Emerging concepts in the management of acute myocardial infarction in patients with diabetes mellitus

Diabetes mellitus in transfemoral transcatheter aortic valve implantation: a propensity matched analysis

BACKGROUND

Diabetes Mellitus (DM) affects a third of patients with symptomatic severe aortic valve stenosis undergoing transcatheter aortic valve implantation (TAVI). DM is a well-known risk factor for cardiac surgery, but its prognostic impact in TAVI patients remains controversial. This study aimed to evaluate outcomes in diabetic patients undergoing TAVI.

METHODS

This multicentre registry includes data of > 12,000 patients undergoing transfemoral TAVI. We assessed baseline patient characteristics and clinical outcomes in patients with DM and without DM. Clinical outcomes were defined by the second valve academic research consortium. Propensity score matching was applied to minimize potential confounding.

RESULTS

Of the 11,440 patients included, 31% (n = 3550) had DM and 69% (n = 7890) did not have DM. Diabetic patients were younger but had an overall worse cardiovascular risk profile than non-diabetic patients. All-cause mortality rates were comparable at 30 days (4.5% vs. 4.9%, RR 0.9, 95%CI 0.8-1.1, p = 0.43) and at one year (17.5% vs. 17.4%, RR 1.0, 95%CI 0.9-1.1, p = 0.86) in the unmatched population. Propensity score matching obtained 3281 patient-pairs. Also in the matched population, mortality rates were comparable at 30 days (4.7% vs. 4.3%, RR 1.1, 95%CI 0.9-1.4, p = 0.38) and one year (17.3% vs. 16.2%, RR 1.1, 95%CI 0.9-1.2, p = 0.37). Other clinical outcomes including stroke, major bleeding, myocardial infarction and permanent pacemaker implantation, were comparable between patients with DM and without DM. Insulin treated diabetics (n = 314) showed a trend to higher mortality compared with non-insulin treated diabetics (n = 701, Hazard Ratio 1.5, 95%CI 0.9-2.3, p = 0.08). EuroSCORE II was the most accurate risk score and underestimated 30-day mortality with an observed-expected ratio of 1.15 in DM patients, STS-PROM overestimated actual mortality with a ratio of 0.77 and Logistic EuroSCORE with 0.35.

CONCLUSION

DM was not associated with mortality during the first year after TAVI. DM patients undergoing TAVI had low rates of mortality and other adverse clinical outcomes, comparable to non-DM TAVI patients. Our results underscore the safety of TAVI treatment in DM patients.

TRIAL REGISTRATION

The study is registered at clinicaltrials.gov (NCT03588247).

Very early invasive angiography versus standard of care in higher-risk non-ST elevation myocardial infarction: study protocol for the prospective multicentre randomised controlled RAPID N-STEMI trial

BACKGROUND

There are a paucity of randomised data on the optimal timing of invasive coronary angiography (ICA) in higher-risk patients with non-ST elevation myocardial infarction (N-STEMI). International guideline recommendations for early ICA are primarily based on retrospective subgroup analyses of neutral trials.

AIMS

The RAPID N-STEMI trial aims to determine whether very early percutaneous revascularisation improves clinical outcomes as compared with a standard of care strategy in higher-risk N-STEMI patients.

METHODS AND ANALYSIS

RAPID N-STEMI is a prospective, multicentre, open-label, randomised-controlled, pragmatic strategy trial. Higher-risk N-STEMI patients, as defined by Global Registry of Acute Coronary Events 2.0 score ≥118, or >90 with at least one additional high-risk feature, were randomised to either: very early ICA±revascularisation or standard of care timing of ICA±revascularisation. The primary outcome is the proportion of participants with at least one of the following events (all-cause mortality, non-fatal myocardial infarction and hospital admission for heart failure) at 12 months. Key secondary outcomes include major bleeding and stroke. A hypothesis generating cardiac magnetic resonance (CMR) substudy will provide mechanistic data on infarct size, myocardial salvage and residual ischaemia post percutaneous coronary intervention. On 7 April 2021, the sponsor discontinued enrolment due to the impact of the COVID-19 pandemic and lower than expected event rates. 425 patients were enrolled, and 61 patients underwent CMR.

ETHICS AND DISSEMINATION

The trial has been reviewed and approved by the East of England Cambridge East Research Ethics Committee (18/EE/0222). The study results will be submitted for publication within 6 months of completion.

TRIAL REGISTRATION NUMBER

NCT03707314; Pre-results.

Clinical outcomes of patients with diabetes mellitus and acute ST-elevation myocardial infarction following fibrinolytic therapy: a nationwide inpatient sample (NIS) database analysis

The impact of diabetes mellitus (DM) on clinical outcomes of acute ST-segment elevation myocardial infarction (STEMI) following fibrinolytic therapy remains uncertain. We queried the National Inpatient Sample (NIS) for STEMI patients who received fibrinolytic therapy. Categorical and continuous variables were compared using the unadjusted odds ratio (uOR) and t-test analysis, respectively. A binary logistic regression model was used to control the outcomes for patient demographics, procedural characteristics, and baseline comorbidities. A total of 111,155 (no-DM 84,146, DM 27,009) were included. The unadjusted odds of in-hospital mortality (8.4% vs. 6.8%, uOR 1.25, 95% CI 1.19-1.31, P = <0.0001) and cardiogenic shock (7.7% vs. 6.2%, uOR 1.26, 95% CI 1.20-1.33, P = <0.0001) were significantly higher in patients with DM compared to those with no DM, respectively. The odds for major bleeding and cardiopulmonary arrest were significantly lower for in diabetes. The adjusted pooled estimates mirrored the unadjusted findings. Diabetic patients receiving fibrinolytic therapy for STEMI might have higher odds of all-cause mortality and cardiogenic shock compared to non-diabetic patients.

