Outcome in hyperglycemic stroke with ultrasound-augmented thrombolytic therapy

Distinct thermal effect on biological tissues using subwavelength ultrasound metalens at megahertz

Ultrasound focusing plays an important role in biomedical therapy and diagnosis. Acoustic metalens has showcased remarkable focusing performance but yet to be implemented to the practical ultrasound therapeutic applications. We design a planar metalens operating at megahertz and experimentally demonstrate the distinct thermal effect on biological tissues induced by the high-resolution focusing. A prominent temperature rise of 50°C is experimentally observed in the biological phantom, with a much lower input ultrasound power of 4 W compared with the traditional methods. We further study the thermal effect on fresh porcine liver and investigate the morphological changes under different physical parameters. Visible lesions are observed in in vitro tissues at the lowest input ultrasound power of 2.6 W within 10 s. This study facilitates the practical biomedical application of acoustic metalens, providing a feasible approach for the precise, safe, and reliable therapeutic ultrasound with the simple and compact metalens.

The impact of antihypertensive use in the treatment of acute ischemic stroke in patients receiving alteplase

BACKGROUND

Treatment of acute ischemic stroke (AIS) with intravenous alteplase within 4.5 h of symptom onset is associated with neurologic improvement. High baseline blood pressure (BP) and BP variability during the first 24 h of AIS is associated with increased early adverse events and death. The purpose of this study is to characterize the incidence of poor neurologic outcome in patients treated with alteplase for AIS who received antihypertensive medications prior to and within the first 24 h following alteplase administration compared with patients who did not.

METHODS

This was a multicenter, retrospective cohort of patients >18 years diagnosed with AIS from January 1, 2011 through December 31, 2015 who received one or more antihypertensive medication in the first 24 h of AIS in patients receiving alteplase compared to controls. The primary endpoint was poor neurologic outcome at 90 days, according to modified Rankin Scale ≥3. Univariate analysis was conducted using Chi-square, Fisher's exact test, or Mann-Whitney U test. Multivariable logistic regression was conducted to determine independent predictors of poor outcome.

RESULTS

Of the 587 patients evaluated, 351 (59.7%) were included, of which 127 (36.2%) received antihypertensive(s). More patients in the antihypertensive treatment group had a history of hypertension (88.2% vs. 69.6%, p < 0.01), diabetes (37% vs. 25.5%, p = 0.03) and chronic kidney disease (19.7% vs. 8.5%, p < 0.01). Intravenous push labetalol was most commonly administered (81.2%), followed by nicardipine (44.1%), and hydralazine (22%). More patients in the antihypertensive treatment group experienced poor neurologic outcome at 90 days (53.5% vs. 38.8%, p < 0.01), however, this finding was not observed after multivariable logistic regression.

CONCLUSION

Antihypertensive treatment in the first 24 h of AIS was associated with poor neurologic outcomes at 90 days. However, after controlling for other clinical factors in a multivariable logistic regression, this association was no longer observed.

Association of Baseline Hyperglycemia With Outcomes of Patients With and Without Diabetes With Acute Ischemic Stroke Treated With Intravenous Thrombolysis: A Propensity Score-Matched Analysis From the SITS-ISTR Registry

