Recurrent cardiovascular events in patients with newly diagnosed acute coronary syndrome: Influence of diabetes and its management with medication

Effect of metformin on adverse outcomes in T2DM patients: Systemic review and meta-analysis of observational studies

Background

The cardiovascular protection effect of metformin on patients with type 2 diabetes mellitus (T2DM) remains inconclusive. This systemic review and meta-analysis were to estimate the effect of metformin on mortality and cardiovascular events among patients with T2DM.

Methods

A search of the Pubmed and EMBASE databases up to December 2021 was performed. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were pooled by a random-effects model with an inverse variance method.

Results

A total of 39 studies involving 2473009 T2DM patients were adopted. Compared to non-metformin therapy, the use of metformin was not significantly associated with a reduced risk of major adverse cardiovascular event (MACE) (HR = 1.06, 95%CI 0.91–1.22; I² = 82%), hospitalization (HR = 0.85, 95%CI 0.64–1.13; I² = 98%), heart failure (HR = 0.86, 95%CI 0.60–1.25; I² = 99%), stroke (HR = 1.16, 95%CI 0.88–1.53; I² = 84%), and risk of AMI (HR = 0.88, 95%CI 0.69–1.14; I² = 88%) in T2DM patients. Metformin was also not associated with significantly lowered risk of MACE compared to dipeptidyl peptidase-4 inhibitor (DPP-4i) in T2DM patients (HR = 0.95, 95%CI 0.73–1.23; I² = 84%).

Conclusions

The effect of metformin on some cardiovascular outcomes was not significantly better than the non-metformin therapy or DPP-4i in T2DM patients based on observational studies.

The Impact of Hypoglycemic Therapy on the Prognosis for Acute Coronary Syndrome in Patients with Type 2 Diabetes

The article discusses particular circumstances of acute coronary syndrome (ACS) in patients with type 2 diabetes (T2D). In addition, the available literature data and clinical guidelines reflecting the role of hypoglycemic therapy as a cardioprotection factor in ACS are analyzed. The article considers possible protective molecular mechanisms of various groups of drugs in ischemic cardiomyocytes.

Metformin: Expanding the Scope of Application-Starting Earlier than Yesterday, Canceling Later

Today the area of application of metformin is expanding, and a wealth of data point to its benefits in people without carbohydrate metabolism disorders. Already in the population of people leading an unhealthy lifestyle, before the formation of obesity and prediabetes metformin smooths out the adverse effects of a high-fat diet. Being prescribed at this stage, metformin will probably be able to, if not prevent, then significantly reduce the progression of all subsequent metabolic changes. To a large extent, this review will discuss the proofs of the evidence for this. Another recent important change is a removal of a number of restrictions on its use in patients with heart failure, acute coronary syndrome and chronic kidney disease. We will discuss the reasons for these changes and present a new perspective on the role of increasing lactate in metformin therapy.

Association of Metformin with the Mortality and Incidence of Cardiovascular Events in Patients with Pre-existing Cardiovascular Diseases

INTRODUCTION

Whether metformin reduces all-cause cardiovascular mortality and the incidence of cardiovascular events in patients with pre-existing cardiovascular diseases (CVD) remains inconclusive. Some randomised controlled trials (RCTs) and cohort studies have shown that metformin is associated with an increased risk of mortality and cardiovascular events.

METHODS

We conducted a pooling synthesis to assess the effects of metformin in all-cause cardiovascular mortality and incidence of cardiovascular events in patients with CVD. Studies published up to October 2021 in PubMed or Embase with a registration in PROSPERO (CRD42020189905) were collected. Both RCT and cohort studies were included. Hazard ratios (HR) with 95% CI were pooled across various trials using the random-effects model.

RESULTS

This study enrolled 35 published studies (in 14 publications) for qualitative synthesis and identified 33 studies (published in 26 publications) for quantitative analysis. We analysed a total of 61,704 patients, among them 58,271 patients were used to calculate all-cause mortality while 12,814 patients were used to calculate cardiovascular mortality. Compared with non-metformin control, metformin usage is associated with a reduction in all-cause mortality (HR: 0.90; 95% CI 0.83, 0.98; p = 0.01), cardiovascular mortality (HR: 0.89; 95% CI 0.85, 0.94; p < 0.0001), incidence of coronary revascularisation (HR: 0.79; 95% CI 0.64, 0.98; p = 0.03), and heart failure (HR: 0.90; 95% CI 0.87, 0.94; p < 0.0001) in patients with pre-existing cardiovascular diseases.

