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Background: Extending the therapeutic window of intravenous thrombolysis for acute ischemic stroke beyond the established 4.5-hour limit is of critical importance in order to increase the proportion of thrombolysed stroke patients. In this setting, the capacity of MRI to select acute stroke patients for reperfusion therapies in delayed time windows has been and is being tested in clinical trials. However, whether the more available and cost-effective perfusion computed tomography (PCT) may be useful to select candidates for delayed intravenous thrombolysis remains largely unexplored. We aimed to evaluate the safety and efficacy of PCT-guided intravenous thrombolysis beyond 4.5 h after stroke onset. Methods: We prospectively studied all consecutive acute ischemic stroke patients treated with intravenous tissue plasminogen activator (tPA) in our stroke unit between January 2008 and December 2010. Patients treated within 0- 4.5 h were treated according to non-contrast CT (NCCT) criteria. Beyond 4.5 h, patients received intravenous tPA according to PCT criteria, i.e. an infarct core on cerebral blood volume (CBV) maps not exceeding one third of the middle cerebral artery (MCA) territory and tissue at risk as defined by mean transit time-CBV mismatch greater than 20%. Predetermined primary endpoints were symptomatic hemorrhagic transformation and favorable long-term outcome, while early neurological improvement and MCA recanalization were considered secondary endpoints. Statistical analysis included bivariate comparisons between the two groups for each endpoint and logistic regression models when significance was found in bivariate analyses. This study was approved by our local ethics committee. Results: A total of 245 patients received intravenous thrombolysis. After the groups were matched by baseline National Institutes of Health Stroke Scale score, 172 patients treated at <4.5 h and 43 patients treated at >4.5 h were finally included. Early and late groups were comparable regarding baseline variables; only cardioembolic etiology was more frequent in the >4.5 h group. Rates of symptomatic hemorrhagic transformation (2.9% in the <4.5 h group vs. 2.3% in the >4.5 h group; p = 1.0) and good long-term outcome (64.5 vs. 60.5%, respectively; p = 0.620) were similar between the groups. However, delayed intravenous thrombolysis was independently associated with a worse early clinical course [odds ratio (OR) 2.07, 95% confidence interval (CI) 1.04-4.1; p = 0.038] and lower 2-hour MCA recanalization rates (OR 0.4, 95% CI 0.17-0.92; p = 0.03). Conclusion: Primary safety and efficacy endpoints were comparable between the early and delayed thrombolysis groups. The results of our exploratory study may justify a randomized clinical trial to test the safety and efficacy of PCT-guided intravenous thrombolysis in acute ischemic stroke patients presenting beyond 4.5 h from symptom onset. Copyright © 2012 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Extending the therapeutic window of intravenous thrombolysis for acute ischemic stroke beyond the established 4.5-hour limit is of critical importance in order to increase the proportion of thrombolysed stroke patients. In this setting, the capacity of MRI to select acute stroke patients for reperfusion therapies in delayed time windows has been and is being tested in clinical trials. However, whether the more available and cost-effective perfusion computed tomography (PCT) may be useful to select candidates for delayed intravenous thrombolysis remains largely unexplored. We aimed to evaluate the safety and efficacy of PCI-guided intravenous thrombolysis beyond 4.5 h after stroke onset. Methods: We prospectively studied all consecutive acute ischemic stroke patients treated with intravenous tissue plasminogen activator (tPA) in our stroke unit between January 2008 and December 2010. Patients treated within 0-4.5 h were treated according to non-contrast CI (NCCI) criteria. Beyond 4.5 h, patients received intravenous tPA according to PCT criteria, i.e. an infarct core on cerebral blood volume (CBV) maps not exceeding ore third of the middle cerebral artery (MCA) territory and tissue at risk as defined by mean transit time-CBV mismatch greater than 20%. Pre-determined primary endpoints were symptomatic hemorrhagic transformation and favorable long-term outcome, while early neurological improvement and MCA recanalization were considered secondary endpoints. Statistical analysis included bivariate comparisons between the two groups for each endpoint and logistic regression models when significance was found in bivariate analyses. This study was approved by our local ethics committee. Results: A total of 245 patients received intravenous thrombolysis. After the groups were matched by baseline National Institutes of Health Stroke Scale score, 172 patients treated at <4.5 hand 43 patients treated at >4.5 h were finally included. Early and late groups were comparable regarding baseline variables; only cardioembolic etiology was more frequent in the >4.5 h group. Rates of symptomatic hemorrhagic transformation (2.9% in the <4.5 h group vs. 2.3% in the >4.5 h group; p = 1.0) and good long-term outcome (64.5 vs. 60.5%, respectively; p = 0.620) were similar between the groups. However, delayed intravenous thrombolysis was independently associated with a worse early clinical course [odds ratio (OR) 2.07, 95% confidence interval (Cl) 1.04-4.1; p = 0.038] and lower 2-hour MCA recanalization rates (OR 0.4, 95% Cl 0.1 7-0.92; p = 0.03). Conclusion: Primary safety and efficacy endpoints were comparable between the early and delayed thrombolysis groups. The results of our exploratory study may justify a randomized clinical trial to test the safety and efficacy of PCT-guided intravenous thrombolysis in acute ischemic stroke patients presenting beyond 4.5 h from symptom onset. [ABSTRACT FROM AUTHOR]

