Infarct size, inflammatory burden and admission hyperglycemia in diabetic patients with acute myocardial infarction treated with SGLT2-inhibitors: a multicenter international registry

Background

Sodium-glucose co-transporter 2 inhibitors (SGLT2-I) currently receive intense clinical interest in patients with and without diabetes mellitus (DM) with pleiotropic beneficial effects. Nowadays, the inflammation response in the setting of acute myocardial infarction (AMI) has been proposed as a potential pharmacological intervention target. In this setting, we tested the hypothesis that the SGLT2-I displays anti-inflammatory effect along with glucose-lowering properties. We investigated the relationship between stress hyperglycemia, inflammation burden and infarct size in a cohort of type 2 diabetic AMI patients treated with SGLT2-I versus other oral anti-diabetic (OAD) agents alone.

Methods

In this multicenter international registry, all diabetic patients with AMI treated with percutaneous coronary intervention (PCI) between 2018 and 2021 were enrolled. Based on the admission anti-diabetic therapy, patients were divided into those receiving SGLT2-I versus other OAD agents alone. Patients on insulin therapy alone or combined with OAD agents were excluded from the study. The following inflammatory markers were evaluated at different time points: total white blood cell, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and neutrophil-to-platelet ratio (NPR), C-reactive protein. Infarct size was assessed by peak troponin levels and echocardiographic parameters.

Results

The final study population consisted of 583 patients hospitalized for AMI (both STEMI and NSTEMI) classified as SGLT2-I users (n=98) versus other OAD agents alone (n=485). Admission hyperglycemia was more prevalent among the other OAD agents group. Reduced infarct size was detected in patients treated with SGLT2-I compared to those treated with other OAD agents alone. Both at admission, and after 24 hours, inflammatory indices were significantly higher in patients treated with other OAD agents alone, with a significant increase in neutrophils levels at 24 hours, compared to the SGLT2-I group. In multivariate analysis, SGLT2-I emerged as a significant predictor of reduced inflammatory response (OR 0.45, 95% CI 0.27–0.75, p=0.002), together with peak troponin values, independently of age, admission creatinine values and admission glycemia.

Conclusions

Type 2 Diabetic patients hospitalized for AMI and receiving SGLT2-I exhibited modest inflammatory response and myocardial damage/infarct size compared to other OAD agents alone, independently of glucose-metabolic control. Our findings pave the way for new pathophysiological and therapeutic insights regarding the cardioprotective effect of SGLT2-I in the setting of coronary artery disease.

Funding Acknowledgement

Type of funding sources: None.

Opposite effects of β2-adrenoceptor gene deletion on insulin signaling in liver and skeletal muscle

BACKGROUND AND AIM

β₂-Adrenoceptors (β₂-ARs) are G protein-coupled receptors (GPCRs) expressed in the major insulin target tissues. The interplay between β₂-AR and insulin pathways is involved in the maintenance of glucose homeostasis. The aim of this study was to explore the consequences of β₂-ARs deletion on insulin sensitivity and insulin signaling cascade in metabolically active tissues.

METHODS AND RESULTS

We evaluated glucose homeostasis in skeletal muscle and liver of β₂-AR-null mice (β₂-AR^-/-) by performing in vivo (glucose tolerance test and insulin tolerance test) and ex vivo (glucose uptake and glycogen determination) experiments. β₂-AR gene deletion is associated with hepatic insulin resistance and preserved skeletal muscle insulin sensitivity. Importantly, we demonstrate that hepatic β₂-AR regulates insulin-induced AKT activation via Grb2-mediated SRC recruitment through a G_i-independent mechanism.

CONCLUSIONS

β-AR stimulation contributes to the development of early stages of insulin resistance progression in the liver. Our findings indicate that the cross-talk between β₂-AR and insulin signaling represents a fundamental target towards the development of novel therapeutic approaches to treat type 2 diabetes and metabolic syndrome.

