Therapeutic efficacy of candidate antischistosomal drugs in a murine model of schistosomiasis mansoni.

Schistosomiasis is a neglected tropical disease associated with considerable morbidity. Praziquantel (PZQ) is effective against adult schistosomes, yet, it has little effect on juvenile stages, and PZQ resistance is emerging. Adopting the drug repurposing strategy as well as assuming enhancing the efficacy and lessening the doses and side effects, the present study aimed to investigate the in vivo therapeutic efficacy of the widely used antiarrhythmic, amiodarone, and diuretic, spironolactone, and combinations of them compared to PZQ. Mice were infected by Schistosoma mansoni "S. mansoni" cercariae (Egyptian strain), then they were divided into two major groups: Early- [3 weeks post-infection (wpi)] and late- [6 wpi] treated. Each group was subdivided into seven subgroups: positive control, PZQ, amiodarone, spironolactone, PZQ combined with amiodarone, PZQ combined with spironolactone, and amiodarone combined with spironolactone-treated groups. Among the early-treated groups, spironolactone had the best therapeutic impact indicated by a 69.4% reduction of total worm burden (TWB), 38.6% and 48.4% reduction of liver and intestine egg load, and a significant reduction of liver granuloma number by 49%. Whereas, among the late-treated groups, amiodarone combined with PZQ was superior to PZQ alone evidenced by 96.1% reduction of TWB with the total disappearance of female and copula in the liver and intestine, 53.1% and 84.9% reduction of liver and intestine egg load, and a significant reduction of liver granuloma number by 67.6%. Comparatively, spironolactone was superior to PZQ and amiodarone in the early treatment phase targeting immature stages, while amiodarone had a more potent effect when combined with PZQ in the late treatment phase targeting mature schistosomes.

Combination of spironolactone and DPP-4 inhibitors for treatment of SARS-CoV-2 infection: a literature review.

Coronavirus disease 2019 (COVID-19) is still causing hospitalization and death, and vaccination appears to become less effective with each emerging variant. Spike, non-spike, and other possible unrecognized mutations have reduced the efficacy of recommended therapeutic approaches, including monoclonal antibodies, plasma transfusion, and antivirals. SARS-CoV-2 binds to angiotensin-converting enzyme 2 (ACE2) and probably dipeptidyl peptidase 4 (DPP-4) to initiate the process of endocytosis by employing host proteases such as transmembrane serine protease-2 (TMPRSS-2) and ADAM metallopeptidase domain 17 (ADAM17). Spironolactone reduces the amount of soluble ACE2 and antagonizes TMPRSS-2 and ADAM17. DPP-4 inhibitors play immunomodulatory roles and may block viral entry. The efficacy of treatment with a combination of spironolactone and DPP-4 inhibitors does not appear to be affected by viral mutations. Therefore, the combination of spironolactone and DPP-4 inhibitors might improve the clinical outcome for COVID-19 patients by decreasing the efficiency of SARS-CoV-2 entry into cells and providing better anti-inflammatory, antiproliferative, and antifibrotic effects than those achieved using current therapeutic approaches such as antivirals and monoclonal antibodies.

Beta blockers are associated with lower all-cause mortality among HFpEF patients.

