Silent myocardial ischemia and microalbuminuria in asymptomatic subjects with non-insulin-dependent diabetes mellitus

Effects of D-Chiro-Inositol on Glucose Metabolism in db/db Mice and the Associated Underlying Mechanisms

In this study, we observed the effect of D-chiro-inositol (DCI) on glucose consumption in type 2 diabetic db/db mice, and investigated the relevant mechanism. We discovered that the stability of 24-h blood glucose under the nonfasting condition and decreased glucose tolerance were both alleviated after treatment with DCI. Moreover, the content of glycosylated protein and advanced glycation end products in the serum was reduced, the damage in the liver tissue was alleviated, and the synthesis of liver glycogen was significantly promoted. In addition, DCI increased the expression of insulin receptor substrate 2 (IRS2), phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), glucose transporters 4 (GLUT4), and phospho-AKT (S473) protein. In contrast, DCI decreased the expression level of glycogen synthase kinase 3β (GSK3β) protein in liver tissue to various degrees, as shown by immunohistochemistry and western blotting. Furthermore, DCI increased the mRNA expression of IRS2, PI3K, AKT, and GLUT4, and reduced that of GSK3β in liver tissue, as demonstrated by polymerase chain reaction. Finally, DCI promoted glucose consumption in high glucose-stimulating HepG2 cells and increased the expression of IRS2 protein in HepG2 cells, as revealed by fluorescence staining and flow cytometry. Our results indicate that DCI can significantly improve glucose metabolism in diabetic mice and HepG2 cells. This effect may be associated with the upregulation of IRS2, PI3K, AKT, and GLUT4 and downregulation of GSK3β.

The First Harmonic of Radial Pulse as an Early Predictor of Silent Coronary Artery Disease and Adverse Cardiac Events in Type 2 Diabetic Patients

Background

It has been reported that harmonics of radial pulse is related to coronary artery disease (CAD) in patients with type 2 diabetes mellitus (T2DM). It is still unclear whether or not the first harmonics of the radial pulse spectrum is an early independent predictor of silent coronary artery disease (SCAD) and adverse cardiac events (ACE).

Objectives

To measure the risk of SCAD in patients with T2DM and also to survey whether or not an increment of the first harmonic (C1) of the radial pulse increases ACE.

Methods

1968 asymptomatic individuals with T2DM underwent radial pulse wave measurement. First harmonic of the radial pressure wave, C1, was calculated. Next, the new occurrence of ACE and the new symptoms and signs of coronary artery disease were recorded. The follow-up period lasted for 14.7 ± 3.5 months.

Results

Out of 1968 asymptomatic individuals with T2DM, ACE was detected in 239 (12%) of them during the follow-up period. The logrank test demonstrated that the cumulative incidence of ACE in patients with C1 above 0.96 was greater than that in those patients with C1 below 0.89 (P < 0.01). By comparing the data of patients with C1 smaller than the first quartile and the patients with C1 greater than the third quartile, the hazard ratios were listed as follows: ACE (hazard ratio, 2.29; 95% CI, 1.55–3.37), heart failure (hazard ratio, 2.22; 95% CI, 1.21–4.09), myocardial infarction (hazard ratio, 2.44; 95% CI, 1.51–3.93), left ventricular dysfunction (Hazard ratio, 2.01; 95% CI, 0.86–4.70), and new symptoms and signs for coronary artery disease (hazard ratio, 2.03; 95% CI, 1.45–2.84). As C1 increased, the risk for composite ACE (P < 0.001 for trend) and for coronary disease (P < 0.001 for trend) also increased. The hazard ratio and trend for cardiovascular-cause mortality were not significant.

Conclusions

This study showed that C1 of the radial pulse wave is correlated with cardiovascular events. Survival analysis showed that C1 value is an independent predictor of ACE and SCAD in asymptomatic patients with T2DM. Thus, screening for the first harmonic of the radial pulse may improve the risk stratification of cardiac events and SCAD in asymptomatic patients although they had no history of coronary artery disease or angina-related symptom.

