Randomized Aldactone Evaluation Study Research Articles

Mineralocorticoid Receptor Antagonists in Patients With Heart Failure and Impaired Renal Function

BackgroundKidney dysfunction often leads to reluctance to start or continue life-saving heart failure (HF) therapy. ObjectivesThis study sought to examine the efficacy and safety of mineralocorticoid receptor antagonists (MRAs) in patients with HF with reduced ejection fraction experiencing significant kidney dysfunction. MethodsWe pooled individual patient data from the RALES (Randomized Aldactone Evaluation Study) and EMPHASIS-HF (Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure) trials. The association between MRA treatment and outcomes was assessed according to whether the estimated glomerular filtration rate (eGFR) declined to <30 mL/min/1.73 m2 or not. The primary outcome was cardiovascular death or HF hospitalization. ResultsAmong 4,355 patients included, 295 (6.8%) experienced a deterioration of eGFR after randomization to <30 mL/min/1.73 m2. These patients had more impaired baseline cardiac and kidney function (eGFR 47.3 ± 13.4 mL/min/1.73 m2 vs 70.5 ± 21.8 mL/min/1.73 m2) and had a higher risk of the primary outcome than patients without eGFR deterioration (HR: 2.49; 95% CI: 2.01-3.08; P < 0.001). However, the risk reduction in the primary outcome with MRA therapy was similar in those who experienced a decrease in eGFR to <30 mL/min/1.73 m2 (HR: 0.65; 95% CI: 0.43-0.99) compared with those who did not (HR: 0.63; 95% CI: 0.56-0.71) (Pinteraction = 0.87). In patients with a decrease in eGFR to <30 mL/min/1.73 m2, 21 fewer individuals (per 100 person-years) experienced the primary outcome with MRA treatment, vs placebo, compared with an excess of 3 more patients with severe hyperkalemia (>6.0 mmol/L). ConclusionsBecause patients experiencing a decrease in eGFR to <30 mL/min/1.73 m2 are at very high risk, the absolute risk reduction with an MRA in these patients is large and this decline in eGFR should not automatically lead to treatment discontinuation.

Steroidal MRA Across the Spectrum of Renal Function: A Pooled Analysis of RCTs

BackgroundMineralocorticoid receptor antagonists (MRAs) are underused in patients with kidney dysfunction, and their efficacy among patients with chronic kidney disease (CKD) is uncertain. ObjectivesThe goal of this study was to analyze the efficacy and safety of steroidal MRAs across the spectrum of estimated glomerular filtration rates (eGFRs) in randomized controlled trials. The study included patients with heart failure (HF) or myocardial infarction and advanced CKD who participated in the RALES (Randomized Aldactone Evaluation Study), EMPHASIS-HF (Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure), TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist) in the Americas, and EPHESUS (Eplerenone Post-AMI Heart Failure Efficacy and Survival Study) trials. MethodsThis study used individual patient data meta-analysis using Cox models stratified by trial with treatment-by-eGFR interaction terms. eGFR was recalculated by using the Chronic Kidney Disease Epidemiology Collaboration creatinine formula. ResultsA total of 12,700 patients were included, of whom 331 (2.6%) had an eGFR ≤30 mL/min/1.73 m2 (mean eGFR: 26.8 ± 3.2 mL/min/1.73 m2). Patients with advanced CKD had higher annualized event rates for all studied outcomes: placebo event rate for the composite of cardiovascular death or HF hospitalization was ∼3-fold higher in patients with eGFR ≤30 compared with those with eGFR >90 mL/min/1.73 m2: 41.6 vs 14.6 events per 100 person-years. MRAs (vs placebo) reduced the composite of cardiovascular death or HF hospitalization, but the effect was attenuated as eGFR decreased: the corresponding HRs by eGFR categories were: HR for >90 mL/min/1.73 m2: 0.62 (95% CI: 0.49-0.78); HR for 61-90 mL/min/1.73 m2: 0.69 (95% CI: 0.61-0.77); HR for 46-60 mL/min/1.73 m2: 0.84 (95% CI: 0.74-0.95); HR for 31-45 mL/min/1.73 m2: 0.79 (95% CI: 0.68-0.91); and HR for ≤30 mL/min/1.73 m2: 0.96 (95% CI: 0.70-1.32) (treatment-by-eGFR interaction P for trend = 0.033). Investigator-reported hyperkalemia and worsening renal function were more frequent (2- to 3-fold) among MRA users, and hyperkalemia was more frequent as eGFR decreased (treatment-by-eGFR interaction P for trend = 0.002). ConclusionsSteroidal MRAs reduced HF hospitalizations and mortality across a wide range of eGFR. However, declining benefit and worsening safety may limit their use in patients with lower eGFR, particularly those with levels ≤30 mL/min/1.73 m2.