Available data from observational studies on the association of admission hyperglycemia (aHG) with outcomes of patients with acute ischemic stroke (AIS) treated with intravenous thrombolysis (IVT) are contradictory, especially when stratified by diabetes mellitus (DM) history. We assessed the association of aHG (≥144 mg/dL) with outcomes stratified by DM history using propensity score-matched (PSM) data from the SITS-ISTR. The primary safety outcome was symptomatic intracranial hemorrhage (SICH); 3-month functional independence (FI) (modified Rankin Scale [mRS] scores 0-2) represented the primary efficacy outcome. Patients with and without aHG did not differ in baseline characteristics both in the non-DM (n = 12,318) and DM (n = 6,572) PSM subgroups. In the non-DM group, patients with aHG had lower 3-month FI rates (53.3% vs. 57.9%, P < 0.001), higher 3-month mortality rates (19.2% vs. 16.0%, P < 0.001), and similar symptomatic intracerebral hemorrhage (SICH) rates (1.7% vs. 1.8%, P = 0.563) compared with patients without aHG. Similarly, in the DM group, patients with aHG had lower rates of 3-month favorable functional outcome (mRS scores 0-1, 34.1% vs. 39.3%, P < 0.001) and FI (48.2% vs. 52.5%, P < 0.001), higher 3-month mortality rates (23.7% vs. 19.9%, P < 0.001), and similar SICH rates (2.2% vs. 2.7%, P = 0.224) compared with patients without aHG. In conclusion, aHG was associated with unfavorable 3-month clinical outcomes in patients with and without DM and AIS treated with IVT.

The silver effect of admission glucose level on excellent outcome in thrombolysed stroke patients

Higher admission glucose levels (AGL) are associated with less favorable outcome in thrombolysis. But, could AGL’s impact on outcome vary by onset-to-treatment (OTT) time? Is hyperglycemia associated with a shorter therapeutic time window for excellent outcome for thrombolysed stroke patients? We assessed predictive values of AGL, baseline NIHSS, age, and OTT time quartiles on excellent outcome (3-month modified Rankin score of 0–1) in 773 patients treated by rt-Pa. We added the AGL × OTT time quartile interaction in the model and separately analyzed the predictive values of AGL, age, and NIHSS for each OTT time quartile if the interaction was significant. AGL, baseline NIHSS, age, and OTT time quartiles were significant predictors. When added in the model, the AGL × OTT interaction was significant (OR: 0.96, 95% CI: 0.94–0.99, p: 0.0009). AGL was predictive only during the third OTT time quartile (181–224 min). During this period, the predicted rate of excellent outcome was 16% for AGL = 6.5 mmol/L and 8% for AGL = 8 mmol/L. The rate of excellent outcome was not decreased in hyperglycemic patients for OTT time ≤ 180 min (20 vs. 24.5% p: 0.37), but was decreased for OTT time > 180 min (9.6 vs. 26.7% p: 0.00001). Similar results were found in patients with MCA recanalization, but not in patients without recanalization. The therapeutic time window for excellent outcome is shortened in hyperglycemic patients. This would support the design of “freezing penumbra” randomized trials based on ultra-early AGL control.

The correlation between admission blood glucose and intravenous rt-PA-induced arterial recanalization in acute ischemic stroke: a multi-centre TCD study

BACKGROUND

The relationship between hyperglycemia and arterial recanalization following intravenous recombinant tissue-plasminogen activator treatment in acute ischemic stroke is not well understood.

AIM

We aimed to evaluate the effects of hyperglycemia in thrombolysed ischemic stroke patients on recanalization rate and clinical outcome.

METHODS

We studied 348 (231 subjects from the CLOTBUST databank and 117 subjects from the CLOTBUST trial phase II) with documented intracranial artery occlusion treated with intravenous recombinant tissue-plasminogen activator. Serum glucose was determined at baseline before intravenous recombinant tissue-plasminogen activator administration. Hyperglycemia was defined as a glucose level ≥140 mg/dl (7·7 mmol/l). Transcranial Doppler findings were interpreted using the thrombolysis in brain ischemia flow grading system as persistent arterial occlusion, re-occlusion or complete recanalization. Poor clinical outcome was defined by modified Rankin score > 2 at three-months.