Radial Pulse Spectrum Analysis as Risk Markers to Improve the Risk Stratification of Silent Myocardial Ischemia in Type 2 Diabetic Patients

Diabetic patients with silent myocardial ischemia (SMI) have elevated rates of morbidity and mortality and need intensive care and monitoring. An early predictor of SMI may lead to early diagnosis and medical treatment to prevent progression and adverse clinical events. Therefore, this paper was aimed to evaluate the radial pulse spectrum as risk markers to improve the risk stratification of SMI in type-2 diabetic patients; 195 diabetic patients at high-risk of SMI were enrolled. All patients underwent myocardial perfusion imaging and radial pressure wave measurement. The spectrum analysis of the radial pressure wave was calculated and transformed into Fourier series coefficients Cns and Pns. The risk of SMI (odds ratio: 4.46, 95%, C.I. 1.61–12.4, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.01$ \end{document}) was raised in diabetic patients classified high-risk group by C2. Multivariable regression analysis showed that C2 (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.05$ \end{document}) and ankle–brachial index [(ABI) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.05$ \end{document})] were related to SMI (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$R=0.46$ \end{document} and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.05$ \end{document}). The myocardial ischemic score (MIS), combining C2, C3, and P5, the albumin-to-creatinine ratio (ACR), and ABI, presented an excellent risk stratification performance in enrolled patients (odds ratio: 5.78, 95%, C.I. 2.29–14.6, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{upgreek} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} }{}$P<0.01$ \end{document}). The area under receiver operating characteristic curves for C2, C3, P5, ABI, ACR, and MIS were 0.66, 0.60, 0.68, 0.51, 0.56, and 0.74, respectively, in identifying SMI. This paper demonstrated that C2 was independently associated with the extent of SMI in multivariable regression analysis. Odds ratio and chi-square tests reflected that C2 could be an important marker for the risk stratification of SMI. Furthermore, MIS, adding radial pulse spectrum analysis to ACR and ABI, could significantly improve the risk stratification of SMI in type-2 diabetic patients compared to any single risk factor.

Residual Angina After Elective Percutaneous Coronary Intervention in Patients With Diabetes Mellitus

BACKGROUND

Previous studies suggest that among patients with stable coronary artery disease, patients with diabetes mellitus (DM) have less angina and more silent ischemia when compared with those without DM. However, the burden of angina in diabetic versus nondiabetic patients after elective percutaneous coronary intervention (PCI) has not been recently examined.

METHODS AND RESULTS

In a 10-site US PCI registry, we assessed angina before and at 1, 6, and 12 months after elective PCI with the Seattle Angina Questionnaire angina frequency score (range, 0-100, higher=better). We also examined the rates of antianginal medication prescriptions at discharge. A multivariable, repeated-measures Poisson model was used to examine the independent association of DM with angina over the year after treatment. Among 1080 elective PCI patients (mean age, 65 years; 74.7% men), 34.0% had DM. At baseline and at each follow-up, patients with DM had similar angina prevalence and severity as those without DM. Patients with DM were more commonly prescribed calcium channel blockers and long-acting nitrates at discharge (DM versus not: 27.9% versus 20.9% [P=0.01] and 32.8% versus 25.5% [P=0.01], respectively), whereas β-blockers and ranolazine were prescribed at similar rates. In the multivariable, repeated-measures model, the risk of angina was similar over the year after PCI in patients with versus without DM (relative risk, 1.04; range, 0.80-1.36).

CONCLUSIONS

Patients with stable coronary artery disease and DM exhibit a burden of angina that is at least as high as those without DM despite more antianginal prescriptions at discharge. These findings contradict the conventional teachings that patients with DM experience less angina because of silent ischemia.

Assessing Cardiovascular Risk and Testing in Type 2 Diabetes

PURPOSE OF REVIEW

Type 2 diabetes confers approximately twofold-increased risk for cardiovascular disease. Early risk stratification of these patients may help reduce cardiovascular events. This review discusses the state of the art of risk factors, biomarkers, and subclinical disease parameters potentially useful in cardiovascular risk assessment in type 2 diabetes.

RECENT FINDINGS

Scientific progress in the past decade has identified a spectrum of risk in diabetic individuals rather than categorizing diabetes as a coronary heart disease equivalent as previously done. Recent data on emerging biomarkers and diagnostic imaging, along with traditional risk factors, provide evidence to help inform individualized cardiovascular risk assessment. Comprehensive assessment of traditional risk factors, biomarkers, complications of diabetes, and subclinical atherosclerosis may help classify diabetic individuals as low, intermediate, or high risk for determining the intensity of lifestyle modification and pharmacotherapy. Further research may lead to a comprehensive pathway for cardiovascular disease risk assessment in diabetic patients.

