Association between Markers of Fibrosis and Heart Failure Incidence in Patients with Type 2 Diabetes Mellitus

Role of Circulating Biomarkers in Diabetic Cardiomyopathy

Type 2 diabetes mellitus (T2DM) is a metabolic disorder that has alarmingly increased in incidence in recent decades. One of the most serious complications of T2DM is diabetic cardiomyopathy (DCM), an often underrecognized yet severe condition that is a leading cause of mortality among diabetic patients. In the early stages of DCM, patients typically show no symptoms and maintain normal systolic and diastolic left ventricle function, making early detection challenging. Currently available clinical markers are often not specific enough to detect the early stage of DCM. Conventional biomarkers of cardiac mechanical stress and injury, such as natriuretic peptides (NPs) and cardiac troponin I (cTnI), have shown limited predictive value for patients with T2DM. NPs have proven efficacy in detecting diastolic dysfunction in diabetic patients when used alongside 2D echocardiography, but their utility as biomarkers is limited to symptomatic individuals. While cTnI is a reliable indicator of general cardiac damage, it is not specific to cardiac injury caused by high glucose levels or T2DM. This underscores the need for research into biomarkers that can enable early diagnosis and management of DCM to reduce mortality rates. Promising novel biomarkers that showed good performance in detecting diastolic dysfunction or heart failure in diabetic patients include galectin-3, ST2, FGF-21, IGFBP-7, GDF-15, and TGF-β. This review summarizes the current understanding of DCM biomarkers, aiming to generate new ideas for the early recognition and treatment of DCM by exploring related pathophysiological mechanisms.

Update on clinical and experimental management of diabetic cardiomyopathy: addressing current and future therapy

Diabetic cardiomyopathy (DCM) is a severe secondary complication of type 2 diabetes mellitus (T2DM) that is diagnosed as a heart disease occurring in the absence of any previous cardiovascular pathology in diabetic patients. Although it is still lacking an exact definition as it combines aspects of both pathologies - T2DM and heart failure, more evidence comes forward that declares DCM as one complex disease that should be treated separately. It is the ambiguous pathological phenotype, symptoms or biomarkers that makes DCM hard to diagnose and screen for its early onset. This re-view provides an updated look on the novel advances in DCM diagnosis and treatment in the experimental and clinical settings. Management of patients with DCM proposes a challenge by itself and we aim to help navigate and advice clinicians with early screening and pharmacotherapy of DCM.

Epidemiology of heart failure in diabetes: a disease in disguise

Left ventricular diastolic dysfunction (LVDD) without symptoms, and heart failure (HF) with preserved ejection fraction (HFpEF) represent the most common phenotypes of HF in individuals with type 2 diabetes mellitus, and are more common than HF with reduced ejection fraction (HFrEF), HF with mildly reduced ejection fraction (HFmrEF) and left ventricular systolic dysfunction (LVSD) in these individuals. However, diagnostic criteria for HF have changed over the years, resulting in heterogeneity in the prevalence/incidence rates reported in different studies. We aimed to give an overview of the diagnosis and epidemiology of HF in type 2 diabetes, using both a narrative and systematic review approach; we focus narratively on diagnosing (using the 2021 European Society of Cardiology [ESC] guidelines) and screening for HF in type 2 diabetes. We performed an updated (2016-October 2022) systematic review and meta-analysis of studies reporting the prevalence and incidence of HF subtypes in adults ≥18 years with type 2 diabetes, using echocardiographic data. Embase and MEDLINE databases were searched and data were assessed using random-effects meta-analyses, with findings presented as forest plots. From the 5015 studies found, 209 were screened using the full-text article. In total, 57 studies were included, together with 29 studies that were identified in a prior meta-analysis; these studies reported on the prevalence of LVSD (n=25 studies, 24,460 individuals), LVDD (n=65 studies, 25,729 individuals), HFrEF (n=4 studies, 4090 individuals), HFmrEF (n=2 studies, 2442 individuals) and/or HFpEF (n=8 studies, 5292 individuals), and on HF incidence (n=7 studies, 17,935 individuals). Using Hoy et al's risk-of-bias tool, we found that the studies included generally had a high risk of bias. They showed a prevalence of 43% (95% CI 37%, 50%) for LVDD, 17% (95% CI 7%, 35%) for HFpEF, 6% (95% CI 3%, 10%) for LVSD, 7% (95% CI 3%, 15%) for HFrEF, and 12% (95% CI 7%, 22%) for HFmrEF. For LVDD, grade I was found to be most prevalent. Additionally, we reported a higher incidence rate of HFpEF (7% [95% CI 4%, 11%]) than HFrEF 4% [95% CI 3%, 7%]). The evidence is limited by the heterogeneity of the diagnostic criteria over the years. The systematic section of this review provides new insights on the prevalence/incidence of HF in type 2 diabetes, unveiling a large pre-clinical target group with LVDD/HFpEF in which disease progression could be halted by early recognition and treatment.Registration PROSPERO ID CRD42022368035.

