Redefining Iron Deficiency in Patients With Chronic Heart Failure.

A serum ferritin level <15 to 20 µg/L historically identified patients who had absent bone marrow iron stores, but serum ferritin levels are distorted by the systemic inflammatory states seen in patients with chronic kidney disease or heart failure. As a result, nearly 25 years ago, the diagnostic ferritin threshold was increased 5- to 20-fold in patients with chronic kidney disease (ie, iron deficiency was identified if the serum ferritin level was <100 µg/L, regardless of transferrin saturation [TSAT], or 100 to 299 µg/L if TSAT was <20%). This guidance was motivated not by the findings of studies of total body or tissue iron depletion, but by a desire to encourage the use of iron supplements to potentiate the response to erythropoiesis-stimulating agents in patients with renal anemia. However, in patients with heart failure, this definition does not reliably identify patients with an absolute or functional iron-deficiency state, and it includes individuals with TSATs (≥20%) and serum ferritin levels in the normal range (20-100 mg/L) who are not iron deficient, have an excellent prognosis, and do not respond favorably to iron therapy. Furthermore, serum ferritin levels may be distorted by the use of both neprilysin and sodium-glucose cotransporter 2 inhibitors, both of which may act to mobilize endogenous iron stores. The most evidence-based and trial-tested definition of iron deficiency is the presence of hypoferremia, as reflected by as a TSAT <20%. These hypoferremic patients are generally iron deficient on bone marrow examination, and after intravenous iron therapy, they exhibit an improvement in exercise tolerance and functional capacity (when meaningfully impaired) and show the most marked reduction (ie, 20%-30%) in the risk of cardiovascular death or total heart failure hospitalizations. Therefore, we propose that the current ferritin-driven definition of iron deficiency in heart failure should be abandoned and that a definition based on hypoferremia (TSAT <20%) should be adopted.

Effect of Sacubitril/Valsartan on Cognitive Function in Patients With Heart Failure With Preserved Ejection Fraction: A Prespecified Analysis of PARAGON-HF.

BACKGROUND: A hypothetical concern has been raised that sacubitril/valsartan might cause cognitive impairment because neprilysin is one of several enzymes degrading amyloid-ß peptides in the brain, some of which are neurotoxic and linked to Alzheimer-type dementia. To address this, we examined the effect of sacubitril/valsartan compared with valsartan on cognitive function in patients with heart failure with preserved ejection fraction in a prespecified substudy of PARAGON-HF (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Global Outcomes in Heart Failure With Preserved Ejection Fraction). METHODS: In PARAGON-HF, serial assessment of cognitive function was conducted in a subset of patients with the Mini-Mental State Examination (MMSE; score range, 0-30, with lower scores reflecting worse cognitive function). The prespecified primary analysis of this substudy was the change from baseline in MMSE score at 96 weeks. Other post hoc analyses included cognitive decline (fall in MMSEs score of ≥3 points), cognitive impairment (MMSE score <24), or the occurrence of dementia-related adverse events. RESULTS: Among 2895 patients included in the MMSE substudy with baseline MMSE score measured, 1453 patients were assigned to sacubitril/valsartan and 1442 to valsartan. Their mean age was 73 years, and the median follow-up was 32 months. The mean±SD MMSE score at randomization was 27.4±3.0 in the sacubitril/valsartan group, with 10% having an MMSE score <24; the corresponding numbers were nearly identical in the valsartan group. The mean change from baseline to 96 weeks in the sacubitril/valsartan group was -0.05 (SE, 0.07); the corresponding change in the valsartan group was -0.04 (0.07). The mean between-treatment difference at week 96 was -0.01 (95% CI, -0.20 to 0.19; P=0.95). Analyses of a ≥3-point decline in MMSE, decrease to a score <24, dementia-related adverse events, and combinations of these showed no difference between sacubitril/valsartan and valsartan. No difference was found in the subgroup of patients tested for apolipoprotein E ε4 allele genotype. CONCLUSIONS: Patients with heart failure with preserved ejection fraction in PARAGON-HF had relatively low baseline MMSE scores. Cognitive change, measured by MMSE, did not differ between treatment with sacubitril/valsartan and treatment with valsartan in patients with heart failure with preserved ejection fraction. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01920711.

Sodium-Glucose Cotransporter-2 Inhibitors and Major Adverse Cardiovascular Outcomes: A SMART-C Collaborative Meta-Analysis.