Comparison of the hospital arrival time and differences in pain quality between diabetic and non-diabetic STEMI patients

The aim of our study was to determine whether diabetic ST segment elevation myocardial infarction (STEMI) patients arrive in the emergency room (ER) later than non-diabetics, compare the differences in pain quality and quantity between those groups, and measure differences in the outcome after an index hospitalization. A total of 266 patients with first presentation of STEMI were included in our study during a period of two years, 62 with diabetes and 204 without diabetes type 2. Pain intensity and quality at admission were measured using a McGill short form questionnaire. Diabetic patients did not arrive significantly later than non-diabetic (χ²; p = 0.105). Most diabetic patients described their pain as "slight" or "none" (χ²; p < 0.01), while most non-diabetic patients graded their pain as "moderate" or "severe" (χ²; p < 0.01). The quality of pain tended to be more distinct in non-diabetic patients, while diabetic patients reported mainly shortness of breath (χ²; p < 0.01). Diabetic patients were more likely to suffer a multi-vessel disease (χ²; p < 0.01), especially in the late arrival group. Therefore, cautious evaluation of diabetic patients and adequate education of target population could improve overall survival while well-organized care like a primary PCI Network program could significantly reduce CV mortality.

Microalbuminuria predicts silent myocardial ischaemia in type 2 diabetes patients

PURPOSE

Myocardial ischaemia is frequently silent in patients with type 2 diabetes. Although it has been proposed as a potential screening tool, the role of myocardial perfusion single photon emission computed tomography (MPS) has recently been questioned, due to the low prevalence of positive scans and the low rate of cardiac events. The aim of this study was to assess if pretest clinical variables can identify a subgroup of asymptomatic patients with type 2 diabetes at risk of silent myocardial ischaemia and a subsequent poor outcome

METHODS

This prospective study included 77 patients (50 men, mean age 63 ± 9 years) with type 2 diabetes and no known coronary artery disease (CAD) or angina pectoris who underwent gated MPS to screen for CAD between March 2006 and October 2008. MPS images were interpreted using a semiquantitative visual 20-segment model to define summed stress, rest and difference scores. Ischaemia was defined as a sum difference score (SDS) ≥2. Patients were followed-up (median 4.1 years, range 0.8 - 6.1 years) and cardiac hard events (cardiac death or nonfatal myocardial infarction) were recorded.

RESULTS

Silent ischaemia was detected in 25 of the 77 patients (32 %). Specifically, 10 patients (13 %) had mild ischaemia (SDS 2 to ≤4) and 15 patients (19 %) had severe ischaemia (SDS >4). In univariate binary logistic analysis, microalbuminuria was the only significant predictor of silent ischaemia on MPS (odds ratio 4.42, 95 % CI 1.27 - 15.40; P = 0.019). The overall accuracy of microalbuminuria for predicting silent ischaemia was 71.4 % and was 89.6 % for predicting severe ischaemia. Kaplan-Meier curves showed no significant group differences in 5-year cardiac event-free survival between patients with and those without microalbuminuria, or between patients with SDS ≥2 and those with SDS <2. In contrast, 5-year event-free survival was significantly lower in patients with SDS >4 than in patients with SDS ≤4: 55.6 % (95 % CI 39.0 - 72.2 %) vs. 94.5 % (95 % CI: 91.4 - 97.6 %), respectively (Breslow test, chi-square 20.9, P < 0.001). Median cardiac event-free survival was not observed in the whole group, while the 25th percentile of cardiac event-free survival was reached only in patients with SDS >4 (2.3 years). In univariate Cox regression analysis, SDS >4 predicted cardiac event-free survival (hazard ratio 12.87, 95 % CI 2.86 - 27.98; P = 0.001), while SDS ≥2 did not (hazard ratio 2.78, 95 % CI 0.62 - 12.46, P = 0.16).

