Effects of reducing blood pressure on renal outcomes in patients with type 2 diabetes: Focus on SGLT2 inhibitors and EMPA-REG OUTCOME

Empagliflozin, a sodium–glucose cotransporter type 2 (SGLT2) inhibitor, has enabled remarkable reductions in cardiovascular and all-cause mortality as well as in renal outcomes in patients with type 2 diabetes (T2D) and a history of cardiovascular disease in the EMPA-REG OUTCOME. These results have been attributed to haemodynamic rather than metabolic effects, in part due to the osmotic/diuretic action of empagliflozin and the reduction in arterial blood pressure (BP). The present narrative review includes the results of meta-analyses of trials evaluating the effects on renal outcomes of lowering BP in patients with T2D, with a special focus on the influence of baseline and achieved systolic BP, and compares the renal outcome results of the EMPA-REG OUTCOME with those of other major trials with inhibitors of the renin–angiotensin system in patients with T2D and the preliminary findings with other SGLT2 inhibitors, and also evaluates post hoc analyses from the EMPA-REG OUTCOME of special interest as regards the BP-lowering hypothesis and renal function. While systemic BP reduction associated to empagliflozin therapy may have contributed to the renal benefits reported in EMPA-REG OUTCOME, other local mechanisms related to kidney homoeostasis most probably also played a role in the overall protection observed in the trial.     

Association between uric acid levels and cardio-renal outcomes and death in patients with type 2 diabetes: A subanalysis of EMPA-REG OUTCOME

In the EMPA-REG OUTCOME trial, we explored the association between pre-randomization uric acid level tertile (<309.30 μmol/L; 309.30 to <387.21 μmol/L; ≥387.21 μmol/L) and cardiovascular (CV) death, hospitalization for heart failure (HHF), HHF or CV death, all-cause mortality, three-point major adverse CV events (MACE), and incident or worsening nephropathy. Patients with type 2 diabetes and CV disease received empagliflozin or placebo. The median baseline plasma uric acid level was 344.98 μmol/L, and patients’ baseline characteristics were mainly balanced across tertiles. Baseline uric acid levels were associated with cardio-renal outcomes: in the placebo group, for the highest versus lowest tertile, the multivariable hazard ratios for three-point MACE, HHF or CV death, and incident or worsening nephropathy were 1.22 (95% confidence interval [CI] 0.89–1.67; P = 0.2088), 1.51 (95% CI 1.02–2.23; P = 0.0396) and 1.77 (95% CI 1.33–2.34; P < 0.0001), respectively. When tested as a continuous variable, baseline uric acid was associated with all outcomes in the placebo group. Empagliflozin improved all cardio-renal outcomes across tertiles, with all interaction P values >0.05. Further investigation of these relationships is required.     

Empagliflozin in Heart Failure With Predicted Preserved Versus Reduced Ejection Fraction: Data From the EMPA-REG OUTCOME Trial

BackgroundIn the EMPA-REG OUTCOME trial, ejection fraction (EF) data were not collected. In the subpopulation with heart failure (HF), we applied a new predictive model for EF to determine the effects of empagliflozin in HF with predicted reduced (HFrEF) vs preserved (HFpEF) EF vs no HF.Methods and ResultsWe applied a validated EF predictive model based on patient baseline characteristics and treatments to categorize patients with HF as being likely to have HF with mid-range EF (HFmrEF)/HFrEF (EF <50%) or HFpEF (EF ≥50%). Cox regression was used to assess the effect of empagliflozin vs placebo on cardiovascular death/HF hospitalization (HHF), cardiovascular and all-cause mortality, and HHF in patients with predicted HFpEF, HFmrEF/HFrEF and no HF. Of 7001 EMPA-REG OUTCOME patients with data available for this analysis, 6314 (90%) had no history of HF. Of the 687 with history of HF, 479 (69.7%) were predicted to have HFmrEF/HFrEF and 208 (30.3%) to have HFpEF. Empagliflozin's treatment effect was consistent in predicted HFpEF, HFmrEF/HFrEF and no-HF for each outcome (HR [95% CI] for the primary outcome 0.60 [0.31–1.17], 0.79 [0.51–1.23], and 0.63 [0.50–0.78], respectively; P interaction = 0.62).ConclusionsIn EMPA-REG OUTCOME, one-third of the patients with HF had predicted HFpEF. The benefits of empagliflozin on HF and mortality outcomes were consistent in nonHF, predicted HFpEF and HFmrEF/HFrEF.     

