Hyperglycemia and risk of ventricular tachycardia among patients hospitalized with acute myocardial infarction

Effect of dapagliflozin on malignant ventricular arrhythmias in elderly after acute myocardial infarction: a propensity score-matched cohort study

OBJECTIVE

This study aims to evaluate the effect of dapagliflozin (DAPA) on malignant ventricular arrhythmias (MVA) after acute myocardial infarction (AMI).

METHODS

A single-center, prospective and observational cohort study was conducted. We enrolled AMI patients from the ChangZhou Acute Myocardial Infarction Registry between January 2018 and November 2023. They were divided into two groups according to the use of dapagliflozin. The median follow-up time was 211 days. The primary endpoint of the study was the incidence of MVA during hospitalization, and the secondary endpoint was all-cause mortality rate during the follow-up period. Kaplan-Meier survival analysis and multifactorial logistic regression analysis were performed to assess the association between DAPA and the risk of MVA. Enrolled patients were matched on a 1:1 propensity score.

RESULTS

Of the 2607 AMI patients enrolled, MVA were reported postoperatively in 123 (4.7%)patients. Cardiovascular death occurred in 93 (3.6%) patients. The average age of the enrolled patients was 65.03 ± 0.27 years. Of participants assigned to dapagliflozin, 8 out of 363 patients (2.2%) experienced MVA compared with 115 out of 2244 patients (5.1%) in the control group (odds ratio, OR = 0.392; 95% confidence interval, 95% CI: 0.171-0.900; P = 0.027). After 1:1 propensity score matching, DAPA remained able to reduce the risk of MVA in patients with AMI. (OR = 0.340; 95% CI: 0.121-0.960; P = 0.042). At a median follow-up of 211 days, all-cause mortality remained lower in the DAPA group than in the control group after matching (P = 0.033).

CONCLUSION

Dapagliflozin may attenuate the risk of MVA and all-cause mortality in elderly AMI patients, highlighting its potential as a therapeutic adjunct. However, these findings require validation in large-scale randomized trials.

The triglyceride-glucose index, ventricular arrhythmias and major cardiovascular events in patients at high risk of sudden cardiac death

BACKGROUND

The association between the triglyceride-glucose (TyG) index and ventricular arrhythmias (VAs) is unclear. This study aimed to investigate the relationship between the TyG index, VAs, and major cardiovascular events in patients at high risk of sudden cardiac death (SCD).

METHODS

We enrolled 1046 patients at high risk of SCD with an indication for implantable cardioverter-defibrillator (ICD) implantation at the Chinese National Center for Cardiovascular Diseases. The primary outcome was VAs, defined as sustained ventricular tachycardia and ventricular fibrillation documented by the ICD. The secondary outcomes were cardiac mortality, heart transplantation, and rehospitalization for heart failure.

RESULTS

The mean (± SD) age was 59.6 ± 14.0 years old, and 25.7% were female. During the mean follow-up of 36.1 months, 342 (32.7%) patients had VAs, and 185 (17.7%) patients had major cardiovascular events. The mean fasting glucose and triglyceride levels were 111.9 ± 42.7 mg/dL and 140.0 ± 95.4 mg/L, respectively, with a TyG index range of 6.96-11.8. In the Fine-Gray subdistribution hazard model analysis, an increase in the TyG index was associated with a significant increase in the VAs (per 1 TyG index, hazard ratio [HR] 2.95; 95% confidence interval [CI], 2.29-3.80) and secondary outcome (HR 2.84; 95% CI 1.86-4.34). When stratified into tertiles, the risk of VAs was significantly higher in the highest tertile (HR 4.08; 95% CI, 2.81-5.92) than in the lowest tertile. Analysis of the secondary outcome revealed similar findings (HR 3.18; 95% CI, 1.73-5.85).

CONCLUSIONS

In our cohort, the pre-operational TyG index is significantly associated with VAs and major cardiovascular events for patients with high risk of SCD.

Ventricular Tachycardia and Hospital Readmission in Patients Discharged From the Hospital After an Acute Myocardial Infarction

Background

Although ventricular tachycardia (VT) occurring during hospitalization for an acute myocardial infarction (AMI) increases mortality risk, its relationship with 30-day postdischarge rehospitalization has not been examined.

Methods

Using data from the Worcester Heart Attack Study, we examined the association between early (during the first 48 hours of admission) and late (after 48 hours from admission) VT with 30-day postdischarge all-cause and cardiovascular disease (CVD)-related rehospitalization while analytically controlling for several demographic and clinical factors.

Results

The study population consisted of 3534 patients who were hospitalized with an AMI between 2005 and 2015 (average age, 67.2 years; 40.7% women); VT occurred in 452 patients (13.7%), with the majority of instances (81.2%) occurring within 48 hours of admission. The 30-day all-cause rehospitalization rate was 17.3%, with 70.9% of the hospitalizations related to CVD. The odds of rehospitalization were 1.63 times (95% confidence interval [CI] = 0.99-2.69) and 1.12 times (95% CI = 0.83-1.51) higher for patients with AMI who developed late VT and early VT, respectively, compared to patients who did not develop VT. The risk of rehospitalization among patients with late VT was higher (odds ratio = 2.22 (95% CI = 0.79-6.26) in those with ST-segment-elevation AMI, compared to those with non-ST-segment-elevation AMI (odds ratio = 1.45 (95% CI = 0.81-2.57); early VT was not associated with rehospitalization in patients with either AMI subtype. No significant association was present between the occurrence of VT and CVD-related rehospitalization.

Conclusions

Patients who develop late VT may experience a higher risk of 30-day rehospitalization following hospital discharge for AMI, especially among those with ST-segment-elevation AMI. Larger studies are needed to confirm our findings.

Prognostic implications of stress hyperglycemia ratio in patients with myocardial infarction with nonobstructive coronary arteries

BACKGROUND

The role of stress hyperglycemia in acute myocardial infarction (AMI) has long been emphasized. Recently, the stress hyperglycemia ratio (SHR), a novel index reflecting an acute glycemia rise, has shown a good predictive value in AMI. However, its prognostic power in myocardial infarction with nonobstructive coronary arteries (MINOCA) remains unclear.

METHODS

In a prospective cohort of 1179 patients with MINOCA, relationships between SHR levels and outcomes were analyzed. SHR was defined as acute-to-chronic glycemic ratio using admission blood glucose (ABG) and glycated hemoglobin. The primary endpoint was defined as major adverse cardiovascular events (MACE), including all-cause death, nonfatal MI, stroke, revascularization, and hospitalization for unstable angina or heart failure. Survival analyses and receiver-operating characteristic (ROC) curve analyses were performed.

RESULTS

Over the median follow-up of 3.5 years, the incidence of MACE markedly increased with higher SHR tertile levels (8.1%, 14.0%, 20.5%; p < 0.001). At multivariable Cox analysis, elevated SHR was independently associated with an increased risk of MACE (HR 2.30, 95% CI: 1.21-4.38, p = 0.011). Patients with rising tertiles of SHR also had a significantly higher risk of MACE (tertile 1 as reference; tertile 2: HR 1.77, 95% CI: 1.14-2.73, p = 0.010; tertile 3: HR 2.64, 95% CI: 1.75-3.98, p < 0.001). SHR remained a robust predictor of MACE in patients with and without diabetes; whereas ABG was no longer associated with the MACE risk in diabetic patients. SHR showed an area under the curve of 0.63 for MACE prediction. By incorporating SHR to TIMI risk score, the combined model further improved the discrimination for MACE.