BACKGROUND: The evidence regarding beta blocker (BB) benefit in heart failure with preserved ejection fraction (HFpEF) remains inconclusive, leading to consideration of BB withdrawal in this population. OBJECTIVES: In this study, we retrospectively analyzed the association of BB on all-cause mortality in HFpEF patients. METHODS: This is a single-center retrospective cohort study of 20,206 patients with left ventricular ejection fraction (EF) ≥ 50% who were hospitalized with decompensated HF between January 2011 and March 2020. Survival is reported at 30 days, 1 year, and 3 years. A secondary analysis comparing mortality for patients on BB with additional indications including hypertension (HTN), coronary artery disease (CAD), and atrial fibrillation (AF) was completed. Mortality was compared between patients on BB and additional therapies of spironolactone or angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARBs). RESULTS: BB showed lower all-cause mortality at 30 days, 1 year, and 3 years (p < 0.0001). This association with lower all-cause mortality was validated by a supplementary propensity score-matched analysis. At 3 years, there was significant mortality reduction with addition of BB to either spironolactone (p = 0.0359) or ACEi/ARBs (p < 0.0001). CONCLUSION: In a large single-center retrospective registry, BB use was associated with lower mortality in HFpEF patients with a recent decompensated HF hospitalization. The mortality benefit persisted in those treated with spironolactone or ACEi/ARBs, and in those with AF. This provocative data further highlights the uncertainty of the benefit of BB use in this cohort and calls for re-consideration of BB withdrawal, especially in those tolerating it well, without conclusive, large, and randomized trials showing lack of benefit or harm.

Eplerenone reduces lymphangiogenesis in the contralateral kidneys of UUO rats.

Inflammation and fibrosis often occur in the kidney after acute injury, resulting in chronic kidney disease and consequent renal failure. Recent studies have indicated that lymphangiogenesis can drive renal inflammation and fibrosis in injured kidneys. However, whether and how this pathogenesis affects the contralateral kidney remain largely unknown. In our study, we uncovered a mechanism by which the contralateral kidney responded to injury. We found that the activation of mineralocorticoid receptors and the increase in vascular endothelial growth factor C in the contralateral kidney after unilateral ureteral obstruction could promote lymphangiogenesis. Furthermore, mineralocorticoid receptor activation in lymphatic endothelial cells resulted in the secretion of myofibroblast markers, thereby contributing to renal fibrosis. We observed that this process could be attenuated by administering the mineralocorticoid receptor blocker eplerenone, which, prevented the development of fibrotic injury in the contralateral kidneys of rats with unilateral ureteral obstruction. These findings offer valuable insights into the intricate mechanisms underlying kidney injury and may have implications for the development of therapeutic strategies to mitigate renal fibrosis in the context of kidney disease.

Blood Pressure Lowering in Patients With Central Hypertension: A Randomized Clinical Trial.

BACKGROUND: Cuff blood pressure (BP) is recommended for guiding hypertension management. However, central BP has been proposed as a superior clinical measurement. This study aimed to determine whether controlling hypertension as measured by central BP was beneficial in reducing left ventricular mass index beyond control of standard cuff hypertension. METHODS: This multicenter, open-label, blinded-end point trial was conducted in individuals treated for uncomplicated hypertension with controlled cuff BP (<140/90 mm Hg) but elevated central BP (≥0.5 SD above age- and sex-specific normal values). Participants were randomized to 24-months intervention with spironolactone 25 mg/day (n=148) or usual care control (n=153). The primary outcome was change in left ventricular mass index measured by cardiac MRI. Cuff and central BPs were measured by clinic, 7-day home and 24-hour ambulatory BPs. RESULTS: At 24-months, there was a greater reduction in left ventricular mass index (-3.2 [95% CI, -5.0 to -1.3] g/m2; P=0.001) with intervention compared with control. Cuff and central BPs were lowered by a similar magnitude across all BP measurement modes (eg, clinic cuff systolic BP, -6.16 [-9.60 to -2.72] mm Hg and clinic central systolic BP, -4.96 [-8.06 to -1.86] mm Hg; P≥0.48 all). Secondary analyses found that changes in left ventricular mass index correlated to changes in BP, with the magnitude of effect nearly identical for BP measured by cuff (eg, 24-hour systolic BP, ß, 0.17 [0.02-0.31] g/m2) or centrally (24-hour systolic BP, ß, 0.16 [0.01-0.32] g/m2). CONCLUSIONS: Among individuals with central hypertension, spironolactone had beneficial effects in reducing LV mass. Secondary analyses showed that changes in LV mass were equally well associated with lower measured standard cuff BP and central BP. REGISTRATION: URL: https://www.anzctr.org.au/; Unique identifier: ACTRN12613000053729.

