MILAN — Two trials yielded different findings regarding the benefits of lowering blood pressure (BP) after an acute intracranial hemorrhage (ICH). When findings from the two trials were combined, there emerged a more positive picture regarding functional outcomes with tighter BP control at 3 months.
For example, researchers reported that in pooled data from 3829 participants, for every 10-mmHg decrease in systolic blood pressure achieved in 24 hours, there was a 10% improvement in Modified Rankin Scale scores.
"We found that achieving sustained, lower levels of systolic blood pressure — as low as 120 to 130 mmHg — was associated with a range of better outcomes after acute ICH," lead author Tom Moullaali, MD, a British Hearth Foundation clinical research training fellow at the University of Edinburgh, United Kingdom, said during a press briefing at the 5th European Stroke Organisation Conference (ESOC) 2019.
"These findings provide support for clinicians when they are managing blood pressure after acute cerebral hemorrhage," he added.
The 2013 Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial 2 (INTERACT2), which involved nearly 3000 participants, showed that reductions in blood pressure to a target of <140 mmHg had a benefit on functional outcomes at 90 days and improved health-related quality of life, as previously reported by Medscape Medical News.
"Current international guidelines are built around those findings," Moullaali said.
In contrast, results were more equivocal in the Antihypertensive Treatment of Acute Cerebral Hemorrhage-II (ATACH-II) study, a randomized controlled trial conducted in 2016. "The second trial reported neutral results," Moullaali said. "We wanted to understand that better."
With the aim of adding more certainty to post-ICH management, Moullaali and colleagues assessed a combined cohort of 3829 individuals. The mean age of the patients was 63 years, 65% were of Asian ethnicity, and 37% were women.
The primary outcome was improvement in function at 90 days, defined as achieving functional independence — a Modified Rankin Scale score of 0–2.
The 10% benefit in this outcome for every 10-mmHg decrease in systolic blood pressure over 24 hours was statistically significant (adjusted odds ratio [aOR], 0.90; 95% confidence interval [CI], 0.87–0.94; P < .0001). "There was a consistent, significant association between achieved BP and outcome," Moullaali added.
In contrast, too much of a reduction in systolic blood pressure too soon could be problematic, he said. A drop of 60 mmHg or more in the first hour, for example, was associated with unfavorable outcomes. "This is evidence for clinicians to achieve those lower levels carefully and sustain them over 24 hours — that is what we are advocating here," Moullaali told Medscape Medical News.
The investigators also assessed the variability in systolic blood pressure or the standard deviation over hours 1 to 24. They found that lower variability was associated with a greater likelihood of functional independence for every 10-mmHg decrease in systolic blood pressure (aOR, 0.87; 95% CI, 0.79–0.97; P = .0124) .
The analyses were adjusted for ethnicity, time to randomization, NIH Stroke Scale score, medical history, intracranial hemorrhage volume, and intraventricular hemorrhage score.
Strengths of the research include a large number of patients and findings from a range of healthcare settings. "But it's also an association study, so we cannot imply causality," Moullaali said.
Expanded Scope Going Forward
"There are lots of unanswered questions in cerebral research broadly," Moullaali replied when asked about the next steps in his research. "Regarding blood pressure, there is a broader collaboration to pool blood pressure data from a range of ICH trials, and that includes lowering blood pressure in the ambulance, a prehospital trial, and trials that lower blood pressure after 24 hours."
In addition, choice of agent to lower blood pressure and identification of patient characteristics that might modify the effects of lowering blood pressure are areas for future investigation, he added.
"These are interesting data that show an association between reduction in blood pressure and the outcomes for these patients," session co-chair Bart Van der Worp, MD, a neurologist at the University Medical Center in Utrecht, the Netherlands, told Medscape Medical News when asked to comment.
"I think this should be further explored in new clinical studies, especially studies with very early treatments," he added.
Moullaali and Van Der Worp had disclosed no relevant financial relationships.
5th European Stroke Organisation Conference (ESOC) 2019: Presented May 23, 2019.
Medscape Medical News © 2019
Cite this: Sustained Lower BP After Acute ICH Linked to Better Outcomes - Medscape - May 29, 2019.