Study of High-dose Spironolactone vs. Placebo Therapy in Acute Heart Failure

Mineralocorticoid receptor antagonist (MRA) therapy is recommended in stable chronic systolic heart failure (HF) and post-infarction HF patients for improving morbidity and mortality. MRA therapy in AHF and in high doses is less well studied. The effectiveness and safety of early high dose MRA therapy in AHF is supported by a single-blind study showing lower risk of worsening renal function and need for loop diuretics, and improved congestion. MRA therapy in AHF may improve outcomes by relieving congestion at higher doses through their natriuretic property, in addition to preventing the deleterious effects of exacerbation of neuro-hormonal activation by loop diuretics. This randomized, double blind, placebo-controlled study of high-dose spironolactone vs. placebo (for patients not receiving MRA at home) or low-dose spironolactone (for patients already receiving low-dose spironolactone) in AHF, will enroll 360 participants at approximately 30 clinical centers. After obtaining informed consent, subjects who fulfill all the inclusion criteria and none of the exclusion criteria will be randomized. Randomization will be performed by using procedures determined by the Coordinating Center (CC). * Patients receiving no MRA therapy at baseline will be randomized to receive either spironolactone 100 mg or placebo daily for 96 hours. * Patients already receiving low-dose spironolactone at baseline (12.5 mg or 25 mg daily) will be randomized to 100 mg or 25 mg spironolactone daily for 96 hours. Within 24 hours prior to randomization, all study participants will undergo: * Medical History * Review of medications including pre-hospital loop diuretics, MRA, and potassium doses * Physical examination, vital signs and body weight * Measurement of creatinine, blood urea nitrogen (BUN), and electrolytes * Dyspnea Relief Assessments (7-point Likert and Visual Analog Scale) * Serum pregnancy test for all women of childbearing potential * Collection of samples for measurement of NT-proBNP levels (Core Lab) Study drug will be initiated as follows: * Patients receiving no MRA therapy at baseline: 4x25 mg study capsules once daily; starting dose 100 mg spironolactone or placebo; if dose adjustment is required, active capsules will be adjusted by pharmacy to achieve the required dose. * Patients already receiving low-dose spironolactone at baseline: 4x25 mg study capsules once daily; one capsule containing 25 mg spironolactone and 3x25 mg study capsules containing spironolactone or placebo; if dose adjustment is required, active capsules will be adjusted by pharmacy to achieve the required dose. Patients will be followed every 24 hours following randomization through 96 hours. Study drug will be administered daily for 96 hours. Study drug administration time is anchored to time of randomization. Dose adjustments (continue, hold, stop) are permitted according to serum K+ and renal function. Assessment at 24 hours post randomization includes: Review of medications, body weight, fluid intake/urine output, creatinine, blood urea nitrogen (BUN), and electrolytes, and adverse events. If the 24 hour assessment is also the day of discharge, include: * Physical exam / Vital signs * Dyspnea Relief (7-Point Likert and VAS) worksheets * Biomarkers (NT-proBNP) (Core Lab) Assessment at 48 hours post randomization includes: Review of medications, physical exam/vital signs, body weight, fluid intake/urine output, Dyspnea Relief (7-Point Likert and VAS) worksheets, creatinine, blood urea nitrogen (BUN), and electrolytes, biomarker levels (NT-proBNP) by Core Lab. Assessment at 72 hours post randomization includes: Review of medications, body weight, fluid intake/urine output, creatinine, blood urea nitrogen (BUN), and electrolytes, and adverse events. If the 72 hour assessment is also the day of discharge, include: * Physical exam / Vital signs * Dyspnea Relief (7-Point Likert and VAS) worksheets * Biomarkers (NT-proBNP) (Core Lab) Assessment at 96 hours post randomization includes: Review of medications, physical exam/vital signs, body weight, fluid intake/urine output, creatinine, blood urea nitrogen (BUN), and electrolytes, Dyspnea Relief (7-Point Likert and VAS), and biomarker levels (NT-proBNP) by Core Lab. If patient is clinically euvolemic in less than 96 hours, the investigator may consider changing loop diuretics to oral dose. Study drug will be discontinued after 96 hours and further use of MRA will be left to the treating physician's discretion. Assessment at Discharge: If discharge occurs after the 96 hour assessment but prior to the 30 day follow-up telephone call,the following will be documented: Medication review (prescribed medications at the time of discharge), body weight (if available), creatinine, blood urea nitrogen (BUN), and electrolytes (if available), and adverse events. Ejection fraction data will be obtained from echocardiogram within 6 months prior to randomization. Those patients who do not have an echocardiogram recorded within this time frame will get an echocardiogram, nuclear perfusion study, MRI, or MUGA performed prior to the 96 hour in-hospital assessment to ascertain ejection fraction. Follow-up Telephone Call at Day 30: All participants will be contacted by telephone at day 30 (+3 days) following randomization to assess tertiary endpoints, including medication use and adverse events. Follow-up Telephone Call at Day 60: All participants will be contacted by telephone at day 60 (+/-3 days) following randomization to assess vital status. During the consent process, patients will be asked if interested in donating samples and data for research purposes via a biorepository and/or genetic study. Based on site and IRB preference, this optional part of the study may be incorporated into the main consent or may be a separate consent and IRB application.