Will long-acting glucagon-like peptide-1 analogues recapitulate our agonizing experience with cyclic AMP-dependent positive inotropic agents in heart failure?

Glucagon-Like Peptide-1 Receptor Agonists Across the Spectrum of Heart Failure

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have been used to reduce body weight in overweight or people with obesity and to improve glycemic control and cardiovascular outcomes among people with type 2 diabetes (T2D) and a high cardiovascular risk. However, the effects of GLP-1 RAs may be modified by the presence of heart failure (HF). In this review, we summarize the evidence for the use of GLP-1 RA across a patient's risk with a particular focus on HF. After a careful review of the literature, we challenge the current views about the use of GLP-1 RAs and suggest performing active HF screening (with directed clinical history, physical examination, an echocardiogram, and natriuretic peptides) before initiating a GLP-1 RA. After HF screening, we suggest GLP-1 RA treatment decisions as follows: (1) in people with T2D without HF, GLP-1 RAs should be used for reducing the risk of myocardial infarction and stroke, with a possible effect to reduce the risk of HF hospitalizations; (2) in patients with HF and preserved ejection fraction, GLP-1 RAs do not reduce HF hospitalizations but may reduce atherosclerotic events, and their use may be considered in an individualized manner; and (3) in patients with HF and reduced ejection fraction, the use of GLP-1 RAs warrants caution due to potential risk of worsening HF events and arrhythmias, pending risk-benefit data from further studies.

Glucagon-like peptide 1 receptor agonists in patients with type 2 diabetes with and without chronic heart failure: A meta-analysis of randomized placebo-controlled outcome trials

AIM

Glucagon-like peptide 1 receptor agonists (GLP1-RA) reduce atherosclerotic events in patients with type 2 diabetes (T2D) and a high cardiovascular risk. The effect of GLP1-RA to reduce heart failure (HF) has been inconsistent across T2D trials, and individual trials were underpowered to assess the effect of GLP1-RA according to HF history. In this meta-analysis we aim to assess the effect of GLP1-RA in patients with and without HF history in stable ambulatory patients with T2D.

METHODS

Random-effects meta-analysis of placebo-controlled trials. The hazard ratio (HR) and 95% confidence intervals (95% CI) were extracted from the treatment effect estimates of HF subgroup analyses reported in each individual study. The primary outcome was a composite of HF hospitalization or cardiovascular death.

RESULTS

In total, 54 092 patients with T2D from seven randomized controlled trials were included, of whom 8460 (16%) had HF history. Compared with placebo, GLP1-RA did not reduce the composite of HF hospitalization or cardiovascular death in patients with HF history: HR 0.96, 95% CI: 0.84-1.08, but reduced this outcome in patients without HF history: HR 0.84, 95% CI: 0.76-0.92. GLP1-RA did not reduce all-cause death in patients with HF history: HR 0.98, 95% CI: 0.86-1.11, but reduced mortality in patients without HF history: HR 0.85, 95% CI: 0.79-0.92. GLP1-RA reduced atherosclerotic events regardless of HF history: HR 0.85, 95% CI: 0.75-0.97 with HF, and HR 0.88, 95% CI: 0.83-0.93 without HF.

CONCLUSIONS

Treatment with GLP1-RA did not reduce HF hospitalizations and mortality in patients with concomitant T2D and HF, but may prevent new-onset HF and mortality in patients with T2D without HF. The reduction of atherosclerotic events with GLP1-RA was not influenced by HF history status.

Risk of adverse events with liraglutide in heart failure with reduced ejection fraction: A post hoc analysis of the FIGHT trial

AIM

To perform a post hoc analysis of the FIGHT trial, evaluating the effect of liraglutide (vs. placebo) on the totality of events in patients with heart failure with reduced ejection fraction (HFrEF).

MATERIALS AND METHODS

FIGHT was a double-blind randomized controlled trial (RCT) that studied liraglutide versus placebo in 300 recently hospitalized patients with HFrEF followed for 180 days. The main outcome of the present analysis was total events of hospitalizations for heart failure (HF) or all-cause death. Secondary outcomes included total arrhythmic events and prespecified total events of interest (arrhythmias, sudden cardiac death, acute coronary syndrome, worsening HF, cerebrovascular event, venous thromboembolism, lightheadedness, presyncope/syncope or worsening renal function). Treatment effect was evaluated with negative binomial regression.

