Empagliflozin cardiac benefits in the EMPA-REG OUTCOME (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) trial cannot be explained exclusively by its ...antihyperglycemic activity.
The hypothesis was that empagliflozin’s cardiac benefits are mediated by switching myocardial fuel metabolism away from glucose toward ketone bodies (KB), which improves myocardial energy production.
Heart failure was induced in nondiabetic pigs (n = 14) by 2-h balloon occlusion of the proximal left anterior descending artery. Animals were randomized to empagliflozin or placebo for 2 months. Animals were evaluated with cardiac magnetic resonance imaging and 3-dimensional echocardiography. Myocardial metabolite consumption was analyzed by simultaneous blood sampling from coronary artery and coronary sinus. Myocardial samples were obtained for molecular evaluation. Nonmyocardial infarction animals served as comparison.
Despite similar initial ischemic myocardial injury in both groups, the empagliflozin group showed amelioration of adverse remodeling at 2 months (lower left ventricular LV mass, reduced LV dilatation, less LV sphericity) versus the control group. LV systolic function (LV ejection fraction and echocardiography-derived strains) was improved, as was neurohormonal activation. Compared with nonmyocardial infarction, control animals increased myocardial glucose consumption mainly through anaerobic glycolysis while reducing utilization of free fatty acid (FFA) and branched-chain amino acid (BCAA). Empagliflozin-treated pigs did not consume glucose (reduction in myocardial glucose uptake, and glucose-related enzymes) but instead switched toward utilization of KB, FFA, and BCAA (increased myocardial uptake of these 3 metabolites, and enhanced expression/activity of the enzymes implicated in the metabolism of KB/FFA/BCAA). Empagliflozin increased myocardial ATP content and enhanced myocardial work efficiency.
Empagliflozin ameliorates adverse cardiac remodeling and heart failure in a nondiabetic porcine model. Empagliflozin switches myocardial fuel utilization away from glucose toward KB, FFA, and BCAA, thereby improving myocardial energetics, enhancing LV systolic function, and ameliorating adverse LV remodeling.
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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.
Large clinical trials established the benefits of sodium-glucose cotransporter 2 inhibitors in patients with diabetes and with heart failure with reduced ejection fraction (HFrEF). The early and ...significant improvement in clinical outcomes is likely explained by effects beyond a reduction in hyperglycemia.
The purpose of this study was to assess the effect of empagliflozin on left ventricular (LV) function and volumes, functional capacity, and quality of life (QoL) in nondiabetic HFrEF patients.
In this double-blind, placebo-controlled trial, nondiabetic HFrEF patients (n = 84) were randomized to empagliflozin 10 mg daily or placebo for 6 months. The primary endpoint was change in LV end-diastolic and -systolic volume assessed by cardiac magnetic resonance. Secondary endpoints included changes in LV mass, LV ejection fraction, peak oxygen consumption in the cardiopulmonary exercise test, 6-min walk test, and quality of life.
Empagliflozin was associated with a significant reduction of LV end-diastolic volume (−25.1 ± 26.0 ml vs. −1.5 ± 25.4 ml for empagliflozin vs. placebo, respectively; p < 0.001) and LV end-systolic volume (−26.6 ± 20.5 ml vs. −0.5 ± 21.9 ml for empagliflozin vs. placebo; p < 0.001). Empagliflozin was associated with reductions in LV mass (−17.8 ± 31.9 g vs. 4.1 ± 13.4 g, for empagliflozin vs. placebo, respectively; p < 0.001) and LV sphericity, and improvements in LV ejection fraction (6.0 ± 4.2 vs. −0.1 ± 3.9; p < 0.001). Patients who received empagliflozin had significant improvements in peak O2 consumption (1.1 ± 2.6 ml/min/kg vs. −0.5 ± 1.9 ml/min/kg for empagliflozin vs. placebo, respectively; p = 0.017), oxygen uptake efficiency slope (111 ± 267 vs. −145 ± 318; p < 0.001), as well as in 6-min walk test (81 ± 64 m vs. −35 ± 68 m; p < 0.001) and quality of life (Kansas City Cardiomyopathy Questionnaire-12: 21 ± 18 vs. 2 ± 15; p < 0.001).
Empagliflozin administration to nondiabetic HFrEF patients significantly improves LV volumes, LV mass, LV systolic function, functional capacity, and quality of life when compared with placebo. Our observations strongly support a role for sodium-glucose cotransporter 2 inhibitors in the treatment of HFrEF patients independently of their glycemic status. (Are the “Cardiac Benefits” of Empagliflozin Independent of Its Hypoglycemic Activity? ATRU-4 EMPA-TROPISM; NCT03485222)
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SGLT2i (sodium-glucose cotransporter-2 inhibitors) improve clinical outcomes in patients with heart failure, but the mechanisms of action are not completely understood. SGLT2i increases circulating ...levels of ketone bodies, which has been demonstrated to enhance myocardial energetics and induce reverse ventricular remodeling. However, the role of SGLT2i or ketone bodies on myocardial ischemia reperfusion injury remains in the dark. The objective of this study is to investigate the cardioprotective potential of empagliflozin and ketone bodies during acute myocardial infarction (MI).