BACKGROUND: Sodium-glucose cotransporter-2 inhibitors (SGLT2i) consistently improve heart failure and kidney-related outcomes; however, effects on major adverse cardiovascular events (MACE) across different patient populations are less clear. METHODS: This was a collaborative trial-level meta-analysis from the SGLT2i Meta-analysis Cardio-Renal Trialists Consortium, which includes all phase 3, placebo-controlled, outcomes trials of SGLT2i across 3 patient populations (patients with diabetes at high risk for atherosclerotic cardiovascular disease, heart failure [HF], or chronic kidney disease). The outcomes of interest were MACE (composite of cardiovascular death, myocardial infarction , or stroke), individual components of MACE (inclusive of fatal and nonfatal events), all-cause mortality, and death subtypes. Effect estimates for SGLT2i versus placebo were meta-analyzed across trials and examined across key subgroups (established atherosclerotic cardiovascular disease, previous myocardial infarction, diabetes, previous HF, albuminuria, chronic kidney disease stages, and risk groups). RESULTS: A total of 78 607 patients across 11 trials were included: 42 568 (54.2%), 20 725 (26.4%), and 15 314 (19.5%) were included from trials of patients with diabetes at high risk for atherosclerotic cardiovascular disease, HF, or chronic kidney disease, respectively. SGLT2i reduced the rate of MACE by 9% (hazard ration [HR], 0.91 [95% CI, 0.87-0.96], P<0.0001) with a consistent effect across all 3 patient populations (I2=0%) and across all key subgroups. This effect was primarily driven by a reduction in cardiovascular death (HR, 0.86 [95% CI, 0.81-0.92], P<0.0001), with no significant effect for myocardial infarction in the overall population (HR, 0.95 [95% CI, 0.87-1.04], P=0.29), and no effect on stroke (HR, 0.99 [95% CI, 0.91-1.07], P=0.77). The benefit for cardiovascular death was driven primarily by reductions in HF death and sudden cardiac death (HR, 0.68 [95% CI, 0.46-1.02] and HR, 0.86 [95% CI, 0.78-0.95], respectively) and was generally consistent across subgroups, with the possible exception of being more apparent in those with albuminuria (Pinteraction=0.02). CONCLUSIONS: SGLT2i reduce the risk of MACE across a broad range of patients irrespective of atherosclerotic cardiovascular disease, diabetes, kidney function, or other major clinical characteristics at baseline. This effect is driven primarily by a reduction of cardiovascular death, particularly HF death and sudden cardiac death, without a significant effect on myocardial infarction in the overall population, and no effect on stroke. These data may help inform selection for SGLT2i therapies across the spectrum of cardiovascular-kidney-metabolic disease.

Identification of three mechanistic pathways for iron-deficient heart failure.

Current understanding of iron-deficient heart failure is based on blood tests that are thought to reflect systemic iron stores, but the available evidence suggests greater complexity. The entry and egress of circulating iron is controlled by erythroblasts, which (in severe iron deficiency) will sacrifice erythropoiesis to supply iron to other organs, e.g. the heart. Marked hypoferraemia (typically with anaemia) can drive the depletion of cardiomyocyte iron, impairing contractile performance and explaining why a transferrin saturation < ≈15%-16% predicts the ability of intravenous iron to reduce the risk of major heart failure events in long-term trials (Type 1 iron-deficient heart failure). However, heart failure may be accompanied by intracellular iron depletion within skeletal muscle and cardiomyocytes, which is disproportionate to the findings of systemic iron biomarkers. Inflammation- and deconditioning-mediated skeletal muscle dysfunction-a primary cause of dyspnoea and exercise intolerance in patients with heart failure-is accompanied by intracellular skeletal myocyte iron depletion, which can be exacerbated by even mild hypoferraemia, explaining why symptoms and functional capacity improve following intravenous iron, regardless of baseline haemoglobin or changes in haemoglobin (Type 2 iron-deficient heart failure). Additionally, patients with advanced heart failure show myocardial iron depletion due to both diminished entry into and enhanced egress of iron from the myocardium; the changes in iron proteins in the cardiomyocytes of these patients are opposite to those expected from systemic iron deficiency. Nevertheless, iron supplementation can prevent ventricular remodelling and cardiomyopathy produced by experimental injury in the absence of systemic iron deficiency (Type 3 iron-deficient heart failure). These observations, taken collectively, support the possibility of three different mechanistic pathways for the development of iron-deficient heart failure: one that is driven through systemic iron depletion and impaired erythropoiesis and two that are characterized by disproportionate depletion of intracellular iron in skeletal and cardiac muscle. These mechanisms are not mutually exclusive, and all pathways may be operative at the same time or may occur sequentially in the same patients.

Critical Analysis of the Effects of SGLT2 Inhibitors on Renal Tubular Sodium, Water and Chloride Homeostasis and Their Role in Influencing Heart Failure Outcomes.

SGLT2 (sodium-glucose cotransporter 2) inhibitors interfere with the reabsorption of glucose and sodium in the early proximal renal tubule, but the magnitude and duration of any ensuing natriuretic or diuretic effect are the result of an interplay between the degree of upregulation of SGLT2 and sodium-hydrogen exchanger 3, the extent to which downstream compensatory tubular mechanisms are activated, and (potentially) the volume set point in individual patients. A comprehensive review and synthesis of available studies reveals several renal response patterns with substantial variation across studies and clinical settings. However, the common observation is an absence of a large acute or chronic diuresis or natriuresis with these agents, either when given alone or combined with other diuretics. This limited response results from the fact that renal compensation to these drugs is rapid and nearly complete within a few days or weeks, preventing progressive volume losses. Nevertheless, the finding that fractional excretion of glucose and lithium (the latter being a marker of proximal sodium reabsorption) persists during long-term treatment with SGLT2 inhibitors indicates that pharmacological tolerance to the effects of these drugs at the level of the proximal tubule does not meaningfully occur. This persistent proximal tubular effect of SGLT2 inhibitors can be hypothesized to produce a durable improvement in the internal set point for volume homeostasis, which may become clinically important during times of fluid expansion. However, it is difficult to know whether a treatment-related change in the volume set point actually occurs or contributes to the effect of these drugs to reduce the risk of major heart failure events. SGLT2 inhibitors exert cardioprotective effects by a direct effect on cardiomyocytes that is independent of the presence of or binding to SGLT2 or the actions of these drugs on the proximal renal tubule. Nevertheless, changes in the volume set point mediated by SGLT2 inhibitors might potentially act cooperatively with the direct favorable molecular and cellular effects of these drugs on cardiomyocytes to mediate their benefits on the development and clinical course of heart failure.

