Long-term clinical outcome in patients with acute coronary syndrome and dysglycaemia

Time-Dependent Risk for Recurrence in Survivors of Major Adverse Cardiovascular Events

INTRODUCTION

The prevalence of the population with a history of an occlusive cardiovascular event has been increasing in recent years, which means that a large number of patients will have a higher risk of presenting a fatal recurrence. The aim is to determine variables associated with time-to-recurrent cardiovascular events and analyze how changes in low-density lipoprotein cholesterol (LDL-C) levels during follow-up may be associated with this time-to-event.

MATERIALS AND METHODS

This is a prospective observational cohort study of 727 adults with a history of at least one occlusive cardiovascular event recruited at a referral hospital in northeastern Colombia. Data from a follow-up period of a maximum of 33 months (median 26 months) (one death) were used to define how clinical and sociodemographic variables impact the recurrence of major adverse cardiovascular events (MACE). Analyses were performed based on proportional hazard models and time-dependent hazard models.

RESULTS

Upon enrollment, 215 (30%) of the participants reported experiencing their most recent cardiovascular event within the preceding year. After two years, the recurrence rate was 12.38% (90/727). The risk of recurrence before two years was 3.9% (95% CI 2.7-5.6). In the multiple models, the presence of severe depression gives a Hazard Ratio of 8.25 (95% CI 2.98-22.86) and LDL ≥120 md/dl Hazard Ratio of 2.12 (95% CI 1.2 -3.9). It was found that LDL >120 mg/dl maintained over time increases the chances of recurrence by 1.7% (Hazard Ratio: 1.017, 95% CI 0.008-0.025).

CONCLUSIONS

The present study allows us to identify a profile of patients who should be treated promptly in an interdisciplinary manner to avoid recurrences of coronary events.

Exercise training after myocardial infarction increases survival but does not prevent adverse left ventricle remodeling and dysfunction in high-fat diet fed mice

AIMS

Aerobic exercise is an important component of rehabilitation after cardiovascular injuries including myocardial infarction (MI). In human studies, the beneficial effects of exercise after an MI are blunted in patients who are obese or glucose intolerant. Here, we investigated the effects of exercise on MI-induced cardiac dysfunction and remodeling in mice chronically fed a high-fat diet (HFD).

MAIN METHODS

C57Bl/6 male mice were fed either a standard (Chow; 21% kcal/fat) or HFD (60% kcal/fat) for 36 weeks. After 24 weeks of diet, the HFD mice were randomly subjected to an MI (MI) or a sham surgery (Sham). Following the MI or sham surgery, a subset of mice were subjected to treadmill exercise.

KEY FINDINGS

HFD resulted in obesity and glucose intolerance, and this was not altered by exercise or MI. MI resulted in decreased ejection fraction, increased left ventricle mass, increased end systolic and diastolic diameters, increased cardiac fibrosis, and increased expression of genes involved in cardiac hypertrophy and heart failure in the MI-Sed and MI-Exe mice. Exercise prevented HFD-induced cardiac fibrosis in Sham mice (Sham-Exe) but not in MI-Exe mice. Exercise did, however, reduce post-MI mortality.

SIGNIFICANCE

These data indicate that exercise significantly increased survival after MI in a model of diet-induced obesity independent of effects on cardiac function. These data have important translational ramifications because they demonstrate that environmental interventions, including diet, need to be carefully evaluated and taken into consideration to support the effects of exercise in the cardiac rehabilitation of patients who are obese.