RESULTS

At baseline, 138 patients (37·4%) were hyperglycemic and 210 patients (56·9%) normoglycemic. Baseline characteristics based on glucose ≥ 140 (7·7 mmol/l) or less 140: age (70·0 ± 12·4 vs. 67·3 ± 14·1, P = 0·065), baseline National Institutes of Health Stroke Scale (17·0 ± 5·5 vs. 15·8 ± 5·5, P = 0·054), time to recombinant tissue-plasminogen activator (141·4 ± 69·1 vs. 145·3 ± 48·4 mins, P = 0·56), and history of diabetes mellitus [60/138 (43·5%) vs. 22/210 (10·5%), P < 0·001]). Patients with hyperglycemia have a higher rate of persisting occlusion [72/138 (52·2%) vs. 66/210 (31·4%)] and less rate of complete recanalization [34/138 (24·6%) vs. 82/210 (39%), P < 0·001]. Median time to recanalization in patients with severe hyperglycemia (glucose ≥ 200) (11 mmol/l) and glucose <200 was 163 ± 79 and 131 ± 90 mins, respectively (P = 0·045). Sixteen patients (11·6%) in the hyperglycemic group and 12 (5·7%) in the normoglycemic group had symptomatic intracerebral hemorrhage (P = 0·049). Seventy-eight patients (69%) in the hyperglycemia group and 72 patients (41·6%) in the normoglycemic group had poor clinical outcome (three-month modified Rankin score > 2) (P ≤ 0·001). After adjusting for stroke risk factors, patients with hyperglycemia were more likely to have poor clinical outcome (three-month modified Rankin score > 2) (adjusted odds ratio = 2·22, 95% confidence interval: 1·2-4·11, P = 0·011) and low complete recanalization rate (adjusted odds ratio: 0·5, confidence interval: 0·3-0·92, P = 0·025) with trend of increase risk of symptomatic intracerebral hemorrhage (adjusted odds ratio: 2·07, confidence interval:0·8-5·1, P = 0·114). There was no association between baseline glucose as a continuous variable and poor clinical outcome, but there was with the complete recanalization's rate.

CONCLUSION

Hyperglycemia is associated with low rate of complete recanalization and poor clinical outcome in intravenous recombinant tissue-plasminogen activator-treated patients. Further studies are needed to evaluate whether lowering hyperglycemia is beneficial in the management of acute stroke patients.

Stroke and diabetes mellitus

Diabetes is a condition of accelerated vascular aging. Patients with diabetes have approximately twice the risk of stroke compared to nondiabetics. Hyperglycemia is a strong risk factor for poor outcome after stroke, but it may be simply a marker of poor outcome rather than a cause. Glucose lowering has not been shown to be associated with improved prognosis. Similarly, long-term prevention of stroke risk among diabetic patients is not improved with glucose-lowering therapies. Stroke prevention and treatment remains generic among diabetic patients. The future, however, may be brighter, with multiple new agents recently available. We await the outcome of these agents on macrovascular complications such as stroke.

CT perfusion-guided patient selection for endovascular recanalization in acute ischemic stroke: a multicenter study

BACKGROUND

The treatment of acute ischemic stroke is traditionally centered on time criteria, although recent evidence suggests that physiologic neuroimaging may be useful. In a multicenter study we evaluated the use of CT perfusion, regardless of time from symptom onset, in patients selected for intra-arterial treatment of ischemic stroke.

METHODS

Three medical centers retrospectively assessed stroke patients with a National Institute of Health Stroke Scale of ≥ 8, regardless of time from symptom onset. CT perfusion maps were qualitatively assessed. Patients with defined salvageable penumbra underwent intra-arterial revascularization of their occlusion. Functional outcome using the modified Rankin Score (mRS) was recorded.

RESULTS

Two hundred and forty-seven patients were selected to undergo intra-arterial treatment based on CT perfusion imaging. The median time from symptom onset to procedure was 6 h. Patients were divided into two groups for analysis: ≤ 8 h and >8 h from symptom onset to endovascular procedure. We found no difference in functional outcome between the two groups (42.8% and 41.9% achieved 90-day mRS ≤ 2, respectively (p=1.0), and 54.9% vs 55.4% (p=1.0) achieved 90-day mRS ≤ 3, respectively). Overall, 48 patients (19.4%) had hemorrhages, of which 20 (8.0%) were symptomatic, with no difference between the groups (p=1.0).