Blinded Withdrawal of Long-Term Randomized Treatment With Empagliflozin or Placebo in Patients With Heart Failure.

BACKGROUND: It is not known whether the benefits of sodium-glucose cotransporter 2 inhibitors in heart failure persist after years of therapy. METHODS: In the EMPEROR-Reduced (Empagliflozin Outcome Trials in Chronic Heart Failure With Reduced Ejection Fraction) and EMPEROR-Preserved (Empagliflozin Outcome Trials in Chronic Heart Failure With Preserved Ejection Fraction) trials, patients with heart failure were randomly assigned (double-blind) to placebo or empagliflozin 10 mg/day for a median of 16 and 26 months, respectively. At the end of the trials, 6799 patients (placebo 3381, empagliflozin 3418) were prospectively withdrawn from treatment in a blinded manner, and, of these, 3981 patients (placebo 2020, empagliflozin 1961) underwent prespecified in-person assessments after ≈30 days off treatment. RESULTS: From 90 days from the start of closeout to the end of double-blind treatment, the annualized risk of cardiovascular death or hospitalization for heart failure was lower in empagliflozin-treated patients than in placebo-treated patients (10.7 [95% CI, 9.0-12.6] versus 13.5 [95% CI, 11.5-15.6] events per 100 patient-years, respectively; hazard ratio 0.76 [95% CI, 0.60-0.96]). When the study drugs were withdrawn for ≈30 days, the annualized risk of cardiovascular death or hospitalization for heart failure increased in patients withdrawn from empagliflozin but not in those withdrawn from placebo (17.0 [95% CI, 12.6-22.1] versus 14.1 [95% CI, 10.1-18.8] events per 100 patient-years for empagliflozin and placebo, respectively). The hazard ratio for the change in risk in the patients withdrawn from empagliflozin was 1.75 (95% CI, 1.20-2.54), P=0.0034, whereas the change in the risk in patients withdrawn from placebo was not significant (hazard ratio 1.12 [95% CI, 0.76-1.66]); time period-by-treatment interaction, P=0.068. After withdrawal, the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score declined by 1.6±0.4 in patients withdrawn from empagliflozin versus placebo (P<0.0001). Furthermore, withdrawal of empagliflozin was accompanied by increases in fasting glucose, body weight, systolic blood pressure, estimated glomerular filtration rate, N-terminal pro-hormone B-type natriuretic peptide, uric acid, and serum bicarbonate and decreases in hemoglobin and hematocrit (all P<0.01). These physiological and laboratory changes were the inverse of the effects of the drug seen at the start of the trials during the initiation of treatment (≈1-3 years earlier) in the same cohort of patients. CONCLUSIONS: These observations demonstrate a persistent effect of empagliflozin in patients with heart failure even after years of treatment, which dissipated rapidly after withdrawal of the drug. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifiers: NCT03057977 and NCT03057951.

Clinical Characteristics and Outcomes in Patients With Heart Failure: Are There Thresholds and Inflection Points in Left Ventricular Ejection Fraction and Thresholds Justifying a Clinical Classification?

BACKGROUND: Recent guidelines proposed a classification for heart failure (HF) on the basis of left ventricular ejection fraction (LVEF), although it remains unclear whether the divisions chosen were biologically rational. Using patients spanning the full range of LVEF, we examined whether there was evidence of LVEF thresholds in patient characteristics or inflection points in clinical outcomes. METHODS: Using patient-level information, we created a merged dataset of 33 699 participants who had been enrolled in 6 randomized controlled HF trials including patients with reduced and preserved ejection fraction. The relationship between the incidence of all-cause death (and specific causes of death) and HF hospitalization, and LVEF, was evaluated using Poisson regression models. RESULTS: As LVEF increased, age, the proportion of women, body mass index, systolic blood pressure, and prevalence of atrial fibrillation and diabetes increased, whereas ischemic pathogenesis, estimated glomerular filtration rate, and NT-proBNP (N-terminal pro-B-type natriuretic peptide) decreased. As LVEF increased >50%, age and the proportion of women continued to increase, and ischemic pathogenesis and NT-proBNP decreased, but other characteristics did not change meaningfully. The incidence of most clinical outcomes (except noncardiovascular death) decreased as LVEF increased, with a LVEF inflection point of around 50% for all-cause death and cardiovascular death, around 40% for pump failure death, and around 35% for HF hospitalization. Higher than those thresholds, there was little further decline in the incidence rate. There was no evidence of a J-shaped relationship between LVEF and death; no evidence of worse outcomes in patients with high-normal ("supranormal") LVEF. Similarly, in a subset of patients with echocardiographic data, there were no structural differences in patients with a high-normal LVEF suggestive of amyloidosis, and NT-proBNP levels were consistent with this conclusion. CONCLUSIONS: In patients with HF, there was a LVEF threshold of around 40% to 50% where the pattern of patient characteristics changed, and event rates began to increase compared with higher LVEF values. Our findings provide evidence to support current upper LVEF thresholds defining HF with mildly reduced ejection fraction on the basis of prognosis. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifiers: NCT00634309, NCT00634400, NCT00634712, NCT00095238, NCT01035255, NCT00094302, NCT00853658, and NCT01920711.

Empagliflozin in Heart Failure with a Preserved Ejection Fraction.