Changes in cardiac and vascular haemodynamics as potential mediators of improvements in cardiovascular and kidney outcomes with empagliflozin in type 2 diabetes

AimsEvaluate changes in haemodynamic markers as mediators of cardiovascular (CV) and kidney benefits with empagliflozin.MethodsPost-hoc analysis of EMPA-REG OUTCOME in patients with type 2 diabetes (T2D) and established CV disease receiving empagliflozin (10 and 25 mg) or placebo. Outcomes were CV death, hospitalisation for heart failure [HF], HF death, incident/worsening nephropathy, new onset macroalbuminuria, and the composite of sustained estimated glomerular filtration rate decline ≥40 % from baseline, renal replacement therapy or renal death. To be considered a mediator, changes in variable (pulse pressure, mean arterial pressure and cardiac workload) over time had to be (1) affected by active treatment, (2) associated with the outcome, and (3) adjustment for changes over time must reduce treatment effect versus an unadjusted analysis. Variables were evaluated in Cox regression analyses.ResultsPulse pressure, mean arterial pressure and cardiac workload were significantly reduced by empagliflozin vs placebo. Using change from baseline to Week 12 or sensitivity analyses (time-dependent updated mean and current change from baseline) of these CV parameters, only small impacts on empagliflozin effect on CV and kidney outcomes were shown.ConclusionsImprovements in haemodynamic parameters did not substantially mediate empagliflozin benefits on CV and kidney outcomes in patients with T2DM and established CV disease.     

Impact of empagliflozin in patients with diabetes and heart failure

Heart failure (HF) is a common disease with increased risk for mortality and morbidity among patients with type 2 diabetes mellitus (T2DM). Optimal glycemic control in this patient population is challenging as many available therapies can potentially exacerbate symptoms of HF. Empagliflozin is one in a novel class of agents, the sodium glucose co-transporter 2 (SGLT2) inhibitors, that lowers blood glucose by increasing urinary glucose excretion and improves glycemic control and lowers body weight and blood pressure. In the recent EMPA-REG OUTCOME trial, empagliflozin was shown to improve cardiovascular outcomes in patients with T2DM and established cardiovascular risk where it reduced HF hospitalizations and cardiovascular death, with a consistent benefit among patients both with and without baseline HF. Here, we review the empagliflozin data on HF outcomes and discuss potential mechanisms for its benefits in HF with a focus on the potentially significant impact that empagliflozin may have on the care of patients with T2DM and HF in the future.     

Empagliflozin Ameliorates Diastolic Dysfunction and Left Ventricular Fibrosis/Stiffness in Nondiabetic Heart Failure: A Multimodality Study

ObjectivesThe 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.BackgroundThis 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).MethodsHF 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.ResultsDespite 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.ConclusionsEmpagliflozin ameliorates diastolic function in a nondiabetic HF porcine model, mitigates histological and molecular remodeling, and reduces both left ventricle and cardiomyocyte stiffness.     

Empagliflozin Ameliorates Adverse Left Ventricular Remodeling in Nondiabetic Heart Failure by Enhancing Myocardial Energetics

Background

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.

Empagliflozin Reduces Myocardial Extracellular Volume in Patients With Type 2 Diabetes and Coronary Artery Disease