A Review of Cardiovascular Outcomes Trials of Glucose-Lowering Therapies and Their Effects on Heart Failure Outcomes

Type 2 diabetes mellitus has long been recognized as a major risk factor for adverse atherosclerotic cardiovascular disease events; however, recent data indicate that heart failure is now emerging as the most common and morbid cardiovascular complication of type 2 diabetes mellitus. When heart failure develops in patients with type 2 diabetes, prognosis is ominous, highlighting the need for glucose-lowering therapies that can prevent heart failure, improve outcomes, or both. Prior to 2008, there was a paucity of randomized controlled trials evaluating long-term cardiovascular outcomes with glucose-lowering therapies. This changed after guidance on the assessment of novel glucose-lowering agents was issued by both the US Food and Drug Administration and the European Medicines Agency. Since then, significant progress has been made as a result of large cardiovascular outcomes trials. Though randomized controlled trials on insulin, sulfonylureas, and metformin are still limited, cardiovascular outcomes trials on newer glucose-lowering agents have included hundreds of thousands of patients with multiple years of follow-up. The increased risk of thiazolidinediones on heart failure had been well theorized and is now established; however, the increase in heart failure hospitalization with certain dipeptidyl peptidase-4 inhibitors was unexpected. The reasons for discrepancies with regard to heart failure risk with different dipeptidyl peptidase-4 inhibitors remain unclear, and further mechanistic studies are ongoing. The role of glucagon-like peptide-1 receptor agonists among patients with heart failure also remains unclear, and their effects may differ in patients with and without established heart failure, particularly those with decompensated heart failure with reduced ejection fraction.

Review: The management of acute myocardial infarction in patients with diabetes mellitus

Diabetic subjects are more likely to experience a myocardial infarction and have worse outcomes compared to non-diabetic subjects. The underlying pathophysiology of the atherosclerotic process is not significantly different in diabetic subjects, but the prothrombotic and procoagulant state with which diabetes is associated is thought to contribute to the higher incidence of and worse prognosis after myocardial infarction. Difficulties of re-establishing vessel patency by thrombolytic or mechanical means contribute to the high morbidity and mortality. The diffuse nature of arterial disease with accompanying metabolic derangement contribute to impaired compensatory mechanisms, increased infarct size and a disproportionately more substantial impairment of left ventricular function. The newer adjuvant antithrombotic and anticoagulant agents have particular roles in management therefore and careful modulation of glucose metabolism in the acute and follow-up phase of an infarct may favourably influence outcome.

The association of cardiac function, structure, and glycemic control in patients with old myocardial infarction: a study using cardiac magnetic resonance

Purpose

Cardiac magnetic resonance imaging (MRI) can provide noninvasive and accurate quantitative assessment of the left ventricular (LV) structure and function. We investigated the association between LV MRI measures and glycemic control in patients with old myocardial infarction (OMI).

Materials and methods

The study population consisted of 51 OMI patients. By using a 1.5-T MRI scanner, we acquired cine MRI and late gadolinium-enhanced MRI. We calculated the LV volume, LV mass (LVM), LV function and percentage of infarcted myocardial volume over the total LV myocardial volume (%LGE). Patients were allocated to three groups: normal glucose tolerance (NGT), n = 9; impaired glucose tolerance (IGT)/impaired fasting glucose (IFG), n = 15; diabetes mellitus (DM), n = 27; respectively.

Results

LVM was significantly increased in the DM group compared with the NGT group (p = 0.002). Multiple linear regression analysis demonstrated that HbA1c levels were significantly and independently associated with LVM after adjustment for risk factors of congestive heart failure and  %LGE (p = 0.009). The LV ejection fraction (EF) was not associated with HbA1c levels.

Conclusion

Our findings suggest that glucose tolerance in patients with OMI may be associated with LV wall thickness. LVM calculation by cine MRI might be useful for longitudinal follow-up of the effect of diabetic treatment on OMI patients.

Diabetes-associated macrovascular complications: cell-based therapy a new tool?

Diabetes mellitus and its ongoing macrovascular complications represent one of the major health problems around the world. Rise in obesity and population ages correlate with the increased incidence of diabetes. This highlights the need for novel approaches to prevent and treat this pandemic. The discovery of a reservoir of stem/progenitors in bone marrow and in mesenchymal tissue has attracted interest of both biologists and clinicians. A number of preclinical and clinical trials were developed to explore their potential clinical impact, as target or vehicle, in different clinical settings, including diabetes complications. Currently, bone marrow, peripheral blood, mesenchymal, and adipose tissues have been used as stem/progenitor cell sources. However, evidences have been provided that both bone marrow and circulating progenitor cells are dysfunctional in diabetes. These observations along with the growing advantages in genetic manipulation have spurred researchers to exploit ex vivo manipulated cells to overcome these hurdles. In this article, we provide an overview of data relevant to stem-progenitors potential clinical application in revascularization and/or vascular repair. Moreover, the hurdles at using progenitor cells in diabetic patients will be also discussed.

Transcatheter versus surgical aortic valve replacement in patients with diabetes and severe aortic stenosis at high risk for surgery: an analysis of the PARTNER Trial (Placement of Aortic Transcatheter Valve)

OBJECTIVES

The goal of this study was to determine whether a less-invasive approach to aortic valve replacement (AVR) improves clinical outcomes in diabetic patients with aortic stenosis (AS).

BACKGROUND

Diabetes is associated with increased morbidity and mortality after surgical AVR for AS.

METHODS

Among treated patients with severe symptomatic AS at high risk for surgery in the PARTNER (Placement of Aortic Transcatheter Valve) trial, we examined outcomes stratified according to diabetes status of patients randomly assigned to receive transcatheter or surgical AVR. The primary outcome was all-cause mortality at 1 year.

RESULTS

Among 657 patients enrolled in PARTNER who underwent treatment, there were 275 patients with diabetes (145 transcatheter, 130 surgical). There was a significant interaction between diabetes and treatment group for 1-year all-cause mortality (p = 0.048). Among diabetic patients, all-cause mortality at 1 year was 18.0% in the transcatheter group and 27.4% in the surgical group (hazard ratio: 0.60 [95% confidence interval: 0.36 to 0.99]; p = 0.04). Results were consistent among patients treated via transfemoral or transapical routes. In contrast, among nondiabetic patients, there was no significant difference in all-cause mortality at 1 year (p = 0.48). Among diabetic patients, the 1-year rates of stroke were similar between treatment groups (3.5% transcatheter vs. 3.5% surgery; p = 0.88), but the rate of renal failure requiring dialysis >30 days was lower in the transcatheter group (0% vs. 6.1%; p = 0.003).

