Diabetes, glucose level, and risk of sudden cardiac death

Accuracy and Functionality of Select Continuous Glucose Monitoring Systems Are Not Impacted by Implantable Cardioverter Defibrillator Devices

BACKGROUND

Increasing numbers of individuals with diabetes are adopting use of continuous glucose monitoring (CGM) in their daily self-management. Many of these individuals have advanced heart disease. Implantable cardioverter defibrillator (ICD) devices can effectively reduce arrhythmic death and all-cause mortality in individuals with advanced heart disease. However, the potential impact of ICD devices on CGM system accuracy and functionality has not been well studied.

METHODS

This evaluation assessed whether FreeStyle Libre (FL) CGM systems can coexist and function within the same patient in the presence of wireless interference devices, including current ICD devices. Interferer sources included Wi-Fi devices, Bluetooth devices, cellular mobile devices, implantable medical devices, Bluetooth Low-Energy (BLE) devices, BLE accessory devices and BLE mobile devices, and ICD-programmer interferers. Five testing methodologies were used to evaluate the accuracy and functionality of the CGM systems when exposed to ICD functions: high-energy emergency shocking, pacing modes, anti-tachycardia pacing mode (ATP), and DC Fibber mode.

RESULTS

All acceptance criteria and testing requirements were met for the CGM and ICD system for wireless coexistence evaluation.

CONCLUSIONS

Our findings demonstrated that coexisting ICD devices and FL CGM systems provide safe and effective wireless communications with functional and accurate transfer of data during scenarios expected in clinical use.

The Biomedical Applications of Biomolecule Integrated Biosensors for Cell Monitoring

Cell monitoring is essential for understanding the physiological conditions and cell abnormalities induced by various stimuli, such as stress factors, microbial invasion, and diseases. Currently, various techniques for detecting cell abnormalities and metabolites originating from specific cells are employed to obtain information on cells in terms of human health. Although the states of cells have traditionally been accessed using instrument-based analysis, this has been replaced by various sensor systems equipped with new materials and technologies. Various sensor systems have been developed for monitoring cells by recognizing biological markers such as proteins on cell surfaces, components on plasma membranes, secreted metabolites, and DNA sequences. Sensor systems are classified into subclasses, such as chemical sensors and biosensors, based on the components used to recognize the targets. In this review, we aim to outline the fundamental principles of sensor systems used for monitoring cells, encompassing both biosensors and chemical sensors. Specifically, we focus on biosensing systems in terms of the types of sensing and signal-transducing elements and introduce recent advancements and applications of biosensors. Finally, we address the present challenges in biosensor systems and the prospects that should be considered to enhance biosensor performance. Although this review covers the application of biosensors for monitoring cells, we believe that it can provide valuable insights for researchers and general readers interested in the advancements of biosensing and its further applications in biomedical fields.

Sudden cardiac death due to ventricular arrhythmia in diabetes mellitus: A bench to bedside review

Diabetes mellitus (DM) confers an increased risk of sudden cardiac death (SCD) independent of its associated cardiovascular comorbidities. DM induces adverse structural, electrophysiologic, and autonomic cardiac remodeling that can increase one's risk of ventricular arrhythmias and SCD. Although glycemic control and prevention of microvascular and macrovascular complications are cornerstones in the management of DM, they are not adequate for the prevention of SCD. In this narrative review, we describe the contribution of DM to the pathophysiologic mechanism of SCD beyond its role in atherosclerotic cardiovascular disease and heart failure. On the basis of this pathophysiologic framework, we outline potential preventive and therapeutic strategies to mitigate the risk of SCD in this population of high-risk patients.

QRS-T angle: is it a specific parameter associated with sudden cardiac death in type 2 diabetes? Results from the SURDIAGENE and the Mini-Finland prospective cohorts

AIMS/HYPOTHESIS

Type 2 diabetes is associated with a high risk of sudden cardiac death (SCD), but the risk of dying from another cause (non-SCD) is proportionally even higher. The aim of the study was to identify easily available ECG-derived features associated with SCD, while considering the competing risk of dying from non-SCD causes.

METHODS

In the SURDIAGENE (Survie, Diabete de type 2 et Genetique) French prospective cohort of individuals with type 2 diabetes, 15 baseline ECG parameters were interpreted among 1362 participants (mean age 65 years; HbA1c 62±17 mmol/mol [7.8±1.5%]; 58% male). Competing risk models assessed the prognostic value of clinical and ECG parameters for SCD after adjusting for age, sex, history of myocardial infarction, N-terminal pro b-type natriuretic peptide (NT-proBNP), HbA1c and eGFR. The prospective Mini-Finland cohort study was used to externally validate our findings.

RESULTS

During median follow-up of 7.4 years, 494 deaths occurred including 94 SCDs. After adjustment, frontal QRS-T angle ≥90° (sub-distribution HR [sHR] 1.68 [95% CI 1.04, 2.69], p=0.032) and NT-proBNP level (sHR 1.26 [95% CI 1.06, 1.50] per 1 log, p=0.009) were significantly associated with a higher risk of SCD. Nevertheless, frontal QRS-T angle was the only marker not to be associated with causes of death other than SCD (sHR 1.08 [95% CI 0.84, 1.39], p=0.553 ). These findings were replicated in the Mini-Finland study subset of participants with diabetes (sHR 2.22 [95% CI 1.05, 4.71], p=0.04 for SCD and no association for other causes of death).

CONCLUSIONS/INTERPRETATION

QRS-T angle was specifically associated with SCD risk and not with other causes of death, opening an avenue for refining SCD risk stratification in individuals with type 2 diabetes.

The Role of Cilostazol, a Phosphodiesterase-3 Inhibitor, in the Development of Atherosclerosis and Vascular Biology: A Review with Meta-Analysis

Atherosclerotic cardiovascular disease (ASCVD) stands as the leading global cause of mortality. Addressing this vital and pervasive condition requires a multifaceted approach, in which antiplatelet intervention plays a pivotal role, together with antihypertensive, antidiabetic, and lipid-lowering therapies. Among the antiplatelet agents available currently, cilostazol, a phosphodiesterase-3 inhibitor, offers a spectrum of pharmacological effects. These encompass vasodilation, the impediment of platelet activation and aggregation, thrombosis inhibition, limb blood flow augmentation, lipid profile enhancement through triglyceride reduction and high-density lipoprotein cholesterol elevation, and the suppression of vascular smooth muscle cell proliferation. However, the role of cilostazol has not been clearly documented in many guidelines for ASCVD. We comprehensively reviewed the cardiovascular effects of cilostazol within randomized clinical trials that compared it to control or active agents and involved individuals with previous coronary artery disease or stroke, as well as those with no previous history of such conditions. Our approach demonstrated that the administration of cilostazol effectively reduced adverse cardiovascular events, although there was less evidence regarding its impact on myocardial infarction. Most studies have consistently reported its favorable effects in reducing intermittent claudication and enhancing ambulatory capacity in patients with peripheral arterial disease. Furthermore, cilostazol has shown promise in mitigating restenosis following coronary stent implantation in patients with acute coronary syndrome. While research from more diverse regions is still needed, our findings shed light on the broader implications of cilostazol in the context of atherosclerosis and vascular biology, particularly for individuals at high risk of ASCVD.

Effects of hyperglycemia on the TGF-β pathway in trabecular meshwork cells

BACKGROUND

Hyperglycemia, which can lead to apoptosis, hypertrophy, fibrosis, and induces hyperinflammation in diabetic vascular complications due to oxidative stress. In order to elucidate the potential dual roles and regulatory signal transduction of TGF-β1 and TGF-β2 in human trabecular meshwork cells (HTMCs), we established an oxidative cell model in HTMCs using 5.5, 25, 50, and 100 mM d-glucose-supplemented media and characterized the TGF-β-related oxidative stress pathway.

METHODS

Further analysis was conducted to investigate oxidative damage and protein alterations in the HTMC caused by the signal transduction. This was done through a series of qualitative cell function studies, such as cell viability/apoptosis analysis, intracellular reactive oxygen species (ROS) detection, analysis of calcium release concentration, immunoblot analysis to detect the related protein expression alteration, and analysis of cell fibrosis to study the effect of different severities of hyperglycemia. Also, we illustrated the role of TGF-β1/2 in oxidative stress-induced injury by shRNA-mediated knockdown or stimulation with recombinant human TGF-β1 protein (rhTGF-β1).

RESULTS

Results from the protein expression analysis showed that p-JNK, p-p38, p-AKT, and related SMAD family members were upregulated in HTMCs under hyperglycemia. In the cell functional assays, HTMCs treated with rhTGFβ-1 (1 ng/mL) under hyperglycemic conditions showed higher proliferation rates and lower ROS and calcium levels.

CONCLUSIONS

To summarize, mechanistic analyses in HTMCs showed that hyperglycemia-induced oxidative stress activated TGF-β1 along with its associated pathway.

GENERAL SIGNIFICANCE

While at low concentrations, TGF-β1 protects cells from antioxidation, whereas at high concentrations, it accumulates in the extracellular matrix, causing further HTMC dysfunction.