RESULTS

Compared to placebo, there was a trend towards increased risk with liraglutide of total HF hospitalizations or all-cause deaths (96 vs. 143 events, incidence rate ratio [IRR] 1.41, 95% confidence interval [CI] 0.98-2.04; P = 0.064) and total arrhythmias (21 vs. 39, IRR 1.76, 95% CI 0.92-3.37; P = 0.088). Total prespecified events of interest were increased with liraglutide compared to placebo (196 vs. 295, IRR 1.43, 95% CI 1.06-1.92; P = 0.018). The risk of HF hospitalizations or all-cause deaths with liraglutide was higher among patients in New York Heart Association (NYHA) Class III to IV (IRR 1.86, 95% CI 1.21-2.85) than in those in NYHA Class I to II (IRR 0.62, 95% CI 0.31-1.23; interaction P = 0.008), and among patients with diabetes (interaction P = 0.051). The risk of arrhythmic events was higher among those without an implanted cardiac device (interaction P = 0.047).

CONCLUSIONS

In patients with HFrEF, liraglutide might increase the risk of cardiovascular adverse effects, an effect possibly driven by excess risk of arrhythmias and worsening HF events. As this was a post hoc analysis, these results should be interpreted as exploratory and hypothesis-generating. Further RCTs must be conducted before drawing definitive conclusions.

Differential Pathophysiological Mechanisms in Heart Failure With a Reduced or Preserved Ejection Fraction in Diabetes

Diabetes promotes the development of both heart failure with a reduced ejection fraction and heart failure with a preserved ejection fraction through diverse mechanisms, which are likely mediated through hyperinsulinemia rather than hyperglycemia. Diabetes promotes nutrient surplus signaling (through Akt and mammalian target of rapamycin complex 1) and inhibits nutrient deprivation signaling (through sirtuin-1 and its downstream effectors); this suppresses autophagy and promotes endoplasmic reticulum and oxidative stress and mitochondrial dysfunction, thereby undermining the health of diabetic cardiomyocytes. The hyperinsulinemia of diabetes may also activate sodium-hydrogen exchangers in cardiomyocytes (leading to injury and loss) and in the proximal renal tubules (leading to sodium retention). Diabetes may cause epicardial adipose tissue expansion, and the resulting secretion of proinflammatory adipocytokines onto the adjoining myocardium can lead to coronary microcirculatory dysfunction and myocardial inflammation and fibrosis. Interestingly, sodium-glucose cotransporter 2 (SGLT2) inhibitors-the only class of antidiabetic medication that reduces serious heart failure events-may act to mitigate each of these mechanisms. SGLT2 inhibitors up-regulate sirtuin-1 and its downstream effectors and autophagic flux, thus explaining the actions of these drugs to reduce oxidative stress, normalize mitochondrial structure and function, and mute proinflammatory pathways in the stressed myocardium. Inhibition of SGLT2 may also lead to a reduction in the activity of sodium-hydrogen exchangers in the kidney (leading to diuresis) and in the heart (attenuating the development of cardiac hypertrophy and systolic dysfunction). Finally, SGLT2 inhibitors reduce the mass and mute the adverse biology of epicardial adipose tissue (and reduce the secretion of leptin), thus explaining the capacity of these drugs to mitigate myocardial inflammation, microcirculatory dysfunction, and fibrosis, and improve ventricular filling dynamics. The pathophysiological mechanisms by which SGLT2 inhibitors may benefit heart failure likely differ depending on ejection fraction, but each represents interference with distinct pathways by which hyperinsulinemia may adversely affect cardiac structure and function.

GLP-1 mediated diuresis and natriuresis are blunted in heart failure and restored by selective afferent renal denervation

Background

Glucagon-like peptide-1 (GLP-1) induces diuresis and natriuresis. Previously we have shown that GLP-1 activates afferent renal nerve to increase efferent renal sympathetic nerve activity that negates the diuresis and natriuresis as a negative feedback mechanism in normal rats. However, renal effects of GLP-1 in heart failure (HF) has not been elucidated. The present study was designed to assess GLP-1-induced diuresis and natriuresis in rats with HF and its interactions with renal nerve activity.

Methods

HF was induced in rats by coronary artery ligation. The direct recording of afferent renal nerve activity (ARNA) with intrapelvic injection of GLP-1 and total renal sympathetic nerve activity (RSNA) with intravenous infusion of GLP-1 were performed. GLP-1 receptor expression in renal pelvis, densely innervated by afferent renal nerve, was assessed by real-time PCR and western blot analysis. In separate group of rats after coronary artery ligation selective afferent renal denervation (A-RDN) was performed by periaxonal application of capsaicin, then intravenous infusion of GLP-1-induced diuresis and natriuresis were evaluated.

