Response by Mulder et al to Letter Regarding Article, "Baseline Blood Pressure Effect on the Benefit and Safety of Intra-Arterial Treatment in MR CLEAN (Multicenter Randomized Clinical Trial of Endovascular Treatment of Acute Ischemic Stroke in the Netherlands)"

Baseline Blood Pressure Was Associated with Hemispheric Cerebral Blood Flow in Acute Small Subcortical Infarcts

INTRODUCTION

While increased baseline blood pressure (BP) is a prevalent comorbidity in the acute phase of ischemic stroke, the association between baseline BP and the state of hemispheric perfusion in patients with acute small subcortical infarcts (SSIs) has not been studied in detail. The aim of this study was to investigate the relationship between baseline BP and hemispheric cerebral blood flow (CBF) in acute SSIs.

METHODS

This retrospective study included 101 patients with acute SSIs. Baseline hemispheric CBF was assessed through co-registration of baseline CT perfusion imaging and follow-up diffusion-weighted imaging. The association between baseline BP, CBF, and different cerebral small vessel disease (CSVD) biomarkers was assessed.

RESULTS

Baseline systolic BP (SBP) and diastolic BP (DBP) were negatively associated with contralateral hemispheric CBF after multivariate-adjusted linear analysis (SBP: β = -0.001, 95% CI: -0.002 to 0.000, p = 0.030; DBP: β = -0.002, 95% CI: -0.003∼0.001, p = 0.006). Among other CSVD biomarkers, the presence of any cerebral microbleeds showed a significant association with lower CBF in the contralateral hemisphere of the infarct lesion (r = -0.270, p = 0.035).

CONCLUSION

In patients with acute SSIs, increased baseline BP was associated with reduced CBF in the contralateral hemisphere of the infarct lesion, which probably could be interpreted by the exacerbation of the CSVD burden, suggesting a potential mechanistic link between BP autoregulation dysfunction and the aggravation of neurovascular impairment in SSIs.

Efficacy of Early Intensive Blood Pressure Management After Thrombectomy: Protocol for a Randomized Controlled Clinical Trial (IDENTIFY)

BACKGROUND

The optimal strategy for blood pressure management after thrombectomy remains unknown. The primary objective of The Early Intensive Blood Pressure Management after Endovascular Thrombectomy (IDENTIFY) study is to explore the efficacy and safety of early intensive blood pressure management strategies after thrombectomy compared with that of standard management.

METHODS

The IDENTIFY study is a prospective, randomized, open-label, assessor-blinded multicenter clinical trial. Patients with acute anterior circulation ischaemic stroke who underwent endovascular thrombectomy within 6 h of stroke onset, achieved successful recanalization, and had two consecutive blood pressure readings > 130 mm Hg during the first 6 h after thrombectomy will be enrolled and centrally randomized into intensive or standard management groups in a 1:1 ratio. Continuous blood pressure monitoring will be initiated at the end of thrombectomy, and patients with high blood pressure during the transfer to the wards will also be enrolled. For patients in the intensive management group, the target blood pressure will be < 130 mm Hg, and the use of antihypertensive drugs will be discontinued if systolic blood pressure goes below 110 mm Hg. The target blood pressure for the standard management group will be < 180 mm Hg, and if systolic blood pressure decreases below 140 mm Hg, the use of antihypertensive drugs will be stepwise decreased until the systolic blood pressure reaches 140 mm Hg again or the infusion is discontinued. Patients will have their blood pressure reduced to the target range within 1 h from randomization and maintained until 24 h after thrombectomy with intravenous hypertensive drugs. A sample size of 600 was predicted. The primary outcome will be the rate of dependency (modified Rankin Scale scores 3-6) at 90 days. Secondary outcomes will include intracerebral hemorrhage (either symptomatic or asymptomatic) within 24 h and 7 days, malignant brain oedema, all-cause death, death and severe disability at 90 days, and quality of life at 90 days, which will be measured using the EuroQol-5 Dimensions-5 Level (EQ-5D-5L) and the 36-Item Short Form Health Survey (SF-36). Safety outcomes will include stroke recurrence within 24 h, early neurological deterioration, hypotension within 24 h, death within 7 days after endovascular thrombectomy, and all-cause acute kidney injury. Trial registration chictr.org.cn (identifier: ChiCTR2200057770). Registered March 17, 2022, http://www.chictr.org.cn/edit.aspx?pid=162575&htm=4.