Association of temporal change in body mass index with sudden cardiac arrest in diabetes mellitus

BACKGROUND

Underweight imposes significant burden on cardiovascular outcomes in patients with diabetes mellitus. However, less is known about the impact of serial change in body weight status measured as body mass index (BMI) on the risk of sudden cardiac arrest (SCA). This study investigated the association between SCA and temporal change in BMI among patients with diabetes mellitus.

METHODS

Based on Korean National Health Insurance Service database, participants with diabetes mellitus who underwent health examination between 2009 and 2012 and had prior health examination data (four years ago, 2005-2008) were retrospectively analyzed. BMI was measured at baseline (2005-2008) and 4-year follow-up health examination (2009-2012). Patients were classified in four groups according to the body weight status and its temporal change: sustained non-underweight, sustained underweight, previous underweight, and newly developed underweight. Primary outcome was defined as occurrence of SCA.

RESULTS

A total of 1,355,746 patients with diabetes mellitus were included for analysis, and SCA occurred in 12,554 cases. SCA was most common in newly developed underweight (incidence rate = 4.45 per 1,000 person-years), followed by sustained underweight (incidence rate = 3.90), previous underweight (incidence rate = 3.03), and sustained non-underweight (incidence rate = 1.34). Adjustment of covariates resulted highest risk of SCA in sustained underweight (adjusted hazard ratio = 2.60, 95% confidence interval [2.25-3.00], sustained non-underweight as a reference), followed by newly developed underweight (2.42, [2.15-2.74]), and previous underweight (2.12, [1.77-2.53]).

CONCLUSIONS

In diabetes mellitus, sustained underweight as well as decrease in body weight during 4-year follow-up imposes substantial risk on SCA. Recovery from underweight over time had relatively lower, but yet increased risk of SCA. Both underweight and dynamic decrease in BMI can be associated with increased risk of SCA.

Implantable cardioverter defibrillator and cardiac resynchronization treatment in people with type 2 diabetes: a comparison with age- and sex matched controls from the general population

BACKGROUND

Increased risk of severe tachyarrhythmias is reported in patients with type 2 diabetes mellitus (T2DM). The aim of this study was to explore if treatment with cardiac implantable electronic device (CIED) such as implantable cardioverter defibrillator (ICD), cardiac resynchronization therapy- pacemaker and -defibrillator (CRT-P/CRT-D) differed in patients with vs. without T2DM. A secondary aim was to identify patient characteristics indicating an increased CIED treatment.

METHOD

416 162 adult patients with T2DM from the Swedish National Diabetes Registry and 2 081 087 controls from the Swedish population, matched for age, sex and living area, were included between 1/1/1998 and 31/12/2012 and followed until 31/12/2013. They were compared regarding prevalence of ventricular tachycardia (VT) at baseline and the risk of receiving a CIED during follow-up. Multivariable Cox regression analysis was performed to estimate the risk of CIED-treatment and factors identifying patients with such risk.

RESULTS

Ventricular fibrillation (VF) (0.1% vs 0.0004%) and (VT) (0.2% vs. 0.1%) were more frequent among patients with T2DM compared to controls. CIED-treatment was significantly increased in patients with T2DM both in unadjusted and adjusted analyses. HR and 95% CI, after adjustment for sex, age, marital status, income, education, country of birth, coronary artery disease and congestive heart failure, were 1.32 [1.21-1.45] for ICD, 1.74 [1.55-1.95] for CRT-P and 1.69 [1.43-1.99] for CRT-D. Blood-pressure and lipid lowering therapies were independent risk factors associated to receiving CIED, while female sex was protective.

CONCLUSIONS

Although the proportion of VT/VF was low, patients with T2DM had a higher prevalence of these conditions and increased risk for treatment with CIED compared to controls. This underlines the importance of recognizing that T2DM patients have an increased need of CIED.

Strong independent association between third-degree AV-block and diabetes mellitus using a large database

BACKGROUND

Recent data suggests an association between DM and third-degree AV- Block. The goal of this study was to evaluate the independent association between diabetes and third-degree AV-Block using a very large database.

METHOD

We used ICD-9 Codes for DM and third-degree AV-block from the Nationwide Inpatient Sample (NIS) database. We randomly selected the 1992 and 2002 databases which are 10 years apart as two independent samples. We used uni- and multi-variate analysis to evaluate this association.

RESULTS

1992 database contained a total of 6,195,744 patients. Diabetes occurred in (0.5 %) of patients with third-degree AV-block vs. (0.2 %) of the control (OR: 2.15, CI 2.06-2.25, p < 0.0001). 2002 database contained a total of 7,853,982 patients. Diabetes occurred in (0.4 %) of patients with third-degree AV-block vs. (0.2 %) of the control (OR: 1.86, CI: 1.80-1.93, p < 0.0001). Using Multivariate analysis adjusting for age, congestive heart failure, and coronary artery disease, DM remained independently associated with third-degree AV block in both databases. (for 1999: OR: 2.54, CI 2.51-2.57, p < 0.0001 and for 2002 OR: 1.56, CI 1.55-1.57, p < 0.0001).

CONCLUSION

DM is independently associated with third-degree AV-block with persistent association over a period of 10 years. The cause of this association warrants further investigation.

Associations between Inflammation, Hemoglobin Levels, and Coronary Artery Disease in Non-Albuminuric Subjects with and without Type 2 Diabetes Mellitus

In this cross-sectional study, we evaluated the associations of inflammation and hemoglobin with coronary artery disease (CAD) in subjects with type 2 diabetes mellitus (T2DM) and preserved kidney function. We recruited 638 participants-254 with T2DM-subjected to coronary angiography with no known cardiovascular disease, normal glomerular filtration rates, and without albuminuria. The hemoglobin and serum levels of inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), were measured. Multivariable analyses showed that inflammatory markers were not related to the severity of the stenosis in the group of subjects with diabetes. Conversely, inflammatory cytokines and albuminuria were directly related to the percentage of stenosis in subjects without T2DM (R2 = 0.038, p < 0.001). Patients with diabetes presented lower hemoglobin levels, particularly in those who also had significant CAD (14.4 [13.6-15.1] vs. 13.6 [12.2-14.8] g/dL, p = 0.03). Similarly, hemoglobin levels and albuminuria were inversely related to the severity of stenosis exclusively in subjects with diabetes, even after adjusting for multiple confounding factors (R2 = 0.081, p < 0.001). We conclude that reductions in hemoglobin levels in subjects with T2DM and normoalbuminuria may constitute a more relevant risk factor for CAD than inflammation.

The Lancet Commission to reduce the global burden of sudden cardiac death: a call for multidisciplinary action

Despite major advancements in cardiovascular medicine, sudden cardiac death (SCD) continues to be an enormous medical and societal challenge, claiming millions of lives every year. Efforts to prevent SCD are hampered by imperfect risk prediction and inadequate solutions to specifically address arrhythmogenesis. Although resuscitation strategies have witnessed substantial evolution, there is a need to strengthen the organisation of community interventions and emergency medical systems across varied locations and health-care structures. With all the technological and medical advances of the 21st century, the fact that survival from sudden cardiac arrest (SCA) remains lower than 10% in most parts of the world is unacceptable. Recognising this urgent need, the Lancet Commission on SCD was constituted, bringing together 30 international experts in varied disciplines. Consistent progress in tackling SCD will require a completely revamped approach to SCD prevention, with wide-sweeping policy changes that will empower the development of both governmental and community-based programmes to maximise survival from SCA, and to comprehensively attend to survivors and decedents' families after the event. International collaborative efforts that maximally leverage and connect the expertise of various research organisations will need to be prioritised to properly address identified gaps. The Commission places substantial emphasis on the need to develop a multidisciplinary strategy that encompasses all aspects of SCD prevention and treatment. The Commission provides a critical assessment of the current scientific efforts in the field, and puts forth key recommendations to challenge, activate, and intensify efforts by both the scientific and global community with new directions, research, and innovation to reduce the burden of SCD worldwide.

Outcomes after out-of-hospital cardiac arrest in immigrants vs natives in Denmark

AIMS

Ethnic disparities subsist in out-of-hospital cardiac arrest (OHCA) outcomes in the US, yet it is unresolved whether similar inequalities exist in European countries. This study compared survival after OHCA and its determinants in immigrants and non-immigrants in Denmark.

METHODS

Using the nationwide Danish Cardiac Arrest Register, 37,622 OHCAs of presumed cardiac cause between 2001 and 2019 were included, 95% in non-immigrants and 5% in immigrants. Univariate and multiple logistic regression was used to assess disparities in treatments, return of spontaneous circulation (ROSC) at hospital arrival, and 30-day survival.

RESULTS

Immigrants were younger at OHCA (median 64 [IQR 53-72] vs 68 [59-74] years; p < 0.05), had more prior myocardial infarction (15% vs 12%, p < 0.05), more diabetes (27% vs 19%, p < 0.05), and were more often witnessed (56% vs 53%; p < 0.05). Immigrants received similar bystander cardiopulmonary resuscitation and defibrillation rates to non-immigrants, but more coronary angiographies (15% vs 13%; p < 0.05) and percutaneous coronary interventions (10% vs 8%, p < 0.05), although this was insignificant after age-adjustment. Immigrants had higher ROSC at hospital arrival (28% vs 26%; p < 0.05) and 30-day survival (18% vs 16%; p < 0.05) compared to non-immigrants, but adjusting for age, sex, witness status, first observed rhythm, diabetes, and heart failure rendered the difference non-significant (odds ratios (OR) 1.03, 95% confidence interval (CI) 0.92-1.16 and OR 1.05, 95% CI 0.91-1.20, respectively).