CONCLUSIONS

In a multicenter study, we demonstrated similar rates of good functional outcome and intracranial hemorrhage in patients with ischemic stroke when endovascular treatment was performed based on CT perfusion selection rather than time-guided selection. Our findings suggest that physiologic imaging-guided patient selection rather than time for endovascular reperfusion in ischemic stroke may be effective and safe.

Lack of association between hyperglycaemia at arrival and clinical outcomes in acute stroke patients treated with tissue plasminogen activator

RATIONALE

Hyperglycaemia is associated with adverse outcomes in some studies of acute ischaemic stroke.

AIMS

We hypothesised that in thrombolytic-treated stroke patients, hyperglycaemia would be independently associated with haemorrhagic transformation and unfavourable outcome.

DESIGN

Consecutive rt-PA-treated acute ischaemic stroke patients presenting to four emergency departments were analysed. Associations of initial blood glucose and survival to hospital discharge, symptomatic intracerebral haemorrhage, any form of intracerebral haemorrhage, and disability at hospital discharge were determined. Potentially confounding factors of age, National Institutes of Health Stroke Scale, and smoking were analysed by univariate logistic regression and those with P<0.3 included in the multivariate model.

STUDY OUTCOME

In 268 patients, initial glucose values ranged from 62 to 507 mg/dl (mean 131). Elevated glucose at arrival was not significantly associated with any adverse clinical outcomes. A trend towards higher mortality in hyperglycaemic patients (odds ratio 1.71 per 100 mg/dl increase in glucose, 95% confidence interval 0.92-3.13, P=0.08) was seen, but is of unclear significance, and was not corroborated by effects on discharge disability, symptomatic intracerebral haemorrhage or intracerebral haemorrhage.

CONCLUSIONS

Thrombolytic-treated stroke patients with hyperglycaemia at presentation did not have significantly worse outcomes than others in this cohort. These data fail to confirm previously described associations seen in similarly sized studies. Further study of these associations and their magnitude are necessary to better define the relationship between serum glucose and outcome in thrombolytic-treated acute ischaemic stroke.

Treatment of hyperglycemia in ischemic stroke (THIS): a randomized pilot trial

BACKGROUND AND PURPOSE

Hyperglycemia may worsen brain injury during acute cerebral infarction. We tested the feasibility and tolerability of aggressive hyperglycemia correction with intravenous insulin compared with usual care during acute cerebral infarction.

METHODS

We conducted a randomized, multicenter, blinded pilot trial for patients with cerebral infarction within 12 hours after onset, a baseline glucose value >or=8.3 mmol/L (>or=150 mg/dL), and a National Institutes of Health Stroke Scale score of 3 to 22. Patients were randomized 2:1 to aggressive treatment with continuous intravenous insulin or subcutaneous insulin QID as needed (usual care). Target glucose levels were <7.2 mmol/L (<130 mg/dL) in the aggressive-treatment group and <11.1 mmol/L (<200 mg/dL) in the usual-care group. Glucose was monitored every 1 to 2 hours, and the protocol treatments continued for up to 72 hours. Final clinical outcomes were assessed at 3 months.

RESULTS

We randomized 46 patients (31 to aggressive treatment and 15 to usual care). All patients in the aggressive-treatment group and 11 (73%) in the usual-care group had diabetes (P=0.008). Glucose levels were significantly lower in the aggressive-treatment group throughout protocol treatment (7.4 vs 10.5 mmol/L [133 vs 190 mg/dL], P<0.001). Hypoglycemia <3.3 mmol/L (<60 mg/dL) occurred only in the aggressive-treatment group (11 patients, 35%), 4 (13%) of whom had brief symptoms, including only 1 (3%) neurologic. Final clinical outcomes were nonsignificantly better in the aggressive-treatment group.

CONCLUSIONS

The intravenous insulin protocol corrected hyperglycemia during acute cerebral infarction significantly better than usual care without major adverse events and should be investigated in a clinical efficacy trial.