Thrombolysis targeting MRI defined tissue at risk in minor stroke

Target Door-to-Needle Time for Tissue Plasminogen Activator Treatment with Magnetic Resonance Imaging Screening Can Be Reduced to 45 min

Objective: The purpose of this study was to demonstrate that the median door-to-needle (DTN) time for intravenous tissue plasminogen activator (tPA) treatment can be reduced to 45 min in a primary stroke centre with MRI-based screening for acute ischaemic stroke (AIS). Methods: From February 2015 to February 2017, the stroke unit of Perpignan general hospital, France, implemented a quality-improvement (QI) process. During this period, patients who received tPA within 4.5 h after AIS onset were included in the QI cohort. Their clinical characteristics and timing metrics were compared each semester and also with those of 135 consecutive patients with AIS treated by tPA during the 1-year pre-QI period (pre-QI cohort). Results: In the QI cohort, 274 patients (92.5%) underwent MRI screening. While the demographic and baseline characteristics were not significantly different between cohorts, the median DTN time was significantly lower in the QI than in the pre-QI cohort (52 vs. 84 min; p < 0.00001). Within the QI cohort, the median DTN time for each semester decreased from 65 to 44 min (p < 0.00001) and the proportion of treated patients with a DTN time ≤45 min increased from 25 to 58.9% (p < 0.0001). Overall, DTN time improvement was associated with a better outcome at 3 months (patients with a modified Rankin Scale score between 0 and 2: 61.8% in the QI vs. 39.3% in the pre-QI cohort; p < 0.0001). Conclusions: A QI process can reduce the DTN within 45 min with MRI as a screening tool.

Clinical and Imaging Outcomes of Endovascular Therapy in Patients with Acute Large Vessel Occlusion Stroke and Mild Clinical Symptoms

Background

The minimal stroke severity justifying endovascular intervention remains elusive. However, a significant proportion of patients presenting with large vessel occlusion stroke (LVOS) and mild symptoms go untreated and face poor outcomes. We aimed to evaluate the clinical outcomes of patients presenting with LVOS and low symptom scores (National Institutes of Health Stroke Scale [NIHSS] score ≤8) undergoing endovascular therapy (ET).

Methods

We performed a retrospective analysis of a prospectively collected ET database between September 2010 and March 2016. Endovascularly treated patients with LVOS and a baseline NIHSS score ≤8 were included. Baseline patient characteristics, procedural details, and outcome parameters were collected. Efficacy outcomes were the rate of good outcome (90-day modified Rankin Scale score 0-2) and of successful reperfusion (modified Treatment in Cerebral Infarction [mTICI] score 2b-3). Safety was assessed by the rate of parenchymal hematoma (parenchymal hematoma type 1 [PH-1] and parenchymal hematoma type 2 [PH-2]) and 90-day mortality. Logistic regression was used to identify predictors of good clinical outcomes.

Results

A total of 935 patients were considered; 72 patients with an NIHSS score ≤8 were included. Median [IQR] age was 61.5 years [56.2-73.0]; 39 patients (54%) were men. Mean (SD) baseline NIHSS score, computed tomography perfusion core volume, and ASPECTS were 6.3 (1.5), 7.5 mL (16.1), and 8.5 (1.3), respectively. Twenty-eight patients (39%) received intravenous tissue plasminogen activator. Occlusions locations were as follows: 29 (40%) proximal MCA-M1, 20 (28%) MCA-M2, 6 (8%) ICA terminus, and 9 (13%) vertebrobasilar. Tandem occlusion was documented in 7 patients (10%). Sixty-seven patients (93%) achieved successful reperfusion (mTICI score 2b-3); 52 (72%) had good 90-day outcomes. Mean final infarct volume was 32.2 ± 59.9 mL. Parenchymal hematoma occurred in 4 patients (6%). Ninety-day mortality was 10% (n = 7). Logistic regression showed that only successful reperfusion (OR 27.7, 95% CI 1.1-655.5, p = 0.04) was an independent predictor of good outcomes.

Conclusion

Our findings demonstrate that ET is safe and feasible for LVOS patients presenting with mild clinical syndromes. Future controlled studies are warranted.

Results of a 1-year quality-improvement process to reduce door-to-needle time in acute ischemic stroke with MRI screening

OBJECTIVE

To determine the effects of a 1-year quality-improvement (QI) process to reduce door-to-needle (DTN) time in a secondary general hospital in which multimodal MRI screening is used before tissue plasminogen activator (tPA) administration in patients with acute ischemic stroke (AIS).

