In the Randomized Spironolactone Evaluation Study (RALES), spironolactone was shown to reduce morbidity and mortality in patients with severe heart failure. Patients enrolled in this trial were those with New York Heart Association (NYHA) Class III and IV heart failure, normal serum potassium levels, and normal or only slightly elevated serum creatinine levels. The dosage used in this study was substantially less than the dosage normally used in the treatment of cirrhosis or hypertension (25 to 50 mg per day). Spironolactone is easier to start and titrate than the standard heart failure treatment of angiotensin-converting enzyme (ACE) inhibitors and beta blockers. Because long-term outcome data are not available, Bozkurt and associates studied the appropriateness and complications of the use of spironolactone in the treatment of heart failure in clinical practices.
Patients who received prescriptions for spironolactone during a five-month period were eligible for the study. The medical records of those who met the inclusion criteria were reviewed for 12 months after spironolactone was initiated. Primary objectives were to determine if the patients met the criteria for using spironolactone in advanced heart failure, if the management followed the RALES trial criteria, and the incidence of complications following spironolactone use. Secondary objectives were to determine adverse events related to hyperkalemia, incidence of hypotension, and correlation between the management index and the specialization and training of physicians.
Of the patients who were started on spironolactone, only about 26 percent had documented NYHA class III and IV heart failure and met the RALES criteria. Sixty-five percent of the study group had no documentation of their NYHA class. Most patients were receiving ACE inhibitor or angiotensinreceptor blocker therapy. The mean daily dosages of ACE inhibitors and spironolactone in the study population were higher than in the RALES trial. Less than 40 percent of the study population had appropriate laboratory and clinical follow-up. Twenty-four percent of the patients developed hyperkalemia, with 12 percent developing severe hyperkalemia. Three percent of the patients required temporary pacemaker insertion.
The authors conclude that spironolactone is being used to treat heart failure without consideration of the NYHA class or other appropriate criteria for initiating therapy. They add that clinical follow-up did not adhere to the RALES trial guidelines, resulting in a higher incidence of complications. The goal of therapy should be to maximize the use of ACE inhibitors and beta blockers in the treatment of heart failure.