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Aims: Hyperactivity of Ca 2+ /calmodulin-dependent protein kinase II (CaMKII) has emerged as a central cause of pathologic remodelling in heart failure. It has been suggested that CaMKII-induced hyperphosphorylation of the ryanodine receptor 2 (RyR2) and consequently increased diastolic Ca 2+ leak from the sarcoplasmic reticulum (SR) is a crucial mechanism by which increased CaMKII activity leads to contractile dysfunction. We aim to evaluate the relevance of CaMKII-dependent RyR2 phosphorylation for CaMKII-induced heart failure development in vivo., Methods and Results: We crossbred CaMKIIδC overexpressing [transgenic (TG)] mice with RyR2-S2814A knock-in mice that are resistant to CaMKII-dependent RyR2 phosphorylation. Ca 2+ -spark measurements on isolated ventricular myocytes confirmed the severe diastolic SR Ca 2+ leak previously reported in CaMKIIδC TG [4.65 ± 0.73 mF/F 0 vs. 1.88 ± 0.30 mF/F 0 in wild type (WT)]. Crossing in the S2814A mutation completely prevented SR Ca 2+ -leak induction in the CaMKIIδC TG, both regarding Ca 2+ -spark size and frequency, demonstrating that the CaMKIIδC-induced SR Ca 2+ leak entirely depends on the CaMKII-specific RyR2-S2814 phosphorylation. Yet, the RyR2-S2814A mutation did not affect the massive contractile dysfunction (ejection fraction = 12.17 ± 2.05% vs. 45.15 ± 3.46% in WT), cardiac hypertrophy (heart weight/tibia length = 24.84 ± 3.00 vs. 9.81 ± 0.50 mg/mm in WT), or severe premature mortality (median survival of 12 weeks) associated with cardiac CaMKIIδC overexpression. In the face of a prevented SR Ca 2+ leak, the phosphorylation status of other critical CaMKII downstream targets that can drive heart failure, including transcriptional regulator histone deacetylase 4, as well as markers of pathological gene expression including Xirp2, Il6, and Col1a1, was equally increased in hearts from CaMKIIδC TG on a RyR WT and S2814A background., Conclusions: S2814 phosphoresistance of RyR2 prevents the CaMKII-dependent SR Ca 2+ leak induction but does not prevent the cardiomyopathic phenotype caused by enhanced CaMKIIδC activity. Our data indicate that additional mechanisms-independent of SR Ca 2+ leak-are critical for the maladaptive effects of chronically increased CaMKIIδC activity with respect to heart failure., (© 2024 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Ex situ heart perfusion (ESHP) has emerged as an important strategy to preserve donation after brain death (DBD) and donation after circulatory death (DCD) donor hearts. Clinically, both DBD and DCD hearts are successfully preserved using ESHP. Viability assessment is currently based on biochemical values, while a reliable method for graft function assessment in a physiologic working mode is unavailable. As functional assessment during ESHP has demonstrated the highest predictive value of outcome post-transplantation, this is an important area for improvement. In this study, a novel method for ex situ assessment of left ventricular function with pressure-volume loop analyses is evaluated. Ovine hearts were functionally evaluated during normothermic ESHP with the novel pressure-volume loop system. This system provides an afterload and adjustable preload to the left ventricle. By increasing the preload and measuring end-systolic elastance, the system could successfully assess the left ventricular function. End-systolic elastance at 60 min and 120 min was 2.8 ± 1.8 mmHg/mL and 2.7 ± 0.7 mmHg/mL, respectively. In this study we show a novel method for functional graft assessment with ex situ pressure-loop analyses during ESHP. When further validated, this method for pressure-volume assessments, could be used for better graft selection in both DBD and DCD donor hearts., Competing Interests: Authors BW, AvP, and FN were employed by XVIVO. ME holds a patent with XVIVO. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ertugrul, Puspitarani, Wijntjes, Vervoorn, Ballan, van der Kaaij, van Goor, Westenbrink, van der Plaats, Nijhuis, van Suylen and Erasmus.)

Background: High-density lipoprotein (HDL) is commonly characterized by its cholesterol concentration (HDL-C) and inverse association with atherosclerotic cardiovascular disease., Objectives: The authors sought to evaluate the association of HDL particle concentration (HDL-P), HDL particle size (HDL-size), HDL-C, and cholesterol content per particle (HDL-C/HDL-P) with risk of overall heart failure (HF) and subtypes., Methods: Participants from the Atherosclerosis Risk In Communities Study, Dallas Heart Study, Multi-Ethnic Study of Atherosclerosis, and Prevention of Renal and Vascular End-stage Disease studies without HF history were included. Associations of HDL-P, HDL-size, HDL-C, and HDL-C/HDL-P with risk of overall HF, HF with reduced and preserved ejection fraction were assessed using adjusted Cox models., Results: Among 16,925 participants (53.5% women; 21.8% Black), there were 612 incident HF events (3.6%) (HF with reduced ejection fraction, 309 [50.5%]; HF preserved ejection fraction, 303 [49.5%]) over median follow-up of 11.4 years. In adjusted models, higher HDL-P was significantly associated with lower HF risk (HR of highest vs lowest tertile of HDL-P: 0.76 [95% CI: 0.62-0.93]). Larger HDL-size was significantly associated with higher overall HF risk (HR of largest vs smallest tertile of HDL-size: 1.27 [95% CI: 1.03-1.58]). HF risk associated with HDL-P and HDL-size was similar for HF subtypes. In adjusted analyses, there was no significant association between HDL-C and HF risk. Higher HDL-C/HDL-P was significantly associated with higher overall HF risk (HR of highest vs lowest tertile of HDL-C/HDL-P: 1.29 [95% CI: 1.04-1.60])., Conclusions: Higher HDL-P was associated with a lower risk of HF. In contrast, larger HDL-size was associated with higher risk of HF and there was no significant association observed between HDL-C and HF risk after accounting for cardiovascular risk factors., Competing Interests: Funding Support and Author Disclosures The ARIC study has been funded in whole or in part with federal funds from the National Heart, Lung, and Blood Institute, National Institutes of Health, Department of Health and Human Services, under contracts HHSN268201700001I, HHSN268201700002I, HHSN268201700003I, HHSN268201700005I, and HHSN268201700004I. The Dallas Heart Study was funded by a grant from the Donald W. Reynolds Foundation. The Multi-Ethnic Study of Atherosclerosis was supported by the National Heart, Lung, and Blood Institute (R01 HL071739 and contracts N01-HC-95159, N01-HC-95160, N01-HC-95161, N01-HC-95162, N01-HC-95163, N01-HC-95164, N01-HC-95165, and N01-C-95169). The PREVEND cohort study was supported by The Dutch Kidney Foundation which supported the infrastructure of the PREVEND program from 1997 to 2003 (Grant E.033). The University Medical Center Groningen supported the infrastructure from 2003 to 2006. Dr Pandey is supported by the Texas Health Resources Clinical Scholarship, the Gilead Sciences Research Scholar Program, the National Institute of Aging GEMSSTAR Grant (1R03AG067960-01), and Applied Therapeutics; has served on the advisory board for Roche Diagnostics; and has received nonfinancial support from Pfizer and Merck. Dr Patel has served as a consultant to Novo Nordisk. Dr Segar has received speaker fees from Merck and is on the advisory board of descendantsDNA. Dr Shapiro has received grants from Amgen, Boehringer Ingelheim, 89Bio, Esperion, Novartis, Ionis, Merck, and New Amsterdam; has served on scientific advisory boards for Amgen, Agepha, Ionis, Novartis, Precision BioScience, New Amsterdam, and Merck; and has served as a consultant to Ionis, Novartis, Regeneron, Aidoc, Shanghai Pharma Biotherapeutics, Kaneka, and Novo Nordisk. Dr Connelly is an employee of Labcorp. Dr Rohatgi has received a research grant from CSL Behring; has served as a collaborator to Quest; has served as a consultant to HDL Diagnostics, JP Morgan, Johnson and Johnson, and Raydel. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024. Published by Elsevier Inc.)

Introduction: Heart failure (HF) with mildly reduced and preserved ejection fraction (HFmrEF/HFpEF) is often accompanied by atrial dysfunction. It has been suggested that specific ectopic fat depots, such as epicardial adipose tissue (EAT), may directly influence the myocardial cells and, therefore, be involved in the pathophysiology of atrial mechanical dysfunction. In this study, we aimed to investigate the association between EAT and left atrial (LA) mechanical dysfunction., Methods and Results: In total, 82 patients with symptomatic HF and left ventricular ejection fraction > 40% were prospectively enrolled. All patients underwent CMR while in sinus rhythm. LA mechanical dysfunction was defined as the presence of LA end-systolic volume index > 52 mL/m 2 and LA reservoir strain < 23%. EAT volume was indexed for body surface area. Mean age was 69 ± 10 years, 42 (51%) were women and mean body mass index (BMI) was 29 ± 6 kg/m 2 . Mean LVEF was 55 ± 9% and 34 (41%) patients had LA mechanical dysfunction. In patients with LA mechanical dysfunction, the EAT volume was significantly higher than in patients without LA mechanical dysfunction (90 vs 105 mL/m 2 , p = 0.02) while BMI was similar. In multivariable logistic regression analyses, increased EAT remained significantly associated with LA mechanical dysfunction (OR 1.31, 95% CI 1.03-1.66, p = 0.03)., Conclusion: Increased EAT was associated with LA mechanical dysfunction in patients with HFmrEF and HFpEF. Further research is needed to elucidate the exact mechanisms that underlie this association., (© 2024. The Author(s).)

