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Parenchymal hypodensity is a proposed risk factor for hemorrhage after recombinant tissue plasminogen activator (TPA) thrombolysis for ischemic stroke. In Buffalo, NY, and Houston, TX, the authors reviewed 70 patients who were treated with intravenous TPA for acute middle cerebral artery (MCA) stroke. Two observers blinded to clinical outcome analyzed initial noncontrast head computed tomography (CT) scans. Basal ganglia CT hypodensity was quantitated in Hounsfield units (HUs). Contralateral-ipsilateral difference in density was calculated using the asymptomatic side as a control. Ictus time to TPA averaged 2.5 hours. Six patients developed symptomatic intraparenchymal hematomas (2 fatal). The hemorrhage group had more severe basal ganglia hypodensity (mean 7.5 +/- 1.4, range 6-10 HU) than the nonhemorrhage group (2.2 +/- 1.4, range 0-9 HU) (P < .0001). The hemorrhage group had hypodensity of > 5 HU; the nonhemorrhage group had hypodensity of < or = 4 HU, except 1 patient with hypodensity of 9 HU. In predicting hemorrhage, the positive predictive value of hypodensity > 5 HU was 86%; the negative predictive value was 100%. Prethrombolysis NIH Stroke Scale (NIHSS) deficit (P = .0007) and blood glucose (P = .005) were also higher in the hemorrhage group. Age, gender, smoking, hypertension, and ictus time to TPA infusion did not differ between the 2 groups. Logistic regression indicated that basal ganglia hypodensity was the best single predictor of hemorrhage. Hypodensity and NIHSS score together predicted all cases of hemorrhage. The authors conclude that basal ganglia hypodensity quantified by CT may be a useful method of risk stratification to select acute MCA stroke patients for thrombolytic therapy.

Objective: A literature review of antiplatelet agents for primary and secondary stroke prevention, including mechanism of action, cost, and reasons for lack of benefit. Data sources: Articles were gathered from MEDLINE, Cochrane Reviews, and PubMed databases (1980-2021). Abstracts from scientific meetings were considered. Search terms included ischemic stroke, aspirin, clopidogrel, dipyridamole, ticagrelor, cilostazol, prasugrel, glycoprotein IIb/IIIa inhibitors. Study selection and data extraction: English-language original and review articles were evaluated. Guidelines from multiple countries were reviewed. Articles were evaluated independently by 2 authors. Data synthesis: An abundance of evidence supports aspirin and clopidogrel use for secondary stroke prevention. In the acute phase (first 21 days postinitial stroke), these medications have higher efficacy for preventing further stroke when combined, but long-term combination therapy is associated with higher hemorrhage rates. Antiplatelet treatment failure is influenced by poor adherence and genetic polymorphisms. Antiplatelet agents such as cilostazol may provide extra benefit over clopidogrel and aspirin, in certain racial groups, but further research in more diverse ethnic populations is needed. Relevance to patient care and clinical practice: This review presents the data available on the use of different antiplatelet agents poststroke. Dual therapy, recurrence after initiation of secondary preventative therapy, and areas for future research are discussed. Conclusions: Although good evidence exists for the use of certain antiplatelet agents postischemic stroke, there are considerable opportunities for future research to investigate personalized therapies. These include screening patients for platelet polymorphisms that confer antiplatelet resistance and for randomized trials including more racially diverse populations.

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