CONCLUSIONS

The SHR independently confers the cardiovascular risk after MINOCA, and may serve as a better predictor than glycemia at admission alone, particularly in those with diabetes.KEY MESSAGESStress hyperglycemia ratio (SHR) is independently associated with the prognosis in a distinct population with myocardial infarction with nonobstructive coronary arteries (MINOCA).SHR is a better predictor of prognosis than admission glycemia alone, especially in diabetic patients with MINOCA.SHR may serve as a prognostic marker for risk stratification as well as a potential target for tailored glucose-lowering treatment in MINOCA.

Ventricular tachycardia and in-hospital mortality in the intensive care unit

Background

Continuous electrocardiographic (ECG) monitoring is used to identify ventricular tachycardia (VT), but false alarms occur frequently.

Objective

The purpose of this study was to assess the rate of 30-day in-hospital mortality associated with VT alerts generated from bedside ECG monitors to those from a new algorithm among intensive care unit (ICU) patients.

Methods

We conducted a retrospective cohort study in consecutive adult ICU patients at an urban academic medical center and compared current bedside monitor VT alerts, VT alerts from a new-unannotated algorithm, and true-annotated VT. We used survival analysis to explore the association between VT alerts and mortality.

Results

We included 5679 ICU admissions (mean age 58 ± 17 years; 48% women), 503 (8.9%) experienced 30-day in-hospital mortality. A total of 30.1% had at least 1 current bedside monitor VT alert, 14.3% had a new-unannotated algorithm VT alert, and 11.6% had true-annotated VT. Bedside monitor VT alert was not associated with increased rate of 30-day mortality (adjusted hazard ratio [aHR] 1.06; 95% confidence interval [CI] 0.88-1.27), but there was an association for VT alerts from our new-unannotated algorithm (aHR 1.38; 95% CI 1.12-1.69) and true-annotated VT(aHR 1.39; 95% CI 1.12-1.73).

Conclusion

Unannotated and annotated-true VT were associated with increased rate of 30-day in-hospital mortality, whereas current bedside monitor VT was not. Our new algorithm may accurately identify high-risk VT; however, prospective validation is needed.

The predictive value of machine learning for mortality risk in patients with acute coronary syndromes: a systematic review and meta-analysis

BACKGROUND

Acute coronary syndromes (ACS) are the leading cause of global death. Optimizing mortality risk prediction and early identification of high-risk patients is essential for developing targeted prevention strategies. Many researchers have built machine learning (ML) models to predict the mortality risk in ACS patients. Our meta-analysis aimed to evaluate the predictive value of various ML models in predicting death in ACS patients at different times.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library were searched systematically from database establishment to March 12, 2022 for studies developing or validating at least one ML predictive model for death in ACS patients. We used PROBAST to assess the risk of bias in the reported predictive models and a random-effects model to assess the pooled C-index and accuracy of these models.

RESULTS

Fifty papers were included, involving 216 ML prediction models, 119 of which were externally validated. The combined C-index of the ML models in the validation cohort predicting the in-hospital mortality, 30-day mortality, 3- or 6-month mortality, and 1 year or above mortality in ACS patients were 0.8633 (95% CI 0.8467-0.8802), 0.8296 (95% CI 0.8134-0.8462), 0.8205 (95% CI 0.7881-0.8541), and 0.8197 (95% CI 0.8042-0.8354), respectively, with the corresponding combined accuracy of 0.8569 (95% CI 0.8411-0.8715), 0.8282 (95% CI 0.7922-0.8591), 0.7303 (95% CI 0.7184-0.7418), and 0.7837 (95% CI 0.7455-0.8175), indicating that the ML models were relatively excellent in predicting ACS mortality at different times. Furthermore, common predictors of death in ML models included age, sex, systolic blood pressure, serum creatinine, Killip class, heart rate, diastolic blood pressure, blood glucose, and hemoglobin.

CONCLUSIONS

The ML models had excellent predictive power for mortality in ACS, and the methodologies may need to be addressed before they can be used in clinical practice.

Association between admission-blood-glucose-to-albumin ratio and clinical outcomes in patients with ST-elevation myocardial infarction undergoing percutaneous coronary intervention

Introduction

It is unclear whether admission-blood-glucose-to-albumin ratio (AAR) predicts adverse clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) who are treated with percutaneous coronary intervention (PCI). Here, we performed a observational study to explore the predictive value of AAR on clinical outcomes.

Methods

Patients diagnosed with STEMI who underwent PCI between January 2010 and February 2020 were enrolled in the study. The patients were classified into three groups according to AAR tertile. The primary outcome was in-hospital all-cause mortality, and the secondary outcomes were in-hospital major adverse cardiac events (MACEs), as well as all-cause mortality and MACEs during follow-up. Logistic regression, Kaplan-Meier analysis, and Cox proportional hazard regression were the primary analyses used to estimate outcomes.

Results

Among the 3,224 enrolled patients, there were 130 cases of in-hospital all-cause mortality (3.9%) and 181 patients (5.4%) experienced MACEs. After adjustment for covariates, multivariate analysis demonstrated that an increase in AAR was associated with an increased risk of in-hospital all-cause mortality [adjusted odds ratio (OR): 2.72, 95% CI: 1.47-5.03, P = 0.001] and MACEs (adjusted OR: 1.91, 95% CI: 1.18-3.10, P = 0.009), as well as long-term all-cause mortality [adjusted hazard ratio (HR): 1.64, 95% CI: 1.19-2.28, P = 0.003] and MACEs (adjusted HR: 1.58, 95% CI: 1.16-2.14, P = 0.003). Receiver operating characteristic (ROC) curve analysis indicated that AAR was an accurate predictor of in-hospital all-cause mortality (AUC = 0.718, 95% CI: 0.675-0.761) and MACEs (AUC = 0.672, 95% CI: 0.631-0.712).

Discussion

AAR is a novel and convenient independent predictor of all-cause mortality and MACEs, both in-hospital and long-term, for STEMI patients receiving PCI.

Acute hyperglycemia, a rabble-rouser or innocent bystander? A prospective analysis of clinical implications of acute hyperglycemia in STE-ACS patients

BACKGROUND

Acute hyperglycemia is considered an independent prognosticator of both in-hospital and long-term outcomes in patients with acute coronary syndrome (ACS). This study aimed To analyze the incidence of acute hyperglycemia and its impact on the adverse in-hospital outcome in patients with STE-ACS undergoing primary percutaneous coronary intervention (PCI).

METHODS

In this study, we enrolled patients presenting with STE-ACS and undergoing primary PCI at a tertiary care cardiac center. Acute hyperglycemia was defined as random plasma glucose (RBS) > 200 mg/dl at the time of presentation to the emergency room.

RESULTS

Of the 4470 patients, 78.8% were males, and the mean age was 55.52 ± 11 years. In total, 39.4% (1759) were found to have acute hyperglycemia, and of these, 59% (1037) were already diagnosed with diabetes. Patients with acute hyperglycemia were observed to have a higher incidence of heart failure (8.2% vs. 5.5%; p < 0.001), contrast-induced nephropathy (10.9% vs. 7.4%; p < 0.001), and in-hospital mortality (5.7% vs. 2.5%; p < 0.001). On multivariable analysis, acute hyperglycemia was found to be an independent predictor of mortality with an adjusted odds ratio of 1.81 [1.28-2.55]. Multi-vessel disease (1.73 [1.17-2.56]), pre-procedure left ventricular end-diastolic pressure (LVEDP) (1.02 [1.0-1.03]), and Killip class III/IV (4.55 [3.09-6.71]) were found to be the additional independent predictors of in-hospital mortality.