Results

In HF, compared to sham-operated control; (1) response of increase in ARNA to intrapelvic injection of GLP-1 was enhanced (3.7 ± 0.4 vs. 2.0 ± 0.4 µV s), (2) GLP-1 receptor expression was increased in renal pelvis, (3) response of increase in RSNA to intravenous infusion of GLP-1 was enhanced (132 ± 30% vs. 70 ± 16% of the baseline level), and (4) diuretic and natriuretic responses to intravenous infusion of GLP-1 were blunted (urine flow 53.4 ± 4.3 vs. 78.6 ± 4.4 µl/min/gkw, sodium excretion 7.4 ± 0.8 vs. 10.9 ± 1.0 µEq/min/gkw). A-RDN induced significant increases in diuretic and natriuretic responses to GLP-1 in HF (urine flow 96.0 ± 1.9 vs. 53.4 ± 4.3 µl/min/gkw, sodium excretion 13.6 ± 1.4 vs. 7.4 ± 0.8 µEq/min/gkw).

Conclusions

The excessive activation of neural circuitry involving afferent and efferent renal nerves suppresses diuretic and natriuretic responses to GLP-1 in HF. These pathophysiological responses to GLP-1 might be involved in the interaction between incretin-based medicines and established HF condition. RDN restores diuretic and natriuretic effects of GLP-1 and thus has potential beneficial therapeutic implication for diabetic HF patients.

Heart rate increases in liraglutide treated chronic heart failure patients: association with clinical parameters and adverse events

Background. Liraglutide, a glucagon-like peptide-1 agonist, is used for treatment of type 2 diabetes and has beneficial cardiovascular properties. However, treatment increases heart rate (HR) and possibly the risk of cardiovascular events in chronic heart failure (CHF) patients. We investigated potential associations between HR changes and clinical, laboratory and echocardiographic parameters and clinical events in liraglutide treated CHF patients. Methods. This was a sub-study of the LIVE study. CHF patients (N = 241) with a left ventricular ejection fraction ≤45% were randomised to 1.8 mg liraglutide daily or placebo for 24 weeks. Electrocardiograms (N = 117) and readouts from cardiac implanted electronic devices (N = 20) were analysed for HR and arrhythmias. Results. In patients with sinus rhythm (SR), liraglutide increased HR by 8 ± 9 bpm (pulse measurements), 9 ± 9 bpm (ECG measurements) and 9 ± 6 bpm (device readouts) versus placebo (all p<.005). Increases in HR correlated with liraglutide dose (p=.01). HR remained unchanged in patients without SR. Serious cardiac adverse events were not associated with HR changes. Conclusions. During 6 months of treatment, HR increased substantially in CHF patients with SR treated with liraglutide but was not associated with adverse events. The long-term clinical significance of increased HR in liraglutide treated CHF patients needs to be determined.

Contrasting effects on the risk of macrovascular and microvascular events of antihyperglycemic drugs that enhance sodium excretion and lower blood pressure

Three classes of anti-hyperglycaemic medications are distinguished by their urinary sodium excretion-enhancing and blood pressure-lowering actions: long-acting glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter-2 inhibitors. Yet, these drugs exert different effects on macrovascular risk. Glucagon-like peptide-1 receptor agonists reduce atherosclerotic thromboembolic events, but have little effect on heart failure; sodium-glucose co-transporter-2 inhibitors decrease the occurrence of heart failure, but have minimal effect on myocardial infarction and stroke; and dipeptidyl peptidase-4 inhibitors do not ameliorate either atherosclerotic thromboembolic events or heart failure. Similarly, the three classes of drugs differ in their early effects on renal function. Dipeptidyl peptidase-4 inhibitors produce a small decrease in renal function that persists for the duration of treatment, and they do not prevent serious adverse renal events. For glucagon-like peptide-1 receptor agonists, a small early decrease in renal function persists for 2 years and is superseded by a small improvement in renal function, with no effect on renal outcomes. In contrast, an initial decrease in glomerular filtration with sodium-glucose co-transporter-2 inhibitors persists for only 1 year and is superseded by a durable improvement in renal function and a reduced risk of serious adverse renal events. These differences may be related to different actions on the proximal tubular reabsorption of sodium, and thereby, on glomerular hyperfiltration. Anti-hyperglycaemic drugs that have natriuretic actions differ markedly in their ability to modulate macrovascular and microvascular risk. These contrasting profiles cannot be predicted by their effects on blood glucose or blood pressure.