The "FIFTY SHADOWS" of the RALES Trial: Lessons about the Potential Risk of Dietary Potassium Supplementation in Patients with Chronic Kidney Disease.

Hyperkalaemia (HK) is one of the most common electrolyte disorders and a frequent reason for nephrological consultations. High serum potassium (K+) levels are associated with elevated morbidity and mortality, mainly due to life-threatening arrhythmias. In the majority of cases, HK is associated with chronic kidney disease (CKD), or with the use of renin–angiotensin–aldosterone system inhibitors (RAASis) and/or mineral corticoid antagonists (MRAs). These drugs represent the mainstays of treatment in CKD, HF, diabetes, hypertension, and even glomerular diseases, in consideration of their beneficial effect on hard outcomes related to cardiovascular events and CKD progression. However, experiences in relation to the Randomised Aldactone Evaluation Study (RALES) cast a long shadow that extends to the present day, since the increased risk for HK remains a major concern. In this article, we summarise the physiology of K+ homeostasis, and we review the effects of dietary K+ on blood pressure and cardiovascular risk in the general population and in patients with early CKD, who are often not aware of this disease. We conclude with a note of caution regarding the recent publication of the SSaSS trial and the use of salt substitutes, particularly in patients with a limited capacity to increase K+ secretion in response to an exogenous load, particularly in the context of “occult” CKD, HF, and in patients taking RAASis and/or MRAs.

Sex differences in mineralocorticoid receptor antagonist trials: a pooled analysis of three large clinical trials.

Women with heart failure (HF) are under-represented in individual randomized clinical trials (RCTs). Little is known about sex-specific treatment effects in HF medications. We evaluated sex differences in the response to mineralocorticoid receptor antagonists (MRAs) in major HF MRA trials, including a broad spectrum of left ventricular ejection fraction (LVEF). Individual patient data fixed-effect meta-analysis was performed using 6167 patients (31.4% were women) recruited in three placebo-controlled RCTs: Randomized Aldactone Evaluation Study (RALES), Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure (EMPHASIS-HF) and Spironolactone for Heart Failure with Preserved Ejection Fraction (TOPCAT)-Americas. Compared to men, women were older, had higher body mass index and lower glomerular filtration rate. They also had higher LVEF and poorer New York Heart Association functional class and were less likely to be taking angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers. Placebo-arm event rates were lower for women compared with men (15.4 vs. 22.1 per 100 person-year; P=0.002). MRAs reduced consistently, in men and women, the relative risk for cardiovascular death or HF hospitalization (P for interaction=0.83), cardiovascular death (P for interaction=0.44) and all-cause death (P for interaction=0.19). These findings remained consistent after adjustment for potential confounders, regardless of LVEF. There was no sex-specific impact of MRA on the rate of hyperkalaemia and worsening renal function during the median 22 months of follow-up. In three large MRA RCTs, women were substantially different from men with regard to their clinical features and event rates. Nonetheless, this meta-analysis supports a consistent and beneficial MRA effect regardless of sex.

