Spironolactone Fails to Reduce Cardiac Risk in Dialysis Patients, Major Study Finds
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A landmark international study published August 14 in The Lancet challenges conventional wisdom regarding the use of spironolactone in patients undergoing dialysis. The research, presented at the ERA 2025 congress, demonstrates that the medication does not reduce the risk of cardiac death or hospitalizations for heart failure in individuals with kidney failure receiving dialysis.
The Scope of the Study
The comprehensive trial involved 2,538 participants from 143 dialysis centers across 12 countries. All participants had been receiving dialysis for at least three months, with age criteria set at over 45 years, or over 18 years for those with diabetes. this makes it the largest investigation to date examining spironolactone’s effects on this vulnerable population.
Understanding the rationale
Researchers hypothesized that a low daily dose of 25 mg of spironolactone coudl counteract the harmful effects of aldosterone, a hormone known to contribute to cardiac remodeling, fibrosis, and increased cardiovascular risk. Aldosterone levels are often elevated in patients on dialysis, leading scientists to beleive spironolactone could offer a protective benefit. As Michael Walsh, the study’s principal researcher and principal scientist at the Population Health Research Institute (PHRI), explained, “In people with normal kidney function, spironolactone reduces cardiovascular events. However, people receiving dialysis may not respond likewise to treatments proven effective in the general population. We launched this study to determine the safety and efficacy of spironolactone in people with kidney failure.”
Did You Know? Heart disease is the leading cause of death among individuals on dialysis, accounting for approximately 40% of all deaths in this population.
Unexpected Findings and Safety Concerns
Contrary to expectations, spironolactone did not demonstrate any cardiovascular advantage in the study population. Moreover, the drug was associated with a significantly increased risk of severe hyperkalemia – a perilous elevation of potassium levels in the blood that can lead to irregular heart rhythms and, in extreme cases, death. “Previous studies have suggested that this type of medication could help people undergoing dialysis, but they were small and had short follow-ups, unlike our major production study,” Walsh noted.
trial Details and Early Termination
The trial commenced patient recruitment in 2018 and concluded in December 2024. of the 3,565 patients initially enrolled, 2,538 who tolerated the medication during a seven-week run-in period were randomly assigned to receive either 25 mg of spironolactone daily or a placebo. The trial was halted early for futility after an independent data and safety monitoring committee determined there was minimal chance of demonstrating a statistically significant benefit.
| Outcome | Spironolactone Group (n=258) | placebo Group (n=276) |
|---|---|---|
| Cardiovascular Death or Hospitalization for Heart Failure | 258 | 276 |
| Severe Hyperkalemia | 6.6% | 4.5% |
Analysis revealed potential differences in outcomes between men and women, warranting further investigation:
- Men: 163 (spironolactone) vs 201 (placebo)
- Women: 95 (spironolactone) vs 75 (placebo)
The increased incidence of severe hyperkalemia – 6.6% in the spironolactone group compared to 4.5% in the placebo group – raises significant safety concerns for this already vulnerable patient population. “This can be a serious safety problem in an already vulnerable group,” Walsh added.
Pro Tip: Regular monitoring of potassium levels is crucial for patients with kidney failure, especially those taking medications that can affect potassium balance.
implications for Clinical Practice
The findings challenge current practices and highlight the need for caution when considering spironolactone for patients on dialysis.While spironolactone remains a valuable treatment for certain cardiovascular conditions in individuals with normal kidney function [[1]], its use in the dialysis population does not appear to offer the same benefits and carries potential risks. What other therapeutic strategies could be explored to improve cardiovascular outcomes in dialysis patients? And how can we better personalize treatment approaches based on individual patient characteristics?
The study was funded by the canadian Health Research Institutes, Medical Research Future Fund, Health Research Council, British Heart Foundation, PHRI, St. Joseph’s Healthcare Hamilton, Accelerating Clinical Trials Canada, Cansolve CKD, and Dalhousie Department of Medicine.
The Growing Burden of Kidney Failure
Chronic kidney disease (CKD) is a global health crisis, affecting millions worldwide. As CKD progresses, it can lead to end-stage renal disease (ESRD), requiring dialysis or kidney transplantation for survival. The prevalence of CKD is increasing due to factors such as diabetes, hypertension, and an aging population. Ongoing research is critical to identify effective strategies for preventing and managing CKD and improving the quality of life for those affected.
Frequently Asked Questions About Spironolactone and Dialysis
- what is spironolactone? Spironolactone is a medication primarily used to treat high blood pressure and heart failure by blocking aldosterone.
- Why was this study conducted? Researchers wanted to determine if spironolactone could benefit patients on dialysis, a population where heart disease is a major concern.
- What were the main findings of the study? The study found that spironolactone did not reduce the risk of cardiac death or hospitalization for heart failure in dialysis patients and increased the risk of hyperkalemia.
- Is spironolactone still used for heart failure? Yes, spironolactone remains a valuable treatment for heart failure in patients with normal kidney function.
- What are the risks of hyperkalemia? Hyperkalemia, or high potassium levels, can cause irregular heart rhythms and perhaps lead to death.
This research provides essential clarity and underscores the importance of evidence-based medicine.While the results are not what researchers hoped for, they represent a crucial step forward in the pursuit of effective and safe treatments for individuals with kidney failure.
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