Among patients undergoing endovascular therapy for acute ischemic stroke, mean arterial BP of less than 70 mm Hg for more than 10 minutes and more than 90 mm Hg for more than 45 minutes were associated with poor neurologic outcomes, according to research published in JAMA Neurology.
In a cohort of 365 patients with anterior-circulation acute ischemic stroke who received endovascular therapy (mean age, 71 years; 45% women; median NIH stroke scale score, 17), researchers found that mean arterial BP thresholds associated with higher modified Rankin Scale scores at 90 days were:
- a cumulated period of at least 10 minutes with less than 70 mm Hg mean arterial BP (adjusted OR = 1.51; 95% CI, 1.02-2.22) with a number needed to harm of 10;
- a continuous period of at least 20 minutes with less than 70 mm Hg mean arterial BP (aOR = 2.3; 95% CI, 1.11-4.75); number needed to harm of 4;
- a cumulated period of at least 45 minutes with greater than 90 mm Hg mean arterial BP (aOR = 1.49; 95% CI, 1.11-2.02) with a number needed to harm of 10; and
- a continuous episode of at least 115 minutes with greater than 90 mm Hg mean arterial BP (aOR = 1.89; 95% CI, 1.01-3.54) with a number needed to harm of 6.
“Strict BP management protocols should be applied and followed by meticulous attention to BP during the endovascular therapy procedure,” Mads Rasmussen, MD, PhD, associate professor in the department of anesthesia, section of neuroanesthesia at Aarhus University Hospital, Denmark, told Healio. “Here, our data suggest that mean arterial BP should preferably be maintained within narrow limits of 70 mm Hg to 90 mm Hg.”
Anesthesia and functional outcomes
In other findings, compared with those who underwent procedural sedation (50%), procedure mean arterial BP was lower in patients who had general anesthesia (50%).
Moreover, the number of patients with mean arterial BP greater than 90 mm Hg was higher in the general anesthesia group, according to the study. The procedural sedation group tended to have longer continuous episodes with mean arterial BP greater than 110 mm Hg compared with the general anesthesia group.
“General anesthesia is often associated with hypotension, whereas procedural sedation is typically associated with more stable hemodynamics. Recent data from our group indicate that general anesthesia is associated with improved functional outcome compared to conscious sedation,” Rasmussen said in an interview. “The use of strict BP protocols may partly explain these findings. Thus, we still need to establish whether the influence of the anesthesia method on outcome is specifically related to anesthetic strategy (general anesthesia vs. procedural sedation/local anesthesia only) or strict attention to hemodynamic management.”
In the retrospective cohort study, researchers assessed patients who were enrolled into randomized clinical trials assessing anesthetic strategy for endovascular therapy between February 2014 and February 2017 and were followed up for 90 days. Researchers aimed to study the association between procedural BP parameters and neurologic outcomes after endovascular therapy.
“The findings suggest that the well-known U-shaped association between BP and outcome in patients with ischemic stroke also exists for the association of changes in BP during endovascular therapy and functional outcome,” Rasmussen told Healio. “Here, it is important to mention that the endovascular therapy procedure only represents a relatively short period of time in the overall time period from symptom onset to possible reperfusion. Thus, ischemic stroke patients may be particularly sensitive to changes in BP during the endovascular therapy procedure.”
Determination of optimal BP
“Continuous measurement of cerebral vasoreactivity/autoregulation during the endovascular therapy procedure may theoretically allow for determination of optimal BP in a particular patient,” Rasmussen said in an interview. “We are currently looking into whether it is possible to determine optimal BP for a particular patient and adjust the BP according to this optimal target during the procedure. It is also important to consider BP management for the immediate post-reperfusion/post-endovascular therapy procedure period, and currently these targets have not been defined.” – by Scott Buzby
Disclosures: Rasmussen reports he received support from the Health Research Foundation of Central Denmark Region and the National Helicopter Emergency Medical Service Foundation. Please see the study for all other authors’ relevant financial disclosures.