bims-hafaim 2024-04-14 papers

Issue of 2024–04–14
five papers selected by
Kyle McCommis, Saint Louis University

Front Cardiovasc Med. 2024 ;11 1375400

Molecular mechanisms of metabolic dysregulation in diabetic cardiomyopathy.

Yue Zeng, Yilang Li, Wenyue Jiang, Ning Hou.

Diabetic cardiomyopathy (DCM), one of the most serious complications of diabetes mellitus, has become recognized as a cardiometabolic disease. In normoxic conditions, the majority of the ATP production (>95%) required for heart beating comes from mitochondrial oxidative phosphorylation of fatty acids (FAs) and glucose, with the remaining portion coming from a variety of sources, including fructose, lactate, ketone bodies (KB) and branched chain amino acids (BCAA). Increased FA intake and decreased utilization of glucose and lactic acid were observed in the diabetic hearts of animal models and diabetic patients. Moreover, the polyol pathway is activated, and fructose metabolism is enhanced. The use of ketones as energy sources in human diabetic hearts also increases significantly. Furthermore, elevated BCAA levels and impaired BCAA metabolism were observed in the hearts of diabetic mice and patients. The shift in energy substrate preference in diabetic hearts results in increased oxygen consumption and impaired oxidative phosphorylation, leading to diabetic cardiomyopathy. However, the precise mechanisms by which impaired myocardial metabolic alterations result in diabetes mellitus cardiac disease are not fully understood. Therefore, this review focuses on the molecular mechanisms involved in alterations of myocardial energy metabolism. It not only adds more molecular targets for the diagnosis and treatment, but also provides an experimental foundation for screening novel therapeutic agents for diabetic cardiomyopathy.

Keywords: cardiac function; diabetic cardiomyopathy; fatty acid oxidation; glucotoxicity; heart failure; metabolism

DOI: https://doi.org/10.3389/fcvm.2024.1375400

J Clin Med. 2024 Feb 20. pii: 1195. [Epub ahead of print]13(5):

Myocardial Metabolism in Heart Failure with Preserved Ejection Fraction.

John Aaron Henry, Liam S Couch, Oliver J Rider.

Heart failure with preserved ejection fraction (HFpEF) is increasingly prevalent and now accounts for half of all heart failure cases. This rise is largely attributed to growing rates of obesity, hypertension, and diabetes. Despite its prevalence, the pathophysiological mechanisms of HFpEF are not fully understood. The heart, being the most energy-demanding organ, appears to have a compromised bioenergetic capacity in heart failure, affecting all phenotypes and aetiologies. While metabolic disturbances in heart failure with reduced ejection fraction (HFrEF) have been extensively studied, similar insights into HFpEF are limited. This review collates evidence from both animal and human studies, highlighting metabolic dysregulations associated with HFpEF and its risk factors, such as obesity, hypertension, and diabetes. We discuss how changes in substrate utilisation, oxidative phosphorylation, and energy transport contribute to HFpEF. By delving into these pathological shifts in myocardial energy production, we aim to reveal novel therapeutic opportunities. Potential strategies include modulating energy substrates, improving metabolic efficiency, and enhancing critical metabolic pathways. Understanding these aspects could be key to developing more effective treatments for HFpEF.

Keywords: HFpEF; cardiac metabolism; energy production; heart failure; substrate utilisation

DOI: https://doi.org/10.3390/jcm13051195

Circulation. 2024 Apr 07.