CONCLUSION

In this group of patients with type 2 diabetes, microalbuminuria was the only predictor of silent ischaemia on MPS. Assessment of microalbuminuria should be routinely considered among the first risk stratification steps for CAD in patients with type 2 diabetes, even though severe ischaemia on MPS is a major predictor of cardiac event-free survival.

Osteoprotegerin, leptin and IL-6: association with silent myocardial ischemia in type 2 diabetes mellitus

BACKGROUND

Diabetic patients often exhibit severe, asymptomatic coronary artery disease (CAD). The relationship between osteoprotegerin (OPG), inflammatory markers and silent myocardial ischemia remains to be elucidated.

METHODS

We recruited 45 type 2 diabetic patients and 33 healthy controls and assessed them for silent myocardial ischemia (SMI) by myocardial perfusion imaging. Patient blood was tested for OPG, IL-6 and leptin concentrations.

RESULTS

OPG, leptin and IL-6 levels were found significantly elevated in diabetic patients (p < 0.001, p < 0.01, p < 0.05). Based on our classification of presence/absence of SMI in our diabetic group, we found that there was a significant association between SMI and the biomarkers IL-6 (p < 0.001), leptin (p < 0.001) and OPG (p < 0.05). In multivariate regression analyses, OPG was found to be significantly related to diabetes mellitus and to SMI. Age, sex and smoking increased the association between OPG and SMI.

CONCLUSION

High OPG, leptin and IL-6 levels are associated with the presence and severity of SMI in type 2 diabetic patients.

Clinical review: Screening for coronary artery disease in type 2 diabetes

CLINICAL CONTEXT

Sensitive tools are available to diagnose occult ischemic and atherosclerotic coronary disease, yet screening for coronary artery disease (CAD) has not been shown to reduce cardiac events in patients with type 2 diabetes mellitus (T2DM). Professional guidelines are inconsistent regarding CAD screening recommendations, but it is suggested that those at highest risk (10-yr risk ≥20%) for cardiac events may benefit.

EVIDENCE ACQUISITION

We reviewed bibliographies of professional CAD screening guidelines, review articles, and clinical trials published within the last 10 yr, although we have included relevant older studies. We excluded studies that did not focus on T2DM or explicitly analyze that subgroup.

EVIDENCE SYNTHESIS

Although screening for coronary ischemia or atherosclerosis does provide incremental prognostic information in patients with T2DM and previously undiagnosed CAD, this has not been found to significantly impact outcomes. This appears to result from comparable efficacy of revascularization and optimal medical therapy in stable CAD. Limited evidence supports the hypothesis that those with more severe CAD (three-vessel, left main, proximal left anterior descending) amenable to bypass surgery may be potential beneficiaries of screening. However, the low prevalence of such candidates in the asymptomatic population, continuing advances with percutaneous intervention, and the lack of prospective trials makes such a recommendation currently unsupportable.

CONCLUSIONS

Findings to date do not support widespread screening for CAD in patients with T2DM. A future strategy identifying those at highest risk as screening candidates may ultimately be effective, but the optimal method for selecting those subjects or subsequent treatment is unknown.

Impact of biomarkers for endothelial dysfunction and procoagulant state on 10-year cardiovascular risk in Type 2 diabetes

AIMS

To estimate the coronary heart disease and cardiovascular disease risk associated with novel biomarkers in Type 2 diabetes mellitus.

METHODS

We measured baseline peripheral blood concentrations of soluble E-selectin, factor XIIa, thrombin-antithrombin III complex and plasminogen activator inhibitor-1 in 86 patients with Type 2 diabetes free of known coronary heart disease. We used Cox proportional hazard models to estimate multivariable-adjusted hazard ratios associated with biomarker levels for 10-year coronary heart disease risk (n = 33 events) or total cardiovascular disease risk (n = 45 events).