ObjectivesThis study sought to evaluate the effects of empagliflozin on extracellular volume (ECV) in individuals with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD).BackgroundEmpagliflozin has been shown to reduce left ventricular mass index (LVMi) in patients with T2DM and CAD. The effects on myocardial ECV are unknown.MethodsThis was a prespecified substudy of the EMPA-HEART (Effects of Empagliflozin on Cardiac Structure in Patients with Type 2 Diabetes) CardioLink-6 trial in which 97 participants were randomized to receive empagliflozin 10 mg daily or placebo for 6 months. Data from 74 participants were included: 39 from the empagliflozin group and 35 from the placebo group. The main outcome was change in left ventricular ECV from baseline to 6 months determined by cardiac magnetic resonance (CMR). Other outcomes included change in LVMi, indexed intracellular compartment volume (iICV) and indexed extracellular compartment volume (iECV), and the fibrosis biomarkers soluble suppressor of tumorgenicity (sST2) and matrix metalloproteinase (MMP)-2.ResultsBaseline ECV was elevated in the empagliflozin group (29.6 ± 4.6%) and placebo group (30.6 ± 4.8%). Six months of empagliflozin therapy reduced ECV compared with placebo (adjusted difference: –1.40%; 95% confidence interval [CI]: –2.60 to –0.14%; p = 0.03). Empagliflozin therapy reduced iECV (adjusted difference: –1.5 ml/m²; 95% CI: –2.6 to –0.5 ml/m²; p = 0.006), with a trend toward reduction in iICV (adjusted difference: –1.7 ml/m²; 95% CI: –3.8 to 0.3 ml/m²; p = 0.09). Empagliflozin had no impact on MMP-2 or sST2.ConclusionsIn individuals with T2DM and CAD, 6 months of empagliflozin reduced ECV, iECV, and LVMi. No changes in MMP-2 and sST2 were seen. Further investigation into the mechanisms by which empagliflozin causes reverse remodeling is required. (Effects of Empagliflozin on Cardiac Structure in Patients With Type 2 Diabetes [EMPA-HEART]; NCT02998970)     

Interplay of Mineralocorticoid Receptor Antagonists and Empagliflozin in Heart Failure: EMPEROR-Reduced

BackgroundMineralocorticoid receptor antagonists (MRAs) and sodium glucose co-transporter 2 inhibitors favorably influence the clinical course of patients with heart failure and reduced ejection fraction.ObjectivesThis study sought to study the mutual influence of empagliflozin and MRAs in EMPEROR-Reduced (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Reduced Ejection Fraction).MethodsSecondary analysis that compared the effects of empagliflozin versus placebo in 3,730 patients with heart failure and a reduced ejection fraction, of whom 71% used MRAs at randomization.ResultsThe effects of empagliflozin on the primary endpoint, on most efficacy endpoints, and on safety were similar in patients receiving or not receiving an MRA (interaction p > 0.20). For cardiovascular death, the hazard ratios for the effect of empagliflozin versus placebo were 0.82 (95% confidence interval [CI]: 0.65 to 1.05) in MRA users and 1.19 (95% CI: 0.82 to 1.71) in MRA nonusers (interaction p = 0.10); a similar pattern was seen for all-cause mortality (interaction p = 0.098). Among MRA nonusers at baseline, patients in the empagliflozin group were 35% less likely than those in the placebo group to initiate treatment with an MRA following randomization (hazard ratio: 0.65; 95% CI: 0.49 to 0.85). Among MRA users at baseline, patients in the empagliflozin group were 22% less likely than those in the placebo group to discontinue treatment with an MRA following randomization (hazard ratio: 0.78; 95% CI: 0.64 to 0.96). Severe hyperkalemia was less common in the empagliflozin group.ConclusionsIn EMPEROR-Reduced, the use of MRAs did not influence the effect of empagliflozin to reduce adverse heart failure and renal outcomes. Treatment with empagliflozin was associated with less discontinuation of MRAs. (Empagliflozin Outcome Trial in Patients With Chronic Heart Failure With Reduced Ejection Fraction [EMPEROR-Reduced]; NCT03057977)     

Randomized Trial of Empagliflozin in Nondiabetic Patients With Heart Failure and Reduced Ejection Fraction

BackgroundLarge 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.ObjectivesThe 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.MethodsIn 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.ResultsEmpagliflozin 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).ConclusionsEmpagliflozin 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)     

Cardiac myofibroblast differentiation is attenuated by α3 integrin blockade: Potential role in post-MI remodeling