CONCLUSIONS

Among patients with diabetes and severe symptomatic AS at high risk for surgery, this post-hoc stratified analysis of the PARTNER trial suggests there is a survival benefit, no increase in stroke, and less renal failure from treatment with transcatheter AVR compared with surgical AVR. (The PARTNER Trial: Placement of AoRTic TraNscathetER Valve Trial; NCT00530894).

Decreased long-chain fatty acid oxidation impairs postischemic recovery of the insulin-resistant rat heart

Diabetic patients with acute myocardial infarction are more likely to die than nondiabetic patients. In the present study we examined the effect of insulin resistance on myocardial ischemia tolerance. Hearts of rats, rendered insulin resistant by high-sucrose feeding, were subjected to ischemia/reperfusion ex vivo. Cardiac power of control hearts from chow-fed rats recovered to 93%, while insulin-resistant hearts recovered only to 80% (P<0.001 vs. control). Unexpectedly, impaired contractile recovery did not result from an impairment of glucose oxidation (576±36 vs. 593±42 nmol/min/g dry weight; not significant), but from a failure to increase and to sustain oxidation of the long-chain fatty acid oleate on reperfusion (1878±56 vs. 2070±67 nmol/min/g dry weight; P<0.05). This phenomenon was due to a reduced ability to transport oleate into mitochondria and associated with a 38-58% decrease in the mitochondrial uncoupling protein 3 (UCP3) levels. Contractile function was rescued by replacing oleate with a medium-chain fatty acid or by restoring UCP3 levels with 24 h of food withdrawal. Lastly, the knockdown of UCP3 in rat L6 myocytes also decreased oleate oxidation by 13-18% following ischemia. Together the results expose UCP3 as a critical regulator of long-chain fatty acid oxidation in the stressed heart postischemia and identify octanoate as an intervention by which myocardial metabolism can be manipulated to improve function of the insulin-resistant heart.

Characteristics, management, and in-hospital outcomes of diabetic patients with acute coronary syndrome in the United Arab Emirates

We describe the baseline characteristics, management, and in-hospital outcomes of patients in the United Arab Emirates (UAE) with DM admitted with an acute coronary syndrome (ACS) and assess the influence of DM on in-hospital mortality. Data was analyzed from 1697 patients admitted to various hospitals in the UAE with a diagnosis of ACS in 2007 as part of the 1st Gulf RACE (Registry of Acute Coronary Events). Of 1697 patients enrolled, 668 (39.4%) were diabetics. Compared to patients without DM, diabetic patients were more likely to have a past history of coronary artery disease (49.1% versus 30.1%, P < 0.001), hypertension (67.2% versus 36%, P < 0.001), and prior revascularization (21% versus 11.4%, P < 0.001). They experienced more in-hospital recurrent ischemia (8.5% versus 5.1%; P = 0.004) and heart failure (20% versus 10%; P < 0.001). The mortality rate was 2.7% for diabetics and 1.6% for nondiabetics (P = 0.105). After age adjustment, in-hospital mortality increased by 3.5% per year of age (P = 0.016). This mortality was significantly higher in females than in males (P = 0.04). ACS patients with DM have different clinical characteristics and appear to have poorer outcomes.

Omega-3 polyunsaturated Fatty acids and heart rate variability

Omega-3 polyunsaturated fatty acids (PUFA) may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD). The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV) can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arrhythmic events. Studies on HRV and omega-3 PUFA have been performed in several populations such as patients with ischemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects as well as in children. The studies have demonstrated a positive association between cellular content of omega-3 PUFA and HRV and supplementation with omega-3 PUFA seems to increase HRV which could be a possible explanation for decreased risk of arrhythmic events and SCD sometimes observed after omega-3 PUFA supplementation. However, the results are not consistent and further research is needed.

The adverse impact of diabetes mellitus on left ventricular remodeling and function in patients with severe aortic stenosis

BACKGROUND

The diabetic heart exhibits increased left ventricular (LV) mass and reduced ventricular function. However, this relationship has not been studied in patients with aortic stenosis (AS), a disease process that causes LV hypertrophy and dysfunction through a distinct mechanism of pressure overload. The aim of this study was to determine how diabetes mellitus (DM) affects LV remodeling and function in patients with severe AS.

METHODS AND RESULTS

Echocardiography was performed on 114 patients with severe AS (mean aortic valve area [AVA], 0.6 cm(2)) and included measures of LV remodeling and function. Multivariable linear regression models investigated the independent effect of DM on these aspects of LV structure and function. Compared to patients without diabetes (n=60), those with diabetes (n=54) had increased LV mass and LV end-systolic and end-diastolic dimensions, and decreased LV ejection fraction (EF) and longitudinal systolic strain (all P<0.01). In multivariable analyses adjusting for age, sex, systolic blood pressure, AVA, body surface area, and coronary disease, DM was an independent predictor of increased LV mass (β=26 g, P=0.01), LV end-systolic dimension (β=0.5 cm, P=0.008), and LV end-diastolic dimension (β=0.3 cm, P=0.025). After also adjusting for LV mass, DM was associated with reduced longitudinal systolic strain (β=1.9%, P=0.023) and a trend toward reduced EF (β=-5%, P=0.09). Among patients with diabetes, insulin use (as a marker of disease severity) was associated with larger LV end-systolic dimension and worse LV function. LV mass was a strong predictor of reduced EF and systolic strain (both P<0.001).

CONCLUSIONS

DM has an additive adverse effect on hypertrophic remodeling (increased LV mass and larger cavity dimensions) and is associated with reduced systolic function in patients with AS beyond known factors of pressure overload.

Stem cells in the diabetic infarcted heart

Diabetes mellitus is one of the leading causes of death, and the majority of these deaths are associated with cardiovascular diseases. Development and progression of myocardial infarction leading to heart failure is much more complex and multifactorial in diabetics compared with non-diabetics. Despite significant advances in pharmacological interventions and surgical techniques, the disease progression leading to diabetic end-stage heart failure remains very high. Recently, cell therapy has gained much attention as an alternative approach to treat various heart diseases. However, transplanted stem cell studies in diabetic animal models are very limited. In this review, we discuss the pathogenesis of the diabetic infarcted heart and the potential of stem cell therapy to repair and regenerate.

Inflammatory markers and cardiac function in acute coronary syndrome: difference in ST-segment elevation myocardial infarction (STEMI) and in non-STEMI models

PURPOSE

No studies have been addressed to the differences in inflammation kinetics between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI).