Background: Heart failure (HF) features a shift in metabolism towards enhanced utilization of ketone bodies. While elevations in plasma natriuretic peptides represent a biochemical hallmark of HF, natriuretic peptides may promote lipolysis, thereby contributing to fatty acid availability for ketogenesis. Methods: We cross-sectionally tested to what extent fasting plasma total ketone bodies (measured using nuclear magnetic resonance spectroscopy) are associated with N-terminal pro-BNP (NT-proBNP; electrochemiluminescent sandwich immunoassay) in individuals with and without HF. Results: Among 6217 participants from the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) study, 203 were identified with HF. NT-proBNP was four-fold and total ketone bodies were 25% higher in HF participants (each p < 0.001). In both participants with and without HF, total ketone body levels correlated with NT-proBNP (r = 0.116 and 0.185, respectively; p < 0.001). In multivariable linear regression analysis adjusted for relevant covariates, total ketone bodies remained associated with NT-proBNP in the whole cohort (std β = 0.08, p < 0.001), without a difference in participants with and without HF ( p interaction: 0.52). Conclusion: This general population-based study reveals an independent association of fasting total body ketone bodies with plasma NT-proBNP. Our findings suggest that a metabolic defense mechanism could be operative, providing the myocardium with ketone bodies to meet its energy demands.

Background: The optimal approach to identify individuals with diabetes who are at a high risk for developing heart failure (HF) to inform implementation of preventive therapies is unknown, especially in those without atherosclerotic cardiovascular disease (ASCVD)., Methods: Adults with diabetes and no HF at baseline from 7 community-based cohorts were included. Participants without ASCVD who were at high risk for developing HF were identified using 1-step screening strategies: risk score (WATCH-DM [Weight, Age, Hypertension, Creatinine, HDL-C, Diabetes Control, QRS Duration, MI, and CABG] ≥12), NT-proBNP (N-terminal pro-B-type natriuretic peptide ≥125 pg/mL), hs-cTn (high-sensitivity cardiac troponin T ≥14 ng/L; hs-cTnI ≥31 ng/L), and echocardiography-based diabetic cardiomyopathy (echo-DbCM; left atrial enlargement, left ventricular hypertrophy, or diastolic dysfunction). High-risk participants were also identified using 2-step screening strategies with a second test to identify residual risk among those deemed low risk by the first test: WATCH-DM/NT-proBNP, NT-proBNP/hs-cTn, NT-proBNP/echo-DbCM. Across screening strategies, the proportion of HF events identified, 5-year number needed to treat and number needed to screen to prevent 1 HF event with an SGLT2i (sodium-glucose cotransporter 2 inhibitor) among high-risk participants, and cost of screening were estimated., Results: The initial study cohort included 6293 participants (48.2% women), of whom 77.7% without prevalent ASCVD were evaluated with different HF screening strategies. At 5-year follow-up, 6.2% of participants without ASCVD developed incident HF. The 5-year number needed to treat to prevent 1 HF event with an SGLT2i among participants without ASCVD was 43 (95% CI, 29-72). In the cohort without ASCVD, high-risk participants identified using 1-step screening strategies had a low 5-year number needed to treat (22 for NT-proBNP to 37 for echo-DbCM). However, a substantial proportion of HF events occurred among participants identified as low risk using 1-step screening approaches (29% for echo-DbCM to 47% for hs-cTn). Two-step screening strategies captured most HF events (75-89%) in the high-risk subgroup with a comparable 5-year number needed to treat as the 1-step screening approaches (30-32). The 5-year number needed to screen to prevent 1 HF event was similar across 2-step screening strategies (45-61). However, the number of tests and associated costs were lowest for WATCH-DM/NT-proBNP ($1061) compared with other 2-step screening strategies (NT-proBNP/hs-cTn: $2894; NT-proBNP/echo-DbCM: $16 358)., Conclusions: Selective NT-proBNP testing based on the WATCH-DM score efficiently identified a high-risk primary prevention population with diabetes expected to derive marked absolute benefits from SGLT2i to prevent HF., Competing Interests: Disclosures Dr Patel has served as a consultant to Novo Nordisk. Dr Segar has received honoraria from Merck. Dr Klonoff has served as a consultant for Afon, Atropos Health, Better Therapeutics, Glucotrack, Lifecare, Novo, Samsung, and Thirdwayv. Dr Khan has received personal fees from Merck. Dr Lam has received research support from AstraZeneca, Bayer, Boston Scientific, and Roche Diagnostics; has served as a consultant or on advisory boards/steering committees/executive committees for Actelion, Alleviant Medical, Allysta, Amgen, ANaCardio AB, Applied Therapeutics, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Cytokinetics, Darma, EchoNous, Impulse Dynamics, Ionis Pharmaceutical, Janssen Research and Development, Medscape, Merck, Novartis, Novo Nordisk, Radcliffe Group, Roche Diagnostics, Sanofi, Siemens Healthcare Diagnostics, Us2.ai, and WebMD Global; and has served as cofounder and nonexecutive director of Us2.ai. Dr Verma holds a Tier 1 Canada Research Chair in Cardiovascular Surgery; has received research grants and honoraria from Amarin, Amgen, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Eli Lilly, HLS Therapeutics, Janssen, Novartis, Novo Nordisk, PhaseBio, and Pfizer; has received honoraria from Sanofi, Sun Pharmaceuticals, and the Toronto Knowledge Translation Working Group; is a member of the scientific excellence committee of the EMPEROR-Reduced trial (Empagliflozin Outcome Trial in Patients with Chronic Heart Failure With Reduced Ejection Fraction); has served as a national lead investigator of the DAPA-HF (Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure) and EMPEROR-Reduced trials; and is the president of the Canadian Medical and Surgical Knowledge Translation Research Group, a federally incorporated not-for-profit physician organization. Dr Nasir is on the advisory board of Amgen, Novartis, and Novo Nordisk, and his research is partly supported by the Jerold B. Katz Academy of Translational Research. Dr Butler has served as a consultant for Abbott, American Regent, Amgen, Applied Therapeutic, AstraZeneca, Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Cardiac Dimension, Cardior, CVRx, Cytokinetics, Daxor Edwards, Element Science, Innolife, Impulse Dynamics, Imbria, Inventiva, Lexicon, Lilly, LivaNova, Janssen, Medtronics, Merck, Occlutech, Owkin, Novartis, Novo Nordisk, Pfizer, Pharmacosmos, Pharmain, Prolaio, Roche, Secretome, Sequana, SQ Innovation, Tenex, and Vifor. Dr Vaduganathan is supported by the KL2/Catalyst Medical Research Investigator Training award from Harvard Catalyst (National Institutes of Health/National Center for Advancing Translational Sciences Award UL 1TR002541) and has served on advisory boards or has received research grant support from American Regent, Amgen, AstraZeneca, Baxter Healthcare, Bayer AG, Boehringer Ingelheim, Cytokinetics, and Relypsa. Dr Pandey has received research support from the National Institute on Aging GEMSSTAR Grant (1R03AG067960-01) and the National Institute on Minority Health and Disparities (R01MD017529). Dr Pandey has received grant funding (to the institution) from Applied Therapeutics, Gilead Sciences, Ultromics, Myovista, and Roche; has served as a consultant for and/or has received honoraria outside of the present study as an advisor/consultant for Tricog Health Inc, Lilly USA, Rivus, Cytokinetics, Roche Diagnostics, Sarfez Therapeutics, Edwards Lifesciences, Merck, Bayer, Novo Nordisk, Alleviant, Axon Therapies; and has received nonfinancial support from Pfizer and Merck. Dr Pandey is also a consultant for Palomarin Inc with stocks compensation. The other authors report no conflicts.