Telemonitoring in heart failure patients treated by cardiac resynchronisation therapy with defibrillator (CRT-D): the TELECART Study

AIM

Telemonitoring (TM) is a safe and efficient monitoring system for internal cardioverter defibrillator device (ICD) recipients. TM has been used to track info on the clinical status of heart failure patients treated by ICD and/or cardiac resynchronisation therapy defibrillator (CRT-D). The aim of this study was to investigate the impact of TM on clinical outcomes in a population of CRT-D patients with heart failure.

METHODS

In a multicentre, randomised study, patients with chronic heart failure, New York Heart Association (NYHA) functional class II or III, left bundle branch block, severe left ventricle ejection fraction reduction (LVEF < 35%) have been identified and screened.

RESULTS

One hundred and ninety-one patients have been randomised to receive either a CRT-D with TM or a CRT-D with traditional ambulatory monitoring (control group) and completed the 12-month study follow-up. Primary endpoints were all cause death, cardiac death and hospital admission for heart failure. Secondary endpoints were atrial fibrillation, sustained episodes, non-sustained and self terminated ventricular tachyarrhythmia, sustained ventricular tachycardia, and ventricular fibrillation, ICD shocks and percentage of CRT-D responder patients. Univariate analysis identified the following factors predicting hospitalisation: TM, age, chronic kidney disease, hypercholesterolaemia, LVEF and NYHA class. At multivariate analysis, TM was the only factor predicting heart failure hospitalisation (hazard ratio 0.6, 0.42-0.79, 95% CI, p = 0.002), without affecting overall mortality and cardiac deaths events.

CONCLUSIONS

Taken together, our data indicate the importance of TM in predicting heart failure hospitalisation in patients treated with CRT-D.

Application of microRNAs in diagnosis and treatment of cardiovascular disease

Cardiovascular disease (CVD) is a major cause of morbidity and mortality worldwide. Innovative, more stringent diagnostic and prognostic biomarkers and effective treatment options are needed to lessen its burden. In recent years, microRNAs have emerged as master regulators of gene expression - they bind to complementary sequences within the mRNAs of their target genes and inhibit their expression by either mRNA degradation or translational repression. microRNAs have been implicated in all major cellular processes, including cell cycle, differentiation and metabolism. Their unique mode of action, fine-tuning gene expression rather than turning genes on/off, and their ability to simultaneously regulate multiple elements of relevant pathways makes them enticing potential biomarkers and therapeutic targets. Indeed, cardiovascular patients have specific patterns of circulating microRNA levels, often early in the disease process. This article provides a systematic overview of the role of microRNAs in the pathophysiology, diagnosis and treatment of CVD.

Cardiac resynchronisation therapy response predicts occurrence of atrial fibrillation in non-ischaemic dilated cardiomyopathy

AIM

The aim of this study was to determine whether or not cardiac resynchronization therapy (CRT) has a favourable effect on the incidence of new-onset atrial fibrillation (AF) in a homogeneous population of patients with non-ischaemic idiopathic-dilated cardiomyopathy and severe heart failure.

METHODS

We designed a single-centre prospective study and enrolled 58 patients AF naïve when received CRT. After 1 year of follow-up our population was subdivided into responders (72.4%) and non-responders (27.6%), so as to compare the incidence of AF after 1, 2 and 3 years of follow-up in these two groups.

RESULTS

Already after 1 year, there was a significant (p < 0.05) difference in new-onset AF in non-responder patients with respect to responders (18.2% vs. 3.3%). These data were confirmed at 2 years (33.3% vs. 12.2%) and 3 years (50.0% vs. 15.0%) follow-up. In particular, 3 years after device implantation non-responders had an increased risk to develop new-onset AF (OR = 5.67).

CONCLUSIONS

This is the first study analysing long-term effects of CRT in a homogeneous population of patients with non-ischaemic dilated cardiomyopathy, indicating the favourable role of this non-pharmacological therapy on the prevention of AF.

