For patients who receive clot-busting drugs after a stroke, intensive blood pressure lowering is safe and it reduces their risk of bleeding in the brain, a new study finds.
Brain bleeds are a major potential side effect of clot-busting drugs. But the use of extreme blood pressure lowering to reduce that risk in patients who take the drugs after ischemic stroke has been controversial. (Ischemic stroke is the result of blocked blood flow to the brain.)
To gauge the safety and effectiveness of intensive blood pressure lowering, researchers looked at more than 2,000 stroke patients treated at 110 hospitals in 15 countries between 2013 and 2018.
The investigators looked specifically at systolic blood pressure — that's the top number in a blood pressure reading. Researchers assessed whether lowering it to less than 140 mm Hg could safely reduce the risk of brain bleeds and post-stroke disability better than the standard target of less than 180 mm Hg over three days.
After the intensive regimen, significantly fewer patients had bleeding in the brain and serious bleeding was also less likely. But both groups had similar levels of disability after 90 days.
In addition, the researchers did not identify any harms linked to intensive blood pressure lowering.
More research is needed to learn why the reduced risk of bleeding in the brain did not lead to improved outcomes for patients, the study authors said.
The findings were presented at an American Stroke Association meeting in Honolulu and published in The Lancet on Feb. 7.
"This study now clearly shows more intensive blood pressure control than is currently recommended has the potential to make [clot-busting] treatment safer, by reducing the risk of serious bleeding in the brain," said lead investigator Craig Anderson, executive director of The George Institute for Global Health, in China.
Co-lead investigator Tom Robinson, head of the Cardiovascular Research Center at the University of Leicester, England, said in an institute news release that the findings point to the need for more research to better understand the underlying mechanisms of early intensive blood pressure lowering, "given that the reduction in brain hemorrhage failed to translate into improvements in overall recovery for patients."
Worldwide, stroke accounts for nearly 5 percent of lives lost due to premature death or disability, and 10 percent of all deaths.