Effects of empagliflozin on cardiac structure, function and biomarkers in patients with heart failure with preserved ejection fraction: study protocol for a randomised, placebo-controlled prospective trial

INTRODUCTION

Heart failure (HF) with preserved ejection fraction (HFpEF) has become the main type of HF worldwide. Although large randomised controlled studies have demonstrated the beneficial effects of sodium-glucose cotransporter 2 inhibitors among patients with HFpEF, the mechanisms remain unclear. Basic research suggests that empagliflozin inhibits myocardial fibrosis. Myocardial extracellular volume (ECV) can be calculated using cardiac MRI (CMRI), which can reflect the degree of diffuse myocardial fibrosis. Studies show that empagliflozin can reduce ECV and left ventricular mass (LVM) assessed by CMRI in patients with diabetes with coronary heart disease and patients without diabetes with HF with reduced ejection fraction. However, whether empagliflozin reduces ECV and LVM among patients with HFpEF is unclear. This study intends to use CMRI to evaluate ECV and LVM, combined with echocardiography and an assessment of related biomarkers, to determine whether empagliflozin can improve myocardial fibrosis and left ventricular remodelling in patients with HFpEF.

METHODS AND ANALYSIS

This report describes the study design of a prospective, multicentre, randomised, double-blind, placebo-controlled and parallel-group clinical study. A total of 180 participants with HFpEF aged 40-80 years old who meet the inclusion and exclusion criteria will be randomly divided into an empagliflozin treatment group or a placebo control group. The empagliflozin treatment group will receive 10 mg of empagliflozin per day for 6 months in addition to guideline-directed medical treatment, while the control group will receive placebo oral administration with guideline-directed medical therapy for 6 months. The primary outcomes are ECV and LVM changes measured by CMRI after 6 months of treatment.

ETHICS AND DISSEMINATION

The study design is approved by the ethical committee of Beijing Hospital (2022BJYYEC-070-02). The trial is registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn). The trial results will be published in peer-reviewed journals and conferences.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry (ChiCTR2200060862).

Potential clinical biomarkers and perspectives in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious cardiovascular complication and the leading cause of death in diabetic patients. Patients typically do not experience any symptoms and have normal systolic and diastolic cardiac functions in the early stages of DCM. Because the majority of cardiac tissue has already been destroyed by the time DCM is detected, research must be conducted on biomarkers for early DCM, early diagnosis of DCM patients, and early symptomatic management to minimize mortality rates among DCM patients. Most of the existing implemented clinical markers are not very specific for DCM, especially in the early stages of DCM. Recent studies have shown that a number of new novel markers, such as galactin-3 (Gal-3), adiponectin (APN), and irisin, have significant changes in the clinical course of the various stages of DCM, suggesting that we may have a positive effect on the identification of DCM. As a summary of the current state of knowledge regarding DCM biomarkers, this review aims to inspire new ideas for identifying clinical markers and related pathophysiologic mechanisms that could be used in the early diagnosis and treatment of DCM.