Newly diagnosed diabetes based on an oral glucose tolerance test predicts cardiovascular outcomes in patients with coronary artery disease: An observational study

Diabetes is prevalent in patients with coronary artery disease (CAD). Using the oral glucose tolerance test (OGTT), abnormal glucose regulation can be detected early in CAD patients without known diabetes. In the present study, we assessed the impact of abnormal glucose regulation on the long-term cardiovascular outcomes of patients with established CAD. Patients hospitalized for a scheduled angiography due to angina were enrolled in Taichung Veterans General Hospital. Fasting plasma glucose (FPG) and 2-hour postload glucose (2hPG) were assessed using the OGTT. Hemoglobin A1c (HbA1c) and other biochemical analyses were assessed using fasting blood samples. During a median follow-up period of 4.6 years, a composite of all-cause mortality, nonfatal myocardial infarction, and nonfatal stroke was recorded as the primary endpoint. In 682 enrolled patients who completed the follow-up, there were 16 myocardial infarction events, 12 stroke events, and 58 deaths as composite endpoints. According to FPG and 2hPG, patients with newly diagnosed diabetes had a 2-fold higher risk for the composite endpoint than those in the normal glucose group (hazard ratio [HR], 2.011; 95% confidence interval (CI), 1.101-3.673; P = .023); however, prediabetes was not significantly associated with the composite endpoint (HR, 1.452; 95% CI, 0.788-2.675; P = .232). On the other hand, patients with diabetes diagnosed by FPG and HbA1c did not have a significantly higher risk for the composite endpoint than those in the normal glucose group (HR, 1.321; 95% CI, 0.686-2.545; P = .405). A 2hPG ≥7.8 mmol/L was a significant predictor for the composite endpoint (odds ratio, 1.743; 95% CI, 1.060-2.863; P = .028) after adjusting for age, sex, and estimated glomerular filtration rate. Diabetes, but not prediabetes, detected via OGTT is associated with a significantly increased risk for the composite endpoint in patients with established CAD. The 2hPG provided a greater predictive power for the composite endpoint than fasting glucose and HbA1c.

Atherogenic index of plasma for non-diabetic, coronary artery disease patients after percutaneous coronary intervention: a prospective study of the long-term outcomes in China

Background

Non-diabetic coronary artery disease (CAD) patients are thought to encounter metabolic dysfunction and while these changes may be imperceptible to the patient they probably influence outcomes. At present, there is no system to support patients sensing these subtle changes, nor is there an established model for prognoses. The Atherogenic Index of Plasma (AIP) index has already proven useful for atherosclerosis although further research is needed, especially for those without hyperglycemia.

Methods

This is a prospective study of 5538 non-diabetic CAD patients who had received percutaneous coronary intervention (PCI). Participants were assigned to one of three groups according to their AIP index. High AIP index cases were then compared to low index patients according to major adverse cardiac events (MACE). Restricted cubic spline (RCS) analysis was also conducted to investigate interrelations between AIP index levels and hazard ratios (HR) for MACEs.

Results

Patients with a high AIP index encountered metabolic dysfunction compared to those with a low AIP index i.e., higher Body Mass Index (BMI), Total Cholesterol (TC), Triglycerides (TG), and uric acid as well as lower HDL-C. Each of the aforementioned interrelations were significant with p values of less than 0.001. There was also a significant increase in the number of MACEs in the high AIP index group compared to the low AIP index group (HR: 1.37, 95% CI 1.04–1.81; p = 0.025). A J-shaped RCS curve highlighted a change in the HR after the 0.18 juncture (HR per SD: 1.20, 95% CI 0.96–1.50). Further subgroup analysis supported the main findings, all with HRs greater than one.

Conclusion

The AIP index could be used in prognostics for non-diabetic CAD patients 2 years after PCI. The relationship between hazard ratio and the AIP index appears to be J-shaped. Although, further multi-center studies designed for non-diabetic patients with potential metabolic dysfunction should be conducted to determine the value of the AIP index.

Admission Glucose Levels and Associated Risk for Heart Failure After Myocardial Infarction in Patients Without Diabetes

Background

Dysglycemia at acute myocardial infarction (AMI) is common and is associated with mortality. Information on other outcomes is less well explored in patients without diabetes in a long‐term perspective. We aimed to explore the relationship between admission glucose level and long‐term outcomes in patients with AMI without diabetes in a nationwide setting.