A Kinase Interacting Protein 1 (AKIP1) is a signalling adaptor that promotes mitochondrial respiration and attenuates mitochondrial oxidative stress in cultured cardiomyocytes. We sought to determine whether AKIP1 influences mitochondrial function and the mitochondrial adaptation in response to exercise in vivo. We assessed mitochondrial respiratory capacity, as well as electron microscopy and mitochondrial targeted-proteomics in hearts from mice with cardiomyocyte-specific overexpression of AKIP1 (AKIP1-TG) and their wild type (WT) littermates. These parameters were also assessed after four weeks of voluntary wheel running. In contrast to our previous in vitro study, respiratory capacity measured as state 3 respiration on palmitoyl carnitine was significantly lower in AKIP1-TG compared to WT mice, whereas state 3 respiration on pyruvate remained unaltered. Similar findings were observed for maximal respiration, after addition of FCCP. Mitochondrial DNA damage and oxidative stress markers were not elevated in AKIP1-TG mice and gross mitochondrial morphology was similar. Mitochondrial targeted-proteomics did reveal reductions in mitochondrial proteins involved in energy metabolism. Exercise performance was comparable between genotypes, whereas exercise-induced cardiac hypertrophy was significantly increased in AKIP1-TG mice. After exercise, mitochondrial state 3 respiration on pyruvate substrates was significantly lower in AKIP1-TG compared with WT mice, while respiration on palmitoyl carnitine was not further decreased. This was associated with increased mitochondrial fission on electron microscopy, and the activation of pathways associated with mitochondrial fission and mitophagy. This study suggests that AKIP1 regulates the mitochondrial proteome involved in energy metabolism and promotes mitochondrial turnover after exercise. Future studies are required to unravel the mechanistic underpinnings and whether the mitochondrial changes are required for the AKIP1-induced physiological cardiac growth., (© 2023. The Author(s).)

Competing Interests: Conflict of interest: R.A.d.B. is president-elect of the Dutch Cardiac Society (NVVC), member of the Executive Committee of the DELIVER-trial and has received grants from AstraZeneca, Abbott, Boehringer Ingelheim, Cardior Pharmaceuticals GmbH, Ionis Pharmaceuticals, Inc., Novo Nordisk, and Roche in the last 36 months. R.A.d.B. has received payment or honoraria from Abbott, AstraZeneca, Bayer, Bristol Myers Squibb, Novartis, and Roche in the last 36 months. J.P.v.T. has received consulting fees from StrideBio in the last 36 months. A.A.M.W. has received grants from the Dutch Heart Foundation and consulting fees from LQT Therapeutics and ARMGO in the last 36 months. A.A.M.W. additionally is a member of the advisory board of the Leap Trial.

A Kinase Interacting Protein 1 (AKIP1) is a signalling adaptor that promotes physiological hypertrophy in vitro. The purpose of this study is to determine if AKIP1 promotes physiological cardiomyocyte hypertrophy in vivo. Therefore, adult male mice with cardiomyocyte-specific overexpression of AKIP1 (AKIP1-TG) and wild type (WT) littermates were caged individually for four weeks in the presence or absence of a running wheel. Exercise performance, heart weight to tibia length (HW/TL), MRI, histology, and left ventricular (LV) molecular markers were evaluated. While exercise parameters were comparable between genotypes, exercise-induced cardiac hypertrophy was augmented in AKIP1-TG vs. WT mice as evidenced by an increase in HW/TL by weighing scale and in LV mass on MRI. AKIP1-induced hypertrophy was predominantly determined by an increase in cardiomyocyte length, which was associated with reductions in p90 ribosomal S6 kinase 3 (RSK3), increments of phosphatase 2A catalytic subunit (PP2Ac) and dephosphorylation of serum response factor (SRF). With electron microscopy, we detected clusters of AKIP1 protein in the cardiomyocyte nucleus, which can potentially influence signalosome formation and predispose a switch in transcription upon exercise. Mechanistically, AKIP1 promoted exercise-induced activation of protein kinase B (Akt), downregulation of CCAAT Enhancer Binding Protein Beta (C/EBPβ) and de-repression of Cbp/p300 interacting transactivator with Glu/Asp rich carboxy-terminal domain 4 (CITED4). Concludingly, we identified AKIP1 as a novel regulator of cardiomyocyte elongation and physiological cardiac remodelling with activation of the RSK3-PP2Ac-SRF and Akt-C/EBPβ-CITED4 pathway. These findings suggest that AKIP1 may serve as a nodal point for physiological reprogramming of cardiac remodelling., (© 2023. The Author(s).)

A physiological increase in cardiac workload results in adaptive cardiac remodeling, characterized by increased oxidative metabolism and improvements in cardiac performance. Insulin-like growth factor-1 (IGF-1) has been identified as a critical regulator of physiological cardiac growth, but its precise role in cardiometabolic adaptations to physiological stress remains unresolved. Mitochondrial calcium (Ca 2+ ) handling has been proposed to be required for sustaining key mitochondrial dehydrogenase activity and energy production during increased workload conditions, thus ensuring the adaptive cardiac response. We hypothesized that IGF-1 enhances mitochondrial energy production through a Ca 2+ -dependent mechanism to ensure adaptive cardiomyocyte growth. We found that stimulation with IGF-1 resulted in increased mitochondrial Ca 2+ uptake in neonatal rat ventricular myocytes and human embryonic stem cell-derived cardiomyocytes, estimated by fluorescence microscopy and indirectly by a reduction in the pyruvate dehydrogenase phosphorylation. We showed that IGF-1 modulated the expression of mitochondrial Ca 2+ uniporter (MCU) complex subunits and increased the mitochondrial membrane potential; consistent with higher MCU-mediated Ca 2+ transport. Finally, we showed that IGF-1 improved mitochondrial respiration through a mechanism dependent on MCU-mediated Ca 2+ transport. In conclusion, IGF-1-induced mitochondrial Ca 2+ uptake is required to boost oxidative metabolism during cardiomyocyte adaptive growth., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer SM declared a past co-authorship with the authors PSA, NB, PVDM and DW to the handling editor., (Copyright © 2023 Sánchez-Aguilera, López-Crisosto, Norambuena-Soto, Penannen, Zhu, Bomer, Hoes, Van Der Meer, Chiong, Westenbrink and Lavandero.)

Aims: Management of comorbidities represents a critical step in optimal treatment of heart failure (HF) patients. However, minimal attention has been paid whether comorbidity burden and their prognostic value changes over time. Therefore, we examined the association between comorbidities and clinical outcomes in HF patients between 2002 and 2017., Methods and Results: The 2002-HF cohort consisted of patients from The Coordinating Study Evaluating Outcomes of Advising and Counseling in Heart Failure (COACH) trial (n = 1,032). The 2017-HF cohort were outpatient HF patients enrolled after hospitalization for HF in a tertiary referral academic hospital (n = 382). Kaplan meier and cox regression analyses were used to assess the association of comorbidities with HF hospitalization and all-cause mortality. Patients from the 2017-cohort were more likely to be classified as HF with preserved ejection fraction (24 vs 15%, p < 0.001), compared to patients from the 2002-cohort. Comorbidity burden was comparable between both cohorts (mean of 3.9 comorbidities per patient) and substantially increased with age. Higher comorbidity burden was significantly associated with a comparable increased risk for HF hospitalization and all-cause mortality (HR 1.12 [1.02-1.22] and HR 1.18 [1.05-1.32]), in the 2002- and 2017-cohort respectively. When assessing individual comorbidities, obesity yielded a statistically higher prognostic effect on outcome in the 2017-cohort compared to the 2002-HF cohort (p for interaction 0.026)., Conclusion: Despite major advances in HF treatment over the past decades, comorbidity burden remains high in HF and influences outcome to a large extent. Obesity emerges as a prominent comorbidity, and efforts should be made for prevention and treatment. Created with BioRender.com., (© 2022. The Author(s).)

Background: Ketone bodies are endogenous fuels produced by the liver under conditions of metabolic or neurohormonal stress. Circulating ketone bodies are increased in patients with chronic heart failure (HF), yet little is known about the effect of acute HF on ketosis. We tested the hypothesis that ketogenesis is increased in patients with acute decompensated HF., Methods and Results: This was a post hoc analysis of 79 patients with acute HF included in the EMPA-RESPONSE-AHF trial, which compared sodium-dependent glucose-cotransporter protein 2 inhibitor treatment with empagliflozin for 30 days with placebo in patients with acute HF [NCT03200860]. Plasma concentrations of ketone bodies acetone, β-hydroxybutyrate, and acetoacetate were measured at baseline and 5 different timepoints. Changes in ketone bodies over time were monitored using repeated measures analysis of variance. In the total cohort, median total ketone body concentration was 251 µmol/L (interquartile range, 178-377 µmol/L) at baseline, which gradually decreased to 202 µmol/L (interquartile range, 156-240 µmol/L) at day 30 (P = .041). Acetone decreased from 60 µmol/L (interquartile range, 34-94 µmol/L) at baseline to 30 µmol/L (interquartile range, 21-42 µmol/L) ( P < .001), whereas β-hydroxybutyrate and acetoacetate remained stable over time. Higher acetone concentrations were correlated with higher N-terminal pro brain natriuretic peptide levels (r = 0.234; P = .039). Circulating ketone bodies did not differ between patients treated with empagliflozin or placebo throughout the study period. A higher acetone concentration at baseline was univariately associated with a greater risk of the composite end point, including in-hospital worsening HF, HF rehospitalizations, and all-cause mortality after 30 days. However, after adjustment for age and sex, acetone did not remain an independent predictor for the combined end point., Conclusions: Circulating ketone body concentrations, and acetone in particular, were significantly higher during an episode of acute decompensated HF compared with after stabilization. Treatment with empagliflozin did not affect ketone body concentrations in patients with acute HF., Competing Interests: Disclosures The UMCG, which employs several of the authors, received research grants and/or fees from AstraZeneca, Abbott, Boehringer Ingelheim, Cardior Pharmaceuticals Gmbh, Ionis Pharmaceuticals, Inc., Novo Nordisk, and Roche. Dr. Voorrips. has received speaker fees from Astra Zeneca. Dr. de Boer has received grants from the Netherlands Heart Foundation (DOUBLE DOSE 2020) and the European Research Council (ERC CoG 818715, SECRETE-HF) and received speaker fees from Abbott, AstraZeneca, Bayer, Novartis, and Roche. Dr. Connelly is an employee of LabCorp. Dr. van Veldhuisen received consultancy fees and/or grants from Novartis, Novo Nordisk, Vifor Pharma, Astra Zeneca, Pfizer, Pharmacosmos, Pharma Nord and Ionis. Dr. Voors has received research support and/or has been a consultant for Amgen, AstraZeneca, Bayer AG, Boehringer Ingelheim, Cytokinetics, Merck, Myokardia, Novo Nordisk, Novartis, and Roche Diagnostics. Dr. Damman received speaker fees Abbott, Boehringer Ingelheim, Astra Zeneca. BDW has received consulting fees from Boehringer Ingelheim, Novartis, Astra Zeneca and received research grants from Siemens, Bristol-Myers Squibb, Dutch Heart foundation. All other authors have nothing to disclose., (Copyright © 2022 University Medical Center Groningen. Published by Elsevier Inc. All rights reserved.)