BACKGROUND: Sodium-glucose cotransporter 2 inhibitors reduce the risk of hospitalization for heart failure in patients with heart failure and a reduced ejection fraction, but their effects in patients with heart failure and a preserved ejection fraction are uncertain. METHODS: In this double-blind trial, we randomly assigned 5988 patients with class II-IV heart failure and an ejection fraction of more than 40% to receive empagliflozin (10 mg once daily) or placebo, in addition to usual therapy. The primary outcome was a composite of cardiovascular death or hospitalization for heart failure. RESULTS: Over a median of 26.2 months, a primary outcome event occurred in 415 of 2997 patients (13.8%) in the empagliflozin group and in 511 of 2991 patients (17.1%) in the placebo group (hazard ratio, 0.79; 95% confidence interval [CI], 0.69 to 0.90; P<0.001). This effect was mainly related to a lower risk of hospitalization for heart failure in the empagliflozin group. The effects of empagliflozin appeared consistent in patients with or without diabetes. The total number of hospitalizations for heart failure was lower in the empagliflozin group than in the placebo group (407 with empagliflozin and 541 with placebo; hazard ratio, 0.73; 95% CI, 0.61 to 0.88; P<0.001). Uncomplicated genital and urinary tract infections and hypotension were reported more frequently with empagliflozin. CONCLUSIONS: Empagliflozin reduced the combined risk of cardiovascular death or hospitalization for heart failure in patients with heart failure and a preserved ejection fraction, regardless of the presence or absence of diabetes. (Funded by Boehringer Ingelheim and Eli Lilly; EMPEROR-Preserved ClinicalTrials.gov number, NCT03057951).

Mechanistic and Clinical Comparison of the Erythropoietic Effects of SGLT2 Inhibitors and Prolyl Hydroxylase Inhibitors in Patients with Chronic Kidney Disease and Renal Anemia.

Renal anemia is treated with erythropoiesis-stimulating agents (ESAs), even though epoetin alfa and darbepoetin increase the risk of cardiovascular death and thromboembolic events, including stroke. Hypoxia-inducible factor prolyl hydroxylase domain (HIF-PHD) inhibitors have been developed as an alternative to ESAs, producing comparable increases in hemoglobin. However, in advanced chronic kidney disease, HIF-PHD inhibitors can increase the risk of cardiovascular death, heart failure, and thrombotic events to a greater extent than that with ESAs, indicating that there is a compelling need for safer alternatives. Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of major cardiovascular events, and they increase hemoglobin, an effect that is related to an increase in erythropoietin and an expansion in red blood cell mass. SGLT2 inhibitors increase hemoglobin by ≈0.6-0.7 g/dL, resulting in the alleviation of anemia in many patients. The magnitude of this effect is comparable to that seen with low-to-medium doses of HIF-PHD inhibitors, and it is apparent even in advanced chronic kidney disease. Interestingly, HIF-PHD inhibitors act by interfering with the prolyl hydroxylases that degrade both HIF-1α and HIF-2α, thus enhancing both isoforms. However, HIF-2α is the physiological stimulus to the production of erythropoietin, and upregulation of HIF-1α may be an unnecessary ancillary property of HIF-PHD inhibitors, which may have adverse cardiac and vascular consequences. In contrast, SGLT2 inhibitors act to selectively increase HIF-2α, while downregulating HIF-1α, a distinctive profile that may contribute to their cardiorenal benefits. Intriguingly, for both HIF-PHD and SGLT2 inhibitors, the liver is likely to be an important site of increased erythropoietin production, recapitulating the fetal phenotype. These observations suggest that the use of SGLT2 inhibitors should be seriously evaluated as a therapeutic approach to treat renal anemia, yielding less cardiovascular risk than other therapeutic options.

Impact of empagliflozin on insulin needs in patients with heart failure and diabetes: An EMPEROR-Pooled analysis.

AIM: To assess the effect of empagliflozin on patients with comorbid heart failure (HF) and diabetes with or without baseline insulin, and to study the impact of empagliflozin on insulin requirements over time. MATERIALS AND METHODS: We performed a post-hoc analysis of pooled patient-level data from two cardiovascular outcomes trials of empagliflozin in HF (EMPEROR-Reduced and EMPEROR-Preserved trials). We undertook a subgroup analysis stratified by baseline insulin use, including all patients with diabetes. The studied endpoints included the primary composite endpoint of first hospitalization for HF or cardiovascular death, rate of decline of estimated glomerular filtration rate, composite renal outcome and rates of sustained insulin initiation. RESULTS: Among 4794 patients with diabetes, 1333 (658 in empagliflozin, 675 in placebo) were using insulin at baseline. The treatment effect of empagliflozin on the primary endpoint was consistent irrespective of insulin use [no insulin, hazard ratio 0.74, 95% confidence interval (CI) 0.63-0.86; using insulin, hazard ratio 0.81, 95% CI 0.66-1.00, pinteraction = .49], as was the effect on the rate of decline of the estimated glomerular filtration rate (pinteraction = .75). There was no effect of empagliflozin on the composite renal outcome in patients using or not using insulin (pinteraction = .30). Among patients not using insulin at baseline, those randomized to empagliflozin initiated insulin less frequently throughout the follow-up period compared with those receiving placebo (2.6% vs. 3.8%, odds ratio 0.66, 95% CI 0.50-0.88). CONCLUSIONS: Empagliflozin exerts a consistent benefit on cardiovascular outcomes and renal function decline, irrespective of baseline insulin use, and reduces the need for sustained insulin initiation in patients with HF and diabetes.