METHODS

The QI process was initiated in January 2015. Patients who received intravenous (iv) tPA<4.5h after AIS onset between 26 February 2015 to 25 February 2016 (during implementation of the QI process; the "2015 cohort") were identified (n=130), and their demographic and clinical characteristics and timing metrics compared with those of patients treated by iv tPA in 2014 (the "2014 cohort", n=135).

RESULTS

Of the 130 patients in the 2015 cohort, 120 (92.3%) of them were screened by MRI. The median DTN time was significantly reduced by 30% (from 84min in 2014 to 59min; P<0.003), while the proportion of treated patients with a DTN time≤60min increased from 21% to 52% (P<0.0001). Demographic and baseline characteristics did not significantly differ between cohorts, and the improvement in DTN time was associated with better outcomes after discharge (patients with a 0-2 score on the modified rankin scale: 59% in the 2015 cohort vs 42.4% in the 2014 cohort; P<0.01). During the 1-year QI process, the median DTN time decreased by 15% (from 65min in the first trimester to 55min in the last trimester; P≤0.04) with a non-significant 1.5-fold increase in the proportion of treated patients with a DTN time≤60min (from 41% to 62%; P=0.09).

CONCLUSION

It is feasible to deliver tPA to patients with AIS within 60min in a general hospital, using MRI as the routine screening modality, making this QI process to reduce DTN time widely applicable to other secondary general hospitals.

Screening with MRI for Accurate and Rapid Stroke Treatment: SMART

OBJECTIVE

The objective of this study was to demonstrate the feasibility of timely multimodal MRI screening before thrombolysis in acute stroke patients.

METHODS

Quality improvement processes were initiated in 2013 to reduce door-to-needle (DTN) time at the 2 hospitals where the NIH stroke team provides clinical care. Acute ischemic stroke (AIS) patients who received IV tissue plasminogen activator (tPA) ≤4.5 hours from last known normal were identified. Demographic and clinical characteristics and timing metrics were analyzed comparing the time periods before, during, and after the quality improvement processes.

RESULTS

There were 157 patients treated with IV tPA for AIS during 2012-2013, of whom 135 (86%) were screened with MRI. DTN time was significantly reduced by 40% during this period from a median of 93 minutes in the first half of 2012 to 55 minutes in the last half of 2013 (p < 0.0001) with a significant 4-fold increase in the proportion of treated patients with DTN time ≤60 minutes from 13.0% to 61.5%, respectively (p < 0.00001). Improvement in DTN time was associated with reduced door-to-MRI time, and there were no differences in demographic or clinical characteristics (p = 0.21-0.76).

CONCLUSIONS

It is feasible and practical to consistently and rapidly deliver IV tPA to AIS patients within national benchmark times using MRI as the routine screening modality. The processes used in the SMART (Screening with MRI for Accurate and Rapid Stroke Treatment) Study to reduce DTN time have the potential to be widely applicable to other hospitals.

Should Minor Stroke Patients Be Thrombolyzed? A Focused Review and Future Directions

Stroke is a leading cause of morbidity and mortality worldwide. Up to 80% of ischemic stroke patients may initially present with minor symptoms. Minor stroke and transient ischemic attack patients are typically treated conservatively with antiplatelet agents and general vascular prevention strategies. Yet a high proportion develop recurrent stroke or progression of stroke and up to one in four of these patients are disabled or dead at follow-up. Minor or rapidly improving symptoms are the top reasons for withholding thrombolytic therapy to time-eligible stroke patients as they are believed to be ‘too good to treat’. The benefits and risks of treating mild ischemic strokes are still unclear. The increasing use of computed tomography angiography and its ability to identify both proximal and distal intracranial occlusions may change this equation. In this review, we discuss the diagnosis and prognosis of mild strokes, the role of neurovascular imaging in treatment decision making, experience with thrombolysis in this patient population, and propose directions for future studies.

Safety and outcome of thrombolysis in mild stroke: a meta-analysis

Background

Whether patients presenting with mild stroke should or should not be treated with intravenous rtPA is still controversial. This systematic review aims to assess the safety and outcome of thrombolysis in these patients.

Material/Methods

We systematically searched PubMed and Cochrane Central Register of Controlled Trials for studies evaluating intravenous rtPA in patients with mild or rapidly improving symptoms except case reports. Excellent outcome (author reported, mainly mRS 0-1), symptomatic intracranial hemorrhage (sICH) and mortality were analyzed.

