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

OBJECTIVE

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 β 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 β blockers appropriate spironolactone use and close follow-up by a dedicated HF team can minimize the risk for adverse events and complications.