Chronic unpredictable mild stress increases serum aldosterone without affecting corticosterone levels and induces hepatic steatosis and renal injury in young adult male rats.

Stress is often associated with anxiety and depressive symptoms in adolescents. Stress is associated with components of metabolic syndrome and inflammation. The present study hypothesizes that aldosterone, more than corticosterone, promotes chronic stress-hepatic steatosis and fibrosis, as well as renal inflammation and fibrosis in young adult rats. Thirty-two young adult male Wistar rats of 51 days old were divided into four groups (n = 8 per group): Control (C), chronic unpredictable mild stress (CUMS), control plus vehicle (C plus veh), CUMS plus eplerenone, a selective aldosterone blocker (CUMS plus EP). On postnatal day 51, eplerenone was administered orally through a gastric tube two hours before the start of the stress test. The CUMS paradigm was administered once daily at different times, with no repetition of the stressor sequence for four weeks. Renal inflammation and fibrosis were measured, as well as liver glycogen, triacylglycerol, and fibrosis levels. The serum concentrations of corticosterone, aldosterone, sodium, and creatinine were measured in urine and serum. The CUMS group showed a high level of serum aldosterone without affecting the level of corticosterone, increased urinary sodium, tubular atrophy, glomerular sclerosis, the presence of inflammation, and fibrosis, without affecting creatinine, increased glycogen content, triacylglycerol, and moderate fibrosis in the liver, and treatment with eplerenone prevented the inflammation, fibrosis, glycogen, and triacylglycerol. Our results show that chronic stress-induced aldosterone promotes hepatic steatosis and renal injury more than corticosterone. The prevention by eplerenone supports our hypothesis.

Testosterone Deficiency in Hypertensive Men: Prevalence and Associated Factors. / Deficiência de Testosterona em Homens Hipertensos: Prevalência e Fatores Associados.

BACKGROUND: Testosterone deficiency (TD) is a prevalent condition in our midst and still very neglected. Arterial hypertension (AH) is one of the possible associated factors. OBJECTIVES: To determine the prevalence of TD in a hypertensive male population and the factors associated with its occurrence, such as age, time since hypertension diagnosis, number of antihypertensive classes, body mass index (BMI), diabetes, dyslipidemia, chronic kidney disease (CKD), positive symptoms of TD (positive ADAM questionnaire) and use of spironolactone. METHODS: Cross-sectional study with administration of the ADAM questionnaire, assessment of biochemical, clinical, and anthropometric data. Patients were stratified into DT and normal testosterone groups. Categorical variables were compared using the chi-squared test and continuous variables using the Mann-Witney test; variables with significance (p<0,05) were analyzed by multivariable linear regression. RESULTS: The prevalence of TD was 26.36%. There was an association between TD and body mass index (BMI) (p=0.0007) but there was no association with age (p=0.0520), time of hypertension diagnosis (p=0.1418), number of classes of antihypertensive drugs (p=0.732), diabetes (p=0.1112); dyslipidemia (p=0.3888); CKD (p=0.3321); use of spironolactone (p=0.3546) or positive ADAM questionnaire (p=0.2483). CONCLUSIONS: TD was highly prevalent and positively associated with BMI. Total testosterone (TT) declined by 8.44ng/dL with a one unit increase in BMI and dropped by 3.79ng/dL with a one-year increase in age.