Obesity is very common in patients with heart failure with preserved ejection fraction (HFpEF) and it has been suggested that obesity plays an important role in the pathophysiology of this disease. While body mass index defines the presence of obesity, this measure provides limited information on visceral adiposity, which is probably more relevant in the pathophysiology of HFpEF. Epicardial adipose tissue is the visceral fat situated directly adjacent to the heart and recent data demonstrate that accumulation of epicardial adipose tissue is associated with the onset, symptomatology and outcome of HFpEF. However, the mechanisms by which epicardial adipose tissue may be involved in HFpEF remain unclear. It is also questioned whether epicardial adipose tissue may be a specific target for therapy for this disease. In the present review, we describe the physiology of epicardial adipose tissue and the pathophysiological transformation of epicardial adipose tissue in response to chronic inflammatory diseases, and we postulate conceptual mechanisms on how epicardial adipose tissue may be involved in HFpEF pathophysiology. Lastly, we outline potential treatment strategies, knowledge gaps and directions for further research., (© 2022 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

The heart is metabolically flexible. Under physiological conditions, it mainly uses lipids and glucose as energy substrates. In uncontrolled diabetes, the heart switches towards predominant lipid utilization, which over time is detrimental to cardiac function. Additionally, diabetes is accompanied by high plasma ketone levels and increased utilization of energy provision. The administration of exogenous ketones is currently being investigated for the treatment of cardiovascular disease. Yet, it remains unclear whether increased cardiac ketone utilization is beneficial or detrimental to cardiac functioning. The mechanism of lipid-induced cardiac dysfunction includes disassembly of the endosomal proton pump (named vacuolar-type H+-ATPase; v-ATPase) as the main early onset event, followed by endosomal de-acidification/dysfunction. The de-acidified endosomes can no longer serve as a storage compartment for lipid transporter CD36, which then translocates to the sarcolemma to induce lipid accumulation, insulin resistance, and contractile dysfunction. Lipid-induced v-ATPase disassembly is counteracted by the supply of specific amino acids. Here, we tested the effect of ketone bodies on v-ATPase assembly status and regulation of lipid uptake in rodent/human cardiomyocytes. 3-β-hydroxybutyrate (3HB) exposure induced v-ATPase disassembly and the entire cascade of events leading to contractile dysfunction and insulin resistance, similar to conditions of lipid oversupply. Acetoacetate addition did not induce v-ATPase dysfunction. The negative effects of 3HB could be prevented by addition of specific amino acids. Hence, in sedentary/prediabetic subjects ketone bodies should be used with caution because of possible aggravation of cardiac insulin resistance and further loss of cardiac function. When these latter maladaptive conditions would occur, specific amino acids could potentially be a treatment option.

Despite the constant improvement of therapeutical options, heart failure (HF) remains associated with high mortality and morbidity. While new developments in guideline-recommended therapies can prolong survival and postpone HF hospitalizations, impaired exercise capacity remains one of the most debilitating symptoms of HF. Exercise intolerance in HF is multifactorial in origin, as the underlying cardiovascular pathology and reactive changes in skeletal muscle composition and metabolism both contribute. Recently, sodium-related glucose transporter 2 (SGLT2) inhibitors were found to improve cardiovascular outcomes significantly. Whilst much effort has been devoted to untangling the mechanisms responsible for these cardiovascular benefits of SGLT2 inhibitors, little is known about the effect of SGLT2 inhibitors on exercise performance in HF. This review provides an overview of the pathophysiological mechanisms that are responsible for exercise intolerance in HF, elaborates on the potential SGLT2-inhibitor-mediated effects on these phenomena, and provides an up-to-date overview of existing studies on the effect of SGLT2 inhibitors on clinical outcome parameters that are relevant to the assessment of exercise capacity. Finally, current gaps in the evidence and potential future perspectives on the effects of SGLT2 inhibitors on exercise intolerance in chronic HF are discussed.

Heart failure (HF) remains a disease with immense global health burden. During the development of HF, the myocardium and therefore cardiac metabolism undergoes specific changes, with decreased long-chain fatty acid oxidation and increased anaerobic glycolysis, diminishing the overall energy yield. Based on the dogma that the failing heart is oxygen-deprived and on the fact that carbohydrates are more oxygen-efficient than FA, metabolic HF drugs have so far aimed to stimulate glucose oxidation or inhibit FA oxidation. Unfortunately, these treatments have failed to provide meaningful clinical benefits. We believe it is time to rethink the concept that fat is harmful to the failing heart. In this review we discuss accumulating evidence that short-chain fatty acids (SCFAs) may be an effective fuel for the failing heart. In contrast to long-chain fatty acids, SCFAs are readily taken up and oxidized by the heart and could serve as a nutraceutical treatment strategy. In addition, we discuss how SCFAs activate pathways that increase long chain fatty acid oxidation, which could help increase the overall energy availability. Another potential beneficial effect we discuss lies within the anti-inflammatory effect of SCFAs, which has shown to inhibit cardiac fibrosis - a key pathological process in the development of HF., Competing Interests: The UMCG, which employs KN and BW, has received research grants and/or fees from AstraZeneca, Abbott, Boehringer Ingelheim, Cardior Pharmaceuticals Gmbh, Ionis Pharmaceuticals, Inc., Novo Nordisk, and Roche. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Palm, Nijholt, Bakker and Westenbrink.)

