Hospital outcome of acute myocardial infarction in patients with and without diabetes mellitus

Diabetes Mellitus and Cardiovascular Disease: Exploring Epidemiology, Pathophysiology, and Treatment Strategies

Diabetes mellitus (DM) affects 537 million people as of 2021, and is projected to rise to 783 million by 2045. This positions DM as the ninth leading cause of death globally. Among DM patients, cardiovascular disease (CVD) is the primary cause of morbidity and mortality. Notably, the prevalence rates of CVD is alarmingly high among diabetic individuals, particularly in North America and the Caribbean (46.0%), and Southeast Asia (42.5%). The predominant form of CVD among diabetic patients is coronary artery disease (CAD), accounting for 29.4% of cases. The pathophysiology of DM is complex, involving insulin resistance, β-cell dysfunction, and associated cardiovascular complications including diabetic cardiomyopathy (DCM) and cardiovascular autonomic neuropathy (CAN). These conditions exacerbate CVD risks underscoring the importance of managing key risk factors including hypertension, dyslipidemia, obesity, and genetic predisposition. Understanding the genetic networks and molecular processes that link diabetes and cardiovascular disease can lead to new diagnostics and therapeutic interventions. Imeglimin, a novel mitochondrial bioenergetic enhancer, represents a promising medication for diabetes with the potential to address both insulin resistance and secretion difficulties. Effective diabetes management through oral hypoglycemic agents (OHAs) can protect the cardiovascular system. Additionally, certain antihypertensive medications can significantly reduce the risk of diabetes-related CVD. Additionally, lifestyle changes, including diet and exercise are vital in managing diabesity and reducing CVD risks. These interventions, along with emerging therapeutic agents and ongoing clinical trials, offer hope for improved patient outcomes and long-term DM remission. This study highlights the urgent need for management strategies to address the overlapping epidemics of DM and CVD. By elucidating the underlying mechanisms and risk factors, this study aims to guide future perspectives and enhance understanding of the pathogenesis of CVD complications in patients with DM, thereby guiding more effective treatment strategies.

Mortality rate of percutaneous coronary interventions in ST-segment elevation myocardial infarction patients under the public health insurance schemes of Thailand

Background

In Thailand, access to specific pharmaceuticals and medical devices for ST-elevation myocardial infarction (STEMI) patients is restricted within certain healthcare systems, leading to inequalities in the quality of medical care among different healthcare systems. This study aims to compare mortality rates within one year of STEMI patients among the public health insurance schemes of Thailand.

Methodology

This study is a single-center retrospective analysis of patients with STEMI treated with primary percutaneous coronary intervention (pPCI). It involves patients utilizing various state health insurance schemes in Thailand from January 1, 2010, to December 31, 2020. Data collection occurred through the hospital's computerized management system and the registration administration office of the Department of Provincial Administration.

Results

The study involved 1,077 patients, categorized into three groups based on their state health insurance: Universal Health Coverage (UC) (546 patients, 50.7%), Social Security System (SS) (199 patients, 18.5%), and Civil Service Reimbursement (CS) (332 patients, 30.8%). The one-year mortality rates in these groups were 10.57%, 4.21%, and 6.47%, respectively (p = 0.010). In the unadjusted model, the SS group showed a lower risk of one-year mortality [Hazard Ratio (HR) 0.38, 95% CI 0.18-0.80, p = 0.011], and the CS group also demonstrated a lower risk (HR 0.59, 95% CI 0.35-0.99, p = 0.047) compared to the UC group. In the adjusted model, only the CS group significantly reduced the risk of one-year mortality. Other factors that affected one-year mortality were age ≥65 years, prior coronary artery diseases, Killip class 3-4, pre-discharge prescription of angiotensin-converting enzyme inhibitors, occlusion in the left anterior descending artery, multivessel disease, in-hospital atrial fibrillation/flutter and in-hospital pericardial effusion.

Conclusion

Healthcare schemes play a significant role in influencing one-year mortality rates among STEMI patients treated with pPCI. This information would be crucial for developing strategies and programs to aid healthcare policymakers at both regional and international levels in reducing morbidity and mortality.

Prognostic impact of diabetes mellitus on in-hospital mortality in patients with acute myocardial infarction complicating renal dysfunction according to age and sex

BACKGROUND

Patients with acute myocardial infarction (AMI) complicating renal dysfunction (RD) are recognized as being at high risk. Although diabetes mellitus (DM) is a major cause of RD, the prognostic impact of coexisting DM on mortality in patients with AMI complicating RD is ill-defined. This study compared the prognostic impact of coexisting DM in patients with AMI complicating RD according to both age and sex.

METHODS

A multicenter retrospective study was conducted on 2988 consecutive patients with AMI complicating RD (estimated glomerular filtration rate <60 mL/min per 1.73 m2). Multivariable Cox regression analysis was performed to investigate the effects of DM on in-hospital mortality.

RESULTS

Statistically significant interactions between age and DM and between sex and DM for in-hospital mortality were revealed in the entire cohort. Coexisting DM was identified as an independent risk factor for in-hospital mortality (hazard ratio [HR], 2.543) in young (aged <65 years), but not old (aged ≥65 years), patients. DM was identified as an independent risk factor (HR, 1.469) in male, but not female, patients. Kaplan-Meier survival curves showed that DM correlated with significantly low survival rates in patients that were young or male as compared to those who were old or female.

CONCLUSIONS

There were significant differences in the prognostic impact of DM on in-hospital mortality between young and old as well as male and female patients with AMI complicating RD. These results have implications for future research and the management of patients with DM, RD, and AMI comorbidities.

Association between type II diabetes mellitus and 90-day mortality in a large multicenter prospectively collected cohort. A FROG ICU post-hoc study

PURPOSE

Factors associated with adverse outcomes in ICU patients with type II (T2DM) are poorly defined. The main goal of this study is to determine the impact of pre-existing T2DM on 90-day mortality post ICU admission.

MATERIAL

Post-hoc analysis from the FROG-ICU cohort. All patients admitted to ICU who were ventilated and/or treated by a vasoactive agent for >24 h were included. Association between T2DM and 90-day mortality was analyzed in unmatched, and populations matched by propensity score (PS) method to balance confounders recorded before ICU admission. Analysis was performed in non-imputed and imputed datasets.

