Adoption of spironolactone therapy for older patients with heart failure and left ventricular systolic dysfunction in the United States, 1998-2001

Background - Concerns have been raised about the appropriateness of spironolactone use in some patients with heart failure. We studied the adoption of spironolactone therapy after publication of the Randomized Aldactone Evaluation Study (RALES) in national cohorts of older patients hospitalized for heart failure. Methods and Results - This is a study of serial cross-sectional samples of Medicare beneficiaries >= 65 years old discharged after hospitalization for the primary diagnosis of heart failure and with left ventricular systolic dysfunction. The first sample was discharged before ( April 1998 to March 1999, n = 9758) and the second sample after ( July 2000 to June 2001, n = 9468) publication of RALES in September 1999. We assessed spironolactone prescriptions at hospital discharge in patient groups defined by enrollment criteria for the trial. Using multivariable logistic regression, we identified factors independently associated with prescriptions not meeting these criteria. Spironolactone use increased > 7-fold ( 3.0% to 21.3% P < 0.0001) after RALES. Of patients meeting enrollment criteria, 24.1% received spironolactone, as compared with 17.4% of those not meeting the criteria. Of all prescriptions after RALES, 30.9% were provided to patients not meeting enrollment criteria. Spironolactone was prescribed to 22.8% of patients with a serum potassium value >= 5.0 mmol/L, to 14.1% with a serum creatinine value >= 2.5 mg/dL, and to 17.3% with severe renal dysfunction ( estimated glomerular filtration rate < 30 mL (.) min(-1) (.) 1.73 m(-2)). In multivariable analyses, factors associated with prescriptions not meeting enrollment criteria included advanced age, noncardiovascular comorbidities, discharge to skilled nursing facilities, and care provided by physicians without board certification. Conclusions - Spironolactone prescriptions increased markedly after the publication of RALES, and many treated patients were at risk for hyperkalemia. Simultaneously, many patients who might have benefited were not treated. These findings demonstrate the importance of balancing efforts to enhance use among appropriate patients and minimizing use in patients at risk for adverse events.