BACKGROUND: The incidence of hyperkalemia related to spironolactone use is low in stable heart failure; however, it has not been studied during decompensation. OBJECTIVE: To evaluate the influence of spironolactone on serum potassium in decompensated heart failure (HF). METHODS: In a cohort study, patients that had been hospitalized due to decompensated HF, with left ventricular ejection fraction (LVEF) < 0.45 and serum potassium between 3.5 and 5.5 mEq/l were selected. The patients were divided according to spironolactone use (Group S) or no use (Group C). The outcome was potassium increase (> 6.0 mEq/l) and the use of calcium polystyrene. A multivariate analysis through logistic regression was carried out and values of p < 0.05 were considered significant. RESULTS: A total of 186 patients (group S: 56; group C: 130) were studied; LVEF of 0.25, aged 55.5 years and 65.2% of them males. The incidence of hyperkalemia was 10.7% in group S and 5.4% in group C (p = 0.862). The multivariate analysis showed that serum urea > 60.5 mg/dl during the hospitalization presents a relative risk of 9.6 (95%CI 8.03 - 11.20; p = 0.005) for the occurrence of hyperkalemia. CONCLUSION: The incidence of hyperkalemia was two-fold higher with spironolactone use, but it was not statistically significant. The increase in urea levels was associated to the hyperkalemia. Randomized studies are necessary to clarify this issue.
Heart failure, congestive; hyperkalemia; spirolactone; kidney