RESULTS

2002 patients were included, and 16% had a history of T2DM. The latter were at inclusion more severely ill (SAPSII score 51(39-67) vs 48(35-61), p < 0.0001; Charlson score 2(1-3) vs 0(0-2), p < 0.0001). In the unmatched cohort, T2DM patients had a higher 90-day risk of death compared to no-DM patients (HR 1.35(1.1-1.65)). The 90-day risk of death was not significantly different T2DM and no T2DM patients after PS matching (HR: 0.81 (0.56-1.18). Results were similar with the analysis performed on imputed datasets (pooled HR: 0.95 (0.69-1.30)).

CONCLUSIONS

In the present study, T2DM was not associated with 90-day mortality post ICU admission.

Metformin use and cardiovascular outcomes after acute myocardial infarction in patients with type 2 diabetes: a cohort study

Background

The use of metformin after acute myocardial infarction (AMI) has been associated with reduced mortality in people with type 2 diabetes mellitus (T2DM). However, it is not known if it is acutely cardioprotective in patients taking metformin at the time of AMI. We compared patient outcomes according to metformin status at the time of admission for fatal and non-fatal AMI in a large cohort of patients in England.

Methods

This study used linked data from primary care, hospital admissions and death registry from 4.7 million inhabitants in England, as part of the CALIBER resource. The primary endpoint was a composite of acute myocardial infarction requiring hospitalisation, stroke and cardiovascular death. The secondary endpoints were heart failure (HF) hospitalisation and all-cause mortality.

Results

4,030 patients with T2DM and incident AMI recorded between January 1998 and October 2010 were included. At AMI admission, 63.9% of patients were receiving metformin and 36.1% another oral hypoglycaemic drug. Median follow-up was 343 (IQR: 1–1436) days. Adjusted analyses showed an increased hazard of the composite endpoint in metformin users compared to non-users (HR 1.09 [1.01–1.19]), but not of the secondary endpoints. The higher risk of the composite endpoint in metformin users was only observed in people taking metformin at AMI admission, whereas metformin use post-AMI was associated with a reduction in risk of all-cause mortality (0.76 [0.62–0.93], P = 0.009).

Conclusions

Our study suggests that metformin use at the time of first AMI is associated with increased risk of cardiovascular disease and death in patients with T2DM, while its use post-AMI might be beneficial. Further investigation in well-designed randomised controlled trials is indicated, especially in view of emerging evidence of cardioprotection from sodium-glucose co-transporter-2 (SGLT2) inhibitors.

Vascular Inflammation and Oxidative Stress: Major Triggers for Cardiovascular Disease

Cardiovascular disease is a leading cause of death and reduced quality of life, proven by the latest data of the Global Burden of Disease Study, and is only gaining in prevalence worldwide. Clinical trials have identified chronic inflammatory disorders as cardiovascular risks, and recent research has revealed a contribution by various inflammatory cells to vascular oxidative stress. Atherosclerosis and cardiovascular disease are closely associated with inflammation, probably due to the close interaction of inflammation with oxidative stress. Classical therapies for inflammatory disorders have demonstrated protective effects in various models of cardiovascular disease; especially established drugs with pleiotropic immunomodulatory properties have proven beneficial cardiovascular effects; normalization of oxidative stress seems to be a common feature of these therapies. The close link between inflammation and redox balance was also supported by reports on aggravated inflammatory phenotype in the absence of antioxidant defense proteins (e.g., superoxide dismutases, heme oxygenase-1, and glutathione peroxidases) or overexpression of reactive oxygen species producing enzymes (e.g., NADPH oxidases). The value of immunomodulation for the treatment of cardiovascular disease was recently supported by large-scale clinical trials demonstrating reduced cardiovascular mortality in patients with established atherosclerotic disease when treated by highly specific anti-inflammatory therapies (e.g., using monoclonal antibodies against cytokines). Modern antidiabetic cardiovascular drugs (e.g., SGLT2 inhibitors, DPP-4 inhibitors, and GLP-1 analogs) seem to share these immunomodulatory properties and display potent antioxidant effects, all of which may explain their successful lowering of cardiovascular risk.

Revascularization strategies in patients with Type 2 diabetes mellitus

This review aims to describe new developments in coronary revascularization strategies for patients with pre-existing Type 2 diabetes mellitus (DM). Recommended strategies for revascularization have been an active area of study with recent important developments. In patients with Type 2 DM and multivessel coronary artery disease (CAD), coronary artery bypass graft (CABG) surgery is the preferred method for revascularization. Patients with DM are at increased risk for diffuse cardiovascular disease due to the proinflammatory, prothrombotic effects of chronic hyperglycemia. In patients undergoing percutaneous coronary intervention, drug-eluting stents and more potent antiplatelet agents especially in those presenting with acute coronary syndromes should be employed.

Insulin resistance is associated with coronary plaque vulnerability: insight from optical coherence tomography analysis

AIMS

Previous studies have reported that insulin resistance plays an important role in the progression of atherosclerosis. However, the relationship between insulin resistance and coronary plaque instability is not well established. The purpose of this study was to assess the relationship between insulin resistance and coronary plaque characteristics identified by optical coherence tomography (OCT).

METHODS AND RESULTS

This study enrolled 155 consecutive patients undergoing percutaneous coronary intervention. OCT image acquisitions were performed in the culprit lesions. Insulin resistance was identified using the homeostasis model assessment of insulin resistance (HOMA-IR). Subjects were divided into three tertiles according to the HOMA-IR values. Patients in the higher HOMA tertile had more frequent prevalence of lipid-rich plaques than those in the middle and lower tertiles (83 vs. 62 vs. 57%; P = 0.01). The thin-cap fibroatheroma (TCFA) prevalence rates among the higher (>2.5), middle (1.4-2.5), and lower HOMA-IR (<1.4) tertiles were 50, 29, and 26% (P = 0.02). The microvessel prevalence rates of the three tertiles were 54, 39, and 28% (P = 0.02). Furthermore, in the higher HOMA-IR group, the fibrous cap was significantly thinner compared with the other two tertiles (vs. lower HOMA-IR, P = 0.009; vs. middle HOMA-IR, P = 0.008). On multivariate analysis, acute coronary syndrome [odds ratio (OR): 17.98; 95% confidence interval (CI): 7.12-52.02; P < 0.0001] and HOMA-IR >2.50 (OR: 3.57; 95% CI: 1.42-9.55; P = 0.007) were independent predictors for the presence of TCFA.