Methods and Results

Patients without diabetes (n=45 468) with AMI registered in SWEDEHEART (Swedish Web–System for Enhancement and Development of Evidence‐Based Care in Heart Disease Evaluated According to Recommended Therapies) and admission glucose ≤11 mmol/L (≤198 mg/dL) were followed for outcomes (AMI, heart failure, stroke, renal failure, and death) between 2012 and 2017 (mean follow‐up time 3.3±1.7 years). The association between categorized glucose levels and outcomes was assessed in adjusted Cox proportional hazards regression analyses (glucose levels 4.0–6.0 mmol/L [72–109 mg/dL] as reference). Further nonfatal complications and their associated mortality were explored (patients without events served as a reference). A glucose level of 7.8–11.0 mmol/L (140–198 mg/dL) was associated with hospitalization for heart failure (hazard ratio [HR] 1.40 [95% CI, 1.30–1.51], P<0.001), renal failure (1.17; 1.04–1.33, P=0.009), and death (1.31; 1.20–1.43, P<0.001), but not with recurrent myocardial infarction (0.99; 0.92–1.07, P=0.849) or stroke (1.03; 0.88–1.19, P=0.742). Renal failure had the strongest association with future mortality (age‐adjusted HR 4.93 [95% CI, 4.34–5.60], P<0.001), followed by heart failure (3.71; 3.41–4.04, P<0.001), stroke (3.39; 2.94–3.91, P<0.001), and myocardial infarction (2.08; 1.88–2.30, P<0.001).

Conclusions

Elevated glucose levels at AMI admission identifies patients without diabetes at increased risk of long‐term complications: in particular, hospitalization for heart and renal failure. These results emphasize that glucose levels at admission could be useful in risk assessment after myocardial infarction.

Predicting Long-Term Mortality in Patients with Angina across the Spectrum of Dysglycemia: A Machine Learning Approach

We aimed to develop and validate a model for predicting mortality in patients with angina across the spectrum of dysglycemia. A total of 1479 patients admitted for coronary angiography due to angina were enrolled. All-cause mortality served as the primary endpoint. The models were validated with five-fold cross validation to predict long-term mortality. The features selected by least absolute shrinkage and selection operator (LASSO) were age, heart rate, plasma glucose levels at 30 min and 120 min during an oral glucose tolerance test (OGTT), the use of angiotensin II receptor blockers, the use of diuretics, and smoking history. This best performing model was built using a random survival forest with selected features. It had a good discriminative ability (Harrell’s C-index: 0.829) and acceptable calibration (Brier score: 0.08) for predicting long-term mortality. Among patients with obstructive coronary artery disease confirmed by angiography, our model outperformed the Global Registry of Acute Coronary Events discharge score for mortality prediction (Harrell’s C-index: 0.829 vs. 0.739, p < 0.001). In conclusion, we developed a machine learning model to predict long-term mortality among patients with angina. With the integration of OGTT, the model could help to identify a high risk of mortality across the spectrum of dysglycemia.

Effects of exenatide on microvascular reactivity in patients with type 2 diabetes and coronary artery disease: A randomized controlled study

OBJECTIVE

We studied the effect of the GLP-1RA exenatide on skin microvascular function in patients with T2DM and CAD.

METHODS

Thirty-five patients with T2DM, CAD, and HbA1C 42-86 mmol/mol were randomized to treatment with exenatide or conventional non-GLP-1-based therapy for 12 weeks. Skin microvascular function was examined in the forearm by LDF and iontophoretic application of acetyl choline and SNP, and by PORH at baseline and after 12 weeks. Blood samples for fasting plasma glucose, HbA1C, and lipid profile were collected.

RESULTS

At 12 weeks, patients on exenatide showed reductions in HbA1C (from 63.5 ± 13 to 60.7 ± 14 mmol/mol, p = .065), body weight (from 92.6 ± 16 to 89 ± 16 kg, p < .001), and systolic blood pressure (from 141 ± 13 to 134 ± 16 mm Hg, p < .05) as compared to the conventionally treated group. There were no significant changes in skin microvascular function between or within the two groups at follow-up.

CONCLUSIONS

Three months' daily treatment with the GLP-1RA exenatide in T2DM patients with CAD showed no significant effects on skin microvascular function or blood glucose control, while this study confirms a reduction in body weight and blood pressure by exenatide, as compared to conventional antidiabetic drug treatment.

