Metformin and contrast-induced acute kidney injury in diabetic patients treated with primary percutaneous coronary intervention for ST segment elevation myocardial infarction: Amulticenter study

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.

Safety and Efficacy of Inpatient Diabetes Management with Non-insulin Agents: an Overview of International Practices

PURPOSE OF REVIEW

The field of inpatient diabetes has advanced significantly over the last 20 years, leading to the development of personalized treatment approaches. However, outdated guidelines still recommend the use of basal-bolus insulin therapy as the preferred treatment approach, and against the use of non-insulin anti-hyperglycemic agents.

RECENT FINDINGS

Several observational and prospective randomized controlled studies have demonstrated that oral anti-hyperglycemic agents are widely used in the hospital, including studies of DPP-4 agents and GLP-1 agonists. With advances in the field of inpatient diabetes management, a paradigm shift has occurred, from an approach of recommending "basal-bolus regimens" for all patients to a more precision medicine option for hospitalized non-critically ill patients with type 2 diabetes.

Continuous use of metformin in patients receiving contrast medium: what is the evidence? A systematic review and meta-analysis

OBJECTIVES

Substantial inconsistencies exist in current guidelines regarding recommendations of metformin usage with the administration of a contrast medium. We aimed to perform a meta-analysis to determine whether the risks of contrast-induced acute kidney injury (CI-AKI) and lactic acidosis increase with metformin use in diabetic patients receiving a contrast medium.

METHODS

Studies were retrieved from databases from inception to May 15, 2021. Studies that compared the outcomes of using metformin with not using metformin during contrast medium administration were included. The primary outcomes were incidence of CI-AKI and lactic acidosis. The secondary outcomes were renal function changes from baseline. Data analysis was using risk ratio (RR) for dichotomous outcomes and mean differences (MD) with 95% confidence intervals (CI) for continuous outcomes.

RESULTS

Analyses of two randomized controlled trials and four retrospective cohorts examining a total of 1459 patients revealed no significant differences in the incidence of CI-AKI (RR = 1.08; 95% CI, 0.72 to 1.63) and in changes in renal function measurements (serum creatinine: MD = 0.00 mg/dL, 95% CI, - 0.05 to 0.05; estimated glomerular filtration rate: MD = 0.22, 95% CI, - 2.47 to 2.91) after contrast medium administration between patients using and not using metformin.

CONCLUSIONS

There is no evidence that continuing metformin during contrast medium administration is associated with a higher risk of CI-AKI, lactic acidosis, or renal function deterioration compared to patients who discontinued metformin or who were not metformin users. The limited quality of the included studies may compromise the strength of evidence provided in this meta-analysis.

KEY POINTS

There is no need to discontinue metformin either before or after intravenous contrast medium exposure in patients with eGFR > 30 mL/min/1.73 m2. In patients receiving intra-arterial contrast medium with first-pass renal exposure, there is no need to withhold metformin if eGFR is above 60 mL/min/1.73 m2. For patients who have an eGFR level between 30 and 60 mL/min/1.73 m2 and are receiving intra-arterial contrast medium with first-pass renal exposure, no case of lactic acidosis was observed based on present data, but further evidence is needed to make a strong suggestion regarding its safety.

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.

Increasing metformin concentrations and its excretion in both rat and porcine ex vivo normothermic kidney perfusion model

INTRODUCTION

Metformin can accumulate and cause lactic acidosis in patients with renal insufficiency. Metformin is known to inhibit mitochondria, while renal secretion of the drug by proximal tubules indirectly requires energy. We investigated whether addition of metformin before or during ex vivo isolated normothermic machine perfusion (NMP) of porcine and rat kidneys affects its elimination.

RESEARCH DESIGN AND METHODS

First, Lewis rats were pretreated with metformin or saline the day before nephrectomy. Subsequently, NMP of the kidney was performed for 90 min. Metformin was added to the perfusion fluid in one of three different concentrations (none, 30 mg/L or 300 mg/L). Second, metformin was added in increasing doses to the perfusion fluid during 4 hours of NMP of porcine kidneys. Metformin concentration was determined in the perfusion fluid and urine by liquid chromatography-tandem mass spectrometry.