CONCLUSION

This study suggests that insulin resistance might be associated with coronary plaque vulnerability.

Comparison of nonculprit coronary plaque characteristics between patients with and without diabetes: a 3-vessel optical coherence tomography study

OBJECTIVES

The aim of the present study was to compare the characteristics of nonculprit coronary plaques between diabetes mellitus (DM) and non-DM patients using 3-vessel optical coherence tomography (OCT) imaging.

BACKGROUND

DM patients have a higher recurrent cardiovascular event rate.

METHODS

Patients who had undergone 3-vessel OCT imaging were identified from the Massachusetts General Hospital OCT Registry. Characteristics of nonculprit plaques were compared between DM and non-DM patients.

RESULTS

A total of 230 nonculprit plaques were identified in 98 patients. Compared with non-DM patients, DM patients had a larger lipid index (LI) (averaged lipid arc × lipid length; 778.6 ± 596.1 vs. 1358.3 ± 939.2, p < 0.001) and higher prevalence of calcification (48.4% vs. 72.2%, p = 0.034) and thrombus (0% vs. 8.3%, p = 0.047). DM patients were divided into 2 groups based on glycated hemoglobin (A(1C)) levels of ≤7.9% and ≥8.0%. LI was significantly correlated with diabetic status (778.6 ± 596.1 [non-DM] vs. 1,171.5 ± 708.1 [A(1C) ≤7.9%] vs. 1,638.5 ± 1,173.8 [A(1C) ≥8%], p value for linear trend = 0.005), and fibrous cap thickness was inversely correlated with the A(1C) level (99.4 ± 46.7 μm [non-DM] vs. 91.7 ± 29.6 μm [A(1C) ≤7.9%] vs. 72.9 ± 22.7 μm [A(1C) ≥8%], p value for linear trend = 0.014). Patients with A(1C) ≥8% also had the highest prevalence of thin-cap fibroatheroma (TCFA) and macrophage infiltration.

CONCLUSIONS

Compared with non-DM patients, DM patients have a larger LI and a higher prevalence of calcification and thrombus. The LI was larger and TCFA and macrophage infiltration were frequent in patients with A(1C) ≥8%.

Prognostic value of admission heart rate in patients with ST-segment elevation myocardial infarction: role of type 2 diabetes mellitus

BACKGROUND

It's unknown whether the prognostic value of admission heart rate (HR) was different in patients with ST-segment elevation myocardial infarction (STEMI) with or without concomitant type 2 diabetes mellitus (T2DM).

METHODS

Consecutive STEMI patients who presented within 12 hours of symptom onset were recruited from 274 hospitals in China. Participants were stratified into quartiles by admission HR. Baseline characteristics, current therapeutic recommenda- tions, laboratory biochemical tests, 30-day all-cause mortality and Cardiovascular Events (CVE, including all-cause death, reinfarction and stroke) were compared across admission HR quartiles.

RESULTS

We evaluated 7294 STEMI patients, of these 820 (11.2%) had known T2DM. The admission HR quartile stratification was significantly associated with all-cause mortality and CVE regardless of T2DM status (P < 0.001 both for survival and CVE). After adjusted other risk factors, in patients without T2DM, comparing with HR <66 b.p.m., the increase of HR level was associated with worse prognosis (P < 0.05). In patients with T2DM, the hazard ratios for 30-day CVE were 1.75 (95%CI), 1.92 (95%CI), 3.00 (95%CI) in the HR of 66-76 b.p.m., 77-88 b.p.m., and >88 b.p.m., respectively. Results were similar for 30-day all-cause mortality, but the hazard ratios in Q2 (P = 0.139 and P =0.086 for survival and CVE, respectively) and Q3 groups were non-significant (P = 0.072 and P =0.033 for survival and CVE, respectively). There was a significant interaction effect of HR and T2DM on 30-day CVE mortality (P = 0.035), which was not found on all-cause mortality (P = 0.126).

CONCLUSION

Admission heart rate was an important risk factor of 30-day all-cause mortality and CVE in patients with STEMI with or without T2DM. However, the predictive effect was modified by T2DM.

Primary and secondary prevention of cardiovascular disease in diabetes with aspirin

Diabetes is associated with an increased cardiovascular risk. The role for aspirin in diabetes is of high clinical interest. Guidelines recommend that primary prevention of cardiovascular disease (CVD) in diabetes with aspirin should be based on the individual risk for CVD. New mechanistic studies suggest that enhanced platelet turnover may partly contribute to the fact the primary prevention studies found unequivocal results in diabetes. There is initial evidence that a potential future modification of dosages in diabetes may counteract the enhancement in platelet turnover in diabetes. The use of aspirin in diabetic patients for secondary prevention of CVD is supported by key evidence. The aim of the review is to present recent studies on aspirin for prevention of CVD in diabetes and to highlight its role also in view of new mechanistic and clinical studies with aspirin. Novel aspects of aspirin, e.g. its potential role for the prevention of cancer, are also presented.

Is there an additional benefit from coronary revascularization in diabetic patients with acute coronary syndromes or stable angina who are already on optimal medical treatment?

Cardiovascular disease (CVD) is common in patients with diabetes mellitus (DM) and related clinical outcomes are worse compared with non-diabetics. The optimal treatment in diabetic patients with coronary heart disease (CHD) is currently not established. We searched MEDLINE (1975-2010) using the key terms diabetes mellitus, coronary heart disease, revascularization, coronary artery bypass, angioplasty, coronary intervention and medical treatment. Most studies comparing different revascularization procedures in patients with CHD favoured coronary artery bypass graft (CABG) surgery in patients with DM. However, most of this evidence comes from subgroup analyses. Recent evidence suggests that advanced percutaneous coronary intervention (PCI) techniques along with best medical treatment may be non-inferior and more cost-effective compared with CABG. Treatment of vascular risk factors is a key option in terms of improving CVD outcomes in diabetic patients with CHD. The choice between medical therapy and revascularization warrants further assessment.

