SPIRIT-HF: Spironolactone’s Benefit Still Uncertain in HF With Preserved, Mildly Reduced EF

Why It Matters

Without clear evidence, clinicians cannot confidently prescribe spironolactone for HFpEF/HFmrEF, leaving a therapeutic gap in a growing patient population.

Key Takeaways

• SPIRIT‑HF enrolled 730 of planned 1,564 patients
• Primary endpoint showed no significant benefit of spironolactone
• High discontinuation rates linked to side effects and COVID‑19
• Ongoing SPIRRIT trial aims to enroll 2,000 HFpEF patients
• Meta‑analysis with TOPCAT suggests possible steroidal MRA benefit

Pulse Analysis

Spironolactone’s role in heart‑failure with preserved or mildly reduced ejection fraction remains ambiguous after the under‑powered SPIRIT‑HF trial. The study’s premature termination, caused by COVID‑19‑related funding cuts and enrollment hurdles, left the primary composite endpoint—cardiovascular death or total heart‑failure hospitalizations—statistically inconclusive. Moreover, the trial highlighted a troubling pattern of early drug discontinuation, with half of the spironolactone group stopping treatment by 21 months, largely due to hyperkalemia, hypotension, and renal complications. These safety concerns, coupled with the modest sample size, diminish the reliability of any observed trend toward benefit.

The broader context underscores why the heart‑failure community is eager for more robust data. Prior investigations, such as TOPCAT, produced mixed results, showing regional benefits in the Americas but overall neutrality. Meanwhile, non‑steroidal mineralocorticoid receptor antagonists like finerenone have demonstrated clear efficacy in HFpEF/HFmrEF cohorts, raising questions about class effects versus molecule‑specific outcomes. The ongoing SPIRRIT trial, targeting 2,000 patients across the United States and Sweden, seeks to fill this evidence gap by delivering adequately powered, real‑world insights into steroidal MRA therapy.

For clinicians and payers, the current uncertainty translates into cautious guideline recommendations—class 2b suggestions to consider MRAs in HFpEF/HFmrEF patients—reflecting a balance between potential benefit and known adverse events. Until SPIRRIT or a comparable large‑scale study confirms a net clinical advantage, treatment decisions will likely hinge on individual tolerance, comorbidity profiles, and the availability of alternative agents such as finerenone. The evolving data landscape emphasizes the need for personalized heart‑failure management strategies that integrate emerging trial results with real‑world safety considerations.