, new research suggests. Preliminary results of a new study showed that using an antihypertensive drug to target systolic blood pressure to below 160 mm Hg or 140 mm Hg in these patients may not be beneficial, and may even be harmful.
“This line of inquiry is probably not worth pursuing,” said stroke neurologist Eva A. Mistry, MBBS, MSCI, assistant professor of clinical neurology and rehabilitation medicine, University of Cincinnati.
Following current blood pressure guidelines in these patients (so targeting blood pressure under 180/105 mm Hg) “is probably reasonable,” unless the patient’s systolic blood pressure goes above 180, Dr. Mistry said. “Artificially trying to lower it may result in harm, at least in terms of the disability outcome.”
The findings were presented at the 2023 International Stroke Conference presented by the American Stroke Association, a division of the American Heart Association.
Endovascular therapy has become standard of care for patients with large vessel occlusion after studies showed “massive benefit,” yet about 50% of patients remain disabled or die at 90 days, Dr. Mistry said.
“We have been on the quest to understand if there’s something we can do to improve these outcomes.”
One approach could be optimizing medical management. Previous observational studies showed that higher blood pressure values after thrombectomy are associated with worse outcomes.
Taking it forward
“We wanted to take that forward in a randomized inquiry to see first with this trial if [artificially] lowering blood pressure using medications is safe, and preliminarily understand if it could be efficacious in a larger trial,” she said.
This blood pressure–lowering strategy is already practiced in some centers. A nationwide survey conducted by Dr. Mistry and her colleagues showed a wide range of targets, with some institutions aiming it as low as under 120 mm Hg after thrombectomy, which she found “surprising.”
The Blood pressure after Endovascular Stroke Treatment-II (BEST-II) study included 120 ischemic stroke patients at three stroke centers, mean age 70 years and 57% female, who had undergone endovascular treatment. They were randomized to one of three target blood pressure groups: 180 mm Hg or under, less than 160 mm Hg, or under 140 mm Hg.
To lower blood pressure, researchers used intravenous nicardipine, a calcium channel blocker, as a first line. This was started within 1 hour of the endovascular treatment and given for 24 hours if the patient’s systolic blood pressure was above the target of their group.
In the highest target group (≤180 mm Hg), the average systolic blood pressure reached 129 mm Hg. In the middle target group (<160 mm Hg), the average systolic blood pressure was 131 mm Hg, and in the lowest target group (<140 mm Hg), systolic blood pressure was lowered to an average of 123 mm Hg.
Mean infarct volumes
At 36 hours, the mean adjusted infarct volume was slightly lower in the lowest blood pressure target group (32.4), compared with the other groups (46.4 for the 180 mm Hg group and 50.7 for the under-160 mm Hg group).
“Based on a model or a slope that would be associated with serial lowering of blood pressure targets, we found the point estimate of the effect size was slightly in the direction of benefit of lower blood pressure targets in terms of lower infarct volume,” Dr. Mistry said.
But this was not conclusive. While the point estimate was in the direction of benefit, Dr. Mistry stressed that the trial design doesn’t “definitely rule out” the possibility of harm.
Researchers also measured functional status at 90 days with the modified Rankin Scale (mRS). They found that the utility-weighted mRS was slightly lower in the lowest blood pressure target group (0.507), compared with the higher target groups (0.584 and 0.475, respectively, for the 180 mm Hg and under-160 mm Hg groups).
“The effect size was slightly in the direction of harm,” Dr. Mistry said. “To me, that means there might be safety issues associated with the lower blood pressure target.”