DPP-4 inhibitors and risk of heart failure EXAMINEd

The Relationship Between Type 2 Diabetes, NAFLD, and Cardiovascular Risk

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) are strongly associated. Both also associate with an increased risk of cardiovascular disease (CVD).

RECENT FINDINGS

Several studies have provided evidence that NAFLD could be an independent CVD risk factor. Given the strong association between NAFLD and T2DM, assessing the independent CV effect of these two conditions remains challenging. However, patients with T2DM and NAFLD exhibit higher risk of CVD compared with T2DM without NAFLD suggesting a potential synergistic increase of CV risk in patients with both T2DM and NAFLD supported by several shared pathophysiological pathways. Several anti-diabetic therapies have shown beneficial effect on both NAFLD and CVD. Patients with T2DM and NAFLD should be considered at high risk of CVD and could benefit from more intensive CV prevention. Additional long-term follow-up is needed to demonstrate that the treatment of NAFLD effectively reduces the risk of CVD.

Treatment paradigm shifting implications of recent cardiovascular outcome trials: Core insights on the brink of the 2020ies

Based on cardiovascular (CV) outcome trials (CVOTs) being available on the brink of the 2020ies, CV safety assessed by major adverse CV event outcomes has been established for the classes of glucagon-like-peptide-1 receptor agonists (GLP1 RAs), sodium-glucose-co-transporter-2 inhibitors (SGLT2-is), and dipeptidyl-peptidase-4 inhibitors (DPP4is) in patients at very high CV risk. This should be relevant to the whole population with diabetes in general as well as the fact that no new serious and unexpected side effects have emerged within these trials. At the same time, treatment paradigm shifting CV benefit has been confirmed for two classes of diabetes medications (SGLT2is & GLP1 RAs), with important additional benefit of SGLT2is reducing heart failure and hard renal endpoints, both in patients with such diseases, but also in patients being in primary prevention. Moreover, the "soft" renal outcome of albuminurea progression seems to be attenuated by all three classes of drugs discussed in this overview. Still ongoing CVOTs are not expected to essentially change the current notions, with the potential of some differentiation regarding subgroups of primary heart failure populations in relation to treatment with SGLT2is.

The role of dipeptidylpeptidase-4 inhibitors in management of cardiovascular disease in diabetes; focus on linagliptin

Multiple population based analyses have demonstrated a high incidence of cardiovascular disease (CVD) and cardiovascular (CV) mortality in subjects with T2DM that reduces life expectancy by as much as 15 years. Importantly, the CV system is particularly sensitive to the metabolic and immune derangements present in obese pre-diabetic and diabetic individuals; consequently, CV dysfunction is often the initial CV derangement to occur and promotes the progression to end organ/tissue damage in T2DM. Specifically, diabetic CVD can manifest as microvascular complications, such as nephropathy, retinopathy, and neuropathy, as well as, macrovascular impairments, including ischemic heart disease, peripheral vascular disease, and cerebrovascular disease. Despite some progress in prevention and treatment of CVD, mainly via blood pressure and dyslipidemia control strategies, the impact of metabolic disease on CV outcomes is still a major challenge and persists in proportion to the epidemics of obesity and diabetes. There is abundant pre-clinical and clinical evidence implicating the DPP-4-incretin axis in CVD. In this regard, linagliptin is a unique DPP-4 inhibitor with both CV and renal safety profiles. Moreover, it exerts beneficial CV effects beyond glycemic control and beyond class effects. Linagliptin is protective for both macrovascular and microvascular complications of diabetes in preclinical models, as well as clinical models. Given the role of endothelial-immune cell interactions as one of the key events in the initiation and progression of CVD, linagliptin modulates these cell–cell interactions by affecting two important pathways involving stimulation of NO signaling and potent inhibition of a key immunoregulatory molecule.

Sodium-glucose Cotransporter-2 Inhibitors: Moving Beyond the Glycemic Treatment Goal

Revelations of the multifactorial pathogenesis of type 2 diabetes mellitus (T2DM) that extend beyond the role of insulin and glucose utilization have been crucial in redefining the treatment paradigm. The focus of treatment is currently directed towards achieving wide-ranging targets encompassing the management of cardiovascular comorbidities that have been evidenced as indispensable aspects of T2DM. While most currently prescribed antihyperglycemic agents have little or no effect on reducing cardiovascular risks, some have been associated with undesirable effects on common risk factors such as weight gain and cardiovascular sequelae. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are newer additions to the array of therapeutic agents for T2DM that have demonstrated robust glycemic control as mono and add-on therapies. Their unique renal mode of action, independent of insulin modulation, confers complementary metabolic benefits. By virtue of these effects, SGLT2i may have a distinct role in the revised treatment recommendations by established working groups such as the American Diabetes Association and the American Association of Clinical Endocrinologists that advocate a more comprehensive management of T2DM, not restricting to glycemic targets. The current review gives an overview of the changing treatment needs for T2DM and discusses the nonglycemic effects of SGLT2i. It provides an updated summary on the efficacy of canagliflozin, dapagliflozin, and empagliflozin in promoting weight loss, stabilizing blood pressure, and other favorable metabolic effects.