PATIENTS AND METHODS

Forty consecutive patients with acute coronary syndrome (ACS) (n=23 STEMI, age=61.7+/-10.3 years; n=17 NSTEMI, age=65.6+/-11.3 years) were enrolled within 12h after symptoms. All patients received therapy according to the current Guidelines. Blood samples were collected at admission (t0), on days 7 (t1) and 30 (t2) to evaluate CD40 ligand (CD40L), transforming growth factor (TGF)-beta, interleukin (IL)-6, tumor necrosis factor (TNF)-alpha and its receptors TNFRI and TNFRII, high sensitivity C-reactive protein (hs-CRP), serum amyloid A (SAA) and white blood cells (WBC). Echocardiographic parameters were also evaluated.

RESULTS

STEMI patients, at admission, had significantly higher median values of hs-CRP (p<0.001), WBC (p<0.01), ferritin (p<0.0005) and IL-6 (p<0.05) than NSTEMI. On the contrary, NSTEMI patients had lower median levels of every inflammatory marker except for CD40L (p<0.05) that was significantly higher. Moreover, three out of four deceased patients presented levels of CD40L higher than the median. At admission, STEMI showed a reduced ejection fraction (EF, p<0.01) and increased wall motion score index (WMSI, p<0.001) and end-diastolic volume (EDV, p<0.05) vs NSTEMI. An inverse correlation between admission values of inflammatory markers (SAA and WBC) and cardiac function was observed (p<0.05). Moreover, the necrosis marker troponin I was positively correlated with both WMSI (p<0.05) and hs-CRP (p<0.05). Regarding the inflammation kinetics, a difference was observed in the two groups only for WBC (p<0.05) and SAA (p<0.05). SAA showed higher values in STEMI at t0 and t1. In both groups, TGF-beta had an increase at t1 and t2 with respect to admission, while IL-6 had a decreasing trend. The total incidence of major adverse clinical events (MACE) was 22.5% at t2, with a mortality rate of 10%.

CONCLUSION

These observations suggest a differential inflammatory pattern in STEMI and NSTEMI patients. The absence of significant correlations between inflammatory indexes and myocardial infarction in NSTEMI supports the hypothesis that a different pattern of inflammation occurs in these patients. CD40L may have an important role as a marker for risk stratification in patients with ACS.

Does reperfusion in the treatment of acute myocardial infarction improve the prognosis of acute myocardial infarction in diabetic patients?

BACKGROUND

Diabetic patients have a 6-fold increased mortality in acute coronary syndromes.

HYPOTHESIS

Different therapeutic strategies in diabetics with acute coronary syndromes have an impact on in-hospital and long-term prognosis.

METHODS

A total of 889 consecutive patients with ST-segment elevation myocardial infarction were included and followed-up for at least 6 months. The study population consisted of 168 (18.9%) diabetic patients and 721 nondiabetics.

RESULTS

Invasive therapy and fibrinolysis were less frequently used in diabetic patients (38.7% versus 50.2%; p = 0.0071 and 8.3% versus 15%; p = 0.024, respectively). In-hospital mortality in diabetic individuals was almost twice as high as in nondiabetic subjects (20.2% versus 11.1%; p < 0.0014). In-hospital mortality was slightly higher in diabetic patients undergoing primary percutaneous transluminal coronary angioplasty (PTCA; 8.3% versus 4.8%; p = 0.35), but lower in those treated with fibrinolysis (7.7% versus 16%; p = 0.7) compared with the rest of the patients. At 6-mo follow-up mortality was significantly higher in diabetic subjects as compared with nondiabetic subjects (28.0% versus 15.1%; p < 0.0001). The highest number of deaths was found in individuals receiving conservative treatment with diabetic subjects significantly outnumbering nondiabetic individuals (40.1% versus 27.9%; p = 0.028 at 6 mo). Both in-hospital and 6-mo mortality were similar in diabetics and nondiabetics receiving reperfusion therapy (7.1% versus 8.2%; p < 0.68 and 9.3% versus 15.3%; p < 0.098, respectively).

CONCLUSION

Reperfusion therapy, both fibrinolysis and the invasive approach, reduced in-hospital mortality from that observed in nondiabetic individuals.

A copper(II)-selective chelator ameliorates left-ventricular hypertrophy in type 2 diabetic patients: a randomised placebo-controlled study

AIMS/HYPOTHESIS

Cu(II)-selective chelation with trientine ameliorates cardiovascular and renal disease in a model of diabetes in rats. Here, we tested the hypothesis that Cu(II)-selective chelation might improve left ventricular hypertrophy (LVH) in type 2 diabetic patients.

METHODS

We performed a 12 month randomised placebo-controlled study of the effects of treatment with the Cu(II)-selective chelator trientine (triethylenetetramine dihydrochloride, 600 mg given orally twice daily) on LVH in diabetic patients (n = 15/group at baseline) in an outpatient setting wherein participants, caregivers and those assessing outcomes were blinded to group assignment. Using MRI, we measured left ventricular variables at baseline, and at months 6 and 12. The change from baseline in left ventricular mass indexed to body surface area (LVM(bsa)) was the primary endpoint variable.

RESULTS

Diabetic patients had LVH with preserved ejection fraction at baseline. Trientine treatment decreased LVM(bsa) by 5.0 +/- 7.2 g/m(2) (mean +/- SD) at month 6 (when 14 trientine-treated and 14 placebo-treated participants were analysed; p = 0.0056 compared with placebo) and by 10.6 +/- 7.6 g/m(2) at month 12 (when nine trientine-treated and 13 placebo-treated participants were analysed; p = 0.0088), whereas LVM(bsa) was unchanged by placebo treatment. In a multiple-regression model that explained ~75% of variation (R (2) = 0.748, p = 0.001), cumulative urinary Cu excretion over 12 months was positively associated with trientine-evoked decreases in LVM(bsa).

CONCLUSIONS/INTERPRETATION

Cu(II)-selective chelation merits further exploration as a potential pharmacotherapy for diabetic heart disease.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN 12609000053224 FUNDING: The Endocore Research Trust; Lottery Health New Zealand; the Maurice and Phyllis Paykel Trust; the Foundation of Research, Science and Technology (New Zealand); the Health Research Council of New Zealand; the Ministry of Education (New Zealand) through the Maurice Wilkins Centre for Molecular Biodiscovery; and the Protemix Corporation.