CONCLUSIONS

Acute hyperglycemia, regardless of diabetic status, is an independent predictor of in-hospital mortality among patients with STE-ACS undergoing primary PCI. Acute hyperglycemia, along with other significant predictors such as multi-vessel involvement, LVEDP, and Killip class III/IV, can be considered for the risk stratification of these patients.

Dysglycemia and arrhythmias

Disorders in glucose metabolism can be divided into three separate but interrelated domains, namely hyperglycemia, hypoglycemia, and glycemic variability. Intensive glycemic control in patients with diabetes might increase the risk of hypoglycemic incidents and glucose fluctuations. These three dysglycemic states occur not only amongst patients with diabetes, but are frequently present in other clinical settings, such as during critically ill. A growing body of evidence has focused on the relationships between these dysglycemic domains with cardiac arrhythmias, including supraventricular arrhythmias (primarily atrial fibrillation), ventricular arrhythmias (malignant ventricular arrhythmias and QT interval prolongation), and bradyarrhythmias (bradycardia and heart block). Different mechanisms by which these dysglycemic states might provoke cardiac arr-hythmias have been identified in experimental studies. A customized glycemic control strategy to minimize the risk of hyperglycemia, hypoglycemia and glucose variability is of the utmost importance in order to mitigate the risk of cardiac arrhythmias.

Glycemic variability and in-hospital death of critically ill patients and the role of ventricular arrhythmias

BACKGROUND

Abnormal glycemic variability is common in the intensive care unit (ICU) and is associated with increased in-hospital mortality and major adverse cardiovascular events, but little is known about whether adverse outcomes are partly mediated by ventricular arrhythmias (VA). We aimed to explore the association between glycemic variability and VA in the ICU and whether VA related to glycemic variability mediate the increased risk of in-hospital death.

METHODS

We extracted all measurements of blood glucose during the ICU stay from The Medical Information Mart for Intensive Care IV (MIMIC-IV) database version 2.0. Glycemic variability was expressed by the coefficient of variation (CV), which was calculated by the ratio of standard deviation (SD) and average blood glucose values. The outcomes included the incidence of VA and in-hospital death. The KHB (Karlson, KB & Holm, A) is a method to analyze the mediation effect for nonlinear models, which was used to decompose the total effect of glycemic variability on in-hospital death into a direct and VA-mediated indirect effect.

RESULTS

Finally, 17,756 ICU patients with a median age of 64 years were enrolled; 47.2% of them were male, 64.0% were white, and 17.8% were admitted to the cardiac ICU. The total incidence of VA and in-hospital death were 10.6% and 12.8%, respectively. In the adjusted logistic model, each unit increase in log-transformed CV was associated with a 21% increased risk of VA (OR 1.21, 95% CI: 1.11-1.31) and a 30% increased risk (OR 1.30, 95% CI: 1.20-1.41) of in-hospital death. A total of 3.85% of the effect of glycemic variability on in-hospital death was related to the increased risk of VA.

CONCLUSION

High glycemic variability was an independent risk factor for in-hospital death in ICU patients, and the effect was caused in part by an increased risk of VA.

Occurrence of Severe Arrhythmias in Patients with Non-ST Elevation Acute Coronary Syndrome (NSTE-ACS): A Retrospective Study

BACKGROUND

Non-ST elevation acute coronary syndrome (NSTE-ACS) is one of the most frequent manifestations of coronary artery disease. The occurrence of serious heart rhythm disorders (SHRDs) in NSTE-ACS is not well documented. However, continuous heart rhythm monitoring is recommended during the initial management of NSTE-ACS. The targeted monitoring of patients at greater risk for SHRDs could facilitate patients' care in emergency departments (EDs) where the flow of patients is continuously increasing.

METHODS

This retrospective single-center study included 480 patients from emergency and cardiology departments within the Strasbourg University Hospital between 1 January 2019 and 31 December 2020. The objective was to estimate the frequency of the occurrence of SHRDs among patients with NSTE-ACS. The secondary objective was to highlight the factors associated with a higher risk of SHRDs.

RESULTS

The proportion of SHRDs during the first 48 h of hospital care was 2.3% (CI95%: 1.2-4.1%, n = 11). Two time periods were considered: before coronary angiography (1.0%), and during, or after coronary angiography (1.3%). In the first group, two patients required immediate treatment (0.4% of the patients) and no death occurred. In the univariate analysis, the variables significantly associated with SHRDs were age, anticoagulant medication, a decrease in glomerular filtration rate, plasmatic hemoglobin, and left ventricle ejection fraction (LVEF), and an increase in plasmatic troponin, BNP, and CRP levels. In the multivariable analysis, plasmatic hemoglobin > 12 g/dL seemed to be a protective factor for SHRDs.

CONCLUSIONS

In this study, SHRDs were rare and, most often, spontaneously resolved. These data challenge the relevance of systematic rhythm monitoring during the initial management of patients with NSTE-ACS.

Association of hyperglycemia ratio and ventricular arrhythmia in critically ill patients admitted to the intensive care unit

INTRODUCTION

The relationship between relative hyperglycemia and ventricular arrhythmia (VA) in critically ill patients admitted to intensive care units (ICU) remains unclear. This study aims to investigate the association between stress hyperglycemia ratio (SHR) and VA in this population.

METHODS

This retrospective and observational study analyzed data from 4324 critically ill patients admitted to the ICU, obtained from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The SHR was calculated as the highest blood glucose level during the first 24 h of ICU admission divided by the admission blood glucose level. Based on the optimal cut-off values under the receiver operating characteristic curve, patients were stratified into high SHR (≥ 1.31) and low SHR (< 1.31) group. To investigate the impact of diabetes mellitus (DM) on the outcome, patients were stratified as low SHR/DM; low SHR/non-DM; high SHR/DM, and high SHR/non-DM. Restricted cubic spline (RCS) and logistic regression analysis were performed to analyze the relationship between SHR and VA.

RESULTS

A total of 4,324 critically ill patients were included in this retrospective and observational study. The incidence of VA was higher in the high SHR group. Multiple-adjusted RCS revealed a "J-shaped" correlation between SHR and VA morbidity. The logistic regression model demonstrated that high SHR was associated with VA. The high SHR/non-DM group had a higher risk of VA than other groups stratified based on SHR and DM. Subgroup analysis showed that high SHR was associated with an increased risk of VA in patients with coronary artery disease.

CONCLUSION

High SHR is an independent risk factor and has potential as a biomarker of higher VT/VF risk in ICU-admitted patients.

The association of glucose control on in-hospital mortality in the cardiac intensive care unit

BACKGROUND

Current guidelines recommend maintaining serum blood glucose (BG) levels between 150 and 180 mg/dL for patients admitted to the intensive care unit (ICU); however, these recommendations are based on randomized controlled trials among general ICU patients and observational studies among specific subgroups. Little is known about the impact of glucose control among patients cared for in the cardiac intensive care unit (CICU).

