Effect of Liraglutide on Cardiovascular Function and Myocardial Tissue Characteristics in Type 2 Diabetes Patients of South Asian Descent Living in the Netherlands: A Double-Blind, Randomized, Placebo-Controlled Trial

Evolution of myocardial steatosis in high cardiovascular risk T2DM patients treated by GLP1 receptor agonists: LICAS study

BACKGROUND

We hypothesized that the reduction of intramyocardial fat content may be involved in the cardioprotective effect of glucagon-like peptide-1 receptor agonists (GLP1-RA) in patients with type 2 diabetes (T2D). Therefore, we aimed to evaluate the change in intramyocardial triglyceride content in T2D patients treated with GLP1-RA.

METHODS

This monocentric proof-of-concept cohort study included patients with unbalanced T2D prior to the introduction of GLP1-RA. Patients underwent cardiac magnetic resonance imaging (MRI) coupled with nuclear magnetic resonance (NMR) spectroscopy at baseline and six months after the introduction (M6) of a GLP1-RA to assess changes in intramyocardial triglyceride levels and morphological, functional, and cardiac tissue parameters. The relative delta (Δr) between baseline and M6 was calculated and analyzed by Student test or sign test.

RESULTS

Twenty-six patients (mean age = 62.2 ± 6.7 years, median HbA1c = 9.1 %) fulfilled inclusion criteria and had both NMR measures. Compared with baseline, relative intramyocardial triglyceride levels significantly decreased after six months of treatment (mean Δr = -26 % [95 %CI:-39; -13]p = 0.003), as well as glycated hemoglobin (HbA1c) (median Δr = -26 % [IQR:25], p < 0.0001), body mass index (BMI) (mean Δr = -6% [-9; -4], p < 0.0001) and left ventricular mass (mean Δr = -6 [-12; -1] p = 0.02). The relative evolution of intramyocardial triglyceride content was not correlated with the relative evolution of HbA1c (r = 0.10) and BMI (r = -0.02).

CONCLUSIONS

We demonstrate a significant reduction in intramyocardial triglyceride content in patients with T2D after six months of treatment with GLP1-RA. The lack of correlation with reductions in HbA1c and BMI suggests a specific effect of GLP1-RA on myocardial steatosis, which might contribute to their previously demonstrated cardiovascular benefits.

Systematic Review of Left Ventricular Remodeling in Response to Hypoglycemic Medications: Assessing Changes in End-Systolic and End-Diastolic Diameters

Hypoglycemic medications are widely used in managing diabetes mellitus, with emerging evidence suggesting their role in cardiac reverse remodeling. This systematic review aims to quantitatively synthesize data regarding the impact of these medications on left ventricular end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD), and to evaluate the clinical relevance of these changes in promoting favorable cardiac outcomes. We conducted a comprehensive search across PubMed, Scopus, and the Web of Science up to 22 April 2024, selecting studies based on inclusion criteria that focused on the impact of hypoglycemic medications on LVEDD and LVESD in patients with diabetes. Studies were selected through a rigorous process, adhering to PRISMA guidelines, and involving various designs including randomized controlled trials and observational studies. The main outcomes were changes in LVEDD and LVESD measured by validated cardiac imaging techniques. A total of ten studies met the inclusion criteria, involving a total of 1180 patients. Treatment durations ranged from 3 to 24 months. Significant improvements in cardiac dimensions were noted with some medications. For instance, Liraglutide treatment over three months significantly improved LVEF from 47.2% to 57.2% and reduced LVEDD and LVESD from 46.5 mm to 45.2 mm and 35.2 mm to 32.7 mm, respectively. In contrast, other medications like Sitagliptin showed minimal impact over 24 months. On average, hypoglycemic medications reduced LVEDD from 58.2 mm to 55.0 mm and LVESD from 48.3 mm to 44.3 mm, with a mean improvement in LVEF from 38.9% to 43.8%. Hypoglycemic medications contribute variably to cardiac reverse remodeling. Medications such as Liraglutide and Dapagliflozin demonstrate significant potential in improving cardiac dimensions and function, indicating their utility beyond glycemic control. This review highlights the need for tailored treatment approaches to maximize cardiac outcomes in patients with diabetes, suggesting a broader therapeutic role for these agents.

The effect of SGLT2 inhibitors and GLP1 receptor agonists on arterial stiffness: A meta-analysis of randomized controlled trials

BACKGROUND

Pulse wave velocity (PWV) and augmentation index (AIx) are indices used to assess arterial stiffness. We evaluated the effect of sodium glucose co-transporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 receptor agonists (GLP1-RA) on arterial stiffness indices.

METHODS

We searched PubMed (up to January 2024) for RCTs assessing the effect of SGLT2i or GLP1-RA on arterial stiffness with reporting outcomes PWV and AIx. Effect sizes of the included studies were expressed as weighted mean difference (WMD) and 95 % confidence interval. Subgroup analyses were performed based on comparator (placebo vs. active comparator), design (RCT vs. crossover), population (diabetic vs. all) and blindness (yes vs. no).

RESULTS

A total of 19 studies (SGLT2i, 12 studies; GLP1-RA, 5 studies; SGLT2i/GLP1-RA combination, 2 studies) assessing 1212 participants were included. We did not find any statistically significant association between GLP1-RA or SGLT2i and PWV or AIx. None of the subgroup analyses showed any statistically significant result.

CONCLUSION

No evidence of a favorable change in arterial stiffness indices (PWV, AIx) was found following the administration of SGLT2i or GLP1-RA.

