Intravenous Thrombolysis in Unknown-Onset Stroke: Results From the Safe Implementation of Treatment in Stroke-International Stroke Thrombolysis Registry

Characteristics and outcomes of unknown onset stroke: The Japan Stroke Data Bank

BACKGROUND

Clinical outcomes of unknown onset stroke (UOS) are influenced by the enlargement of the therapeutic time window for reperfusion therapy. This study aimed to investigate and describe the characteristics and clinical outcomes of patients with UOS.

METHODS

Patients with acute ischemic stroke (AIS) who were admitted within 24 h of their last known well time, from January 2017 to December 2020, were included. Data were obtained from a long-lasting nationwide hospital-based multicenter prospective registry: the Japan Stroke Data Bank. The co-primary outcomes were the National Institutes of Stroke Scale (NIHSS) scores on admission and unfavorable outcomes at discharge, corresponding to modified Rankin Scale (mRS) scores of 3-6.

RESULTS

Overall, 26,976 patients with AIS were investigated. Patients with UOS (N = 5783, 78 ± 12 years of age) were older than patients with known onset stroke (KOS) (N = 21,193, 75 ± 13 years of age). Age, female sex, higher premorbid mRS scores, atrial fibrillation, and congestive heart failure were associated with UOS in multivariate analysis. UOS was associated with higher NIHSS scores (median = 8 [interquartile range [IQR]: 3-19] vs. 4 [1-10], adjusted incidence rate ratio = 1.37 [95% CI: 1.35-1.38]) and unfavorable outcomes (52.1 vs. 33.6%, adjusted odds ratio = 1.27 [1.14-1.40]). Intergroup differences in unfavorable outcomes were attenuated among females (1.12 [0.95-1.32] vs. males 1.38 [1.21-1.56], P = 0.040) and in the subgroup that received reperfusion therapy (1.10 [0.92-1.33] vs. those who did not receive therapy 1.23 [1.08-1.39], P = 0.012).

CONCLUSIONS

UOS was associated with unfavorable outcomes but to a lesser degree among females and patients receiving reperfusion therapy.

Safety of intravenous thrombolysis in stroke of unknown time of onset: A systematic review and meta-analysis

The safety of intravenous tissue plasminogen activator (IV-tPA) in patients with stroke of unknown time of onset (SUTO) was unclear and mostly concerned. We sought to investigate the safety in terms of symptomatic intracranial hemorrhage (sICH) and death in SUTO patients treated with IV-tPA. We searched PubMed and EMBASE from inception to 2 December 2020 for eligible studies reporting IV-tPA in SUTO patients compared to conservative medical therapy, or to stroke of known onset time (SKOT) treated with IV-tPA within standard time window. We pooled relative risk (RR) with 95% confidence interval (95%CI) with random-effects model. Twenty-four studies were included, enrolling 77,398 patients. SUTO patients with IV-tPA had higher incidence of sICH than that in SUTO patients without IV-tPA (3.8% versus 0.96%; RR = 3.75, 95%CI: 2.69-5.22) but comparable to that in SKOT patients with IV-tPA (3.8% versus 4.1%; RR = 1.16, 95%CI: 0.94-1.44). There was no significant difference in death risk in SUTO patients with IV-tPA versus SUTO patients without IV-tPA (RR = 1.34, 95%CI: 0.60-3.01) and versus SKOT patients with IV-tPA (RR = 1.19, 95%CI: 0.95-1.50). Compared with SUTO patients without IV-tPA, SUTO patients with IV-tPA had higher likelihood of favorable functional outcome (adjusted RR = 1.28, 95%CI: 1.03-1.60) and functional independence (adjusted RR = 1.95, 95%CI: 1.24-3.06), comparable to that in SKOT patients with IV-tPA in favorable functional outcome (adjusted RR = 0.67, 95%CI: 0.38-1.20) and functional independence (adjusted RR = 0.84, 95%CI: 0.59-1.18). SUTO patients could be treated safely and effectively with IV-tPA under the guidance of imaging evaluation.

Efficacy and Safety of Intravenous Thrombolysis in Patients with Unknown Onset Stroke: A Meta-Analysis

Objectives

Unknown onset stroke (UOS) is usually excluded from intravenous thrombolysis concerning the unclear symptom onset time. Attempts have been done to use thrombolytic therapy in these patients. The current meta-analysis was done to examine the efficacy and safety of intravenous thrombolysis in UOS.

Methods

PubMed, Web of Science, and Cochrane Library were searched for studies comparing thrombolysis with conservative therapy among UOSs. Data of good outcome (mRS, 0-2), mortality, and intracerebral hemorrhage (ICH) and symptomatic ICH (sICH) were extracted and analyzed using the Revman 5.2 software.

Results

In total, 8 studies with 1271 subjects (542 with thrombolysis and 729 with conservative therapy) were included in this meta-analysis. The data showed that patients receiving thrombolysis had a higher incidence of 90-day good outcome (P = 0.0005) than conservative therapy. The comparison of discharge (P = 0.89) and 90-day mortality (P = 0.10) in both groups did not find any significances. The incidences of ICH (P = 0.42) and sICH (P = 0.06) were relatively comparable between the two therapies.

Conclusions

Intravenous thrombolysis is a better choice for UOS patients for its efficacy and safety. In addition, pretreatment imaging assessment is beneficial for improving the efficacy of thrombolytic therapy. However, it needs more supporting evidences for clinical use in the future.

Update on Neurocritical Care of Stroke

PURPOSE OF REVIEW

This review will highlight the recent advancements in acute ischemic stroke diagnosis and treatment, with special attention to new features and recommendations of stroke care in the neurocritical care unit.

RECENT FINDINGS

New studies suggest that pre-hospital treatment of stroke with mobile stroke units and telestroke technology may lead to earlier stroke therapy with intravenous tissue plasminogen activator (tPA), and recent studies show tPA can be given in previously contraindicated situations. More rapid automated CT perfusion and angiography may demonstrate a vascular penumbra for neuroendovascular intervention. Further, the greatest advance in acute stroke treatment since 2014 is the demonstration that neuroendovascular catheter-based thrombectomy with stent retrievers recanalizing intracranial large vessel occlusion (LVO) improves both recanalization and long-term outcomes in several trials. Hemorrhagic transformation and severe large infarct cerebral edema remain serious post-stroke challenges, with new guidelines describing who and when patients should get medical or surgical intervention. The adage "time is brain" directs the most evidence-based approach for rapid stroke diagnosis for tPA eligible and LVO recanalization using an orchestrated team approach. The neurocritical care unit is the appropriate location to optimize stroke outcomes for the most severely affected stroke patients.