Management of Acute Hypertensive Response in Patients With Ischemic Stroke

Embolic occlusion of internal carotid artery in conscious rats: Immediate effects of cerebral ischemia

In most preclinical models of focal ischemic stroke, vascular occlusion is performed under general anesthesia. However, anesthetic agents exert confounding effects on mean arterial blood pressure (MABP), cerebrovascular tone, oxygen demand, and neurotransmitter receptor transduction. Moreover, the majority of studies do not use a blood clot, which more fully models embolic stroke. Here, we developed a blood clot injection model to produce large cerebral artery ischemia in unanesthetized rats. Under isoflurane anesthesia, an indwelling catheter was implanted in the internal carotid artery via a common carotid arteriotomy and preloaded with a 0.38-mm-diameter clot of 1.5, 3, or 6 cm length. After discontinuing anesthesia, the rat was returned to a home cage where it regained normal mobility, grooming, eating activity, and a stable recovery of MABP. One hour later, the clot was injected over a 10-s period and the rats were observed for 24 h. Clot injection produced a brief period of irritability, then 15-20 min of complete inactivity, followed by lethargic activity at 20-40 min, ipsilateral deviation of the head and neck at 1-2 h, and limb weakness and circling at 2-4 h. Neurologic deficits, elevated MABP, infarct volume, and increased hemisphere water content varied directly with clot size. Mortality after 6-cm clot injection (53%) was greater than that after 1.5-cm (10%) or 3-cm (20%) injection. Combined non-survivor groups had the greatest MABP, infarct volume, and water content. Among all groups, the pressor response correlated with infarct volume. The coefficient of variation of infarct volume with the 3-cm clot was less than that in published studies with the filament or standard clot models, and therefore may provide stronger statistical power for stroke translational studies. The more severe outcomes from the 6-cm clot model may be useful for the study of malignant stroke.

Predicting prognosis in patients with stroke treated with intravenous alteplase through the 24-h trajectory of blood pressure changes

Blood pressure (BP) monitored within 24 h from the beginning of intravenous thrombolysis (IVT) with alteplase, is one of the important factors affecting the prognosis of patients with acute ischemic stroke (AIS). This study aimed to explore longitudinal BP trajectory patterns and determine their association with stroke prognosis after thrombolysis. From November 2018 to September 2019, a total of 391 patients were enrolled consecutively during the study period, and 353 patients were ultimately analyzed. Five systolic (SBP) and four diastolic blood pressure (DBP) trajectory subgroups were identified. The regression analysis showed that when compared with the rapidly moderate stable group, the continuous fluctuation‐very high level SBP group (odds ratio [OR]: 2.743, 95% confidence interval [CI]: 1.008–7.467) was associated with early neurological deterioration (END). Both the rapid drop‐high level SBP (OR: 0.448, 95% CI: 0.219–0.919) and DBP groups (OR: 0.399, 95% CI: 0.219–0.727) were associated with early neurological improvement (ENI). Moreover, there was a U‐shaped correlation between the OR value of SBP trajectory group and favorable outcome (the modified Rankin Scale [mRS] score 0–2) at 3 months: the slow drop‐low level SBP group represent a well‐established unfavorable outcome risk factor (OR:5.239, 95% CI: 1.271–21.595), and extremely high SBP—the continuous fluctuation‐very high level SBP group, are equally associated with elevated unfavorable outcome risk (OR:3.797, 95% CI: 1.486–9.697). The continuous fluctuation‐very high level DBP group was statistically significant in mRS (OR: 3.387, CI: 1.185–9.683). The BP trajectory groups show varying clinical features and risk of neurological dysfunction. The findings may help identify potential candidates for clinical BP monitoring, control, and specialized care.

Optimal blood pressure levels in different phases of peripheral thrombolysis period in acute ischemic stroke

BACKGROUND

Dramatic changes of blood pressure (BP) were observed in the peripheral thrombolysis period, however, there is no consensus about BP control targets in the different phases.

METHODS

We retrospectively studied a consecutive sample of 510 patients treated with intravenous thrombolysis and followed-up for 3 months. The peripheral thrombolysis period was divided into these phases: Phase 1 (from onset to thrombolysis), Phase 2 (thrombolysis), Phase 3 (from thrombolysis to 24 h after thrombolysis), and Phase 4 (from 24 h to 7 days after thrombolysis). Patients were divided into quintiles according to mean blood pressure in these phases, respectively. Neurological improvement was evaluated using the modified Rankin Scale score at 3-month after thrombolysis.