Background: Coronary artery disease (CAD) burden for society is expected to steeply increase over the next decade. Improved feasibility and efficiency of preventive strategies is necessary to flatten the curve. Acute myocardial infarction (AMI) is the main determinant of CAD-related mortality and morbidity, and predominantly occurs in individuals with more advanced stages of CAD causing subclinical myocardial ischemia (obstructive CAD; OCAD). Unfortunately, OCAD can remain subclinical until its destructive presentation with AMI or sudden death. Current primary preventive strategies are not designed to differentiate between non-OCAD and OCAD and the opportunity is missed to treat individuals with OCAD more aggressively., Methods: EARLY-SYNERGY is a multicenter, randomized-controlled clinical trial in individuals with coronary artery calcium (CAC) presence to study (1.) the yield of cardiac magnetic resonance stress myocardial perfusion imaging (CMR-MPI) for early OCAD diagnosis and (2) whether early OCAD diagnosis improves outcomes. Individuals with CAC score ≥300 objectified in 2 population-based trials (ROBINSCA; ImaLife) are recruited for study participation. Eligible candidates are randomized 1:1 to cardiac magnetic resonance stress myocardial perfusion imaging (CMR-MPI) or no additional functional imaging. In the CMR-MPI arm, feedback on imaging results is provided to primary care provider and participant in case of guideline-based actionable findings. Participants are followed-up for clinical events, healthcare utilization and quality of life., Conclusions: EARLY-SYNERGY is the first randomized-controlled clinical trial designed to test the hypothesis that subclinical OCAD is widely present in the general at-risk population and that early differentiation of OCAD from non-OCAD followed by guideline-recommended treatment improves outcomes., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Aims: Epicardial adipose tissue (EAT) is increasingly recognized as an important factor in the pathophysiology of heart failure (HF). Cardiac magnetic resonance (CMR) imaging is the gold-standard imaging modality to evaluate EAT size, but in contrast to echocardiography, CMR is costly and not widely available. We investigated EAT thickness on echocardiography in relation to EAT volume on CMR, and we assessed the agreement between observers for measuring echocardiographic EAT., Methods and Results: Patients with HF and left ventricular ejection fraction >40% were enrolled. All patients underwent CMR imaging and transthoracic-echocardiography. EAT volume was quantified on CMR short-axis cine-stacks. Echocardiographic EAT thickness was measured on parasternal long-axis and short-axis views. Linear regression analyses were used to assess the association between EAT volume on CMR and EAT thickness on echocardiography. Intraclass correlation coefficient (ICC) was used to assess the interobserver agreement as well as the intraobserver agreement. EAT on CMR and echocardiography was evaluated in 117 patients (mean age 71 ± 10 years, 49% women and mean left ventricular ejection fraction 54 ± 7%). Mean EAT volume on CMR was 202 ± 64 mL and ranged from 80 to 373 mL. Mean EAT thickness on echocardiography was 3.8 ± 1.5 mm and ranged from 1.7 to 10.2 mm. EAT volume on CMR and EAT thickness on echocardiography were significantly correlated (junior-observer: r = 0.62, P < 0.001, senior-observer: r = 0.33, P < 0.001), and up to one-third of the variance in EAT volume was explained by EAT thickness (R 2  = 0.38, P < 0.001). The interobserver agreement between junior and senior observers for measuring echocardiographic EAT was modest [ICC, 0.65 (95% confidence interval (CI) 0.47-0.77], whereas the intraobserver agreement was good (ICC 0.98, 95% CI 0.84-0.99)., Conclusions: There was a modest correlation between EAT volume on CMR and EAT thickness on echocardiography. Limited agreement between junior and senior observers for measuring echocardiographic EAT was observed. EAT thickness on echocardiography is limited in estimating EAT volume., (© 2022 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Background: Epicardial adipose tissue (EAT) accumulation is thought to play a role in the pathophysiology of heart failure (HF) with mid-range and preserved ejection fraction, but its effect on outcome is unknown. We evaluated the prognostic value of EAT volume measured with cardiac magnetic resonance in patients with HF with mid-range ejection fraction and HF with preserved ejection fraction., Methods: Patients enrolled in a prospective multicenter study that investigated the value of implantable loop-recorders in HF with mid-range ejection fraction and HF with preserved ejection fraction were analyzed. EAT volume was quantified with cardiac magnetic resonance. Main outcome was the composite of all-cause mortality and first HF hospitalizations. Hazard ratios (HR) and 95% CI are described per SD increase in EAT., Results: We studied 105 patients (mean age 72±8 years, 50% women, and mean left ventricular ejection fraction 53±8%). During median follow-up of 24 (17-25) months, 31 patients (30%) died or were hospitalized for HF. In univariable analysis, EAT was significantly associated with a higher risk of the composite outcome (HR, 1.76 [95% CI, 1.24-2.50], P =0.001), and EAT remained associated with outcome after adjustment for age, sex, and body mass index (HR, 1.61 [95% CI, 1.13-2.31], P =0.009), and after adjustment for New York Heart Association functional class and N-terminal of pro-brain natriuretic peptide (HR, 1.53 [95% CI, 1.04-2.24], P =0.03). Furthermore, EAT was associated with all-cause mortality alone (HR, 2.06 [95% CI, 1.26-3.37], P =0.004) and HF hospitalizations alone (HR, 1.54 [95% CI, 1.04-2.30], P =0.03)., Conclusions: EAT accumulation is associated with adverse prognosis in patients with HF with mid-range ejection fraction and HF with preserved ejection fraction. This finding supports the importance of EAT in these patients with HF., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT01989299.

Background: The p.Arg14del (c.40&#95;42delAGA) phospholamban (PLN) pathogenic variant is a founder mutation that causes dilated cardiomyopathy (DCM) and arrhythmogenic cardiomyopathy (ACM). Carriers are at increased risk of malignant ventricular arrhythmias and heart failure, which has been ascribed to cardiac fibrosis. Importantly, cardiac fibrosis appears to be an early feature of the disease, occurring in many presymptomatic carriers before the onset of overt disease. As with most monogenic cardiomyopathies, no evidence-based treatment is available for presymptomatic carriers., Aims: The PHOspholamban RElated CArdiomyopathy intervention STudy (iPHORECAST) is designed to demonstrate that pre-emptive treatment of presymptomatic PLN p.Arg14del carriers using eplerenone, a mineralocorticoid receptor antagonist with established antifibrotic effects, can reduce disease progression and postpone the onset of overt disease., Methods: iPHORECAST has a multicentre, prospective, randomised, open-label, blinded endpoint (PROBE) design. Presymptomatic PLN p.Arg14del carriers are randomised to receive either 50 mg eplerenone once daily or no treatment. The primary endpoint of the study is a multiparametric assessment of disease progression including cardiac magnetic resonance parameters (left and right ventricular volumes, systolic function and fibrosis), electrocardiographic parameters (QRS voltage, ventricular ectopy), signs and/or symptoms related to DCM and ACM, and cardiovascular death. The follow-up duration is set at 3 years., Baseline Results: A total of 84 presymptomatic PLN p.Arg14del carriers (n = 42 per group) were included. By design, at baseline, all participants were in New York Heart Association (NHYA) class I and had a left ventricular ejection fraction > 45% and < 2500 ventricular premature contractions during 24-hour Holter monitoring. There were no statistically significant differences between the two groups in any of the baseline characteristics. The study is currently well underway, with the last participants expected to finish in 2021., Conclusion: iPHORECAST is a multicentre, prospective randomised controlled trial designed to address whether pre-emptive treatment of PLN p.Arg14del carriers with eplerenone can prevent or delay the onset of cardiomyopathy. iPHORECAST has been registered in the clinicaltrials.gov-register (number: NCT01857856)., (© 2021. The Author(s).)

Heart failure (HF) with mid-range or preserved ejection fraction (HFmrEF; HFpEF) is a heterogeneous disorder that could benefit from strategies to identify subpopulations at increased risk. We tested the hypothesis that HFmrEF and HFpEF patients with myocardial scars detected with late gadolinium enhancement (LGE) are at increased risk for all-cause mortality. Symptomatic HF patients with left ventricular ejection fraction (LVEF) > 40%, who underwent cardiac magnetic resonance (CMR) imaging were included. The presence of myocardial LGE lesions was visually assessed. T1 mapping was performed to calculate extracellular volume (ECV). Multivariable logistic regression analyses were used to determine associations between clinical characteristics and LGE. Cox regression analyses were used to assess the association between LGE and all-cause mortality. A total of 110 consecutive patients were included (mean age 71 ± 10 years, 49% women, median N-terminal brain natriuretic peptide (NT-proBNP) 1259 pg/ml). LGE lesions were detected in 37 (34%) patients. Previous myocardial infarction and increased LV mass index were strong and independent predictors for the presence of LGE (odds ratio 6.32, 95% confidence interval (CI) 2.07-19.31, p = 0.001 and 1.68 (1.03-2.73), p = 0.04, respectively). ECV was increased in patients with LGE lesions compared to those without (28.6 vs. 26.6%, p = 0.04). The presence of LGE lesions was associated with a fivefold increase in the incidence of all-cause mortality (hazards ratio 5.3, CI 1.5-18.1, p = 0.009), independent of age, sex, New York Heart Association (NYHA) functional class, NT-proBNP, LGE mass and LVEF. Myocardial scarring on CMR is associated with increased mortality in HF patients with LVEF > 40% and may aid in selecting a subpopulation at increased risk., (© 2021. The Author(s).)

Impaired exercise capacity is the key symptom of heart failure (HF) and is associated with reduced quality of life and higher mortality rates. Unfortunately, current therapies, although generally lifesaving, have only small or marginal effects on exercise capacity. Specific strategies to alleviate exercise intolerance may improve quality of life, while possibly improving prognosis as well. There is overwhelming evidence that physical exercise improves performance in cardiac and skeletal muscles in health and disease. Unravelling the mechanistic underpinnings of exercise-induced improvements in muscle function could provide targets that will allow us to boost exercise performance in HF. With the current review we discuss: (i) recently discovered signalling pathways that govern physiological muscle growth as well as mitochondrial quality control mechanisms that underlie metabolic adaptations to exercise; (ii) the mechanistic underpinnings of exercise intolerance in HF and the benefits of exercise in HF patients on molecular, functional and prognostic levels; and (iii) potential molecular therapeutics to improve exercise performance in HF. We propose that novel molecular therapies to boost adaptive muscle growth and mitochondrial quality control in HF should always be combined with some form of exercise training., (© 2021 The Authors. European Journal of Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Sodium-glucose cotransporter-2 (SGLT2) inhibitors have emerged as powerful drugs that can be used to treat heart failure (HF) patients, both with preserved and reduced ejection fraction and in the presence or absence of type 2 diabetes. While the mechanisms underlying the salutary effects of SGLT2 inhibitors have not been fully elucidated, there is clear evidence for a beneficial metabolic effect of these drugs. In this review, we discuss the effects of SGLT2 inhibitors on cardiac energy provision secondary to ketone bodies, pathological ventricular remodeling, and inflammation in patients with HF. While the specific contribution of ketone bodies to the pleiotropic cardiovascular benefits of SGLT2 inhibitors requires further clarification, ketone bodies themselves may also be used as a therapy for HF., Competing Interests: Conflict of Interest: The authors have no conflicts of interest to declare., (Copyright © 2022 The Korean Society of Lipid and Atherosclerosis.)