Unraveling the Cardiac Matrix: From Diabetes to Heart Failure, Exploring Pathways and Potential Medications

Myocardial infarction (MI) often leads to heart failure (HF) through acute or chronic maladaptive remodeling processes. This establishes coronary artery disease (CAD) and HF as significant contributors to cardiovascular illness and death. Therefore, treatment strategies for patients with CAD primarily focus on preventing MI and lessening the impact of HF after an MI event. Myocardial fibrosis, characterized by abnormal extracellular matrix (ECM) deposition, is central to cardiac remodeling. Understanding these processes is key to identifying new treatment targets. Recent studies highlight SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1-RAs) as favorable options in managing type 2 diabetes due to their low hypoglycemic risk and cardiovascular benefits. This review explores inflammation's role in cardiac fibrosis and evaluates emerging anti-diabetic medications' effectiveness, such as SGLT2i, GLP1-RAs, and dipeptidyl peptidase-4 inhibitors (DPP4i), in preventing fibrosis in patients with diabetes post-acute MI. Recent studies were analyzed to identify effective medications in reducing fibrosis risk in these patients. By addressing these areas, we can advance our understanding of the potential benefits of anti-diabetic medications in reducing cardiac fibrosis post-MI and improve patient outcomes in individuals with diabetes at risk of HF.

The effect of glucagon-like peptide-1 receptor agonists on cardiac function and structure in patients with or without type 2 diabetes mellitus: An updated systematic review and meta-analysis

AIMS

To conduct an updated systematic review and meta-analysis to evaluate the efficacy of glucagon-like peptide-1 receptor agonists (GLP-1RAs) with regard to cardiac function and structure in people with or without type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

We conducted a systematic search using the PubMed, Embase and ClinicalTrials.gov online databases. The primary outcome of interest was changes in mitral inflow E-velocity to tissue Doppler e' velocity (E/e') ratio. Secondary outcomes included other indicators of cardiac reverse remodelling and functional capacity comprising changes in left ventricular mass (LVM), left ventricular global longitudinal strain, left ventricular end-diastolic volume, left ventricular end-systolic volume, left ventricular ejection fraction (LVEF), early to atrial mitral inflow velocity ratio, left atrial volume (LAV), N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and 6-min walk test (6MWT) results.

RESULTS

A total of 15 trials involving 898 patients were included in this analysis. GLP-1RAs significantly improved E/e' ratio (mean difference [MD] = -0.73; 95% confidence interval [CI] -1.34, -0.13), LVM (MD = -3.86 g; 95% CI -7.60, -0.12), LAV (MD = -8.20 mL; 95% CI -12.37, -4.04), NT-proBNP level (standardized MD = -0.27; 95% CI -0.47, -0.06), and 6MWT result (MD = +22.31 m; 95% CI 1.64, 42.99). However, GLP-1RAs had no effect on LVEF (MD = +0.31%; 95% CI -1.02, 1.64).

CONCLUSIONS

In this systematic review and meta-analysis, GLP-1RAs were found to have a positive impact on left ventricle diastolic function, hypertrophy, and exercise capacity, but had no effect on systolic function.

Separate and combined effects of empagliflozin and semaglutide on vascular function: A 32-week randomized trial

AIM

Despite the increasing use of combination treatment with sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide-1 receptor agonists, data are limited on the effects of combination treatment on markers of cardiovascular disease. This study aimed to investigate the effect of empagliflozin, semaglutide, and their combination on vascular function.

MATERIALS AND METHODS

In total, 120 patients with type 2 diabetes were randomized into four groups (n = 30 in each) for 32 weeks: placebo, semaglutide, empagliflozin, and their combination. The study had two co-primary outcomes: change in arterial stiffness and kidney oxygenation. This paper reports on arterial stiffness assessed as carotid-femoral pulse wave velocity. Secondary outcomes included 24-h blood pressure (BP), 24-h central BP, urinary albumin to creatinine ratio and glycaemic control assessed by both continuous glucose monitoring and glycated haemoglobin.

RESULTS

The carotid-femoral pulse wave velocity did not change significantly in any of the groups compared with placebo. Twenty-four-hour systolic BP was reduced by 10 mmHg (95% CI 6-14), p < .001 in the combination group, significantly superior to both placebo and monotherapy (p < .05). Combination treatment increased glycaemic time in range from 72% at baseline to 91% at week 32, p < .001, without increasing time below range. The urinary albumin to creatinine ratio decreased by 36% (95% CI 4-57), p = .03 in the combination group compared with placebo.

CONCLUSIONS

Empagliflozin, semaglutide, or their combination did not reduce arterial stiffness. Combination treatment showed a substantial and clinically important reduction in 24-h systolic BP compared with either treatment alone. Combination treatment increased glycaemic time in range without increasing the risk of hypoglycaemia.

The latest emerging drugs for the treatment of diabetic cardiomyopathy

INTRODUCTION

Diabetic cardiomyopathy (DCM) is a serious complication of diabetes mellitus involving multiple pathophysiologic mechanisms. In addition to hypoglycemic agents commonly used in diabetes, metabolism-related drugs, natural plant extracts, melatonin, exosomes, and rennin-angiotensin-aldosterone system are cardioprotective in DCM. However, there is a lack of systematic summarization of drugs for DCM.

AREAS COVERED

In this review, the authors systematically summarize the most recent drugs used for the treatment of DCM and discusses them from the perspective of DCM pathophysiological mechanisms.

EXPERT OPINION

We discuss DCM drugs from the perspective of the pathophysiological mechanisms of DCM, mainly including inflammation and metabolism. As a disease with multiple pathophysiological mechanisms, the combination of drugs may be more advantageous, and we have discussed some of the current studies on the combination of drugs.

Effects of Glucagon-Like Peptide-1 Receptor Agonist (GLP-1RA) on Cardiac Structure and Function: A Systematic Review and Meta-Analysis of Randomized-Controlled Trials

PURPOSE

Recent trials suggest glucagon-like peptide-1 receptor agonists (GLP-1RAs) may have a cardioprotective role by reducing major adverse cardiac events, stroke mortality and heart failure-related hospitalisations. We examined whether and how GLP-1RAs affect cardiac function in cardiovascular and metabolic diseases including type 2 diabetes, heart failure and post-myocardial infarction.