METHODS

This was a retrospective cohort analysis of patients >18 years of age admitted to the University of Michigan CICU from December 2016 through December 2020 with at least one BG measurement during CICU admission. The primary outcome was in-hospital mortality. The secondary outcome was CICU length of stay.

RESULTS

A total of 3217 patients were included. When analyzed based on quartiles of mean CICU BG, there were significant differences in in-hospital mortality across BG quartiles for those with diabetes mellitus (DM) and those without DM. In multivariable logistic regression, age, Elixhauser comorbidity score, use of mechanical ventilation, any hypoglycemic event, and any BG value >180 mg/dL were significant predictors for in-hospital mortality in both patients with and without DM, yet average BG was only predictive of in-hospital mortality in patients without DM.

CONCLUSIONS

This study highlights the importance of glucose control in critically ill adult patients admitted to the CICU. The trends in mortality based on quartiles and deciles of average BG suggest a difference in optimal blood glucose levels in those with and without DM. However, regardless of diabetes status, mortality increases with higher average BG.

Admission Blood Glucose Level as a Predictor of Outcome in Intensive Care Patients: A Cross-Sectional Study

INTRODUCTION

In the Intensive care unit (ICU), hyperglycemia is often observed; commonly associated with pre-existing diabetes or pre-diabetes or in nondiabetic patients. This study aimed to assess the role of admission blood sugar levels with outcomes in ICU patients.

METHODS

A total of 100 patients above 18 years of age were included in the study. A detailed history regarding the patient's age, sex, and any chronic illness were taken. Heart rate, systolic blood pressure, and Glasgow coma scale (GCS) scores were recorded. Admission blood glucose level, blood urea, total leucocyte count, and serum electrolytes were measured; and the outcome was noted.

RESULTS

The number of diabetics was significantly higher (65.5%) in the random blood sugar (RBS) ≥180 group. Hyponatremia was significantly associated with hyperglycemia. Patients with hyperglycemia had serum bicarbonate <18. A significantly greater number of patients with hyperglycemia had GCS scores of <8, and required mechanical ventilation. The duration of ICU stay and non-survivors were significantly higher in the hyperglycemia group. Random blood sugar at admission as a factor to assess outcome showed a sensitivity of 68.4 and specificity of 59.3 with a cut-off value of 197.

CONCLUSION

Admission of random blood sugar was significantly associated with poor outcomes. More stringent surveillance as well as routine blood glucose checks at the time of hospital admission should be emphasized.

Prognostic impact of stress hyperglycemia ratio in acute myocardial infarction patients with and without diabetes mellitus

BACKGROUND AND AIMS

Stress hyperglycemia ratio (SHR) is associated with increased in-hospital morbidity and mortality in patients with acute myocardial infarction (AMI). We aimed to investigate the impact of stress "hyperglycemia" on long-term mortality after AMI in patients with and without diabetes mellitus (DM).

METHODS AND RESULTS

We included 2089 patients with AMI between February 2014 and March 2018. SHR was measured with the fasting glucose divided by the estimated average glucose derived from glycosylated hemoglobin (HbA1c). The primary endpoint was all-cause death. Of 2 089 patients (mean age: 65.7 ± 12.4, 76.7% were men) analyzed, 796 (38.1%) had DM. Over a median follow-up of 2.7 years, 141 (6.7%) and 150 (7.2%) all-cause deaths occurred in the diabetic and nondiabetic cohorts, respectively. Compared with participants with low SHR (<1.24 in DM; <1.14 in non-DM), the hazard ratios and 95% confidence intervals for those with high SHR (≥1.24 in DM; ≥1.14 in non-DM) for all-cause mortality were 2.23 (1.54-3.23) and 1.79 (1.15-2.78); for cardiovascular mortality were 2.42 (1.63-3.59) and 2.10 (1.32-3.35) in DM and non-DM subjects, respectively. The mortality prediction was improved in the diabetic individuals with the incorporation of SHR into the Global Registry of Acute Coronary Events (GRACE) score, showing an increase in a continuous net reclassification index of 0.184 (95%CI: 0.003-0.365) and an absolute integrated discrimination improvement of 0.014 (95%CI: 0.002-0.025).

CONCLUSION

The improvement in the prediction of long-term mortality beyond the GRACE score indicates the potential of SHR as a biomarker for post-MI risk stratification among patients with DM.

REGISTRATION NUMBER FOR CLINICAL TRIALS

NCT03533543.

In-hospital arrhythmic burden reduction in diabetic patients with acute myocardial infarction treated with SGLT2-inhibitors: Insights from the SGLT2-I AMI PROTECT study

Background

Sodium-glucose co-transporter 2 inhibitors (SGLT2-i) have shown significant cardiovascular benefits in patients with and without type 2 diabetes mellitus (T2DM). They have also gained interest for their potential anti-arrhythmic role and their ability to reduce the occurrence of atrial fibrillation (AF) and ventricular arrhythmias (VAs) in T2DM and heart failure patients.

Objectives

To investigate in-hospital new-onset cardiac arrhythmias in a cohort of T2DM patients presenting with acute myocardial infarction (AMI) treated with SGLT2-i vs. other oral anti-diabetic agents (non-SGLT2-i users).

Methods

Patients from the SGLT2-I AMI PROTECT registry (NCT05261867) were stratified according to the use of SGLT2-i before admission for AMI, divided into SGLT2-i users vs. non-SGLT2-i users. In-hospital outcomes included the occurrence of in-hospital new-onset cardiac arrhythmias (NOCAs), defined as a composite of new-onset AF and sustained new-onset ventricular tachycardia (VT) and/or ventricular fibrillation (VF) during hospitalization.

Results

The study population comprised 646 AMI patients categorized into SGLT2-i users (111 patients) and non-SGLT2-i users (535 patients). SGLT2-i users had a lower rate of NOCAs compared with non-SGLT2-i users (6.3 vs. 15.7%, p = 0.010). Moreover, SGLT2-i was associated with a lower rate of AF and VT/VF considered individually (p = 0.032). In the multivariate logistic regression model, after adjusting for all confounding factors, the use of SGLT2-i was identified as an independent predictor of the lower occurrence of NOCAs (OR = 0.35; 95%CI 0.14-0.86; p = 0.022). At multinomial logistic regression, after adjusting for potential confounders, SGLT2-i therapy remained an independent predictor of VT/VF occurrence (OR = 0.20; 95%CI 0.04-0.97; p = 0.046) but not of AF occurrence.

Conclusions

In T2DM patients, the use of SGLT2-i was associated with a lower risk of new-onset arrhythmic events during hospitalization for AMI. In particular, the primary effect was expressed in the reduction of VAs. These findings emphasize the cardioprotective effects of SGLT2-i in the setting of AMI beyond glycemic control.

Trial registration

Data are part of the observational international registry: SGLT2-I AMI PROTECT. ClinicalTrials.gov, identifier: NCT05261867.

Short and long-term prognosis of admission hyperglycemia in patients with and without diabetes after acute myocardial infarction: a retrospective cohort study

OBJECTIVE

Admission hyperglycemia is associated with poor prognosis in patients with acute myocardial infarction (AMI), but the effects of baseline diabetes status on this association remain elusive. We aim to investigate the impact of admission hyperglycemia on short and long-term outcomes in diabetic and non-diabetic AMI patients.