FUNDAMENTO: A deficiência de testosterona (DT) é uma condição prevalente em nosso meio e ainda muito negligenciada. A hipertensão arterial (HA) é um de seus possíveis fatores associados. OBJETIVOS: Determinar a prevalência de DT em uma população masculina hipertensa e os fatores associados à sua ocorrência, como idade, tempo de diagnóstico de HA, número de classes de anti-hipertensivos, índice de massa corporal (IMC), diabetes, dislipidemia, doença renal crônica (DRC), sintomas positivos de DT (questionário ADAM positivo) e uso de espironolactona. MÉTODOS: Estudo transversal com aplicação do questionário ADAM, e avaliação de dados bioquímicos, clínicos e antropométricos. Os pacientes foram estratificados em grupos de DT e testosterona normal. As variáveis categóricas foram comparadas pelo teste do qui-quadrado e as variáveis contínuas pelo teste de Mann-Witney; as variáveis com significância (p<0,05) foram submetidas à regressão linear multivariada. RESULTADOS: A prevalência de DT foi de 26,8%. Houve associação entre DT e IMC (p=0,0007), mas não houve com idade (p=0,0520), tempo de diagnóstico de HA (p=0,1418), número de classes de anti-hipertensivos (p=0,0732), diabetes (p=0,1112); dislipidemia (p=0,3888); presença de DRC (p=0,3321); uso de espironolactona (p=0,3546) e questionário ADAM positivo (p=0,2483). CONCLUSÕES: A prevalência de DT foi alta e houve associação positiva com IMC. A testosterona total (TT) declinou 8,44 ng/dL com o aumento de 1 kg/m2 no IMC e caiu 3,79 ng/dL com o avanço em um ano na idade.

Effect of spironolactone on survival in patients undergoing maintenance hemodialysis.

BACKGROUND: Previous studies have reported inconsistent results regarding the advantages or disadvantages of spironolactone use in patients undergoing hemodialysis (HD). This study aimed to evaluate survival according to the use of spironolactone in a large sample of patients undergoing maintenance HD. METHODS: This retrospective study used laboratory and clinical data from the national HD Quality Assessment Program and claims data. The participants of the quality assessment program were patients who had been undergoing maintenance HD for ≥ 3 months, patients undergoing HD at least twice a week. Patients with no spironolactone prescription during the assessment periods were designated as the control group. Patients with one or more prescriptions of spironolactone during the assessment periods were assigned to the SPR group. RESULTS: The number of patients in the control and SPR groups were 54,588 and 315, respectively. The 5-year survival rates were 69.1% and 59.1% in the control and SPR groups, respectively (P < 0.001). Cox regression analyses showed that the hazard ratio in the SPR group was 1.34 (P < 0.001) in univariate analysis and 1.13 (P = 0.249) in multivariable analysis. Univariate Cox-regression analysis showed a better patient survival rate in the control group than in the SPR group; however, multivariable analyses showed similar patient survival rates between the two groups. CONCLUSION: This study showed no difference in survival between patients undergoing HD with and without spironolactone use.

Sildenafil as a Candidate Drug for Alzheimer's Disease: Real-World Patient Data Observation and Mechanistic Observations from Patient-Induced Pluripotent Stem Cell-Derived Neurons.

Background: Alzheimer's disease (AD) is a chronic neurodegenerative disease needing effective therapeutics urgently. Sildenafil, one of the approved phosphodiesterase-5 inhibitors, has been implicated as having potential effect in AD. Objective: To investigate the potential therapeutic benefit of sildenafil on AD. Methods: We performed real-world patient data analysis using the MarketScan® Medicare Supplemental and the Clinformatics® databases. We conducted propensity score-stratified analyses after adjusting confounding factors (i.e., sex, age, race, and comorbidities). We used both familial and sporadic AD patient induced pluripotent stem cells (iPSC) derived neurons to evaluate the sildenafil's mechanism-of-action. Results: We showed that sildenafil usage is associated with reduced likelihood of AD across four new drug compactor cohorts, including bumetanide, furosemide, spironolactone, and nifedipine. For instance, sildenafil usage is associated with a 54% reduced incidence of AD in MarketScan® (hazard ratio [HR] = 0.46, 95% CI 0.32- 0.66) and a 30% reduced prevalence of AD in Clinformatics® (HR = 0.70, 95% CI 0.49- 1.00) compared to spironolactone. We found that sildenafil treatment reduced tau hyperphosphorylation (pTau181 and pTau205) in a dose-dependent manner in both familial and sporadic AD patient iPSC-derived neurons. RNA-sequencing data analysis of sildenafil-treated AD patient iPSC-derived neurons reveals that sildenafil specifically target AD related genes and pathobiological pathways, mechanistically supporting the beneficial effect of sildenafil in AD. Conclusions: These real-world patient data validation and mechanistic observations from patient iPSC-derived neurons further suggested that sildenafil is a potential repurposable drug for AD. Yet, randomized clinical trials are warranted to validate the causal treatment effects of sildenafil in AD.

