Critical re-evaluation of the identification of iron deficiency states and effective iron repletion strategies in patients with chronic heart failure.

According to current guidelines, iron deficiency is defined by a serum ferritin level <100 ng/ml or a transferrin saturation (TSAT) <20% if the serum ferritin level is 100-299 µg/L. These criteria were developed to encourage the use of intravenous iron as an adjunct to erythropoiesis-stimulating agents in the treatment of renal anaemia. However, in patients with heart failure, these criteria are not supported by any pathophysiological or clinical evidence that they identify an absolute or functional iron deficiency state. A low baseline TSAT-but not serum ferritin level-appears to be a reliable indicator of the effect of intravenous iron to reduce major heart failure events. In randomized controlled trials, intravenous iron decreased the risk of cardiovascular death or total heart failure hospitalization in patients with a TSAT <20% (risk ratio 0.67 [0.49-0.92]) but not in patients with a TSAT ≥20% (risk ratio 0.99 [0.74-1.30]), with the magnitude of the risk reduction being proportional to the severity of hypoferraemia. Patients who were enrolled in clinical trials solely because they had a serum ferritin level <100 µg/L showed no significant benefit on heart failure outcomes, and it is noteworthy that serum ferritin levels of 20-300 µg/L lie entirely within the range of normal values for healthy adults. Current guidelines reflect the eligibility criteria of clinical trials, which inadvertently adopted unvalidated criteria to define iron deficiency. Reliance on these guidelines would lead to the treatment of many patients who are not iron deficient (serum ferritin level <100 µg/L but normal TSAT) and ignores the possibility of iron deficiency in patients with a low TSAT but with serum ferritin level of >300 µg/L. Importantly, analyses of benefit based on trial eligibility-driven guidelines substantially underestimate the magnitude of heart-failure-event risk reduction with intravenous iron in patients who are truly iron deficient. Based on all available data, we recommend a new mechanism-based and trial-tested approach that reflects the totality of evidence more faithfully than the historical process adopted by clinical investigators and by the guidelines. Until additional evidence is forthcoming, an iron deficiency state in patients with heart failure should be defined by a TSAT <20% (as long as the serum ferritin level is <400 µg/L), and furthermore, the use of a serum ferritin level <100 µg/L alone as a diagnostic criterion should be discarded.

Iron homeostasis, recycling and vulnerability in the stressed kidney: A neglected dimension of iron-deficient heart failure.

The available evidence suggests that the kidney may contribute importantly to the development of an iron deficiency state in patients with heart failure and may be injured by therapeutic efforts to achieve iron repletion. The exceptional workload of the proximal renal tubule requires substantial quantities of iron for ATP synthesis, which it derives from Fe3+ bound to transferrin in the bloodstream. Following ferrireduction, Fe2+ is conveyed by divalent transporters (e.g. DMT1) out of the endosome of the proximal renal tubule, and highly reactive Fe2+ can be directed to the mitochondria, sequestered safely in a ferritin nanocage or exported through the actions of hepcidin-inhibitable ferroportin. The actions of ferroportin, together with transferrin endocytosis and DMT1-mediated transport, play a key role in the recycling of iron from the tubular fluid into the bloodstream and preventing the loss of filtered iron in the urine. Activation of endogenous neurohormonal systems and proinflammatory signalling in heart failure decrease megalin-mediated uptake and DMT1 expression, and increase hepcidin-mediated suppression of ferroportin, promoting the loss of iron in the urine and contributing to the development of an iron deficiency state. Furthermore, the failure of ferroportin-mediated efflux at the basolateral membrane heightens the susceptibility of the renal tubules to cytosolic excesses of Fe2+, causing lipid peroxidation and synchronized cell death (ferroptosis) through the iron-dependent free radical theft of electrons from lipids in the cell membrane. Ferroptosis is a central mechanism to most disorders that can cause acute and chronic kidney disease. Short-term bolus administration of intravenous iron can cause oxidative stress and is accompanied by markers of renal injury. Experimentally, long-term maintenance of an iron-replete state is accompanied by accelerated loss of nephrons, oxidative stress, inflammation and fibrosis. Intravenous iron therapy increases glomerular filtration rate rapidly in patients with heart failure (perhaps because of a haemodynamic effect) but not in patients with chronic kidney disease, and the effects of intravenous iron on the progression of renal dysfunction in the long-term trials - AFFIRM-AHF, IRONMAN and HEART-FID - have not yet been reported. Given the potential role of dysregulated renal iron homeostasis in the pathogenesis of iron deficiency and the known vulnerability of the kidney to intravenous iron, the appropriate level of iron repletion with respect to the risk of acute and chronic kidney injury in patients with heart failure requires further study.