CONCLUSION

Metformin use is associated with a reduction in all-cause mortality, cardiovascular mortality, incidence of coronary revascularisation, and heart failure in patients with CVD; however, metformin usage was not associated with reduction in the incidence of myocardial infarction, angina, or stroke.

Clinical Characteristics, Achievement of Secondary Prevention Goals, and Outcomes of Patients with Recurrent Acute Coronary Syndrome

BACKGROUND

Because development of acute coronary syndrome (ACS) worsens the prognosis of patients with coronary artery disease, preventing recurrent ACS is crucial. However, the degree to which secondary prevention treatment goals are achieved in patients with recurrent ACS is unknown.

METHODS

214 consecutive ACS patients were classified as having First ACS (n=182) or Recurrent ACS (n=32), and the clinical characteristics of these groups were compared. Fifteen patients died or developed cardiovascular (CV) events during hospitalization, and the remaining 199 patients were followed from the date of hospital discharge to evaluate subsequent CV events.

RESULTS

Patients in the Recurrent ACS group were older than those in the First ACS group (76.8±10.8 years vs 68.8±13.4 years, p=0.002) and had a higher rate of diabetes mellitus (DM) (65.6% vs 36.8%, p=0.003). The rate of achieving a low-density lipoprotein cholesterol (LDL-C) level of <70 mg/dL in the Recurrent ACS group was only 28.1%, even though 68.8% of these patients were taking statins. An HbA1c level of <7.0% was achieved in 66.7% of patients with recurrent ACS who had been diagnosed with DM. Overall, 12.5% of patients with recurrent ACS had received optimal treatment for secondary prevention. CV events after hospital discharge were noted in 37.9% of the Recurrent ACS group and 21.2% of the First ACS group (log-rank test: p=0.004). However, recurrent ACS was not an independent risk factor for CV events (adjusted hazard ratio: 2.09, 95% confidence interval: 0.95 to 4.63, p=0.068).

CONCLUSION

Optimal treatment for secondary prevention was not achieved in some patients with recurrent ACS, and achievement of the guideline-recommended LDL-C goal for secondary prevention was especially low in this population.

Evaluation of the prognostic ability of serum uric acid for elderly acute coronary syndrome patients with diabetes mellitus: a prospective cohort study

OBJECTIVES

This study evaluated the prognostic power of serum uric acid (UA) in predicting adverse events in elderly acute coronary syndrome (ACS) patients with diabetes mellitus (DM).

METHODS

The analysis involved 718 ACS patients ‍>80 years old whose general clinical data and baseline blood biochemical indicators were collected prospectively from January 2006 to December 2012. These patients were classified into two groups based on DM status, and then followed up after discharge. The Kaplan-Meier method was used for major adverse cardiac event (MACE) rates and all-cause mortality. Multivariate Cox regression was performed to analyze the relationship between UA level and long-term clinical prognosis. Receiver operating characteristic (ROC) curves were analyzed to predict the cutoff value of UA in elderly ACS patients with DM. There were 242 and 476 patients in the DM and non-DM (NDM) groups, respectively, and the follow-up time after discharge was 40‒120 months (median, 63 months; interquartile range, 51‒74 months).

RESULTS

The all-cause mortality, cardiac mortality, and MACE rates in both DM and NDM patients were higher than those in the control group (P=0.001). All-cause mortalities, cardiac mortalities, and MACE rates in DM patients with moderate and high UA levels were significantly higher than those in the NDM group (P=0.001). Long-term survival rates decreased significantly with increased UA levels in the ACS groups (P=0.001). UA (odds ratio (OR)=2.106, 95% confidence interval (CI)=1.244‒3.568, P=0.006) was found to be an independent risk factor for all-cause mortality and MACE in elderly ACS patients with DM. The cutoff value of UA was 353.6 μmol/L (sensitivity, 67.4%; specificity, 65.7%).

CONCLUSIONS

Serum UA level is a strong independent predictor of long-term all-cause death and MACE in elderly ACS patients with DM.