RESULTS

Lower risk of intracerebral hemorrhage within 7 days was found in lower quintiles of SBP (OR = 0.100, 95% CI 0.011-0.887, P = 0.039 in Phase 1 quintile Q1, OR = 0.110, 95% CI 0.012-0.974, P = 0.047 in Phase 2-3 quintile Q1, and OR, 0.175, 95% CI, 0.035-0.872; P = 0.033 in Phase 4 quintile Q2, respectively). Better neurological improvement was found in SBP quintiles: Q2-Q4 (127.3-155.7 mmHg) in Phase 4 (OR = 3.095, 95% CI 1.524-6.286, P = 0.002 for Q2; OR = 2.697, 95% CI 1.354-5.370, P = 0.005 for Q3; and OR = 2.491, 95% CI 1.263-4.913, P = 0.008 for Q4, respectively). Our results also showed higher average real variability of SBP was negatively associated with better neurological outcome in Phase 1 and Phase 2-3.

CONCLUSIONS

Maintaining SBP levels (≤148 mmHg) from admission to the first 24 h after thrombolysis, then keeping SBP levels (127-138 mmHg) would be beneficial.

Impact of aging and comorbidities on ischemic stroke outcomes in preclinical animal models: A translational perspective

Ischemic stroke is a highly complex and devastating neurological disease. The sudden loss of blood flow to a brain region due to an ischemic insult leads to severe damage to that area resulting in the formation of an infarcted tissue, also known as the ischemic core. This is surrounded by the peri-infarct region or penumbra that denotes the functionally impaired but potentially salvageable tissue. Thus, the penumbral tissue is the main target for the development of neuroprotective strategies to minimize the extent of ischemic brain damage by timely therapeutic intervention. Given the limitations of reperfusion therapies with recombinant tissue plasminogen activator or mechanical thrombectomy, there is high enthusiasm to combine reperfusion therapy with neuroprotective strategies to further reduce the progression of ischemic brain injury. Till date, a large number of candidate neuroprotective drugs have been identified as potential therapies based on highly promising results from studies in rodent ischemic stroke models. However, none of these interventions have shown therapeutic benefits in stroke patients in clinical trials. In this review article, we discussed the urgent need to utilize preclinical models of ischemic stroke that more accurately mimic the clinical conditions in stroke patients by incorporating aged animals and animal stroke models with comorbidities. We also outlined the recent findings that highlight the significant differences in stroke outcome between young and aged animals, and how major comorbid conditions such as hypertension, diabetes, obesity and hyperlipidemia dramatically increase the vulnerability of the brain to ischemic damage that eventually results in worse functional outcomes. It is evident from these earlier studies that including animal models of aging and comorbidities during the early stages of drug development could facilitate the identification of neuroprotective strategies with high likelihood of success in stroke clinical trials.

Trajectory Groups of 24-Hour Systolic Blood Pressure After Acute Ischemic Stroke and Recurrent Vascular Events

Background and Purpose- Blood pressure dynamics in patients with acute ischemic stroke may serve as an important modifiable and prognostic factor. Methods- A total of 8376 patients with acute ischemic stroke were studied from a prospective multicenter registry. Patients were eligible if they had been admitted within 24 hours of symptom onset and had ≥5 systolic blood pressure (SBP) measurements during the first 24 hours of hospitalization. SBP trajectory groups in the first 24 hours were identified using the TRAJ procedure in SAS software with delta-Bayesian Information Criterion and prespecified modeling parameters. Vascular events, including recurrent stroke, myocardial infarction, and death, were prospectively collected. The risk of having vascular events was calculated using the frailty model to adjust for clustering by hospital. Results- The group-based trajectory model classified patients with acute ischemic stroke into 5 SBP trajectory groups: low (22.3%), moderate (40.8%), rapidly stabilized (11.9%), acutely elevated (18.5%), and persistently high (6.4%) SBP. The risk of having vascular events was increased in the acutely elevated (hazard ratio, 1.28 [95% confidence interval, 1.12-1.47]) and the persistently high SBP groups (hazard ratio, 1.67 [95% confidence interval, 1.37-2.04]) but not in the rapidly stabilized group (hazard ratio, 1.13 [95% confidence interval, 0.95-1.34]), when compared with the moderate SBP group. Conclusions- SBP during the first 24 hours after acute ischemic stroke may be categorized into distinct trajectory groups, which differ in relation to stroke characteristics and frequency of subsequent recurrent vascular event risks. The findings may help to recognize potential candidates for future blood pressure control trials.