Prognostic impact of the atherogenic index of plasma in type 2 diabetes mellitus patients with acute coronary syndrome undergoing percutaneous coronary intervention

Background

The association of the atherogenic index of plasma (AIP), an emerging lipid index that can predict the risk for cardiovascular disease, with adverse outcomes in type 2 diabetes mellitus (T2DM) patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) has not been determined. Therefore, the aim of this study was to investigate whether the AIP could independently predict adverse cardiovascular events in T2DM patients with ACS undergoing PCI.

Methods

This study was a retrospective analysis of a single-centre prospective registry involving 826 consecutive T2DM patients who underwent primary or elective PCI for ACS from June 2016 to November 2017. This study ultimately included 798 patients (age, 61 ± 10 years; male, 72.7%). The AIP was calculated as the base 10 logarithm of the ratio of the plasma concentration of triglycerides to high-density lipoprotein-cholesterol (HDL-C). All the patients were divided into 4 groups based on the AIP quartiles. The primary endpoint was a composite of death from any cause, non-fatal spontaneous myocardial infarction (MI), non-fatal ischaemic stroke, and unplanned repeat revascularization. The key secondary endpoint was a composite of cardiovascular death, non-fatal MI, and non-fatal ischaemic stroke.

Results

During a median follow-up period of 927 days, 198 patients developed at least one event. An unadjusted Kaplan-Meier analysis showed that the incidence of the primary endpoint increased gradually with rising AIP quartiles (log-rank test, P = 0.001). A multivariate Cox proportional hazards analysis revealed that compared with the lowest AIP quartile, the top AIP quartile was associated with significantly increased risk for the primary and key secondary endpoints (hazard ratio [HR]: 2.249, 95% confidence interval [CI]: 1.438 to 3.517, P < 0.001; and HR: 2.571, 95% CI: 1.027 to 6.440, P = 0.044, respectively).

Conclusions

A higher AIP value on admission was independently and strongly associated with adverse cardiovascular events in T2DM patients with ACS undergoing PCI.

Diabetes mellitus, revascularization and outcomes in elderly patients with myocardial infarction-related cardiogenic shock

Background

The prognostic role of diabetes mellitus (DM) in elderly patients with myocardial infarction-related cardiogenic shock (MI-CS) remains controversial. Little information exists about the impact of intensive cardiac care unit (ICCU) and revascularization on outcomes of elderly patients with MI-CS. We aimed to assess the prognostic impact of DM according to age in patients with MI-CS, and to analyze the impact ICCU management and revascularization on in-hospital mortality in MI-CS patients at older ages.

Methods

Discharge episodes with diagnosis of CS associated with MI were selected from the Spanish National Health System's Basic Data Set. Centers were classified according to their availability of ICCU. Main outcome measured was in-hospital mortality.

Results

A total of 23, 590 episodes of MI-CS were identified, of whom 12, 447 (52.8%) were in patients aged ≥ 75 years. The impact of DM on in-hospital mortality was different among age subgroups. While in younger patients, DM was associated to a higher mortality risk (0.52 vs. 0.47, OR = 1.12, 95% CI: 1.06-1.18, χ² < 0.001), this association became non-significant in older patients (0.76 vs. 0.81, χ² = 0.09). Adjusted mortality rate of MI-CS aged ≥ 75 years was lower in patients admitted to hospitals with ICCU (adjusted mortality rate: 74.2% vs. 77.7%, P < 0.001) and in patients undergoing revascularization (74.9% vs. 77.3%, P < 0.001).

Conclusions

Prognostic impact of DM in patients with MI-CS was different according to age, with a significantly lower impact at older ages. The availability of ICCU and revascularization were associated with better outcomes in these complex patients.

Newly Discovered Abnormal Glucose Tolerance in Patients With Acute Myocardial Infarction and Cardiovascular Outcomes: A Meta-analysis

BACKGROUND

The prevalence of unrecognized abnormal glucose tolerance (AGT) and the incidence of recurrent cardiovascular (CV) events in patients with acute myocardial infarction (MI) has not been systematically evaluated.