Spironolactone metabolite causes falsely increased progesterone in the Abbott Architect immunoassay.

BACKGROUND: Immunoassays are important for routine clinical testing and medical diagnosis. However, they are limited by cross-reactivity especially at low analyte concentrations. There is a critical need to investigate compounds that can interfere with immunoassays. Herein, we describe the identification of canrenone, a spironolactone metabolite that falsely increases progesterone concentrations on the Abbott Architect i2000 Immunoassay. METHODS: Serum samples and assay diluents were spiked with spironolactone or canrenone and progesterone concentrations were measured on the Architect i2000 and Immulite XPi immunoassay platforms. Blood samples from patients taking spironolactone were analyzed with liquid chromatography-tandem mass spectrometry to evaluate the intrinsic response of progesterone concentrations to the presence of canrenone. RESULTS: We measured approximately 10-fold higher progesterone concentrations on the Abbott Architect i2000 compared to reference immunoassay analyzers (Siemens Immulite XPi and Roche Cobas e601/602), suggesting an analytical error which is unique to the Architect i2000 antibody and/or assay conditions. By measuring serum progesterone after addition of spironolactone or canrenone to serum samples, we found that canrenone falsely increased progesterone on the Architect i2000 immunoassay. However, this interference was more pronounced at low serum progesterone concentrations. Moreover, a strong positive correlation was seen between canrenone and measured serum progesterone concentrations. CONCLUSIONS: Our investigations are important for individuals who require progesterone measurements using the Architect i2000 immunoassay, especially because it is unlikely for clinicians to order canrenone measurements alongside progesterone measurements for individuals taking spironolactone. Further research is needed to determine whether canrenone can influence progesterone measurements on other immunoassay systems.

Therapeutic potential of ramipril, losartan, and spironolactone against sepsis-associated liver tissue injury induced by cecal ligation and puncture in rats.

OBJECTIVE: Sepsis-associated liver injury is responsible for the high morbidity and mortality rates seen with septic shock. Activation of the renin-angiotensin-aldosterone system (RAAS) is an essential counteractive mechanism during the hypotensive phase of sepsis; however, excessive activation is associated with exaggerated pro-oxidant and inflammatory response, which aggravates organ damage. This study aimed to evaluate the effect of RAAS inhibition on sepsis-induced liver damage. MATERIALS AND METHODS: The cecal ligation and puncture (CLP) model was employed as a model of sepsis. Rats were divided into five groups: sham-operated, vehicle-treated septic rats, septic rats treated with ramipril in a dose of 10 mg/kg, septic rats treated with losartan in a dose of 20 mg/kg, and finally septic rats treated with spironolactone in a dose of 25 mg/kg. Rats received the treatment one hour after induction. Twenty-four hours later, rats were euthanized, and serum samples and liver tissue were collected to evaluate liver function and hepatic oxidative, anti-oxidative, inflammatory, and apoptotic markers. The microscopic integrity of the hepatic tissue was also assessed. RESULTS: The results of our study showed that all the treatments used ameliorated sepsis-induced liver injury. This was reflected by improved liver function parameters and histopathological appearance of liver tissue. Treatment with ramipril, losartan, or spironolactone reduced tissue malondialdehyde (MDA), nitric oxide, activated caspase-3, and TNF-α. Moreover, these drugs increased hepatic reduced-glutathione (GSH) levels, superoxide dismutase (SOD) activity, and proliferating cell nuclear antigen (PCNA) expression. CONCLUSIONS: Administration of ramipril, losartan, or spironolactone after CLP produced a hepatoprotective effect in rats, possibly by reducing oxidative stress, inflammation, and apoptosis.