Mineralocorticoid Receptor Antagonists, Blood Pressure, and Outcomes in Heart Failure With Reduced Ejection Fraction

ObjectivesThe purpose of this study was to investigate the effects of mineralocorticoid receptor antagonists (MRAs) on systolic blood pressure (SBP) and outcomes according to baseline SBP in patients with heart failure with reduced ejection fraction (HFrEF). BackgroundMRAs are greatly underused in patients with HFrEF, often because of fear of adverse events. Concern about hypotension has been raised by the demonstration that MRAs are particularly effective treatment for resistant hypertension. MethodsThe effect of MRA therapy was studied in 4,396 patients with HFrEF randomized in the RALES (Randomized Aldactone Evaluation Study) and EMPHASIS-HF (Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure) trials. ResultsMean SBP change from baseline to 6 months was +1.4 ± 18.1 mm Hg in the placebo group and −1.2 ± 17.9 mm Hg in the MRA group. The between-treatment difference was 2.6 mm Hg (95% confidence interval [CI]: 1.5 to 3.6; p < 0.001). All outcomes were reduced by MRA therapy overall, with consistent effects across SBP categories (e.g., all-cause mortality, overall hazard ratio [HR] of 0.72; 95% CI: 0.64 to 0.82; p < 0.001; SBP ≤105 mm Hg; HR: 0.72; 95% CI: 0.56 to 0.94; SBP >105 to ≤115 mm Hg; HR: 0.78; 95% CI: 0.60 to 1.02; SBP >115 to ≤125 mm Hg; HR: 0.71; 95% CI: 0.53 to 0.94; SBP >125 to ≤135 mm Hg; HR: 0.79; 95% CI: 0.57 to 1.10; and SBP > 135 mm Hg; HR: 0.67; 95% CI: 0.50 to 0.90; p for interaction = 0.95). Hypotension was infrequent and not more common with MRA therapy than with placebo, overall (4.6% vs. 3.9%; p = 0.25) or in any SBP category. ConclusionsMRA treatment had little effect on SBP in patients with HFrEF, and the clinical benefits were not modified by baseline SBP. MRA treatment infrequently caused hypotension, even when the baseline SBP was low. The treatment discontinuation rates between MRA and placebo therapy were similar. Low SBP is not a reason to withhold MRA therapy in patients with HFrEF.

Aldosterone, the Mineralocorticoid Receptor and Mechanisms of Cardiovascular Disease.

The mineralocorticoid receptor (MR) and aldosterone play a critical role in the regulation of plasma volume homeostasis and are critical for the control of normal physiological regulation blood pressure (BP) and organ perfusion and as a potent mediator of hypertension. Aldosterone and the MR also play a key role in regulating tissue volume expansion in many tissues, via the regulation of hypertrophy and/or hyperplasia of cardiac or vascular smooth muscle cells and through regulation of the extra cellular matrix (ECM) and tissue fibrosis. Over the last two decades since the Randomized ALdactone Evaluation Study (RALES) trial it has become apparent that increased MR signaling is much more than electrolyte homeostasis and plasma volume. RALES demonstrated a key protective effect of MRA in severe heart failure and stimulated significant new research to understand the actions of the MR and its ligands on the heart and vascular system, the outcomes of which will be discussed in this chapter.

Impact of mineralocorticoid receptor antagonists on the risk of sudden cardiac death in patients with heart failure and left-ventricular systolic dysfunction: an individual patient-level meta-analysis of three randomized-controlled trials