PURPOSE

The purposes of this study were to define the prevalence of newly discovered AGT and examine the risk of recurrent major adverse cardiac events (MACE) and mortality in patients with acute MI.

DATA SOURCES

Medline, Embase, Cochrane Library, and Google Scholar were searched for relevant articles.

STUDY SELECTION

Inclusion criteria included prospective studies in patients with acute MI without known history of diabetes; AGT diagnosed using fasting plasma glucose, 2-h oral glucose tolerance test, or HbA_1c; and incidence of MACE and/or all-cause mortality in newly discovered AGT.

DATA EXTRACTION

Two investigators extracted the data. Pooled prevalence, incidence rate ratios, and hazard ratios (HRs) were calculated using random-effects models.

DATA SYNTHESIS

In 19 studies (n = 41,509, median follow-up 3.1 years), prevalence of newly discovered AGT was 48.4% (95% CI 40.2-56.6). Prediabetes had a higher mortality risk than normal glucose tolerance (NGT) (HR 1.36 [95% CI 1.13-1.63], P < 0.001) and MACE (1.42 [1.20-1.68], P < 0.001). Newly diagnosed diabetes had higher mortality risk than NGT (1.74 [1.48-2.05], P < 0.001) and MACE (1.54 [1.23-1.93], P < 0.001).

LIMITATIONS

This is not a meta-analysis of individual patient data. Time-to-event analysis and covariate-adjusted analysis cannot be conducted to examine heterogeneity reliably. Few studies reported CV death and heart failure hospitalizations.

CONCLUSIONS

Patients with acute MI have a high prevalence of newly discovered AGT. Aggressive risk reduction strategies in this population, especially in those with prediabetes, are warranted.

A potent risk model for predicting new-onset acute coronary syndrome in patients with type 2 diabetes mellitus in Northwest China

AIMS

Type 2 diabetes mellitus (T2DM) is now very prevalent in China. Due to the lower rate of controlled diabetes in China compared to that in developed countries, there is a higher incidence of serious cardiovascular complications, especially acute coronary syndrome (ACS). The aim of this study was to establish a potent risk predictive model in the economically disadvantaged northwest region of China, which could predict the probability of new-onset ACS in patients with T2DM.

METHODS

Of 456 patients with T2DM admitted to the First Affiliated Hospital of Xi'an Jiaotong University from January 2018 to January 2019 and included in this study, 270 had no ACS, while 186 had newly diagnosed ACS. Overall, 32 demographic characteristics and serum biomarkers of the study patients were analysed. The least absolute shrinkage and selection operator regression was used to select variables, while the multivariate logistic regression was used to establish the predictive model that was presented using a nomogram. The area under the receiver operating characteristics curve (AUC) was used to evaluate the discriminatory capacity of the model. A calibration plot and Hosmer-Lemeshow test were used for the calibration of the predictive model, while the decision curve analysis (DCA) was used to evaluate its clinical validity.

RESULTS

After random sampling, 319 and 137 T2DM patients were included in the training and validation sets, respectively. The predictive model included age, body mass index, diabetes duration, systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol, serum uric acid, lipoprotein(a), hypertension history and alcohol drinking status as predictors. The AUC of the predictive model and that of the internal validation set was 0.830 [95% confidence interval (CI) 0.786-0.874] and 0.827 (95% CI 0.756-0.899), respectively. The predictive model showed very good fitting degree, and DCA demonstrated a clinically effective predictive model.

CONCLUSIONS

A potent risk predictive model was established, which is of great value for the secondary prevention of diabetes. Weight loss, lowering of SBP and blood uric acid levels and appropriate control for DBP may significantly reduce the risk of new-onset ACS in T2DM patients in Northwest China.

