Sitagliptin does not reduce the risk of cardiovascular death or hospitalization for heart failure following myocardial infarction in patients with diabetes: observations from TECOS

The benefits of oral glucose-lowering agents: GLP-1 receptor agonists, DPP-4 and SGLT-2 inhibitors on myocardial ischaemia/reperfusion injury

Myocardial infarction (MI) is a life-threatening cardiovascular disease that, on average, results in 8.5 million deaths worldwide each year. Timely revascularization of occluded vessels is a critical method of myocardial salvage. However, reperfusion paradoxically leads to the worsening of myocardial damage known as myocardial ischaemia/reperfusion injury (MI/RI). Therefore, reducing the size of myocardial infarction after reperfusion is critical and remains an important therapeutic goal. The susceptibility of the myocardium to MI/RI may be increased by diabetes. Currently, some traditional antidiabetic agents such as metformin reduce MI/RI by decreasing inflammation, inhibiting oxidative stress, and improving vascular endothelial function. This appears to be a new direction for the treatment of MI/RI. Recent cardiovascular outcome trials have shown that several oral antidiabetic agents, including glucagon-like peptide-1 receptor agonists (GLP-1RAs), dipeptidyl peptidase-4 inhibitors (DPP-4is), and sodium-glucose-linked transporter-2 inhibitors (SGLT-2is), not only have good antidiabetic effects but also have a protective effect on myocardial protection. This article aims to discuss the mechanisms and effects of oral antidiabetic agents, including GLP-1RAs, DPP-4is, and SGLT-2is, on MI/RI to facilitate their clinical application.

Emerging role of antidiabetic drugs in cardiorenal protection

The global prevalence of diabetes mellitus (DM) has led to widespread multi-system damage, especially in cardiovascular and renal functions, heightening morbidity and mortality. Emerging antidiabetic drugs sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1RAs), and dipeptidyl peptidase-4 inhibitors (DPP-4i) have demonstrated efficacy in preserving cardiac and renal function, both in type 2 diabetic and non-diabetic individuals. To understand the exact impact of these drugs on cardiorenal protection and underlying mechanisms, we conducted a comprehensive review of recent large-scale clinical trials and basic research focusing on SGLT2i, GLP-1RAs, and DPP-4i. Accumulating evidence highlights the diverse mechanisms including glucose-dependent and independent pathways, and revealing their potential cardiorenal protection in diabetic and non-diabetic cardiorenal disease. This review provides critical insights into the cardiorenal protective effects of SGLT2i, GLP-1RAs, and DPP-4i and underscores the importance of these medications in mitigating the progression of cardiovascular and renal complications, and their broader clinical implications beyond glycemic management.

Changing the Concept: From the Traditional Glucose-centric to the New Cardiorenal-metabolic Approach for the Treatment of Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) is a chronic disease with a constantly increasing prevalence worldwide. It is well established that T2DM affects both the macro- and microvasculature, and its presence is associated with a high risk of acute and chronic cardiovascular events. Traditionally, the management of T2DM has been mainly focused on the optimization of blood glucose levels with the use of antidiabetic medications. During recent years, however, an impressive accumulation of evidence has arisen from studies designed to explore the plausible effects of new antidiabetic drugs on cardiovascular outcomes in patients with diabetes. This review article aims to emphasize the findings of these studies and to highlight the substantial role of the newer classes of antidiabetic drugs in treating T2DM in a holistic, cardiorenal-metabolic approach, thus shifting the paradigm from the traditional, simplistic, glucose-lowering approach.

Dipeptidyl peptidase-4 inhibitors, glucagon-like peptide 1 receptor agonists and sodium-glucose co-transporter-2 inhibitors for people with cardiovascular disease: a network meta-analysis

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of death globally. Recently, dipeptidyl peptidase-4 inhibitors (DPP4i), glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose co-transporter-2 inhibitors (SGLT2i) were approved for treating people with type 2 diabetes mellitus. Although metformin remains the first-line pharmacotherapy for people with type 2 diabetes mellitus, a body of evidence has recently emerged indicating that DPP4i, GLP-1RA and SGLT2i may exert positive effects on patients with known CVD.