Symptoms of acute coronary syndrome in women with diabetes: an integrative review of the literature

OBJECTIVE

To review studies comparing multiple acute coronary syndrome (ACS) symptoms in white and Latina women with and without diabetes.

METHODS

This empirical integrative review summarizes 8 studies and identifies the limitations of research to date.

RESULTS

There are conflicting results about acute coronary syndrome (ACS) symptoms in women with diabetes. Differences were found in associated ACS symptoms and symptom characteristics; however, some studies found no differences in frequency of chest pain by diabetic status. Diabetes is an independent predictor of "atypical" presentation of acute myocardial infarction in women, and research to date suggests that shortness of breath may be an important ACS symptom in women with diabetes.

CONCLUSIONS

There is a paucity of literature on ACS symptoms in women, particularly Latina women, with diabetes, and results are inconclusive. Future research should examine the full range of ACS symptoms in multiethnic samples of women with diabetes.

Self-assembled PEG monolayer based SPR immunosensor for label-free detection of insulin

A simple and rapid continuous-flow immunosensor based on surface plasmon resonance (SPR) has been developed for detection of insulin as low as 1 ng ml-1 (ppb) with a response time of less than 5 min. At first, a heterobifunctional oligo(ethyleneglycol)-dithiocarboxylic acid derivative (OEG-DCA) containing dithiol and carboxyl end groups was used to functionalize the thin Au-film of SPR chip. Insulin was covalently bound to the Au-thiolate monolayer of OEG-DCA for activating the sensor surface to immunoaffinity interactions. An on-line competitive immunosensing principle is examined for detection of insulin, in which the direct affinity binding of anti-insulin antibody to the insulin on sensor surface is examined in the presence and absence of various concentrations of insulin. Immunoreaction of anti-insulin antibody with the sensor surface was optimized with reference to antibody concentration, sample analysis time and flow-rate to provide the desired detection limit and determination range. With the immunosensor developed, the lowest detectable concentration of insulin is 1 ng ml-1 and the determination range covers a wide concentration of 1-300 ng ml-1. The developed OEG-monolayer based sensor chip exhibited high resistance to non-specific adsorption of proteins, and an uninterrupted highly sensitive detection of insulin from insulin-impregnated serum samples has been demonstrated. After an immunoreaction cycle, active sensor surface was regenerated simply by a brief flow of an acidic buffer (glycine.HCl; pH 2.0) for less than 1 min. A same sensor chip was found reusable for more than 25 cycles without an appreciable change in the original sensor activity.

State of the Heart: Building Science to Improve Women’s Cardiovascular Health

Cardiovascular disease is the No. 1 killer of women in the United States, and marked disparities in cardiovascular health exist between women and men and among groups of women. Coronary heart disease is underdiagnosed, undertreated, and underresearched in women. Women with suspected heart disease are less likely than men to receive indicated diagnostic tests and procedures; sex-based biases in treatment of myocardial infarction persist; and women continue to be underrepresented in cardiovascular research. An accumulating body of literature points to 3 major explanations: sex-based physiology, provider bias, and psychosocial influences. Women’s acute and prodromal signs and symptoms of myocardial infarction have been described, yet women have difficulty recognizing and acting on these indications. Primary and secondary prevention of heart disease in women is imperative; although the science is lacking in several areas, existing evidence on diet, hormone therapy, aspirin, physical activity and obesity, and diabetes can serve as the basis for interventions. Potentially, large impacts could be made on women’s morbidity and mortality if current scientific knowledge were implemented. The state of the science of women and heart disease is reviewed, with a focus on those areas with the greatest potential to address the needs of women’s cardiovascular status. Key gaps in the science and remaining questions are presented as a research agenda for the coming decade.

Comparative early and late outcomes after primary percutaneous coronary intervention in ST-segment elevation and non-ST-segment elevation acute myocardial infarction (from the CADILLAC trial)

We determined the outcomes of patients with acute ST-segment elevation (STE) myocardial infarction (STEMI) and non-STEMI (NSTEMI) after primary percutaneous coronary intervention (PCI). The prognosis after primary PCI in STEMI has been extensively studied and defined. Outcomes of patients who undergo primary PCI for NSTEMI are less well established. In total, 2,082 patients with ongoing chest pain for > 30 minutes consistent with acute MI were randomized to balloon angioplasty versus stenting, each with/without abciximab. Of 1,964 patients, STEMI was present in 1,725 (87.8%) and NSTEMI in 239 (12.2%). Compared with STEMI, those with NSTEMI were more likely to have delayed time-to-hospital arrival (2.4 vs 1.8 hours, p = 0.0002) and increased door-to-balloon time (3.2 vs 1.9 hours, p < 0.0001). Patients with NSTEMI were more likely to have Thrombolysis In Myocardial Infarction grade 3 flow at baseline (37.3% vs 19.4%, p < 0.0001) and higher ejection fraction (58.7% vs 55.8%, p = 0.001), but similar rates of postprocedural Thrombolysis In Myocardial Infarction grade 3 flow. At 1 year, patients with NTEMI had similar mortality (3.4% vs 4.4%, p = 0.40) but higher rates of major adverse cardiac events (24.0% vs 16.6%, p = 0.007) that was driven by more frequent ischemic target vessel revascularization (21.8% vs 11.9%, p <0.0001). In conclusion, patients with acute MI without STE who are treated with primary PCI have marked delays to treatment, similar late mortality, and increased rates of ischemic target vessel revascularization compared with patients with STEMI, despite more favorable angiographic features at presentation and similar reperfusion success. The adverse prognosis of patients with NSTEMI should be recognized and efforts made to decrease reperfusion times.

Significado pronóstico de la diabetes mellitus en una población con insuficiencia cardíaca: mortalidad e ingreso por insuficiencia cardíaca al cabo de un año

BACKGROUND AND OBJECTIVE

The relationship between diabetes mellitus and heart failure is not fully established. The aim of the study was to assess the prevalence of diabetes and its prognostic significance, considering mortality and the need of hospital admission due to heart failure during the first year of follow-up, in an outpatient population with heart failure attended in a specialized Unit.

PATIENTS AND METHOD

We studied 362 patients -73% men; mean age (standard deviation) 65.3 (10.9) years-. Mean ejection fraction was 32.2% (12.7%). Patients were in New York Heart Association functional class I (5%), II (47%), III (43%) and IV (5%).