Cutting Edge Acute Ischemic Stroke Management

Acute ischemic stroke (AIS) is a medical emergency that requires prompt recognition and streamlined work-up to ensure that time-dependent therapies are initiated to achieve the best outcomes. This article discusses frequently missed AIS in the emergency department, the role of various imagining modalities in the work-up of AIS, updates on the use of intravenous thrombolytics and endovascular therapy for AIS, pearls on supportive care management of AIS, and prehospital and hospital process improvements to shorten door-to-needle time.

The influence of mean arterial pressure on the efficacy and safety of dual antiplatelet therapy in minor stroke or transient ischemic attack patients

Mean arterial pressure (MAP) is the strongest predictor of stroke. The combination of clopidogrel and aspirin within 24 hours after onset has been suggested by the Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events (CHANCE) study to be superior to aspirin alone. However, it is not clear whether poststroke blood pressure has an influence on the efficacy and safety of dual antiplatelet treatment. We have performed a post hoc analysis from the CHANCE trial. Patients were stratified into three groups based on MAP levels. Among patients with MAP <102 mm Hg, there was no significant difference in stroke recurrence between the clopidogrel-aspirin group and the aspirin group (7.7% vs 7.5%; hazard ratio [HR], 1.03; 95% confidence interval [CI], 0.73-1.45). However, compared to aspirin treatment, the clopidogrel-aspirin dual treatment was more effective at reducing the risk of stroke in patients with MAP ≥113 mm Hg (6.9% vs 12.3%, HR, 0.55; 95% CI, 0.39-0.78) or 102-113 mm Hg (9.5% vs 14.9%, HR, 0.62; 95% CI, 0.48-0.81). There was a significant interaction between MAP and antiplatelet therapy as it relates to stroke recurrence (P for interaction = 0.037), and a similar result was found for combined vascular events (P for interaction = 0.027). In conclusion, dual antiplatelet therapy may be more effective at reducing combined vascular events in patients with higher MAP after minor stroke or transient ischemic attack.

Early Neurological Deterioration after Recanalization Treatment in Patients with Acute Ischemic Stroke: A Retrospective Study

Background:

Early neurological deterioration (END) is a prominent issue after recanalization treatment. However, few studies have reported the characteristics of END after endovascular treatment (EVT) as so far. This study investigated the incidence, composition, and outcomes of END after intravenous recombinant tissue plasminogen activator (IV rt-PA) and EVT of acute ischemic stroke, and identified risk factors for END.

Methods:

Medical records of patients who received recanalization treatment between January 1, 2014, and December 31, 2015 were reviewed. Patients were classified into IV rt-PA or EVT group according to the methods of recanalization treatment. The END was defined as an increase in the National Institutes of Health Stroke Scale (NIHSS) ≥4 or an increase in Ia of NIHSS ≥1 within 72 h after recanalization treatment. Clinical data were compared between the END and non-END subgroups within each recanalization group.

Results:

Of the 278 patients included in the study, the incidence of END was 34.2%. The incidence rates of END were 29.8% in the IV rt-PA group and 40.2% in the EVT group. Ischemia progression (68.4%) was the main contributor to END followed by vasogenic cerebral edema (21.1%) and symptomatic intracranial hemorrhage (10.5%). Multivariate logistic regression showed that admission systolic blood pressure (SBP) ≥160 mmHg (odds ratio [OR]: 2.312, 95% confidence interval [CI]: 1.105–4.837) and large artery occlusion after IV rt-PA (OR: 3.628, 95% CI: 1.482–8.881) independently predicted END after IV rt-PA; and admission SBP ≥140 mmHg (OR: 5.183, 95% CI: 1.967–13.661), partial recanalization (OR: 4.791, 95% CI: 1.749–13.121), and nonrecanalization (OR: 5.952, 95% CI: 1.841–19.243) independently predicted END after EVT. The mortality rate and grave outcome rate at discharge of all the END patients (26.3% and 55.8%) were higher than those of all the non-END patients (1.1% and 18.6%; P < 0.01).