METHODS

In this PRISMA-adherent systematic review and meta-analysis, three databases were searched from inception to July 2021 and registered on PROSPERO (CRD42021259661).

RESULTS

20 reports of 19 randomized placebo-controlled trials including 2062 participants were meta-analyzed. Among type 2 diabetes patients, GLP-1RA resulted in improved systolic function measured by circumferential strain (mean difference [MD]= -5.48; 95% CI: -10.47 to -0.49; P= 0.03; I2= 89%) and diastolic dysfunction measured by E / A (MD= -0.15; 95% CI: -0.25 to -0.05; P= 0.003; I2= 0%). For post-myocardial infarction patients, GLP-1RA reduced infarct size (g) (MD= -5.36; 95% CI: -10.68 to -0.04; P= 0.05; I2= 78%). Liraglutide, but not exenatide, demonstrated improved systolic function, by increasing left ventricular ejection fraction (MD= 4.89; 95% CI: 3.62 to 6.16; P< 0.00001; I2= 0%) and reducing left ventricular end-systolic volume (MD= -4.15; 95% CI: -7.49 to -0.81; P = 0.01; I2= 0%). Among heart failure patients, no significant changes were noted.

CONCLUSION

GLP-1RA drugs may improve systolic and diastolic function in type 2 diabetes and reduce infarct size post-acute myocardial infarction with no demonstrable effect on cardiac function in heart failure. Tailored recommendations for the use of GLP-1RAs for cardioprotection should be considered for each patient's condition.

Effect of liraglutide on cardiac function in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of double-blind, randomized, placebo-controlled trials

BACKGROUND

Liraglutide widely utilized in type 2 diabetes treatment, has elicited conflicting findings regarding its impact on cardiac function in patients with this condition. Therefore, The objective of this study was to conduct a meta-analysis of randomized controlled trials (RCTs) to evaluate the effects of liraglutide on cardiac function in patients diagnosed with type 2 diabetes.

METHODS

We identified double-blind randomized trials assessing the effects of liraglutide compared to placebo on cardiac function in patients with type 2 diabetes. Data were synthesized with the fixed-effect models to generate standard mean differences (SMDs) with 95% confidence intervals (CIs) of each outcome for liraglutide versus placebo. The risk of bias would be assessed according to the Cochrane Risk of Bias Tool, while meta-analysis would be conducted using Revman 5.3.0 software. The evidence was graded based on the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

The meta-analysis encompassed 5 RCTs including 220 participants. Results revealed that liraglutide exhibited significant enhancements in left ventricular ejection fraction [SMD = -0.38, 95%CI(-0.70, -0.06), P = .02], cardiac index [SMD = -1.05, 95%CI(-1.52, -0.59), P < .0001], stroke volume [SMD = -0.67, 95%CI(-1.02, -0.32), P = .0002] and early diastolic filling velocity/late atrial filling velocity ratio [SMD = -0.52, 95%CI(-0.82, -0.22), P = .0006]. However, no statistically significant impact on cardiac output [SMD = -0.20, 95%CI(-0.53, 0.14), P = .26], early diastolic filling velocity/early diastolic annular velocity (E/Ea) ratio [SMD = -0.34, 95%CI(-0.75, 0.06), P = .10] and early diastolic filling velocity/early diastolic mitral annular velocity ratio [SMD = 0.21, 95%CI(-0.15, 0.56), P = .25] was observed. The Grading of Recommendations Assessment, Development and Evaluation evidence quality ratings indicated that all the outcome measures included in this study were evaluated as having low and very low quality.

CONCLUSION

The available evidence suggested that liraglutide may exert a favorable impact on cardiac function in patients with type 2 diabetes. Consequently, the utilization of liraglutide as a preventive measure against heart failure incidents in individuals with type 2 diabetes represents a promising strategy. However, robust evidence support requires the conduct of large-scale, multicenter high-quality RCTs.

Myocardial steatosis across the spectrum of human health and disease

Preclinical data strongly suggest that myocardial steatosis leads to adverse cardiac remodelling and left ventricular dysfunction. Using 1 H cardiac magnetic resonance spectroscopy, similar observations have been made across the spectrum of health and disease. The purpose of this brief review is to summarize these recent observations. We provide a brief overview of the determinants of myocardial triglyceride accumulation, summarize the current evidence that myocardial steatosis contributes to cardiac dysfunction, and identify opportunities for further research.

Effects of first-line antidiabetic drugs on the improvement of arterial stiffness: A Bayesian network meta-analysis

BACKGROUND

Changes in vascular function are closely associated with the development of cardiovascular disease (CVD). Pulse wave velocity (PWV) is a potential indicator of vascular dysfunction; it allows noninvasive assessment of arterial stiffness. Currently, evidence for the effects of different classes of antidiabetic drugs on arterial stiffness remains limited. In this study, a network meta-analysis (NMA) was performed to explore the associations between changes in arterial stiffness and first-line antidiabetic drugs by evaluating PWV in patients with different metabolic abnormalities.

METHODS

We systematically searched several electronic databases for randomized controlled trials (RCTs) published from inception until 25 August 2022, without language restrictions. The primary outcome was the change in PWV (ΔPWV) in all included studies; subgroup analysis was performed for patients with abnormal glucose metabolism, including prediabetes and diabetes mellitus. NMA was performed to calculate the mean differences (MDs) with 95% confidence intervals (CIs) as effect sizes to evaluate the ΔPWV.

