Clinical Outcomes Using a Platelet Function-Guided Approach for Secondary Prevention in Patients With Ischemic Stroke or Transient Ischemic Attack

Abstract

Population-Based Study of Capsular Warning Syndrome and Prognosis After Early Recurrent TIA Paul NN, Sinoni M, Schandratheva A, et al. Neurology 2012:79:1356 Conclusions: Capsular warning syndrome comprises 1.5% of transient ischemic attack (TIA) presentations but has a poor prognosis, with a 7-day stroke risk of 60%. With the exception of capsular warning syndrome, recurrent TIAs Յ7 days are not associated with a greater stroke risk than a single TIA.Summary: Stroke risk after TIA is highest within the first 7 days (Hill MD et al, Neurology 2004;62:2015-20). In addition, many guidelines recommend urgent evaluation for carotid stenosis for patients with more than two TIAs Յ7 days (Johnston SC et al, Ann Neurology 2006;60:301-13). Capsular warning syndrome, manifested by multiple stereotype motor TIAs, is thought to place patients at particular risk and precedes capsular infarction (Donnan GA et al, Neurology 1993;43:957-62). However, it is unclear whether patients with multiple TIAs have relatively untreatable or treatable underlying pathologic conditions such as carotid stenosis or atrial fibrillation. The authors used data from the Oxford Vascular Study (OXVASC) to delineate whether patients with multiple TIAs are at high early stroke risk and whether a treatable underlying condition is more common in patients with multiple TIAs. They studied clinical characteristics, acute STROKE treatment (TOAST) classification, and risk of stroke in 1000 consecutive patients with incident and recurrent TIAs as part of the prospective, population-based Oxford Vascular Study. Of the 1000 patients with TIAs, 170 had a further TIA Յ7 days (105 Յ24 hours). Multiple TIAs were not associated with carotid stenosis or atrial fibrillation. Much of the 10.6% (95% confidence interval [CI], 6.5%-15.9%) risk of stroke in the first 7 days after the an initial TIA was due to patients with small-vessel disease (SVD) etiology (10 of 24 vs 8 of 146; odds ratio, 12.3; 95% confidence interval, 3.7-41.9; P ϭ .0001), particularly in those with motor weakness (ie, capsular warning syndrome) compared with hemisensory events (9 of 15 [60%], 95% CI, 35.3-84.7 vs 1 of 9 [11.1%], 95% CI, 0-31.7; P ϭ .03). The 7-day risk of stroke after recurrent TIA was similar to the risk after a single TIA in patients with non-SVD TIA (8 of 146 [5.5%] vs 76 of 830 [9.2%]; odds ratio, 0.58; 95% CI, 0.25-1.3; P ϭ .20). All of the nine patients with stroke after a capsular warning syndrome had recurrent TIA Յ24 hours after the first TIA, and the subsequent stroke occurred Յ72 hours of the second TIA in eight patients. The ABCDE2 scores of all preceding TIAs were Յ4 in all nine patients with capsular warning syndrome before their stroke.Comment: The data point out that not all TIAs have the same prognosis for stroke. In particular, multiple TIAs without association with large-vessel disease may have the worst prognosis of all. The implication is that the emphasis on recurrent TIAs in many societal guidelines scores may not be justified. At least in this study, multiple T...

Guidelines for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack

“…Of those taking aspirin, 43% were deemed to be nonresponders, as were 35% of those taking clopidogrel. 556 Of the 324 total patients in the study, 73 had their antiplatelet regimen modified and 251 did not. The rate of subsequent death, bleeding, or ischemic events with or without propensity score adjustment was significantly higher when modification…”

How I use laboratory monitoring of antiplatelet therapy

“…In any event, the relationship is weaker than that between high platelet reactivity and thrombotic events, 78 and there is no convincing evidence that changing clopidogrel therapy based on platelet function monitoring can result in a reduction in bleeding events and some evidence that it may increase bleeding events. 79 However, we perform platelet function testing to (a) confirm suspected nonadherence in patients taking clopidogrel (or other antiplatelet therapy) or to confirm suspected nonadherence in patients with ischemic events 42,49 and (2) to determine the timing of cardiac surgery following withdrawal of a P2Y 12 inhibitor to provide reassurance to the surgeon and allow earlier operation in patients with urgent indications but in whom the surgeon may otherwise feel For personal use only. on May 10, 2018. by guest www.bloodjournal.org From obligated to wait the requisite number of days listed in the drug labeling or guidelines.…”

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