Cardiac fibroblasts and myofibroblasts are responsible for post-MI remodeling which occurs via regulation of extracellular matrix (ECM). Accelerated post-MI remodeling leads to excessive ECM deposition and fibrosis, contributing to impaired contractile function, arrhythmias, and heart failure. We have previously reported that type VI collagen induces myofibroblast differentiation in cultured cardiac fibroblasts, and that type VI collagen and myofibroblast content were both elevated in the myocardium 20 weeks post-MI. The purpose of this study was to determine the expression patterns of type VI collagen and myofibroblast content in early post-myocardial infarction (MI) remodeling to gain insight into whether type VI collagen induces in vivo myofibroblast differentiation via specific matrix-receptor interactions. Adult male Sprague-Dawley rats were anesthetized and left coronary arteries were permanently ligated. Histological tissue sections and whole tissue protein lysates were obtained from infarcted and non-infarcted areas of MI hearts and sham operated controls. At 3 days post-MI, we observed a significant increase in α₃ integrin expression (2.02 ± 0.18 fold); at 7 days post-infarction both type VI collagen (2.27 ± 0.18 fold) and myofibroblast (4.65 ± 0.6 fold) content increased. By 14 days myofibroblast content returned to sham control levels, although type VI collagen (2.42 ± 0.11 fold) was still elevated. In vitro cross-linking confirmed that the α₃ integrin interacts with type VI collagen, and α₃ integrin function blocking antibodies inhibited the differentiation of isolated cardiac fibroblasts. Collectively, our in vitro results indicate that the α₃ integrin receptor interacts with type VI collagen to promote myofibroblast differentiation, and that this interaction may impact in vivo post-MI remodeling.     

Extracellular matrix and cardiac remodelling

Cardiac remodelling associated with primitive and secondary cardiomyopathy is generally associated with changes in the expression in extracellular matrix (ECM) proteins as well as their transmembrane receptors, the integrins. It emerges now that the ECM provides a structural, chemical, and mechanical substrate that is essential in cardiac function and responses to pathophysiological signals. This review will describe the various elements of the ECM, its modifications that are associated with cardiac hypertrophy and heart failure, and the molecular basis bringing a better insight into the dynamics of the ECM.     

Cost-utility of empagliflozin in patients with type 2 diabetes at high cardiovascular risk

Aims

In the Empagliflozin, Cardiovascular Outcomes, and Mortality in Type 2 Diabetes (EMPA-REG) trial, empagliflozin reduced cardiovascular and all-cause mortality in type 2 diabetes (T2D) patients at high cardiovascular risk. We sought to estimate the cost-effectiveness of empagliflozin versus standard treatment for the prevention of cardiovascular morbidity and mortality in patients with T2D.

Antifibrotic effect of adrenomedullin on coronary adventitia in angiotensin II-induced hypertensive rats

OBJECTIVE: The extracellular matrix (ECM) determines the structural integrity of the heart and vasculature, participating in cardiovascular remodeling. We previously reported that adrenomedullin (AM) inhibited cellular proliferation and protein synthesis of cardiac fibroblasts; however, the precise mechanisms of AM actions as an antifibrotic factor remain unknown. The purpose of this study was to examine the biological actions of AM against the profibrotic factor angiotensin II (Ang II) in coronary adventitia. METHODS AND RESULTS: Rats with hypertension induced by Ang II infusion were administered 0.06 mug/kg/min recombinant human AM subcutaneously for 14 days. The AM infusion significantly (p<0.05) reduced the Ang II-induced increase of coronary adventitial fibroblasts expressing Ki-67 and alpha-smooth muscle actin (alpha-SMA) in the left ventricle, by 65%, and 62%, respectively, without affecting systolic blood pressure, left ventricle/body weight, or cross-sectional area of myocardial fibers. Collagen deposition of coronary arteries was reduced by the AM infusion (-24%, p<0.01), and these effects of AM were accompanied by significant reductions in gene expression of type 1 collagen (-49%, p<0.05) and transforming growth factor-beta1 (TGF-beta1) (-55%, p<0.01). In cultured cardiac fibroblasts, 10(-7) mol/L AM exerted an inhibitory effect on TGF-beta1-induced alpha-SMA expression (p<0.01) that was mimicked by 8-bromo-cAMP and attenuated by the protein kinase A inhibitor H-89. CONCLUSION: AM decreased Ang II-induced collagen deposition surrounding the coronary arteries, inhibiting myofibroblast differentiation and expressions of ECM-related genes in rats. The present findings further support the biological action of AM as an antifibrotic factor in vascular remodeling.     