CONCLUSIONS

OHCA management was similar between immigrants and non-immigrants, resulting in similar ROSC at hospital arrival and 30-day survival after adjustments.

Association of Klotho with Coronary Artery Disease in Subjects with Type 2 Diabetes Mellitus and Preserved Kidney Function: A Case-Control Study

Circulating Klotho levels are significantly reduced in subjects with type 2 diabetes mellitus (T2DM) and in kidney disease patients. In this work, the relationship between Klotho levels and the coronary artery disease (CAD) burden in subjects with T2DM and preserved kidney function was analyzed. For this, we performed a cross-sectional case-control study involving 133 subjects with T2DM and 200 age-, sex- and CAD-incidence-matched, non-diabetic patients undergoing non-emergency diagnostic coronary angiography. All of them were non-albuminuric and with normal glomerular filtration rates. The concentrations of serum Klotho, fibroblast growth factor 23, and inflammatory markers were also measured. As expected, the serum Klotho concentration was lower in the T2DM group (12.3% lower, p = 0.04). However, within the group of patients with T2DM, those subjects with CAD presented significantly higher Klotho levels than those without significant coronary stenosis (314.5 (6.15-562.81) vs. 458.97 (275.2-667.2) pg/mL; p = 0.02). Multiple regression analysis revealed that serum Klotho was positively related with stenosis values exclusively in subjects with T2DM (adjusted R2 = 0.153, p < 0.01). Moreover, logistic regression analysis showed that Klotho was positively associated with the presence of significant CAD in the group of T2DM patients (OR: 1.001; p = 0.041). Our data suggest that higher levels of circulating Klotho in subjects with T2DM and preserved kidney function are associated with the presence of significant CAD.

The effect of dapagliflozin therapy on ventricular repolarization parameters in electrocardiography in patients with diabetic cardiovascular disease

BACKGROUND

Dapagliflozin is an agent that has both antihyperglycemic effects and is significantly associated with a lower risk of cardiovascular events in patients with diabetes mellitus (DM). However, there is insufficient data and information about the effect of dapagliflozin on electrocardiographic (ECG) parameters.

AIM

The effects of dapagliflozin on ventricular repolarization parameters have not been fully elucidated yet. This study aimed to investigate whether dapagliflozin has a positive effect on ventricular repolarization heterogeneity parameters in patients with type 2 DM.

METHOD

We retrospectively enrolled 140 patients with a known diagnosis of type 2 DM who were newly prescribed dapagliflozin in addition to standard anti-diabetic therapy. The patients were divided into two groups according to whether they had cardiovascular disease (CVD). The effect of dapagliflozin treatment on ventricular repolarization parameters (frontal plane QRST angle, Tp-e interval, Tp-e/QTc, QTc, and QTc dispersion) was investigated, patient groups were compared before and after treatment.

RESULTS

Among 140 patients, 70 (50 %) had CVD and 70 (50 %) did not have CVD. Dapagliflozin treatment resulted in significant reductions in ventricular repolarization parameters over the study period in the CVD group with diabetes. Mean fQRST angle, Tp-e interval, Tp-e/QTc, QTc, and QTc dispersion were significantly lower than baseline values at 6-month follow-up visits in the CVD group (61.61 ± 9.22° vs 52.55 ± 8.31°, 74.45 ± 16.06 msec vs 63.27 ± 13.99 msec, 0.19 ± 0.03 vs 0.16 ± 0.03, 384.12 ± 47.93 msec vs 356.15 ± 43.31 mesc, 55.28 ± 5.50 msec vs 48.08 ± 6.48 msec for all pairwise comparisons p < 0.001).

CONCLUSION

Similar antihyperglycemic effects were found with dapagliflozin treatment in patients with and without CVD. However, significant reductions in ventricular repolarization parameters were observed only in patients with CVD.

Association between Severity of Diabetic Retinopathy and Cardiac Function in Patients with Type 2 Diabetes

Background

The purpose of this research was to assess the relationship between the severity of diabetic retinopathy (DR) and indexes of left ventricle (LV) structure and function in type 2 diabetes mellitus (T2DM).

Methods

Retrospective analysis of 790 patients with T2DM and preserved LV ejection fraction. Retinopathy stages were classified as no DR, early nonproliferative DR, moderate to severe nonproliferative DR, or proliferative DR. The electrocardiogram was used to assess myocardial conduction function. Echocardiography was used to evaluate myocardial structure and function.

Results

Patients were divided into three groups based on the DR status: no DR group (NDR, n = 475), nonproliferative DR group (NPDR, n = 247), and proliferative DR group (PDR, n = 68). LV interventricular septal thickness (IVST) increased significantly with more severe retinopathy (NDR: 10.00 ± 1.09; NPDR: 10.42 ± 1.21; and PDR: 10.66 ± 1.58; P < 0.001). Multivariate logistic regression analysis showed that the significant correlation of IVST persisted between subjects with no retinopathy and proliferative DR (odds ratio = 1.35, P = 0.026). Indices of myocardial conduction function were assessed by electrocardiogram differences among groups of retinopathy (all P < 0.001). In multiple-adjusted linear regression analyses, the increasing degree of retinopathy was closely correlated with heart rate (β = 1.593, P = 0.027), PR interval (β = 4.666, P = 0.001), and QTc interval (β = 8.807, P = 0.005).

Conclusion

The proliferative DR was independently associated with worse cardiac structure and function by echocardiography. Furthermore, the severity of retinopathy significantly correlated with abnormalities of the electrocardiogram in patients with T2DM.

Characteristics of sudden death by clinical criteria

Sudden death is a leading cause of deaths nationally. Definitions of sudden death vary greatly, resulting in imprecise estimates of its frequency and incomplete knowledge of its risk factors. The degree to which time-based and coronary artery disease (CAD) criteria impacts estimates of sudden death frequency and risk factors is unknown. Here, we apply these criteria to a registry of all-cause sudden death to assess its impact on sudden death frequency and risk factors. The sudden unexpected death in North Carolina (SUDDEN) project is a registry of out of-hospital, adjudicated, sudden unexpected deaths attended by Emergency Medical Services. Deaths were not excluded by time since last seen or alive or by prior symptoms or diagnosis of CAD. Common criteria for sudden death based on time since last seen alive (both 24 hours and 1 hour) and prior diagnosis of CAD were applied to the SUDDEN case registry. The proportion of cases satisfying each of the 4 criteria was calculated. Characteristics of victims within each restrictive set of criteria were measured and compared to the SUDDEN registry. There were 296 qualifying sudden deaths. Application of 24 hour and 1 hour timing criteria compared to no timing criteria reduced cases by 25.0% and 69.6%, respectively. Addition of CAD criteria to each timing criterion further reduced qualifying cases, for a total reduction of 81.8% and 90.5%, respectively. However, characteristics among victims meeting restrictive criteria remained similar to the unrestricted population. Timing and CAD criteria dramatically reduces estimates of the number of sudden deaths without significantly impacting victim characteristics.

Survival after multiple episodes of cardiac arrest

BACKGROUND

Cardiopulmonary resuscitation (CPR) is widely used in response to cardiac arrest. However, little is known regarding outcomes for those who undergo multiple episodes of cardiac arrest while in the hospital.

OBJECTIVES

The purpose of this study was to evaluate the association of multiple cardiac events with in-hospital mortality for patients admitted to our tertiary care hospital who underwent multiple code events.

METHODS

We performed a retrospective cohort study on all patients who underwent cardiac arrest from 2012 to 2016. Primary outcome was survival to discharge. Secondary outcomes included post-cardiac-arrest neurologic events (PCANE), non-home discharge, and one-year mortality.

RESULTS

There were 622 patients with an overall mortality rate of 78.0%. Patients undergoing CPR for cardiac arrest once during their admission had lower in-hospital mortality rates compared to those that had multiple (68.9% versus 91.3%, p<.01). Subset analysis of those who had multiple episodes of CPR revealed that more than one event within a 24-hour period led to significantly higher in-hospital mortality rates (94.7% versus 74.4%, p<.01). Other variables associated with in-hospital mortality included body mass index, female sex, malignancy, and increased down time per code. Patients that had a non-home discharge were more likely to have sustained a PCANE than those that were discharged home (31.4% versus 3.9%, p<.01). A non-home discharge was associated with higher one-year mortality rates compared to a home discharge (78.4% versus 54.3%, p=.01).

CONCLUSION

Multiple codes within a 24-hour period and the average time per code were associated with in-hospital mortality in cardiac arrest patients.

Type 2 diabetes mellitus and higher rate of complete atrioventricular block: a Danish Nationwide Registry

AIMS

The present study aimed to determine the association between Type 2 diabetes mellitus (T2DM) and third-degree (complete) atrioventricular block.