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.

Hyperuricemia and Gout Reduction by SGLT2 Inhibitors in Diabetes and Heart Failure: JACC Review Topic of the Week.

Gout is characterized by increased production of purines (through the pentose phosphate pathway), which is coupled with reduced renal or intestinal excretion of urate. Concurrent upregulation of nutrient surplus signaling (mammalian target of rapamycin and hypoxia-inducible factor-1a) and downregulation of nutrient deprivation signaling (sirtuin-1 and adenosine monophosphate-activated protein kinase) redirects glucose toward anabolic pathways (rather than adenosine triphosphate production), thus promoting heightened oxidative stress and cardiomyocyte and proximal tubular dysfunction, leading to cardiomyopathy and kidney disease. Hyperuricemia is a marker (rather than a driver) of these cellular stresses. By inducing a state of starvation mimicry in a state of nutrient surplus, sodium-glucose cotransporter-2 inhibitors decrease flux through the pentose phosphate pathway (thereby attenuating purine and urate synthesis) while promoting renal urate excretion. These convergent actions exert a meaningful effect to lower serum uric acid by ≈0.6 to 1.5 mg/dL and to reduce the risk of gout by 30% to 50% in large-scale clinical trials.

Growth differentiation factor-15 and the effect of empagliflozin in heart failure: Findings from the EMPEROR program.

AIMS: Growth differentiation factor-15 (GDF-15) is upregulated in part in response to cardiomyocyte stretch and stress, and it exerts a protective role that is mediated by its action to suppress signalling through insulin-like growth factor (IGF) and enhance signalling through adenosine monophosphate-activated protein kinase (AMPK). Sodium-glucose cotransporter 2 (SGLT2) inhibitors improve outcomes in heart failure, which has been experimentally linked to AMPK. This study aimed at evaluating the associations of GDF-15 with baseline characteristics, the prognostic significance of GDF-15, and the effect of empagliflozin on GDF-15 in patients with heart failure with a reduced and preserved ejection fraction. METHODS AND RESULTS: Growth differentiation factor-15 was determined in serum samples from the EMPEROR-Reduced and EMPEROR-Preserved trials. Cox regression and mixed models for repeated measures were used to study the association with outcomes and the effect of empagliflozin on GDF-15, respectively. We studied 1124 patients (560 placebo and 564 empagliflozin) with median GDF-15 levels at baseline of 2442 (interquartile range 1603-3780) pg/ml. Patients with higher GDF-15 levels were typically older men with more severe symptoms, higher N-terminal pro-B-type natriuretic peptide levels, worse kidney function and who were prescribed metformin. Baseline levels of GDF-15 were well correlated with levels of IGF-binding protein 7 (rho = 0.64). Higher levels of GDF-15 were independently associated with an increased risk of cardiovascular death, heart failure hospitalizations, and worse kidney outcomes. When considered as a continuous variable, for each doubling in GDF-15, the adjusted hazard ratio for cardiovascular death or heart failure hospitalization was 1.40 (95% confidence interval 1.15-1.71; p < 0.001). The relative effect of empagliflozin on cardiovascular death and hospitalization for heart failure was most pronounced in patients with higher baseline levels of GDF-15 (interaction p-trend = 0.031). At week 52, when compared with placebo, empagliflozin increased GDF-15 by an additional 8% (p = 0.020), an effect that was primarily seen in patients not receiving metformin, a known AMPK activator. CONCLUSIONS: Growth differentiation factor-15 is a marker of worse heart failure severity, is an independent predictor of major heart failure outcomes and may be associated with more pronounced benefits of empagliflozin. GDF-15 is increased among metformin users, and empagliflozin was associated with an increase in GDF-15 levels, primarily in patients not receiving metformin.