Renal protection by sodium-glucose cotransporter 2 inhibitors and its underlying mechanisms in diabetic kidney disease

Aim

Diabetic kidney disease (DKD) is the most frequent cause of mortality and morbidity, leading a global health burden. This review will focus on the potential therapeutic interventions using Sodium-glucose cotransporter-2 (SGLT2) inhibitors that could prevent the development and progression of DKD.

Implications of the EMPA-REG Trial for Clinical Care and Research

EMPA-REG OUTCOME was a multicenter, randomized placebo-controlled trial that examined the effect of empagliflozin, a sodium–glucose cotransporter 2 (SGLT2) inhibitor in addition to standard of care in patients with type 2 diabetes and established cardiovascular (CV) disease. The primary goal was to assess CV safety, as mandated by the US Food and Drug Administration since 2008 for all new glucose-lowering agents. Secondary goals were to examine the effects of empagliflozin on microvascular outcomes and, in particular, kidney disease. This landmark study had several important findings, including striking reductions in the incidence of CV death and heart failure hospitalization and in the progression of renal dysfunction. In this review, we describe the trial’s main findings, discuss the possible mechanisms that could explain its results, suggest ways in which clinical care may be influenced, and propose directions for future research.     

Cyclic nucleotide phosphodiesterase 1A: a key regulator of cardiac fibroblast activation and extracellular matrix remodeling in the heart

Cardiac fibroblasts become activated and differentiate to smooth muscle-like myofibroblasts in response to hypertension and myocardial infarction (MI), resulting in extracellular matrix (ECM) remodeling, scar formation and impaired cardiac function. cAMP and cGMP-dependent signaling have been implicated in cardiac fibroblast activation and ECM synthesis. Dysregulation of cyclic nucleotide phosphodiesterase (PDE) activity/expression is also associated with various diseases and several PDE inhibitors are currently available or in development for treating these pathological conditions. The objective of this study is to define and characterize the specific PDE isoform that is altered during cardiac fibroblast activation and functionally important for regulating myofibroblast activation and ECM synthesis. We have found that Ca²⁺/calmodulin-stimulated PDE1A isoform is specifically induced in activated cardiac myofibroblasts stimulated by Ang II and TGF-β in vitro as well as in vivo within fibrotic regions of mouse, rat, and human diseased hearts. Inhibition of PDE1A function via PDE1-selective inhibitor or PDE1A shRNA significantly reduced Ang II or TGF-β-induced myofibroblast activation, ECM synthesis, and pro-fibrotic gene expression in rat cardiac fibroblasts. Moreover, the PDE1 inhibitor attenuated isoproterenol-induced interstitial fibrosis in mice. Mechanistic studies revealed that PDE1A modulates unique pools of cAMP and cGMP, predominantly in perinuclear and nuclear regions of cardiac fibroblasts. Further, both cAMP-Epac-Rap1 and cGMP-PKG signaling was involved in PDE1A-mediated regulation of collagen synthesis. These results suggest that induction of PDE1A plays a critical role in cardiac fibroblast activation and cardiac fibrosis, and targeting PDE1A may lead to regression of the adverse cardiac remodeling associated with various cardiac diseases.     

Empagliflozin reduces cardiovascular events,mortality and renal events in participants with type 2 diabetes after coronary artery bypass graft surgery: subanalysis of the EMPA-REG OUTCOME® randomised trial

Aims/hypothesis

After coronary artery bypass graft (CABG) surgery in individuals with type 2 diabetes, there remains a considerable residual cardiovascular risk. In the EMPA-REG OUTCOME® trial in participants with type 2 diabetes and established cardiovascular disease, empagliflozin reduced the risk of cardiovascular death by 38%, all-cause mortality by 32%, hospitalisation for heart failure by 35% and incident or worsening nephropathy by 39% vs placebo when given in addition to standard of care. The aim of this post hoc analysis of the EMPA-REG OUTCOME® trial was to determine the effects of the sodium glucose cotransporter 2 inhibitor empagliflozin on cardiovascular events and mortality in participants with type 2 diabetes and a self-reported history of CABG surgery.