RESULTS

Metformin clearance was approximately 4-5 times higher than creatinine clearance in both models, underscoring secretion of the drug. Metformin clearance at the end of NMP in rat kidneys perfused with 30 mg/L was lower than in metformin pretreated rats without the addition of metformin during perfusion (both p≤0.05), but kidneys perfused with 300 mg/L trended toward lower metformin clearance (p=0.06). Creatinine clearance was not different between treatment groups. During NMP of porcine kidneys, metformin clearance peaked at 90 min of NMP (18.2±13.7 mL/min/100 g). Thereafter, metformin clearance declined, while creatinine clearance remained stable. This observation can be explained by saturation of metformin transporters with a Michaelis-Menten constant (95% CI) of 23.0 (10.0 to 52.3) mg/L.

CONCLUSIONS

Metformin was secreted during NMP of both rat and porcine kidneys. Excretion of metformin decreased under increasing concentrations of metformin, which might be explained by saturation of metformin transporters rather than a self-inhibitory effect. It remains unknown whether a self-inhibitory effect contributes to metformin accumulation in humans with longer exposure times.

Effect of continuous use of metformin on kidney function in diabetes patients with acute myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

Diabetes patients presenting with ST-segment elevation myocardial infarction (STEMI) scheduled for primary percutaneous coronary intervention (PCI) have an increased risk of contrast induced-acute kidney injury (CI-AKI). The effects of continuous use of metformin on kidney function are still controversial in patients submitted to primary PCI. This study aimed to assess continuous metformin therapy on kidney function in diabetic patients undergoing coronary intervention.

METHODS

Two hundred eighty-four patients with metformin-treated diabetes, who underwent coronary intervention within 24 h for STEMI, were enrolled in the retrospective study. All the patients had estimated glomerular filtration rate (eGFR) of > 30 mL/min/1.73 m2. According to the physicians' decisions after admission, 119 patients continued metformin treatment after primary PCI, while 165 patients discontinued it > 48 h after the procedure. Serum creatinine was collected at admission and within 48 h post primary PCI to evaluate the incidence of CI-AKI. We performed a multiple logistic regression analysis to examine the determinants of CI-AKI.

RESULTS

No statistical difference in CI-AKI incidence between the continuous and the discontinuous metformin group (12.6%vs10.3%, p = 0.545). Multivariable logistic regression analysis indicated eGFR ≤60 ml/min/1.73 m2[p = 0.025, OR: 3.131; 95% CI (1.156-8.482)] and contrast volume [p = 0.002, OR: 1.010; 95% CI (1.004-1.016)] were predictive factors of CI-AKI. Metformin therapy was irrelevant to CI-AKI [p = 0.365, OR: 0.698; 95% CI (0.320-1.521)]. No case of lactic acidosis was found in this study. Besides, the study supported discontinuation of metformin was not beneficial for patients' blood glucose control after admission.

CONCLUSIONS

The study indicated that the metformin continuation after primary PCI for STEMI in diabetic patients with eGFR > 30 ml/min / 1.73 m2 did not increase the risk of CI-AKI.

Practical guide to prevention of contrast-induced acute kidney injury after percutaneous coronary intervention

Contrast-induced acute kidney injury (CI-AKI) represents a common but serious complication of percutaneous coronary interventions (PCI)-and in general of all those examinations requiring iodinated contrast injection-which affects not only renal function but also long-term prognosis. While several prophylactic approaches were designed in order to prevent CI-AKI, most failed to demonstrate clear benefits in randomized trials, and their implementation is therefore discouraged in clinical practice. The most notorious examples include pre-procedural bicarbonate or N-acetylcysteine, and preprocedural withdrawal of ACE inhibitors/Angiotensin receptor blockers. Those strategies that were instead demonstrated effective include the appropriate use of preprocedural hydration, reduction in contrast volume utilization, adoption of techniques for zero- or ultra-low-contrast procedures, and pharmacological treatments with statins. In this brief review, we summarize the main preventive strategies into brief and pragmatic recommendations designed to improve everyday clinical practice.