RESULTS

At baseline, mean (sd) age was 62 years (7 years); 62 were men; and 43 had microalbuminuria. Soluble E-selectin demonstrated cross-sectional relationships with glucose and factor XIIa was related to plasminogen activator inhibitor-1 and triglycerides (all P < 0.05). Baseline log soluble E-selectin was significantly related to incident coronary heart disease and cardiovascular disease. Hazard ratios (95% CIs) associated with a 1-unit increase in log soluble E-selectin in age- and sex-adjusted models were: coronary heart disease : 4.6 (95% CI 1.9-11.3), P = 0.001; cardiovascular disease: 3.6 (95% CI 1.7-7.4, P = 0.001); and in multivariable-adjusted models were: coronary heart disease: 2.9 (95% CI 1.2-7.1, P = 0.02); cardiovascular disease: 2.3 (95% CI 1.1-4.8), P = 0.02. Factor XIIa was significantly related to incident cardiovascular disease. The hazard ratios associated with a 1-unit increase in factor XIIa in age- and sex-adjusted models was 1.5 (95% CI 1.1-1.9, P = 0.003) and in a multivariable-adjusted model was 1.3 (95% CI 1.0-1.6, P = 0.047). Plasminogen activator inhibitor-1 and thrombin-antithrombin III complex were not related to cardiovascular disease events.

CONCLUSIONS

In our study, soluble E-selectin and factor XIIa were significantly related to 10-year incident macrovascular events in patients with Type 2 diabetes. These preliminary findings call for replication in larger studies.

Assessment and treatment of cardiovascular risk in prediabetes: impaired glucose tolerance and impaired fasting glucose

Individuals with impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG) are at high risk, not only to develop diabetes mellitus, but also to experience an adverse cardiovascular (CV) event (myocardial infarction, stroke, CV death) later in life. The underlying pathophysiologic disturbances (insulin resistance and impaired β-cell function) responsible for the development of type 2 diabetes are maximally/near maximally expressed in subjects with IGT/IFG. These individuals with so-called prediabetes manifest all of the same CV risk factors (dysglycemia, dyslipidemia, hypertension, obesity, physical inactivity, insulin resistance, procoagulant state, endothelial dysfunction, inflammation) that place patients with type 2 diabetes at high risk for macrovascular complications. The treatment of these CV risk factors should follow the same guidelines established for patients with type 2 diabetes, and should be aggressively followed to reduce future CV events.

Incidence and predictors of silent myocardial infarction in type 2 diabetes and the effect of fenofibrate: an analysis from the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study

AIMS

To determine the incidence and predictors of, and effects of fenofibrate on silent myocardial infarction (MI) in a large contemporary cohort of patients with type 2 diabetes in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study.

METHODS AND RESULTS

Routine electrocardiograms taken throughout the study were assessed by Minnesota-code criteria for the presence of new Q-waves without clinical presentation and analysed with blinding to treatment allocation and clinical outcome. Of all MIs, 36.8% were silent. Being male, older age, longer diabetes duration, prior cardiovascular disease (CVD), neuropathy, higher HbA(1c), albuminuria, high serum creatinine, and insulin use all significantly predicted risk of clinical or silent MI. Fenofibrate reduced MI (clinical or silent) by 19% [hazard ratio (HR) 0.81, 95% confidence interval (CI) 0.69-0.94; P = 0.006], non-fatal clinical MI by 24% (P = 0.01), and silent MI by 16% (P = 0.16). Among those having silent MI, fenofibrate reduced subsequent clinical CVD events by 78% (HR 0.22, 95% CI 0.08-0.65; P = 0.003).

CONCLUSION

Silent and clinical MI have similar risk factors and increase the risk of future CVD events. Fenofibrate reduces the risk of a first MI and substantially reduces the risk of further clinical CVD events after silent MI, supporting its use in type 2 diabetes.

Pre-exercise cardiology screening guidelines for asymptomatic patients with diabetes

Coronary heart disease is a major cause of morbidity and mortality in persons with diabetes mellitus. Exercise is an important cornerstone in the treatment and management of diabetes but is also associated with a heightened risk of sudden cardiac death in those with occult coronary heart disease. Before beginning a physical activity program that involves anything greater than moderate intensity exercise, consideration should be given to screening asymptomatic persons with diabetes for silent myocardial ischemia.

