibition during neurointerventional procedures: the effect of antithrombotic duration and loading dose.
ABSTRACT Symptomatic thromboembolic events are the most common complications associated with aneurysm coiling, and carotid and intracranial stenting. Our objective is to assess the effect of aspirin (ASA) and clopidogrel dose and duration on platelet inhibition using a point of care assay in neurointerventional (NI) suite.
The dose, duration, and point of care platelet function assay data for clopidogrel and aspirin therapy were prospectively collected between February 2006 and November 2007. Inadequate platelet inhibition for ASA was defined as >or=550 ASA reaction units (ARU), and for clopidogrel was defined as <or=50% inhibition of the P2Y12/ADP receptor
We collected data from 216 consecutive patients. Inadequate platelet inhibition was noted in 13% of patients on aspirin and 66% of patients on clopidogrel (P-value < .0001). Patients taking clopidogrel 75 mg for >or=7 days, 300 mg for 24 hours, and 600 mg same day load had a mean P2Y12/ADP inhibition of 45%, 35% (P-value = .09), and 16%, respectively (P-value = .005).
Premedication with clopidogrel, in contrast to aspirin, does not achieve adequate platelet inhibition in about two-third of the patients. Same day antiplatelet loading may be insufficient to achieve adequate platelet inhibition and should be avoided if clinically feasible.
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ABSTRACT: Background: Antiplatelet agents have an important role in the prevention of ischemic complications during endovascular treatment. The aim of this study was to identify correlations between the clinical outcomes of neurointervention. This study also aimed to determine the optimal cutoff for P2Y12 percent inhibition to prevent ischemic and bleeding complications and to confirm the accuracy of the cutoff value. Methods: A prospective study was conducted for all patients (n = 66) who received antiplatelet therapy during neurointervention at Toyama University Hospital during a 25-month period. Platelet reactivity was measured before the procedure using the VerifyNow and filter pressure methods. The primary outcome was the 30-day incidence of adverse clinical events, defined as ischemic or bleeding events, in relation to P2Y12 percent inhibition distribution. Results: Multivariate analysis showed that P2Y12 percent inhibition was an independent predictor for bleeding (P = .021, odds ratio [OR] = 3.45; 95% confidence interval [CI], 2.31-4.88) and ischemic (P = .045, OR = 3.63; 95% CI, 2.11-7.12) events. In receiver operating characteristic curve analysis, P2Y12 percent inhibition could significantly discriminate between patients with and without bleeding and ischemic events. The optimal cutoffs for bleeding (74%) and ischemic events (26%) were used to define 3 groups: those with poor response, sufficient response, and hyper-response. Ischemic and bleeding complications were significantly different among the 3 groups. Conclusions: Optimal threshold, measured using the VerifyNow P2Y12 assay, can be identified using specific thresholds (26% < percent inhibition < 74%) to define patients at lower risk for ischemic and bleeding events. The threshold for hyper-response can highly predict bleeding events in perioperative period. On the other hands, cutoff value for poor response may be affected by various factors.Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 06/2014; 23(7). DOI:10.1016/j.jstrokecerebrovasdis.2014.04.014 · 1.99 Impact Factor
Journal of Neurointerventional Surgery 07/2014; 4(8). DOI:10.1136/neurintsurg-2014-011357 · 2.50 Impact Factor
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ABSTRACT: INTRODUCTION: The measurement of platelet inhibition (PI) level may be useful in quantifying the risk of thromboembolic complication in subjects undergoing endovascular treatment using implantable materials. We studied the predictability of the VerifyNow point-of-care assay in a large sample of consecutive neurointerventional procedures. METHODS: The percentage of P2Y12-inhibition was systematically measured in a total of 271 procedures (245 patients). The incidence of poor response and adverse events within the first 48 hours were recorded. RESULTS: The overall occurrence of poor response after a single loading-dose of clopidogrel of 300 mg was 61.3 % using a cut-off of 40 % and 43.9 % using a cut-off of 20 %. In the analysis of the incidence of adverse events by P2Y12-inhibition grouping, a significant association was observed between thromboembolic events and low response, with an overall incidence of 10.2 % (cut-off of 40 %) and 11.8 % (cut-off of 20 %). The assessment of predictability using different cut-offs showed that more than 90 % of thromboembolic events would be in the group of poor responders using a 40 % cut-off and more than 75 % using 20 %. CONCLUSION: The use of the VerifyNow assay in the neurointerventional context seems a valuable tool in the early detection of individuals at risk of peri-operative thromboembolic adverse events.