Cardiovascular Protection in the Treatment of Type 2 Diabetes: A Review of Clinical Trial Results Across Drug Classes

Patients with type 2 diabetes (T2DM) have a significantly higher risk of developing cardiovascular disease (CVD)-namely myocardial infarction, heart failure, and stroke. Despite clear advances in the prevention and treatment of CVD, the impact of T2DM on CVD outcome remains high and continues to escalate. Available evidence indicates that the risk of macrovascular complications increases with the severity of hyperglycemia, thus suggesting that the relation between metabolic disturbances and vascular damage is approximately linear. Although current antidiabetic drugs are highly effective for the management of hyperglycemia, most T2DM patients remain exposed to a substantial and concrete risk of CVD. Over the last decade many glucose-lowering agents have been tested for their safety and efficacy in T2DM with CVD. Noteworthy, most of these studies failed to show a significant benefit in terms of CV morbidity and mortality, despite intensive glycemic control. The recent trials Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME); Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide in Subjects with Type 2 Diabetes (SUSTAIN-6); Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER); and Insulin Resistance Intervention After Stroke (IRIS) have shed some light on this important clinical issue, thus showing a convincing effect of empagliflozin, liraglutide, and pioglitazone on CVD outcomes. Here we provide a critical and updated overview of the main glucose-lowering agents and their risk/benefit ratio for the prevention of CVD in patients with T2DM.

Cardiovascular Protection in the Treatment of Type 2 Diabetes: A Review of Clinical Trial Results Across Drug Classes

Patients with type 2 diabetes (T2DM) have a significantly higher risk of developing cardiovascular disease (CVD)-namely myocardial infarction, heart failure, and stroke. Despite clear advances in the prevention and treatment of CVD, the impact of T2DM on CVD outcome remains high and continues to escalate. Available evidence indicates that the risk of macrovascular complications increases with the severity of hyperglycemia, thus suggesting that the relation between metabolic disturbances and vascular damage is approximately linear. Although current antidiabetic drugs are highly effective for the management of hyperglycemia, most T2DM patients remain exposed to a substantial and concrete risk of CVD. Over the last decade many glucose-lowering agents have been tested for their safety and efficacy in T2DM with CVD. Noteworthy, most of these studies failed to show a significant benefit in terms of CV morbidity and mortality, despite intensive glycemic control. The recent trials Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME); Trial to Evaluate Cardiovascular and Other Long-term Outcomes with Semaglutide in Subjects with Type 2 Diabetes (SUSTAIN-6); Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results (LEADER); and Insulin Resistance Intervention After Stroke (IRIS) have shed some light on this important clinical issue, thus showing a convincing effect of empagliflozin, liraglutide, and pioglitazone on CVD outcomes. Here we provide a critical and updated overview of the main glucose-lowering agents and their risk/benefit ratio for the prevention of CVD in patients with T2DM.

Glucagon and heart in type 2 diabetes: new perspectives

Increased levels of glucagon in type 2 diabetes are well known and, until now, have been considered deleterious. However, glucagon has an important role in the maintenance of both heart and kidney function. Moreover, in the past, glucagon has been therapeutically used for heart failure treatment. The new antidiabetic drugs, dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter-2 inhibitors, are able to decrease and to increase glucagon levels, respectively, while contrasting data have been reported regarding the glucagon like peptide 1 receptors agonists. The cardiovascular outcome trials, requested by the FDA, raised some concerns about the possibility that the dipeptidyl peptidase-4 inhibitors can precipitate the heart failure, while, at least for empagliflozin, a positive effect has been shown in decreasing both cardiovascular death and heart failure. The recent LEADER Trial, showed a significant reduction of cardiovascular death with liraglutide, but a neutral effect on heart failure. A possible explanation of the results with the DPPIV inhibitors and empagliflozin might be related to their divergent effect on glucagon levels. Due to unclear effects of glucagon like peptide 1 receptor agonists on glucagon, the possible role of this hormone in the Leader trial remains unclear.