OBJECTIVES

To systematically review the available evidence on the benefits and harms of DPP4i, GLP-1RA, and SGLT2i in people with established CVD, using network meta-analysis.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and the Conference Proceedings Citation Index on 16 July 2020. We also searched clinical trials registers on 22 August 2020. We did not restrict by language or publication status.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) investigating DPP4i, GLP-1RA, or SGLT2i that included participants with established CVD. Outcome measures of interest were CVD mortality, fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, all-cause mortality, hospitalisation for heart failure (HF), and safety outcomes.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened the results of searches to identify eligible studies and extracted study data. We used the GRADE approach to assess the certainty of the evidence. We conducted standard pairwise meta-analyses and network meta-analyses by pooling studies that we assessed to be of substantial homogeneity; subgroup and sensitivity analyses were also pursued to explore how study characteristics and potential effect modifiers could affect the robustness of our review findings. We analysed study data using the odds ratios (ORs) and log odds ratios (LORs) with their respective 95% confidence intervals (CIs) and credible intervals (Crls), where appropriate. We also performed narrative synthesis for included studies that were of substantial heterogeneity and that did not report quantitative data in a usable format, in order to discuss their individual findings and relevance to our review scope.

MAIN RESULTS

We included 31 studies (287 records), of which we pooled data from 20 studies (129,465 participants) for our meta-analysis. The majority of the included studies were at low risk of bias, using Cochrane's tool for assessing risk of bias. Among the 20 pooled studies, six investigated DPP4i, seven studied GLP-1RA, and the remaining seven trials evaluated SGLT2i. All outcome data described below were reported at the longest follow-up duration. 1. DPP4i versus placebo Our review suggests that DPP4i do not reduce any risk of efficacy outcomes: CVD mortality (OR 1.00, 95% CI 0.91 to 1.09; high-certainty evidence), myocardial infarction (OR 0.97, 95% CI 0.88 to 1.08; high-certainty evidence), stroke (OR 1.00, 95% CI 0.87 to 1.14; high-certainty evidence), and all-cause mortality (OR 1.03, 95% CI 0.96 to 1.11; high-certainty evidence). DPP4i probably do not reduce hospitalisation for HF (OR 0.99, 95% CI 0.80 to 1.23; moderate-certainty evidence). DPP4i may not increase the likelihood of worsening renal function (OR 1.08, 95% CI 0.88 to 1.33; low-certainty evidence) and probably do not increase the risk of bone fracture (OR 1.00, 95% CI 0.83 to 1.19; moderate-certainty evidence) or hypoglycaemia (OR 1.11, 95% CI 0.95 to 1.29; moderate-certainty evidence). They are likely to increase the risk of pancreatitis (OR 1.63, 95% CI 1.12 to 2.37; moderate-certainty evidence). 2. GLP-1RA versus placebo Our findings indicate that GLP-1RA reduce the risk of CV mortality (OR 0.87, 95% CI 0.79 to 0.95; high-certainty evidence), all-cause mortality (OR 0.88, 95% CI 0.82 to 0.95; high-certainty evidence), and stroke (OR 0.87, 95% CI 0.77 to 0.98; high-certainty evidence). GLP-1RA probably do not reduce the risk of myocardial infarction (OR 0.89, 95% CI 0.78 to 1.01; moderate-certainty evidence), and hospitalisation for HF (OR 0.95, 95% CI 0.85 to 1.06; high-certainty evidence). GLP-1RA may reduce the risk of worsening renal function (OR 0.61, 95% CI 0.44 to 0.84; low-certainty evidence), but may have no impact on pancreatitis (OR 0.96, 95% CI 0.68 to 1.35; low-certainty evidence). We are uncertain about the effect of GLP-1RA on hypoglycaemia and bone fractures. 3. SGLT2i versus placebo This review shows that SGLT2i probably reduce the risk of CV mortality (OR 0.82, 95% CI 0.70 to 0.95; moderate-certainty evidence), all-cause mortality (OR 0.84, 95% CI 0.74 to 0.96; moderate-certainty evidence), and reduce the risk of HF hospitalisation (OR 0.65, 95% CI 0.59 to 0.71; high-certainty evidence); they do not reduce the risk of myocardial infarction (OR 0.97, 95% CI 0.84 to 1.12; high-certainty evidence) and probably do not reduce the risk of stroke (OR 1.12, 95% CI 0.92 to 1.36; moderate-certainty evidence). In terms of treatment safety, SGLT2i probably reduce the incidence of worsening renal function (OR 0.59, 95% CI 0.43 to 0.82; moderate-certainty evidence), and probably have no effect on hypoglycaemia (OR 0.90, 95% CI 0.75 to 1.07; moderate-certainty evidence) or bone fracture (OR 1.02, 95% CI 0.88 to 1.18; high-certainty evidence), and may have no impact on pancreatitis (OR 0.85, 95% CI 0.39 to 1.86; low-certainty evidence). 4. Network meta-analysis Because we failed to identify direct comparisons between each class of the agents, findings from our network meta-analysis provided limited novel insights. Almost all findings from our network meta-analysis agree with those from the standard meta-analysis. GLP-1RA may not reduce the risk of stroke compared with placebo (OR 0.87, 95% CrI 0.75 to 1.0; moderate-certainty evidence), which showed similar odds estimates and wider 95% Crl compared with standard pairwise meta-analysis. Indirect estimates also supported comparison across all three classes. SGLT2i was ranked the best for CVD and all-cause mortality.