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.

Efficacy of empagliflozin in heart failure with preserved ejection fraction according to frailty status in EMPEROR-Preserved.

BACKGROUND: Frailty is a severe, common co-morbidity associated with heart failure (HF) with preserved ejection fraction (HFpEF). The impact of frailty on HFpEF outcomes may affect treatment choices in HFpEF. The impact of frailty on HFpEF patients and any impact on the clinical benefits of sodium glucose co-transporter 2 (SGLT2) inhibition in HFpEF have been described in only a limited number of trials. Whether the SGLT2 inhibitor empagliflozin would improve or worsen frailty status when given to HFpEF patients is also not known. The aims of this study were, therefore, to evaluate, in HFpEF patients enrolled in the EMPEROR-Preserved trial (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Preserved Ejection Fraction), the impact of frailty on clinical outcomes, and on the effects of empagliflozin, as well as the effect of empagliflozin on frailty status during treatment period. METHODS: We calculated a cumulative deficit-derived frailty index (FI) using 44 variables including clinical, laboratory and quality of life parameters recorded in EMPEROR-Preserved. Patients were classified into four groups: non-frail (FI < 0.21), mild frailty (0.21 to <0.30), moderate frailty (0.30 to <0.40) and severe frailty (≥0.40). Clinical outcomes and health-related quality of life were evaluated according to baseline FI along with the effect of empagliflozin on chronological changes in FI (at 12, 32 and 52 weeks). RESULTS: The patient distribution was 1514 (25.3%), 2100 (35.1%), 1501 (25.1%) and 873 (14.6%) in non-frail, mild frailty, moderate frailty and severe frailty, respectively. Severe frailty patients tended to be female and have low Kansas City Cardiomyopathy Questionnaire (KCCQ) scores, more co-morbidities and more polypharmacy. Incidence rates of the primary outcome of cardiovascular death or HF hospitalization increased as frailty worsened (hazard ratio [HR] of each FI category compared with the non-frail group: 1.10 [95% confidence interval, CI, 0.89-1.35], 2.00 [1.63-2.47] and 2.61 [2.08-3.27] in the mild frailty, moderate frailty and severe frailty groups, respectively; P trend < 0.001). Compared with placebo, empagliflozin reduced the risk for the primary outcome across the four FI categories, HR: 0.59 [95% CI 0.42-0.83], 0.79 [0.61-1.01], 0.77 [0.61-0.96] and 0.90 [0.69-1.16] in non-frail to severe frailty categories, respectively (P value for trend = 0.097). Empagliflozin also improved other clinical outcomes and KCCQ score across frailty categories. Compared with placebo, empagliflozin-treated patients had a higher likelihood of being in a lower FI category at Weeks 12, 32 and 52 (P < 0.05), odds ratio: 1.12 [95% CI 1.01-1.24] at Week 12, 1.21 [1.09-1.34] at Week 32 and 1.20 [1.09-1.33] at Week 52. CONCLUSIONS: Empagliflozin improved key efficacy outcomes with a possible diminution of effect in very frail patients. Empagliflozin also improved frailty status during follow-up.

Qiliqiangxin: A multifaceted holistic treatment for heart failure or a pharmacological probe for the identification of cardioprotective mechanisms?

