ABCD^(2) risk score does not predict the presence of cerebral microemboli in patients with hyper-acute symptomatic critical carotid artery stenosis

Introduction:ABCD^(2) risk score and cerebral microemboli detected by transcranial Doppler(TCD)have been separately shown to the predict risk of recurrent acute stroke.We studied whether ABCD2 risk score predicts cerebral microemboli in patients with hyper-acute symptomatic carotid artery stenosis.Participants and methods:We studied 206 patients presenting within 2 weeks of transient ischaemic attack or minor stroke and found to have critical carotid artery stenosis(≥50% ).86 patients(age 70±1(SEM:years),58 men,83 Caucasian)had evidence of microemboli;72(84% )of these underwent carotid endarterectomy(CEA).120 patients(age 72±1 years,91 men,113 Caucasian)did not have microemboli detected;102(85% )of these underwent CEA.Data were analysed using X2 and Mann–Whitney U tests and receiver operating characteristic(ROC)curves.Results:140/206(68% :95% CI 61.63 to 74.37)patients with hyper-acute symptomatic critical carotid stenosis had an ABCD2 risk score≥4.There was no significant difference in the NICE red flag criterion for early assessment(ABCD^(2) risk score≥4)for patients with cerebral microemboli versus those without microemboli(59/86 vs 81/120 patients:OR 1.05 ABCD2 risk score≥4(95% CI 0.58 to 1.90,p=0.867)).The ABCD2 risk score was<4 in 27 of 86(31% :95% CI 21 to 41)embolising patients and in 39 of 120(31% :95% CI 23 to 39)without cerebral microemboli.After adjusting for pre-neurological event antiplatelet treatment(APT),area under the curve(AUC)of ROC for ABCD2 risk score showed no prediction of cerebral microemboli(no pre-event APT,n=57:AUC 0.45(95% CI 0.29 to 0.60,p=0.531);preevent APT,n=147:AUC 0.51(95% CI 0.42 to 0.60,p=0.804)).Conclusions:The ABCD2 score did not predict the presence of cerebral microemboli or carotid disease in over one-quarter of patients with symptomatic critical carotid artery stenosis.On the basis of NICE guidelines(refer early if ABCD2≥4),assessment of high stroke risk based on ABCD2 scoring may lead to inappropriate delay in urgent treatment in many patients.

Registry report on prediction by Pocock cardiovascular score of cerebral microemboli acutely following carotid endarterectomy

background Cerebral microemboli may lead to ischaemic neurological complications after carotid endarterectomy(CEA).The association between classical cardiovascular risk factors and acute cerebral microemboli following carotid surgery has not been studied.The aim of this study was to explore whether an established cardiovascular risk score(Pocock score)predicts the presence of cerebral microemboli acutely after CEA.subjects and methods Pocock scores were assessed for the 670 patients from the Carotid Surgery Registry(age 71±1(SEM)years,474(71%)male,652(97%)Caucasian)managed from January 2002 to December 2012 in the Regional Vascular Centre at University Hospitals Coventry and Warwickshire NHS Trust,which serves a population of 950000.CEA was undertaken in 474(71%)patients for symptomatic carotid stenosis and in 196(25%)asymptomatic patients during the same period.74% of patients were hypertensive,71%were smokers and 49% had hypercholesterolaemia.results A high Pocock score(≥2.3%)was significantly associated with evidence of cerebral microemboli acutely following CEA(P=0.039,Mann-Whitney(MW)test).A Pocock score(≥2.3%)did not predict patients who required additional antiplatelet therapy(microemboli signal(MES)rate>50 hour-1:P=0.164,MW test).Receiver operating characteristic analysis also showed that the Pocock score predicts acute postoperative microemboli(area under the curve(AUC)0.546,95%CI 0.502 to 0.590,P=0.039)but not a high rate of postoperative microemboli(MES>50 hour−1:AUC 0.546,95% CI 0.482 to 0.610,P=0.164).A Pocock score≥2.3% showed a sensitivity of 74% for the presence of acute postoperative cerebral microemboli.A Pocock score≥2.3% also showed a sensitivity of 77% and a negative predictive value of 90% for patients who developed a high microembolic rate>50 hour−1 after carotid surgery.Conclusion These findings demonstrate that the Pocock score could be used as a clinical tool to identify patients at high risk of developing acute postoperative microemboli.