Screening for coronary artery disease in patients with diabetes

Coronary artery disease (CAD) accounts for a large fraction of the morbidity, mortality, and cost of diabetes. Recognizing this, nearly 10 years ago the American Diabetes Association published a consensus recommendation that clinicians consider a risk factor-guided screening approach to early diagnosis of CAD in both symptomatic and asymptomatic patients. Subsequent clinical trial results have not supported those recommendations. Since the prior consensus statement, newer imaging methods, such as coronary artery calcium scoring and noninvasive angiography with computed tomography (CT) techniques, have come into use. These technologies, which allow quantitation of atherosclerotic burden and can predict risk of cardiac events, might provide an approach to more widespread coronary atherosclerosis screening. However, over this same time interval, there has been recognition of diabetes as a cardiovascular disease (CVD) equivalent, clear demonstration that medical interventions should provide primary and secondary CVD risk reduction in diabetic populations, and suggestive evidence that percutaneous coronary revascularization may not provide additive survival benefit to intensive medical management in patients with stable CAD. This additional evidence raises the question of whether documenting asymptomatic atherosclerosis or ischemia in people with diabetes is warranted. More data addressing this issue will be forthcoming from the BARI 2-D (Bypass Angioplasty Revascularization Investigation 2 Diabetes) trial. Until then, for patients with type 2 diabetes who are asymptomatic for CAD, we recommend that testing for atherosclerosis or ischemia, perhaps with cardiac CT as the initial test, be reserved for those in whom medical treatment goals cannot be met and for selected individuals in whom there is strong clinical suspicion of very-high-risk CAD. Better approaches to identify such individuals based on readily obtained clinical variables are sorely needed.

Reviewing myocardial silent ischemia: specific patient subgroups

Silent myocardial ischemia (SMI) is a relatively common, yet poorly understood, clinical entity. The most accurate means of detecting SMI and the precise treatment endpoints remain unclear. However, the presence of SMI correlates with the likelihood of future adverse cardiac events. Evidence suggests that patients at high risk of severe cardiac ischemia, even with the absence of symptoms, derive the greatest benefit from an aggressive diagnostic and therapeutic approach. This paper is giving a detailed review of SMI in regards to specific patient subgroups, i.e. populations with diabetes mellitus, hypertension, elderly patients, post-revascularization patients, women, the suggested screening procedures for each subgroup, as well as the emersion of new markers for the selection of high-risk patients for screening.

The changing costs and benefits of screening for asymptomatic coronary heart disease in patients with diabetes

Aggressive medical therapy can be justified in most patients with diabetes, but there may be some higher-risk asymptomatic patients who could benefit from revascularization and/or medical therapy for myocardial ischemia. Silent myocardial ischemia (SMI) might be used to identify these high-risk individuals. In this Review we define SMI as objective evidence of ischemia from any noninvasive test occurring in an asymptomatic patient. We outline what is known about asymptomatic coronary heart disease (CHD) in diabetes and how this relates to SMI. We examine how SMI predicts angiographic CHD and CHD events, and we describe the changing role of CHD screening as reflected by various guidelines. We identify the recent research suggesting that there may be substantial numbers of high-risk asymptomatic patients who have diabetes with undiagnosed CHD and who could benefit from more-active intervention; however, with the recent advances in medical therapy, and the uncertain benefits of screening, current guidelines strongly discourage this practice, except in limited clinical situations, such as before major surgery. Carefully conducted clinical trails using state-of-the-art investigations and therapy in well-characterized patients with diabetes are urgently required to inform physicians on when and how to intervene.

Prevalence of silent myocardial ischaemia in new-onset middle-aged Type 2 diabetic patients without other cardiovascular risk factors

AIMS

Coronary artery disease (CAD) is the leading cause of death in patients with Type 2 diabetes and is often asymptomatic. Silent myocardial ischaemia (SMI) is frequent in diabetic subjects and is responsible for a late diagnosis of CAD; its early detection is important. There are some data about the prevalence of SMI in Type 2 diabetic patients at high risk for cardiovascular disease, while no data are available in subjects at the onset of diabetes without other cardiovascular risk factors.

METHODS

We screened 274 consecutive patients (mean age 64.3 +/- 8.4 years, 66% male) at the time of diagnosis of Type 2 diabetes; we enrolled 111 subjects without other cardiovascular disease risk factors (dyslipidaemia, hypertension, peripheral vascular disease, retinopathy, microalbuminuria, history of heart disease) and with normal resting electrocardiogram (ECG). Participants performed a maximal ECG exercise protocol and, if positive, underwent coronary angiography.

RESULTS

The ECG exercise test was positive in 19 patients (17.1%); of those 14 (13%) had angiographic coronary disease (one with three-vessel disease, three with two vessels and 10 with one vessel involved). The positive predictive value of the exercise ECG for predicting angiographic coronary disease was 73%.