Methods

The EMPA-REG OUTCOME® trial was a randomised, double-blind, placebo-controlled trial. Participants with type 2 diabetes and established cardiovascular disease were randomised 1:1:1 to receive placebo, empagliflozin 10 mg or empagliflozin 25 mg, once daily, in addition to standard of care. In subgroups by self-reported history of CABG (yes/no) at baseline, we assessed: cardiovascular death; all-cause mortality; hospitalisation for heart failure; and incident or worsening nephropathy (progression to macroalbuminuria, doubling of serum creatinine, initiation of renal replacement therapy or death due to renal disease). Differences in risk between empagliflozin and placebo were assessed using a Cox proportional hazards model.

Results

At baseline, 25% (1175/4687) of participants who received empagliflozin and 24% (563/2333) of participants who received placebo had a history of CABG surgery. In participants with a history of CABG surgery, HRs (95% CI) with empagliflozin vs placebo were 0.52 (0.32, 0.84) for cardiovascular mortality, 0.57 (0.39, 0.83) for all-cause mortality, 0.50 (0.32, 0.77) for hospitalisation for heart failure and 0.65 (0.50, 0.84) for incident or worsening nephropathy. Results were consistent between participants with and without a history of CABG surgery (p?>?0.05 for treatment by subgroup interactions).

Conclusions/interpretation

In participants with type 2 diabetes and a self-reported history of CABG surgery, treatment with empagliflozin was associated with profound reductions in cardiovascular and all-cause mortality, hospitalisation for heart failure, and incident or worsening nephropathy. These data have important implications for the secondary prevention of cardiovascular events after CABG in individuals with type 2 diabetes.

Trial registration:

ClinicalTrials.gov NCT01131676

     

Empagliflozin Improves Left Ventricular Diastolic Dysfunction in a Genetic Model of Type 2 Diabetes

Purpose

Cardiovascular (CV) diseases in type 2 diabetes (T2DM) represent an enormous burden with high mortality and morbidity. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have recently emerged as a new antidiabetic class that improves glucose control, as well as body weight and blood pressure with no increased risk of hypoglycemia. The first CV outcome study terminated with empagliflozin, a specific SGLT2 inhibitor, has shown a reduction in CV mortality and in heart failure hospitalization, suggesting a beneficial impact on cardiac function which remains to be demonstrated. This study was designed to examine the chronic effect of empagliflozin on left ventricular (LV) systolic and diastolic functions in a genetic model of T2DM, ob/ob mice.

Methods and Results

Cardiac phenotype was characterized by echocardiography, in vivo hemodynamics, histology, and molecular profiling. Our results demonstrate that empagliflozin significantly lowered HbA1c and slightly reduced body weight compared to vehicle treatment with no obvious changes in insulin levels. Empagliflozin also improved LV maximum pressure and in vivo indices of diastolic function. While systolic function was grossly not affected in both groups at steady state, response to dobutamine stimulation was significantly improved in the empagliflozin-treated group, suggesting amelioration of contractile reserve. This was paralleled by an increase in phospholamban (PLN) phosphorylation and increased SERCA2a/PLN ratio, indicative of enhanced SERCA2a function, further supporting improved cardiac relaxation and diastolic function. In addition, empagliflozin reconciled diabetes-associated increase in MAPKs and dysregulated phosphorylation of IRS1 and Akt, leading to improvement in myocardial insulin sensitivity and glucose utilization.

Conclusion

The data show that chronic treatment with empagliflozin improves diastolic function, preserves calcium handling and growth signaling pathways and attenuates myocardial insulin resistance in ob/ob mice, findings suggestive of a potential clinical utility for empagliflozin in the treatment of diastolic dysfunction.