Background: Nonalcoholic fatty liver disease (NAFLD) is increasingly prevalent, paralleling the obesity epidemic. Ketone bodies are produced in the liver, but it is currently uncertain whether circulating ketone bodies are increased in the context of NAFLD. We investigated the association between NAFLD and circulating ketone bodies and determined the extent to which NAFLD and circulating ketone bodies are associated with all-cause mortality., Methods: Plasma ketone bodies were measured by nuclear magnetic resonance spectroscopy in participants of the general population-based PREVEND study. A fatty liver index (FLI) ≥60 was regarded as a proxy of NAFLD. Associations of an elevated FLI and ketone bodies with all-cause mortality were investigated using Cox regression analyses., Results: The study included 6,297 participants aged 54 ± 12 years, of whom 1,970 (31%) had elevated FLI. Participants with elevated FLI had higher total ketone bodies (194 [153-259] vs 170 [133-243] µmol/L; P < .001) than participants without elevated FLI. During 7.9 [7.8-8.9] years of follow-up, 387 (6%) participants died. An elevated FLI was independently associated with an increased risk of mortality (HR: 1.34 [1.06-1.70]; P = .02). Higher total ketone bodies were also associated with an increased mortality risk (HR per doubling: 1.29 [1.12-1.49]; P < .001). Mediation analysis suggested that the association of elevated FLI with all-cause mortality was in part mediated by ketone bodies (proportion mediated: 10%, P < .001)., Conclusion: Circulating ketone bodies were increased in participants with suspected NAFLD. Both suspected NAFLD and higher circulating ketone bodies are associated with an increased risk of all-cause mortality., (© 2021 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)

Members of the fetal-gene-program may act as regulatory components to impede deleterious events occurring with cardiac remodeling, and constitute potential novel therapeutic heart failure (HF) targets. Mitochondrial energy derangements occur both during early fetal development and in patients with HF. Here we aim to elucidate the role of DIO2, a member of the fetal-gene-program, in pluripotent stem cell (PSC)-derived human cardiomyocytes and on mitochondrial dynamics and energetics, specifically. RNA sequencing and pathway enrichment analysis was performed on mouse cardiac tissue at different time points during development, adult age, and ischemia-induced HF. To determine the function of DIO2 in cardiomyocytes, a stable human hPSC-line with a DIO2 knockdown was made using a short harpin sequence. Firstly, we showed the selenoprotein, type II deiodinase (DIO2): the enzyme responsible for the tissue-specific conversion of inactive (T4) into active thyroid hormone (T3), to be a member of the fetal-gene-program. Secondly, silencing DIO2 resulted in an increased reactive oxygen species, impaired activation of the mitochondrial unfolded protein response, severely impaired mitochondrial respiration and reduced cellular viability. Microscopical 3D reconstruction of the mitochondrial network displayed substantial mitochondrial fragmentation. Summarizing, we identified DIO2 to be a member of the fetal-gene-program and as a key regulator of mitochondrial performance in human cardiomyocytes. Our results suggest a key position of human DIO2 as a regulator of mitochondrial function in human cardiomyocytes.

Background: Circulating ketone bodies (KBs) are increased in patients with heart failure (HF), corresponding with increased cardiac KB metabolism and HF severity. However, the role of circulating KBs in ischemia/reperfusion remains unknown., Objectives: This study sought to investigate longitudinal changes of KBs and their associations with functional outcomes in patients presenting with ST-segment elevation myocardial infarction (STEMI)., Methods: KBs were measured in 369 participants from a randomized trial on early metformin therapy after STEMI. Nonfasting plasma concentrations of KBs (β-hydroxybutyrate, acetoacetate, and acetone) were measured by nuclear magnetic resonance spectroscopy at presentation, at 24 hours, and after 4 months. Myocardial infarct size and left ventricular ejection fraction (LVEF) were determined by cardiac magnetic resonance imaging at 4 months. Associations of circulating KBs with infarct size and LVEF were determined using multivariable linear regression analyses., Results: Circulating KBs were high at presentation with STEMI (median total KBs: 520 μmol/L; interquartile range [IQR]: 315-997 μmol/L). At 24 hours after reperfusion, KBs were still high compared with levels at 4-month follow-up (206 μmol/L [IQR: 174-246] vs 166 μmol/L [IQR: 143-201], respectively; P < 0.001). Increased KB concentrations at 24 hours were independently associated with larger myocardial infarct size (total KBs, per 100 μmol/L: β = 1.56; 95% confidence interval: 0.29-2.83; P = 0.016) and lower LVEF (β = -1.78; 95% CI: (-3.17 to -0.39; P = 0.012)., Conclusions: Circulating KBs are increased in patients presenting with STEMI. Higher KBs at 24 hours are associated with functional outcomes after STEMI, which suggests a potential role for ketone metabolism in response to myocardial ischemia. (Metabolic Modulation With Metformin to Reduce Heart Failure After Acute Myocardial Infarction: Glycometabolic Intervention as Adjunct to Primary Coronary Intervention in ST Elevation Myocardial Infarction (GIPS-III): a Randomized Controlled Trial; NCT01217307)., Competing Interests: Funding Support and Author Disclosures The GIPS-III trial was supported by grant 95103007 from the Netherlands Organization for Health Research and Development (ZonMw), The Hague, the Netherlands. Dr Westenbrink was supported by The Netherlands Organisation for Scientific Research (NWO VENI, grant 016.176.147) and the Netherlands Heart Foundation Senior Clinical Scientist Grant (2019T064), The Hague, the Netherlands. Drs Garcia and Connelly are employees of LabCorp. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Accumulating evidence suggests that the failing heart reverts energy metabolism toward increased utilization of ketone bodies. Despite many discrepancies in the literature, evidence from both bench and clinical research demonstrates beneficial effects of ketone bodies in heart failure. Ketone bodies are readily oxidized by cardiomyocytes and can provide ancillary fuel for the energy-starved failing heart. In addition, ketone bodies may help to restore cardiac function by mitigating inflammation, oxidative stress, and cardiac remodeling. In this review, we hypothesize that a therapeutic approach intended to restore cardiac metabolism through ketone bodies could both refuel and 'repair' the failing heart., Competing Interests: Declaration of interests The UMCG, which employs Drs de Boer and Westenbrink, has received research grants and/or fees from AstraZeneca, Abbott, Boehringer Ingelheim, Cardior Pharmaceuticals GmbH, Ionis Pharmaceuticals, Inc., Novo Nordisk, and Roche. Dr de Boer received speaker fees from Abbott, AstraZeneca, Bayer, Novartis, and Roche., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Heart failure (HF) is considered to be a prothrombotic condition and it has been suggested that coagulation factors contribute to maladaptive cardiac remodelling via activation of the protease-activated receptor 1 (PAR1). We tested the hypothesis that anticoagulation with the factor Xa (FXa) inhibitor apixaban would ameliorate cardiac remodelling in rats with HF after myocardial infarction (MI)., Methods and Results: Male Sprague-Dawley rats were either subjected to permanent ligation of the left ascending coronary artery (MI) or sham surgery. The MI and sham animals were randomly allocated to treatment with placebo or apixaban in the chow (150 mg/kg/day), starting 2 weeks after surgery. Cardiac function was assessed using echocardiography and histological and molecular markers of cardiac hypertrophy were assessed in the left ventricle (LV). Apixaban resulted in a fivefold increase in anti-FXa activity compared with vehicle, but no overt bleeding was observed and haematocrit levels remained similar in apixaban- and vehicle-treated groups. After 10 weeks of treatment, LV ejection fraction was 42 ± 3% in the MI group treated with apixaban and 37 ± 2 in the vehicle-treated MI group (p > 0.05). Both vehicle- and apixaban-treated MI groups also displayed similar degrees of LV dilatation, LV hypertrophy and interstitial fibrosis. Histological and molecular markers for pathological remodelling were also comparable between groups, as was the activity of signalling pathways downstream of the PAR1 receptor., Conclusion: FXa inhibition with apixaban does not influence pathological cardiac remodelling after MI. These data do not support the use of FXa inhibitor in HF patients with the aim to amend the severity of HF. Graphical Abstract., (© 2020. The Author(s).)