Fetal Reprogramming of Nutrient Surplus Signaling, O-GlcNAcylation, and the Evolution of CKD.

ABSTRACT: Fetal kidney development is characterized by increased uptake of glucose, ATP production by glycolysis, and upregulation of mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1 alpha (HIF-1 α ), which (acting in concert) promote nephrogenesis in a hypoxic low-tubular-workload environment. By contrast, the healthy adult kidney is characterized by upregulation of sirtuin-1 and adenosine monophosphate-activated protein kinase, which enhances ATP production through fatty acid oxidation to fulfill the needs of a normoxic high-tubular-workload environment. During stress or injury, the kidney reverts to a fetal signaling program, which is adaptive in the short term, but is deleterious if sustained for prolonged periods when both oxygen tension and tubular workload are heightened. Prolonged increases in glucose uptake in glomerular and proximal tubular cells lead to enhanced flux through the hexosamine biosynthesis pathway; its end product-uridine diphosphate N -acetylglucosamine-drives the rapid and reversible O-GlcNAcylation of thousands of intracellular proteins, typically those that are not membrane-bound or secreted. Both O-GlcNAcylation and phosphorylation act at serine/threonine residues, but whereas phosphorylation is regulated by hundreds of specific kinases and phosphatases, O-GlcNAcylation is regulated only by O-GlcNAc transferase and O-GlcNAcase, which adds or removes N-acetylglucosamine, respectively, from target proteins. Diabetic and nondiabetic CKD is characterized by fetal reprogramming (with upregulation of mTOR and HIF-1 α ) and increased O-GlcNAcylation, both experimentally and clinically. Augmentation of O-GlcNAcylation in the adult kidney enhances oxidative stress, cell cycle entry, apoptosis, and activation of proinflammatory and profibrotic pathways, and it inhibits megalin-mediated albumin endocytosis in glomerular mesangial and proximal tubular cells-effects that can be aggravated and attenuated by augmentation and muting of O-GlcNAcylation, respectively. In addition, drugs with known nephroprotective effects-angiotensin receptor blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors-are accompanied by diminished O-GlcNAcylation in the kidney, although the role of such suppression in mediating their benefits has not been explored. The available evidence supports further work on the role of uridine diphosphate N -acetylglucosamine as a critical nutrient surplus sensor (acting in concert with upregulated mTOR and HIF-1 α signaling) in the development of diabetic and nondiabetic CKD.

Mechanisms of enhanced renal and hepatic erythropoietin synthesis by sodium-glucose cotransporter 2 inhibitors.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors reduce the risk of major heart failure events, an action that is statistically linked to enhanced erythropoiesis, suggesting that stimulation of erythropoietin and cardioprotection are related to a shared mechanism. Four hypotheses have been proposed to explain how these drugs increase erythropoietin production: (i) renal cortical reoxygenation with rejuvenation of erythropoietin-producing cells; (ii) counterregulatory distal sodium reabsorption leading to increased tubular workload and oxygen consumption, and thus, to localized hypoxia; (iii) increased iron mobilization as a stimulus of hypoxia-inducible factor-2α (HIF-2α)-mediated erythropoietin synthesis; and (iv) direct HIF-2α activation and enhanced erythropoietin gene transcription due to increased sirtuin-1 (SIRT1) signaling. The first two hypotheses assume that the source of increased erythropoietin is the interstitial fibroblast-like cells in the deep renal cortex. However, SGLT2 inhibitors do not alter regional tissue oxygen tension in the non-diabetic kidney, and renal erythropoietin synthesis is markedly impaired in patients with anemia due to chronic kidney disease, and yet, SGLT2 inhibitors produce an unattenuated erythrocytic response in these patients. This observation raises the possibility that the liver contributes to the production of erythropoietin during SGLT2 inhibition. Hypoxia-inducible factor-2α and erythropoietin are coexpressed not only in the kidney but also in hepatocytes; the liver is a major site of production when erythropoietin stimulation is maintained for prolonged periods. The ability of SGLT2 inhibitors to improve iron mobilization by derepressing hepcidin and ferritin would be expected to increase cytosolic ferrous iron, which might stimulate HIF-2α expression in both the kidney and liver through the action of iron regulatory protein 1. Alternatively, the established ability of SGLT2 inhibitors to enhance SIRT1 might be the mechanism of enhanced erythropoietin production with these drugs. In hepatic cell lines, SIRT1 can directly activate HIF-2α by deacetylation, and additionally, through an effect of SIRT in the liver, peroxisome proliferator-activated receptor-γ coactivator-1α binds to hepatic nuclear factor 4 to promote transcription of the erythropoietin gene and synthesis of erythropoietin. Since SIRT1 up-regulation exerts direct cytoprotective effects on the heart and stimulates erythropoietin, it is well-positioned to represent the shared mechanism that links erythropoiesis to cardioprotection during SGLT2 inhibition.

Empagliflozin, irrespective of blood pressure, improves outcomes in heart failure with preserved ejection fraction: the EMPEROR-Preserved trial.