We used a nondiabetic porcine model of ischemia reperfusion using a percutaneous occlusion of proximal left anterior descending artery for 45 minutes. Animals received 1-week pretreatment with either empagliflozin or placebo prior to MI induction. Additionally, a third group received intravenous infusion of the ketone body BOHB (beta-hydroxybutyrate) during the MI induction. Acute effects of the treatments were assessed 4-hour post-MI by cardiac magnetic resonance and histology (thioflavin for area at risk, triphenyltetrazolium chloride staining for MI size). All animals were euthanized immediately postcardiac magnetic resonance, and heart samples were collected.
The area at risk was similar in all groups. Empagliflozin treatment increased BOHB levels. Empagliflozin-treated animals showed significantly higher myocardial salvage, smaller MI size (both by cardiac magnetic resonance and histology), less microvascular obstruction, and improved cardiac function (left ventricle ejection fraction and strain). Furthermore, empagliflozin-treated animals demonstrated reduced biomarkers of cardiomyocyte apoptosis and oxidative stress compared with placebo. The BOHB group showed similar results to the empagliflozin group.
One-week pretreatment with empagliflozin ameliorates ischemia reperfusion injury, reduces MI size and microvascular obstruction, increases myocardial salvage, preserves left ventricle systolic function, and lowers apoptosis and oxidative stress. Periprocedural intravenous infusion of BOHB during myocardial ischemia also induces cardioprotection, suggesting a role for BOHB availability as an additional mechanism within the wide spectrum of actions of SGLT2i.
The sodium-glucose cotransporter (SGLT) inhibitors represent a new alternative for treating patients with diabetes mellitus. They act primarily by inhibiting glucose reabsorption in the renal tubule ...and therefore, decreasing blood glucose levels. While little is yet known about SGLT subtype 1, SGLT2 inhibitors have demonstrated to significantly reduce cardiovascular mortality and heart failure hospitalizations. This cardioprotective benefit seems to be independent of their glucose-lowering properties; however, the underlying mechanism(s) remains still unclear and numerous hypotheses have been postulated to date. Moreover, preclinical research has suggested an important role of SGLT1 receptors on myocardial ischemia. Following acute phase of cardiac injury there is an increased activity of SGLT1 cotransport that ensures adequate energy supply to the cardiac cells. Nonetheless, a long-term upregulation of this receptor may not be that beneficial and whether its inhibition is positive or not should be further addressed. This review aims to present the most cutting-edge insights into SGLT receptors.
The purpose of this study was to investigate the effect of empagliflozin on diastolic function in a nondiabetic heart failure with reduced ejection fraction (HFrEF) scenario and on the pathways ...causing diastolic dysfunction.
This group demonstrated that empagliflozin ameliorates adverse cardiac remodeling, enhances myocardial energetics, and improves left ventricular systolic function in a nondiabetic porcine model of HF. Whether empagliflozin also improves diastolic function remains unknown. Hypothetically, empagliflozin would improve diastolic function in HF mediated both by a reduction in interstitial myocardial fibrosis and an improvement in cardiomyocyte stiffness (titin phosphorylation).
HF was induced in nondiabetic pigs by 2-h balloon occlusion of proximal left anterior descending artery. Animals were randomized to empagliflozin or placebo for 2 months. Cardiac function was evaluated with cardiac magnetic resonance (CMR), 3-dimensional echocardiography, and invasive hemodynamics. In vitro relaxation of cardiomyocytes was studied in primary culture. Myocardial samples were obtained for histological and molecular evaluation. Myocardial metabolite consumption was analyzed by simultaneous blood sampling from coronary artery and coronary sinus.
Despite similar initial ischemic myocardial injury, the empagliflozin group showed significantly improved diastolic function at 2 months, assessed by conventional echocardiography (higher e' and color M-mode propagation velocity, lower E/e' ratio, myocardial performance Tei index, isovolumic relaxation time, and left atrial size), echocardiography-derived strain imaging (strain imaging diastolic index, strain rate at isovolumic relaxation time and during early diastole, and untwisting), and CMR (higher peak filling rate, larger first filling volume). Invasive hemodynamics confirmed improved diastolic function with empagliflozin (better peak LV pressure rate of decay (-dP/dt), shorter Tau, lower end-diastolic pressure-volume relationship (EDPVR), and reduced filling pressures). Empagliflozin reduced interstitial myocardial fibrosis at the imaging, histological and molecular level. Empagliflozin improved nitric oxide signaling (endothelial nitric oxide synthetase eNOS activity, nitric oxide NO availability, cyclic guanosine monophosphate (cGMP) content, protein kinase G PKG signaling) and enhanced titin phosphorylation (which is responsible for cardiomyocyte stiffness). Indeed, isolated cardiomyocytes exhibited better relaxation in empagliflozin-treated animals. Myocardial consumption of glucose and ketone bodies negatively and positively correlated with diastolic function, respectively.