AUTHORS' CONCLUSIONS

Findings from both standard and network meta-analyses of moderate- to high-certainty evidence suggest that GLP-1RA and SGLT2i are likely to reduce the risk of CVD mortality and all-cause mortality in people with established CVD; high-certainty evidence demonstrates that treatment with SGLT2i reduce the risk of hospitalisation for HF, while moderate-certainty evidence likely supports the use of GLP-1RA to reduce fatal and non-fatal stroke. Future studies conducted in the non-diabetic CVD population will reveal the mechanisms behind how these agents improve clinical outcomes irrespective of their glucose-lowering effects.

CARDIOVASCULAR EFFECTS OF NON-INSULIN GLUCOSE-LOWERING AGENTS: A COMPREHENSIVE REVIEW OF TRIAL EVIDENCE AND POTENTIAL CARDIOPROTECTIVE MECHANISMS

Type 2 diabetes mellitus (T2DM) is highly prevalent and associated with a 2-fold increased mortality, mostly explained by cardiovascular diseases. Trial evidence on older glucose-lowering agents such as metformin and sulfonylureas is limited in terms of cardiovascular efficacy. Since 2008, after rosiglitazone was observed to increase the risk of myocardial infarction and heart failure (HF), cardiovascular outcome trials (CVOT) have been required by regulators for licensing new glucose-lowering agents. In the following CVOTs, dipeptidyl peptidase 4 inhibitors (DPP4i) have been shown to be safe but not to improve morbidity/mortality, except for saxagliptin which increased the risk of HF. Several glucagon-like peptide-1 receptor agonists (GLP1-Ra) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been demonstrated to reduce the risk of cardiovascular morbidity and mortality. SGLT2i have shown a class effect for the reduction in risk of HF events in patients with T2DM, leading to trials testing their efficacy/safety in HF regardless of T2DM. In the DAPA-HF and the EMPEROR-Reduced trials dapagliflozin and empagliflozin, respectively, improved cardiovascular mortality/morbidity in patients with HF and reduced ejection fraction (HFrEF), with and without T2DM. Therefore, these drugs are now key part of HFrEF pharmacotherapy. In the SOLOIST-WHF, sotagliflozin reduced cardiovascular mortality/morbidity in patients with T2DM and a recent acute episode of HF regardless of EF. The DELIVER and the EMPEROR-Preserved are testing dapagliflozin and empagliflozin, respectively, in patients with HF with mildly reduced and preserved EF. A strong renal protective role of SGLT2i has also emerged in trials enrolling patients with and without T2DM.

Roles of Sodium-Glucose Cotransporter 2 of Mesangial Cells in Diabetic Kidney Disease

We have been studying the presence of sodium-glucose cotransporter 2 (SGLT2) in mesangial cells and pericytes since 1992. Recent large placebo-controlled studies of SGLT2 inhibitors in patients with type 2 diabetes mellitus have reported desirable effects of the inhibitors on the diabetic kidney and the diabetic heart. Most studies have indicated that these effects of SGLT2 inhibitors could be mediated by the tubuloglomerular feedback system. However, a recent study about urine sodium excretion in the presence of an SGLT2 inhibitor did not show any increases in urine sodium excretion. A very small dose of an SGLT2 inhibitor did not inhibit SGLT2 at the S1 segment of proximal tubules. Moreover, SGLT2 inhibition protects against progression in chronic kidney disease with and without type 2 diabetes. In these circumstances, the tubuloglomerular feedback hypothesis involves several theoretical concerns that must be clarified. The presence of SGLT2 in mesangial cells seems to be very important for diabetic nephropathy. We now propose a novel mechanism by which the desirable effects of SGLT2 inhibitors on diabetic nephropathy are derived from the direct effect on SGLT2 expressed in mesangial cells.

