Stroke survivors with uncontrolled high blood pressure who added an inexpensive diuretic medication called spironolactone to their treatment had lower blood pressure and reached the recommended blood pressure goal nearly twice as often as peers receiving usual post-stroke care, according to preliminary late-breaking science presented at the American Heart Association’s Scientific Sessions 2026 in Chicago.
The findings, from the REDUCE trial, suggest a simple and affordable way to address a critical gap in secondary stroke prevention. High blood pressure is a leading risk factor for having another stroke that can be controlled, according to the 2021 American Heart Association/American Stroke Association Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack. Nearly 1 in 4 stroke survivors will have another stroke, yet up to 80% of strokes can be prevented.
“Lowering blood pressure is the most important step in preventing another stroke, yet many survivors struggle to reach recommended blood pressure targets after a stroke,” said study co-lead author Jordana B. Cohen, M.D., M.S.C.E., FAHA, an associate professor of medicine and epidemiology at the Perelman School of Medicine at the University of Pennsylvania. “When spironolactone was added to post-stroke care, we saw a meaningful drop in blood pressure that may lower the risk of future strokes and heart attacks.”
The REDUCE trial enrolled 160 adult stroke survivors with uncontrolled high blood pressure at five U.S. medical centers. About half had survived an ischemic stroke (clot-caused), and the other half had an intracerebral hemorrhage (bleeding). Participants were randomly assigned to receive daily spironolactone in addition to usual care or to usual care alone. Their blood pressure was tracked at home.
At three months, those taking spironolactone had an average home systolic blood pressure (top number) nearly 8 mm Hg lower than the standard care group—about 126 mm Hg versus 133 mm Hg. Diastolic blood pressure (bottom number) dropped by about 4 mm Hg more in the spironolactone group. By three months, 52% of people taking the diuretic had reached the recommended goal of less than 130/80 mm Hg, compared with 30% of those receiving standard care. At six months, systolic blood pressure remained about 7 mm Hg lower in the spironolactone group.
The medication was well tolerated. Rates of serious side effects requiring hospitalization were similar between groups (15% with spironolactone versus 16% with standard care). High potassium levels occurred in about 4% of the spironolactone group but caused no life-threatening issues.
Spironolactone is a long-available, FDA-approved diuretic that is typically used as a fourth-line blood pressure medication. It works by blocking aldosterone, a hormone that signals the kidneys to retain salt and water. Because it can raise potassium, patients need regular monitoring. “We were surprised to see that blood pressure dropped twice as much as we expected,” Cohen said. “In an exploratory analysis, the blood pressure drop was larger in people who started this medication within three months after a stroke.”
The researchers hope the findings encourage health care professionals to consider adding spironolactone sooner and highlight the importance of home blood pressure monitoring. The study was funded by a Bugher Center grant from the American Heart Association. The abstract is available in the abstract and the 2026 Online Program Planner. As preliminary research presented at a scientific meeting, the findings are considered preliminary until published in a peer-reviewed journal.