OBJECTIVE--Insulin resistance (IR) may not only increase stroke risk, but could also contribute to aggravate stroke prognosis. Mainly through a derangement in endogenous brinolysis, IR could affect the response to intravenous thrombolysis, currently the only therapy proved to be efficacious for acute ischemic stroke. We hypothesized that high IR is associated with more persistent arterial occlusions and poorer long-term outcome after stroke thrombolysis. RESEARCH DESIGN AND METHODS--We performed a prospective, observational, longitudinal study in consecutive acute ischemic stroke patients presenting with middle cerebral artery (MCA) occlusion who received intravenous thrombolysis. Patients with acute hyperglycemia (≥155 mg/dL) receiving insulin were excluded. IR was determined during admission by the homeostatic model assessment index (HOMA-IR). Poor long-term outcome, as defined by a day 90 modified Rankin scale score ≥3, was considered the primary outcome variable. Transcranial Duplex-assessed resistance to MCA recanalization and symptomatic hemorrhagic transformation were considered secondary end points. RESULTS--A total of 109 thrombolysed MCA ischemic stroke patients were included (43.1% women, mean age 71 years). The HOMA-IR was higher in the group of patients with poor outcome (P = 0.02). The probability of good outcome decreased gradually with increasing HOMA-IR tertiles (80.6%, 1st tertile; 71.4%, 2nd tertile; and 55.3%, upper tertile). A HOMA-IR in the upper tertile was independently associated with poor outcome when compared with the lower tertile (odds ratio [OR] 8.54 [95%CI 1.67--43.55]; P = 0.01) and was associated with more persistent MCA occlusions (OR 8.2 [1.23--54.44]; P =0.029) . CONCLUSIONS--High IR may be associated with more persistent arterial occlusions and worse long-term outcome after acute ischemic stroke thrombolysis. [ABSTRACT FROM AUTHOR]

A response by Al Calleja and colleagues to a letter to the editor about their article "Insulin Resistance Is Associated With a Poor Response to Intravenous Thrombolysis in Acute Ischemic Stroke" in a 2011 issue is presented.

Background We describe the feasibility of monitoring with a Textile Wearable Holter (TWH) in patients included in Crypto AF registry. Methods We monitored cryptogenic stroke patients from stroke onset (< 3 days) continuously during 28 days. We employed a TWH composed by a garment and a recorder. We compared two garments (Lead and Vest) to assess rate of undiagnosed Atrial Fibrillation (AF) detection, monitoring compliance, comfortability (1 to 5 points), skin lesions, and time analyzed. We describe the timing of AF detection in three periods (0–3, 4–15 and 16–28 days). Results The rate of undiagnosed AF detection with TWH was 21.9% (32 out of 146 patients who completed the monitoring). Global time compliance was 90% of the time expected (583/644 h). The level of comfortability was 4 points (IQR 3–5). We detected reversible skin lesions in 5.47% (8/146). The comfortability was similar but time compliance (in hours) was longer in Vest group 591 (IQR [521–639]) vs. Lead 566 (IQR [397–620]) (p = 0.025). Also, time analyzed was more prolonged in Vest group 497 (IQR [419–557]) vs. Lead (336 h (IQR [140–520]) (p = 0.001)). The incidence of AF increases from 5.6% (at 3 days) to 17.5% (at 15th day) and up to 20.9% (at 28th day). The percentage of AF episodes detected only in each period was 12.5% (0–3 days); 21.7% (4–15 days) and 19% (16–28 days). Conclusions 28 days Holter monitoring from the acute phase of the stroke was feasible with TWH. Following our protocol, only five patients were needed to screen to detected one case of AF. [ABSTRACT FROM AUTHOR]

We aimed to study the relationship between the ischemic core's (IC) radiological hypodensity and the risk of parenchymal haematoma after endovascular therapy (EVT) in acute ischemic stroke (AIS) presenting > 4.5 h from onset. We studied AIS patients with a proximal anterior circulation occlusion > 4.5 h from symptoms onset treated with primary EVT. The IC regions of interest (ROI) were manually delineated on pretreatment CT within the affected hemisphere and their specular ROIs on the unaffected side. IC hypodensity ratio was calculated by dividing mean Hounsfield Unit (HU) value from all ROIs in affected/unaffected hemisphere. Primary endpoint: parenchymal hematoma (PH) type hemorrhagic transformation. Secondary: poor long-term clinical outcome. From May 2015 to November 2018, 648 consecutive AIS patients received reperfusion therapies and 107 met all inclusion criteria. PH after EVT was diagnosed in 33 (31%) patients. In bivariate analyses, IC hypodensity ratio (p < 0.001) and minimum HU value (p = 0.008) were associated with PH. A lower IC hypodensity ratio [OR < 0.001 (< 0.001–0.116) p 0.016] predicted PH but not poor clinical outcome in multivariable logistic regression models. A lower IC radiological density predicted a higher risk of PH in > 4.5 h-window AIS patients treated with primary EVT, although it was not independently associated with a worse clinical outcome. [ABSTRACT FROM AUTHOR]