Relationship between the frequency of nursing activities and adverse outcomes in patients with acute coronary syndrome: A retrospective cohort study

The aim of this retrospective cohort study was to identify the relationship between the frequency of nursing activities during the first hospitalization and adverse outcomes in patients with acute coronary syndrome by using electronic health records. Patients diagnosed with acute coronary syndrome from April 2010 to April 2015 were examined for eligibility based on 36 months of major adverse cardiac events as the main outcome. Among the 652 patients who were enrolled, 66 patients experienced major adverse cardiac events. The average frequency of nursing activities was 1098.7 (±2703.8), and four variables (length of hospital stay, albumin level, hemoglobin level, and frequency of nursing activities) were significantly associated with 36 months of major adverse cardiac events. After adjusting for these variables, the frequency of nursing activities was found to be the only significant factor associated with the incidence of 36 months of major adverse cardiac events. This finding suggests that patients with acute coronary syndrome who require more frequent nursing activities during the first hospitalization could be vulnerable to adverse outcomes and should be closely monitored.

The prognostic effect of known and newly detected type 2 diabetes in patients with acute coronary syndrome

BACKGROUND

Dysglycemia is a well-established risk factor of coronary artery disease. Less is known of the prognostic effect of dysglycemia in acute coronary syndromes (ACSs). The aim of this study was to evaluate the long-term outcome of patients with ACSs according to glucometabolic categories.

METHODS

Patients with ACSs were consecutively included in the study. Among those with no previous history of type 2 diabetes (T2DM) glucose metabolism was evaluated with fasting glucose in plasma, glycated hemoglobin and a standard 2-h oral glucose tolerance test. Patients were classified having normal glucose metabolism, prediabetes, newly detected T2DM (nT2DM) and previously known T2DM (kT2DM). The clinical outcome parameters were death or myocardial infarction and other major adverse cardiac events (MACEs).

RESULTS

A total of 372 ACS patients (male 75.8%, 65.1 years (SD: 11.8)) constituted the study population. The proportion diagnosed with normal glucose metabolism, prediabetes, nT2DM and kT2DM was 20.7%, 46.5%, 6.2% and 26.6%, respectively. The mean follow-up period was 2.9 years. Patients with prediabetes, nT2DM and kT2DM had a hazard ratio of 5.8 (95% confidence interval (CI) 0.8-44.6), 10.9 (95% CI 1.2-98.3) and 14.9 (95% CI 2.0-113.7), respectively, for death/myocardial infarction and 1.4 (95% CI 0.6-3.1), 2.9 (95% CI 1.1-8.0) and 3.3 (95% CI 1.5-7.6), respectively, for a composite of MACEs.

CONCLUSION

Patients with ACS and nT2DM or kT2DM were at increased risk of death/myocardial infarction and MACE compared with patients with normal glucose metabolism after approximately three years of follow-up.

Significance of prediabetes as a nosological entity

Prediabetes is a glucose metabolism disorder considered as a distinct nosological entity which strongly predicts the development of type 2 diabetes mellitus. This nosological entity itself is a serious condition indicating an increased risk of atherosclerotic and oncological complications. In patients with prediabetes, other components of metabolic syndrome are usually present, such as arterial hypertension, obesity or dyslipidaemia, further increasing an individual's risk of morbidity and mortality. Prediabetes is a long-developing disorder which offers enough time for early diagnosis and intervention; it may even be reversible. This review summarizes current knowledge on the definition, detection, epidemiology, cardiovascular and other consequences of prediabetes. It also gives suggestions for future research, along with recommendations for clinical practice.

Relative hyperglycemia is associated with complications following an acute myocardial infarction: a post-hoc analysis of HI-5 data

Background

Hyperglycemia is associated with increased morbidity and mortality in patients with an acute myocardial infarction (AMI). We evaluated whether complications after AMI are associated with absolute or relative glycemia.

Methods

A total of 192 patients with AMI were randomized to intensive or conventional insulin therapy. Absolute glycemia was defined as mean blood glucose level (BGL) during the first 24 h following randomization. Relative glycemia was defined by the stress hyperglycaemia ratio (SHR), calculated as mean BGL divided by average glucose concentration over the prior 3 months estimated from glycosylated haemoglobin. The primary endpoint was a “complicated AMI”, defined as an AMI complicated by death, congestive cardiac failure, arrhythmia, cardiac arrest, reinfarction, cardiogenic shock, inotrope use or emergency revascularization.