Results

Fourteen studies were included (n=1906 patients). Of these, 4 studies were comparative (2 randomized and 2 non-randomized). The remaining were single-arm studies. On the basis of 4 comparative studies with a total of 1006 patients, the meta-analysis did not identify a significant difference in the odds of excellent outcome (OR=0.86; 95% CI: 0.64–1.15; I²=0) between IV rtPA-treated minor stroke and those without rtPA treatment. Eleven studies involving 1083 patients showed the pooled rate of excellent outcome was 76.1% (95% CI: 69.8–81.5%, I²=42.5). Seven studies involving 378 patients showed the mortality rate was 4.5% (95% CI: 2.6–7.5%, I²=1.4). Twelve studies involving 831 patients showed the pooled rate of sICH was 2.4% (95% CI: 1.5–3.8, I²=0).

Conclusions

Although efficacy is not clearly established, this study reveals the adverse event rates related to thrombolysis are low in mild stroke. Intravenous rtPA should be considered in these patients until more RCT evidence is available.

Hyperdense cerebral artery computed tomography sign is associated with stroke severity rather than stroke subtype

BACKGROUND

The hyperdense cerebral artery sign (HCAS) on unenhanced computed tomography (CT) in acute ischemic stroke is a valuable clinical marker, but it remains unclear if HCAS reflects clot composition or stroke etiology. Therefore, variables independently associated with HCAS were identified from a large international data set of patients treated with intravenous thrombolysis.

METHODS

All stroke patients undergoing intravenous thrombolysis from the Safe Implementation of Treatments in Stroke-EAST (SITS-EAST) database between February 2003 and December 2011 were analyzed. A general estimating equation model accounting for within-center clustering was used to identify factors independently associated with HCAS.

RESULTS

Of all 8878 consecutive patients, 8375 patients (94%) with available information about HCAS were included in our analysis. CT revealed HCAS in 19% of patients. Median baseline National Institutes of Health Stroke Scale (NIHSS) score was 12, mean age was 67 ± 12 years, and 3592 (43%) patients were females. HCAS was independently associated with baseline NIHSS (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.10-1.12), vessel occlusion (OR, 5.02; 95% CI, 3.31-7.63), early ischemic CT changes (OR, 1.63; 95% CI, 1.31-2.04), year (OR, 1.07; 95% CI, 1.02-1.12), and age (10-year increments; OR, .90; 95% CI, .84-.96). Cardioembolic stroke was not associated with HCAS independently of baseline NIHSS. In different centers, HCAS was reported in 0%-50% of patients.

CONCLUSIONS

This study illustrates significant variation in detection of HCAS among stroke centers in routine clinical practice. Accounting for within-center data clustering, stroke subtype was not independently associated with HCAS; HCAS was associated with the severity of neurologic deficit.

Thrombolysis in patients with mild stroke: results from the Austrian Stroke Unit Registry

BACKGROUND AND PURPOSE

Apart from missing the approved time window of 4.5 hours, one frequent cause for withholding recombinant tissue plasminogen activator (rt-PA) treatment in patients with ischemic stroke is presentation with mild deficit on admission. We analyzed in a large cohort of patients whether rt-PA treatment is beneficial for this group of patients.

METHODS

From a total of 54 917 patients with ischemic stroke prospectively enrolled in the Austrian Stroke Unit Registry, 890 patients with mild deficit defined as ≤5 points in the National Institutes of Health Stroke Scale treated with and without rt-PA were matched for age, sex, prestroke disability, stroke severity, hypertension, diabetes mellitus, hypercholesterolemia, stroke cause, and clinical stroke syndrome. Functional outcome was assessed using the modified Rankin Scale at 3 months. For data visualization, weighted averages of outcome differences were computed for all age severity combinations and mapped to a color. For quantification of effect sizes, numbers need to treat were calculated.

RESULTS

rt-PA-treated patients with mild deficit had a better outcome after 3 months compared with matched cases without rt-PA treatment (odds ratio [OR], 1.49; 95% confidence interval [CI], 1.17-1.89; P<0.001). In rt-PA-treated patients with mild deficit, the numbers need to treat ranged from 8 to 14. Improvement achieved by rt-PA treatment was observed along the entire age range.

