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.
The findings matter because High blood pressure is a leading risk factor for having another stroke, and nearly 1 in 4 stroke survivors will have another stroke. Lowering blood pressure is the most important step in preventing another stroke, yet many survivors struggle to reach recommended targets. The 2021 American Heart Association/American Stroke Association Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack identifies high blood pressure as a leading controllable risk factor.
In the REDUCE trial, 160 adult stroke survivors with uncontrolled high blood pressure were randomized to receive daily spironolactone or usual post-stroke care. At three months, those taking spironolactone had home-measured systolic blood pressure nearly 8 mm Hg lower on average than the standard care group (about 126 mm Hg vs. 133 mm Hg). Diastolic blood pressure dropped by about 4 mm Hg more. 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.
“We were surprised to see that blood pressure dropped twice as much as we expected. In an exploratory analysis, the blood pressure drop was larger in people who started this medication within three months after a stroke,” said 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. “We hope these findings encourage healthcare professionals to consider adding spironolactone sooner.”
Spironolactone is a long-available, low-cost diuretic that blocks aldosterone, a hormone that signals the kidneys to retain salt and water. It is typically the fourth recommended medication for high blood pressure, added when blood pressure remains high despite three other drugs. The medication was well tolerated; serious side effects requiring hospitalization occurred in 15% of the spironolactone group and 16% of the standard care group. About 4% of those taking spironolactone had high potassium levels, but no life-threatening issues occurred.
The trial enrolled participants at five U.S. medical centers, including people who had survived ischemic stroke (clots) or intracerebral hemorrhage (bleeding). Limitations include that the study compared spironolactone with usual care rather than with adding a different blood pressure medication, and that the spironolactone group was taking slightly more blood pressure medications overall at three months. Enrollment ended early at 160 of the planned 200 participants, and about 15% did not have three-month blood pressure readings. The study was not designed to determine whether spironolactone lowers the risk of another stroke or heart attack.
The results are considered preliminary until published as a full manuscript in a peer-reviewed journal. The abstract is available in the American Heart Association’s 2026 Online Program Planner. The study was funded by a Bugher Center grant from the American Heart Association, whose overall financial information is available here. For more information on preventing recurrent strokes, see Preventing Another Stroke and the 2025 Joint Guideline for the Prevention, Detection, Evaluation and Management of High Blood Pressure in Adults.