Subthreshold laser compared to oral spironolactone for the treatment of chronic central serous chorioretinopathy: a retrospective study.

PURPOSE: To compare functional and morphological outcomes of Subthreshold Laser (STL) and Oral Spironolactone (SPR) in treating chronic central serous chorioretinopathy (CSCR). METHODS: This is a retrospective observational study. Treatment-naïve patients with chronic CSCR treated with STL or SPR were included, and data was reviewed at baseline, 1, 3, 6 and 12-month follow-up. Main outcome measures were changes in Central Macular Thickness (CMT) and Subretinal Fluid (SRF) height, and complete resolutions of SRF. Sub-analysis based on retinal pigmented epithelium (RPE) status at baseline was performed. RESULTS: 47 and 47 patients received STL and SPR, respectively. At all timepoints, both treatments significantly improved CMT and SRF (p < 0.05). No significant changes in best corrected visual acuity (BCVA) were recorded and no significant differences between treatment groups were present at each corresponding follow-up. Complete resolution of SRF was achieved in 29% and 36% of patients treated with STL or SPR, respectively, at 12-months follow up. Eyes treated with STL and intact RPE showed significant SRF decrease at 6 months and significantly better BCVA at 1, 3 and 6 months compared to eyes with disrupted RPE layer (p < 0.05). In both treatment groups, intact RPE was associated with a higher rate of complete SRF resolutions, with 43% vs 13% in the STL group and 50% vs 26% in the SPR group. CONCLUSION: STL and SPR are effective treatments for chronic CSCR. Greater resolution of subretinal fluid was observed in eyes with intact RPE, hence both treatments should be initiated in the earlier stages of the disease.

Association of spironolactone use with risk of urinary tract cancer in the general population: A matched population-based cohort study.

PURPOSE: The correlation between spironolactone usage and cancer risk has sparked interest. The objective of this study is to examine the association between spironolactone use and the incidence of urinary tract cancer in the general population. METHODS: We conducted a matched population-based cohort study. The study population was obtained from the Taiwan National Health Insurance Research Database (TNHIRD) during the period from 2000 to 2016. The multivariate Cox proportional hazard model was performed to examine the impact of spironolactone use on the risk of urinary tract cancer. A total of 8,608 individuals exposed to spironolactone were exact matched by 1:1 ratio with unexposed controls on factors including age, gender, comorbidities, CCI scores and socioeconomic status. The incidences of urinary tract cancer, including prostate, renal and bladder cancer, were estimated in both spironolactone exposed and non-exposed cohorts. RESULTS: After adjusting for confounding variables, the multivariate Cox regression analysis showed no significant association between spironolactone exposure and urinary tract cancer incidence, including bladder (adjusted hazard ratio [aHR] = 1.19, 95% confidence interval [CI] = 0.72-1.96, p = 0.50), renal (aHR = 1.75, 95% CI = 0.99-3.07, p = 0.053), and prostate cancer (aHR = 0.67, 95% CI = 0.43-1.04, p = 0.07). When the population was stratified into low (cumulative dose < = 29,300 mg) and high (cumulative dose >29,300 mg) dose of spironolactone, only high dose of spironolactone use was significantly associated with a reduced risk of prostate cancer (aHR = 0.45, 95% CI = 0.23-0.89, p = 0.02), while being associated with an elevated risk of renal cancer (aHR = 2.09, 95% CI = 1.07-4.08, p = 0.03). However, no clear cumulative dose-response relationship was observed in theses associations. CONCLUSIONS: High cumulative dose of spironolactone may be potentially associated with a decreased incidence of prostate cancer and an increased incidence of renal cancer, while no significant association was observed with bladder cancer incidence. However, given the lack of support from the dose-response pattern, the available evidence is inconclusive to establish a definitive association between spironolactone use and urinary tract cancer.