The active ingredients in many traditional Chinese medicines are isoprene oligomers with a diterpenoid or triterpenoid structure, which exert cardiovascular effects by signalling through nutrient surplus and nutrient deprivation pathways. Qiliqiangxin (QLQX) is a commercial formulation of 11 different plant ingredients, whose active compounds include astragaloside IV, tanshione IIA, ginsenosides (Rb1, Rg1 and Re) and periplocymarin. In the QUEST trial, QLQX reduced the combined risk of cardiovascular death or heart failure hospitalization (hazard ratio 0.78, 95% confidence interval 0.68-0.90), based on 859 events in 3119 patients over a median of 18.2 months; the benefits were seen in patients taking foundational drugs except for sodium-glucose cotransporter 2 (SGLT2) inhibitors. Numerous experimental studies of QLQX in diverse cardiac injuries have yielded highly consistent findings. In marked abrupt cardiac injury, QLQX mitigated cardiac injury by upregulating nutrient surplus signalling through the PI3K/Akt/mTOR/HIF-1α/NRF2 pathway; the benefits of QLQX were abrogated by suppression of PI3K, Akt, mTOR, HIF-1α or NRF2. In contrast, in prolonged measured cardiac stress (as in chronic heart failure), QLQX ameliorated oxidative stress, maladaptive hypertrophy, cardiomyocyte apoptosis, and proinflammatory and profibrotic pathways, while enhancing mitochondrial health and promoting glucose and fatty acid oxidation and ATP production. These effects are achieved by an action of QLQX to upregulate nutrient deprivation signalling through SIRT1/AMPK/PGC-1α and enhanced autophagic flux. In particular, QLQX appears to enhance the interaction of PGC-1α with PPARα, possibly by direct binding to RXRα; silencing of SIRT1, PGC-1α and RXRα abrogated the favourable effects of QLQX in the heart. Since PGC-1α/RXRα is also a downstream effector of Akt/mTOR signalling, the actions of QLQX on PGC-1α/RXRα may explain its favourable effects in both acute and chronic stress. Intriguingly, the individual ingredients in QLQX - astragaloside IV, ginsenosides, and tanshione IIA - share QLQX's effects on PGC-1α/RXRα/PPARα signalling. QXQL also contains periplocymarin, a cardiac glycoside that inhibits Na+ -K+ -ATPase. Taken collectively, these observations support a conceptual framework for understanding the mechanism of action for QLQX in heart failure. The high likelihood of overlap in the mechanism of action of QLQX and SGLT2 inhibitors requires additional experimental studies and clinical trials.

Health and Economic Evaluation of Sacubitril-Valsartan for Heart Failure Management.