RESULTS

Among the 2257 candidate articles identified in the initial search, 18 RCTs were eventually included in the analysis. In all studies, two classes of new antidiabetic drugs, glucagon-like peptide-1 receptor (GLP-1R) agonists and sSodium-glucose co-transporter 2 (SGLT-2) inhibitors, improved arterial stiffness by decreasing PWV compared with placebo (MD = -1.11, 95% CI: -1.94 to 0.28) and (MD = -0.76, 95% CI: -1.45 to -0.08). A conventional antidiabetic drug, metformin, also showed similar efficacy compared with placebo (MD = -0.73, 95% CI: -1.33 to -0.12). Finally, in subgroup studies of patients with abnormal glucose metabolism diseases, GLP-1R agonists (MD = -1.06, 95% CI: -2.05 to -0.10) significantly decreased PWV compared with placebo.

CONCLUSION

Three classes of antidiabetic drugs-GLP-1R agonists, SGLT-2 inhibitors, and metformin-have the potential to improve arterial stiffness. Among the six classes of antidiabetic drugs analyzed, GLP-1R agonists constitute the only class of drugs that improves arterial stiffness in patients with abnormal glucose metabolism diseases.

The Impact of Glucagon-Like Peptide-1 Receptor Agonist on the Cardiovascular Outcomes in Patients With Type 2 Diabetes Mellitus: A Meta-Analysis and Systematic Review

Background

Since 2005, the cardioprotective effects of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) have garnered attention. The cardioprotective effect could be an added benefit to the use of GLP-1 RA. This systematic review and meta-analysis aimed at summarizing observational studies that recruited type 2 diabetes individuals with fewer cardiovascular (CV) events before enrolling in the research.

Methods

Systematically, the databases were searched for observational studies reporting compound CV events and deaths in type 2 diabetics without having the risk of cardiovascular diseases (CVDs) compared to other glucose-lowering agents. A meta-analysis was carried out using random effects model to estimate the overall hazard ratio (HR) with a 95% confidence interval (CI). Five studies were found eligible for the systematic review including a total of 64,452 patients receiving either liraglutide (three studies) or exenatide (two studies).

Results

The pooled HR for major adverse cardiac event (MACE) and extended MACE was 0.72 (95% CI: 0.65 - 0.93, I2 = 68%) and 0.93 (95% CI: 0.89 - 0.98, I2 = 29%), respectively. The pooled HR for hospitalization due to heart failure (HHF) and occurrence of HF was 0.84 (95% CI: 0.77 - 0.91, I2 = 79%) and 0.83 (95% CI: 0.75 - 0.94, I2 = 95%), respectively. For stroke, GLP-1 RA was associated with a significant risk reduction of 0.86 (95% CI: 0.75 - 0.98, I2 = 81%). There was no significant myocardial infarction (MI) risk reduction with GLP-1 RA. As for all-cause mortality, the pooled HR for the occurrence of all-cause mortality was 0.82 (95% CI: 0.76 - 0.88, I2 = 0%). The pooled HR for the occurrence of CV death was 0.75 (95% CI: 0.65 - 0.85, I2 = 38%). GLP-1 RA therapy was associated with a significantly low risk of MACE, extended MACE, all-cause mortality, and CV mortality. Except for MACE, the heterogenicity among the studies was low.

Conclusion

We conclude that GLP-1 RA is associated with a low risk of CV events composites and mortality. The findings support the cardioprotective effect of GLP-1 RA.

Effect of Liraglutide on Cardiac Function in Individuals With Type 2 Diabetes: A Meta-Analysis

The aim of this study was to determine the effect of liraglutide on cardiac function in individuals with type 2 diabetes. The present meta-analysis aimed to identify studies testing liraglutide in individuals with type 2 diabetes. We included observational and randomized controlled trials comparing liraglutide with placebo or any other drug alone or in combination with other drugs. A comprehensive search was carried out using online databases including PubMed, Google Scholar, and Cochrane Library to find relevant studies from inception to June 30, 2023, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Key terms used to search for relevant studies included "liraglutide," "cardiac function," and "type 2 diabetes," along with their synonyms and Medical Subject Heading (MeSH) terms. The outcomes assessed in the present meta-analysis included diastolic cardiac function and systolic cardiac function. For diastolic cardiac function, we assessed the E to A (E/A) ratio and the E to Ea (E/Ea) ratio. To assess the impact of liraglutide on systolic function, we assessed stroke volume in mL, left ventricular ejection fraction (LVEF) in %, cardiac output in L/min, and cardiac index in L/min/m². A total of seven studies were included, with a pooled sample size of 307 individuals (160 in the liraglutide group and 147 in the control group). The results indicated that liraglutide significantly reduced the E/A ratio (mean difference [MD]: -0.22, 95% CI: -0.38 to -0.06, p-value: 0.008) and E/Ea ratio (MD: -0.76, 95% confidence interval (CI): -1.39 to -0.12, p-value: 0.02, suggesting a potential clinical benefit on ventricular diastolic function. However, there was no significant impact on LVEF (MD: 0.46, 95% CI: -3.13 to 4.05, p-value: 0.80), cardiac output (MD: 0.05, 95% CI: -0.39 to 0.49), cardiac index (MD: 0.07, 95% CI: -0.18 to 0.32), and stroke volume (MD: -5.34, 95% CI: -14.81 to 4.12), indicating that liraglutide did not improve systolic function.

The effect of SGLT2 inhibitors, GLP1 agonists, and their sequential combination on cardiometabolic parameters: A randomized, prospective, intervention study

BACKGROUND

Pulse wave velocity (PWV) and augmentation index (AIx) are indices used to assess arterial stiffness. We aim to compare the effect of empagliflozin, liraglutide and their sequential combination on arterial stiffness indices in patients with type 2 diabetes (T2D).