METHODS

In this retrospective cohort study, 3330 patients with regard to first-time AMI between July 2012 and July 2020 were identified. Participants were divided into two groups according to diabetes status (1060 diabetic patients and 2270 non-diabetic patients). Thereafter, they were divided into four groups according to diabetes status-specific cutoff values of fasting blood glucose (FBG) identified by restricted cubic spline. Short-term outcomes included in-hospital death and cardiac complications. Long-term outcomes were all-cause mortality and major adverse cardiovascular events (MACE). Inverse probability of treatment weighting (IPTW) was conducted to adjust for baseline differences among the groups, followed by a weighted Cox proportional hazards regression analysis to calculate hazard ratios and 95% confidence intervals for all-cause mortality associated with each FBG category. Subgroup analysis and sensitivity analysis were performed to test the robustness of our findings.

RESULTS

During a median follow-up of 3.2 years, 837 patients died. There was a significant interaction between diabetes status and FBG levels for all-cause mortality during long-term follow-up (p-interaction < 0.001). Moreover, restricted cubic spline curves for the association between FBG and all-cause mortality followed a J shape in patients with diabetes and a non-linear in patients without diabetes. Kaplan-Meier analysis demonstrated greater survival in non-hyperglycemia patients compared to hyperglycemia patients for both diabetic and non-diabetic patients groups. Survival of hyperglycemia patients without diabetes greater than in hyperglycemia patients with diabetes. In the weighted Multivariable cox analysis, admission hyperglycemia predicted higher short and long-term mortality. Subgroup analysis and sensitivity analysis showed the robustness of the results.

CONCLUSIONS

The inflection points of FBG level for poor prognosis were 5.60 mmol/L for patients without diabetes and 10.60 mmol/L for patients with diabetes. Admission hyperglycemia was identified as an independent predictor of worse short and long-term outcomes in AMI patients, with or without diabetes. These findings should be explored further.

Admission hyperglycemia in acute myocardial infarction is associated with an increased risk of arrhythmias: A systematic review and meta-analysis

Background

Admission hyperglycemia (AH) has shown to be associated with higher mortality rates in acute myocardial infarction (AMI). Malignant arrhythmia is one of the causes of death in AMI; however, it is unclear whether AH is associated with an increased arrhythmia risk. We conducted this systematic review and meta-analysis to assess the association between AH and arrhythmias in AMI.

Methods

We searched MEDLINE, and Embase databases from inception to September 2021 to identify studies that compared arrhythmia rates between AMI patients with AH and those without. Arrhythmias of interest included ventricular tachyarrhythmias (VA), atrial fibrillation (AF), and atrioventricular block.

Results

Thirteen cohort studies with a total of 12,898 patients were included. AH was associated with a higher risk of overall arrhythmias (18% vs 10.3%, pooled odds ratio [OR] = 1.89, 95% confidence interval [CI]: 1.39-2.56, P < .001), VA (16.4% vs 11.1%, pooled OR = 1.56, 95% CI: 1.11-2.18, P = .01), and new onset AF (17.8% vs 6.4%, pooled OR = 2.13, 95% CI: 1.4-3.25, P < .0010. Subgroup analysis of diabetes status regarding overall arrhythmias showed that the increased risk of arrhythmias in the AH group was consistent in both patients with a history of diabetes (18% vs 12.5%, pooled OR = 2.33, 95%CI: 1.2-4.52, P = .004) and without (15.7%. vs 9% pooled OR = 1.35, 95% CI: 1.1-1.66, P = .013).

Conclusion

Admission hyperglycemia in AMI was associated with the increased risk of arrhythmias, regardless of history of diabetes mellitus.

Celebrities in the heart, strangers in the pancreatic beta cell: Voltage-gated potassium channels Kv 7.1 and Kv 11.1 bridge long QT syndrome with hyperinsulinaemia as well as type 2 diabetes

Voltage‐gated potassium (K_v) channels play an important role in the repolarization of a variety of excitable tissues, including in the cardiomyocyte and the pancreatic beta cell. Recently, individuals carrying loss‐of‐function (LoF) mutations in KCNQ1, encoding K_v7.1, and KCNH2 (hERG), encoding K_v11.1, were found to exhibit post‐prandial hyperinsulinaemia and episodes of hypoglycaemia. These LoF mutations also cause the cardiac disorder long QT syndrome (LQTS), which can be aggravated by hypoglycaemia. Interestingly, patients with LQTS also have a higher burden of diabetes compared to the background population, an apparent paradox in relation to the hyperinsulinaemic phenotype, and KCNQ1 has been identified as a type 2 diabetes risk gene. This review article summarizes the involvement of delayed rectifier K⁺ channels in pancreatic beta cell function, with emphasis on K_v7.1 and K_v11.1, using the cardiomyocyte for context. The functional and clinical consequences of LoF mutations and polymorphisms in these channels on blood glucose homeostasis are explored using evidence from pre‐clinical, clinical and genome‐wide association studies, thereby evaluating the link between LQTS, hyperinsulinaemia and type 2 diabetes.

Stability of 1-unit/mL insulin aspart solution in cyclic olefin copolymer vials and polypropylene syringes

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

This study evaluated the stability of diluted insulin aspart solutions (containing insulin aspart and preservatives) at their most commonly used concentration in intensive care units (1 unit/mL), in 2 container types: cyclic olefin copolymer (COC) vials and polypropylene (PP) syringes.

METHODS

Insulin aspart solution (1 unit/mL, diluted in 0.9% sodium chloride injection) was stored for 365 days in COC vials with gray stoppers and PP syringes at refrigerated (5±3°C) and ambient temperatures (25°C ± 2°C at 60% ± 5% relative humidity and protected from light). Chemical testing was conducted monthly using a validated high-performance liquid chromatography method (quantification of insulin aspart, phenol, and metacresol). Physical stability was evaluated monthly via pH measurements, visible and subvisible particle counts, and osmolality measurements. Sterility testing was also performed to validate the sterile preparation process and the maintenance of sterility throughout the study.

RESULTS

The limit of stability was set at 90% of the initial concentrations of insulin aspart, phenol, and metacresol. The physicochemical stability of 1-unit/mL insulin solutions stored refrigerated and protected from light, was unchanged in COC vials for the 365-day period and for 1 month in PP syringes. At ambient temperature, subvisible particulate contamination as well as the chemical stability of insulin and metacresol were acceptable for only 1 month's storage in PP syringes, while insulin chemical stability was maintained for only 3 months' storage in COC vials.

CONCLUSION

According to our results, it is not recommended to administer 1-unit/mL pharmacy-diluted insulin solutions after 3 months' storage in COC vials at ambient temperature or after 1 month in PP syringes at ambient temperature. The findings support storage of 1-unit/mL insulin aspart solution in COC vials at refrigerated temperature as the best option over the long term. Sterility was maintained in every condition. Both sterility and physicochemical stability are essential to authorize the administration of a parenteral insulin solution.

Early and late ventricular arrhythmias complicating ST-segment elevation myocardial infarction

BACKGROUND

Ventricular arrhythmias can be life-threatening complications of ST-segment elevation myocardial infarction (STEMI).

AIMS

To describe the incidence, predictors and in-hospital impact of early ventricular arrhythmia (EVA, occurring<day 2 after STEMI) and late ventricular arrhythmia (LVA, occurring≥day 2 after STEMI) in patients with STEMI.