RESULTS

One-hundred forty-three out of 362 patients were diabetic (39.5%). Thirty patients (8%) died and 70 (19%) needed to be hospitalized due to heart failure during the first year of follow-up. One year mortality was 5% in non-diabetic patients and 13.3% in diabetic patients (p = 0.005). 13.2% of non-diabetic patients suffered at least one episode of heart failure needing hospital admission, whereas 28.7% of diabetic patients needed to be hospitalized at least once (p < 0.001). In the multivariate regression analysis, diabetes remained statistically associated both with mortality and with the need of heart failure related hospital admission.

CONCLUSIONS

Diabetes significantly correlated with a higher one year mortality as well as with a greater need of hospital admission due to heart failure. Prevalence of diabetes in a general population with heart failure was high.

The role of intensive glycemic control in the management of patients who have acute myocardial infarction

Hyperglycemia is associated with excess mortality in AMI and should be treated aggressively in the intensive care setting. The exact goal of therapy is unclear because different blood glucose targets were used in earlier studies (eg, 215 mg/dL in DIGAMI versus 110 mg/dL in the Belgian study of critically-ill patients). In the setting of AMI, it is prudent to avoid excessive hypoglycemia and, thus, more modest goals for blood glucose may be considered until more definitive data are present. Aggressive therapy with continuous infusion of insulin seems to improve a host of metabolic and physiologic effects that are associated with acute hyperglycemia and improves mortality in the acute setting. Aggressive glycemic control should be coupled with appropriate use of reperfusion therapies, glycoprotein IIb/IIa inhibitors, aspirin, 1-blockers, ACE inhibitors, and antithrombotic agents. The role of intensive chronic glucose control in reducing CV events is less clear but earlier studies were not well-powered; did not achieve aggressive, durable glycemic control; and did not use insulin-sensitizing agents routinely. Given the results of the DIGAMI trial, the goal of therapy postdischarge should include strict glycemic control while future studies help to delineate the role of insulin-sensitizing agents versus insulin-providing agents in reducing recurrent macrovascular events. Careful attention also should be paid to aggressive lifestyle modifications and treatment of hypertension, hyperlipidemia, and left ventricular dysfunction, as well as appropriate use of anti-platelet and antithrombotic agents.

Impact of stenting and abciximab in patients with diabetes mellitus undergoing primary angioplasty in acute myocardial infarction (the CADILLAC trial)

We sought to determine the benefits of stent implantation and abciximab in patients with diabetes mellitus and acute myocardial infarction (AMI) who underwent primary angioplasty. In a 2-by-2 factorial design, 2,082 patients with AMI were randomly assigned to balloon angioplasty versus stenting, with or without abciximab. Diabetes was present in 346 patients (16.6%). The primary end point was the composite incidence of death, disabling stroke, reinfarction, and ischemic target vessel revascularization (TVR). The primary end point at 1 year occurred significantly more frequently in diabetic than nondiabetic patients (21.9% vs 16.8%, p <0.02), driven by increased rates of death (6.1% vs 3.9%, p = 0.04) and TVR (16.4% vs 12.7%, p = 0.07). Among patients with diabetes, TVR at 1 year was significantly reduced with routine stenting compared with balloon angioplasty (10.3% vs 22.4%, p = 0.004), with no differences in death, reinfarction, or stroke. Angiographic restenosis was also greatly reduced in diabetics randomized to stenting (21.1% vs 47.6%, p = 0.009). No beneficial effects were apparent with abciximab in diabetic patients at 1 year. Despite the improved outcomes with stenting in patients with diabetes, 1-year mortality remained increased in diabetic patients who received stents compared with nondiabetics (8.2% vs 3.6%, p = 0.005). Thus, routine stent implantation in diabetic patients with AMI significantly reduces restenosis and enhances survival free from TVR, independent of abciximab use, although survival remains reduced compared with survival in nondiabetic patients regardless of reperfusion modality.

Ethnic variations in female vulnerability after an acute coronary event

OBJECTIVE

To determine the ethnic variation of short and long term female vulnerability after an acute coronary event in a population of Chinese, Indians, and Malays.

DESIGN

Population based registry.

PATIENTS

Residents of Singapore between the ages of 20-64 years with coronary events. Case identification and classification procedures were modified from the MONICA (monitoring trends and determinants in cardiovascular disease) project.

MAIN OUTCOME MEASURES

Adjusted 28 day case fatality and long term mortality.

RESULTS

From 1991 to 1999, there were 16 320 acute coronary events, including 3497 women. Age adjusted 28 day case fatality was greater in women (51.5% v 38.6%, p < 0.001), with a larger sex difference evident among younger Malay patients. This inequality between the sexes was observed in both the pre-hospitalisation and post-admission periods. Among hospitalised patients, women were older, were less likely to have suffered from a previous Q wave or anterior wall myocardial infarction, and had lower peak creatine kinase concentrations. Case fatality was higher among women, with adjusted hazard ratios of 1.64 (95% confidence interval (CI) 1.43 to 1.88) and 1.50 (95% CI 1.37 to 1.64) for 28 day and mean four year follow up periods. There were significant interactions of sex and age with ethnic group (p = 0.017). The adjusted hazards for mortality among Chinese, Indian, and Malay women versus men were 1.30, 1.71, and 1.96, respectively. The excess mortality among women diminished with age.

CONCLUSION

In this multiethnic population, both pre-hospitalisation and post-admission case fatality rates were substantially higher among women. The sex discrepancy in long term mortality was greatest among Malays and in the younger age groups.

Acute coronary syndromes and diabetes mellitus

Patients with diabetes mellitus who present with acute ST-segment elevation myocardial infarction or non-ST-segment elevation acute coronary syndromes have a higher risk of adverse outcomes than patients without diabetes, and appear to derive greater benefit from evidence-based therapies. However, patients with diabetes mellitus are less commonly treated with proven therapies, so renewed efforts are needed to improve the quality of care and outcomes for patients with diabetes mellitus who present with acute coronary syndromes.

