Presumed Ischemic Stroke Research Articles

Piracetam in acute stroke: a systematic review

We studied whether the administration of piracetam in acute, presumed ischemic stroke affects case fatality and functional outcome. The Cochrane Stroke Group strategy was used to evaluate all randomized controlled trials of patients with presumed ischemic stroke examined within 48 h; death and (when available) functional outcome were used as end points. Three studies were included; the most recent one contributed more than 97% of the data. There were 501 patients treated with piracetam and 501 controls. Piracetam was associated with a nonsignificant 31% increase in the odds of death (95% CI -5% to 81%). This result was due almost completely to the effect of the larger trial, which, however, reported that the difference in case fatality rate between piracetam and control disappeared after correcting for the imbalance in stroke severity between the two groups. Data on functional outcome were available only for the largest study, and no difference was reported. Data obtained from the manufacturer suggested a nonsignificant trend (-10%) towards reduction in dependency with piracetam (CI -33% to 20%); the proportions of patients dead or dependent in the two groups were the same. Relevant adverse effects were not reported. The evidence from this review does not support routine administration of piracetam in patients with acute ischemic stroke; however, since a possible beneficial effect cannot completely be ruled out, further controlled trials are warranted.

Computed tomography findings in the first few hours of ischemic stroke: implications for the clinician.

In order to evaluate the clinical usefulness of emergency computed tomography (CT) in acute ischemic stroke, we assessed whether CT findings within the first few hours of stroke onset reliably predict type, site and size of the index infarction, and risk of death or disability. For this reason we reviewed clinical and CT findings in a cohort of unselected consecutive patients referred to the stroke unit of a large urban hospital because of a presumed ischemic stroke in the anterior circulation (AC), and submitted to CT within 5 h from onset. Out of 158 total patients, emergency CT revealed parenchymal changes compatible with AC focal ischemia in 77 (49%) and a hyperdense middle cerebral artery (MCA) in 41 (26%). Parenchymal changes and hyperdense MCA predicted an AC territorial infarction respectively in 97% of cases (95% C.I. 93% to 100%) and in 95% of cases (95% C.I. 88% to 100%). Site and size of early changes coincided with those of final lesions in 79% of patients with cortical changes and in 95% of patients with cortico-subcortical changes, but only in 37% of patients with initial subcortical changes, the remainder of whom developed a cortico-subcortical infarction. At logistic regression parenchymal changes were the only independent predictor of an AC territorial infarction. Negative predictive power, however, was only 40% (95% C. I. 29% to 51%) for parenchymal changes, and 35% for hyperdense MCA (95% C.I. 26% to 44%). The odds for death or disability at 1 month associated with parenchymal changes were thrice as high as with negative CT, even after adjustment for clinical severity on admission. These results indicate that CT scan adds significantly to the prediction of outcome made on clinical grounds. The frequent development of a territorial infarction in patients with initially negative CT and the subsequent recruitment of the cortex in those initially exhibiting only subcortical changes suggest that the transition from ischemia to infarction often occurs after the first five h following stroke.

Accuracy of ICD-9-CM coding for the identification of patients with acute ischemic stroke: effect of modifier codes.