Importance: The US Food and Drug Administration expanded labeling of sacubitril-valsartan from the treatment of patients with chronic heart failure (HF) with reduced ejection fraction (EF) to all patients with HF, noting the greatest benefits in those with below-normal EF. However, the upper bound of below normal is not clearly defined, and value determinations across a broader EF range are unknown. Objective: To estimate the cost-effectiveness of sacubitril-valsartan vs renin-angiotensin system inhibitors (RASis) across various upper-level cutoffs of EF. Design, Setting, and Participants: This economic evaluation included participant-level data from the PARADIGM-HF (Prospective Comparison of ARNI With ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure) and the PARAGON-HF (Prospective Comparison of ARNi with ARB Global Outcomes in HF With Preserved Ejection Fraction) trials. PARADIGM-HF was conducted between 2009 and 2014, PARAGON-HF was conducted between 2014 and 2019, and this analysis was conducted between 2021 and 2023. Main Outcomes and Measures: A 5-state Markov model used risk reductions for all-cause mortality and HF hospitalization from PARADIGM-HF and PARAGON-HF. Quality-of-life differences were estimated from EuroQol-5D scores. Hospitalization and medication costs were obtained from published national sources; the wholesale acquisition cost of sacubitril-valsartan was $7092 per year. Risk estimates and treatment effects were generated in consecutive 5% EF increments up to 60% and applied to an EF distribution of US patients with HF from the Get With the Guidelines-Heart Failure registry. The base case included a lifetime horizon from a health care sector perspective. Incremental cost-effectiveness ratios (ICERs) were estimated at EFs of 60% or less (base case) and at various upper-level EF cutoffs. Results: Among 13 264 total patients whose data were analyzed, for those with EFs of 60% or less, sacubitril-valsartan was projected to add 0.53 quality-adjusted life-years (QALYs) at an incremental lifetime cost of $40 892 compared with RASi, yielding an ICER of $76 852 per QALY. In a probabilistic sensitivity analysis, 95% of the values of the ICER occurred between $71 516 and $82 970 per QALY. Among patients with chronic HF and an EF of 60% or less, treatment with sacubitril-valsartan vs RASis would be at least of economic intermediate value (ICER <$180 000 per QALY) at a sacubitril-valsartan cost of $10 242 or less per year, of high economic value (ICER <$60 000 per QALY) at a cost of $3673 or less per year, and cost-saving at a cost of $338 or less per year. The ICERs were $67 331 per QALY, $59 614 per QALY, and $56 786 per QALY at EFs of 55% or less, 50% or less, and 45% or less, respectively. Treatment with sacubitril-valsartan in only those with EFs of 45% or greater (up to ≤60%) yielded an ICER of $127 172 per QALY gained; treatment was more cost-effective in those at the lower end of this range (ICER of $100 388 per QALY gained for those with EFs of 45%-55%; ICER of $84 291 per QALY gained for those with EFs of 45%-50%). Conclusions and Relevance: Cost-effectiveness modeling provided an ICER for treatment with sacubitril-valsartan vs RASis consistent with high economic value for patients with reduced and mildly reduced EFs (≤50%) and at least intermediate value at the current undiscounted wholesale acquisition cost price at an EF of 60% or less. Treatment was more cost-effective at lower EF ranges. These findings may have implications for coverage decisions and value assessments in contemporary clinical practice guidelines.

Short-Term Changes in Peak VO2 After Initiation of Dapagliflozin in Heart Failure Across Iron Status.

BACKGROUND: Some studies have indicated that sodium-glucose cotransporter-2 (SGLT2) inhibitors promote an increase in cell iron use. OBJECTIVES: The aim of this study was to examine, in patients with stable heart failure with reduced left ventricular ejection fraction (HFrEF), the effect of dapagliflozin on ferrokinetic parameters and whether short-term changes in peak oxygen consumption (Vo2) after dapagliflozin treatment are influenced by baseline and serial ferrokinetic status. METHODS: This was an exploratory analysis of a randomized, double-blind clinical trial that evaluated the effect of dapagliflozin vs placebo on peak Vo2 in patients with HFrEF (NCT04197635) and included 76 of the 90 patients initially enrolled in the trial. Changes in peak Vo2 at 1 and 3 months were explored according to baseline and longitudinal ferrokinetic parameters (natural logarithm [ln] ferritin, transferrin saturation index [TSAT], soluble transferrin receptor, and hepcidin). Linear mixed-effect regression was used for the analyses. RESULTS: Compared with placebo, dapagliflozin led to a significant decrease in 3-month ln ferritin (P = 0.040) and an increase in 1-month ln soluble transferrin receptor (P = 0.023). Between-treatment comparisons revealed a stepwise increase in peak Vo2 in the dapagliflozin group at 1 and 3 months, which was especially apparent at lower baseline values of TSAT and ferritin (P < 0.05). Lower time-varying values of TSAT (1 and 3 months) also identified patients with greater improvements in peak Vo2. CONCLUSIONS: In patients with stable HFrEF, treatment with dapagliflozin resulted in short-term increases in peak Vo2, which were most marked in patients with surrogates of greater iron deficiency at baseline and during treatment. (Short-Term Effects of Dapagliflozin on Peak Vo2 in HFrEF [DAPA-VO2]; NCT04197635).