Oral glucose tolerance test and HbA₁c for diagnosis of diabetes in patients undergoing coronary angiography: [corrected] the Silent Diabetes Study

AIMS/HYPOTHESIS

The primary aim of this study was to compare the results of HbA(1c) measurements with those of an OGTT for early diagnosis of 'silent diabetes' in patients with coronary artery disease (CAD) undergoing angiography without prediagnosed diabetes. A secondary aim was to investigate the correlation between the extent of CAD and the glycaemic status of the patient.

METHODS

Data from 1,015 patients admitted for acute (n = 149) or elective (n = 866) coronary angiography were analysed. Patients with known diabetes were excluded from the study. Using the OGTT results, patients were classified as having normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) or diabetes. According to the results of the HbA(1c) measurements, patients were classified into three groups: normal (HbA(1c) <5.7% [<39 mmol/mol]), borderline (HbA(1c) 5.7-6.4% [39-47 mmol/mol]) and diabetes (HbA(1c) ≥6.5% [≥48 mmol/mol]).

RESULTS

Based on the OGTT, 513 patients (51%) were classified with NGT, 10 (1%) with IFG, 349 (34%) with IGT and 149 (14%) were diagnosed with diabetes. According to HbA(1c) measurements, 588 patients (58%) were classified as normal, 385 (38%) as borderline and 42 (4%) were diagnosed with diabetes. The proportion of patients with IGT and diabetes increased with the extent of CAD (IGT ρ = 0.14, p < 0.001, diabetes ρ = 0.09, p = 0.01). No differences in HbA(1c) were seen among the groups with different extents of CAD (p = 0.652).

CONCLUSIONS/INTERPRETATION

An OGTT should be performed routinely for diagnosis of diabetes in patients with CAD undergoing coronary angiography, since HbA(1c) measurement alone appears to miss a substantial proportion of patients with silent diabetes. A limitation of the study is that the OGTT was not performed before the angiography.

Prediabetes: to treat or not to treat?

The incidence of diabetes is continuously increasing worldwide. Pre-diabetes (defined as impaired glucose tolerance, impaired fasting glucose or both) represents an intermediate state, which often progresses to overt diabetes within a few years. In addition, pre-diabetes may be associated with increased risk of microvascular and macrovascular complications. Thus, reverting a pre-diabetic state as well as preventing the development of diabetes represents enormous challenge for the clinician. Lifestyle modification in pre-diabetic individuals was found particularly effective in the prevention of diabetes. However, compliance to lifestyle modification measures can be a crucial problem in the everyday clinical practice, especially in developing countries. During the last decade many studies support the use of anti-diabetic treatment schemes in pre-diabetic subjects to be advantageous. The American Diabetes Prevention Program (DPP) as well as other minor studies and meta-analyses has convincingly demonstrated the efficacy of metformin in this patient group. In addition, results of the 10 year DPP follow up have recently been published, demonstrating the long term safety and sustainability of metformin treatment benefits in this population. In contrast to metformin, the evidence from the use of other anti-diabetic agents (thiazolidinediones, a-glucosidase inhibitors, incretin mimetics) in pre-diabetic individuals is rather inadequate and prospective data is further needed. Furthermore, large scale studies with hard clinical endpoints are needed to delineate the effect of pre-diabetes treatment on macro- and microvascular complications. In conclusion, several strategies of patient management, mainly lifestyle modification and pharmacological interventions can prevent diabetes development in subjects diagnosed with pre-diabetes or even revert pre-diabetic state. However, whether this biochemical improvement can be translated into actual clinical benefit remains to be established.

Increasing resources effected equity in access to revascularizations for patients with diabetes

OBJECTIVES

To examine differences in access to coronary revascularization among a cohort of coronary patients with and without diabetes in 1995-2002 in Finland and to examine how rapidly increasing resources effected socioeconomic equity in access to these operations.

DESIGN

An individual level nationwide register-based study of newly diagnosed CHD (coronary heart disease) patients (aged 40-79) in Finland. Rates for revascularizations were calculated per 1 000 person years. Socioeconomic differences were examined using Cox regression.

RESULTS

Revascularization rates increased from 354 to 443 per 1 000 person years among men with CHD and from 301 to 366 among patients with diabetes. Among women with CHD the numbers were 224 and 249 and among patients with diabetes 208 and 325. Comparing trends for first revascularization between patient groups with and without diabetes differences increased somewhat among men. Among women, revascularization rates increased more among diabetic patients. Lower revascularization rates among lower socioeconomic groups were found throughout the study period in both patient groups.

CONCLUSIONS

Simultaneously with large increase in cardiac operation rates, revascularization observed more common among women with diabetes compared to those without. However socioeconomic inequity in access to revascularizations among both genders remained even after increase in resources.

Blood glucose control and coronary heart disease

Epidemiologic data support the hypothesis of a direct and independent relationship between hyperglycemia and cardiovascular disease. The lack of a clear-cut threshold value in diabetic patients, and the persistence of the relationship in nondiabetic population as well, suggest that glycemia is a continuous variable, similarly to other cardiovascular risk factors. Moreover, increased plasma glucose levels contribute to cardiovascular risk by activating multiple atherogenic mechanisms. In spite of evident plausibility for hyperglycemia as a cardiovascular risk factor per se, intervention data remain controversial. Results of recent large-scale intervention trials, such as ACCORD, ADVANCE, and VADT, seem to undermine the concept that tight glycemic control confers some protection against cardiovascular disease in patients with type 2 diabetes, while maintenance of near-normal glycemic control from earlier stage of the disease and during acute coronary events seems to be more beneficial. However, individualized therapies remain the cornerstone of strategies aimed to reduce cardiovascular risk associated to hyperglycemia.

