Is vascular imaging valuable prior to administration of intravenous tissue plasminogen activator?

Our goals were to explore whether performing computerized tomography angiography (CTA) prior to administration of tissue plasminogen activator (tPA) delays treatment and impacts outcome in patients with proximal middle cerebral artery occlusions (pMCAO). Patients with pMCAO with a National Institutes of Health Stroke scale (NIHSS) score >10 were identified from a prospective Stroke Registry. Patients underwent multi-parametric imaging studies whenever possible. Patients who underwent CTA were compared to those who only had non-contrast CT scan. Disability was measured with the modified Rankin Scale. Logistic regression was used to determine outcome modifiers. We included 73 patients (median age 73 years, 52% men) with moderate-severe stroke (median admission NIHSS 14). Of those, 44 underwent CTA and 29 did not. There were no differences between the groups in risk factor profile or baseline characteristics including stroke severity and door to needle, door to imaging or imaging to treatment times. At 90 days post-stroke there were no statistically significant differences in outcomes between the groups. On multivariate analysis, performing CTA had no impact on the chance of obtaining favorable outcome. In conclusion, CTA does not have a major impact on outcome in patients with pMCAO treated with tPA. Therefore, performing CTA should be considered on an individual basis prior to administration of tPA.     

Which targets are relevant for therapy of acute ischemic stroke?

BACKGROUND: The efficiency of various strategies of neuroprotection is well documented in animal experiments but is thus far disappointing in ischemic stroke, for which only early reperfusion induced by thrombolysis has improved clinical outcome. This discrepancy between expectation from experimental research and clinical reality may be related to differences in the pathogenetic factors contributing to infarction. SUMMARY OF COMMENT: Positron emission tomography cerebral blood flow studies within 3 hours of onset were used to identify the various compartments of the infarct outlined on MRI 2 to 3 weeks after a hemispheric stroke in 10 patients. Critical hypoperfusion below the viability threshold accounted for the largest proportion (mean, 70%) of the final infarct, whereas penumbral tissue (18%) and initially sufficiently perfused tissue (12%) were responsible for considerably smaller portions of the final infarct. CONCLUSIONS: These results indicate that early critical flow disturbance leading to rapid cell damage is the predominant cause of infarction, while secondary and delayed pathobiochemical processes in borderline or initially sufficiently perfused regions contribute only little to the final infarct. Therefore, emerging therapeutic strategies should be targeted to the initially critically perfused tissue subcompartments. Clinical drug trials might benefit from stratification of patients for target tissue compartments applying functional imaging.     

Is there a bad time for intravenous thrombolysis? The experience of Polish stroke centers

Background and purposeThe outcome in acute stroke strongly depends on patient-related issues, as well as on the availability of human and diagnostic resources. Our aim was to evaluate safety and effectiveness of intravenous alteplase for stroke according to the time of admission to the hospital.Materials and methodsWe analyzed the data of all acute stroke patients treated with alteplase between October 2003 and December 2010, contributed to the Safe Implementation of Thrombolysis for Stroke registry from 27 Polish stroke centers. According to the time of admission we distinguished between: (1) non-working days (Friday 14:30–Monday 08:00 plus national holidays); (2) out-of-office hours (non-working days plus 14:30–08:00 during working days); and (3) night hours (time from 23:00 to 06:00). Patients admitted during regular working hours (Monday 08:00–Friday 14:30, excluding national holidays) were used as the reference.ResultsOf 1330 patients, 448 (32.5%) were admitted on non-working days, 868 (65.3%) at out-of-office hours, and 105 (7.9%) during night hours. In multivariate logistic regression, none of the evaluated periods showed association with symptomatic intracranial hemorrhage, 7-day mortality, and neurological improvement ≥4 points in the National Institutes of Health Stroke Scale score at day 7. Patients admitted during night hours had lower odds (OR 0.53, 95% CI: 0.29–0.95, p = 0.032) for achieving favorable outcome (modified Rankin Scale score 0–2).ConclusionsThere is no bad time for thrombolysis. Stroke centers should feel confident about the treatment outside regular working hours, irrespective of equipment and staff availability. However, it may be reasonable to pay additional attention during nighttime.