Effects of anti-diabetes medications on cardiovascular and kidney outcomes in Asian patients with type 2 diabetes: a rapid evidence assessment and narrative synthesis

BACKGROUND

The cardiovascular and kidney safety of glucose-lowering drugs is a key concern in type 2 diabetes (T2D). We evaluated cardiorenal outcomes with glucose-lowering drugs in Asian patients, who comprise over half of T2D cases globally.

RESEARCH DESIGN AND METHODS

A rapid evidence assessment was conducted for phase III or IV, double-blind, randomized clinical trials of glucose-lowering drugs reporting cardiovascular or kidney outcomes for Asian T2D patients (Embase, Medline, Cochrane Library databases: 1 January 2008-14 June 2020).

RESULTS

Fifty-four publications reported exploratory data for Asians from 18 trials of dipeptidyl peptidase-4 (DPP-4) inhibitors, sodium-glucose co-transporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and insulin analogs. SGLT2 inhibitors and several GLP-1 receptor agonists were associated with reduced cardiovascular risk in Asian T2D patients, while DPP-4 inhibitors exhibited cardiovascular safety. SGLT2 inhibitors also appeared to reduce renal risk; however, kidney outcomes were lacking for DPP-4 inhibitors other than linagliptin and GLP-1 receptor agonists in Asian patients. Insulin data were inconclusive as the only trial conducted used different types of insulin as both treatment and comparator.

CONCLUSIONS

Cardiorenal outcomes with glucose-lowering drugs in Asian T2D patients were similar to outcomes in the overall multinational cohorts of these trials. DPP-4 inhibitors appear to demonstrate cardiovascular safety in Asians, while SGLT2 inhibitors and some GLP-1 receptor agonists may reduce cardiorenal and cardiovascular risk, respectively.

Safety and Efficacy of Adding Dapagliflozin to Furosemide in Type 2 Diabetic Patients With Decompensated Heart Failure and Reduced Ejection Fraction

Background: Heart failure is the most common cause of hospitalization in elderly patients. It is likely that many of the mechanisms that contribute to reductions in systolic and diastolic function, seen in diabetic patients, place them at an increased risk of heart failure. Diuretic therapy, especially loop diuretics, is the usual way of managing congestion, particularly in volume-overloaded patients. Little is known about the beneficial effect of dapagliflozin when added to loop diuretics in managing patients with decompensated heart failure. Aim: To assess the effect of the addition of dapagliflozin to furosemide in managing decompensated patient with heart failure and reduced left ventricular ejection fraction in terms of weight loss and dyspnea improvement. Patients and Methods: The study included 100 type 2 diabetic patients who were admitted with decompensated heart failure. The study population was randomly divided into two arms. Serum electrolytes and kidney functions were followed up during their hospital stay. Results: With dapagliflozin, there was a statistically significant difference between the two groups regarding the change in body weight and body mass index. The diuresis parameters including urine output, total fluid loss, and fluid balance also showed a statistically significant difference in favor of the use of dapagliflozin, with no significant change in serum potassium or kidney functions. There was significant improvement in patient-reported dyspnea scores with the use of dapagliflozin. Conclusions: Dapagliflozin may provide a new drug option in the treatment of heart failure especially among vulnerable group of diabetics. It had no remarkable effects on serum potassium level and kidney functions. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT04385589.

2020 Consensus of Taiwan Society of Cardiology on the pharmacological management of patients with type 2 diabetes and cardiovascular diseases

The global incidence and prevalence of type 2 diabetes have been escalating in recent decades. The total diabetic population is expected to increase from 415 million in 2015 to 642 million by 2040. Patients with type 2 diabetes have an increased risk of atherosclerotic cardiovascular disease (ASCVD). About two-thirds of patients with type 2 diabetes died of ASCVD. The association between hyperglycemia and elevated cardiovascular (CV) risk has been demonstrated in multiple cohort studies. However, clinical trials of intensive glucose reduction by conventional antidiabetic agents did not significantly reduce macrovascular outcomes.In December 2008, U.S. Food and Drug Administration issued a mandate that every new antidiabetic agent requires rigorous assessments of its CV safety. Thereafter, more than 200,000 patients have been enrolled in a number of randomized controlled trials (RCTs). These trials were initially designed to prove noninferiority. It turned out that some of these trials demonstrated superiority of some new antidiabetic agents versus placebo in reducing CV endpoints, including macrovascular events, renal events, and heart failure. These results are important in clinical practice and also provide an opportunity for academic society to formulate treatment guidelines or consensus to provide specific recommendations for glucose control in various CV diseases.In 2018, the Taiwan Society of Cardiology (TSOC) and the Diabetes Association of Republic of China (DAROC) published the first joint consensus on the "Pharmacological Management of Patients with Type 2 Diabetes and Cardiovascular Diseases." In 2020, TSOC appointed a new consensus group to revise the previous version. The updated 2020 consensus was comprised of 5 major parts: (1) treatment of diabetes in patients with multiple risk factors, (2) treatment of diabetes in patients with coronary heart disease, (3) treatment of diabetes in patients with stage 3 chronic kidney disease, (4) treatment of diabetes in patients with a history of stroke, and (5) treatment of diabetes in patients with heart failure. The members of the consensus group thoroughly reviewed all the evidence, mainly RCTs, and also included meta-analyses and real-world evidence. The treatment targets of HbA1c were finalized. The antidiabetic agents were ranked according to their clinical evidence. The consensus is not mandatory. The final decision may need to be individualized and based on clinicians' discretion.