Results

There was not a significant association between mean BGL and complicated AMI (odds ratio (OR) 1.05 per mmol/L glucose increment, 95% confidence intervals (CI) 0.93–1.19). In contrast, SHR was positively associated with a complicated myocardial infarction (OR 1.22 per 0.1 SHR increment, 95% CI 1.06–1.42), and individual complications of death (OR 1.55, 95% CI 1.14–2.11), congestive cardiac failure (OR 1.27, 95% CI 1.05–1.54), arrhythmia (OR 1.31, 95% CI 1.12–1.54) and cardiogenic shock (OR 1.42, 95% CI 1.03–1.97). The relationship between SHR and a complicated AMI was independent of diabetic status, intensive insulin therapy, sex and hypoglycemia.

Conclusions

Relative, but not absolute, glycemia during insulin treatment is independently associated with complications after an AMI. Future studies should investigate whether basing therapeutic glycaemic targets on relative glycemia improves patient outcomes.

Beneficial effects of exercise training in heart failure are lost in male diabetic rats

Exercise training has been demonstrated to have beneficial effects in patients with heart failure (HF) or diabetes. However, it is unknown whether diabetic patients with HF will benefit from exercise training. Male Wistar rats were fed either a standard (Sham, n = 53) or high-fat, high-sucrose diet ( n = 66) for 6 mo. After 2 mo of diet, the rats were already diabetic. Rats were then randomly subjected to either myocardial infarction by coronary artery ligation (MI) or sham operation. Two months later, heart failure was documented by echocardiography and animals were randomly subjected to exercise training with treadmill for an additional 8 wk or remained sedentary. At the end, rats were euthanized and tissues were assayed by RT-PCR, immunoblotting, spectrophotometry, and immunohistology. MI induced a similar decrease in ejection fraction in diabetic and lean animals but a higher premature mortality in the diabetic group. Exercise for 8 wk resulted in a higher working power developed by MI animals with diabetes and improved glycaemia but not ejection fraction or pathological phenotype. In contrast, exercise improved the ejection fraction and increased adaptive hypertrophy after MI in the lean group. Trained diabetic rats with MI were nevertheless able to develop cardiomyocyte hypertrophy but without angiogenic responses. Exercise improved stress markers and cardiac energy metabolism in lean but not diabetic-MI rats. Hence, following HF, the benefits of exercise training on cardiac function are blunted in diabetic animals. In conclusion, exercise training only improved the myocardial profile of infarcted lean rats fed the standard diet. NEW & NOTEWORTHY Exercise training is beneficial in patients with heart failure (HF) or diabetes. However, less is known of the possible benefit of exercise training for HF patients with diabetes. Using a rat model where both diabetes and MI had been induced, we showed that 2 mo after MI, 8 wk of exercise training failed to improve cardiac function and metabolism in diabetic animals in contrast to lean animals.

HbA1c screening for new onset diabetes following acute coronary syndrome: is it a worthwhile test in clinical practice?

Background

Diabetes and pre-diabetes are prevalent in acute coronary syndrome (ACS) and relate to adverse outcomes. This study used HbA_1c to screen for degrees of glucose intolerance amongst patients without known diabetes presenting with ACS.

Methods

Over a 1-year period (June 2014–2015) consecutive patients admitted to a single centre cardiology unit with an initial diagnosis of ACS without prior diabetes diagnosis were electronically referred to our diabetes team. Patients were screened for the presence of diabetes by use of an initial HbA_1c blood test on day 2 or 3 post admission. If abnormal (≥42 mmol/mol; ≥6.0%), patients were invited for a repeat HbA_1c at 2 weeks, and if an intermediate result (42–47 mmol/mol; 6.0–6.4%), for an oral glucose tolerance test (OGTT) at 3 months. Patients were diagnosed with Type 2 diabetes if the repeat HbA_1c result was high (≥48 mmol/mol; ≥6.5%) or the OGTT at 3 months confirmed the diagnosis. Other data collected included baseline demographics, risk factors and any history of cardiovascular disease. All patients with ACS were stratified according to the diagnosis and subsequent management.