Relation between aortic knob calcium observed by simple chest x-ray or fluoroscopy and plaque components in patients with diabetes mellitus

We used virtual histology and intravascular ultrasound (VH-IVUS) to evaluate the relation between aortic knob calcium (AKC) and plaque components in diabetic patients. The presence of AKC was assessed by posteroanterior view of chest x-ray or fluoroscopy at the time of coronary angiography. A total of 137 de novo coronary culprit lesions in 137 consecutive diabetic patients were studied and coronary plaque components were analyzed using VH-IVUS according to the presence (n = 45) or absence (n = 92) of AKC. Patients with AKC were significantly older (68 +/- 8 vs 62 +/- 9 years, p <0.001) and had significantly higher high-sensitivity C-reactive protein levels (1.97 +/- 1.33 vs 0.48 +/- 1.35 mg/dl, p = 0.005) compared to patients without AKC. Absolute and percent necrotic core (NC) volumes (30 +/- 26 vs 20 +/- 19 mm(3), p = 0.003; 23.4 +/- 10.3% vs 17.4 +/- 8.9%, p = 0.005, respectively) and absolute and percent dense calcium (DC) volumes (17 +/- 12 vs 11 +/- 12 mm(3), p = 0.010; 13.3 +/- 7.3% vs 9.6 +/- 7.9%, p = 0.011, respectively) were significantly greater in lesions with AKC compared to those without AKC. Multivariable analysis showed that age (odds ratio [OR] 1.233, 95% confidence interval [CI] 1.121 to 1.355, p <0.001), high-sensitivity C-reactive protein (OR 1.871, 95% CI 1.090 to 2.943, p = 0.007), absolute DC volume (OR 1.020, 95% CI 1.050 to 1.178, p = 0.003), and absolute NC volume (OR 1.026, 95% CI 1.057 to 1.199, p <0.001) were independent predictors of AKC. In conclusion, diabetic patients with AKC were older, had greater NC- and DC-containing plaques, and higher inflammatory status compared to diabetic patients without AKC.

The Munich Myocardial Infarction Registry: impact of C-reactive protein and kidney function on hospital mortality in diabetic patients

INTRODUCTION

The aim of this study was to analyse hospital mortality with regards to the presence of diabetes, elevation of C-reactive protein (CRP) levels and impaired kidney function (IKF) on admission.

METHODS

All patients in the Munich Myocardial Infarction Registry (1999-2004, n = 2,015) were assessed. In both the diabetic (n = 770, 38%) and non-diabetic (n = 1,245, 61.2%) groups, CRP and kidney function on admission were analysed with regards to hospital outcome.

RESULTS

In diabetic patients, both a CRP level >7 mg/L and a glomerular filtration rate (GFR) < 60 ml/min were independent risk factors for mortality (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.8-6.9 and OR 4.4, 95% CI 2.4-8.3, respectively). In non-diabetic patients with CRP levels equal or below the median and absence of IKF, hospital mortality was 0.7% whereas the presence of the triad of diabetes, CRP levels above the median and IKF increased hospital mortality to 23.5%.

CONCLUSION

The registry demonstrates that the presence of the triad of diabetes, elevated CRP levels and reduced GFR on admission is associated with an excessive hospital mortality. Optimised early interventions are to be initiated to potentially overcome the unfavourable prognosis.

Effect of blood glucose concentrations on admission in non-diabetic versus diabetic patients with first acute myocardial infarction on short- and long-term mortality (from the MONICA/KORA Augsburg Myocardial Infarction Registry)

The aim of this study was to investigate the association between increased admission glucose in nondiabetic (ND) patients and in patients with type 2 diabetes mellitus (T2DM) with first acute myocardial infarctions (AMIs) and 28-day as well as 1- and 3-year case fatality. The Monitoring Trends and Determinants in Cardiovascular Disease (MONICA)/Cooperative Health Research in the Region of Augsburg (KORA) myocardial infarction registry database in Augsburg, Germany, was used, and 1,631 patients without and 659 patients with T2DM (aged 25 to 74 years) who were admitted from 1998 to 2003 with first AMIs were included. Mortality follow-up was carried out in 2005. ND patients with AMIs with admission glucose >152 mg/dl (top quartile) compared with those in the bottom quartile had an odds ratio of 2.82 (95% confidence interval [CI] 1.30 to 6.12) for death within 28 days after multivariate adjustment; correspondingly, patients with T2DM with admission glucose >278 mg/dl (top quartile) compared with those in the bottom quartile (<152 mg/dl) showed a nonsignificantly increased odds ratio of 1.45 (95% CI 0.64 to 3.31). After the exclusion of patients who died within 28 days, a nonsignificantly increased relative risk (RR) was seen between admission blood glucose and 1-year mortality in ND subjects (RR 2.71, 95% CI 0.90 to 8.15), whereas no increased RR was found in subjects with diabetes (RR 0.99, 95% CI 0.34 to 2.82). After 3 years, there was no increased risk for death in patients with high admission blood glucose levels, neither for ND patients nor for those with T2DM. In conclusion, elevated admission blood glucose is associated with increased short-term mortality risk in patients with AMIs, particularly in ND subjects. These patients constitute a high-risk group needing aggressive, comprehensive polypharmacotherapy.

Plaque characteristics in culprit lesions and inflammatory status in diabetic acute coronary syndrome patients

OBJECTIVES

The aim of this study was to assess the plaque characteristics in culprit lesions in diabetic patients with acute coronary syndrome (ACS).

BACKGROUND

Data of the relationship between diabetes mellitus and plaque characteristics in patients with ACS are lacking.

METHODS

We performed grayscale intravascular ultrasound (IVUS) analysis in 422 ACS patients and virtual histology (VH)-IVUS in 310 ACS patients. By subgroup analysis, 112 patients with acute myocardial infarction (AMI) with plaque ruptures also were evaluated.

RESULTS

In the diabetic subgroup, high-sensitivity C-reactive protein (hs-CRP) was significantly increased (p = 0.008), multivessel disease was more common (65% vs. 29%, p < 0.001), and plaque burden was greater (79.7 +/- 9.8 mm2 vs. 74.2 +/- 8.9 mm2, p < 0.001). In the subgroup analysis of 112 AMI patients with plaque ruptures, the presence of multiple plaque ruptures (60% vs. 29%, p = 0.001) and thrombus (72% vs. 52%, p = 0.032) were more common in diabetic group. Diabetes mellitus was the independent predictor of hs-CRP elevation (odds ratio [OR]: 3.030, 95% confidence interval [CI]: 1.204 to 7.623, p = 0.019), and multiple plaque ruptures (OR: 2.984, 95% CI: 1.311 to 6.792, p = 0.009) by multivariable analysis. In 310 VH-IVUS subsets, the absolute and percent necrotic core volumes were significantly greater (16.9 +/- 15.1 mm3 vs. 11.5 +/- 11.4 mm3, p < 0.001, and 17.3 +/- 9.4% vs. 13.7 +/- 7.5%, p < 0.001, respectively), and the presence of at least one thin-cap fibroatheroma (TCFA) (60% vs. 42%, p = 0.003) and multiple TCFAs (28% vs. 11%, p < 0.001) were more common in the diabetic group. Diabetes mellitus was the only independent predictor of TCFA by multivariable analysis (OR: 2.139, 95% CI: 1.266 to 3.613, p = 0.004).

