A decades-old, inexpensive blood pressure medication helped more than half of stroke survivors hit a critical health target that eluded most people on standard care alone, according to new trial results presented at the American Heart Association’s Scientific Sessions, held Nov. 6-9, 2026, in Chicago.
The study, called the REDUCE trial, tested whether adding spironolactone, a water pill, to standard post-stroke treatment could push blood pressure down further than usual care. Researchers split 160 participants into two groups: one added spironolactone, the other stuck with their existing regimen.
The results were stark. After three months, patients on spironolactone had a top blood pressure number averaging around 126, compared to about 133 for those on usual care — a nearly eight-point gap. More importantly, 52% of the spironolactone group reached the recommended target of under 130/80, versus just 30% on usual care alone.
“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 Dr. Jordana Cohen, study co-lead author and associate professor of medicine and epidemiology 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 drug itself is nothing new — spironolactone has long been used as a diuretic, helping the body shed excess salt and water, which lowers blood pressure. But it also causes the body to retain potassium, meaning patients on it need regular blood monitoring.
Dr. Alfred Joshua, a California-based board-certified emergency physician not involved in the study, called the findings encouraging but cautioned they stop short of proving the drug prevents another stroke outright.
“We already know that controlling blood pressure lowers the risk of another stroke. This study measured blood pressure, so whether adding spironolactone leads to fewer repeat strokes is still an open question.”
Joshua flagged high potassium as the chief safety concern, warning it can build up silently, with greater risk for people who have kidney problems or take potassium supplements or certain other medications. The drug can also drop blood pressure enough to cause dizziness.
“If your blood pressure is still high after a stroke, bring your home readings to your clinician and ask whether this medication is a good fit,” Joshua said.
The trial has real limits. It was designed to enroll 200 participants but ended early at 160, and about 15% of participants lacked blood pressure readings at the three-month mark. Patients on spironolactone were also taking slightly more blood pressure medications overall than those on usual care. Researchers say larger, longer trials are still needed to establish whether the drug actually cuts the rate of repeat strokes or heart attacks — this study measured blood pressure numbers, not outcomes.
