The Effect of Spironolactone Use on Heart Failure Mortality: A Population-Based Study

BackgroundSpironolactone use for heart failure (HF) has increased dramatically after the publication of the Randomized Aldactone Evaluation Study trial; yet, few studies have examined its real-world impact. We aimed to determine the population effect of spironolactone use on mortality in HF patients discharged from hospital.Methods and ResultsAll patients discharged alive between October 1997 and December 2001 in Nova Scotia, Canada, with a primary diagnosis of HF were enrolled in the Improving Cardiovascular Outcomes Study. Two year, all-cause mortality was the primary end point. A total of 7816 patients were identified, of whom 644 (8%) were discharged home on spironolactone. After adjusting for differences in clinical covariates, spironolactone use did not emerge as an independent predictor of long-term survival (OR 0.97, P = .80). When only the subgroup of patients enrolled in a HF clinic were included (n = 990), spironolactone use was associated with reduced rates of all-cause mortality at 2 years (OR 0.52, P = .003).ConclusionsAlthough spironolactone use was not associated with improved long-term survival in the general HF population, it was associated with improved long-term survival in patients enrolled in HF clinics. These data highlight the challenges of knowledge translation from a clinical trial into practice.