METHODS

Data from 13,523 patients enrolled in a prospective registry were analysed. Logistic and Cox regressions were performed to identify predictors of EVA, LVA and in-hospital all-cause mortality. Predictors of LVA were used to build a risk score.

RESULTS

EVA occurred in 678 patients (5%), whereas 120 patients (0.9%) experienced LVA, at a median timing of 3days after STEMI. EVA was associated with a significantly higher risk of all-cause mortality (hazard ratio: 1.44, 95% confidence interval: 1.17-1.76; P=0.001), whereas no association was observed with LVA (hazard ratio 0.86, 95% confidence interval 0.57-1.28; P=0.45). Multivariable predictors of LVA were: age≥65years; serum creatinine≥85μmol/L on admission; pulse pressure≤45mmHg on admission; presence of a Q wave on admission electrocardiogram; Thrombolysis In Myocardial Infarction flow grade<3 after percutaneous coronary intervention; and left ventricular ejection fraction≤45%. The score derived from these variables allowed the classification of patients into four risk categories: low (0-21); low-to-intermediate (22-34); intermediate-to-high (35-44); and high (≥45). Observed LVA rates were 0.2%, 0.3%, 0.9% and 2.5%, across the four risk categories, respectively. The model demonstrated good discrimination (20-fold cross-validated c-statistic of 0.76) and adequate calibration (Hosmer-Lemeshow P=0.23).

CONCLUSIONS

EVA is 5-fold more common than LVA in the setting of STEMI, and portends a higher risk of in-hospital all-cause mortality. LVA is mainly associated with the patient's baseline risk profile and surrogate markers of larger infarct size. We developed and internally validated a risk score identifying patients at high risk of LVA for whom early intensive care unit discharge may not be suitable.

Two-hit mechanism of cardiac arrhythmias in diabetic hyperglycaemia: reduced repolarization reserve, neurohormonal stimulation, and heart failure exacerbate susceptibility

AIMS

Diabetic hyperglycaemia is associated with increased arrhythmia risk. We aimed to investigate whether hyperglycaemia alone can be accountable for arrhythmias or whether it requires the presence of additional pathological factors.

METHODS AND RESULTS

Action potentials (APs) and arrhythmogenic spontaneous diastolic activities were measured in isolated murine ventricular, rabbit atrial, and ventricular myocytes acutely exposed to high glucose. Acute hyperglycaemia increased the short-term variability (STV) of action potential duration (APD), enhanced delayed afterdepolarizations, and the inducibility of APD alternans during tachypacing in both murine and rabbit atrial and ventricular myocytes. Hyperglycaemia also prolonged APD in mice and rabbit atrial cells but not in rabbit ventricular myocytes. However, rabbit ventricular APD was more strongly depressed by block of late Na+ current (INaL) during hyperglycaemia, consistent with elevated INaL in hyperglycaemia. All the above proarrhythmic glucose effects were Ca2+-dependent and abolished by CaMKII inhibition. Importantly, when the repolarization reserve was reduced by pharmacological inhibition of K+ channels (either Ito, IKr, IKs, or IK1) or hypokalaemia, acute hyperglycaemia further prolonged APD and further increased STV and alternans in rabbit ventricular myocytes. Likewise, when rabbit ventricular myocytes were pretreated with isoproterenol or angiotensin II, hyperglycaemia significantly prolonged APD, increased STV and promoted alternans. Moreover, acute hyperglycaemia markedly prolonged APD and further enhanced STV in failing rabbit ventricular myocytes.

CONCLUSION

We conclude that even though hyperglycaemia alone can enhance cellular proarrhythmic mechanisms, a second hit which reduces the repolarization reserve or stimulates G protein-coupled receptor signalling greatly exacerbates cardiac arrhythmogenesis in diabetic hyperglycaemia.

Admission Hyperglycemia is Associated with Global Registry of Acute Coronary Events Score and Complications Following Acute Myocardial Infarction During 1-Year Follow-Up

We explored the effect of admission hyperglycemia (AH) on the Global Registry of Acute Coronary Events (GRACE) risk score and major adverse cardiovascular and cerebrovascular event (MACCE) incidence during 1-year follow-up in acute myocardial infarction (AMI) patients. In this retrospective observational study enrolling 1098 AMI patients, hyperglycemia was defined as blood glucose level ≥180 mg/dl at admission. Overall, 158 and 84 patients of 272 diabetic and 826 non-diabetic patients were diagnosed with AH, respectively. Glucose levels at admission were closely associated with the GRACE score in patients with/without diabetes. MACCEs occurred in 222 patients; patients with AH showed significantly higher MACCE incidence (28.1%). Multivariate Cox logistic regression analysis indicated that AH was an independent risk factor for 1-year MACCEs. Subgroup analysis demonstrated that hyperglycemia increases MACCE risk in non-diabetic patients but not in diabetic patients. The admission glucose level combined with GRACE risk score showed a certain predictive value for MACCE incidence according to ROC analysis (OR = 0.798, p < .001). AH was strongly associated with a higher GRACE risk score in ST-segment elevation myocardial infarction patients. Thus, AH was an independent risk factor and had a high predictive value for MACCE during 1-year follow-up after AMI.

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) and cardiac arrhythmias: a systematic review and meta-analysis

Background

Cardiac arrhythmias are associated with poorer outcomes in patients with heart failure (HF), diabetes mellitus (DM), and chronic kidney disease (CKD). Previous studies have shown inconsistent conclusions regarding the association between sodium-glucose cotransporter 2 inhibitors (SGLT2i) and the risk of developing arrhythmias. This study aims to investigate the association of SGLT2i treatment with arrhythmia outcomes in clinical trials of patients with HF, DM, or CKD.

Methods

MEDLINE, EMBASE, and ClinicalTrials.gov were searched from inception up to 27 August 2020. Randomized controlled trials that randomized patients with DM, CKD, or HF to SGLT2i or placebo were included. The outcomes of interest include atrial fibrillation (AF), embolic stroke, atrial flutter (AFL), AF/AFL, ventricular tachycardia (VT), and cardiac arrest. Relative risks (RRs) and 95% confidence intervals (CI) were pooled using a random-effects model.

Results

Out of 4,532 citations, 22 trials with altogether 52,115 patients were included (mean age 63.2 years; 33,747 [64.8%] of participants were men). SGLT2i were associated with a lower risk of AF (RR 0.82, 95% CI 0.70–0.96), embolic stroke (RR 0.32, 95% CI 0.12–0.85), AF/AFL (RR 0.82, 95% CI 0.71–0.95), and VT (RR 0.73, 95% CI 0.53–0.99), while the risk reductions in AFL (RR 0.83, 95% CI 0.58–1.17) and cardiac arrest (RR 0.83, 95% CI 0.61–1.14) did not reach statistical significance. The associations appeared to be consistent across different baseline conditions (DM vs CKD vs HF; atherosclerotic cardiovascular disease [ASCVD] vs no ASCVD) and the SGLT2i used.

Conclusions

SGLT2i reduced the risk of cardiac arrhythmias. Our study provides further evidence for recommending the use of SGLT2i in patients with DM, CKD, and HF. Further research is needed to fully elucidate the mechanism by which SGLT2i protect against arrhythmias.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01293-8.

Cardiac arrhythmias and electrophysiologic responses during spontaneous hyperglycaemia in adults with type 1 diabetes mellitus

AIM

We examined the effect of spontaneous hyperglycaemia in adults with type 1 diabetes mellitus (T1DM) and without history of cardiovascular disease on heart rate variability (HRV), cardiac repolarisation and incidence of cardiac arrhythmias.