CONCLUSIONS

The prevalence of SMI was 17% and angiographic coronary disease was found in 13% of middle-aged subjects with new-onset Type 2 diabetes without other cardiovascular risk factors. This prevalence is similar to that observed in studies of subjects with long duration diabetes who have additional cardiovascular risk factors.

Myocardial perfusion imaging and cardiac events in a cohort of asymptomatic patients with diabetes living in southern France

AIMS

To assess the association between abnormal stress myocardial perfusion imaging (MPI) and cardiac events (CE) in asymptomatic patients with diabetes and with > or = 1 additional risk factor. Predictors of abnormal stress MPI were also evaluated.

METHODS

Four hundred and forty-seven consecutive patients who underwent stress MPI were prospectively followed for 2.1 [0.5-4.1] years for the subsequent occurrence of hard CE (myocardial infarction and sudden or coronary death) and soft CE (unstable angina and ischaemic heart failure requiring hospitalization). Re-vascularization procedures performed as a result of the screening protocol were not included in the analysis.

RESULTS

Follow-up was successful in 419 of 447 patients (94%), of whom 71 had abnormal MPI at baseline. Medical therapy was intensified in all subjects and especially in those with abnormal MPI. Twenty-three patients with abnormal MPI underwent a re-vascularization procedure. CEs occurred in 14 patients, including six of 71 patients (8.5%) with abnormal MPI and eight of 348 patients (2.3%) with normal MPI (P < 0.005). Only two patients developed a hard CE and 12 a soft CE. In multivariate analysis, abnormal MPI was the strongest predictor for CEs [odds ratio (OR) (95% CI) = 5.6 (1.7-18.5)]. Low-density lipoprotein cholesterol > or = 3.35 mmol/l [OR (95% CI) = 7.3; 1.5-34.7] and age > median [OR (95% CI) = 6.0 (1.2-28.6)] were additional independent predictors for CE. The independent predictors for abnormal MPI were male gender, plasma triglycerides > or = 1.70 mmol/l, creatinine clearance < 60 ml/min and HbA1c > 8%, with male gender the strongest [OR (95% CI) = 4.0 (1.8-8.8)].

CONCLUSIONS

Asymptomatic patients with diabetes in this study had a very low hard cardiac event rate over an intermediate period. This could be explained by the effects of intervention or by the low event rate in the background population. Randomized studies of cardiac heart disease screening are required in asymptomatic subjects with diabetes to determine the effectiveness of this intervention.

Identifying which patients with diabetes should be tested for the presence of coronary artery disease – The importance of baseline electrocardiogram and exercise testing

Numerous studies have reported that diabetic patients should not always be considered to be coronary artery disease (CAD)-equivalent as was previously suggested. Exercise testing is widely available at a relatively low cost, and even among patients in whom the diagnosis of CAD is highly probable on the basis of age, sex, description of chest pain and history of prior myocardial infarction, exercise testing is often a clinical requirement for risk or prognosis assessment to determine the need for possible coronary angiography or revascularization. Nevertheless, because of either the presence of atypical symptoms or the absence of symptoms often encountered, the screening approach may differ in patients with diabetes mellitus. Because CAD is the major cause of mortality in patients with diabetes, its early detection is important to improve medical interventions and outcomes. This is critical because the available evidence suggests that occult CAD is common among asymptomatic patients with diabetes. Therefore, noninvasive testing for asymptomatic CAD may be helpful for the identification of diabetic patients with severe coronary obstruction in whom revascularization therapy may be considered the first manifestation of silent CAD in patients with diabetes is a fatal cardiac event in approximately one-half of the patients. The present paper reviews some clinical markers that may be helpful to the clinician to increase the yield of finding significant occult CAD while screening patients with diabetes.