AIMS: Empagliflozin reduces the risk of cardiovascular death or heart failure (HF) hospitalization in patients with HF and preserved ejection fraction. This study aims to evaluate if systolic blood pressure (SBP) moderates these effects. METHODS AND RESULTS: The association of SBP and the treatment effects of empagliflozin in EMPEROR-Preserved (empagliflozin outcome trial in patients with chronic heart failure with preserved ejection fraction) was evaluated. Randomized patients (n 5988) were grouped according to SBP at baseline (110 mmHg, n 455; 110130 mmHg, n 2415; 130 mmHg, n 3118). The effect of empagliflozin on blood pressure, cardiovascular death or HF hospitalization (primary outcome), total HF hospitalizations, and rate of decline in estimated glomerular filtration rate was studied. Over a median of 26.2 months, the placebo-corrected decline was small and not significantly different across baseline SBP. On placebo, the risk of cardiovascular death or hospitalization for HF was 8.58 at 130 mmHg, 8.26 at 110130 mmHg, and 11.59 events per 100 patient-years at 110 mmHg (P 0.12 vs. 130 mmHg, P 0.08 vs. 110130 mmHg). There was no evidence for baseline SBP moderating the effect of empagliflozin on risk of HF events (primary endpoint interaction P 0.69, recurrent HF hospitalizations interaction P 0.55). When comparing empagliflozin with placebo, SBP did not meaningfully associate with adverse events such as hypotension, volume depletion, and acute renal failure. CONCLUSION: In EMPEROR-Preserved, empagliflozin was effective and safe without SBP meaningfully moderating empagliflozins treatment effects. This analysis of EMPEROR-Preserved shows that empagliflozin can be used safely and effectively without blood pressure being a meaningful moderator of the drug benefit. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov Unique identifier: NCT03057951.

Anthropometric measures and adverse outcomes in heart failure with reduced ejection fraction: revisiting the obesity paradox.

AIMS: Although body mass index (BMI) is the most commonly used anthropometric measure, newer indices such as the waist-to-height ratio, better reflect the location and amount of ectopic fat, as well as the weight of the skeleton, and may be more useful. METHODS AND RESULTS: The prognostic value of several newer anthropometric indices was compared with that of BMI in patients with heart failure (HF) and reduced ejection fraction (HFrEF) enrolled in prospective comparison of ARNI with ACEI to determine impact on global mortality and morbidity in heart failure. The primary outcome was HF hospitalization or cardiovascular death. The association between anthropometric indices and outcomes were comprehensively adjusted for other prognostic variables, including natriuretic peptides. An 'obesity-survival paradox' related to lower mortality risk in those with BMI ≥25 kg/m2 (compared with normal weight) was identified but this was eliminated by adjustment for other prognostic variables. This paradox was less evident for waist-to-height ratio (as an exemplar of indices not incorporating weight) and eliminated by adjustment: the adjusted hazard ratio (aHR) for all-cause mortality, for quintile 5 vs. quintile 1, was 1.10 [95% confidence interval (CI) 0.87-1.39]. However, both BMI and waist-to-height ratio showed that greater adiposity was associated with a higher risk of the primary outcome and HF hospitalization; this was more evident for waist-to-height ratio and persisted after adjustment e.g. the aHR for HF hospitalization for quintile 5 vs. quintile 1 of waist-to-height ratio was 1.39 (95% CI 1.06-1.81). CONCLUSION: In patients with HFrEF, alternative anthropometric measurements showed no evidence for an 'obesity-survival paradox'. Newer indices that do not incorporate weight showed that greater adiposity was clearly associated with a higher risk of HF hospitalization.

Investigator-reported ventricular arrhythmias and mortality in heart failure with mildly reduced or preserved ejection fraction.

AIMS: Few reports have examined the incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) or their relationship with mortality in patients with heart failure with mildly reduced ejection fraction (HFmrEF) or heart failure with preserved ejection fraction (HFpEF). METHODS AND RESULTS: Data from the PARAGON-HF, TOPCAT, I-Preserve, and CHARM-Preserved trials were merged. VT/VF, reported as adverse events, were identified. Patients who experienced VT/VF were compared with patients who did not. The relationship between VT/VF and mortality was examined in time-updated Cox proportional hazard regression models. Variables associated with VT/VF were examined in Cox proportional hazard regression models. The rate of VT/VF in patients with HFmrEF compared with patients with HFpEF was examined in a Cox proportional hazards regression model. Of 13 609 patients, over a median follow-up of 1170 days (interquartile range: 966-1451), 146 (1.1%) experienced an investigator-reported VT/VF (incidence rate 0.3 per 100 person-years). Patients who experienced VT/VF were more likely to be male, have had a myocardial infarction, poorer renal function, more adverse left ventricular remodelling, and higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) than patients who did not. Occurrence of VT/VF was associated with NT-proBNP, history of atrial fibrillation/flutter, male sex, lower ejection fraction, and history of hypertension. VT/VF was associated with all-cause death [adjusted hazard ratio (HR): 3.95, 95% confidence interval (CI): 2.80-5.57; P < 0.001] and cardiovascular death, driven by death from heart failure and not sudden death. Patients with HFmrEF had a higher rate of VT/VF than patients with HFpEF (adjusted HR: 2.19, 95% CI: 1.77-2.71). CONCLUSION: VT/VF was uncommon in patients with HFmrEF and HFpEF. However, such events were strongly associated with mortality and appear to be a marker of disease severity rather than risk of sudden death. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov unique identifier: NCT01920711(PARAGON-HF); NCT00094302 (TOPCAT); NCT00095238 (I-Preserve); NCT00634712 (CHARM-Preserved).

Importance of cystatin C in estimating glomerular filtration rate: the PARADIGM-HF trial.