METHODS AND RESULTS

This nationwide nested case-control study included patients older than 18 years, diagnosed with third-degree atrioventricular block between 1 July 1995 and 31 December 2018. Data on medication, comorbidity, and outcomes were collected from Danish registries. Five controls, from the risk set of each case of third-degree atrioventricular block, were matched on age and sex to fit a Cox regression model with time-dependent exposure and time-dependent covariates. Subgroup analysis was conducted with Cox regression models for each subgroup. We located 25 995 cases with third-degree atrioventricular block that were matched with 130 004 controls. The mean age was 76 years and 62% were male. Cases had more T2DM (21% vs. 11%), hypertension (69% vs. 50%), atrial fibrillation (25% vs. 10%), heart failure (20% vs. 6.3%), and myocardial infarction (19% vs. 9.2%), compared with the control group. In Cox regression analysis, adjusting for comorbidities and atrioventricular nodal blocking agents, T2DM was significantly associated with third-degree atrioventricular block (hazard ratio: 1.63, 95% confidence interval: 1.57-1.69). The association remained in several subgroup analyses of diseases also suspected to be associated with third-degree atrioventricular block. There was a significant interaction with comorbidities of interest including hypertension, atrial fibrillation, heart failure, and myocardial infarction.

CONCLUSION

In this nationwide study, T2DM was associated with a higher rate of third-degree atrioventricular block compared with matched controls. The association remained independent of atrioventricular nodal blocking agents and other comorbidities known to be associated with third-degree atrioventricular block.

Risk factors of sudden cardiac death in women: A 10 years study in Tunisia

BACKGROUND

Sudden cardiac death (SCD) represents a frequent etiology of sudden death. It represents a major public health issue. Few data about SCD in women are available from the Arab world. Our work aimed to analyze the risk factors of sudden cardiac death in Tunisian women in comparison with men.

METHODS

A cross-sectional retrospective study including all sudden cardiac death cases, conducted in the Forensic Medicine Department of the main teaching hospital of Tunis, between January 2010 and December 2019.

RESULTS

We counted 417 cases of sudden cardiac death in women representing 17.5% of the total number of sudden cardiac deaths recorded during the study period. The average age was 60.03 ± 15.01 years with a predominance of urban married women. The most frequent cardiac risk factors were high blood pressure (50%), diabetes (36.2%), and cardiac disease history (34.2%). Predominately married women with a history of High blood pressure and diabetes, had a high predictive of sudden cardiac death.

CONCLUSION

Cardiac sudden death is no longer a male focused issue. As a matter of facts Rates of SCD in women are rising with a different pattern. We will highlight the importance of adopting specific preventive measures of SCD in female.

Long-term increase in fasting blood glucose is associated with increased risk of sudden cardiac arrest

BACKGROUND

Diabetes mellitus (DM) is associated with various cardiovascular complications, including sudden cardiac arrest (SCA). Furthermore, the severity of DM, as assessed by fasting blood glucose (FBG), is associated with the risk of SCA. However, whether long-term changes in FBG influence on SCA risk remains to be determined.

METHODS

This study used sequential nationwide health screening data from 2009 and 2011. FBG was measured at each health screening, and ΔFBG was calculated as FBG in 2011-FBG in 2009.

RESULTS

Overall, 2,801,153 people were analyzed, and the mean follow-up duration was 6.33 years. Compared with the euglycemic group (- 20 ≤ ΔFBG < 20), the 20 ≤ ΔFBG < 40, 40 ≤ ΔFBG < 100, and ΔFBG ≥ 100 groups had increased SCA risks of 25% (adjusted hazard ratio [HR] = 1.25; 95% confidence interval [CI] 1.16-1.35; p < 0.001), 66% (adjusted HR = 1.66; 95% CI 1.49-1.86; p < 0.001), and 2.9-fold (adjusted HR = 2.85; 95% CI 2.37-3.44; p < 0.001), respectively. The association between ΔFBG and SCA was maintained in people with DM but not in people without DM. However, sex, age, blood pressure, and presence of heart failure did not affect the association between ΔFBG and SCA. A decrease in ΔFBG over time was not associated with reduced risk of SCA: the adjusted HR was 1.11 (95% CI 0.98-1.27; p = 0.113) for the ΔFBG < -40 group and 1.12 (95% CI 1.03-1.22; p = 0.009) for the - 40 ≤ ∆FBG < - 20 group.

CONCLUSIONS

A long-term increase in ΔFBG can be associated with increased risk of SCA in people with DM. However, a long-term decrease in ΔFBG was not associated with reduced risk of SCA. Actions to prevent increase in FBG can have significant effects on public health in terms of SCA prevention.

Association between low-density lipoprotein cholesterol and sudden cardiac arrest in people with diabetes mellitus

BACKGROUND

Dyslipidemia measured as low-density lipoprotein (LDL)-cholesterol is an established risk factor of cardiovascular disease, which is more pronounced in diabetes population. Less is known about the association of LDL-cholesterol level and sudden cardiac arrest (SCA) risk in diabetes mellitus patients. This study investigated the association of LDL-cholesterol level and SCA risk in diabetes population.

METHODS

This study was based on Korean National Health Insurance Service database. Patients who received general examination from 2009 to 2012 and diagnosed as type 2 diabetes mellitus were analyzed. Primary outcome was defined as SCA event identified with International Classification of Disease code.

RESULTS

A total of 2,602,577 patients were included, with total follow-up duration of 17,851,797 person * year. Mean follow-up duration was 6.86 years, and 26,341 SCA cases were identified. Overall incidence of SCA was highest in the lowest LDL-cholesterol group (< 70 mg/dL) and decreased in a linear manner as LDL-cholesterol rises, till 160 mg/dL. Adjustment of covariates resulted in U-shape association, with highest risk of SCA in the highest LDL-cholesterol group (≥ 160 mg/dL) followed by lowest LDL-cholesterol group (< 70 mg/dL). In subgroup analysis, U-shape association between SCA risk and LDL-cholesterol was more pronounced in male, non-obese people, and those who did not use statins.

CONCLUSIONS

In people with diabetes, the association between SCA and LDL-cholesterol level was U-shaped with highest and lowest LDL-cholesterol group having higher risk of SCA than others. Low LDL-cholesterol level can be a surrogate marker for increased risk of SCA in people with diabetes mellitus and this paradoxical association should be recognized and extended to clinical preventive measures.

Being Underweight Is Associated with Increased Risk of Sudden Cardiac Death in People with Diabetes Mellitus

BACKGROUND

Diabetes mellitus (DM) can cause various atherosclerotic cardiovascular disease including sudden cardiac death (SCD). The impact of being underweight on the risk of SCD in people with DM remains to be revealed. We aimed to evaluate the risk of SCD according to body-mass index (BMI; kg/m²) level in DM population.

METHODS

We used a nationwide healthcare insurance database to conduct this study. We identified people with DM among those who underwent nationwide health screening during 2009 to 2012. Medical follow-up data was available until December 2018.

RESULTS

A total of 2,602,577 people with DM with a 17,851,797 person*year follow-up were analyzed. The underweight group (BMI < 18.5) showed 2.4-fold increased risk of SCD during follow-up (adjusted-hazard ratio [HR] = 2.40; 95% confidence interval [CI] = 2.26-2.56; p < 0.001). When normal-BMI group (18.5 ≤ BMI < 23) was set as a reference, underweight group (adjusted-HR = 2.01; 95% CI = 1.88-2.14) showed even higher risk of SCD compared with the obesity group (BMI ≥ 30; adjusted-HR = 0.89; 95% CI = 0.84-0.94). When BMI was stratified by one unit, BMI and SCD risk showed a U-curve association with the highest risk observed at low BMI levels. The lowest risk was observed in 27 ≤ BMI < 28 group. The association between being underweight and increased SCD risk in DM people was maintained throughout various subgroups.

CONCLUSIONS

Being underweight is significantly associated with an increased risk of SCD in the DM population. A steep rise in the risk of SCD was observed as the BMI level decreased below 23. The lowest risk of SCD was observed in 27 ≤ BMI < 28 group.

Diagnosis of coronary artery disease in patients with type 2 diabetes mellitus based on computed tomography and pericoronary adipose tissue radiomics: a retrospective cross-sectional study

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) are highly susceptible to cardiovascular disease, and coronary artery disease (CAD) is their leading cause of death. We aimed to assess whether computed tomography (CT) based imaging parameters and radiomic features of pericoronary adipose tissue (PCAT) can improve the diagnostic efficacy of whether patients with T2DM have developed CAD.

METHODS

We retrospectively recruited 229 patients with T2DM but no CAD history (146 were diagnosed with CAD at this visit and 83 were not). We collected clinical information and extracted imaging manifestations from CT images and 93 radiomic features of PCAT from all patients. All patients were randomly divided into training and test groups at a ratio of 7:3. Four models were constructed, encapsulating clinical factors (Model 1), clinical factors and imaging indices (Model 2), clinical factors and Radscore (Model 3), and all together (Model 4), to identify patients with CAD. Receiver operating characteristic curves and decision curve analysis were plotted to evaluate the model performance and pairwise model comparisons were performed via the DeLong test to demonstrate the additive value of different factors.