Sodium-Glucose Cotransporter-2 Inhibitors at Discharge from Cardiology Hospitalization Department: Decoding A New Clinical Scenario

Sodium-glucose cotransporter-2 inhibitors (SGLT-2 inhibitors) are new glucose-lowering drugs (GLDs) with demonstrated cardiovascular benefits in patients with heart disease and type-2 diabetes mellitus (T2DM). However, their safety and efficacy when prescribed at hospital discharge are unexplored. This prospective, observational, longitudinal cohort study included 104 consecutive T2DM patients discharged from the cardiology department between April 2018 and February 2019. Patients were classified based on SGLT-2 inhibitor prescription and adjusted by propensity-score matching. The safety outcomes included discontinuation of GLDs; worsening renal function; and renal, hepatic, or metabolic hospitalization. The efficacy outcomes were death from any cause, cardiovascular death, cardiovascular readmission, and combined clinical outcome (cardiovascular death or readmission). The results showed that, the incidence rates of safety outcomes were similar in the SGLT-2 inhibitor or non-SGLT-2 inhibitor groups. Regarding efficacy, the SGLT-2 inhibitors group resulted in a lower rate of combined clinical outcomes (18% vs. 42%; hazard ratio (HR), 0.35; p = 0.02), any cause death (0% vs. 24%; HR, 0.79; p = 0.001) and cardiovascular death (0% vs. 17%; HR, 0.83; p = 0.005). No significant differences were found in cardiovascular readmissions. SGLT-2 inhibitor prescription at hospital discharge in patients with heart disease and T2DM was safe, well tolerated, and associated with a reduction in all-cause and cardiovascular deaths.

BK Channel Dysfunction in Diabetic Coronary Artery: Role of the E3 Ubiquitin Ligases

Diabetic coronary arterial disease is a leading cause of morbidity and mortality in diabetic patients. The impaired function of large-conductance calcium-activated potassium channels (BK channels) is involved in diabetic coronary arterial disease. Many studies have indicated that the reduced BK channel expression in diabetic coronary artery is attributed to ubiquitin-mediated protein degradation by the ubiquitin-proteasome system. This review focuses on the influence and the mechanisms of BK channel regulation by E3 ubiquitin ligases in diabetic coronary arterial disease. Thus, BK channels regulated by E3 ubiquitin ligase may play a pivotal role in the coronary pathogenesis of diabetic mellitus and, as such, is a potentially attractive target for therapeutic intervention.

Metformin protects against ischaemic myocardial injury by alleviating autophagy-ROS-NLRP3-mediated inflammatory response in macrophages

Myocardial ischaemia is usually accompanied by inflammatory response which plays a critical role in the myocardial healing and scar formation, while persistent inflammatory response contributes greatly to the myocardial remodeling and consequent heart failure. Metformin (Met), a widely used hypoglycemic drug, has increasingly been shown to exert remarkable cardioprotective effect on ischaemic myocardial injury such as acute myocardial infarction (AMI). However, the underlying mechanisms are still far from being fully understood. In this study, a mouse model of AMI was established through ligating the left anterior descending coronary artery (LAD), 100 mg/kg Met was given immediately after operation once daily for 3 days. It was demonstrated that Met effectively improved the cardiac haemodynamics (LVSP, LVEDP, +dp/dt, -dp/dt), diminished the infarct size, alleviated the disarrangement of myocardial cells and reduced the infiltration of inflammatory cells (macrophages, neutrophils and lymphocytes) in the heart of AMI mice. Mechanistically, Met decreased the expression of NLRP3 and enhanced the accumulation of LC3 puncta in F4/80-positive macrophages in the heart of AMI mice. Single cell suspension of cardiac macrophages was prepared from AMI mice and exhibited increased NLRP3 mRNA and protein expression. In contrast, Met decreased the expression of NLRP3 and p62, whereas increased the ratio of LC3II/LC3I. Additionally, both conditioned medium from H9c2 cardiomyocytes exposed to hydrogen peroxide (H9c2-H₂O₂-CM) and combination of mtDNA and ATP (mtDNA-ATP) increased the expression of NLRP3 and cleaved caspase-1 (p10) as well as intracellular ROS production in RAW264.7 macrophages, which were abrogated by Met treatment. Strikingly, chloroquine (CQ), 3-methyladenine (3-MA) and knockdown of autophagy-related gene (Atg5) abrogated the inhibitory effects of Met on H9c2-H₂O₂-CM and mtDNA-ATP-induced NLRP3 expression, release of IL-1β and IL-18 as well as ROS production in RAW264.7 macrophages. Collectively, these findings suggest that Met protects against ischaemic myocardial injury through alleviating autophagy-ROS-NLRP3 axis-mediated inflammatory response in macrophages.