After intravascular treatment, can intensive blood pressure reduce cerebral parenchymal hemorrhage?

Although endovascular treatment has shown great curative effect for patients with acute ischemic stroke, the recanalization rate can reach more than 80%, but more than half of the patients will experience functional impairment after surgery.

The biggest challenge in acute ischemic stroke research is mainly ischemia-reperfusion injury, including blood-brain barrier destruction, cerebral edema and cerebral parenchymal hemorrhage.

As the later analysis of the MR CLEAN trial showed, 46% of patients with acute ischemic stroke developed cerebral hemorrhage after receiving endovascular treatment.

Although patients with cerebral parenchymal hemorrhage have no obvious symptoms, this may be related to impaired function.

This mechanism can explain to a certain extent why most patients who are reperfused after endovascular treatment still have disabilities.

Yimaitong compiles and organizes, please do not reprint without authorization.

Research background The higher systolic blood pressure after endovascular treatment of acute ischemic stroke increases the risk of cerebral parenchymal hemorrhage.

However, there are currently no randomized controlled trials that can be used to guide the best blood pressure management.

Therefore, in order to evaluate whether enhanced systolic blood pressure can reduce the incidence of cerebral parenchymal hemorrhage compared with the standard systolic blood pressure target, the team of Professor Mikael Mazighi from the United States focused on the safety of enhanced blood pressure reduction after endovascular treatment of acute ischemic stroke A multi-center, open-ended randomized controlled trial was conducted on sex and effectiveness.

Research methods Researchers conducted this multi-center, open-ended randomized controlled trial in four academic medical centers in France.

Inclusion criteria: Patients aged ≥18 years, who had an acute ischemic stroke due to large blood vessel occlusion, and successfully underwent endovascular treatment.

Patients were randomly assigned (1:1) to the enhanced systolic blood pressure target group (100-129 mmHg) or the standard systolic blood pressure target group (130-185 mmHg), through a network-based central program, and passed through the center before endovascular treatment Stratified treatment with intravenous thrombolysis.

Both groups must reach the target systolic blood pressure within 1 hour after randomization, and maintain it for 24 hours through intravenous antihypertensive treatment.

The main outcome of the study was to observe the incidence of cerebral parenchymal hemorrhage within 24-36h after surgery, and the safety outcome was to observe the occurrence of hypotension.

 Research results ➤ From June 21, 2017 to September 27, 2019, 236 (74%) of the 318 patients admitted to 4 stroke centers had initially isolated middle cerebral artery occlusion.

Among the 318 patients with complete reperfusion, 172 (54%) required immediate reperfusion.
The median delay time in the enhanced systolic blood pressure target group was 285 min (IQR 234-357), and the standard systolic blood pressure target group was 297 min ( 220-353).

 ➤During reperfusion, the average systolic blood pressure in the target group of enhanced systolic blood pressure was 155mmHg (SD 26), and the average systolic blood pressure of the target group of standard systolic blood pressure was 152mmHg (25).

Within 24 hours of reperfusion, the median number of systolic blood pressure measurements was 33 (IQR 30-35), the average systolic blood pressure of the enhanced systolic blood pressure target group was 128 mmHg (SD 11), and the average systolic blood pressure of the standard systolic blood pressure target group The pressure is 138mmHg (17).

At 24 hours after reperfusion, 128 (83%) of the 154 patients in the intensive target group used antihypertensive drugs, and 31 (20%) of 159 patients in the standard target group used antihypertensive drugs.

The most frequently used drugs are calcium channel blockers.

 ➤Main outcome: 24-36h after perfusion, 65 out of 154 patients (42%) in the enhanced systolic blood pressure target group indicated cerebral parenchymal hemorrhage by CT, and 68 out of 157 patients in the standard systolic blood pressure target group (43%) CT Prompt cerebral parenchymal hemorrhage (AOR 0.
96, 95% CI: 0.
60-1.
51).

The corresponding risk difference is -1.
1% (95%CI: -11.
6-10.
1).

Symptomatic intraparenchymal hemorrhage in the enhanced systolic blood pressure target group was 17 cases (11%), the standard systolic blood pressure target group was 11 cases (7%); the type II cerebral parenchymal hemorrhage in the enhanced systolic blood pressure target group was 15 cases (10%) , The standard systolic blood pressure target group was 12 cases (8%); the all-cause mortality rate was 32 cases (21%) out of 152 cases in the enhanced systolic blood pressure target group, and 24 cases (16%) out of 153 cases in the standard systolic blood pressure target group .

The stroke score (NIHSS score), functional independence score (MRS score 0~2) or good prognosis score (MRS score 0~1) from admission to 24 hours were not statistically different between the two groups.

There was no difference in the distribution of MRS scores between the two groups after 3 months: for every 1 point increase in the score, the AOR was 0.
86 (95%CI: 0.
57-1.
28).

 Research conclusions BP-TARGET is the first randomized controlled trial specifically designed to evaluate the systolic blood pressure target after reperfusion in the endovascular treatment of acute ischemic stroke.

The results of BP-TARGET are inconsistent with the results of previous observational studies.
Previous studies have shown that increased systolic blood pressure is associated with poor functional outcomes or cerebral parenchymal hemorrhage; and this study found that in acute ischemic stroke and anterior circulation Among patients with vascular occlusion and those who successfully recanalized after endovascular treatment, the target of enhancing the systolic blood pressure of 100-129mmHg does not reduce the occurrence of cerebral parenchymal hemorrhage 24-36h after reperfusion.

And this conclusion remains consistent in the subgroups of age, occlusion site, and intravenous thrombolysis.

At the same time, this discovery also opens the way for future research to determine whether maintaining a stable blood pressure can successfully prevent the occurrence of cerebral parenchymal hemorrhage after endovascular treatment, rather than just considering a single target value of systolic blood pressure.

Yimaitong compiled and compiled from: Mazighi M, Richard S, Lapergue B, et al.
Safety and efficacy of intensive blood pressure lowering after successful endovascular therapy in acute ischaemic stroke (BP-TARGET): a multicentre, open-label, randomised controlled trial[J].
Lancet Neurol, 2021,20(4):265-274.