RESULTS

In the test set, the areas under the curve (AUCs) of Model 2 and Model 4 were 0.930 and 0.929, respectively, with higher recognition effectiveness compared to the other two models (each p < 0.001). Of these models, Model 2 had higher diagnostic efficacy for CAD than Model 1 (p < 0.001, 95% CI [0.129-0.350]). However, Model 4 did not improve the effectiveness of the identification of CAD compared to Model 2 (p = 0.776); similarly, the AUC did not significantly differ between Model 3 (AUC = 0.693) and Model 1 (AUC = 0.691, p = 0.382). Overall, Model 2 was rated better for the diagnosis of CAD in patients with T2DM.

CONCLUSIONS

A comprehensive diagnostic model combining patient clinical risk factors with CT-based imaging parameters has superior efficacy in diagnosing the occurrence of CAD in patients with T2DM.

Relationship Between Index of Cardiac Electrophysiological Balance, Frontal QRS-T Angle and Retinopathy in People with Type 2 Diabetes

BACKGROUND

Diabetic retinopathy (DR) is strongly associated with cardiovascular disease, which is a risk factor for sudden cardiac death (SCD). The index of cardiac electrophysiological balance (iCEB) and the frontal QRS-T angle are recommended to predict the risk of ventricular arrhythmias more than other ECG parameters. However, the relationships between these two markers and DR have not yet been explored. The aim of this study was to investigate the variation in the iCEB, corrected iCEB (iCEBc) and frontal QRS-T angle in different stages of DR and determine whether there are associations between these markers and DR.

METHODS

The sample comprised 665 patients with Type 2 diabetes mellitus (T2DM) who were classified into three groups: no DR (NDR), mild to moderate non-proliferative DR (NPDR), and vision-threatening DR (VTDR). Twelve-lead ECG was performed and the QT, QTc, QRS duration, iCEB, iCEBc and frontal QRS-T angle were recorded and compared across the groups.

RESULTS

The VTDR group had a significantly higher iCEBc and frontal QRS-T angle than the NDR and NPDR groups. After controlling for confounding variables, the correlations between the iCEBc (OR=2.217, 95% CI=1.464-3.358, P<0.001), frontal QRS-T angle (OR=1.017, 95% CI=1.008-1.025, P<0.001) and DR risk remained (P<0.05). Subjects in the fourth iCEBc quartile (adjusted OR=2.612, 95% CI=1.411-4.834, p=0.002) had a much higher chance of developing DR compared to those in the first quartile. In comparison to the first frontal QRS-T angle quartile, subjects in the third (adjusted OR=1.998, 95% CI=1.167-3.422, P=0.012) and fourth (adjusted OR=2.430, 95% CI=1.420-4.160, P=0.001) frontal QRS-T angle quartiles had significantly greater risks of DR.

CONCLUSION

With the progression of DR, the iCEBc and frontal QRS-T angle increase. An increased iCEBc and frontal QRS-T angle are associated with an increased risk of DR.

Sudden Cardiac Death in Patients With Type 1 Versus Type 2 Diabetes

OBJECTIVE

To investigate the association between type 1 diabetes mellitus (T1D) and type 2 diabetes mellitus (T2D) with risk of sudden cardiac arrest (SCA).

METHODS

In a prospective community-based study of SCA from February 1, 2002, through November 30, 2019, we ascertained 2771 cases age 18 years of age or older and matched them to 8313 controls based on geography, age, sex, and race/ethnicity. We used logistic regression to evaluate the independent association between diabetes, T1D, T2D, and SCA.

RESULTS

Patients had a mean age of 64.5±15.9 years, were 33.3% female and 23.9% non-White race. Overall, 36.7% (n=1016) of cases and 23.8% (n=1981) of controls had diabetes. Among individuals with diabetes, the proportion of T1D was 6.5% (n=66) among cases and 2.0% among controls (n=40). Diabetes was associated with 1.5-times higher odds of SCA. Compared with those without diabetes, the odds ratio and 95% CI for SCA was 4.36 (95% CI, 2.81 to 6.75; P<.001) in T1D and 1.45 (95% CI, 1.30 to 1.63; P<.001) in T2D after multivariable adjustment. Among those with diabetes, the odds of having SCA were 2.41 times higher in T1D than in T2D (95% CI, 1.53 to 3.80; P<.001). Cases of SCA with T1D were more likely to have an unwitnessed arrest, less likely to receive resuscitation, and less likely to survive compared with those with T2D.

CONCLUSION

Type 1 diabetes was more strongly associated with SCA compared with T2D and had less favorable outcomes following resuscitation. Diabetes type could influence the approach to risk stratification and prevention of SCA.

Low Levels of Vitamin D and Silent Myocardial Ischemia in Type 2 Diabetes: Clinical Correlations and Prognostic Significance

Vitamin D deficiency has a pathogenetic and prognostic role in coronary artery disease and a key role in pain transmission. Diabetic patients have a higher risk of silent myocardial ischemia (SMI) due to diabetic neuropathy. We evaluated the correlation between SMI and Vitamin D serum levels in type 2 diabetic patients and assessed whether SMI patients had a worse survival rate than their symptomatic counterpart. We enrolled 253 patients admitted in our Cardiology Unit and compared them with 50 healthy volunteers. We created three sub-groups: symptomatic MI group (125, 32.4%); SMI group (78, 25.7%), and no-MI group (50, 41.9%). 25(OH)D levels (nmol/L) were lower in the SMI group (34.9 ± 5.8) compared to those in the symptomatic MI (49.6 ± 6.1; p = 0.01), no MI (53.1 ± 6.2; p = 0.001), and control groups (62.1 ± 6.7; p = 0.0001). 25(OH)D levels predicted SMI in diabetic patients, with an inverted odds ratio of 1.11 (p = 0.01). Symptomatic MI group survival was higher than the SMI one (6-year survival rate: 83 vs. 69%; p = 0.01). Diabetic patients with SMI had a higher mortality risk and showed lower 25(OH)D levels than the symptomatic group. This suggests the crucial role that vitamin D has in the pathogenesis of SMI.

Excess out-of-hospital cardiac arrests due to ambient temperatures in South Korea from 2008 to 2018

Out-of-hospital cardiac arrest (OHCA) is a notable public health issue with negative outcomes, such as high mortality and aftereffects. Additionally, the adverse effects of extreme temperatures on health have become more important under climate change; however, few studies have investigated the relationship between temperature and OHCA. In this study, we examined the association between temperature and OHCA and its underlying risk factors. We conducted a two-stage time-series analysis using a Poisson regression model with a distributed lag non-linear model (DLNM) and meta-analysis, based on a nationwide dataset from South Korea (2008-2018). We found that 17.4% of excess OHCA was attributed to cold, while 0.9% was attributed to heat. Based on central estimates, excess OHCA attributed to cold were more prominent in the population with hypertension comorbidity (31.0%) than the populations with diabetes (24.3%) and heart disease (17.4%). Excess OHCA attributed to heat were larger in the populations with diabetes (2.7%) and heart disease comorbidity (2.7%) than the population with hypertension (1.2%) based on central estimates. Furthermore, the time-varying excess OHCA attributed to cold have decreased over time, and although those of heat did not show a certain pattern during the study period, there was a weak increasing tendency since 2011. In conclusion, we found that OHCAs were associated with temperature, and cold temperatures showed a greater impact than that of hot temperatures. The effects of cold and hot temperatures on OHCA were more evident in the populations with hypertension, diabetes, and heart diseases, compared to the general population. In addition, the impacts of heat on OHCA increased in recent years, while those of cold temperatures decreased. Our results provide scientific evidence for policymakers to mitigate the OHCA burden attributed to temperature.

Chronically elevated branched chain amino acid levels are pro-arrhythmic

AIMS

Cardiac arrhythmias comprise a major health and economic burden and are associated with significant morbidity and mortality, including cardiac failure, stroke, and sudden cardiac death (SCD). Development of efficient preventive and therapeutic strategies is hampered by incomplete knowledge of disease mechanisms and pathways. Our aim is to identify novel mechanisms underlying cardiac arrhythmia and SCD using an unbiased approach.

METHODS AND RESULTS

We employed a phenotype-driven N-ethyl-N-nitrosourea mutagenesis screen and identified a mouse line with a high incidence of sudden death at young age (6-9 weeks) in the absence of prior symptoms. Affected mice were found to be homozygous for the nonsense mutation Bcat2p.Q300*/p.Q300* in the Bcat2 gene encoding branched chain amino acid transaminase 2. At the age of 4-5 weeks, Bcat2p.Q300*/p.Q300* mice displayed drastic increase of plasma levels of branch chain amino acids (BCAAs-leucine, isoleucine, valine) due to the incomplete catabolism of BCAAs, in addition to inducible arrhythmias ex vivo as well as cardiac conduction and repolarization disturbances. In line with these findings, plasma BCAA levels were positively correlated to electrocardiogram indices of conduction and repolarization in the German community-based KORA F4 Study. Isolated cardiomyocytes from Bcat2p.Q300*/p.Q300* mice revealed action potential (AP) prolongation, pro-arrhythmic events (early and late afterdepolarizations, triggered APs), and dysregulated calcium homeostasis. Incubation of human pluripotent stem cell-derived cardiomyocytes with elevated concentration of BCAAs induced similar calcium dysregulation and pro-arrhythmic events which were prevented by rapamycin, demonstrating the crucial involvement of mTOR pathway activation.