Sudden cardiac death (SCD) is an important cause of death in patients with left-ventricular systolic dysfunction (LVSD). Mineralocorticoid receptor antagonists (MRAs) may attenuate this risk. We aimed to assess the impact of MRAs on SCD in patients with LVSD. A fixed-effect meta-analysis at individual patient-level was performed using 11,032 patients recruited in three placebo-controlled randomized trials: Randomized Aldactone Evaluation Study (RALES), Eplerenone Post Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS), and Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure (EMPHASIS-HF). Treatment effect was determined using a Cox proportional hazards model stratified by study. Patients receiving MRAs were at lower risk of SCD compared with placebo-treated patients after a mean follow-up of 18months (HR 0.77, 95% CI 0.66-0.89). This effect was consistent across trials and did not change substantially after adjustment for 14 baseline co-variates. Moreover, the benefits of MRAs were consistent across study subgroups, except for a greater effect in those < 65years old and those using beta-blockers. Using stratified analyses, we also found a consistent effect in relevant subsets of patient defined by heart failure cause, NYHA class or LVEF ≤ 35%. MRAs reduce the risk for SCD by 23% in patients with heart failure and LVSD. In these patients, the use of MRAs, on top of other evidence-based medications, should be optimized. It might be useful to re-assess the benefit of implantable cardiac defibrillator (ICD) placement, as ICD treatment effect was evaluated in trials enrolling patients not receiving MRAs.

Does aspirin detract from the benefits of mineralocorticoid receptor antagonists in patients with heart failure and a reduced left ventricular ejection fraction? Probably!

Does aspirin detract from the benefits of mineralocorticoid receptor antagonists in patients with heart failure and a reduced left ventricular ejection fraction? Probably!

Uncovering a Mineralocorticoid Receptor-Dependent Adipose-Vascular Axis: Implications for Vascular Dysfunction in Obesity?

Obesity, insulin resistance, and type 2 diabetes mellitus (T2DM) are associated with increased levels of aldosterone and activation of cardiovascular mineralocorticoid receptors (MRs) contributing to hypertension and associated cardiovascular disease (CVD) (1). Large randomized controlled trials such as the Randomized Aldactone Evaluation Study (RALES), the Epleronone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS), and the Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure (EMPHASIS-HF) have demonstrated the CVD-related mortality and morbidity benefits of MR antagonists, further implicating MR signaling as a key mediator of CVD (2). The actions of kidney MR signaling to increase cardiovascular and renal fibrosis and blood pressure is well known; however, recent research suggests that inappropriate activation of extrarenal MR signaling in vascular endothelial cells (ECs), vascular smooth muscle cells (VSMCs), immune cells, and adipocytes promotes insulin resistance, T2DM, and associated CVD (1,3,4). For example, in association with obesity and insulin resistance, perivascular and visceral adipose tissue (PVAT and VAT) is dysfunctional, in part, because of adipose MR activation (3). Furthermore, PVAT and VAT secrete aldosterone, the ligand for MRs in endothelial and smooth muscle cells, and this is increased in obesity (3, …

TORASEMIDE SAFETY IN COMPLEX THERAPY OF CHRONIC CARDIAC INSUFFICIENCY: RESULTS OF RANDOMIZED CROSS STUDY

In therapy of patients with chronic cardiac insufficiency we must use obligatory drugs as angiotensin-converting enzyme inhibitors (ACE inhibitors)/sartans, β-antagonists and mineral- corticoid receptor antagonists (MCRA). As is known, ACE inhibitors and MCRA can lead to potassium retention in the human body [1, 2]. Fear of hyperkalemia development in patients might increase due to the fact that the majority of patients are older than 60 and they might have disturbances of the kidney function. Nevertheless, data provided by R. Pisoni [3], testify about not frequent development of hyperkalemia in patients with chronic renal disease and use in therapy of spironolactone. Results of the study RALES (Randomized Aldactone Evaluation Study) [4] showed that inclusion in the therapy of spironactone had advantages compared to therapy without pironolactone in patients with cardiac insufficiency and reduced GFR.

Post hoc subgroups in clinical trials: Anathema or analytics?