METHODS

This was a randomized single blind study evaluating the effect of empagliflozin vs liraglutide in adult patients with T2D. Patients were randomized to liraglutide titrated gradually to 1.8 mg or empagliflozin 25 mg in 1:1 ratio. Three months later empagliflozin was added to the liraglutide group, and liraglutide was added to the empagliflozin group. Patients were assessed with non-invasive tests for arterial stiffness (i.e., carotid-femoral PWV and AIx of aortic pressure) at baseline, 3-month and 9-month visits (final visit was extended for 3 months from the initial design due to Covid 19 pandemic). The primary outcome was the between-group difference of PWV change (ΔPWV) and ΔAIx at 3 months. Secondary outcomes included the between-group difference of ΔPWV and ΔAIx at 9 months, as well as the ΔPWV and ΔAIx between baseline and 9-month visit when total study population was assessed.

RESULTS

A total of 62 patients with T2D (30 started liraglutide; 32 empagliflozin, mean age 63 years, 25 % with established cardiovascular disease) participated in the study. We failed to show any significant between-group differences of ΔPWV and ΔΑΙx at 3 and 9 months, as well as between-group difference of ΔPWV and ΔAIx for the total study population between baseline and 9-month visit. In contrast, systemic vascular resistance and lipoprotein(a) levels improved, showing better results with liraglutide than empagliflozin. Favorable effects were also observed on body weight, body mass index, body and visceral fat, blood pressure, HbA1c, and uric acid levels.

CONCLUSION

No evidence of a favorable change in arterial stiffness indices was seen with empagliflozin or liraglutide or their combination in this study. Well-designed powerful studies are needed to address any potential effects on arterial stiffness in selected populations.

Effect of Glucagon-like Peptide-1 Receptor Agonists on Prognosis of Heart Failure and Cardiac Function: A Systematic Review and Meta-analysis of Randomized Controlled Trials

PURPOSE

Whether an antidiabetic drug, glucagon-like peptide-1 receptor agonist (GLP-1RA), could improve the prognosis of heart failure and cardiac function remains controversial. We conducted a systematic review and meta-analysis of randomized controlled trials to explore the influence of GLP-1RAs on heart failure in patients regardless of diabetes diagnosis.

METHODS

Literature in English from the PubMed, EMBASE, and Cochrane Library databases was searched from inception to July 2022. The study aim was to identify published, randomized, placebo-controlled trials testing GLP-1RAs in patients with or without diabetes. Outcomes were heart failure hospitalization, cardiac function, and structure measures.

FINDINGS

Twenty-two randomized controlled trials involving 61,412 patients are included in the meta-analysis. Overall, compared with the placebo group, GLP-1RA treatment could not significantly decrease heart failure hospitalization in patients with a history of heart failure (hazard ratio [HR], 1.07; 95% CI, 0.91 to 1.25; P = 0.422). Six-minute walking test distances (WMD, 19.08 m; 95% CI, 4.81 to 33.36; P = 0.01), E-wave (SMD, -0.40; 95% CI, -0.60 to -0.20; P < 0.001), early diastolic to late diastolic velocities ratio (WMD, -0.10; 95% CI, -0.18 to -0.02; P = 0.01), mitral inflow E velocity to tissue Doppler e' ratio (WMD, -0.97; 95% CI, -1.54 to -0.41; P < 0.001), and E-wave deceleration time (WMD, -9.96 milliseconds; 95% CI, -18.52 to -1.41; P = 0.02) increased significantly after administration of GLP-1RAs. However, GLP-1RAs do not significantly influence N-terminal pro-B-type natriuretic peptide levels (WMD, -20.02 pg/mL; 95% CI, -53.12 to 13.08; P = 0.24), Minnesota Living with Heart Failure Questionnaire quality of life scores (WMD, -1.08; 95% CI, -3.99 to 1.84; P = 0.47), or left ventricular ejection fractions (WMD, -0.37%; 95% CI, -1.19 to 0.46; P = 0.38).

IMPLICATIONS

GLP-1RAs did not reduce heart failure readmissions in patients with a history of heart failure and elevated N-terminal pro-B-type natriuretic peptide levels. Thus, the prognosis of heart failure was not improved, although GLP-1RAs did significantly improve left ventricular diastolic function in patients. PROSPERO identifier: CRD42021226231.

Application of glucagon-like peptide-1 receptor antagonists in fibrotic diseases

Fibrosis can occur in various organs, leading to structural destruction, dysfunction, and even organ failure. Hence, organ fibrosis is being actively researched worldwide. Glucagon-like peptide-1 (GLP-1), a naturally occurring hormone, binds to a G-protein-coupled receptor widely distributed in the pancreas, kidney, lung, heart, gastrointestinal tract, and other organs. Synthetic GLP-1 analogs can be used as GLP-1 receptor agonists (GLP-1RAs) for treating diabetes mellitus. In recent years, GLP-1RAs have also been found to exert anti-inflammatory, antioxidant, and cardiovascular protective effects. GLP-1RAs have also been shown to inhibit fibrosis of solid organs, such as the lung, heart, liver, and kidney. In this review, we discuss the advancements in research on the role of GLP-1RAs in the fibrosis of the heart, lung, liver, kidney, and other organs to obtain new clues for treating organ fibrosis.

Effect of race on cardiometabolic responses to once-weekly exenatide: insights from the Exenatide Study of Cardiovascular Event Lowering (EXSCEL)

Background

To determine whether there were racial differences in short-term cardiometabolic responses to once-weekly exenatide (EQW) in the Exenatide Study of Cardiovascular Event Lowering (EXSCEL).

