Appropriateness and complications of the use of spironolactone in patients treated in a heart failure clinic

Objectives: The widespread use of spironolactone in patients with congestive heart failure (CHF) has resulted in side effects and complications. We analyzed a cohort of patients treated by a dedicated CHF team, in order to examine the tolerability and safety of spironolactone in clinical practice. Methods: We retrospectively evaluated data on 157 patients who were followed by the Heart Failure clinic of whom 100 patients on maximal treatment (all on beta blockers, 99% on ACE inhibitors) received spironolactone. The complications following spironolactone use were defined as: hyperkalemia with serum K 5.2 mEq/l; creatinine 2.0 mg/dl; hyponatremia with serum Na 135 mEq/l, hypotension and side effects such as gynecomastia and abdominal pain. Results: At 1 year follow-up 6 patients developed hyperkalemia (range 5.3-5.9), 4 of them had K >5.5 mEq/l. Two patients developed hyponatremia. Six patients stopped spironolactone for: 1-gynecomastia, 2-worsening renal failure and hyperkalemia, 2-hyperkalemia (5.9 mEq/l) and 1 for bradycardia. There was an increase in mean creatinine level at 1 year (1.12 +/- 0.35 vs. 1.21 +/- 0.38 mg/dl, p=0.02), however, no significant changes were found in GFR (99.9 +/- 33.5 vs. 65.7 +/- 27.7 ml min(-1) 1.73 m(-2), p=ns) and potassium (4.5 +/- 0.4 vs. 4.6 +/- 0.5 mEq/l, p-ns). We found improvement of GFR by >10% in 19 patients and worsening by >10% in 38 patients. No patient was hospitalized or required urgent treatment for spironolactone-related side effects. Conclusions: In patients with CHF on optimal therapy with ACE inhibitors and beta blockers appropriate spironolactone use and close follow-up by a dedicated HF team can minimize the risk for adverse events and complications. (C) 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.