Erythropoietic response after intravenous iron in patients with heart failure and reduced ejection fraction with and without background treatment with sodium-glucose cotransporter 2 inhibitors.

AIMS: Intravenous (IV) iron increases haemoglobin/haematocrit and improves outcomes in patients with heart failure with reduced ejection fraction (HFrEF) and iron deficiency. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) also increase haemoglobin/haematocrit and improve outcomes in heart failure by mechanisms linked to nutrient deprivation signalling and reduction of inflammation and oxidative stress. The effect of IV iron among patients using SGLT2i has not yet been studied. The aim of this study was to evaluate the changes in haemoglobin, haematocrit, and iron biomarkers in HFrEF patients treated with IV iron with and without background SGLT2i treatment. Secondary outcomes included changes in natriuretic peptides, kidney function and heart failure-associated outcomes. METHODS AND RESULTS: Retrospective, single-centre analysis of HFrEF patients with iron deficiency treated with IV iron using (n = 60) and not using (n = 60) SGLT2i, matched for age and sex. Mean age was 73 ± 12 years, 48% were men, with more than 65% of patients having chronic kidney disease and anaemia. After adjustment for all baseline differences, SGLT2i users experienced a greater increase in haemoglobin and haematocrit compared to SGLT2i non-users: haemoglobin +0.57 g/dl (95% confidence interval [CI] 0.04-1.10, p = 0.036) and haematocrit +1.64% (95% CI 0.18-3.11, p = 0.029). No significant differences were noted for iron biomarkers or any of the secondary outcomes. CONCLUSION: Combined treatment with IV iron and background SGLT2i was associated with a greater increase in haemoglobin and haematocrit than IV iron without background SGLT2i. These results suggest that in HFrEF patients treated with IV iron, SGLT2i may increase the erythropoietic response. Further studies are needed to ascertain the potential benefit or harm of combining these two treatments in heart failure patients.

Vascular Disease Burden, Outcomes and Benefits with Empagliflozin in Heart Failure: Insights From the EMPEROR-Reduced Trial.

BACKGROUND: The presence of ischemic heart disease impacts prognosis in patients affected by heart failure and reduced ejection fraction (HFrEF). It is not well known how the extent of vascular disease impacts prognoses and responses to therapy in this setting. METHODS: In this post hoc analysis of the EMPEROR-Reduced trial, outcomes and the effects of empagliflozin, were assessed in study participants according to the extent (none vs mono1 vs poly [≥ 2] vascular bed) of vascular disease. Vascular disease was defined as investigator-reported coronary artery disease (CAD), peripheral artery disease (PAD) and cerebrovascular disease at baseline. Cox proportional-hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Incidence rates are presented per 100 person-years (py) of follow-up. RESULTS: Of the 3730 study participants enrolled, 1324 (35.5%) had no vascular disease, 1879 (50.4%) had monovascular disease, and 527 (14.1%) had polyvascular disease. Participants with polyvascular disease tended to be older and male and to have had histories of hypertension, diabetes and smoking. In the placebo arm, a significantly higher risk for cardiovascular death existed in those with polyvascular disease (HR 1.57, 95% CI1.02, 2.44, compared to those with no vascular disease). In adjusted analysis, the benefit of empagliflozin in cardiovascular death or hospitalization due to HF, HF hospitalization, cardiovascular death, renal composite endpoint, estimated glomerular filtration slope changes, and health status scores were seen across the 3 groups (interaction P > 0.05 for all) but were attenuated in those with polyvascular disease. Adverse events were higher in those with polyvascular disease, but no major differences were noted between empagliflozin or placebo assignment in the 3 groups. CONCLUSION: In patients with HFrEF, the extent of vascular disease is associated with the risk for adverse cardiovascular outcomes. Empagliflozin offers cardiovascular and renal benefits in HFrEF across the extent of vascular disease, but this benefit is attenuated in those with polyvascular disease.