CONCLUSIONS

Our findings identify for the first time a causative link between elevated BCAAs and arrhythmia, which has implications for arrhythmogenesis in conditions associated with BCAA metabolism dysregulation such as diabetes, metabolic syndrome, and heart failure.

Does age influence out-of-hospital cardiac arrest incidence and outcomes among women? Insights from the Paris SDEC

AIMS

Age and sex disparities in out-of-hospital cardiac arrest (OHCA) have been described. Reproductive age may have a protected effect on females vs. males, although results are conflicting. We aimed to clarify this using the Paris Sudden Death Expertise Centre (SDEC) registry.

METHODS AND RESULTS

The Paris SDEC registry collects OHCAs occurring in the Greater Paris Area. We included all OHCAs of presumed cardiac causes occurring between 2013 and 2018. Patients were divided into age groups: 1-13, 13-50, 50-75, and >75 years. Sex and age disparities in OHCA incidence and outcomes were analysed using multivariable negative binomial and logistic regression models. There were 19 782 OHCAs meeting inclusion criteria: 0.37% aged 1-13 years, 12.4% aged 13-50 years, 40.4% aged 50-75 years, and 46.9% aged >75 years. Adjusted incidence rate ratios (IRRs) in females vs. males were for the youngest to the older age groups: 1.29 [95% confidence interval (CI) 0.78-2.13], 0.54 [0.49-0.59], 0.60 [0.56-0.64], and 0.75 [0.67-0.84]. At reproductive age, females were more likely than males to have a return of spontaneous circulation [adjusted odds ratio (OR) 1.60 (1.27-2.02)], to be alive at hospital admission [OR: 1.49 (1.18-1.89)]. In both sexes, patients aged 13-50 years were more likely to survive at hospital discharge than those aged 50-75 years [males: OR 1.81 (1.49-2.20), females: 2.24 (1.54-3.25)]. However, at reproductive age, no sex disparity was observed in survival at hospital discharge [OR: 1.16 (0.75-1.80)].

CONCLUSION

Incidence rate ratios were similar between pre- and post-menopausal aged patients. At reproductive age, no sex disparity in survival at hospital discharge was observed, suggesting that menopausal status may not influence OHCA occurrence and prognosis.

Novel Copper-Zinc-Manganese Ternary Metal Oxide Nanocomposite as Heterogeneous Catalyst for Glucose Sensor and Antibacterial Activity

A novel copper-zinc-manganese trimetal oxide nanocomposite was synthesized by the simple co-precipitation method for sensing glucose and methylene blue degradation. The absorption maximum was found by ultraviolet–visible spectroscopy (UV-Vis) analysis, and the bandgap was 4.32 eV. The formation of a bond between metal and oxygen was confirmed by Fourier Transform Infrared Spectroscopy (FT-IR) analysis. The average crystallite size was calculated as 17.31 nm by X-ray powder diffraction (XRD) analysis. The morphology was observed as spherical by scanning electron microscope (SEM) and high-resolution transmission electron microscopy (HR-TEM) analysis. The elemental composition was determined by Energy Dispersive X-ray Analysis (EDAX) analysis. The oxidation state of the metals present in the nanocomposites was confirmed by the X-ray photoelectron spectroscopy (XPS) analysis. The hydrodynamic diameter and zeta potential of the nanocomposite were 218 nm and −46.8 eV, respectively. The thermal stability of the nanocomposite was analyzed by thermogravimetry-differential scanning calorimetry (TG-DSC) analysis. The synthesized nanocomposite was evaluated for the electrochemical glucose sensor. The nanocomposite shows 87.47% of degradation ability against methylene blue dye at a 50 µM concentration. The trimetal oxide nanocomposite shows potent activity against Escherichia coli. In addition to that, the prepared nanocomposite shows strong antioxidant application where scavenging activity was observed to be 76.58 ± 0.30, 76.89 ± 0.44, 81.41 ± 30, 82.58 ± 0.32, and 84.36 ± 0.09 % at 31, 62, 125, 250, and 500 µg/mL, respectively. The results confirm the antioxidant potency of nanoparticles (NPs) was concentration dependent.

Examination of New Electrocardiographic Repolarization Markers in Diabetic Patients with Noncritical Coronary Artery Disease

Background

Diabetes mellitus (DM) is a multisystemic, chronic disease that affects many organs. Coronary artery disease (CAD) is the leading cause of death in patients with DM. The electrocardiogram's new ventricular repolarization parameters can predict mortality and morbidity. The ventricular repolarization indices were examined in diabetic patients with a CAD diagnosis in this study.

Methods

The study group consisted of 84 DM patients (51 males; mean age 58.8 ± 6.6) with noncritical CAD. The control group consisted of 84 DM patients (47 males; mean age 58.7 ± 8.8) with a normal coronary artery. The intervals of QT, QRS, JT, and Tp-e were all measured. Tp-e/QT, Tp-e/QTc, Tp-e/JT, and Tp-e/JTc ratios were determined with QTc, QTd, QTdc, and JTc intervals.

Results

Heart rate (74.4 ± 13.1 vs. 70.0 ± 13.6 bpm, p: 0.036), QT (381.0 ± 30.3 vs. 368.6 ± 29.1 ms, p: 0.008), QTc (407.5 (359-450) vs. 389 (339-430) ms, p < 0.001), QTd (25.1 ± 6.2 vs. 21.9 ± 9.9 ms, p: 0.013), QTdc (26.7 ± 6.1 vs. 23.1 ± 10.8 ms, p: 0.010), Tp-e (95.7 ± 12.2 vs. 73.6 ± 9.8 ms, p < 0.001), JT (293.8 ± 22.0 vs. 283.5 ± 30.9 ms, p: 0.014), and JTc (313.6 ± 12.3 vs. 302.4 ± 33.7 ms, p=0.005) intervals, and Tp-e/QT (0.25 ± 0.03 vs. 0.20 ± 0.03 ms, p < 0.001), Tp-e/QTc [0.23 (0.19-2.33) vs. 0.19 (0.14-0.25) ms, p=0.007], Tp-e/JT (0.33 ± 0.04 vs. 0.26 ± 0.04 ms, p < 0.001), and Tp-e/JTc (0.30 ± 0.03 vs. 0.24 ± 0.03 ms, p < 0.001) ratios were all found to be significantly higher in diabetic patients with noncritical CAD.

Conclusion

In this study, ventricular repolarization markers on the surface ECG were found to be elevated in diabetic CAD patients. These variables may be related to fatal arrhythmic events. To be sure, large-scale, randomized controlled trials are required.

Identification of Risk Factors for Coronary Artery Disease in Asymptomatic Patients with Type 2 Diabetes Mellitus

BACKGROUND

Patients with diabetes mellitus (DM) are a high-risk group for coronary artery disease (CAD). In the present study, we investigated predictive factors to identify patients at high risk of CAD among asymptomatic patients with type 2 DM based on coronary computed tomographic angiography (CCTA) findings.

METHODS

A single-center prospective study was performed on 452 consecutive patients with type 2 DM who were provided with a weekly hospital-based diabetes education program between 3 October 2015, and 31 March 2020. A total of 161 consecutive asymptomatic patients (male/female: 111/50, age: 57.3 ± 9.3 years) with type 2 DM without any known CAD underwent CCTA. Based on conventional coronary risk factors and non-invasive examination, i.e., measurement of intima-media thickness, subcutaneous and visceral fat area, a stress electrocardiogram test, and the Agatston score, patients with obstructive CAD, CT-verified high-risk plaques (CT-HRP), and optimal revascularization within 90 days were evaluated.

RESULTS

Current smoking (OR, 4.069; 95% C.I., 1.578-10.493, p = 0.0037) and the Agatston score ≥100 (OR, 18.034; 95% C.I., 6.337-51.324, p = 0.0001) were independent predictive factors for obstructive CAD, while current smoking (OR, 5.013; 95% C.I., 1.683-14.931, p = 0.0038) was an independent predictive factor for CT-HRP. Furthermore, insulin treatment (OR, 5.677; 95% C.I., 1.223-26.349, p = 0.0266) was the only predictive factor that correlated with optimal revascularization within 90 days.

CONCLUSIONS

In asymptomatic patients with type 2 DM, current smoking, an Agatston score ≥100, and insulin treatment were independent predictive factors of patients being at high-risk for CAD. However, non-invasive examinations except for Agatston score were not independent predictors of patients being at high risk of CAD.

The role of metabolic syndrome in sudden cardiac death risk: Recent evidence and future directions

Metabolic syndrome (MetS) is a frequent condition whose deleterious effects on the cardiovascular system are often underestimated. MetS is nowadays considered a real pandemic with an estimated prevalence of 25% in general population. Individuals with MetS are at high risk of sudden cardiac death (SCD) as this condition accounts for 50% of all cardiac deaths in such a population. Of interest, recent studies demonstrated that individuals with MetS show 70% increased risk of SCD even without previous history of coronary heart disease (CHD). However, little is known about the interplay between the two conditions. MetS is a complex disease determined by genetic predisposition, unhealthy lifestyle and ageing with deleterious effects on different organs. MetS components trigger a systemic chronic low-grade pro-inflammatory state, associated with excess of sympathetic activity, cardiac hypertrophy, arrhythmias and atherosclerosis. Thus, MetS has an important burden on the cardiovascular system as demonstrated by both preclinical and clinical evidence. The aim of this review is to summarize recent evidence concerning the association between MetS and SCD, showing possible common aetiological processes, and to indicate prospective for future studies and therapeutic targets.