Glucose-lowering therapy and cardiovascular outcomes in patients with type 2 diabetes mellitus and acute coronary syndrome

Diabetes is a common comorbidity in patients hospitalized for an acute coronary syndrome event, and prevalence is increasing. Among patients hospitalized with acute myocardial infarction, diabetes can be an independent predictor of mortality and new cardiovascular events; both short- and long-term outcomes are worse for patients with diabetes relative to those without, and undiagnosed diabetes is associated with greater mortality. The impact of glycemic control on cardiovascular outcomes and the best approach to treat hyperglycemia upon hospital admission for acute coronary syndrome in patients with or without known diabetes remain open questions. This review assesses available evidence for hyperglycemia management at the time of admission for acute coronary syndrome and, thereafter, finds that (1) admission plasma glucose plays a role in predicting adverse events, especially in patients with unknown diabetes; (2) glycated haemoglobin is a likely predictor of events in patients with unknown diabetes; and (3) hypoglycemia at the time of acute myocardial infarction hospital admission is an important predictor for mortality in patients with and without diabetes. Whether glucose-targeted insulin and glucose infusion have advantages over glucose-insulin-potassium infusion remains controversial. Evidence for the effect of novel glucose-lowering agents used at the time of an acute cardiovascular event is limited and requires more dedicated studies.

Effect of metformin on all-cause and cardiovascular mortality in patients with coronary artery diseases: a systematic review and an updated meta-analysis

BACKGROUND

Metformin is the most widely prescribed drug to lower glucose and has a definitive effect on the cardiovascular system. The goal of this systematic review and meta-analysis is to assess the effects of metformin on mortality and cardiac function among patients with coronary artery disease (CAD).

METHODS

Relevant studies reported before October 2018 was retrieved from databases including PubMed, EMBASE, Cochrane Library and Web of Science. Hazard ratio (HR) was calculated to evaluate the all-cause mortality, cardiovascular mortality and incidence of cardiovascular events (CV events), to figure out the level of left ventricular ejection fraction (LVEF), creatine kinase MB (CK-MB), type B natriuretic peptide (BNP) and to compare the average level of low density lipoprotein (LDL).

RESULTS

In this meta-analysis were included 40 studies comprising 1,066,408 patients. The cardiovascular mortality, all-cause mortality and incidence of CV events were lowered to adjusted HR (aHR) = 0.81, aHR = 0.67 and aHR = 0. 83 respectively after the patients with CAD were given metformin. Subgroup analysis showed that metformin reduced all-cause mortality in myocardial infarction (MI) (aHR = 0.79) and heart failure (HF) patients (aHR = 0.84), the incidence of CV events in HF (aHR = 0.83) and type II diabetes mellitus (T2DM) patients (aHR = 0.83), but had no significant effect on MI (aHR = 0.87) and non-T2DM patients (aHR = 0.92). Metformin is superior to sulphonylurea (aHR = 0.81) in effects on lowering the incidence of CV events and in effects on patients who don't use medication. The CK-MB level in the metformin group was lower than that in the control group standard mean difference (SMD) = - 0.11). There was no significant evidence that metformin altered LVEF (MD = 2.91), BNP (MD = - 0.02) and LDL (MD = - 0.08).

CONCLUSION

Metformin reduces cardiovascular mortality, all-cause mortality and CV events in CAD patients. For MI patients and CAD patients without T2DM, metformin has no significant effect of reducing the incidence of CV events. Metformin has a better effect of reducing the incidence of CV events than sulfonylureas.