Methods

EXSCEL enrolled 14,752 patients with type 2 diabetes (hemoglobin A_1c (HbA_1c) 6.5–10.0% [48–86 mmol/mol]) with or without cardiovascular disease who were randomized double-blind to EQW or placebo. Background glucose-lowering/other cardiovascular therapies were unaltered for 6 months post-randomization unless clinically essential, facilitating comparison of EQW-associated effects in 14,665 evaluable participants self-identifying as White (n = 11,113), Asian (n = 1444), Black (n = 870), or Other Race (n = 1,238. Placebo-adjusted 6 month absolute changes in cardiometabolic variables were assessed using generalized linear models.

Results

Mean 6-month placebo-adjusted HbA_1c reductions were similar in the four groups (range 0.54–0.67% [5.9 to 7.3 mmol/mol], P = 0.11 for race×treatment interaction), with no significant difference in Asians (reference) versus other groups after covariate adjustment (all P ≥ 0.10). Six-month placebo-adjusted mean changes in systolic (−1.8 to 0.0 mmHg) and diastolic (0.2 to 1.2 mmHg) blood pressure, serum LDL (− 0.06 to 0.02 mmol/L) and HDL (0.00 to 0.01 mmol/L) cholesterol, and serum triglycerides (−0.1 to 0.0 mmol/L) were similar in the racial groups (P ≥ 0.19 for race×treatment interaction and all P ≥ 0.13 for comparisons of Asians with other races). Resting pulse rate increased more in Asians (4 beats/min) than in other groups (≤ 3 beats/min, P = 0.016 for race×treatment interaction and all P ≤ 0.050 for comparisons of Asians with other races).

Conclusions

Short-term cardiometabolic responses to EQW were similar in the main racial groups in EXSCEL, apart from a greater pulse rate increase in Asians.

Trial registration: https://clinicaltrials.gov NCT01144338.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01555-z.

Diabetes and Myocardial Fibrosis: A Systematic Review and Meta-Analysis

OBJECTIVES

This systematic review and meta-analysis investigated the association of diabetes and glycemic control with myocardial fibrosis (MF).

BACKGROUND

MF is associated with an increased risk of heart failure, coronary artery disease, arrhythmias, and death. Diabetes may influence the development of MF, but evidence is inconsistent.

METHODS

The authors searched EMBASE, Medline Ovid, Cochrane CENTRAL, Web of Science, and Google Scholar for observational and interventional studies investigating the association of diabetes, glycemic control, and antidiabetic medication with MF assessed by histology and cardiac magnetic resonance (ie, extracellular volume fraction [ECV%] and T₁ time).

RESULTS

A total of 32 studies (88% exclusively on type 2 diabetes) involving 5,053 participants were included in the systematic review. Meta-analyses showed that diabetes was associated with a higher degree of MF assessed by histological collagen volume fraction (n = 6 studies; mean difference: 5.80; 95% CI: 2.00-9.59) and ECV% (13 studies; mean difference: 2.09; 95% CI: 0.92-3.27), but not by native or postcontrast T₁ time. Higher glycosylated hemoglobin levels were associated with higher degrees of MF.

CONCLUSIONS

Diabetes is associated with higher degree of MF assessed by histology and ECV% but not by T₁ time. In patients with diabetes, worse glycemic control was associated with higher MF degrees. These findings mostly apply to type 2 diabetes and warrant further investigation into whether these associations are causal and which medications could attenuate MF in patients with diabetes.

Diabetic cardiomyopathy: Clinical phenotype and practice

Diabetic cardiomyopathy (DCM) is a pathophysiological condition of cardiac structure and function changes in diabetic patients without coronary artery disease, hypertension, and other types of heart diseases. DCM is not uncommon in people with diabetes, which increases the risk of heart failure. However, the treatment is scarce, and the prognosis is poor. Since 1972, one clinical study after another on DCM has been conducted. However, the complex phenotype of DCM still has not been fully revealed. This dilemma hinders the pace of understanding the essence of DCM and makes it difficult to carry out penetrating clinical or basic research. This review summarizes the literature on DCM over the last 40 years and discusses the overall perspective of DCM, phase of progression, potential clinical indicators, diagnostic and screening criteria, and related randomized controlled trials to understand DCM better.

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.

Metabolic improvement with short-term, glucagon-like peptide-1 receptor agonist treatment does not improve cardiac diastolic dysfunction in patients with type 2 diabetes: A randomized, double-blind, placebo-controlled trial

AIM

To investigate if short-term treatment with liraglutide, a glucagon-like peptide-1 receptor agonist, improves left ventricular diastolic function.

MATERIALS AND METHODS

An investigator-initiated, double-blind, randomized, placebo-controlled trial on the effect of 18 weeks of treatment with liraglutide on diastolic function was assessed in patients with type 2 diabetes with signs of diastolic dysfunction (echo-Doppler determined E/e' ≥ 9 and/or lateral e' ≤ 10 cm/s). Primary outcomes were improved left ventricle filling (the early peak filling rate [ePFR]) and left atrium ease of emptying (the passive emptying fraction [LA_PEF ]), assessed by cardiac magnetic resonance imaging at rest and during chronotropic stress. Secondary outcomes included left ventricular and left atrial volumes and systolic function, measures of aortic stiffness and echocardiographic diastolic variables.

RESULTS

Forty patients were randomized to liraglutide subcutaneously 1.8 mg/day (n = 20) or placebo (n = 20). Liraglutide reduced HbA1c (-0.47%, 95% CI [-0.88% to -0.06%] [-5.1, 95% CI {-9.7 to -0.62} mmol/mol]) and weight (-2.9, 95% CI [-4.6 to -1.2] kg); both P < .03. Liraglutide did not change ePFR at rest (-24 ± 60 vs. -6 ± 46 mL/s), during stress (2 ± 58 vs. -2 ± 38 mL/s), or the changes from rest to stress (12.9 ± 72.5 vs. 4.7 ± 104.0; all P > .05). LA_PEF decreased with liraglutide during stress (-3.1% [-9.0%, 1.1%] vs. 1.0% [-2.9%, 6.1%]; P = .049), but no changes were evident at rest (-4.3% [-7.9%, 1.9%] vs. -0.6% [-3.1%, 2.2%]; P = .19), or for the changes from rest to stress (-1.7 ± 8.4 vs. 0.8 ± 8.2; P = .4). Secondary outcomes were unchanged by liraglutide.