Changes in Myocardial Metabolism Preceding Sudden Cardiac Death

Heart disease is widely recognized as a major cause of death worldwide and is the leading cause of mortality in the United States. Centuries of research have focused on defining mechanistic alterations that drive cardiac pathogenesis, yet sudden cardiac death (SCD) remains a common unpredictable event that claims lives in every age group. The heart supplies blood to all tissues while maintaining a constant electrical and hormonal feedback communication with other parts of the body. As such, recent research has focused on understanding how myocardial electrical and structural properties are altered by cardiac metabolism and the various signaling pathways associated with it. The importance of cardiac metabolism in maintaining myocardial function, or lack thereof, is exemplified by shifts in cardiac substrate preference during normal development and various pathological conditions. For instance, a shift from fatty acid (FA) oxidation to oxygen-sparing glycolytic energy production has been reported in many types of cardiac pathologies. Compounded by an uncoupling of glycolysis and glucose oxidation this leads to accumulation of undesirable levels of intermediate metabolites. The resulting accumulation of intermediary metabolites impacts cardiac mitochondrial function and dysregulates metabolic pathways through several mechanisms, which will be reviewed here. Importantly, reversal of metabolic maladaptation has been shown to elicit positive therapeutic effects, limiting cardiac remodeling and at least partially restoring contractile efficiency. Therein, the underlying metabolic adaptations in an array of pathological conditions as well as recently discovered downstream effects of various substrate utilization provide guidance for future therapeutic targeting. Here, we will review recent data on alterations in substrate utilization in the healthy and diseased heart, metabolic pathways governing cardiac pathogenesis, mitochondrial function in the diseased myocardium, and potential metabolism-based therapeutic interventions in disease.

Impact of diabetes mellitus on mortality in patients with acute heart failure: a prospective cohort study

Background

Although more than one-third of the patients with acute heart failure (AHF) have diabetes mellitus (DM), it is unclear if DM has an adverse impact on clinical outcomes. This study compared the outcomes in patients hospitalized for AHF stratified by DM and left ventricular ejection fraction (LVEF).

Methods

The Korean Acute Heart Failure registry prospectively enrolled and followed 5625 patients from March 2011 to February 2019. The primary endpoints were in-hospital and overall all-cause mortality. We evaluated the impact of DM on these endpoints according to HF subtypes and glycemic control.

Results

During a median follow-up of 3.5 years, there were 235 (4.4%) in-hospital mortalities and 2500 (46.3%) overall mortalities. DM was significantly associated with increased overall mortality after adjusting for potential confounders (adjusted hazard ratio [HR] 1.11, 95% confidence interval [CI] 1.03–1.22). In the subgroup analysis, DM was associated with higher a risk of overall mortality in heart failure with reduced ejection fraction (HFrEF) only (adjusted HR 1.14, 95% CI 1.02–1.27). Inadequate glycemic control (HbA1c ≥ 7.0% within 1 year after discharge) was significantly associated with a higher risk of overall mortality compared with adequate glycemic control (HbA1c < 7.0%) (44.0% vs. 36.8%, log-rank p = 0.016).

Conclusions

DM is associated with a higher risk of overall mortality in AHF, especially HFrEF. Well-controlled diabetes (HbA1c < 7.0%) is associated with a lower risk of overall mortality compared to uncontrolled diabetes.

Trial registration ClinicalTrial.gov, NCT01389843. Registered July 6, 2011. https://clinicaltrials.gov/ct2/show/NCT01389843