CONCLUSIONS

In our study, intravenous rt-PA treatment was beneficial for patients with mild deficit. Given the observational nature of these results, our data might serve as an incentive for future randomized controlled trials to provide a basis for optimal patient selection.

Proximal arterial occlusion in acute ischemic stroke with low NIHSS scores should not be considered as mild stroke

Background

Untreated acute mild stroke patients have substantial 90-day disability rates and worse outcomes than those who are treated with thrombolysis. There is little information regarding which patients with acute mild stroke will benefit from thrombolysis. We sought to investigate factors that are associated with early neurological deterioration (END) and poor prognosis in patients with acute mild stroke.

Methods

This was a retrospective study of consecutively registered patients with acute mild stroke (NIHSS ≤3) at our tertiary stroke center between October 2008 and December 2011. END was defined as an increase in NIHSS ≥2 points between hospital days 0 and 5. Modified Rankin Scale (mRS) scores of 0–1 at 90 days post-stroke were defined as favorable outcomes.

Results

A total of 378 (mean age, 65.9±13.0 years) patients were included in this study. END occurred in 55 patients (14.6%). IV-thrombolysis was performed in only 9 patients. Symptomatic arterial occlusion on the initial MRA was independently associated with END (OR, 2.206; 95% CI, 1.219–3.994; p = 0.009) by multivariate logistic regression. Of the 119 patients with symptomatic arterial occlusion, ICA occlusion was independently associated with END (OR, 8.606; 95% CI, 2.312–32.043; p = 0.001).

Conclusions

This study demonstrates that symptomatic arterial occlusion may be an important predictor of END in patients with acute mild stroke. It may therefore be important to consider that acute ischemic stroke with symptomatic arterial occlusion and low NIHSS scores may not represent mild stroke in acute periods.

Clinical and Radiological Features of Stroke Patients with Poor Outcomes Who Do Not Receive Intravenous Thrombolysis because of Mild Symptoms

BACKGROUND AND AIMS

A substantial proportion of patients who did not receive intravenous thrombolysis with recombinant tissue plasminogen activator (rtPA), solely because of mild symptoms, can show poor outcome. The aim of our study was to analyze clinical and radiological features of the patients.

METHODS

We enrolled 72 patients between 2007 and 2009 who presented to our hospital within 3 h after stroke onset and who did not receive rtPA therapy solely because of mild symptoms (NIHSS score of ≤ 4 at rtPA decision), and examined detailed characteristics of patients with poor outcomes. Poor outcome was defined as a modified Rankin Scale score of ≥ 2 at 3 months after the stroke.

RESULTS

Eleven of 72 patients (15%) had poor outcomes. Major vessel occlusion was observed in 7 of the 11 patients. Neurological deterioration after admission was main reason for poor outcome. Infarct expansion in 6 patients (2 large artery diseases and 4 small vessel diseases) and distal embolism by clot migration in 3 patients led to neurological deterioration.

CONCLUSIONS

Clinical and radiological features of mild stroke patients with poor outcomes, who did not receive rtPA therapy, were identified. In such patients, intravenous thrombolysis may be justified.

What is still missing in acute-phase treatment of stroke: a prospective observational study

Early recognition of stroke symptoms and activation of emergency medical service (EMS) positively affects prognosis after a stroke. To assess stroke awareness among stroke patients and medical personnel in the catchment area of Verona Hospital and how it affects stroke care, we prospectively studied timing of acute stroke care in relation to patients' characteristics. Patients admitted to Medical Departments of Verona University Hospital between January 1st and December 31st 2009 with a diagnosis of TIA or stroke were enrolled. Outcome measures were: time between (i) symptoms onset and hospital arrival, (ii) hospital arrival and brain CT scan, blood examination, ECG and neurological evaluation. The following patient/event characteristics were also collected: means of hospital arrival, sex, age, degree of disability, type of event (first or recurrent) and acute-phase treatment. Of 578 patients providing complete information, 60 % arrived to the emergency department with the EMS (EMS+ group), while 40 % arrived on their own (EMS-). EMS+ group was older than EMS- (mean age 76.2, SD 13.2, vs. 72.3, SD 13, respectively), displayed more severe symptoms (mRS 4 vs. 2) and shorter time interval between symptoms onset and hospital arrival, hospital arrival and CT scan, ECG, laboratory tests and neurological evaluation (p < 0.0001); 22 % of the EMS+ patients were stroke recurrences versus 29 % of the EMS- (p = 0.058); 85 % of thrombolised patients were EMS+. We conclude that there is a lack of awareness of stroke symptoms and risks of recurrence even among patients who already had a stroke and among medical personnel.