CONCLUSIONS

Short-term treatment with liraglutide did not improve left ventricular diastolic function, suggesting the cardioprotective effect is not exerted through the improvement in diastolic dysfunction.

Therapeutic and diagnostic targeting of fibrosis in metabolic, proliferative and viral disorders

Fibrosis is a common denominator in many pathologies and crucially affects disease progression, drug delivery efficiency and therapy outcome. We here summarize therapeutic and diagnostic strategies for fibrosis targeting in atherosclerosis and cardiac disease, cancer, diabetes, liver diseases and viral infections. We address various anti-fibrotic targets, ranging from cells and genes to metabolites and proteins, primarily focusing on fibrosis-promoting features that are conserved among the different diseases. We discuss how anti-fibrotic therapies have progressed over the years, and how nanomedicine formulations can potentiate anti-fibrotic treatment efficacy. From a diagnostic point of view, we discuss how medical imaging can be employed to facilitate the diagnosis, staging and treatment monitoring of fibrotic disorders. Altogether, this comprehensive overview serves as a basis for developing individualized and improved treatment strategies for patients suffering from fibrosis-associated pathologies.

Efficacy of liraglutide on glycemic endpoints in people of Western European and South Asian descent with T2DM using multiple daily insulin injections: results of the MAGNA VICTORIA studies

AIMS

Data on the effect of liraglutide on glycemic endpoints in people with T2DM using multiple daily insulin injections (MDI) are scarce, especially in the context of ethnicity.

METHODS

This is a secondary analysis of the placebo-controlled randomized clinical "MAGNA VICTORIA" trials in Western European (WE) and South Asian (SA) people with T2DM. Participants had inadequate glycemic control despite using metformin and/or sulfonylurea derivatives and/or insulin. Participants were assigned to liraglutide (1.8 mg) or placebo for 6 months, in addition to standard care. The primary endpoint number of participants reaching target HbA1c was compared for liraglutide versus placebo in the complete dataset and MDI-treated participants using Chi-square test. Liraglutide's efficacy in WE and SA was compared using a generalized linear model.

RESULTS

Forty-five subjects were randomized to liraglutide and 51 to placebo. In each group, one participant did not complete the study. Liraglutide-treated patients reached target HbA1c more frequently: 23/45 (51%) vs 11/51 (22%), relative probability 2.4 (1.3-4.3), p = 0.002. Subgroup analysis in 43 MDI participants showed that the proportion reaching target HbA1c using liraglutide was significantly higher than in placebo: 9/22 (41%) vs 1/21 (5%), p = 0.005. There was no difference between WE and SA in terms of liraglutide efficacy (p = 0.18).

CONCLUSIONS

Liraglutide treatment resulted in increased chance of reaching target HbA1c as compared to placebo. Liraglutide efficacy was sustained in participants using MDI regimens and those of SA descent. Liraglutide should be considered for T2DM people with inadequate glycemic control despite MDI.

Quantification of Myocardial Creatine and Triglyceride Content in the Human Heart: Precision and Accuracy of in vivo Proton Magnetic Resonance Spectroscopy

Background

Proton magnetic resonance spectroscopy (¹H‐MRS) of the human heart is deemed to be a quantitative method to investigate myocardial metabolite content, but thorough validations of in vivo measurements against invasive techniques are lacking.

Purpose

To determine measurement precision and accuracy for quantifications of myocardial total creatine and triglyceride content with localized ¹H‐MRS.

Study type

Test–retest repeatability and measurement validation study.

Subjects

Sixteen volunteers and 22 patients scheduled for open‐heart aortic valve replacement or septal myectomy.

Field Strength/Sequence

Prospectively ECG‐triggered respiratory‐gated free‐breathing single‐voxel point‐resolved spectroscopy (PRESS) sequence at 3 T.

Assessment

Myocardial total creatine and triglyceride content were quantified relative to the total water content by fitting the ¹H‐MR spectra. Precision was assessed with measurement repeatability. Accuracy was assessed by validating in vivo ¹H‐MRS measurements against biochemical assays in myocardial tissue from the same subjects.

Statistical Tests

Intrasession and intersession repeatability was assessed using Bland–Altman analyses. Agreement between ¹H‐MRS measurements and biochemical assay was tested with regression analyses.

Results

The intersession repeatability coefficient for myocardial total creatine content was 41.8% with a mean value of 0.083% ± 0.020% of the total water signal, and 36.7% for myocardial triglyceride content with a mean value of 0.35% ± 0.13% of the total water signal. Ex vivo myocardial total creatine concentrations in tissue samples correlated with the in vivo myocardial total creatine content measured with ¹H‐MRS: n = 22, r = 0.44; P < 0.05. Likewise, ex vivo myocardial triglyceride concentrations correlated with the in vivo myocardial triglyceride content: n = 20, r = 0.50; P < 0.05.

Data Conclusion

We validated the use of localized ¹H‐MRS of the human heart at 3 T for quantitative assessments of in vivo myocardial tissue metabolite content by estimating the measurement precision and accuracy.