Bidirectional pharmacokinetics of doravirine, tenofovir, and feminizing hormones in transgender women (IDentify): A randomized crossover trial.

Transgender women may have concerns of drug interactions between feminizing hormone therapy (FHT) and antiretrovirals, leading to nonadherence. This randomized, three-period crossover, open-label, phase I trial assessed the effects of doravirine (DOR) and tenofovir disoproxil fumarate (TDF) on the pharmacokinetics (PKs) of estradiol, spironolactone, and total testosterone and vice versa in healthy transgender women. Volunteers were randomized 1:1 into two sequences containing three treatment groups (DOR, lamivudine [3TC], and TDF alone; estradiol, spironolactone, and placebo; and DOR/3TC/TDF, estradiol, and spironolactone). Eight subjects enrolled in the study and six had completed all study periods. The geometric mean ratios for DOR area under the concentration-time curve from zero to last measured concentration (AUC0-last ), maximum concentration (Cmax ), and concentration at 24 h (C24 ) were similar. However, tenofovir (TFV) AUC0-last , Cmax , and C24 moderately increased by 14%-38%. Last, estradiol AUC0-last , Cmax , and C24 were increased by 10%-13%. Whereas most 90% confidence intervals did not meet the bioequivalence bounds of 80%-125%, the point estimates fell within the intervals. Log-transformed DOR, TFV, and estradiol PK parameters computed with and without co-administration were not statistically different (p > 0.05). There were no serious adverse events. There is not a clinically significant impact of FHT on DOR/TFV PKs. Similarly, there is no observed impact on estradiol PKs and total testosterone following use of DOR/3TC/TDF.

Effectiveness and safety of early treatment with spironolactone for new-onset acute heart failure.

BACKGROUND: The effectiveness and safety of mineralocorticoid receptor antagonists (MRA) in acute heart failure (HF) is uncertain. We sought to describe the prescription of spironolactone during acute HF and whether early treatment is effective and safe in a real-world setting. METHODS: We performed a retrospective cohort study of adult (≥18 years) nonpregnant patients hospitalized with new-onset HF with reduced ejection fraction (HFrEF, defined by ejection fraction ≤40%) within 15 Kaiser Permanente Southern California medical centers between 2016 and 2021. Early treatment was defined by spironolactone prescription at discharge. The primary effectiveness outcome was a composite of HF readmission or all-cause mortality at 180 days. Safety outcomes were hypotension and hyperkalemia at 90 days. RESULTS: Among 2318 HFrEF patients, 368 (15.9%) were treated with spironolactone at discharge. After 1:2 propensity score matching, 354 early treatment and 708 delayed/no treatment patients were included in the analysis. The median age was 63 (IQR: 52-74) years; 61.6% were male, and 38.6% were White. By 90 days, ~20% had crossed over in the two groups. Early treatment was not associated with the composite outcome at 180 days (HR [95% CI]: 0.81 [0.56-1.17]), but a trend towards benefit by 365 days that did not reach statistical significance (0.78 [0.58-1.06]). Early treatment was also associated with hyperkalemia (subdistribution HR [95% CI]: 2.33 [1.30-4.18]) but not hypotension (0.93 [0.51-1.72]). CONCLUSIONS: Early treatment with spironolactone at discharge for new-onset HFrEF in a real-world setting did not reduce the risk of HF readmission or mortality in the first year after discharge. The risk of hyperkalemia was increased.