METHODS

Thirty-seven individuals with T1DM (age 17-50 years, 19 males, mean duration of diabetes 19.3 SD(9.6) years) underwent 96 h of simultaneous ambulatory 12-lead Holter ECG and blinded continuous interstitial glucose (IG) monitoring (CGM). HRV, QT interval and cardiac repolarisation were assessed during hyperglycaemia (IG ≥ 15 mmol/l) and compared with matched euglycaemia (IG 5-10 mmol/l) on a different day, separately during the day and night. Rates of arrhythmias were assessed by calculating incidence rate differences.

RESULTS

Simultaneous ECG and CGM data were recorded for 2395 hours. During daytime hyperglycaemia vs euglycaemia the mean QT_c interval duration was 404 SD(21)ms vs 407 SD(20)ms, P = 0.263. T-peak to T-end interval duration corrected for heart rate (T_pT_endc) shortened: 74.8 SD(16.1)ms vs 79.0 SD(14.8)ms, P = 0.033 and T-wave symmetry increased: 1.62 SD(0.33) vs 1.50 SD(0.39), P = 0.02. During night-time hyperglycaemia vs euglycaemia, the mean QT_c interval duration was 401 SD(26)ms vs 404 SD(27)ms, P = 0.13 and T_pT_end shortened: 62.4 SD(12.0)ms vs 67.1 SD(11.8)ms, P = 0.003. The number of cardiac arrhythmias was low and confined to bradycardia and isolated ectopic beats. A considerable inter-subject and diurnal variability was observed.

CONCLUSIONS

Hyperglycaemia in individuals with T1DM without known cardiovascular disease was not associated with clinically important cardiac arrhythmias.

The U-Shape Relationship Between Glycated Hemoglobin Level and Long-Term All-Cause Mortality Among Patients With Coronary Artery Disease

Background: Although glycated hemoglobin (HbA1c) was considered as a prognostic factor in some subgroup of coronary artery disease (CAD), the specific relationship between HbA1c and the long-term all-cause death remains controversial in patients with CAD.

Methods: The study enrolled 37,596 CAD patients and measured HbAlc at admission in Guangdong Provincial People's Hospital. The patients were divided into 4 groups according to HbAlc level (Quartile 1: HbA1c ≤ 5.7%; Quartile 2: 5.7% < HbA1c ≤ 6.1%; Quartile 3: 6.1% < HbA1c ≤ 6.7%; Quartile 4: HbA1c > 6.7%). The study endpoint was all-cause death. The restricted cubic splines and cox proportional hazards models were used to investigate the association between baseline HbAlc levels and long-term all-cause mortality.

Results: The median follow-up was 4 years. The cox proportional hazards models revealed that HbAlc is an independent risk factor in the long-term all-cause mortality. We also found an approximate U-shape association between HbA1c and the risk of mortality, including increased risk of mortality when HbA1c ≤ 5.7% and HbA1c > 6.7% [Compared with Quartile 2, Quartile 1 (HbA1c ≤ 5.7), aHR = 1.13, 95% CI:1.01–1.26, P < 0.05; Quartile 3 (6.1% < HbA1c ≤ 6.7%), aHR = 1.04, 95% CI:0.93–1.17, P =0.49; Quartile 4 (HbA1c > 6.7%), aHR = 1.32, 95% CI:1.19–1.47, P < 0.05].

Conclusions: Our study indicated a U-shape relationship between HbA1c and long-term all-cause mortality in CAD patients.

Hyperglycemia regulates cardiac K+ channels via O-GlcNAc-CaMKII and NOX2-ROS-PKC pathways

Chronic hyperglycemia and diabetes lead to impaired cardiac repolarization, K⁺ channel remodeling and increased arrhythmia risk. However, the exact signaling mechanism by which diabetic hyperglycemia regulates cardiac K⁺ channels remains elusive. Here, we show that acute hyperglycemia increases inward rectifier K⁺ current (I_K1), but reduces the amplitude and inactivation recovery time of the transient outward K⁺ current (I_to) in mouse, rat, and rabbit myocytes. These changes were all critically dependent on intracellular O-GlcNAcylation. Additionally, I_K1 amplitude and I_to recovery effects (but not I_to amplitude) were prevented by the Ca²⁺/calmodulin-dependent kinase II (CaMKII) inhibitor autocamtide-2-related inhibitory peptide, CaMKIIδ-knockout, and O-GlcNAc-resistant CaMKIIδ-S280A knock-in. I_to reduction was prevented by inhibition of protein kinase C (PKC) and NADPH oxidase 2 (NOX2)-derived reactive oxygen species (ROS). In mouse models of chronic diabetes (streptozotocin, db/db, and high-fat diet), heart failure, and CaMKIIδ overexpression, both I_to and I_K1 were reduced in line with the downregulated K⁺ channel expression. However, I_K1 downregulation in diabetes was markedly attenuated in CaMKIIδ-S280A. We conclude that acute hyperglycemia enhances I_K1 and I_to recovery via CaMKIIδ-S280 O-GlcNAcylation, but reduces I_to amplitude via a NOX2-ROS-PKC pathway. Moreover, chronic hyperglycemia during diabetes and CaMKII activation downregulate K⁺ channel expression and function, which may further increase arrhythmia susceptibility.

Effects of metformin on atrial and ventricular arrhythmias: evidence from cell to patient

Metformin has been shown to have various cardiovascular benefits beyond its antihyperglycemic effects, including a reduction in stroke, heart failure, myocardial infarction, cardiovascular death, and all-cause mortality. However, the roles of metformin in cardiac arrhythmias are still unclear. It has been shown that metformin was associated with decreased incidence of atrial fibrillation in diabetic patients with and without myocardial infarction. This could be due to the effects of metformin on preventing the structural and electrical remodeling of left atrium via attenuating intracellular reactive oxygen species, activating 5′ adenosine monophosphate-activated protein kinase, improving calcium homeostasis, attenuating inflammation, increasing connexin-43 gap junction expression, and restoring small conductance calcium-activated potassium channels current. For ventricular arrhythmias, in vivo reports demonstrated that activation of 5′ adenosine monophosphate-activated protein kinase and phosphorylated connexin-43 by metformin played a key role in ischemic ventricular arrhythmias reduction. However, metformin failed to show anti-ventricular arrhythmia benefits in clinical trials. In this review, in vitro and in vivo reports regarding the effects of metformin on both atrial arrhythmias and ventricular arrhythmias are comprehensively summarized and presented. Consistent and controversial findings from clinical trials are also summarized and discussed. Due to limited numbers of reports, further studies are needed to elucidate the mechanisms and effects of metformin on cardiac arrhythmias. Furthermore, randomized controlled trials are needed to clarify effects of metformin on cardiac arrhythmias in human.

General glycosylated hemoglobin goals potentially increase myocardial infarction severity in diabetes patients with comorbidities: Insights from a nationwide multicenter study

AIMS/INTRODUCTION

We aimed to investigate the relationship between glycemic status and coronary artery disease (CAD) extent and severity in ST-elevation myocardial infarction (STEMI) patients, and further examine whether diabetes patients could benefit from glycosylated hemoglobin (HbA1c) below the recommended level.