Intracranial Hemorrhage After Reperfusion Therapies in Acute Ischemic Stroke Patients

Reperfusion therapies are the mainstay of acute ischemic stroke (AIS) treatments and overall improve functional outcome. Among the established complications of intravenous (IV) tissue-type plasminogen activator (tPA), intracranial hemorrhage (ICH) is by far the most feared and has been extensively described by seminal works over the last two decades. Indeed, IV tPA is associated with increased odds of any ICH and symptomatic ICH responsible for increased mortality rate during the first week after an AIS. Despite these results, IV tPA has been found beneficial in several pioneering randomized trials and improves functional outcome at 3 months. Endovascular therapy (EVT) combined with IV tPA for AIS patients consecutive to an anterior circulation large-vessel occlusion does not increase ICH occurrence. Of note, EVT following IV tPA leads to significantly higher rates of early reperfusion than with IV tPA alone, with no difference in ICH, which challenges the paradigm of reperfusion as a major prognostic factor for ICH complications. However, several blood biomarkers (glycemia, platelet and neutrophil count), clinical factors (age, AIS severity, blood pressure management, diabetes mellitus), and neuroradiological factors (cerebral microbleeds, infarct size) have been identified as risk factors for ICH after reperfusion therapy. In the years to come, the ultimate goal will be to further improve either reperfusion rates and functional outcome, while reducing hemorrhagic complications. To this end, various approaches being investigated are discussed in this review, such as blood-pressure control after reperfusion or the use of new antiplatelet agents as an adjunct to IV tPA and exhibit reduced hemorrhagic potential during the early phase of AIS.

Association of Blood Pressure at Successful Recanalization and Parenchymal Hemorrhage After Mechanical Thrombectomy With General Anesthesia

Background: This study aims to investigate the association between blood pressure (BP) at the time of recanalization and hemorrhagic transformation in large vessel occlusion (LVO) patients following mechanical thrombectomy (MT) with general anesthesia.

Methods: We retrospectively reviewed our data base for patients with acute ischemic stroke acute ischemic stroke (AIS) who received MT between January 2018 and December 2019. The BP at two adjacent time points immediately after successful recanalization was recorded for subsequent calculation of mean BP (BP_mean), maximum BP (BP_max), minimum BP (BP_min), range of BP (BP_range), and standard deviation of SP (BP_SD). Hemorrhagic transformation was identified on 24-h computerized tomography images according to the European Cooperative Acute Stroke Study (ECASS) III trial. We used binary logistic regression analysis to investigate the association of BP parameters and the incidence of parenchymal hemorrhage (PH) and PH-2.

Results: A total of 124 patients with anterior circulation LVO were finally included for analyses. After controlling for intravenous thrombolysis, procedure duration of mechanical thrombectomy, baseline National institutes of Health Stroke Scale (NIHSS), baseline ASPECTS, and number of device passes, the results showed that every increment of 10 mmHg in SBP_range (OR 1.559; 95% CI 1.027–2.365; P = 0.037) and SBP_SD (OR 1.998; 95% CI 1.017–3.925; P = 0.045) were independently associated with PH. After adjustment for intravenous thrombolysis, procedure duration of mechanical thrombectomy, baseline NIHSS, the results showed that every increment of 10 mmHg in SBP_mean (OR 1.973; 95% CI 1.190–3.271; P = 0.008), SBP_max (OR 1.838; 95% CI 1.199 to 2.815; P = 0.005), SBP_range (OR 1.908; 95% CI 1.161–3.136; P = 0.011) and SBP_SD (OR 2.573; 95% CI 1.170–5.675; P = 0.019) were independently associated with PH-2.

Conclusion: Patients with higher systolic BP and variability at the time of successful recanalization were more likely to have PH-2 in LVO patients following MT with general anesthesia.

Blood Pressure Target in Acute Stroke to Reduce HemorrhaGe After Endovascular Therapy: The Randomized BP TARGET Study Protocol

Background: High systolic blood pressure (BP) is associated with an increased risk of intracranial hemorrhage (ICH) in patients undergoing reperfusion therapy. However, there are no data from randomized trials to guide BP management after reperfusion following endovascular therapy (EVT) for patients with acute ischemic stroke (AIS) with large vessel occlusion (LVO). The objective is to evaluate if BP control with a target of 100-129 mmHg systolic BP ("tight" SBP control) can reduce ICH as compared to 130-185 mmHg ("usual" SBP control) in AIS participants after reperfusion by EVT. Methods: The BP TARGET trial is a multicenter, prospective, randomized, controlled, open-label, blinded endpoint clinical trial. AIS participants with LVO experiencing successful reperfusion are randomly assigned, in a 1:1 ratio, to have a "tight" SBP control (100-129 mmHg) or a conservative SBP control (130-185 mmHg) during the following 24-36 h. The primary outcome is the rate of ICH (either symptomatic or asymptomatic) on follow-up CT scan at 24-36 h. Secondary outcomes include the rate of the symptomatic ICH, the overall distribution of the modified Rankin Scale (mRS) at 90 days, favorable outcome (90-day mRs 0-2), infarct volume at follow-up CT scan at 24-36 h, change in National Institute of Health Stroke Scale at 24 h, and all-cause mortality at 90 days. Conclusion: This is the first randomized trial directly comparing the efficacy of different SBP targets after EVT reperfusion. This prospective trial aims to determine whether a "tight" SBP control after EVT reperfusion can reduce the risk of ICH.