Analyses of Results From Cardiovascular Safety Trials With DPP-4 Inhibitors: Cardiovascular Outcomes, Predefined Safety Outcomes, and Pooled Analysis and Meta-analysis

The U.S. Food and Drug Administration requires that the cardiovascular (CV) safety of all new drugs for diabetes be demonstrated through pooled analyses of phase III studies or specifically designed trials. This requirement prompted several placebo-controlled, noninferiority CV safety trials in high-risk patients; to date, all completed trials showed that dipeptidyl peptidase (DPP)-4 inhibitors do not increase or reduce the risk of major CV events. These results apparently contrast with those of pooled analyses and meta-analyses of previous, smaller trials with metabolic end points, which had suggested a reduction of risk. However, the design of CV trials, which were required to demonstrate safety, is not adequate (for duration, management of concurrent therapies, etc.) for the assessment of potential therapeutic benefits. In addition, CV safety trials enroll patients at high risk of CV events, who are different from those included in earlier trials with metabolic end points. Differences in characteristics of patients enrolled probably account for most of the discrepancy in CV outcomes between CV safety studies and earlier trials. The availability of several large-scale trials with longer duration provides the unique opportunity for assessment of the safety of DPP-4 inhibitors not only with respect to major CV events but also with reference to other safety issues. For example, CV safety trials can be a source of information for pancreatitis, cancer, or hypoglycemia.

Diabetes Drugs and Cardiovascular Safety

Diabetes is a well-known risk factor of cardiovascular morbidity and mortality, and the beneficial effect of improved glycemic control on cardiovascular complications has been well established. However, the rosiglitazone experience aroused awareness of potential cardiovascular risk associated with diabetes drugs and prompted the U.S. Food and Drug Administration to issue new guidelines about cardiovascular risk. Through postmarketing cardiovascular safety trials, some drugs demonstrated cardiovascular benefits, while some antidiabetic drugs raised concern about a possible increased cardiovascular risk associated with drug use. With the development of new classes of drugs, treatment options became wider and the complexity of glycemic management in type 2 diabetes has increased. When choosing the appropriate treatment strategy for patients with type 2 diabetes at high cardiovascular risk, not only the glucose-lowering effects, but also overall benefits and risks for cardiovascular disease should be taken into consideration.

Heart Failure Considerations of Antihyperglycemic Medications for Type 2 Diabetes

Prevalent and incident heart failure (HF) is increased in people with type 2 diabetes mellitus, with risk directly associated with the severity of hyperglycemia. Furthermore, in patients with type 2 diabetes mellitus, mortality is increased ≈10-fold in patients with versus without HF. Reducing HF with antihyperglycemic therapies, however, has been unsuccessful until recently. In fact, HF as an important outcome in patients with type 2 diabetes mellitus seems to be heterogeneously modulated by antihyperglycemic medications, as evidenced by results from cardiovascular outcome trials (CVOTs) and large observational cohort studies. Appropriately powered and executed CVOTs are necessary to truly evaluate cardiovascular safety and efficacy of new antihyperglycemic medications, as reflected by the guidance of the US Food and Drug Administration and other regulatory agencies since 2008. In light of the best available evidence at present, metformin and the sodium-glucose-co-transporter 2-inhibitor empagliflozin seem to be especially advantageous with regard to HF effects, with their use associated with reduced HF events and improved mortality. Acarbose, the dipeptidyl-peptidase 4-inhibitor sitagliptin, the glucagon-like peptide 1-receptor agonist lixisenatide based on presently available CVOT results comprise reasonable additional options, as significant harm in terms of HF has been excluded for those drugs. Additions to this list are anticipated pending results of ongoing CVOTs. Although no HF harm was seen in CVOTs for insulin or sulfonylureas, they should be used only with caution in patients with HF, given their established high risk for hypoglycemia and some uncertainties on their safety in patients with HF derived from epidemiological observations. Pioglitazone is contraindicated in patients with HF>New York Heart Association I, despite some benefits suggested by CVOT subanalyses.

Cardiovascular outcome trials for anti-diabetes medication: A holy grail of drug development?

Since the time questions arose on cardiovascular safety of Rosiglitazone, FDA has suggested guidelines on conduct of studies on anti-diabetic drugs so as to prove that the cardiovascular risk is acceptable. Based on the cardiovascular risks of pre-approval clinical trials, guidelines have been made to conduct cardiovascular safety outcome trials (CVSOTs) prior to the drug approval or after the drug has been approved. Unlike the trials comparing the efficacy of antidiabetic agents, the CVSOTs examine the cardiovascular safety of a drug in comparison to standard of care. These trials are expensive aspects of drug development and are associated with various technical and operational challenges. More cost effective models of assessing cardiovascular safety like use of biomarkers, electronic medical records, pragmatic and factorial designs can be adopted. This article critically looks at the antidiabetic drug approval from a cardiovascular perspective by asking a few questions and arriving at answers.