There is currently much interest in generating more individualized estimates of treatment effects. However, traditional statistical methods are not well suited to this task. Post hoc subgroup analyses of clinical trials are fraught with methodological problems. We suggest that the alternative research paradigm of predictive analytics, widely used in many business contexts, can be adapted to help. We compare the statistical and analytics perspectives and suggest that predictive modeling should often replace subgroup analysis. We then introduce a new approach, cadit modeling, that can be useful to identify and test individualized causal effects. The cadit technique is particularly useful in the context of selecting from among a large number of potential predictors. We describe a new variable-selection algorithm that has been applied in conjunction with cadit. The cadit approach is illustrated through a reanalysis of data from the Randomized Aldactone Evaluation Study trial, which studied the efficacy of spironolactone in heart-failure patients. The trial was successful, but a serious adverse effect (hyperkalemia) was subsequently discovered. Our reanalysis suggests that it may be possible to predict the degree of hyperkalemia based on a logistic model and to identify a subgroup in which the effect is negligible. Cadit modeling is a promising alternative to subgroup analyses. Cadit regression is relatively straightforward to implement, generates results that are easy to present and explain, and can mesh straightforwardly with many variable-selection algorithms.

Incidence, predictors, and outcomes related to hypo- and hyperkalemia in patients with severe heart failure treated with a mineralocorticoid receptor antagonist.

Mineralocorticoid receptor antagonists reduce morbidity and mortality in patients with heart failure but can cause hyperkalemia, which contributes to reduced use of these drugs. Hypokalemia also leads to worse outcomes in patients with heart failure and may be attenuated by mineralocorticoid receptor antagonists. We assessed incidence and predictors of hyperkalemia (potassium ≥5.5 mmol/L) and hypokalemia (potassium <3.5 mmol/L) and the relationship to outcomes in 1663 patients with class III or IV heart failure and left ventricular ejection fraction <35% randomized to treatment with spironolactone 25 mg or placebo in the Randomized Aldactone Evaluation Study (RALES) trial. All-cause mortality rates and the influence of potassium levels on the effectiveness of spironolactone were assessed in a landmark analysis and in relation to time-varying potassium levels. After 1 month, mean potassium levels increased in the spironolactone group but not in the placebo group (4.54±0.49 versus 4.28±0.50 mmol/L; P<0.001) and remained elevated during the trial. Although the extremes of hypokalemia and hyperkalemia at 4 weeks were associated with increased risk of mortality in both treatment arms, participants in the spironolactone arm had lower mortality rates at all potassium levels throughout the duration of the trial. The treatment benefit of spironolactone was maintained at least until potassium exceeded 5.5 mmol/L. With appropriate surveillance of potassium and creatinine, the use of spironolactone was associated with less hypokalemia and improved survival in patients with severe heart failure even in the setting of moderate hyperkalemia.

Mineralocorticoid receptor antagonists and therapeutic strategies of cardiovascular damage

In recent years, much attention has focused on the role of aldosterone and mineralocorticoid receptors (MRs) in the pathophysiology of hypertension and cardiovascular disease. Patients with primary aldosteronism, in whom angiotensin II levels are low, have a higher incidence of cardiovascular complications than patients with essential hypertension. The Randomized Aldactone Evaluation Study (RALES) demonstrated that adding a non-specific MR antagonist, spironolactone, to a standard therapy that included angiotensin-converting enzyme (ACE) inhibitors, loop diuretics, and digoxin, significantly reduced morbidity and mortality in patients with moderate to severe heart failure. Similarly, the Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) showed that the addition of a selective MR antagonist (ARM), eplerenone, to an optimal medical therapy reduces morbidity and mortality among patients with acute myocardial infarction complicated by left ventricular dysfunction and heart failure. These data suggest that aldosterone induces cardiac injury through activation of MRs and support the notion that MR blockade has beneficial effects on aldosterone-dependent cardiac injury, through mechanisms that cannot be simply explained by hemodynamic changes. Although, MRA are highly effective in patients with heart failure, the risk of hyperkalemia should not be overlooked. Serious hyperkalemia events were reported in some MRA clinical trials; however these risks can be mitigated through appropriate patient selection, dose selection, patient education, monitoring, and follow-up.