CONCLUSIONS

Diabetic patients with ACS have more plaques with characteristics of plaque vulnerability, different composition of plaques, and have increased inflammatory status compared with nondiabetic patients with ACS.

The impact of glucose-lowering therapy on cardiovascular outcomes

Despite some controversies, especially in 2008, evidence is mounting by a number of randomised controlled trials in recent years that blood-glucose-lowering therapy (as an integral part of multifactorial therapy) reduces cardiovascular disease (CVD) for longer term, both in type 1 and type 2 diabetes. In particular, cardiovascular events are reduced by approximately 10-15% per 1% absolute reduction of HbA1c, on top of other CVD-risk-reducing therapies. With regard to mortality, the situation is less clear, as those intervention studies need at least a 10-year follow-up. In fact, some risks involved with blood-glucose-lowering therapy, for example, hypoglycaemia and weight gain, especially in patients with prior CVD, may also impact unfavourably on (cardiovascular) mortality. Therefore, blood glucose lowering is a highly individualised therapy with a target for HbA1c <or=7.0% or 6.5%, which takes time to tailor (poly-)pharmacotherapy gently to the patient's needs. Drug-specific effects, both advantageous and disadvantageous, of blood-glucose-lowering therapy cannot be excluded currently and warrant further studies.

Poor outcomes after acute myocardial infarction in systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is associated with higher risk for acute myocardial infarction (MI); but the post-infarction outcomes among these patients are unknown. Our objective was to compare post-acute MI outcomes in patients with SLE to those with diabetes mellitus (DM) and those with neither condition.

METHODS

We analyzed the risk for prolonged hospitalization and in-hospital mortality following acute MI in the 1993-2002 US Nationwide Inpatient Sample. We used logistic regression to calculate odds ratios (OR) for prolonged hospitalization and Cox proportional hazards regression to calculate hazard ratios (HR) for in-hospital mortality with and without adjustments for age, sex, race/ethnicity, socioeconomic status, and presence of congestive heart failure.

RESULTS

For the SLE (n = 2192), DM (n = 236,016), SLE/DM (n = 474), and control (n = 667,956) groups, the in-hospital mortality rates were 8.3%, 6.2%, 5.7%, and 4.7%, respectively. In multivariable regression models, all 3 disease groups had higher adverse outcome risk compared to control. The OR for prolonged hospitalization was higher for those with SLE (OR 1.48, 95% CI 1.32-1.79) compared to those with DM (OR 1.30, 95% CI 1.28-1.32). A similar pattern was observed for hazard ratios for in-hospital mortality as well (SLE, HR 1.65, 95% CI 1.33-2.04; DM, HR 1.11, 95% CI 1.07-1.14).

CONCLUSION

SLE, like DM, increases risk of poor outcomes after acute MI. These patients need to be triaged appropriately for aggressive care.

[Glucose control in cardiac disease]

The early and differentiated optimization of glucose level is essential for the improvement of the cardiovascular outcome. In all stages of cardiac disease, the primary goal is to reach near-normoglycemia. The DIGAMI-1 and 2 studies as well as the Munich Myocardial Infarction Registry successfully demonstrate, that the intensification of treatment with insulin therapy reduces the mortality of myocardial infarction. Glucose-insulin-infusion is advantageous with regard to the use of a well-controllable therapeutic approach. In non-acute cardiac disease, oral treatment strategies and insulin therapy are successful alone or in combination. Acarbose and metformin have been shown to be able to successfully prevent cardiovascular disease. New evidence of positive effects of glitazones with regard to reduction of the rate of restenosis and optimization of endothelial function is currently emerging. Prognosis of cardiovascular disease is significantly influenced by glucose control. There is evidence that the relationship between glycemia and cardiovascular events extends far beyond the diabetic threshold. This can be detected even in impaired glucose tolerance and the non-diabetic range. There is evidence that postprandial glycemia is crucial for the extent of cardiovascular risk. This has also been emphasized by the DECODE-study.

Antihyperglycaemic therapy in elderly patients with type 2 diabetes: potential role of incretin mimetics and DPP-4 inhibitors

Management of elderly patients with type II diabetes is complicated by age-related changes in physiology, comorbidities, polypharmacy and heterogeneity of functional status. A minimum goal in antidiabetic treatment in this population is to achieve a level of glycaemic control that avoids acute complications of diabetes, adverse effects and reduction in quality of life. Hypoglycaemia is a particular problem in elderly patients, and many antidiabetic agents pose increased risk for hypoglycaemia. In addition, many standard agents pose risks for older patients because of reduced renal function and common comorbidities. Newer agents based on enhancing incretin activity, including the glucagon-like peptide-1 mimetics exenatide and liraglutide and the oral dipeptidyl peptidase-4 inhibitors sitagliptin and vildagliptin, may offer particular advantages in elderly patients with diabetes.

Impact of renal dysfunction and glucometabolic status on one month mortality after acute myocardial infarction

Patients with impaired glucometabolic status or renal function have a higher mortality after acute myocardial infarction. It is unclear whether this higher risk is independent or related to the quality of care. In a prospective registry, stress hyperglycaemia (SH) was defined as glucose level>140 mg/dl. Renal function was assessed by the glomerular filtration rate (GFR): normal (>/=60), mild (30-60) and severe dysfunction (<30 ml/min/1.72 m(2)). The level of risk was assessed by the TIMI risk index and the quality of care by the rate of use of five guidelines-recommended treatments. Among the 1388 patients included, 23% had diabetes, 16% had SH, renal function was normal in 55%, mildly impaired in 35% and severely impaired in 9.5%. At one month, the mortality rate was higher in patients with SH (18%) as compared with diabetics (9%) or those with normal glucometabolic status (5%). Similarly, the mortality rate was higher in those with impaired renal function. Multivariable analysis identified SH, GFR group, TIMI risk index, ST segment elevation MI and quality of care as independent predictors of one-month mortality. In patients with acute MI, SH and GFR<30 ml/min/m(2) are independent predictors of mortality after adjustment for the level of risk and acute care.