Type 2 diabetes and intravenous thrombolysis outcome in the setting of ST elevation myocardial infarction

OBJECTIVE

There are conflicting results regarding the impact of type 2 diabetes on intravenous thrombolysis effectiveness during ST elevation myocardial infarction (STEMI). The present study, using a continuous 12-lead electrocardiogram, examined the possible association of type 2 diabetes with both acute intravenous thrombolysis effectiveness and long-term prognosis in this setting.

RESEARCH DESIGN AND METHODS

The study included 726 consecutive subjects (214 type 2 diabetic subjects) with STEMI who received intravenous thrombolysis in the first 6 h from index pain and were followed up for 3.5 years.

RESULTS

Type 2 diabetic subjects had significantly lower incidence of sustained > or = 50% ST recovery than nondiabetic subjects (P = 0.03). Additionally, the former required a significantly greater time interval through the achievement of this criterion than the latter (P < 0.001). In both type 2 diabetic (P < 0.001) and nondiabetic subjects (P < 0.001), those who had not attained > or = 50% ST recovery were at significantly higher risk of cardiac death than subjects who had reached this criterion. The subjects who attained the above electrocardiographic criterion in > or = 60 min after thrombolysis initiation were at significantly higher risk compared with those who achieved this criterion in <60 min (P = 0.02). However, this association was true only for type 2 diabetic subjects (P = 0.01) and not for nondiabetic subjects (P = 0.9).

CONCLUSIONS

The present study suggests that type 2 diabetes is a strong predictor of acute intravenous thrombolysis failure during STEMI. This finding may significantly contribute to the worse prognosis for type 2 diabetic subjects compared with nondiabetic ones in this setting.

Diabetes mellitus adversely affects the outcomes of thrombolytic therapy in patients with acute myocardial infarction

This study was performed to evaluate whether coexistent diabetes mellitus has any adverse effect on the outcomes of thrombolytic therapy in patients with acute myocardial infarction. Although the early reperfusion rates were similar between the two groups of patients who had acute myocardial infarction with and without diabetes mellitus (42% vs 45.4%, p > 0.05), the results of late angiographic examination showed a significantly lower rate of patency in infarct-related coronary artery (defined as TIMI 3 flow) in diabetics compared to nondiabetics (28.9% vs 41.3%, p < 0.001). The global left ventricular function was also poorer in diabetics (left ventricular wall motion score was 18.6 +/- 7.3 in diabetics and 14.1 +/- 4.6 in nondiabetics, p < 0.01).

Impaired chronotropic response to exercise in acute myocardial infarction patients with type 2 diabetes mellitus

This study was undertaken in acute myocardial infarction (AMI) patients with non-insulin-dependent diabetes mellitus (type 2 DM) to investigate their impaired chronotropic response to exercise. Seventy-one AMI subjects entered the study, 30 with type 2 DM and 41 age- and body mass index-matched non-DM (control) patients. One month after the onset of AMI, these patients underwent cardiopulmonary exercise testing on a treadmill under a ramp protocol. Anaerobic threshold (AT) and peak oxygen uptake (peak VO2) were determined as indicators of exercise capacity. Plasma norepinephrine (NE) concentration was measured in blood samples obtained at 2 time points: during pre-exercise rest and immediately after peak exercise. The change in NE concentration during exercise, as an index of sympathetic nervous activity, was calculated as a percentage: deltaNE = [(NE during exercise) - (resting value)]/(resting value) x 100. The change in heart rate (HR) during exercise was calculated as a simple difference: deltaHR = [(peak HR) - (rest HR)]. Index of chronotropic response to exercise was then quantified as the deltaHR/deltaNE during exercise. No significant intergroup differences in ejection fraction at rest or HR at peak exercise were observed. However, VO2 at AT, peak VO2, deltaHR, and deltaHR/deltaNE were significantly lower in the type 2 DM group than in the non-DM group. DeltaHR correlated with VO2 at AT (r = 0.49, P<0.001) and with peak VO2 (r = 0.53, P<0.001) in all subjects. Also, deltaHR/deltaNE correlated with VO2 at AT (r = 0.42, P<0.001) and with peak VO2 (r = 0.44, P<0.001) in all subjects. AMI patients with type 2 DM had impaired cardiopulmonary responses to maximal and submaximal exercise testing and impaired chronotropic response to exercise, even though their cardiac function at rest was similar to that of non-DM AMI patients. The data suggest that one mechanism of impaired cardiopulmonary response to exercise in AMI patients with type 2 DM groups is an impaired chronotropic response.

Pharmacotherapy of diabetes mellitus: implications for the prevention and treatment of cardiovascular disease

Diabetes mellitus in adults is associated with an increased risk of premature vascular disease and a higher mortality rate. The presence of other risk factors, often seen in diabetic patients, such as systemic hypertension, augments the rate of vascular diseases. Evidence is growing that tight control of hyperglycemia using insulin and/or oral hypoglycemic agents will modify this risk. More aggressive control of concomitant hypertension and/or hyperlipidemia is also required. Diabetic patients who have myocardial infarctions do worse than nondiabetic patients. Various strategies to improve outcomes include the use of tight blood glucose control, and various coronary interventions are currently under clinical study.

[Prevention and treatment of congestive heart failure in diabetic patients]

Diabetes mellitus is a strong risk factor for the development of cardiovascular disease, and is associated with a worse prognosis. The incidence of congestive heart failure is higher in diabetic patients, although the reasons for this increased rate are debated (higher incidence and severity of coronary heart disease and arterial hypertension, or a true diabetic cardiomyopathy). The treatment of heart failure in diabetic patients does not differ from that of non-diabetic patients, although recent studies of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers offer interesting new perspectives.

Short-term mortality of myocardial infarction patients with diabetes or hyperglycaemia during admission

AIM

The hypothesis that patients with hyperglycaemia during admission, regardless of previous diagnosis of diabetes, have worse prognosis than those with normal glucose values is controversial. The objective was to assess the role of hyperglycaemia on short-term mortality after myocardial infarction (MI).