Discharge ICD-9-CM (International Classification of Diseases, 9th Revision, Clinical Modification) codes have been used to identify patients with acute stroke for epidemiological, quality of care, and cost studies. The aim of this study was to determine if the accuracy of the primary ICD-9-CM codes for ischemic stroke is improved by modifier codes and how specific codes reflect stroke subtype diagnoses. Available hospital charts for all patients discharged from a single hospital between May 1995 and June 1997 with ICD-9-CM codes 433 (occlusion and stenosis of precerebral arteries), 434 (occlusion of cerebral arteries), or 436 (acute but ill-defined cerebrovascular disease) listed in the first position were reviewed. The primary discharge diagnosis was verified, and a presumed stroke subtype was assigned on the basis of information provided in the medical record. Charts were available for 175 of the 198 identified patients (88%). Of these, 61% had an acute ischemic stroke (code 433, 4%; 434, 82%; 436, 79%) with the remaining patients having other conditions. Of the 130 patients with a modifier code indicating cerebral infarction, 79% had an acute stroke; of the 45 patients with a modifier code indicating an absence of cerebral infarction, 7% had acute stroke (sensitivity, 0.97; specificity, 0.60). The codes with the highest proportions of ischemic stroke cases were 434.11 (embolic occlusion of cerebral arteries with infarction, 85%), 434.91 (unspecified occlusion of precerebral arteries with infarction, 82%), and 436 (79%), with a combined sensitivity of 0.81 and specificity of 0.90. On review, 73% of patients with code 434.11 had embolic strokes, and 47% of those with code 436 had an identified stroke cause. Of patients with code 434.91, 39% had stroke of uncertain cause, 25% "lacunar," 17% atherothrombosis, and 15% embolism. Despite the use of modifier codes, 15% to 20% of patients with the indicated primary ICD-9-CM codes have conditions other than acute ischemic stroke. Although the proportion of patients with acute stroke increased from 61% to 79% with the use of modifier codes, the inclusion of modifier codes did not have an appreciable effect on the accuracy of the coding if patients with code 433 are excluded. Assignment of presumed ischemic stroke subtype is particularly inaccurate.

High-density lipoprotein cholesterol and risk of ischemic stroke mortality. A 21-year follow-up of 8586 men from the Israeli Ischemic Heart Disease Study.

While there is overwhelming evidence relating low levels of HDL cholesterol (HDL-C) with coronary heart disease, the association with cerebrovascular disease is not clear. The aim of the present report was to assess the association between HDL-C levels and ischemic stroke mortality obtained from a long-term follow-up in the Israeli Ischemic Heart Disease Study. The subjects of this report are 8586 men, tenured civil servants and municipal employees, aged 42 years or older at the time of HDL-C measurements in 1965. They were followed up for mortality for 21 years. Death due to cerebrovascular disease included the International Classification of Disease, 9th Revision, codes 430 to 438, of which presumed ischemic stroke included codes 433 to 438. During the 21-year follow-up, 295 men died from cerebrovascular events, of which 241 deaths were due to presumed ischemic stroke. Individuals subsequently experiencing a fatal ischemic stroke had a marginally lower age-adjusted mean HDL-C (1.05 mmol/L) and a significantly lower (P < .001) age-adjusted mean percentage of serum cholesterol contained in the HDL fraction (%HDL) (19.3%) than counterparts surviving the follow-up period (1.06 mmol/L and 20.6%, respectively). Decreasing age-adjusted rates of ischemic stroke mortality were observed with increasing %HDL: 14.6, 14.0, and 11.8 per 10,000 person-years in the low, middle, and upper tertiles of %HDL, respectively. In multivariate analysis, a low concentration of HDL-C appeared to be significantly predictive of ischemic stroke mortality. The relative risk associated with a 5% decrease of %HDL was 1.18 (95% confidence interval, 1.03 to 1.34). Men at the lower tertile of HDL-C levels experienced a 1.32-fold increase of covariate-adjusted ischemic stroke mortality risk compared with counterparts at the upper tertile. In this prospective study of middle-aged and elderly men from a healthy, working population, we have demonstrated an independent negative association between HDL-C and ischemic stroke mortality during a long-term (21-year) follow-up.

Antithrombotic Therapy in Acute Ischemic Stroke

In the January 23,1995, issue of theARCHIVES, Becker and Ansell 1 present a synopsis of the third American College of Chest Physicians Consensus Conference on Antithrombotic Therapy. In the clinical guidelines presented, they recommended the routine use of subcutaneous heparin therapy for the prevention of venous thromboembolism in patients with ischemic stroke. For the management of acute cardioembolic stroke, they recommend intravenous heparin. However, this advice is not supported by the available evidence. In a recent systematic review of 10 randomized controlled trials comparing anticoagulants with control (including about 1000 patients with acute presumed ischemic stroke), allocation to anticoagulant therapy was associated with a highly significant 81% reduction ( P 2 However, there were insufficient data on the risk of death, intracranial hemorrhage, and functional outcomes to provide reliable evidence on the effect of treatment on these infrequent, but