Knockout of interleukin-17A diminishes ventricular arrhythmia susceptibility in diabetic mice via inhibiting NF-κB-mediated electrical remodeling

Interleukin-17A (IL-17), a potent proinflammatory cytokine, has been shown to participate in cardiac electrical disorders. Diabetes mellitus is an independent risk factor for ventricular arrhythmia. In this study, we investigated the role of IL-17 in ventricular arrhythmia of diabetic mice. Diabetes was induced in both wild-type and IL-17 knockout mice by intraperitoneal injection of streptozotocin (STZ). High-frequency electrical stimuli were delivered into the right ventricle to induce ventricular arrhythmias. We showed that the occurrence rate of ventricular tachycardia was significantly increased in diabetic mice, which was attenuated by IL-17 knockout. We conducted optical mapping on perfused mouse hearts and found that cardiac conduction velocity (CV) was significantly decreased, and action potential duration (APD) was prolonged in diabetic mice, which were mitigated by IL-17 knockout. We performed whole-cell patch clamp recordings from isolated ventricular myocytes, and found that the densities of Ito, INa and ICa,L were reduced, the APDs at 50% and 90% repolarization were increased, and early afterdepolarization (EAD) was markedly increased in diabetic mice. These alterations were alleviated by the knockout of IL-17. Moreover, knockout of IL-17 alleviated the downregulation of Nav1.5 (the pore forming subunit of INa), Cav1.2 (the main component subunit of ICa,L) and KChIP2 (potassium voltage-gated channel interacting protein 2, the regulatory subunit of Ito) in the hearts of diabetic mice. The expression of NF-κB was significantly upregulated in the hearts of diabetic mice, which was suppressed by IL-17 knockout. In neonatal mouse ventricular myocytes, knockdown of NF-κB significantly increased the expression of Nav1.5, Cav1.2 and KChIP2. These results imply that IL-17 may represent a potential target for the development of agents against diabetes-related ventricular arrhythmias.

Diagnostic and therapeutic characteristics of diabetes mellitus and risk of out-of-hospital cardiac arrest

This study aimed to evaluate the risks of diabetes mellitus (DM) on out-of-hospital cardiac arrest (OHCA) and to investigate whether the risks of DM on OHCA varied according to the diagnostic and therapeutic characteristics of diabetes. We conducted a multicenter prospective case–control study in 17 University hospitals in Korea from September 2017 to December 2020. Cases were EMS-treated OHCA patients aged 20 to 79 with a presumed cardiac etiology. Community-based controls were recruited at a 1:2 ratio after matching for age, sex, and urbanization level of residence. A structured questionnaire and laboratory findings were collected from cases and controls. Multivariable conditional logistic regression analyses were conducted to estimate the risk of DM on OHCA by characteristics. A total of 772 OHCA cases and 1544 community-based controls were analyzed. A total of 242 (31.3%) OHCAs and 292 (18.9%) controls were previously diagnosed with DM. The proportions of type I DM (10.7% vs. 2.1%) and insulin therapy (15.3% vs. 6.5%) were higher in OHCAs with DM than in controls with DM. The duration of DM was longer in OHCAs than in controls (median 12 vs. 7 years). DM was associated with an increased risk of OHCA (aOR (95% CI), 2.13 (1.64–2.75)). Compared to the no diabetes group, the risks of OHCA increased in the diabetes patients with type I DM (5.26 (1.72–16.08)) and type II DM group (1.63 (1.18–2.27)), a long duration of DM prevalence (1.04 (1.02–1.06) per 1-year prevalence duration), and a high HbA1c level (1.38 (1.19–1.60) per 1% increase). By treatment modality, the aOR (95% CI) was lowest in the oral hypoglycemic agent (1.47 (1.08–2.01)) and highest in the insulin (6.63 (3.04–14.44)) groups. DM was associated with an increased risk of OHCA, and the risk magnitudes varied according to the diagnostic and therapeutic characteristics.

Sudden cardiac death in diabetes and obesity: mechanisms and therapeutic strategies

Ventricular arrhythmias and sudden cardiac death (SCD) occur most frequently in the setting of coronary artery disease, cardiomyopathy and heart failure, but are also increasingly observed in individuals suffering from diabetes mellitus and obesity. The incidence of these metabolic disorders is rising in Western countries, but adequate prevention and treatment of arrhythmias and SCD in affected patients is limited due to our incomplete knowledge of the underlying disease mechanisms. Here, an overview is presented of the prevalence of electrophysiological disturbances, ventricular arrhythmias and SCD in the clinical setting of diabetes and obesity. Experimental studies are reviewed, which have identified disease pathways and associated modulatory factors, in addition to pro-arrhythmic mechanisms. Key processes are discussed, including mitochondrial dysfunction, oxidative stress, cardiac structural derangements, abnormal cardiac conduction, ion channel dysfunction, prolonged repolarization and dysregulation of intracellular sodium and calcium homeostasis. In addition, the recently identified pro-arrhythmic effects of dysregulated branched chain amino acid metabolism, a common feature in patients with metabolic disorders, are addressed. Finally, current management options are discussed, in addition to the potential development of novel preventive and therapeutic strategies based on recent insight gained from translational studies.

Myocardial Extracellular Volume Fraction and T1 Mapping by Cardiac Magnetic Resonance Compared Between Patients With and Without Type 2 Diabetes, and the Effect of ECV and T2D on Cardiovascular Outcomes

Background: To investigate the difference in myocardial extracellular volume fraction (ECV) by cardiac magnetic resonance (CMR) T1 mapping between patients with and without type 2 diabetes (T2D), and the effect of ECV and T2D on cardiovascular (CV) outcomes. Methods: All patients aged > 18 years with known or suspected coronary artery disease who underwent CMR for assessment of myocardial ischemia or myocardial viability at the Department of Cardiology of the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from September 2017 to December 2018 were screened for inclusion eligibility. Left ventricular ejection fraction (LVEF), late gadolinium enhancement, and T1 mapping were performed. ECV values were derived from myocardial native T1 and contrast-enhanced T1 values that were obtained using modified Look-Locker inversion recovery at the septum of the mid-cavity short-axis map. Demographic data, clinical characteristics, and CV outcomes were collected by retrospective chart review. Composite CV outcomes included CV death, acute coronary syndrome, heart failure hospitalization, or ventricular tachycardia (VT)/ventricular fibrillation. Results: A total of 739 subjects (mean age: 69.5 ± 14.0 years, 49.3% men) were included. Of those, 188 subjects had T2D (25.4%). ECV was significantly higher in T2D than in non-T2D (30.0 ± 5.9% vs. 28.8 ± 4.7%, p = 0.004). During the mean follow-up duration of 26.2 ± 8.5 months, 43 patients (5.8%) had a clinical composite outcome, as follows: three CV death (0.4%), seven acute coronary syndrome (0.9%), 33 heart failure hospitalization (4.5%), and one VT (0.1%). T2D, low LVEF, and high ECV were all identified as independent predictors of CV events. Patients with T2D and high ECV had the highest risk of CV events. Conclusion: Among patients with known or suspected coronary artery disease, patients with T2D had a higher ECV. T2D and high ECV were both found to be independent risk factors for adverse CV outcomes.

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.

Diabetes and Risk of Sudden Death in Coronary Artery Disease Patients Without Severe Systolic Dysfunction

OBJECTIVES

This study sought to determine the absolute and relative associations of diabetes mellitus (DM) and hemoglobin A1c (HbA1c) with sudden and/or arrhythmic death (SAD) versus other modes of death in patients with coronary artery disease (CAD) who do not qualify for implantable cardioverter-defibrillators.

BACKGROUND

Patients with CAD and DM are at elevated risk for SAD; however, it is unclear whether these patients would benefit from implantable cardioverter-defibrillators given competing causes of death and/or whether HbA1c might augment SAD risk stratification.

METHODS

In the PRE-DETERMINE study of 5,764 patients with CAD with left ventricular ejection fraction (LVEF) of >30% to 35%, competing risk analyses were used to compare the absolute and relative risks of SAD versus non-SAD by DM status and HbA1c level and to identify risk factors for SAD among 1,782 patients with DM.

RESULTS

Over a median follow-up of 6.8 years, DM and HbA1c were significantly associated with SAD and non-SAD (P < 0.05 for all comparisons); however, the cumulative incidence of non-SAD (19.2%; 95% CI: 17.3%-21.2%) was almost 4 times higher than SAD (4.8%; 95% CI: 3.8%-5.9%) in DM patients. A similar pattern of absolute risk was observed across categories of HbA1c. In analyses limited to patients with DM, HbA1c was not associated with SAD, whereas low LVEF, atrial fibrillation, and electrocardiogram measurements were associated with higher SAD risk.