Results

We screened 399 patients in total. The mean age was 65 ± 14 years, 268 (67%) were men, 290 (73%) were Caucasian, 95 (24%) were South Asian and 14 (4%) were Afro-Caribbean ethnicity. Of all patients, 57 (14.3%) were diagnosed as pre-diabetes and 43 (10.8%) newly diagnosed diabetes. During the study 28 (7%) patients could not be classified; 6 (1.5%) patients died during the study and 22 (5.5%) patients were missing either initial or repeat HbA_1c and were subsequently lost to follow up. Of the baseline variables assessed, there were significantly more patients of South Asian ethnicity in the diabetes group compared to the normal group (42 vs 20%; p = 0.003). There was no difference in detection rates in patients with more severe ACS requiring percutaneous or cardiac surgical intervention.

Conclusions

The use of a simple HbA_1c screening method in clinical practice can detect new onset diabetes in approximately 1 in 10 high-risk post ACS patients.

Plaque Characteristics in Coronary Artery Disease Patients with Impaired Glucose Tolerance

BACKGROUND

Impaired glucose tolerance (IGT) patients are known to have a high risk of cardiovascular events and their prognosis has been reported to be poor. The present study aimed to compare coronary plaque characteristics among coronary artery disease (CAD) patients with normal glucose tolerance (NGT), those with IGT, and those with diabetes mellitus (DM) by using optical coherence tomography (OCT).

METHODS

The present study included 101 coronary artery disease patients (mean age, 67.9 ± 10.4 years; 82.4% male). OCT was performed for target and non-target vessels during percutaneous coronary intervention. The patients were divided into the following 3 groups: the NGT, IGT, and DM groups.

RESULTS

A total of 136 non-target residual plaques were found in 101 patients (27, 30, and 44 in the NGT, IGT, and DM groups, respectively). The size of the lipid core expressed as the mean angle of the lipid arc was significantly greater in the IGT and DM groups than in the NGT group (163.0 ± 58.7°, 170.1 ± 59.3°, and 130.9 ± 37.7°, respectively, P < 0.05). The fibrous cap covering the lipid core was significantly thinner in the IGT group than in the NGT group (77.0 ± 23.4 μm vs. 105.6 ± 47.0 μm, P = 0.040).

CONCLUSION

The coronary plaques in CAD patients are more vulnerable when having IGT compared to those with NGT, and similar to those with DM. This finding may explain the high risk of cardiovascular events in CAD patients with IGT.

Severely impaired microvascular reactivity in diabetic patients with an acute coronary syndrome

Background

Microvascular function is impaired in patients with stable coronary artery disease. The aim was to study microvascular function in patients with diabetes and acute coronary syndrome (ACS).

Methods

Microvascular function was evaluated in 83 patients by laser Doppler fluxmetry (LDF) [PU; perfusion unit, median (interquartile range)] measuring resting LDF and peak LDF following a six min heating of the skin to 44 °C at the foot, respectively. All patients with ACS and without previously known diabetes underwent oral glucose tolerance test. Thirty-nine patients with type 2 diabetes mellitus free from coronary artery disease served as controls.

Results

Peak LDF was significantly (P = 0.03) lower in patients with ACS and diabetes (n = 22; 72 (52)) and diabetes without coronary artery disease (n = 39; 69 (51)) as compared to patients with ACS without diabetes (n = 46; 97 (60)), and patients without ACS (n = 15; 140 (121)), respectively. Patients with ACS (n = 68) had significantly (P = 0.04) lower peak LDF (92 (49)) as compared to patients without ACS (n = 15) (140 (121)).

Conclusion

Microvascular reactivity is severely impaired in patients with diabetes and ACS. Diabetes has a major influence on microvascular function in patients with coronary artery disease.