Gliptins and Cardiovascular Outcomes: A Comparative and Critical Analysis after TECOS

The issue related to macrovascular outcomes and intensive glycemic control was hotly debated after the publication of landmark trials like ACCORD, ADVANCE, and VADT. The only benefits seem to come from intervening early on in the disease process as indicated by the 10-year UKPDS follow-up. To complicate matters USFDA made it mandatory for modern drugs to conduct cardiovascular safety trials in high-risk populations after the 2008 rosiglitazone scare. This led to all the modern group of drugs designing cardiovascular safety trials (gliptins, GLP-1 agonists, and SGLT-2 inhibitors) to meet USFDA regulatory requirements. We saw publication of the first 2 randomized trials with gliptins published a year and a half back. On the face value SAVOR TIMI and EXAMINE satisfied the primary composite CV end-points. However, issues related to significant increase in heart failure and all-cause 7-day on-treatment mortality created a lot of confusion. FDA reanalysis of these data (especially SAVOR) raises a lot of doubts as far as CV safety of these groups of drugs was concerned. Hence, all eyes were on TECOS, which was published this year. We take a microscopic look at these trials trying to understand where we stand as from now on this issue.

DPP-4 inhibitors, heart failure and type 2 diabetes: all eyes on safety

Epidemiological analyses have clearly outlined the association between heart failure (HF) and diabetes (DM). HF patients with concomitant DM show a further increase in morbidity and mortality due to coexistence of several mechanisms including disturbed neurohormonal axis as well as structural and functional abnormalities occurring in the diabetic myocardium. Although several studies have shown that poor glycemic control-as indicated by HbA1c levels-may be associated with an increased risk of HF, this issue remains poorly understood and further evidence is required to show unequivocal benefits of this approach. In the attempt to explore the effects of new anti-hyperglycemic therapies, randomized trials have shown that some glucose-lowering drugs-thought not affecting cardiovascular (CV) death or ischemic complications-might significantly increase the risk of HF-hospitalizations in DM patients. Specifically, the use of dipeptidyl-peptidase-4 (DDP-4) inhibitors (DPP-4i) has recently raised a major safety concern owing to an increase of HF hospitalizations in SAVOR-TIMI 53 trial. In contrast with these findings, the more recent TECOS study as well as new TECOS sub-analyses presented at the last ESC Congress-have yielded to the conclusion that the DPP-4i sitagliptin is not associated with any sort of HF risk. Therefore, increased risk of HF hospitalizations does not seem to be a class effect of DPP-4i. The present article critically discusses available evidence concerning DPP-4i and risk of HF in patients with type 2 diabetes (T2D). The use of DPP-4i in combination therapy is also discussed, in light of the recent EMPA-REG trial.

Antidiabetic treatment with gliptins: focus on cardiovascular effects and outcomes

The traditional oral pharmacological therapy for type 2 diabetes mellitus (T2DM) has been based on the prescription of metformin, a biguanide, as first line antihyperglycemic agent world over. It has been demonstrated that after 3 years of treatment, approximately 50 % of diabetic patients could achieve acceptable glucose levels with monotherapy; but by 9 years this had declined to only 25 %. Therefore, the implementation of a combined pharmacological therapy acting via different pathways becomes necessary, and its combination with a compound of the sulfonylurea group was along decades the most frequently employed prescription in routine clinical practice. Meglitinides, glitazones and alpha-glucosidase inhibitors were subsequently developed, but the five mentioned groups of oral antihyperglycemic agents are associated with variable degrees of undesirable or even severe cardiovascular events. The gliptins—also called dipeptidyl peptidase 4 (DPP4) inhibitors—are an additional group of antidiabetic compounds with increasing clinical use. We review the status of the gliptins with emphasis on their capabilities to positively or negatively affect the cardiovascular system, and their potential involvement in major adverse cardiovascular events (MACE). Alogliptin, anagliptin, linagliptin, saxagliptin, sitagliptin, teneligliptin and vildagliptin are the compounds currently in clinical use. Regardless differences in chemical structure and metabolic pathways, gliptins as a group exert favorable changes in experimental models. These changes, as an almost general rule, include improved endothelial function, reduction of inflammatory markers, oxidative stress ischemia/reperfusion injury and atherogenesis. In addition, increased adiponectin levels and modest decreases in lipidemia and blood pressure were reported. In clinical settings, several trials—notably the longer one, employing sitagliptin, with a mean follow-up period of 3 years—did not show an increased risk for ischemic events. Anyway, it should be emphasized that the encouraging results from basic science were not yet translated into clinical evidence, probably due the multiple and pleiotropic enzymatic effects of DPP4 inhibition. Moreover, when employing saxagliptin, while the drug was not associated with an augmented risk for ischemic events, it should be pinpointed that the rate of hospitalization for heart failure was significantly increased. Gliptins as a group constitute a widely accepted therapy for the management of T2DM, usually as a second-line medication. Nonetheless, for the time being, a definite relationship between gliptins treatment and improved cardiovascular outcomes remains uncertain and needs yet to be proven.