Mineralocorticoid Receptor, the Main Player in Aldosterone-Induced Large Artery Stiffness

See related article, p 520–526 Aldosterone, a key hormone in the control of sodium and potassium balance, regulates extracellular volume and blood pressure. In the kidney, aldosterone, released by adrenal glomerulosa in response to angiotensin II, high potassium levels, and adrenocorticotropic hormone, classically acts through the mineralocorticoid receptor (MR), a ligand-activated transcription factor. The extensive expression of the MR in the cardiovascular system, including in the heart, endothelial cells, vascular smooth muscle cells, and mesangial cells, provides supportive evidence for a role of aldosterone in renal and cardiovascular injuries. Excess mineralocorticoid, in the context of inappropriate salt status, is a mediator of cardiac fibrosis, left ventricular hypertrophy, and hypertension, in a blood pressure–independent manner.1 The role of aldosterone in cardiovascular remodeling is emphasized in patients with primary hyperaldosteronism type 1 (also called glucocorticoid remediable hyperaldosteronism) where cardiac and vascular damages precede the development of hypertension.2 MR blockers have been shown to prevent vascular fibrosis, hypertrophic remodeling, inflammation, and impaired vascular reactivity in a blood pressure–independent manner in animal models of hypertension1 and vascular fibrosis in hypertensive patients stage 1.3 The demonstration of the benefits of MR blockade in chronic heart failure and hypertension emphasizes the importance of MR signaling pathways in cardiac and hypertensive diseases. Indeed, in patients with severe chronic heart failure, in addition to standard care, which included angiotensin-converting enzyme blockers or angiotensin II receptor blockers, spironolactone has been associated with a 30% improvement in survival (RALES [Randomized ALdactone Evaluation Study]).1 Similar observation has been made with eplerenone added to standard care in heart failure after myocardial infarction (EPHESUS [Eplerenone post-Acute Myocardial Infarction heart failure Efficacy and Survival …

Mineralocorticoid receptor and cardiac arrhythmia

Mineralocorticoid receptor (MR) activation has been shown to play a deleterious role in the development of heart disease in studies using specific MR antagonists (spironolactone, eplerenone) in both experimental models and patients. Pharmacological MR blockade attenuates the transition to heart failure (HF) in models of systolic left ventricular dysfunction and myocardial infarction, as well as diastolic dysfunction, in rats and mice. In humans, MR antagonism is highly beneficial in patients with mild or advanced HF and postinfarct HF. The consequences of aldosterone and MR activation for cardiac arrhythmia and its prevention and/or correction by MR antagonists are often underestimated. Activation of MR modulates cardiac electrical activity, causing atrial and ventricular arrhythmias. A pro-arrhythmogenic effect of aldosterone (possibly partly dependent on fibrosis) has been suggested by several studies. Cardiac MR activation has important consequences for the control of cellular calcium homeostasis, action potential lengthening, modulation of calcium transients and sarcoplasmic reticulum diastolic leaks, resulting in the promotion of rhythm disorders. Aldosterone and/or MR activation (in both cardiomyocytes and coronary vessels) result in vascular dysfunction and also contribute to pro-arrhythmogenic conditions. Together, the pro-arrhythmic effects of aldosterone and/or MR may explain the highly beneficial effect of MR antagonism, namely a decrease in the incidence of sudden death, observed in the Randomized Aldactone Evaluation Study (RALES) and Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) studies.