Conclusions:

END was not an uncommon event and associated with death and grave outcome at discharge. High admission SBP and unsatisfactory recanalization of occluded arteries might predict END.

Blood Pressure Goals in Acute Stroke-How Low Do You Go?

PURPOSE OF REVIEW

Elevations in systolic blood pressure (BP) greater than 140 mmHg are reported in the majority (75%) of patients with acute ischemic stroke and in 80% of patients with acute intracerebral hemorrhages (ICH). This paper summarizes and updates the current knowledge regarding the proper management strategy for elevated BP in patients with acute stroke. Recent studies have generally showed a neutral effect of BP reduction on clinical outcomes among acute ischemic stroke patients. Thus, because of the lack of convincing evidence from clinical trials, aggressive BP reduction in patients presenting with acute ischemic stroke is currently not recommended. Although in patients treated with intravenous tissue plasminogen activator, guidelines are recommending BP < 180/105 mmHg but currently, the optimal BP management after reperfusion therapy still remains unclear. In acute ICH, the evidence from randomized clinical trials supports the immediate BP lowering targeting systolic BP to 140 mmHg, which is now recommended by guidelines.

Controlling Hypertension After Severe Cerebrovascular Event (CHASE): study protocol for a randomized controlled trial

Background

No ideal blood pressure (BP) range has been scientifically determined for acute stroke, and no studies on BP management have been carried out for patients with severe stroke. This trial aims to investigate whether individualized lowering of elevated BP would improve the outcome in patients with severe stroke.

Methods/design

The CHASE trial is a multicenter, randomized, controlled study. A total of 500 adult patients with acute severe stroke will be enrolled in 18 study sites in China and randomized to individualized BP lowering (10–15% reduction from admission level) or guideline-recommended BP lowering. The primary outcome measurement is the proportion of participants with a poor outcome (modified Rankin Scale ≥ 3) at day 90 of enrollment. Secondary outcomes include disability at hospital discharge and the ability of activities of daily living at day 90 of enrollment. The relationship between intervention and the primary outcome will be analyzed using multivariate logistic regression adjusted for study site, demographics, and baseline characteristics.

Discussion

The CHASE trial will be the first study to explore the optimum BP management for acute severe stroke. This trial potentially offers a strong argument for individualized target for lowering elevated BP in patients with severe stroke.

Trial registration

ClinicalTrials.gov, NCT02982655. Registered on 30 November 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2530-x) contains supplementary material, which is available to authorized users.

Relationship between Post-Thrombolysis Blood Pressure and Outcome in Acute Ischemic Stroke Patients Undergoing Thrombolysis Therapy

BACKGROUND

The management of blood pressure (BP) for acute ischemic stroke (AIS) patients undergoing thrombolysis is still under debate. The purpose of this study was (1) to explore the association between post-thrombolysis BP and functional outcome and (2) to examine whether post-thrombolysis BP can predict functional outcome in Chinese AIS patients undergoing thrombolysis therapy.

METHODS

From December 2012 to November 2016, AIS patients undergoing thrombolysis were reviewed retrospectively in the Department of Neurology at Xuanwu Hospital. The BP levels were measured before and immediately after thrombolysis. Clinical outcomes, which comprised favorable outcome (modified Rankin Scale score 0-2) and unfavorable outcome (modified Rankin Scale score 3-6) at 3 months, were analyzed by logistic regression model. A receiver operating characteristic curve was used to evaluate the predictive value of post-thrombolysis BP.

RESULTS

Patients with unfavorable outcome at 3 months had a higher post-thrombolysis systolic BP than those with favorable outcome (P = .015). Multivariate analysis showed that post-thrombolysis systolic BP below 159.5 mm Hg was associated with favorable outcome. According to the receiver operating characteristic curve, post-thrombolysis systolic BP was a predictor of functional outcome with an area under the curve of .573 (95% confidence interval = .504-.642).

CONCLUSIONS

Our study indicated that post-thrombolysis systolic BP is a predictor of functional outcome for Chinese AIS patients undergoing thrombolysis therapy. It is reasonable for AIS patients to keep post-thrombolysis systolic BP below 159.5 mm Hg to obtain a favorable outcome.