Foetal recapitulation of nutrient surplus signalling by O-GlcNAcylation and the failing heart.

The development of the foetal heart is driven by increased glucose uptake and activation of mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1α (HIF-1α), which drives glycolysis. In contrast, the healthy adult heart is governed by sirtuin-1 (SIRT1) and adenosine monophosphate-activated protein kinase (AMPK), which promote fatty-acid oxidation and the substantial mitochondrial ATP production required for survival in a high-workload normoxic environment. During cardiac injury, the heart recapitulates the foetal signalling programme, which (although adaptive in the short term) is highly deleterious if sustained for long periods of time. Prolonged increases in glucose uptake in cardiomyocytes under stress leads to increased flux through the hexosamine biosynthesis pathway; its endproduct - uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) - functions as a critical nutrient surplus sensor. UDP-GlcNAc drives the post-translational protein modification known as O-GlcNAcylation, which rapidly and reversibly modifies thousands of intracellular proteins. 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 by only two enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), which adds or removes GlcNAc (N-acetylglucosamine), respectively, from target proteins. Recapitulation of foetal programming in heart failure (regardless of diabetes) is accompanied by marked increases in O-GlcNAcylation, both experimentally and clinically. Heightened O-GlcNAcylation in the heart leads to impaired calcium kinetics and contractile derangements, arrhythmias related to activation of voltage-gated sodium channels and Ca2+ /calmodulin-dependent protein kinase II, mitochondrial dysfunction, and maladaptive hypertrophy, microvascular dysfunction, fibrosis and cardiomyopathy. These deleterious effects can be prevented by suppression of O-GlcNAcylation, which can be achieved experimentally by upregulation of AMPK and SIRT1 or by pharmacological inhibition of OGT or stimulation of OGA. The effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors on the heart are accompanied by reduced O-GlcNAcylation, and their cytoprotective effects are reportedly abrogated if their action to suppress O-GlcNAcylation is blocked. Such an action may represent one of the many mechanisms by which enhanced AMPK and SIRT1 signalling following SGLT2 inhibition leads to cardiovascular benefits. These observations, taken collectively, suggest that UDP-GlcNAc functions as a critical nutrient surplus sensor (which acting in concert with mTOR and HIF-1α) can promote the development of cardiomyopathy.

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.

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.

Incremental prognostic value of biomarkers in PARADIGM-HF.

AIMS: It is uncertain how much candidate biomarkers improve risk prediction when added to comprehensive models including routinely collected clinical and laboratory variables in heart failure. METHODS AND RESULTS: Aldosterone, cystatin C, high-sensitivity troponin T (hs-TnT), galectin-3, growth differentiation factor-15 (GDF-15), kidney injury molecule-1, matrix metalloproteinase-2 and -9, soluble suppression of tumourigenicity-2, tissue inhibitor of metalloproteinase-1 (TIMP-1) and urinary albumin to creatinine ratio were measured in 1559 of PARADIGM-HF participants. We tested whether these biomarkers, individually or collectively, improved the performance of the PREDICT-HF prognostic model, which includes clinical, routine laboratory, and natriuretic peptide data, for the primary endpoint and cardiovascular and all-cause mortality. The mean age of participants was 67.3 ± 9.9 years, 1254 (80.4%) were men and 1103 (71%) were in New York Heart Association class II. During a mean follow-up of 30.7 months, 300 patients experienced the primary outcome and 197 died. Added individually, only four biomarkers were independently associated with all outcomes: hs-TnT, GDF-15, cystatin C and TIMP-1. When all biomarkers were added simultaneously to the PREDICT-HF models, only hs-TnT remained an independent predictor of all three endpoints. GDF-15 also remained predictive of the primary endpoint; TIMP-1 was the only other predictor of both cardiovascular and all-cause mortality. Individually or in combination, these biomarkers did not lead to significant improvements in discrimination or reclassification. CONCLUSIONS: None of the biomarkers studied individually or collectively led to a meaningful improvement in the prediction of outcomes over what is provided by clinical, routine laboratory, and natriuretic peptide variables.