Age modifies the risk factor profiles for acute kidney injury among recently diagnosed type 2 diabetic patients: a population-based study

The incidence of acute kidney injury (AKI) rises with age and is associated with multiple risk factors. Here, we compared the risk factors for AKI between younger and older incident diabetic patients to examine the trends in risk alteration for individual factors across different age groups. Between 2007 and 2013, we selected all incident type 2 diabetic adults from the Taiwan National Health Insurance registry, stratified based on age: young (< 65 years), old (≥ 65 but < 75 years), and older-old (≥ 75 years). All factors with potential renal influence (e.g., comorbidities, medications, and diagnostics/procedures) were recorded during the study period, with a nested case-controlled approach utilized to identify independent risk factors for AKI in each age group. Totally, 930,709 type 2 diabetic patients were categorized as young (68.7%), old (17.7%), or older-old (13.6%). Older-old patients showed a significantly higher incidence of AKI than the old and the young groups. Cardiovascular morbidities (hypertension, atrial fibrillation, acute coronary syndrome, and cerebrovascular disease) were shown to increase the risk of AKI, although the risk declined with increasing age. Chronic obstructive pulmonary disease and receiving cardiac catheterization elevated the risk of AKI preferentially in the older-old/old and older-old group, respectively, while the administration of angiotensin-converting enzyme/α-blocker and angiotensin receptor blocker/calcium channel blocker reduced the risk of AKI preferentially in the older-old and older-old/old group, respectively. In conclusion, our findings highlight the importance of devising age-specific risk factor panels for AKI in patients with recently diagnosed type 2 diabetes.

Impact of continuation of metformin prior to elective coronary angiography on acute contrast nephropathy in patients with normal or mildly impaired renal functions

Objective:

Discontinuation of metformin treatment in patients scheduled for elective coronary angiography (CAG) is controversial because of post-procedural risks including acute contrast-induced nephropathy (CIN) and lactic acidosis (LA). This study aims to discuss the safety of continuing metformin treatment in patients undergoing elective CAG with normal or mildly impaired renal functions.

Methods:

Our study was designed as a single-centered, randomized, and observational study including 268 patients undergoing elective CAG with an estimated glomerular filtration rate of >60 mL/min/1.73 m². Of these patients, 134 continued metformin treatment during angiography, whereas 134 discontinued it 24 h before the procedure. CIN was defined as either a 25% relative increase in serum creatinine levels from the baseline or a 0.5 mg/dL increase in the absolute value that measured 48 h after CAG. Logistic regression analysis was performed to identify independent predictors of CIN and LA after CAG.

Results:

Both groups were comparable in terms of demographics and laboratory values. CIN at 48 h was 8% (11/134) in the metformin continued group and 6% (8/134) in the metformin discontinued group (p=0.265). Patients in neither of the groups developed metformin-induced LA. Based on multiple regression analysis, the ejection fraction [p=0.029, OR: 0.760; 95% CI (0.590–0.970)] and contrast volume [p=0.016, OR: 0.022 95% CI (0.010–0.490)] were independent predictors of CIN.

Conclusion:

Patients scheduled for elective CAG with normal or mildly impaired renal functions and preserved left ventricular ejection fraction (>40%) may safely continue metformin treatment.

Platelet-to-lymphocyte ratio predicts contrast-induced acute kidney injury in diabetic patients with ST-elevation myocardial infarction

AIM

There has been a rise in contrast-induced acute kidney injury (CI-AKI). We examined the role of platelet-to-lymphocyte ratio (PLR) in predicting CI-AKI episodes in patients with myocardial infarction (MI) and diabetes.

METHODS

A total of 719 patients with diabetes and MI were enrolled. Study population was divided into: group 1 (n = 615) without CI-AKI and group 2 (n = 104) with CI-AKI.

RESULTS

Patients with CI-AKI had higher in-hospital mortality and a longer in-hospital stay. Median PLR was higher in patients with CI-AKI. Receiver operating characteristic analysis indicated PLR to be a good predictive tool in assessing the risk of CI-AKI. PLR was an independent predictor of CI-AKI (OR: 1.22; p < 0.0001).

CONCLUSION

These results suggest potential role for PLR as a biomarker of CI-AKI among diabetic patients with MI who undergo percutaneous coronary intervention.