Aims: Two key echocardiographic parameters that are currently used to diagnose heart failure (HF) with preserved ejection fraction (HFpEF) are left atrial volume index (LAVi) and left ventricular mass index (LVMi). We investigated whether patients' characteristics, biomarkers, and co-morbidities are associated with these parameters and whether the relationships differ between patients with HFpEF or HF with reduced ejection fraction (HFrEF)., Methods: We consecutively enrolled 831 outpatients with typical signs and symptoms of HF and elevated N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels and categorized patients based upon left ventricular ejection fraction (LVEF): LVEF < 40% (HFrEF), LVEF between 40% and 50% (HF with mid-range ejection fraction), and LVEF ≥ 50% (HFpEF). The study includes consecutively enrolled HF patients from an HF outpatient clinic at a tertiary medical centre in the Netherlands. All patients underwent baseline characterization, laboratory measurements, and echocardiography., Results: Four hundred sixty-nine patients had HFrEF, 189 HF with mid-range ejection fraction, and 173 HFpEF. The patients with HFrEF were rather male [HFrEF: 323 (69%); HFpEF: 80 (46%); P < 0.001], and the age was comparable (HFrEF 67 ± 13; HFpEF 70 ± 14; P = 0.069). In HFpEF, more patients had hypertension [190 (40.5%); 114 (65.9%); P < 0.001], higher body mass indices (27 ± 8; 30 ± 7; P < 0.001), and atrial fibrillation [194 (41.4); 86 (49.7); P = 0.029]. The correlation analyses showed that in HFrEF patients, LAVi was significantly associated with age (β 0.293; P < 0.001), male gender (β 0.104; P = 0.042), body mass index (β -0160; P = 0.002), diastolic blood pressure (β -0.136; P < 0.001), New York Heart Association (β 0.174; P = 0.001), atrial fibrillation (β 0.381; P < 0.001), galectin 3 (β 0.230; P < 0.001), NT-proBNP (β 0.183; P < 0.001), estimated glomerular filtration rate (β -0.205; P < 0.001), LVEF (β -0.173; P = 0.001), and LVMi (β 0.337; P < 0.001). In HFpEF patients, only age (β 0.326; P < 0.001), atrial fibrillation (β 0.386; P < 0.001), NT-proBNP (β 0.176; P = 0.036), and LVMi (β 0.213; P = 0.013) were associated with LAVi., Conclusions: Although LVMi and LAVi are hallmark parameters to diagnose HFpEF, they only correlate with a few characteristics of HF and mainly with atrial fibrillation. In contrast, in HFrEF patients, LAVi relates strongly to several other HF parameters. These findings underscore the complexity in visualizing the pathophysiology of HFpEF and question the relation between cardiac structural remodeling and the impact of co-morbidities., (© 2021 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of European Society of Cardiology.)

Erythropoietin (EPO) is a haematopoietic hormone that regulates erythropoiesis, but the EPO-receptor (EpoR) is also expressed in non-haematopoietic tissues. Stimulation of the EpoR in cardiac and skeletal muscle provides protection from various forms of pathological stress, but its relevance for normal muscle physiology remains unclear. We aimed to determine the contribution of the tissue-specific EpoR to exercise-induced remodelling of cardiac and skeletal muscle. Baseline phenotyping was performed on left ventricle and m. gastrocnemius of mice that only express the EpoR in haematopoietic tissues (EpoR-tKO). Subsequently, mice were caged in the presence or absence of a running wheel for 4 weeks and exercise performance, cardiac function and histological and molecular markers for physiological adaptation were assessed. While gross morphology of both muscles was normal in EpoR-tKO mice, mitochondrial content in skeletal muscle was decreased by 50%, associated with similar reductions in mitochondrial biogenesis, while mitophagy was unaltered. When subjected to exercise, EpoR-tKO mice ran slower and covered less distance than wild-type (WT) mice (5.5 ± 0.6 vs. 8.0 ± 0.4 km/day, p < 0.01). The impaired exercise performance was paralleled by reductions in myocyte growth and angiogenesis in both muscle types. Our findings indicate that the endogenous EPO-EpoR system controls mitochondrial biogenesis in skeletal muscle. The reductions in mitochondrial content were associated with reduced exercise capacity in response to voluntary exercise, supporting a critical role for the extra-haematopoietic EpoR in exercise performance., (© 2021. The Author(s).)

Aims: Heart failure with preserved ejection fraction (HFpEF) is a multifactorial disease that constitutes several distinct phenotypes, including a common cardiometabolic phenotype with obesity and type 2 diabetes mellitus. Treatment options for HFpEF are limited, and development of novel therapeutics is hindered by the paucity of suitable preclinical HFpEF models that recapitulate the complexity of human HFpEF. Metabolic drugs, like glucagon-like peptide receptor agonist (GLP-1 RA) and sodium-glucose co-transporter 2 inhibitors (SGLT2i), have emerged as promising drugs to restore metabolic perturbations and may have value in the treatment of the cardiometabolic HFpEF phenotype. We aimed to develop a multifactorial HFpEF mouse model that closely resembles the cardiometabolic HFpEF phenotype, and evaluated the GLP-1 RA liraglutide (Lira) and the SGLT2i dapagliflozin (Dapa)., Methods and Results: Aged (18-22 months old) female C57BL/6J mice were fed a standardized chow (CTRL) or high-fat diet (HFD) for 12 weeks. After 8 weeks HFD, angiotensin II (ANGII), was administered for 4 weeks via osmotic mini pumps. HFD + ANGII resulted in a cardiometabolic HFpEF phenotype, including obesity, impaired glucose handling, and metabolic dysregulation with inflammation. The multiple hit resulted in typical clinical HFpEF features, including cardiac hypertrophy and fibrosis with preserved fractional shortening but with impaired myocardial deformation, atrial enlargement, lung congestion, and elevated blood pressures. Treatment with Lira attenuated the cardiometabolic dysregulation and improved cardiac function, with reduced cardiac hypertrophy, less myocardial fibrosis, and attenuation of atrial weight, natriuretic peptide levels, and lung congestion. Dapa treatment improved glucose handling, but had mild effects on the HFpEF phenotype., Conclusions: We developed a mouse model that recapitulates the human HFpEF disease, providing a novel opportunity to study disease pathogenesis and the development of enhanced therapeutic approaches. We furthermore show that attenuation of cardiometabolic dysregulation may represent a novel therapeutic target for the treatment of HFpEF., (© The Author(s) 2020. Published by Oxford University Press on behalf of the European Society of Cardiology.)

The start codon c.1A>G mutation in KLHL24, encoding ubiquitin-ligase KLHL24, results in the loss of 28 N-terminal amino acids (KLHL24-ΔN28) by skipping the initial start codon. In skin, KLHL24-ΔN28 leads to gain of function, excessively targeting intermediate filament keratin-14 for proteasomal degradation, ultimately causing epidermolysis bullosa simplex (EBS). The majority of these EBS-patients are also diagnosed with dilated cardiomyopathy (DCM), but the pathological mechanism in the heart is unknown. As desmin is the cardiac homologue of keratin-14, we hypothesized that KLHL24-ΔN28 leads to excessive degradation of desmin, resulting in DCM. Dynamically loaded engineered heart tissues (dyn-EHTs) were generated from human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes from two patients and three (non)familial controls. Ten-fold lower desmin protein levels were observed in patient-derived dyn-EHTs, in line with diminished desmin levels detected in patients' explanted heart. This was accompanied by tissue dilatation, impaired mitochondrial function, decreased force values and increased cardiomyocyte stress. HEK293 transfection studies confirmed KLHL24-mediated desmin degradation. KLHL24 RNA interference or direct desmin overexpression recovered desmin protein levels, restoring morphology and function in patient-derived dyn-EHTs. To conclude, presence of KLHL24-ΔN28 in cardiomyocytes leads to excessive degradation of desmin, affecting tissue morphology and function, that can be prevented by restoring desmin protein levels.

Objective: Recent studies have reported suboptimal up-titration of heart failure (HF) therapies in patients with heart failure and a reduced ejection fraction (HFrEF). Here, we report on the achieved doses after nurse-led up-titration, reasons for not achieving the target dose, subsequent changes in left ventricular ejection fraction (LVEF), and mortality., Methods: From 2012 to 2018, 378 HFrEF patients with a recent (< 3 months) diagnosis of HF were referred to a specialised HF-nurse led clinic for protocolised up-titration of guideline-directed medical therapy (GDMT). The achieved doses of GDMT at 9 months were recorded, as well as reasons for not achieving the optimal dose in all patients. Echocardiography was performed at baseline and after up-titration in 278 patients., Results: Of 345 HFrEF patients with a follow-up visit after 9 months, 69% reached ≥ 50% of the recommended dose of renin-angiotensin-system (RAS) inhibitors, 73% reached ≥ 50% of the recommended dose of beta-blockers and 77% reached ≥ 50% of the recommended dose of mineralocorticoid receptor antagonists. The main reasons for not reaching the target dose were hypotension (RAS inhibitors and beta-blockers), bradycardia (beta-blockers) and renal dysfunction (RAS inhibitors). During a median follow-up of 9 months, mean LVEF increased from 27.6% at baseline to 38.8% at follow-up. Each 5% increase in LVEF was associated with an adjusted hazard ratio of 0.84 (0.75-0.94, p = 0.002) for mortality and 0.85 (0.78-0.94, p = 0.001) for the combined endpoint of mortality and/or HF hospitalisation after a mean follow-up of 3.3 years., Conclusions: This study shows that protocolised up-titration in a nurse-led HF clinic leads to high doses of GDMT and improvement of LVEF in patients with new-onset HFrEF., (© 2021. The Author(s).)