AIMS: The 2021 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation combining creatinine and cystatin C provides a better estimation of glomerular filtration rate (GFR) compared to the creatinine-only equation. METHODS AND RESULTS: CKD-EPI creatinine-cystatin C equation (creatinine-cystatin) was compared to creatinine-only (creatinine) equation in a subpopulation of Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure (PARADIGM-HF). Patients were categorized according to difference in eGFR using the two equations: Group 1 (<-10 mL/min/1.73 m2, i.e. creatinine-cystatin more than 10 mL/min lower than creatinine), Group 2 (>-10 and <10 mL/min/1.73 m2), and Group 3 (>10 mL/min/1.73 m2, i.e. creatinine-cystatin more than 10 mL/min higher than creatinine). Cystatin C and creatinine were available in 1966 patients at randomization. Median (interquartile range) eGFR difference was -0.7 (-6.4-4.8) mL/min/1.73 m2. Compared to creatinine, creatinine-cystatin led to a substantial reclassification of chronic kidney disease stages. Overall, 212 (11%) and 355 (18%) patients were reallocated to a better and worse eGFR category, respectively. Compared to patients in Group 2, those in Group 1 (lower eGFR with creatinine-cystatin) had higher mortality and those in Group 3 (higher eGFR with creatinine-cystatin) had lower mortality. Increasing difference in eGFR (due to lower eGFR with creatinine-cystatin compared to creatinine) was associated with increasing elevation of biomarkers (including N-terminal pro-B-type natriuretic peptide and troponin) and worsening Kansas City Cardiomyopathy Questionnaire clinical summary score. The reason why the equations diverged with increasing severity of heart failure was that creatinine did not rise as steeply as cystatin C. CONCLUSION: The CKD-EPI creatinine-only equation may overestimate GFR in sicker patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT01035255.

Stroke in patients with heart failure and reduced or preserved ejection fraction.

AIMS: Stroke is an important problem in patients with heart failure (HF), but the intersection between the two conditions is poorly studied across the range of ejection fraction. The prevalence of history of stroke and related outcomes were investigated in patients with HF. METHODS AND RESULTS: Individual patient meta-analysis of seven clinical trials enrolling patients with HF with reduced (HFrEF) and preserved ejection fraction (HFpEF). Of the 20 159 patients with HFrEF, 1683 (8.3%) had a history of stroke, and of the 13 252 patients with HFpEF, 1287 (9.7%) had a history of stroke. Regardless of ejection fraction, patients with a history of stroke had more vascular comorbidity and worse HF. Among those with HFrEF, the incidence of the composite of cardiovascular death, HF hospitalization, stroke, or myocardial infarction was 18.23 (16.81-19.77) per 100 person-years in those with prior stroke vs. 13.12 (12.77-13.48) in those without [hazard ratio 1.37 (1.26-1.49), P < 0.001]. The corresponding rates in patients with HFpEF were 14.16 (12.96-15.48) and 9.37 (9.06-9.70) [hazard ratio 1.49 (1.36-1.64), P < 0.001]. Each component of the composite was more frequent in patients with stroke history, and the risk of future stroke was doubled in patients with prior stroke. Among patients with prior stroke, 30% with concomitant atrial fibrillation were not anticoagulated, and 29% with arterial disease were not taking statins; 17% with HFrEF and 38% with HFpEF had uncontrolled systolic blood pressure (≥140 mmHg). CONCLUSION: Heart failure patients with a history of stroke are at high risk of subsequent cardiovascular events, and targeting underutilization of guideline-recommended treatments might be a way to improve outcomes in this high-risk population.

Critical Reanalysis of the Mechanisms Underlying the Cardiorenal Benefits of SGLT2 Inhibitors and Reaffirmation of the Nutrient Deprivation Signaling/Autophagy Hypothesis.

SGLT2 (sodium-glucose cotransporter 2) inhibitors produce a distinctive pattern of benefits on the evolution and progression of cardiomyopathy and nephropathy, which is characterized by a reduction in oxidative and endoplasmic reticulum stress, restoration of mitochondrial health and enhanced mitochondrial biogenesis, a decrease in proinflammatory and profibrotic pathways, and preservation of cellular and organ integrity and viability. A substantial body of evidence indicates that this characteristic pattern of responses can be explained by the action of SGLT2 inhibitors to promote cellular housekeeping by enhancing autophagic flux, an effect that may be related to the action of these drugs to produce simultaneous upregulation of nutrient deprivation signaling and downregulation of nutrient surplus signaling, as manifested by an increase in the expression and activity of AMPK (adenosine monophosphate-activated protein kinase), SIRT1 (sirtuin 1), SIRT3 (sirtuin 3), SIRT6 (sirtuin 6), and PGC1-α (peroxisome proliferator-activated receptor γ coactivator 1-α) and decreased activation of mTOR (mammalian target of rapamycin). The distinctive pattern of cardioprotective and renoprotective effects of SGLT2 inhibitors is abolished by specific inhibition or knockdown of autophagy, AMPK, and sirtuins. In the clinical setting, the pattern of differentially increased proteins identified in proteomics analyses of blood collected in randomized trials is consistent with these findings. Clinical studies have also shown that SGLT2 inhibitors promote gluconeogenesis, ketogenesis, and erythrocytosis and reduce uricemia, the hallmarks of nutrient deprivation signaling and the principal statistical mediators of the ability of SGLT2 inhibitors to reduce the risk of heart failure and serious renal events. The action of SGLT2 inhibitors to augment autophagic flux is seen in isolated cells and tissues that do not express SGLT2 and are not exposed to changes in environmental glucose or ketones and may be related to an ability of these drugs to bind directly to sirtuins or mTOR. Changes in renal or cardiovascular physiology or metabolism cannot explain the benefits of SGLT2 inhibitors either experimentally or clinically. The direct molecular effects of SGLT2 inhibitors in isolated cells are consistent with the concept that SGLT2 acts as a nutrient surplus sensor, and thus, its inhibition causes enhanced nutrient deprivation signaling and its attendant cytoprotective effects, which can be abolished by specific inhibition or knockdown of AMPK, sirtuins, and autophagic flux.