MATERIALS AND METHODS

Consecutive STEMI patients admitted in 2015-2017 across 244 hospitals were included in the China STEMI Care Project-2. We carried out a cross-sectional study comprising 8,370 participants with a record of HbA1c testing after admission. CAD extent and severity were assessed by admission heart rate, Killip classification and the number of stenosed vessels based on the coronary angiogram.

RESULTS

Diabetes patients showed a greater risk for higher Killip class, admission tachycardia (admission heart rate ≥100 b.p.m.) and multivessel CAD (presence of left main and/or triple vessel disease). Likewise, HbA1c level was significantly associated with CAD extent and severity. While dividing diabetes patients according to general HbA1c targets (HbA1c ≤6.5, 6.5-7.0 and ≥7.0%), diabetes patients with HbA1c ≤6.5% showed a 1.30-fold higher risk for multivessel CAD (adjusted odds ratio 1.30, 95% confidence interval 1.05-1.62). In stratified analysis, the association was even stronger in patients with hypertension (adjusted odds ratio 1.41, 95% confidence interval 1.08-1.86) or hyperlipidemia (adjusted odds ratio 1.57, 95% confidence interval 1.17-2.12).

CONCLUSIONS

HbA1c level is independently correlated with CAD extent and severity in STEMI patients. HbA1c below generally recommended levels might still increase the risk of CAD progression, especially for diabetes patients with hypertension or hyperlipidemia.

Effects of empagliflozin versus placebo on cardiac sympathetic activity in acute myocardial infarction patients with type 2 diabetes mellitus: the EMBODY trial

Background

Protection from lethal ventricular arrhythmias leading to sudden cardiac death (SCD) is a crucial challenge after acute myocardial infarction (AMI). Cardiac sympathetic and parasympathetic activity can be noninvasively assessed using heart rate variability (HRV) and heart rate turbulence (HRT). The EMBODY trial was designed to determine whether the Sodium–glucose cotransporter 2 (SGLT2) inhibitor improves cardiac nerve activity.

Methods

This prospective, multicenter, randomized, double-blind, placebo-controlled trial included patients with AMI and type 2 diabetes mellitus (T2DM) in Japan; 105 patients were randomized (1:1) to receive once-daily 10-mg empagliflozin or placebo. The primary endpoints were changes in HRV, e.g., the standard deviation of all 5-min mean normal RR intervals (SDANN) and the low-frequency–to–high-frequency (LF/HF) ratio from baseline to 24 weeks. Secondary endpoints were changes in other sudden cardiac death (SCD) surrogate markers such as HRT.

Results

Overall, 96 patients were included (46, empagliflozin group; 50, placebo group). The changes in SDANN were + 11.6 and + 9.1 ms in the empagliflozin (P = 0.02) and placebo groups (P = 0.06), respectively. Change in LF/HF ratio was – 0.57 and – 0.17 in the empagliflozin (P = 0.01) and placebo groups (P = 0.43), respectively. Significant improvement was noted in HRT only in the empagliflozin group (P = 0.01). Whereas intergroup comparison on HRV and HRT showed no significant difference between the empagliflozin and placebo groups. Compared with the placebo group, the empagliflozin group showed significant decreases in body weight, systolic blood pressure, and uric acid. In the empagliflozin group, no adverse events were observed.

Conclusions

This is the first randomized clinical data to evaluate the effect of empagliflozin on cardiac sympathetic and parasympathetic activity in patients with T2DM and AMI. Early SGLT2 inhibitor administration in AMI patients with T2DM might be effective in improving cardiac nerve activity without any adverse events.

Trial Registration: The EMBODY trial was registered by the UMIN in November 2017 (ID: 000030158). UMIN000030158; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034442.

High admission glucose levels predict worse short-term clinical outcome in non-diabetic patients with acute myocardial infraction: a retrospective observational study

BACKGROUND

Patients with acute myocardial infarction (AMI) often accompanied by admission hyperglycemia, which usually predicts a poor clinical outcomes for non-diabetes mellitus. Appropriate cut-point to identify high risk individuals in these patients remains controversial.

METHODS

One thousand six hundred ninety-eight non-diabetes AMI patients in this retrospective study were divided into 3 groups according to admission glucose levels (euglycemia group≤140 mg/dL, moderate hyperglycemia group 141-179 mg/dL, severe hyperglycemia group≥180 mg/dL). The primary endpoint of this study was all-cause in-hospital mortality rate. In-hospital motality related risk factors was analyzed by multivariate binary logistic regression analyses.

RESULTS

All myocardial necrosis markers and Log NT-proBNP in severe hyperglycemia group were significantly higher than those in the other 2 groups. Logistic regression showed that independent predictors of the in-hospital mortality rate in non-diabetic patients with AMI were age (OR = 1.057, 95% CI 1.024-1.091, P < 0.001), logarithm of the N-terminal pro-brain natriuretic peptide (OR = 7.697, 95% CI 3.810-15.550, P < 0.001), insufficient myocardial reperfusion (OR = 7.654, 95% CI 2.109-27.779, P < 0.001), percutaneous coronary intervention (OR = 0.221, 95% CI 0.108-0.452, P < 0.001) and admission glucose (as categorical variable). Patients with moderate hyperglycemia (OR = 1.186, 95% CI 0.585-2.408, P = .636) and severe hyperglycemia (OR = 4.595, 95% CI 1.942-10.873, P = 0.001) had a higher all-cause in-hospital mortality rate compared with those with euglycemia after AMI in non-diabetic patients.

CONCLUSIONS

The all-cause in-hospital mortality risk increases remarkably as admission glucose levels elevated in non-diabetic patients with AMI, especially in patients with admission glucose levels ≥180 mg/dL. Severe admission hyperglycemia could be regarded as prospective high-risk marker for non-diabetic AMI patients.

Increased glucose variability is associated with atrial fibrillation after coronary artery bypass

BACKGROUND

Elevated preoperative hemoglobin A1c (HbA1c) is a predictor of poor outcomes following coronary artery bypass grafting (CABG), but the role of increased postoperative glucose variability (GV) is unknown. We hypothesized that short-term postoperative GV is associated with an increased risk of postoperative atrial fibrillation following isolated CABG.

METHODS

Multicenter retrospective study of 2073 patients who underwent isolated CABG from January 2012 to March 2018. Postoperative GV in the first 24 hours was measured by standard deviation, coefficient of variation, and mean amplitude of glycemic excursions. Multivariate logistic regression assessed the independent association of GV with postoperative atrial fibrillation.

RESULTS

A total of 2073 patients met the study criteria, and 446 patients (21.5%) developed postoperative atrial fibrillation. Using multivariate logistic regression to adjust for covariates, postoperative atrial fibrillation was associated with increased 24-hour GV (odds ratio [OR] = 1.16, 95% confidence interval [CI], 1.05-1.27, P < 0.01) and increased 24-hour mean glucose (OR = 1.14, 95% CI, 1.08-1.21, P < 0.01). Thus, for every 10% increase in 24-hour GV or 10 mg/dL increase in mean glucose, there was a 16% or 14% increased risk of postoperative atrial fibrillation respectively.

CONCLUSIONS

Increased 24-hour GV and mean glucose are predictors of atrial fibrillation after CABG. Preoperative HbA1c is not a risk factor for postoperative atrial fibrillation after adjusting for postoperative mean glucose and GV. Further investigation is needed to determine the relationship between adherence to strict glucose control and adverse events following CABG.