Race Influences the Safety and Efficacy of Spironolactone in Severe Heart Failure

The incidence of hyperkalemia caused by mineralocorticoid receptor antagonists may vary by race, but whether race influences efficacy of mineralocorticoid receptor antagonists in heart failure (HF) is unknown. We assessed hyperkalemia and outcomes in African Americans (AAs; n=120) and non-AAs (n=1543; white 93%) with New York Heart Association (NYHA) class III or IV HF and left ventricular dysfunction who were randomized to spironolactone, titrated to 25 or 50 mg daily or placebo, in the Randomized Aldactone Evaluation Study (RALES). AA participants were significantly younger, less likely to have an ischemic HF pathogenesis, more likely to be NYHA functional class IV, and more likely to have a higher estimated glomerular filtration rate and heart rate, less hypertension, diabetes mellitus, or history of myocardial infarction compared with non-AA participants. Potassium increased with spironolactone in non-AAs (4.29±0.5-4.55±0.49 mmol/L) but not in AAs (4.32±0.54-4.31±0.49 mmol/L; race by treatment interaction, P=0.03) during the first month and remained higher throughout the trial. Compared with AAs, non-AAs were more likely to attain maximal spironolactone dose (13.9% versus 5.8%; P=0.04) and had higher rates of hyperkalemia (potassium>5.5 mmol/L; 9.7% versus 4.2%; P<0.046), as well as lower rates of hypokalemia (potassium<3.5 mmol/L; 5.6% versus 17.9%; P<0.001). After adjustment for differences in baseline characteristics and achieved study drug dose, spironolactone reduced the combined end point of death or hospitalization for HF in non-AAs (hazard ratio, 0.63; 95% confidence interval, 0.55-0.73) but not in AAs (hazard ratio, 1.07; 95% confidence interval, 0.67-1.71; P value for interaction=0.032). AAs with HF exhibited less hyperkalemia and more hypokalemia with spironolactone compared with non-AAs and seemed to derive less clinical benefit. These hypothesis-generating findings suggest that safety and efficacy of mineralocorticoid receptor antagonists may differ by race.

Association Between Bilirubin and Mode of Death in Severe Systolic Heart Failure

The bilirubin level has been associated with worse outcomes, but it has not been studied as a predictor for the mode of death in patients with systolic heart failure. The Prospective Randomized Amlodipine Evaluation Study (PRAISE) cohort (including New York Heart Association class IIIB-IV patients with left ventricular ejection fraction <30%, n = 1,135) was analyzed, divided by bilirubin level: ≤0.6 mg/dl, group 1; >0.6 to 1.2 mg/dl, group 2; and >1.2 mg/dl, group 3. Multivariate Cox proportional hazards models were used to determine the association of bilirubin with the risk of sudden or pump failure death. Total bilirubin was entered as a base 2 log-transformed variable (log2 bilirubin), indicating doubling of the bilirubin level corresponding to each increase in variable value. The higher bilirubin groups had a lower ejection fraction (range 19% to 21%), sodium (range 138 to 139 mmol/L), and systolic blood pressure (range 111 to 120 mm Hg), a greater heart rate (range 79 to 81 beats/min), and greater diuretic dosages (range 86 to 110 furosemide-equivalent total daily dose in mg). The overall survival rates declined with increasing bilirubin (24.3, 31.3, and 44.3 deaths per 100 person-years, respectively, for groups 1, 2, and 3). Although a positive relation was seen between log2 bilirubin and both pump failure risk and sudden death risk, the relation in multivariate modeling was significant only for pump failure mortality (hazard ratio 1.47, 95% confidence interval 1.19 to 1.82, p = 0.0004), not for sudden death mortality (hazard ratio 1.21, 95% confidence interval 0.98 to 1.49, p = 0.08). In conclusion, an increasing bilirubin level was significantly associated with the risk of pump failure death but not for sudden death in patients with severe systolic heart failure.

