Raising potassium levels cuts risk of arrhythmia, hospitalization and death in high‑risk heart patients, study finds
Randomized trial of 1,200 patients with implantable defibrillators found higher plasma potassium reduced arrhythmia burden without increasing potassium-related hospitalizations
A randomized international trial reported that deliberately increasing plasma potassium to the mid‑to‑high normal range reduced the risk of dangerous heart rhythms, unplanned hospitalizations for arrhythmia or heart failure, and death among patients at high risk for ventricular arrhythmias.
The trial, presented at a major heart conference in Madrid and published in The New England Journal of Medicine, followed 1,200 patients who already had implantable cardioverter‑defibrillators (ICDs) and were considered at high risk for ventricular arrhythmias. The average age of participants was 62 and 19.8% were women. Participants were randomly assigned to an intervention intended to raise potassium — through oral potassium supplementation, a mineralocorticoid receptor antagonist (MRA), or both, together with dietary guidance and standard care — or to a standard‑care control group.
Investigators measured a composite outcome that included episodes of dangerously fast ventricular rhythms, appropriate ICD therapy (shock or pacing), unplanned hospital stays for arrhythmia or heart failure lasting more than 24 hours, and death from any cause. About 23% of participants in the potassium‑targeted group experienced one of these events, compared with 29.2% in the standard‑care group — a 6.5 percentage‑point absolute difference.
When unplanned hospitalization lasting more than 24 hours and death were evaluated together, those outcomes occurred in 29.5% of the group whose potassium was raised to the high‑normal range, versus 33.2% in the control group. Rates of hospital admission for either hyperkalemia (high potassium) or hypokalemia (low potassium) were similar in both groups.
Lead presenters and authors said the treatment‑induced increase in plasma potassium "significantly reduced the arrhythmia burden without increasing the combined risk of hyper‑ or hypokalemia." The senior author called the intervention an inexpensive and widely available strategy that produced benefits across different cardiovascular disease types and regardless of whether potassium was increased with supplements, medication, or diet.
Researchers recommended considering raising potassium to the mid‑to‑high normal range for patients with cardiovascular disease who are at high risk for ventricular arrhythmia. They said common potassium‑rich foods include bananas, avocados, oranges, other fruits and vegetables, dairy products and protein sources.
The trial adds randomized evidence to prior observational studies linking low plasma potassium with higher risk of dangerous heart rhythm disturbances and suggesting protective effects for potassium levels at the upper end of the normal range. Investigators cautioned that the trial population consisted of patients with existing cardiovascular disease and implanted defibrillators, and the findings therefore directly apply to similar high‑risk groups.
The authors noted that increasing potassium can be achieved by several methods and that the observed benefits did not depend on the specific approach used. The trial’s safety data showing no rise in combined hyper‑ or hypokalemia hospitalizations was highlighted as an important finding, given clinical concerns about raising potassium in patients with cardiovascular disease. Further research may define optimal target levels, patient selection and implementation strategies in routine practice.