Improved but still high short- and long-term mortality rates after myocardial infarction in patients with diabetes mellitus: a time-trend report from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admission

OBJECTIVE

The aim of the study was to compare time-trends in mortality rates and treatment patterns between patients with and without diabetes based on the Swedish register of coronary care (Register of Information and Knowledge about Swedish Heart Intensive Care Admission [RIKS-HIA]).

METHODS

Post myocardial infarction mortality rate is high in diabetic patients, who seem to receive less evidence-based treatment. Mortality rates and treatment in 1995-1998 and 1999-2002 were studied in 70,882 patients (age <80 years), 14 873 of whom had diabetes (the first registry recorded acute myocardial infarction), following adjustments for differences in clinical and other parameters.

RESULTS

One-year mortality rates decreased from 1995 to 2002 from 16.6% to 12.1% in patients without diabetes and from 29.7% to 19.7%, respectively, in those with diabetes. Patients with diabetes had an adjusted relative 1-year mortality risk of 1.44 (95% CI 1.36 to 1.52) in 1995-1998 and 1.31 (95% CI 1.24 to 1.38) in 1999-2002. Despite improved pre-admission and in-hospital treatment, diabetic patients were less often offered acute reperfusion therapy (adjusted OR 0.85, 95% CI 0.80 to 0.90), acute revascularisation (adjusted OR 0.78, 95% CI 0.69 to 0.87) or revascularisation within 14 days (OR 0.80, 95% CI 0.75 to 0.85), aspirin (OR 0.90, 95% CI 0.84 to 0.98) and lipid-lowering treatment at discharge (OR 0.81, 95% CI 0.77 to 0.86).

CONCLUSION

Despite a clear improvement in the treatment and myocardial infarction survival rate in patients with diabetes, mortality rate remains higher than in patients without diabetes. Part of the excess mortality may be explained by co-morbidities and diabetes itself, but a lack of application of evidence-based treatment also contributes, underlining the importance of the improved management of diabetic patients.

Implications of hyperglycaemia and ethnicity in patients with acute coronary syndromes in New Zealand

BACKGROUND

Admission blood glucose (ABG) is an independent predictor of death in patients with acute ST elevation myocardial infarction (STEMI). In New Zealand, mortality following myocardial infarction is disproportionally higher in Maori. Little information, however, exists concerning the predictive value of ABG in non-ST elevation acute coronary syndromes (NSTEACS) events or indeed if similar ethnic differences exist in outcome in this patient population.

AIM

To assess the predictive value of ABG and ethnicity in individuals admitted with acute coronary syndromes (ACS) on mortality.

METHODS

A retrospective analysis of hospital discharge diagnosis of all ACS between 1 January 1999 and 31 December 2002 at Waikato hospital, Hamilton, New Zealand. The primary outcome was all-cause mortality.

RESULTS

There were 4408 episodes of ACS with 1091 (25%) due to STEMI. There were 806 (18%) deaths. The presence of diabetes mellitus (DM) or an elevated ABG, in the absence of a history of DM, was associated with poor patient outcome. Early mortality is seen in individuals presenting with STEMI. People in the highest glucose category were older, more likely to be Maori, had a higher percentage of people with diabetes and remained in hospital longer, regardless of ACS type, than those in the lowest glucose category. Diabetes was more common in Maori (33%) than in Europeans (17.5%); p < 0.001. Significant risk factors for mortality were age, gender, diabetes, ethnicity, glucose and STEMI. For each mmol/l increase in glucose there is a 4.3% increase risk of dying. Adjusting for age and gender, Maori have a much higher mortality than Europeans (RR 2.12; p < 0.00001) regardless of ACS type (STEMI or NSTEACS).

CONCLUSIONS

Our study confirms the higher mortality following ACS, of Maori compared to New Zealanders of European origin. A raised ABG is a marker of this increased risk in all patients with ACS.

Impaired glucose tolerance, diabetes, and cardiovascular disease

OBJECTIVE

To analyze the association among impaired glucose tolerance (IGT), diabetes, and cardiovascular disease (CVD).

METHODS

We review current studies that have addressed the foregoing relationship and summarize the results of diagnostic and therapeutic interventions.

RESULTS

A major cause of the reduction in life expectancy in patients with diabetes is CVD and cardiovascular complications. Both prediabetes and diabetes predispose to cardiovascular alterations. IGT and even the upper normal values of nondiabetic glucose levels are associated with an increased cardiovascular risk. The risk of heart disease can be increased as early as 15 years before the diagnosis of diabetes. Patients with chronic or acute CVD and no previous diagnosis of diabetes frequently present with either IGT or diabetes. Thus, such patients should undergo screening for diabetes with an oral glucose tolerance test. In acute coronary syndromes, lowering of glucose levels to the near-normal range by administration of insulin is highly beneficial. Early, rigorous interventions to improve metabolic control will yield better cardiovascular outcomes in patients with dysglycemia.

CONCLUSION

Aggressive preventive and treatment strategies, which can include multiple interventions, are needed to minimize the potential effects of CVD in patients with diabetes or IGT.

The Links between Diabetes and Cardiovascular Disease

The aim of this study was to review current studies relevant to the link between impaired glucose tolerance (IGT), diabetes, and cardiovascular disease. Cardiovascular disease is a major cause of the reduction in life expectancy in patients with diabetes. Seventy-five percent of diabetic patients die prematurely of cardiovascular complications. Both prediabetes and diabetes highly pre-dispose to cardiovascular alterations. IGT and even the upper-normal of nondiabetic glucose values are associated with an increased cardiovascular risk. The risk of heart disease is increased up to 15 years prior diagnosis of diabetes. Patients with chronic or acute cardiovascular disease and no previous diagnosis of diabetes frequently present with either IGT or diabetes. Patients with cardiovascular disease and no previous diagnosis of diabetes need to be screened for diabetes with an oral glucose tolerance test. In acute coronary syndromes, lowering glucose levels to the near-normal range with insulin is highly beneficial. Early and rigorous improvement of metabolic control is highly supportive in improving the cardiovascular outcome in patients with dysglycemia. Preventive treatment strategies, which include multiple approaches, are required to overcome the burden of cardiovascular disease in diabetes and IGT.