Empagliflozin for Heart Failure With Preserved Left Ventricular Ejection Fraction With and Without Diabetes.

BACKGROUND: Empagliflozin improves outcomes in patients with heart failure with a preserved ejection fraction, but whether the effects are consistent in patients with and without diabetes remains to be elucidated. METHODS: Patients with class II through IV heart failure and a left ventricular ejection fraction >40% were randomized to receive empagliflozin 10 mg or placebo in addition to usual therapy. We undertook a prespecified analysis comparing the effects of empagliflozin versus placebo in patients with and without diabetes. RESULTS: Of the 5988 patients enrolled, 2938 (49%) had diabetes. The risk of the primary outcome (first hospitalization for heart failure or cardiovascular death), total hospitalizations for heart failure, and estimated glomerular filtration rate decline was higher in patients with diabetes. Empagliflozin reduced the rate of the primary outcome irrespective of diabetes status (hazard ratio, 0.79 [95% CI, 0.67, 0.94] for patients with diabetes versus hazard ratio, 0.78 [95% CI, 0.64, 0.95] in patients without diabetes; Pinteraction=0.92). The effect of empagliflozin to reduce total hospitalizations for heart failure was also consistent in patients with and without diabetes. The effect of empagliflozin to attenuate estimated glomerular filtration rate decline during double-blind treatment was also present in patients with and without diabetes, although more pronounced in patients with diabetes (1.77 in diabetes versus 0.98 mL/min/1.73m2 in patients without diabetes; Pinteraction=0.01). Across these 3 end points, the effect of empagliflozin did not differ in patients with prediabetes or normoglycemia (33% and 18% of the patient population, respectively). When investigated as a continuous variable, baseline hemoglobin A1c did not modify the effects on the primary outcome (Pinteraction=0.26). There was no increased risk of hypoglycemic events in either subgroup as compared with placebo. CONCLUSIONS: In patients with heart failure and a preserved ejection fraction enrolled in the EMPEROR-Preserved (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Preserved Ejection Fraction), empagliflozin significantly reduced the risk of heart failure outcomes irrespective of diabetes status at baseline. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03057951.

Empagliflozin, Health Status, and Quality of Life in Patients With Heart Failure and Preserved Ejection Fraction: The EMPEROR-Preserved Trial.

BACKGROUND: Patients with heart failure with preserved ejection fraction have significant impairment in health-related quality of life. In the EMPEROR-Preserved trial (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Preserved Ejection Fraction), we evaluated the efficacy of empagliflozin on health-related quality of life in patients with heart failure with preserved ejection fraction and whether the clinical benefit observed with empagliflozin varies according to baseline health status. METHODS: Health-related quality of life was measured with the Kansas City Cardiomyopathy Questionnaire (KCCQ) at baseline and 12, 32, and 52 weeks. Patients were divided by baseline KCCQ Clinical Summary Score (CSS) tertiles, and the effect of empagliflozin on outcomes was examined. The effect of empagliflozin on KCCQ-CSS, Total Symptom Score, and Overall Summary Score was evaluated. Responder analyses were performed to compare the odds of improvement and deterioration in KCCQ related to treatment with empagliflozin. RESULTS: The effect of empagliflozin on reducing the risk of time to cardiovascular death or heart failure hospitalization was consistent across baseline KCCQ-CSS tertiles (hazard ratio, 0.83 [95% CI, 0.69-1.00], 0.70 [95% CI, 0.55-0.88], and 0.82 [95% CI, 0.62-1.08] for scores <62.5, 62.5-83.3, and ≥83.3, respectively; P trend=0.77). Similar results were seen for total heart failure hospitalizations. Patients treated with empagliflozin had significant improvement in KCCQ-CSS versus placebo (+1.03, +1.24, and +1.50 at 12, 32, and 52 weeks, respectively; P<0.01); similar results were seen for Total Symptom Score and Overall Summary Score. At 12 weeks, patients on empagliflozin had higher odds of improvement ≥5 points (odds ratio, 1.23 [95% CI, 1.10-1.37]), ≥10 points (odds ratio, 1.15 [95% CI, 1.03-1.27]), and ≥15 points (odds ratio, 1.13 [95% CI, 1.02-1.26]) and lower odds of deterioration ≥5 points in KCCQ-CSS (odds ratio, 0.85 [95% CI, 0.75-0.97]). A similar pattern was seen at 32 and 52 weeks, and results were consistent for Total Symptom Score and Overall Summary Score. CONCLUSIONS: In patients with heart failure with preserved ejection fraction, empagliflozin reduced the risk for major heart failure outcomes across the range of baseline KCCQ scores. Empagliflozin improved health-related quality of life, an effect that appeared early and was sustained for at least 1 year. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03057951.