Clinical and Prognostic Relevance of Cardiac Wasting in Patients With Advanced Cancer.

BACKGROUND: Body wasting in patients with cancer can affect the heart. OBJECTIVES: The frequency, extent, and clinical and prognostic importance of cardiac wasting in cancer patients is unknown. METHODS: This study prospectively enrolled 300 patients with mostly advanced, active cancer but without significant cardiovascular disease or infection. These patients were compared with 60 healthy control subjects and 60 patients with chronic heart failure (ejection fraction <40%) of similar age and sex distribution. RESULTS: Cancer patients presented with lower left ventricular (LV) mass than healthy control subjects or heart failure patients (assessed by transthoracic echocardiography: 177 ± 47 g vs 203 ± 64 g vs 300 ± 71 g, respectively; P < 0.001). LV mass was lowest in cancer patients with cachexia (153 ± 42 g; P < 0.001). Importantly, the presence of low LV mass was independent of previous cardiotoxic anticancer therapy. In 90 cancer patients with a second echocardiogram after 122 ± 71 days, LV mass had declined by 9.3% ± 1.4% (P < 0.001). In cancer patients with cardiac wasting during follow-up, stroke volume decreased (P < 0.001) and resting heart rate increased over time (P = 0.001). During follow-up of on average 16 months, 149 patients died (1-year all-cause mortality 43%; 95% CI: 37%-49%). LV mass and LV mass adjusted for height squared were independent prognostic markers (both P < 0.05). Adjustment of LV mass for body surface area masked the observed survival impact. LV mass below the prognostically relevant cutpoints in cancer was associated with reduced overall functional status and lower physical performance. CONCLUSIONS: Low LV mass is associated with poor functional status and increased all-cause mortality in cancer. These findings provide clinical evidence of cardiac wasting-associated cardiomyopathy in cancer.

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.

Characteristics and outcomes of patients with a history of cancer recruited to heart failure trials.

AIMS: Heart failure (HF) therapy trials usually exclude cancer patients. We examined the association between cancer history and outcomes in trial participants with HF and reduced (HFrEF) or preserved ejection fraction (HFpEF). METHODS AND RESULTS: We combined PARADIGM-HF and ATMOSPHERE, which enrolled HFrEF patients (n = 15 415) and we pooled HFpEF patients (ejection fraction ≥45%) enrolled in PARAGON-HF and CHARM-Preserved (n = 7363). The associations between cancer history, cardiovascular (CV) death, HF hospitalization, non-CV and all-cause death in these trials were examined. Incident cancer diagnoses during these trials were also measured. There were 658 (4.3%) and 624 (8.5%) patients with a cancer history in the HFrEF and HFpEF trials, respectively. HFrEF patients with a cancer history had a higher risk of HF hospitalization (adjusted hazard ratio [HR] 1.28; 95% confidence interval [CI] 1.07-1.52, p = 0.007) and non-CV death (adjusted HR 1.57; 95% CI 1.16-2.12, p = 0.003) than those without. The risks of other outcomes were similar. There were no differences in the risk of any outcome in HFpEF patients with and without a cancer history. Adjusting for age and sex, the incidence of new cancer in the HFrEF and HFpEF trials was 1.09 (95% CI 0.83-1.36) and 1.07 (95% CI 0.81-1.32) per 100 person-years, respectively. CONCLUSIONS: Although participants in HFrEF trials with a cancer history had higher risks of HF hospitalization and non-CV death than those without, the risks of CV and all-cause death were similar. Outcomes in HFpEF patients with and without a cancer history were similar. Incident cancer diagnoses were similar in HFrEF and HFpEF trials.