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

BACKGROUND: Sodium glucose co-transporter 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 three patient populations (diabetes at high risk for atherosclerotic cardiovascular disease [ASCVD], heart failure [HF], or chronic kidney disease [CKD]). The outcomes of interest were MACE (composite of CV death, myocardial infarction [MI], or stroke), individual components of MACE (inclusive of fatal and non-fatal events), all-cause mortality, and death subtypes. Effect estimates for SGLT2i vs. placebo were meta-analyzed across trials and examined across key subgroups (established ASCVD, prior MI, diabetes, prior HF, albuminuria, CKD 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 ASCVD, HF, or CKD, respectively. SGLT2i reduced the rate of MACE by 9% (HR 0.91 [95% CI 0.87-0.96], p<0.0001) with a consistent effect across all three patient populations (I2=0%) and across all key subgroups. This effect was primarily driven by a reduction in CV death (HR 0.86 [0.81-0.92], p<0.0001), with no significant effect for MI in the overall population (HR 0.95 [0.87-1.04], p=0.29), and no effect on stroke (HR 0.99 [0.91-1.07], p=0.77). The benefit for CV death was driven primarily by reductions in HF death and sudden cardiac death (HR 0.68 [0.46-1.02] and HR 0.86 [0.78-0.95], respectively) and was generally consistent across subgroups, with the possible exception of being more apparent in those with albuminuria (Pint=0.02).
CONCLUSIONS: SGLT2i reduce the risk of MACE across a broad range of patients irrespective of ASCVD, diabetes, kidney function or other major clinical characteristics at baseline. This effect is driven primarily by a reduction of CV death, particularly HF and sudden cardiac death, without a significant effect on MI 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.

DOI: https://doi.org/10.1161/CIRCULATIONAHA.124.069568

Lancet. 2024 Apr 04. pii: S0140-6736(24)00469-0. [Epub ahead of print]

Semaglutide versus placebo in people with obesity-related heart failure with preserved ejection fraction: a pooled analysis of the STEP-HFpEF and STEP-HFpEF DM randomised trials.

STEP-HFpEF Trial Committees and Investigators

BACKGROUND: In the STEP-HFpEF (NCT04788511) and STEP-HFpEF DM (NCT04916470) trials, the GLP-1 receptor agonist semaglutide improved symptoms, physical limitations, bodyweight, and exercise function in people with obesity-related heart failure with preserved ejection fraction. In this prespecified pooled analysis of the STEP-HFpEF and STEP-HFpEF DM trials, we aimed to provide a more definitive assessment of the effects of semaglutide across a range of outcomes and to test whether these effects were consistent across key patient subgroups.
METHODS: We conducted a prespecified pooled analysis of individual patient data from STEP-HFpEF and STEP-HFpEF DM, randomised, double-blind, placebo-controlled trials at 129 clinical research sites in 18 countries. In both trials, eligible participants were aged 18 years or older, had heart failure with a left ventricular ejection fraction of at least 45%, a BMI of at least 30 kg/m2, New York Heart Association class II-IV symptoms, and a Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS; a measure of heart failure-related symptoms and physical limitations) of less than 90 points. In STEP-HFpEF, people with diabetes or glycated haemoglobin A1c concentrations of at least 6·5% were excluded, whereas for inclusion in STEP-HFpEF DM participants had to have been diagnosed with type 2 diabetes at least 90 days before screening and to have an HbA1c of 10% or lower. In both trials, participants were randomly assigned to either 2·4 mg semaglutide once weekly or matched placebo for 52 weeks. The dual primary endpoints were change from baseline to week 52 in KCCQ-CSS and bodyweight in all randomly assigned participants. Confirmatory secondary endpoints included change from baseline to week 52 in 6-min walk distance, a hierarchical composite endpoint (all-cause death, heart failure events, and differences in changes in KCCQ-CSS and 6-min walk distance); and C-reactive protein (CRP) concentrations. Heterogeneity in treatment effects was assessed across subgroups of interest. We assessed safety in all participants who received at least one dose of study drug.
FINDINGS: Between March 19, 2021 and March 9, 2022, 529 people were randomly assigned in STEP-HFpEF, and between June 27, 2021 and Sept 2, 2022, 616 were randomly assigned in STEP-HFpEF DM. Overall, 1145 were included in our pooled analysis, 573 in the semaglutide group and 572 in the placebo group. Improvements in KCCQ-CSS and reductions in bodyweight between baseline and week 52 were significantly greater in the semaglutide group than in the placebo group (mean between-group difference for the change from baseline to week 52 in KCCQ-CSS 7·5 points [95% CI 5·3 to 9·8]; p<0·0001; mean between-group difference in bodyweight at week 52 -8·4% [-9·2 to -7·5]; p<0·0001). For the confirmatory secondary endpoints, 6-min walk distance (mean between-group difference at week 52 17·1 metres [9·2 to 25·0]) and the hierarchical composite endpoint (win ratio 1·65 [1·42 to 1·91]) were significantly improved, and CRP concentrations (treatment ratio 0·64 [0·56 to 0·72]) were significantly reduced, in the semaglutide group compared with the placebo group (p<0·0001 for all comparisons). For the dual primary endpoints, the efficacy of semaglutide was largely consistent across multiple subgroups, including those defined by age, race, sex, BMI, systolic blood pressure, baseline CRP, and left ventricular ejection fraction. 161 serious adverse events were reported in the semaglutide group compared with 301 in the placebo group.
INTERPRETATION: In this prespecified pooled analysis of the STEP-HFpEF and STEP-HFpEF DM trials, semaglutide was superior to placebo in improving heart failure-related symptoms and physical limitations, and reducing bodyweight in participants with obesity-related heart failure with preserved ejection fraction. These effects were largely consistent across patient demographic and clinical characteristics. Semaglutide was well tolerated.
FUNDING: Novo Nordisk.