Level of Evidence

2

Technical Efficacy Stage

2

Do Diabetes Mellitus Differences Exist within Generations? Three Generations of Moluccans in the Netherlands

Background: Diabetes mellitus (DM) is known to be more prevalent among migrants compared to their host populations. It is unclear whether DM prevalence differs between generations among migrants. We investigated the differences in DM prevalence among three generations of Moluccans, who have been living for over 65 years in the Netherlands, compared to the Dutch population. Methods: In this cross-sectional study, data of a healthcare insurance database on hospital and medication use (Achmea Health Database) were used. The dataset contained 5394 Moluccans and 52,880 Dutch persons of all ages. DM differences were assessed by means of logistic regression, adjusting for age, sex, urbanization, and area socio-economic status. Results: The prevalence of DM was higher in all generations of Moluccans compared to the Dutch. The adjusted odds ratios (AORs) for DM were significantly higher in total group of Moluccans compared to the Dutch (AOR 1.60, 95% CI 1.42–1.80) and across the first and second generation of Moluccans compared to the Dutch (first generation (1.73, 1.47–2.04) and second generation (1.44, 1.19–1.75). Higher AOR were found for first generation men (1.55, 1.22–1.97) and first (1.90, 1.52–2.37) and second (1.63, 1.24–2.13) generation Moluccan women compared to the Dutch. AOR for the third generation Moluccans was increased to a similar extent (1.51, 0.97–2.34), although not statistical significant. Conclusions: Our findings show higher odds of DM across generations of Moluccans compared to the Dutch. DM prevention strategies for minorities should be targeted at all migrant generations in host countries.

Effects of Liraglutide on Left Ventricular Function: A Meta-Analysis of Randomized, Placebo-Controlled Trials

BACKGROUND

The effects of liraglutide treatment on the left ventricular systolic and diastolic function remain unclear.

METHODS

This meta-analysis was conducted according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) statement. All relevant randomized, placebo-controlled trials (RCTs) were identified by searching PubMed, EMBASE, Cochrane Library, and ISI Web of Science from the establishment to January 2021 without language limitations. The weighted mean difference (WMD) with 95% confidence intervals (CIs) was calculated.

RESULTS

Ten placebo-controlled RCTs involving a total of 732 cases were included in the meta-analysis. Compared with the placebo group, liraglutide therapy showed no beneficial effect on the left ventricular ejection fraction (LVEF) at the end of the study (WMD: 2.120, 95% CI: -0.688 to 4.929, P=0.139) and ΔLVEF during the trial period (WMD: -0.651, 95% CI: -1.649 to 0.348, P=0.202). Similarly, no statistical differences were noted in diastolic function parameters between the two groups, including the value early diastolic filling velocity (E)/the mitral annular early diastolic velocity (e') (WMD: -0.763, 95% CI: -2.157 to 0.630, P=0.283), Δe' (WMD: -0.069, 95% CI: -0.481 to 0.343, P=0.742), and ΔE/e' (WMD: -0.683, 95% CI: -1.663 to 0.298, P=0.172).

CONCLUSIONS

Liraglutide treatment did not improve the left ventricular systolic and diastolic function. Given the study's limitations, further investigation may be warranted.

Diabetic cardiomyopathy: How can cardiac magnetic resonance help?

Diabetes cardiomyopathy is a specific form of cardiac disease characteristic for diabetic patients. Development of echocardiography enabled diagnosis of diabetic cardiomyopathy significantly before the occurrence of heart failure. Previously was believed that left ventricular (LV) diastolic dysfunction represents the first detectable stage of diabetic cardiomyopathy. However, speckle tracking imaging and strain evaluation showed that mechanical changes occur before LV diastolic dysfunction. Nevertheless, it seems that the first detectable stage of diabetic cardiomyopathy is myocardial interstitial fibrosis, which currently could be diagnosed predominantly by cardiac magnetic resonance. T1 mapping evaluation before and after contrast injection enables assessment of extracellular volume (ECV) and provides qualitative and quantitative assessment of interstitial myocardial fibrosis in diabetic patients. Studies showed a strong correlation between ECV-parameter of interstitial fibrosis and level of glycated hemoglobin-main parameter of glucose control in diabetes. This stage of fibrosis is still not LV hypertrophy and it is reversible, which is of a great importance because of timely initiation of treatment. The necessity for early diagnose is significantly increasing due to the fact that diabetes and arterial hypertension are concomitant disorders in the large number of diabetic patients and it has been known that the risk of interstitial myocardial fibrosis is multiplied in patients with both conditions. Future follow-up investigations are essential to determine the causal relationship between interstitial fibrosis and outcome in these patients. The aim of this review was to summarize the current knowledge and clinical usefulness of CMR in diabetic patients.

Mechanisms underlying diabetic cardiomyopathy: From pathophysiology to novel therapeutic targets

Diabetic cardiomyopathy (DC) is defined as a clinical condition of cardiac dysfunction that occurs in the absence of coronary atherosclerosis, valvular disease, and hypertension in patients with diabetes mellitus (DM). Despite the increasing worldwide prevalence of DC, due to the global epidemic of DM, the underlying pathophysiology of DC has not been fully elucidated. In addition, the clinical criteria for diagnosing DC have not been established, and specific therapeutic options are not currently available. The current paradigm suggests the impaired cardiomyocyte function arises due to a number of DM-related metabolic disturbances including hyperglycemia, hyperinsulinemia, and hyperlipidemia, which lead to diastolic dysfunction and signs and symptoms of heart failure. Other factors, which have been implicated in the progression of DC, include mitochondrial dysfunction, increased oxidative stress, impaired calcium handling, inflammation, and cardiomyocyte apoptosis. Herein, we review the current theories surrounding the occurrence and progression of DC, and discuss the recent advances in diagnostic methodologies and therapeutic strategies. Moreover, apart from conventional animal DC models, we highlight alternative disease models for studying DC such as the use of patient-derived human induced pluripotent stem cells (hiPSCs) for studying the mechanisms underlying DC. The ability to obtain hiPSC-derived cardiomyocytes from DM patients with a DC phenotype could help identify novel therapeutic targets for preventing and delaying the progression of DC, and for improving clinical outcomes in DM patients.