Intense metabolic control by means of insulin in patients with diabetes mellitus and acute myocardial infarction (DIGAMI 2): effects on mortality and morbidity

AIMS

Patients with diabetes have an unfavourable prognosis after an acute myocardial infarction. In the first DIGAMI study, an insulin-based glucose management improved survival. In DIGAMI 2, three treatment strategies were compared: group 1, acute insulin-glucose infusion followed by insulin-based long-term glucose control; group 2, insulin-glucose infusion followed by standard glucose control; and group 3, routine metabolic management according to local practice.

METHODS AND RESULTS

DIGAMI 2 recruited 1253 patients (mean age 68 years; 67% males) with type 2 diabetes and suspected acute myocardial infarction randomly assigned to groups 1 (n=474), 2 (n=473), and 3 (n=306). The primary endpoint was all-cause mortality between groups 1 and 2, and a difference was hypothesized as the primary objective. The secondary objective was to compare total mortality between groups 2 and 3, whereas morbidity differences served as tertiary objectives. The median study duration was 2.1 (interquartile range 1.03-3.00) years. At randomization, HbA1c was 7.2, 7.3, and 7.3% in groups 1, 2, and 3, respectively, whereas blood glucose was 12.8, 12.5, and 12.9 mmol/L, respectively. Blood glucose was significantly reduced after 24 h in all groups, more in groups 1 and 2 (9.1 and 9.1 mmol/L) receiving insulin-glucose infusion than in group 3 (10.0 mmol/L). Long-term glucose-lowering treatment differed between groups with multidose insulin (> or =3 doses/day) given to 15 and 13% of patients in groups 2 and 3, respectively compared with 42% in group 1 at hospital discharge. By the end of follow-up, HbA1c did not differ significantly among groups 1-3 ( approximately 6.8%). The corresponding values for fasting blood glucose were 8.0, 8.3, and 8.6 mmol/L. Hence, the target fasting blood glucose for patients in group 1 of 5-7 mmol/L was never reached. The study mortality (groups 1-3 combined) was 18.4%. Mortality between groups 1 (23.4%) and 2 (22.6%; primary endpoint) did not differ significantly (HR 1.03; 95% CI 0.79-1.34; P=0.831), nor did mortality between groups 2 (22.6%) and 3 (19.3%; secondary endpoint) (HR 1.23; CI 0.89-1.69; P=0.203). There were no significant differences in morbidity expressed as non-fatal reinfarctions and strokes among the three groups.

CONCLUSION

DIGAMI 2 did not support the fact that an acutely introduced, long-term insulin treatment improves survival in type 2 diabetic patients following myocardial infarction when compared with a conventional management at similar levels of glucose control or that insulin-based treatment lowers the number of non-fatal myocardial reinfarctions and strokes. However, an epidemiological analysis confirms that the glucose level is a strong, independent predictor of long-term mortality in this patient category, underlining that glucose control seems to be an important part of their management.

Unique characteristics of the geriatric diabetic population and the role for therapeutic strategies that enhance glucagon-like peptide-1 activity

PURPOSE OF REVIEW

Care for elderly diabetic patients poses a unique clinical challenge. This review highlights distinct aspects of the pathophysiology and the risks for secondary complications in the geriatric diabetic population. Based on these considerations, we discuss emerging therapeutic options based on the actions of the incretin hormone glucagon-like peptide (GLP)-1, which may be ideal for achieving glycemic control in the elderly diabetic patient.

RECENT FINDINGS

Aging is associated with diminished capacity of pancreatic beta-cells to respond to glucose. This functional decline in beta-cell insulin secretion is a major contributor to the development of diabetes in the older patient. In addition, elderly diabetics suffer from a broader range of diabetic complications than do younger diabetics, warranting aggressive glycemic control. GLP-1 is known to improve beta-cell insulin secretion, increase beta-cell mass, and suppress glucagon secretion. Recent studies investigating improved GLP-1 activity have yielded promising results, with improved glycemic control in elderly patients with type 2 diabetes and without significant risk for hypoglycemia.

SUMMARY

Elderly diabetics are a growing subset of the type 2 diabetic population with unique pathophysiologic characteristics and diabetic risk profiles. Therapeutic strategies that incorporate enhancement of GLP-1 action on beta-cells to improve beta-cell insulin secretion and glycemic control may be ideal for this distinct population and should be validated with further long-term clinical studies.

New aspects in the pathogenesis of diabetic atherothrombosis

Diabetes mellitus is increasing worldwide, resulting from the interaction of obesity, inflammation, and hyperglycemia. Activated immunity and cytokine production lead to insulin resistance and other components of the metabolic syndrome, establishing the link between diabetes and atherosclerosis. Hyperglycemia-induced endothelial dysfunction is mediated by increased oxidative stress, a promoter of adventitial inflammation and vasa vasorum neovascularization in experimental models of diabetic atherosclerosis. Recent studies have documented increased inflammation, neovascularization, and intraplaque hemorrhage in human diabetic atherosclerosis. This inflammatory microangiopathic process is independently associated with plaque rupture, leading to coronary thrombosis. Tissue factor, the most potent trigger of the coagulation cascade, is increased in diabetic patients with poor glycemic control. Circulating tissue factor microparticles are also associated with apoptosis of plaque macrophages, closing the link among inflammation, plaque rupture, and blood thrombogenicity. High-density lipoproteins, responsible for free cholesterol removal, are reduced in patients with insulin resistance and diabetes. High-density lipoprotein therapy leads to a significant decrease in plaque macrophages and increase in smooth-muscle cells. These beneficial effects may be responsible for coronary plaque stabilization in patients treated with recombinant Apolipoprotein A-I Milano/phospholipid complex. Finally, peroxisomal proliferator-activated receptors (PPARs) are now considered the nuclear transcriptional regulators of atherosclerosis. Three subfamilies, including PPAR-alpha, -delta, and -gamma, have been identified with crucial roles in lipid metabolism, plaque inflammation, expression of adhesion molecules and cytokines, and regulation of matrix metalloproteinases. Multiple experimental studies have documented plaque stabilization with PPAR-gamma agonists, a group of medications holding great promise in the treatment of diabetes atherosclerosis.