Intravenous tissue plasminogen activator for patients with minor ischemic stroke

BACKGROUND

Patients with minor ischemic stroke (MIS) are frequently excluded from thrombolytic therapy. Denial of therapy to these patients, however, remains controversial. We compared outcomes in patients with MIS who received intravenous (IV) tissue plasminogen activator (t-PA) with those who were not treated.

METHODS

We selected adult patients with stroke onset within 3 hours from a prospectively collected stroke registry. MIS was defined as an admission National Institutes of Health Stroke Scale (NIHSS) score ≤ 5. The primary outcome was a 90-day modified Rankin scale (mRS) score of 0 to 1. Secondary outcomes were a Barthel index (BI) score ≥ 95 at 90 days, symptomatic intracranial hemorrhage (SICH), and death. Multivariable logistic regression was performed to determine the association between outcomes adjusting for age, history of diabetes, and NIHSS score at admission. Reasons for t-PA exclusion were obtained.

RESULTS

We identified 133 patients with MIS; 59 patients received IV t-PA. The NIHSS score (mean ± SD) at admission was higher in the t-PA treated group (3.4 ± 1.4 v 1.9 ± 1.3 in the untreated group; P < .0001). Other baseline characteristics were not significantly different between the 2 groups. At 90 days, 57.6% of patients in the t-PA group and 68.9% of patients in the untreated group had a mRS score of 0 to 1 (odds ratio [OR] 0.93, 95% confidence interval [CI] 0.39-2.2; P = .87). A BI score of 95 to 100 was achieved in 75% of patients in the IV t-PA group versus 78.9% in the untreated group (OR 1.18, 95% CI 0.43-3.23; P = .74). There were 3 deaths (5.1%) in the IV t-PA group and 3 deaths (4.1%) in the control group.

CONCLUSIONS

In our sample, patients with MIS treated with IV t-PA have similar outcomes as patients not receiving thrombolysis. A randomized trial or larger observational study is needed confirm or reject these findings.

Intravenous thrombolytic treatment in a patient with transient ischemic attack associated with mural carotid thrombi

A 77-year old man experiencing frequent transient ischemic attacks for five days was admitted to our hospital. Radiological examinations including brain computed tomography, supraaortic computed tomography angiography were performed. Supraaortic computed tomography angiography revealed two thrombi in common carotid artery. Thrombi were located proximally, one of which was elongated and adhared to the arterial wall and the other one was located below bifurcation of left carotid artery. Since the case has been categorized as a high risk patient for ischemic stroke despite the normal neurological status, intravenous recombinant tissue plasminogen activator was given. Ischemic attacks completely ceased soon after thrombolysis. Control computed tomography angiography revealed normal findings with patent carotid artery, without any clot. To our knowledge this is the only case of transient ischemic attack treated with intravenous recombinant tissue plasminogen activator in the literature with the score of 0 on the National Institutes of Health Stroke Scale.

Minor stroke with total mismatch after acute MCA occlusion

BACKGROUND

Recently, "total mismatch," negative diffusion-weighted imaging (DWI) and extensive perfusion defects were introduced and described as having a favorable outcome after intravenous thrombolysis. We sought to determine the clinical characteristics of patients with total mismatch and describe their clinical courses.

METHODS

We retrospectively analyzed subjects from the stroke registry of acute ischemic stroke patients between August 2008 and October 2009. The patients with the following characteristics were included: acute ischemic stroke within 6 hours of symptom onset, a large artery occlusion in the anterior circulation and a negative DWI but large perfusion-weighted imaging (PWI) lesion on mean transit time maps. According to our stroke imaging protocol, the patients underwent emergent MR imaging immediately after admission and follow-up imaging within 96 hours of symptom onset.

RESULTS

Four patients were identified as suitable for the imaging criteria (negative DWI and MTT delay) of this study. All patients presented with a spontaneous recovery of ischemic symptoms related to the middle cerebral artery occlusion had a potential source of cardioembolism and eventually developed new lesions on follow-up DWI and recanalization without thrombolysis.

CONCLUSION

In our study, total mismatch seems to suggest favorable outcome after recanalization, regardless of thrombolysis. Further attention should be focused on the considerable variations in PWI and DWI findings in acute stroke.