Overproduction of phosphoprotein enriched in diabetes (PED) induces mesangial expansion and upregulates protein kinase C-beta activity and TGF-beta1 expression

AIMS/HYPOTHESIS

Overproduction of phosphoprotein enriched in diabetes (PED, also known as phosphoprotein enriched in astrocytes-15 [PEA-15]) is a common feature of type 2 diabetes and impairs insulin action in cultured cells and in mice. Nevertheless, the potential role of PED in diabetic complications is still unknown.

METHODS

We studied the effect of PED overproduction and depletion on kidney function in animal and cellular models.

RESULTS

Transgenic mice overexpressing PED (PEDTg) featured age-dependent increases of plasma creatinine levels and urinary volume, accompanied by expansion of the mesangial area, compared with wild-type littermates. Serum and kidney levels of TGF-beta1 were also higher in 6- and 9-month-old PEDTg. Overexpression of PED in human kidney 2 cells significantly increased TGF-beta1 levels, SMAD family members (SMAD)2/3 phosphorylation and fibronectin production. Opposite results were obtained following genetic silencing of PED in human kidney 2 cells by antisense oligonucleotides. Inhibition of phospholipase D and protein kinase C-beta by 2-butanol and LY373196 respectively reduced TGF-beta1, SMAD2/3 phosphorylation and fibronectin production. Moreover, inhibition of TGF-beta1 receptor activity and SMAD2/3 production by SB431542 and antisense oligonucleotides respectively reduced fibronectin secretion by about 50%. TGF-beta1 circulating levels were significantly reduced in Ped knockout mice and positively correlated with PED content in peripheral blood leucocytes of type 2 diabetic patients.

CONCLUSIONS/INTERPRETATION

These data indicate that PED regulates fibronectin production via phospholipase D/protein kinase C-beta and TGF-beta1/SMAD pathways in kidney cells. Raised PED levels may therefore contribute to the abnormal accumulation of extracellular matrix and renal dysfunction in diabetes.

Endothelial alpha1-adrenoceptors regulate neo-angiogenesis

BACKGROUND AND PURPOSE

Intact endothelium plays a pivotal role in post-ischaemic angiogenesis. It is a phenomenon finely tuned by activation and inhibition of several endothelial receptors. The presence of alpha(1)-adrenoceptors on the endothelium suggests that these receptors may participate in regenerative phenomena by regulating the responses of endothelial cells involved in neo-angiogenesis.

EXPERIMENTAL APPROACH

We evaluated the expression of the subtypes of the alpha(1)-adrenoceptor in isolated endothelial cells harvested from Wistar-Kyoto (WKY) rats. We explored the possibility these alpha(1)-adrenoceptors may influence the pro-angiogenic phenotype of endothelial cells in vitro. In vivo, we used a model of hindlimb ischaemia in WKY rats, to assess the effects of alpha(1) adrenoceptor agonist or antagonist on angiogenesis in the ischaemic hindlimb by laser Doppler blood flow measurements, digital angiographies, hindlimb perfusion with dyed beads and histological evaluation.

KEY RESULTS

In vitro, pharmacological antagonism of alpha(1)-adrenoceptors in endothelial cells from WKY rats by doxazosin enhanced, while stimulation of these adrenoceptors with phenylephrine, inhibited endothelial cell proliferation and DNA synthesis, ERK and retinoblastoma protein (Rb) phosphorylation, cell migration and tubule formation. In vivo, we found increased alpha(1)-adrenoceptor density in the ischaemic hindlimb, compared to non-ischaemic hindlimb, suggesting an enhanced alpha(1)-adrenoceptor tone in the ischaemic tissue. Treatment with doxazosin (0.06 mg kg(-1) day(-1) for 14 days) did not alter systemic blood pressure but enhanced neo-angiogenesis in the ischaemic hindlimb, as measured by all our assays.

CONCLUSIONS

Our findings support the hypothesis that the alpha(1)-adrenoceptors in endothelial cells provide a negative regulation of angiogenesis.