Background: Epicardial adipose tissue (EAT) has been implicated in the pathophysiology of heart failure (HF) with left ventricular ejection fraction (LVEF) >40%, but whether this is due to a regional or global effect of EAT remains unclear., Hypothesis: Regional EAT is associated with alterations in local cardiac structure and function., Methods: Patients with HF and LVEF >40% were studied. Cardiac Magnetic Resonance imaging was used to localize EAT surrounding the right ventricle (RV) and LV separately, using anterior- and posterior interventricular grooves as boundaries. Atrial- and ventricular EAT were differentiated using the mitral-valve position. All EAT depots were related to the adjacent myocardial structure., Results: 102 consecutive HF patients were enrolled. The majority of EAT was present around the RV (42% of total EAT, p < .001). RV-EAT showed a strong association with increased RV mass (β = 0.60, p < .001) and remained associated with RV mass after adjusting for total EAT, sex, N-terminal prohormone of brain natriuretic peptide (NT-proBNP), renal function and blood glucose. LV-EAT showed a similar association with LV mass in univariable analysis, albeit less pronounced (β = 0.24, p = .02). Atrial EAT was increased in patients with atrial fibrillation compared to those without atrial fibrillation (30 vs. 26 ml/m 2 , p = .04), whereas ventricular EAT was similar (74 vs. 75 ml/m 2 , p = .9)., Conclusions: Regional EAT is strongly associated with local cardiac structure and function in HF patients with LVEF >40%. These data support the hypothesis that regional EAT is involved in the pathophysiology of HF with LVEF >40%., (© 2021 The Authors. Clinical Cardiology published by Wiley Periodicals LLC.)

Background: In the failing heart, energy metabolism is shifted towards increased ketone body oxidation. Nevertheless, the association of beta-hydroxybutyrate (β-OHB) with development of heart failure (HF) remains unclear. We investigated the association between plasma β-OHB and the risk of HF in a prospective population-based cohort., Design: Plasma β-OHB concentrations were measured in 6134 participants of the PREVEND study. Risk of incident HF with reduced (HFrEF) or preserved (HFpEF) ejection fraction was estimated using multivariable-adjusted Cox regression models., Results: During median follow-up for 8.2 years, 227 subjects were diagnosed with HF (137 with HFrEF; 90 with HFpEF). Cox regression analyses revealed a significant association of higher β-OHB concentrations with incident HF (HR per 1 standard deviation increase, 1.40 (95% CI: 1.21-1.63; P < .001), which was largely attributable to HFrEF. In women, the hazard ratio (HR) for HFrEF per 1 standard deviation increase in β-OHB was 1.73 (95% confidence interval (CI): 1.17-2.56, P = .005) in age, BMI, type 2 diabetes, hypertension, myocardial infarction, smoking, alcohol consumption, total cholesterol, HDL-C, triglycerides, glucose, eGFR and UAE adjusted analysis. In men, in the same fully adjusted analysis, the HR was 1.14 (CI: 0.86-1.53, P = .36) (P < .01 for sex interaction). In N-terminal pro-brain natriuretic peptide (NT-proBNP)-stratified analysis, the age-adjusted association with HF was significant in women with higher NT-proBNP levels (P = .008)., Conclusions: This prospective study suggests that high plasma concentrations of β-OHB are associated with an increased risk of HFrEF, particularly in women. The mechanisms responsible for the sex differences of this association warrant further study., (© 2020 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)

ATPase inhibitory factor-1 (IF1) preserves cellular ATP under conditions of respiratory collapse, yet the function of IF1 under normal respiring conditions is unresolved. We tested the hypothesis that IF1 promotes mitochondrial dysfunction and pathological cardiomyocyte hypertrophy in the context of heart failure (HF). Methods and results: Cardiac expression of IF1 was increased in mice and in humans with HF, downstream of neurohumoral signaling pathways and in patterns that resembled the fetal-like gene program. Adenoviral expression of wild-type IF1 in primary cardiomyocytes resulted in pathological hypertrophy and metabolic remodeling as evidenced by enhanced mitochondrial oxidative stress, reduced mitochondrial respiratory capacity, and the augmentation of extramitochondrial glycolysis. Similar perturbations were observed with an IF1 mutant incapable of binding to ATP synthase (E55A mutation), an indication that these effects occurred independent of binding to ATP synthase. Instead, IF1 promoted mitochondrial fragmentation and compromised mitochondrial Ca 2+ handling, which resulted in sarcoplasmic reticulum Ca 2+ overloading. The effects of IF1 on Ca 2+ handling were associated with the cytosolic activation of calcium-calmodulin kinase II (CaMKII) and inhibition of CaMKII or co-expression of catalytically dead CaMKIIδC was sufficient to prevent IF1 induced pathological hypertrophy. Conclusions: IF1 represents a novel member of the fetal-like gene program that contributes to mitochondrial dysfunction and pathological cardiac remodeling in HF. Furthermore, we present evidence for a novel, ATP-synthase-independent, role for IF1 in mitochondrial Ca 2+ handling and mitochondrial-to-nuclear crosstalk involving CaMKII.

Metabolic perturbations underlie a variety of cardiovascular disease states; yet, metabolic interventions to prevent or treat these disorders are sparse. Ketones carry a negative clinical stigma as they are involved in diabetic ketoacidosis. However, evidence from both experimental and clinical research has uncovered a protective role for ketones in cardiovascular disease. Although ketones may provide supplemental fuel for the energy-starved heart, their cardiovascular effects appear to extend far beyond cardiac energetics. Indeed, ketone bodies have been shown to influence a variety of cellular processes including gene transcription, inflammation and oxidative stress, endothelial function, cardiac remodeling, and cardiovascular risk factors. This paper reviews the bioenergetic and pleiotropic effects of ketone bodies that could potentially contribute to its cardiovascular benefits based on evidence from animal and human studies., Competing Interests: Funding Support and Author Disclosures The UMCG, which employs Drs. Yurista, de Boer, and Westenbrink, has received research grants and/or fees from Abbott, AstraZeneca, Bristol Myers Squibb, Novartis, Novo Nordisk, and Roche. Dr. Chong is supported by a fellowship jointly awarded by the National Health & Medical Research Council (GNT1162356) and National Heart Foundation of Australia (102126). Dr. Kelly is supported by NIH R01 HL058493, HL128349, and HL151345; and has served as a scientific consultant for Pfizer, Amgen, and Janssen. Dr. de Boer is supported by the Netherlands Heart Foundation (CVON DOUBLE DOSE, grant 2020-8005, CVON SHE-PREDICTS-HF, grant 2017-21, and CVON RED-CVD, grant 2017-11) and the European Research Council (ERC CoG 818715, SECRETE-HF); and has received personal fees from Abbott, AstraZeneca, Novartis, and Roche. Dr. Westenbrink is supported by the Netherlands Organisation for Scientific Research (NWO VENI, grant 016.176.147) and the Netherlands Heart Foundation Senior Clinical Scientist Grant (2019T064) and CVON DOUBLE DOSE (grant 2020-8005). All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Testosterone regulates nutrient and energy balance to maintain protein synthesis and metabolism in cardiomyocytes, but supraphysiological concentrations induce cardiac hypertrophy. Previously, we determined that testosterone increased glucose uptake-via AMP-activated protein kinase (AMPK)-after acute treatment in cardiomyocytes. However, whether elevated glucose uptake is involved in long-term changes of glucose metabolism or is required during cardiomyocyte growth remained unknown. In this study, we hypothesized that glucose uptake and glycolysis increase in testosterone-treated cardiomyocytes through AMPK and androgen receptor (AR)., Methods: Cultured cardiomyocytes were stimulated with 100 nM testosterone for 24 h, and hypertrophy was verified by increased cell size and mRNA levels of β-myosin heavy chain (β-mhc). Glucose uptake was assessed by 2-NBDG. Glycolysis and glycolytic capacity were determined by measuring extracellular acidification rate (ECAR)., Results: Testosterone induced cardiomyocyte hypertrophy that was accompanied by increased glucose uptake, glycolysis enhancement and upregulated mRNA expression of hexokinase 2. In addition, testosterone increased AMPK phosphorylation (Thr172), while inhibition of both AMPK and AR blocked glycolysis and cardiomyocyte hypertrophy induced by testosterone. Moreover, testosterone supplementation in adult male rats by 5 weeks induced cardiac hypertrophy and upregulated β-mhc, Hk2 and Pfk2 mRNA levels., Conclusion: These results indicate that testosterone stimulates glucose metabolism by activation of AMPK and AR signaling which are critical to induce cardiomyocyte hypertrophy.