Influence of Baseline and Worsening Renal Function on Efficacy of Spironolactone in Patients With Severe Heart Failure: Insights From RALES (Randomized Aldactone Evaluation Study)

This study investigated the influence of baseline and worsening renal function (WRF) on the efficacy of spironolactone in patients with severe heart failure (HF). Renal dysfunction or decline in renal function is a known predictor of adverse outcome in patients with HF, and treatment decisions are often on the basis of measures of renal function. We used data from the RALES (Randomized Aldactone Evaluation Study) in 1,658 patients with New York Heart Association functional class III or IV HF and an ejection fraction <35%. Participants were randomized to spironolactone 25 mg, which could be titrated to 50 mg, or placebo daily. Renal function (estimated glomerular filtration rate [eGFR]) was estimated by the Modification of Diet in Renal Disease equation. Worsening renal function was defined as a 30% reduction in eGFR from baseline to 12 weeks post-randomization. Individuals with reduced baseline eGFR exhibited similar relative risk reductions in all-cause death and the combined endpoint of death or hospital stays for HF as those with a baseline eGFR >60 ml/min/1.73 m(2) and greater absolute risk reduction compared with those with a higher baseline eGFR (10.3% vs. 6.4%). Moreover, WRF (17% vs. 7% for spironolactone and placebo groups, p < 0.001) was associated with an increased adjusted risk of death in the placebo group (hazard ratio: 1.9, 95% confidence interval: 1.3 to 2.6) but not in those randomized to spironolactone (hazard ratio: 1.1, 95% confidence interval: 0.79 to 1.5, p interaction = 0.009). The risk of hyperkalemia and renal failure was higher in those with worse baseline renal function and those with WRF, particularly in the spironolactone arm, but the substantial net benefit of spironolactone therapy remained. The absolute benefit of spironolactone was greatest in patients with reduced eGFR. Worsening renal function was associated with a negative prognosis, yet the mortality benefit of spironolactone was maintained.

Mineralocorticoid Receptor Antagonists and Mortality in Heart Failure With Concurrent Atrial Fibrillation

Aldosterone is the major mineralocorticoid in the human body and is produced in the zona glomerulosa of the cortex in the adrenal glands, and its secretion is stimulated by angiotensin II, adrenocorticotrophic hormone, catecholamines, and local potassium levels. Its levels in plasma are elevated 4-fold in heart failure (HF).1 Through a variety of mechanisms, aldosterone is believed to play a role in the pathogenesis and progression of left ventricular dysfunction.2 The mineralocorticoid receptor antagonists (MRAs) spironolactone and eplerenone have consistently demonstrated a 20% reduction in mortality and 21% reduction in sudden death, which has been counterbalanced by a 6% to 12% risk of hyperkalemia (potassium >6.0 mEq/L) depending on the baseline estimated glomerular filtration rate.3,4,5 Article see p 586 In this issue of Circulation: Heart Failure , O’Meara and colleagues report on a retrospective analysis from …

Stopping a trial early – and then what?

This article addresses a problem arising when a trial shows such strong evidence of benefit of the tested intervention that it stops early with an observed effect size for the experimental treatment that is statistically significantly better than the control. Within the classical frequentist framework of group sequential trials, the observed estimated effect size, the associated naïve confidence interval, and the p-value are all biased estimates of the true values. The bias is in the direction of the overestimation of the treatment effect, creation of narrower confidence intervals than appropriate, and a p-value that is too small. To discuss methods for correcting the bias in observed effect sizes, confidence intervals, and p-values for trials stopped early and to show the extent to which such correction would have modified the conclusions of the Randomized Aldactone Evaluation Study (RALES). In RALES, the effect of not correcting for bias is negligible. This article does not show general results; it only explores a few examples that use conservative methods for early stopping. It does not consider sequential methods that allow a relatively high probability of stopping early. This article points out that there is no unique solution to the correction of the p-value, but it recommends stagewise ordering, which states that earlier stopping of a trial is ipso facto stronger evidence of effect than later stopping so long as the stopping is governed by a monitoring boundary that preserves the Type I error rate. Associated with stagewise ordering is a method for calculating the estimated effect size and its confidence interval. In the RALES trial, which stopped at 50% information time, the corrections to the estimated values are small.