DOI: https://doi.org/10.1016/S0140-6736(24)00469-0

J Am Coll Cardiol. 2024 Apr 01. pii: S0735-1097(24)06757-3. [Epub ahead of print]

Left Ventricular Function, Congestion, and Effect of Empagliflozin on Heart Failure Risk After Myocardial Infarction.

BACKGROUND: Empagliflozin reduces the risk of heart failure (HF) hospitalizations but not all-cause mortality when started within 14 days of acute myocardial infarction (AMI).
OBJECTIVE: To evaluate the association between left ventricular ejection fraction (LVEF), congestion, or both on outcomes and the impact of empagliflozin in reducing HF risk post-MI.
METHODS: In the EMPACT-MI trial, patients were randomized within 14 days of an AMI complicated by either newly reduced LVEF<45%, congestion, or both to empagliflozin 10 mg daily or placebo and followed for a median of 17.9 months.
RESULTS: Among 6522 patients, the mean baseline LVEF was 41%+9%; 2648 patients (40.6%) presented with LVEF<45% alone, 1483 (22.7%) presented with congestion alone, and 2181 (33.4%) presented with both. Among patients in the placebo arm, multivariable adjusted risk for each 10-point reduction in LVEF included all-cause death or HF hospitalization (hazard ratio [HR] 1.49; 95%CI, 1.31-1.69; P<0.0001), first HF hospitalization (HR, 1.64; 95%CI, 1.37-1.96; P<0.0001), and total HF hospitalizations (rate ratio [RR], 1.89; 95%CI, 1.51-2.36; P<0.0001). Presence of congestion was also associated with a significantly higher risk for each of these outcomes (HR 1.52, 1.94, and RR 2.03, respectively). Empagliflozin reduced the risk for first (HR 0.77, 95%CI 0.60-0.98) and total (RR 0.67, 95%CI 0.50-0.89) HF hospitalization, irrespective of LVEF or congestion or both. The safety profile of empagliflozin was consistent across baseline LVEF and irrespective of congestion status.
CONCLUSIONS: In patients with AMI, severity of LV dysfunction and the presence of congestion was associated with worse outcomes. Empagliflozin reduced first and total HF hospitalizations across the range of LVEF with and without congestion.

Keywords: acute myocardial infarction; congestion; empagliflozin; heart failure; left ventricular dysfunction

DOI: https://doi.org/10.1016/j.jacc.2024.03.405