Lack of evidence of lower 30-day all-cause readmission in Medicare beneficiaries with heart failure and reduced ejection fraction discharged on spironolactone

Abstract

Background: Therapy with evidence-based heart failure (HF) medications has been shown to be associated with lower risk of 30-day all-cause readmission in patients with HF and reduced ejection fraction (HFrEF).

Methods: We examined the association of aldosterone antagonist use with 30-day all-cause readmission in this population. Of the 2443 Medicare beneficiaries with HF and left ventricular EF ≤35% discharged home from 106 Alabama hospitals during 1998-2001, 2060 were eligible for spironolactone therapy (serum creatinine ≤2.5 for men and ≤2mg/dl for women, and serum potassium <5mEq/L). After excluding 186 patients already receiving spironolactone on admission, the inception cohort consisted of 1874 patients eligible for a new discharge prescription for spironolactone, of which 329 received one. Using propensity scores for initiation of spironolactone therapy, we assembled a matched cohort of 324 pairs of patients receiving and not receiving spironolactone balanced on 34 baseline characteristics (mean age 72years, 42% women, 33% African American).

Results: Thirty-day all-cause readmission occurred in 17% and 19% of matched patients receiving and not receiving spironolactone, respectively (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.64-1.32; p=0.650). Spironolactone had no association with 30-day all-cause mortality (HR, 0.84; 95% CI, 0.38-1.88; p=0.678) or HF readmission (HR, 0.74; 95% CI, 0.41 1.31; p=0.301). These associations remained unchanged during 12months of post-discharge follow-up.

Conclusion: A discharge prescription for spironolactone had no association with 30-day all-cause readmission among older, hospitalized Medicare beneficiaries with HFrEF eligible for spironolactone therapy.

Keywords: 30-day all-cause readmission; Heart failure; Medicare beneficiaries; Spironolactone.

Fig. 1

Love plot displaying absolute standardized differences for 34 baseline characteristics of hospitalized patients with heart failure and reduced ejection fraction receiving and not receiving spironolactone, before and after propensity score matching (ACE=angiotensin-converting enzyme; ARB=angiotensin receptor blockers)

Fig. 2

Kaplan-Meier plots displaying association between pre-discharge initiation of spironolactone and all-cause readmission in a propensity-matched cohort of hospitalized Medicare beneficiaries with heart failure and reduced ejection fraction (CI=confidence interval)