Prevalent and Incident Heart Failure in Cardiovascular Outcome Trials of Patients With Type 2 Diabetes

Despite multiple examples of glucose-lowering therapies affecting heart failure (HF) risk, ascertainment of HF data in cardiovascular outcome trials of these medications has not been systematically characterized. In this review, large (n >1,000) published phase III and IV cardiovascular outcome trials evaluating glucose-lowering therapies through June 2017 were identified. Data were abstracted from publications, U.S. Food and Drug Administration advisory committee records, and U.S. Food and Drug Administration labeling documents. Overall, 21 trials including 152,737 patients were evaluated. Rates and definitions of baseline HF and incident HF were inconsistently provided. Baseline ejection fraction data were provided in 3 studies but not specific to patients with HF. No trial reported functional class, ejection fraction, or HF therapy at the time of incident HF diagnosis. HF hospitalization data were available in 15 trials, but only 2 included HF-related events within the primary composite endpoint. This systematic review highlights gaps in HF data capture within cardiovascular outcome trials of glucose-lowering therapies and outlines rationale and strategies for improving HF characterization.

Are the effects of drugs to prevent and to treat heart failure always concordant? The statin paradox and its implications for understanding the actions of antidiabetic medications

Most treatments for chronic heart failure are effective both in preventing its onset and reducing its progression. However, statins prevent the development of heart failure, but they do not decrease morbidity and mortality in those with established heart failure. This apparent discordance cannot be explained by an effect to prevent interval myocardial infarctions. Instead, it seems that the disease that statins were preventing in trials of patients with a metabolic disorder was different from the disease that they were treating in trials of chronic heart failure. The most common phenotype of heart failure in patients with obesity and diabetes is heart failure with a preserved ejection fraction (HFpEF). In this disorder, the anti-inflammatory effects of statins might ameliorate myocardial fibrosis and cardiac filling abnormalities, but these actions may have little relevance to patients with heart failure and a reduced ejection fraction (HFrEF), whose primary derangement is cardiomyocyte loss and stretch. These distinctions may explain why statins were ineffective in trials that focused on HFrEF, but have been reported to produce favourable effects in observational studies of HFpEF. Similarly, selective cytokine antagonists were ineffective in HFrEF, but have been associated with benefits in HFpEF. These observations may have important implications for our understanding of the effects of antihyperglycaemic medications. Glucagon-like peptide-1 receptor agonists have had neutral effects on heart failure events in people at risk for HFpEF, but have exerted deleterious actions in HFrEF. Similarly, sodium-glucose co-transporter 2 inhibitors, which exert anti-inflammatory effects and reduce heart failure events in patients who are prone to HFpEF, may not be effective in HFrEF. The distinctions between HFrEF and HFpEF may explain why the effects of drugs on heart failure events in diabetes trials may not be relevant to their use in patients with systolic dysfunction.

Obesity-Related Heart Failure With a Preserved Ejection Fraction: The Mechanistic Rationale for Combining Inhibitors of Aldosterone, Neprilysin, and Sodium-Glucose Cotransporter-2

Obesity-related heart failure with a preserved ejection fraction (HFpEF) is an important phenotype prevalent in the community, especially in people with metabolic disorders (e.g., dyslipidemia, diabetes). These individuals exhibit a marked expansion of plasma volume, but ventricular distensibility is limited, most likely as a result of cardiac microvascular rarefaction acting in concert with myocardial and pericardial fibrosis. Consequently, the increase in plasma volume causes a disproportionate increase in cardiac filling pressures, leading to heart failure, even though systolic ejection is not impaired. The features of this syndrome appear to be related (in part) to the overproduction of adipocyte-derived cell-signaling molecules, including aldosterone and neprilysin. The resulting sodium retention and plasma volume expansion is exacerbated by their mutual actions to promote cardiac and systemic inflammation and fibrosis. Inhibitors of aldosterone, neprilysin, and the sodium-glucose transporter-2 (SGLT2) can ameliorate the plasma volume expansion and pro-inflammatory and profibrotic pathways, potentially opposing the action of diverse adipocytokines. All 3 classes of drugs can reduce the quantity of visceral adipose tissue and ameliorate its abnormal biological properties. This mechanistic framework is supported by the results of large-scale randomized trials with mineralocorticoid receptor antagonists and SGLT2 inhibitors and is being further tested in an ongoing large-scale trial of neprilysin inhibition. The promise of using mineralocorticoid receptor antagonists, neprilysin inhibitors, and SGLT2 inhibitors (alone or in combination) in the management of obesity-related HFpEF suggests that physicians might finally have a phenotype of HFpEF that they can understand and treat.