METHODS AND RESULTS

A cohort study nested in a prospective registry of MI patients in the reference hospital of Gerona, Spain was performed. All consecutive MI patients under 75 were registered between 1993 and 1996. Patient and clinical characteristics, including previous diagnosis of diabetes, glycaemia on admission and in the next four days, were recorded. Patients with glycaemia on admission or four day mean glycaemia >6.67 mmol/l were considered hyperglycaemic. The main outcome measure was mortality at 28 days. Of 662 patients with MI included, 195 (29.7%) had previously known diabetes mellitus, but 457 (69.0%) had glycaemia >6.67 mmol/l on admission. Patients with hyperglycaemia on admission were older, more often female, more frequently had a previous diagnosis of diabetes, developed more complications, and had higher 28 day mortality. The effect of admission glycaemia >6.67 mmol/l on 28 day mortality was independent of major confounding factors, particularly previous diagnosis of diabetes (OR=4.20, 95% confidence intervals 1.18 to 14.96).

CONCLUSIONS

Higher 28 day mortality was observed among MI patients with glycaemia on admission >6.67 mmol/l compared with patients with lower levels, independently of major confounding variables and, particularly, previous diagnosis of diabetes. This early, simple, and inexpensive marker of bad prognosis after MI should prompt the application of more aggressive treatment of MI and risk factors and, probably, of glycaemia during admission.

Clinical outcomes of patients with diabetes mellitus and acute myocardial infarction treated with primary angioplasty or fibrinolysis

OBJECTIVE

To compare the early and late outcomes of primary percutaneous transluminal coronary angioplasty (PTCA) with fibrinolytic treatment among diabetic patients with acute myocardial infarction (AMI).

DESIGN

Retrospective observational study with data obtained from prospective registries.

SETTING

Tertiary cardiovascular institution with 24 hour acute interventional facilities.

PATIENTS

202 consecutive diabetic patients with AMI receiving reperfusion treatment within six hours of symptom onset.

INTERVENTIONS

Fibrinolytic treatment was administered to 99 patients, and 103 patients underwent primary PTCA. Most patients undergoing PTCA received adjunctive stenting (94.2%) and glycoprotein IIb/IIIa inhibition (63.1%).

MAIN OUTCOME MEASURES

Death, non-fatal reinfarction, and target vessel revascularisation at 30 days and one year were assessed.

RESULTS

Baseline characteristics were similar in these two treatment groups except that the proportion of patients with Killip class III or IV was considerably higher in those treated with PTCA (15.5% v 6.1%, p = 0.03) and time to treatment was significantly longer (103.7 v 68.0 minutes, p < 0.001). Among those treated with PTCA, the rates for in-hospital recurrent ischaemia (5.8% v 17.2%, p = 0.011) and target vessel revascularisation at one year (19.4% v 36.4%, p = 0.007) were lower. Death or reinfarction at one year was also reduced among those treated with PTCA (17.5% v 31.3%, p = 0.02), with an adjusted relative risk of 0.29 (95% confidence interval 0.15 to 0.57) compared with fibrinolysis.

CONCLUSION

Among diabetic patients with AMI, primary PTCA was associated with reduced early and late adverse events compared with fibrinolytic treatment.

Sulfonylureas are not associated with increased mortality in diabetics treated with thrombolysis for acute myocardial infarction

BACKGROUND

Sulfonylurea compounds may impair ischemic preconditioning and endogenous fibrinolysis. Increased mortality has been reported in diabetics receiving these drugs prior to admission for acute myocardial infarction when treated by direct angioplasty. Although thrombolytics are currently employed far more frequently than direct angioplasty the effect of sulfonylureas on mortality in the setting of thrombolysis has not been previously addressed.

METHODS

Two hundred forty five diabetics treated with either accelerated t-PA or streptokinase in a national, multi-center, randomized comparison of argatroban vs. heparin (n=1200) were grouped by anti-diabetic treatment prior to hospitalization, and their outcomes were compared by retrospective analysis.

RESULTS

Baseline characteristics were similar in all groups (sulfonylureas: n=121, oral medications other than sulfonylureas: n=17, insulin: n=28, diet alone: n=79). Sulfonylurea use was not associated with increased mortality or adverse event rates. By logistic regression analysis with diet treatment as reference, only prior insulin use was associated with higher risk for mortality at 30 days and 1 year (odds ratios 4.5 and 5.22, respectively, p<0.05).

CONCLUSIONS

Sulfonylureas use prior to admission is not associated with adverse outcomes in diabetics treated with thrombolytics for myocardial infarction. Since direct angioplasty may increase mortality in patients taking these drugs, a randomized trial is needed to specifically compare different strategies of acute reperfusion in diabetics.Abbreviated abstract. Increased mortality has been reported in diabetics using sulfonylureas when treated for myocardial infarction by direct angioplasty. No study has specifically addressed the effect of these drugs on outcomes in the setting of thrombolysis. In a retrospective analysis of 245 diabetics treated with thrombolysis in a randomized comparison of argatroban vs. heparin, outcomes were compared in relation to anti-diabetic therapy prior to admission. Sulfonylurea use did not adversely affect prognosis, which was worst among diabetics previously treated with insulin. In conclusion, sulfonylureas do not worsen outcomes of diabetics treated with current thrombolytic regimens in comparison with other anti-diabetic treatments.

[Diabetes mellitus, inflammation and coronary atherosclerosis: current and future perspectives]

Type 2 diabetes mellitus is a condition associated with an increased risk of coronary artery disease. This condition is currently reaching epidemic proportions in the Western world. Epidemiological studies have shown that insulin resistance and the constellation of metabolic alterations associated with type 2 diabetes mellitus such as dyslipidaemia, systemic hypertension, obesity and hypercoagulability, have an effect on the premature onset and severity of atherosclerosis. Albeit direct, the link between insulin resistance and atherogenesis is rather complex. It is likely that its complexity relates to the interaction between genes that predispose to insulin resistance and genes that independently regulate lipid metabolism, coagulation processes and biological responses of the arterial wall. The rapid development of molecular biology in recent years has resulted in a better understanding of the immune and inflammatory mechanisms that underlie insulin resistance and atherosclerosis. For example, it is known that nuclear transcription factors such as nuclear factor kappa beta and peroxisome proliferator-activated receptor are involved in atherosclerosis. The former modulates gene expression which encodes pro-inflammatory proteins vital for the development of the atheromatous plaque. In the presence of insulin resistance there are multiple activating factors that could explain the early onset and severity of atherosclerosis. Glitazones, the new oral antidiabetic drugs and agonists of peroxisome proliferator-activated receptor, have been shown to improve peripheral insulin sensitivity and to also delay atherosclerosis progression in experimental models. Their beneficial effects have been linked to their anti-inflammatory effect.