CONCLUSIONS

In patients with CAD and LVEF of >30% to 35%, patients with DM and/or elevated HbA1c are at much higher absolute risk of dying from non-SAD than SAD. Clinical risk markers, and not HbA1c, were associated with SAD risk in patients with DM. (PRE-DETERMINE: Biologic Markers and MRI SCD Cohort Study; NCT01114269).

Temporal variation in out-of-hospital cardiac arrest occurrence in individuals with or without diabetes

Objective

Out-of-hospital cardiac arrest (OHCA) occurrence has been shown to exhibit a circadian rhythm, following the circadian rhythm of acute myocardial infarction (AMI) occurrence. Diabetes mellitus (DM) is associated with changes in circadian rhythm. We aimed to compare the temporal variation of OHCA occurrence over the day and week between OHCA patients with DM and those without.

Methods

In two population-based OHCA registries (Amsterdam Resuscitation Studies [ARREST] 2010-2016, n = 4163, and Danish Cardiac Arrest Registry [DANCAR], 2010-2014, n = 12,734), adults (≥18y) with presumed cardiac cause of OHCA and available medical history were included. Single and double cosinor analysis was performed to model circadian variation of OHCA occurrence. Stratified analysis of circadian variation was performed in patients with AMI as immediate cause of OHCA.

Results

DM patients (22.8% in ARREST, 24.2% in DANCAR) were older and more frequently had cardiovascular risk factors or previous cardiovascular disease. Both cohorts showed 24 h-rhythmicity, with significant amplitudes in single and double cosinor functions (P-range < 0.001). In both registries, a morning peak (10:00-11:00) and an evening peak (20:00-21:00) was observed in both DM and non-DM patients. No septadian variation was observed in either DM or non-DM patients (P-range 0.13-84).

Conclusions

In these two population-based OHCA registries, we observed a similar circadian rhythm of OHCA occurrence in DM and non-DM patients.

CaMKII Serine 280 O-GlcNAcylation Links Diabetic Hyperglycemia to Proarrhythmia

[Figure: see text].

High haemoglobin A1c level is a possible risk factor for ventricular fibrillation in sudden cardiac arrest among non-diabetic individuals in the general population

Aims

This study aimed to establish whether higher levels of glycated haemoglobin (HbA1c) are associated with increased sudden cardiac arrest (SCA) risk in non-diabetic individuals.

Methods and results

Case–control study in non-diabetic individuals (HbA1c < 6.5%) in the Netherlands. Cases were SCA patients with electrocardiogram (ECG)-documented ventricular fibrillation (VF, the predominant cause of SCA) and HbA1c measurements immediately after VF, prospectively included in September 2009–December 2012. Controls (up to 10 per case) were age/sex-matched non-SCA individuals, included in July 2006–November 2007. We studied 306 cases (56.4 ± 6.8 years, 79.1% male) and 1722 controls (54.0 ± 6.8 years, 64.8% male). HbA1c levels were higher in cases than in controls (5.8 ± 0.3% vs. 5.4 ± 0.3%, P < 0.001). The proportion of increased HbA1c (≥5.7%) was 63.1% in cases and 19.3% in controls (P < 0.001). Multivariate regression models indicated that increased HbA1c was associated with a > six-fold increased VF risk [adjusted odds ratio (OR_adj) 6.74 (5.00–9.09)] and that 0.1% increase in HbA1c level was associated with 1.4-fold increase in VF risk, independent of concomitant cardiovascular risk factors. Increased VF risk at higher HbA1c is associated with acute myocardial infarction (MI) as cause of VF [OR 1.14 (1.04–1.24)], but the association between HbA1c and VF was similar in non-MI patients [OR 1.32 (1.21–1.44)] and MI patients [OR 1.47 (1.37–1.58)].

Conclusion

Among non-diabetic individuals, risk of VF increased with rising HbA1c levels, independent of concomitant cardiovascular disease. Future studies should establish whether HbA1c level may be used as biomarker to recognize individuals at risk for VF.

European Resuscitation Council Guidelines 2021: Epidemiology of cardiac arrest in Europe

In this section of the European Resuscitation Council Guidelines 2021, key information on the epidemiology and outcome of in and out of hospital cardiac arrest are presented. Key contributions from the European Registry of Cardiac Arrest (EuReCa) collaboration are highlighted. Recommendations are presented to enable health systems to develop registries as a platform for quality improvement and to inform health system planning and responses to cardiac arrest.

Isolated downregulation of HCN2 in ventricles of rats with streptozotocin-induced diabetic cardiomyopathy

BACKGROUND

In spite of disrupted repolarization of diabetic heart, some studies report less tendency of diabetic heart to develop ventricular arrhythmias suggesting effective compensatory mechanism. We hypothesized that myocardial alterations in HCN2 and HCN4 channels occur under hyperglycaemia.

METHODS

Diabetes was induced in rats using a single injection of streptozotocin (STZ; 55 mg/kg body weight, i.p.). Basal ECG was measured. Expression of mRNA for HCN channels, potassium channels and microRNA 1 and 133a were measured in ventricular tissues. Protein expression of HCN2 channel isoform was assessed in five different regions of the heart by western blotting. Differentiated H9c2 cell line was used to examine HCN channels expression under hyperglycaemia in vitro.

RESULTS

Six weeks after STZ administration, heart rate was reduced, QRS complex duration, QT interval and T-wave were prolonged in diabetic rats compared to controls. mRNA and protein expressions of HCN2 decreased exclusively in the ventricles of diabetic rats. HCN2 expression levels in atria of STZ rats and H9c2 cells treated with excess of glucose were not changed. MicroRNA levels were stable in STZ rat hearts. We found significantly decreased mRNA levels of several potassium channels participating in repolarization, namely Kcnd2 (Ito1), Kcnh2 (IKr), Kcnq1 (IKs) and Kcnj11 (IKATP).

CONCLUSIONS

This result together with downregulated HCN2 channels suggest that HCN channels might be an integral part of ventricular electric remodelling and might play a role in cardiac repolarization projected in altered arrhythmogenic profile of diabetic heart.

Discovery of predictors of sudden cardiac arrest in diabetes: rationale and outline of the RESCUED (REcognition of Sudden Cardiac arrest vUlnErability in Diabetes) project

Introduction

Early recognition of individuals with increased risk of sudden cardiac arrest (SCA) remains challenging. SCA research so far has used data from cardiologist care, but missed most SCA victims, since they were only in general practitioner (GP) care prior to SCA. Studying individuals with type 2 diabetes (T2D) in GP care may help solve this problem, as they have increased risk for SCA, and rich clinical datasets, since they regularly visit their GP for check-up measurements. This information can be further enriched with extensive genetic and metabolic information.

Aim

To describe the study protocol of the REcognition of Sudden Cardiac arrest vUlnErability in Diabetes (RESCUED) project, which aims at identifying clinical, genetic and metabolic factors contributing to SCA risk in individuals with T2D, and to develop a prognostic model for the risk of SCA.

Methods

The RESCUED project combines data from dedicated SCA and T2D cohorts, and GP data, from the same region in the Netherlands. Clinical data, genetic data (common and rare variant analysis) and metabolic data (metabolomics) will be analysed (using classical analysis techniques and machine learning methods) and combined into a prognostic model for risk of SCA.

Conclusion

The RESCUED project is designed to increase our ability at early recognition of elevated SCA risk through an innovative strategy of focusing on GP data and a multidimensional methodology including clinical, genetic and metabolic analyses.

Presence of fragmented QRS may be associated with complex ventricular arrhythmias in patients with type-2 diabetes mellitus

BACKGROUND

Ventricular arrhythmias (VAs) are frequent in diabetes mellitus (DM) patients. Myocardial fibrosis is one of the components of diabetic cardiomyopathy secondary to DM. Fragmented QRS (fQRS) on electrocardiography (ECG) has been shown to be a marker of myocardial fibrosis. In this study, we aimed to investigate the association between fQRS and complex VAs in patients with DM.

METHODS

Three hundred and thirty-six consecutive patients who were diagnosed with DM were included in the study. The control group consisted of 275 age- and sex-matched healthy individuals. ECG and transthoracic echocardiography were performed in all the patients. fQRS was defined as additional R' wave or notching/splitting of S wave in two contiguous ECG leads. All the patients underwent 24-h Holter monitoring and VAs were classified using Lown's scoring system. Lown class ≥ 3 VAs were considered as complex VAs.

RESULTS

As compared to the healthy individuals, prevalence of fQRS (37.5% vs. 6.9%, p < .001) and complex VAs (14% vs. 0%, p < .001) were significantly higher in patients with DM. Furthermore, complex VAs (28.4% vs. 6.4%, p < .001) were significantly higher in DM patients with fQRS. In multiple logistic regression analysis, DM duration (OR: 1.510, 95% CI:1.343 to 1.698; p < .001) and presence of fQRS (OR: 3.262, 95% CI: 1.443 to 7.376; p = .004) were independent predictors for complex VAs.

CONCLUSIONS

The presence of fQRS may be associated with complex VAs in patients with DM. Therefore, fQRS may be used as a predictor of complex VAs and the risk of sudden death in patients with DM.