Empagliflozin ameliorates diastolic function in a nondiabetic HF porcine model, mitigates histological and molecular remodeling, and reduces both left ventricle and cardiomyocyte stiffness.
Cardiac metabolism represents a complex network of numerous pathways responsible for an adequate supply of ATP to the incessant contractile apparatus. Impairments of such pathways are associated with ...myocardial dysfunction. The newest antidiabetic drugs, the SGLT2 inhibitors, have been demonstrated to reduce cardiovascular mortality and heart failure hospitalizations. The mechanisms underlying these benefits are still uncertain; however, they may play a decisive role in restoring energy efficiency to the damaged heart. Areas covered: This article reviews normal cardiac metabolism and contribution of different substrates to fuel supply. Specific attention is devoted to alterations of these pathways and their association with myocardial dysfunction. In addition, the impact of the novel SGLT2 inhibitors on cardiac mortality and heart failure hospitalizations is discussed. Various postulated mechanisms responsible for such benefits are also discussed. Expert opinion: Metabolic alterations seem to play a crucial role in etiology and progression of heart failure. The cardiovascular benefits of the novel SGLT2 inhibitors have attracted more attention to this field. With effects beyond lowering glucose levels, these agents have been reported to induce changes in cardiac metabolism and to exert anti-inflammatory properties that may contribute to their large cardiovascular beneficial effects by improving contractile bioenergetics. Therefore, SGLT2 inhibitors may become an alternative drug to treat heart failure patients, regardless of diabetic status.
Beginning to understand high-density lipoproteins Santos-Gallego, Carlos G; Badimon, Juan J; Rosenson, Robert S
Endocrinology and metabolism clinics of North America,
12/2014, Letnik:
43, Številka:
4
Journal Article
Recenzirano
This article reconciles the classic view of high-density lipoproteins (HDL) associated with low risk for cardiovascular disease (CVD) with recent data (genetics studies and randomized clinical ...trials) casting doubt over the widely accepted beneficial role of HDL regarding CVD risk. Although HDL cholesterol has been used as a surrogate measure to investigate HDL function, the cholesterol content in HDL particles is not an indicator of the atheroprotective properties of HDL. Thus, more precise measures of HDL metabolism are needed to reflect and account for the beneficial effects of HDL particles. Current and emerging therapies targeting HDL are discussed.
Mediterranean and low-fat diets are effective in the primary prevention of cardiovascular disease. We did a long-term randomised trial to compare the effects of these two diets in secondary ...prevention of cardiovascular disease.
The CORDIOPREV study was a single-centre, randomised clinical trial done at the Reina Sofia University Hospital in Córdoba, Spain. Patients with established coronary heart disease (aged 20–75 years) were randomly assigned in a 1:1 ratio by the Andalusian School of Public Health to receive a Mediterranean diet or a low-fat diet intervention, with a follow-up of 7 years. Clinical investigators (physicians, investigators, and clinical endpoint committee members) were masked to treatment assignment; participants were not. A team of dietitians did the dietary interventions. The primary outcome (assessed by intention to treat) was a composite of major cardiovascular events, including myocardial infarction, revascularisation, ischaemic stroke, peripheral artery disease, and cardiovascular death. This study is registered with ClinicalTrials.gov, NCT00924937.
From Oct 1, 2009, to Feb 28, 2012, a total of 1002 patients were enrolled, 500 (49·9%) in the low-fat diet group and 502 (50·1%) in the Mediterranean diet group. The mean age was 59·5 years (SD 8·7) and 827 (82·5%) of 1002 patients were men. The primary endpoint occurred in 198 participants: 87 in the Mediterranean diet group and 111 in the low-fat group (crude rate per 1000 person-years: 28·1 95% CI 27·9–28·3 in the Mediterranean diet group vs 37·7 37·5–37·9 in the low-fat group, log-rank p=0·039). Multivariable-adjusted hazard ratios (HRs) of the different models ranged from 0·719 (95% CI 0·541–0·957) to 0·753 (0·568–0·998) in favour of the Mediterranean diet. These effects were more evident in men, with primary endpoints occurring in 67 (16·2%) of 414 men in the Mediterranean diet group versus 94 (22·8%) of 413 men in the low-fat diet group (multiadjusted HR 0·669 95% CI 0·489–0·915, log-rank p=0·013), than in 175 women for whom no difference was found between groups.
In secondary prevention, the Mediterranean diet was superior to the low-fat diet in preventing major cardiovascular events. Our results are relevant to clinical practice, supporting the use of the Mediterranean diet in secondary prevention.
Fundacion Patrimonio Comunal Olivarero; Fundacion Centro para la Excelencia en Investigacion sobre Aceite de Oliva y Salud; local, regional, and national Spanish Governments; European Union.
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