The association between left ventricle diastolic dysfunction and endothelial dysfunction and the results of stress myocardial SPECT in asymptomatic patients with type 2 diabetes

Diabetes mellitus is associated with a poor cardiovascular prognosis. Stress myocardial single-photon emission computed tomography (SPECT) reliably detects coronary ischaemia in asymptomatic patients. Our study aimed to evaluate the association between systolic and diastolic left ventricular function, left ventricular hypertrophy, endothelial function and the results of stress myocardial SPECT in 126 patients with type 2 diabetic patients with no cardiovascular symptoms. Thirty-three patients (26%) had abnormal SPECT results, 33 patients (26%) had intermediate (equivocal) results, and 60 patients (48%) had normal results. We found a significant association between an abnormal SPECT result, left ventricular diastolic dysfunction and impaired post-ischaemic dilatation of the brachial artery. No association was found between the SPECT result and systolic function and left ventricular hypertrophy, however. An abnormal SPECT result was significantly associated with left ventricular diastolic dysfunction and the deterioration of post-ischaemic dilatation of the brachial artery in asymptomatic patients with type 2 diabetes.

Diabetes mellitus: evaluation of patients with known or suspected coronary artery disease and the role played by myocardial perfusion imaging

Type 2 diabetes markedly increases cardiovascular risk, and patients often present with advanced and asymptomatic disease. The fact that diabetes is associated with an increased risk of acute coronary events and poor long-term survival makes a strong case for detecting coronary artery disease early, perhaps before clinical manifestation in this patient population. This article examines the role of myocardial perfusion scintigraphy in the diagnostic and prognostic evaluation of diabetic patients with suspected coronary artery disease and in screening high-risk asymptomatic diabetic patients.

Markers for silent myocardial ischemia in diabetes. Are they helpful?

Silent myocardial ischemia (SMI) and silent coronary stenoses (CS) are two to seven times more frequent in diabetic patients than in non-diabetic patients. In addition to this, they have a higher predictive value for cardiovascular events than the classical cardiovascular risk factors, either taken alone or combined. Coronary arterial disease is the leading cause of mortality and morbidity in the diabetic population. Altogether, these data suggest that screening for SMI and silent CS is an important issue. We assume that detecting SMI and silent CS improves patient management, and leads to optimised follow-up, action taken on nutrition, exercise and lifestyle, management of the cardiovascular risk factors, and revascularisation procedures whenever possible. However, screening for SMI and silent CS is expensive and may induce morbidity. Selecting the patients with a high a priori risk of SMI and silent CS is therefore of major concern. Carotid or lower limb peripheral arterial disease, proteinuria, male gender, an age greater than 60 years, and two or more cardiovascular risk factors among smoking, microalbuminuria, dyslipidemia, hypertension, a family history of premature cardiac disease, and cardiac autonomic neuropathy have been demonstrated to be the best current predictors of SMI and silent CS. New markers, such as adhesion molecules, Lp(a), inflammation parameters or homocysteine, and endothelium function assessment might be of further help in the future.

The role of non-invasive imaging in the risk stratification of asymptomatic diabetic subjects

AIMS

Coronary artery disease (CAD) is the leading cause of death in patients with diabetes. Patients often present with advanced and asymptomatic disease. Proposed strategies that may favourably affect CAD risk and outcomes in this patient population include identifying diabetic patients with subclinical disease at high risk of future cardiac events. The purpose of this article was to review the role of both atherosclerosis imaging tests (coronary calcium imaging and high-resolution ultrasound assessment of carotid intima-media thickness) and functional imaging techniques [stress echocardiography and radionuclide myocardial perfusion imaging (MPI)] in the diagnostic and prognostic evaluation of asymptomatic diabetic subjects.

METHODS AND RESULTS

We identified studies using MEDLINE searches (1966 to April 2005) and by reviewing reference lists. A comprehensive list of search terms was applied. All stress echocardiography and MPI studies evaluating the prevalence and/or prognostic value of myocardial ischaemia (n = 19) and coronary calcium imaging studies (n = 2) evaluating the prognostic value of subclinical atherosclerosis in diabetic patients were included.

CONCLUSION

Asymptomatic myocardial ischaemia can be detected in a significant proportion of diabetic subjects by non-invasive imaging tests such as MPI and stress echocardiography. The results of ongoing and future studies may be helpful in guiding the selection of asymptomatic diabetic subjects to undergo non-invasive imaging, establishing the cost-effectiveness of various testing strategies and their impact on prognosis.

Silent myocardial ischemia is associated with autonomic neuropathy and other cardiovascular risk factors in type 1 and type 2 diabetic subjects, especially in those with microalbuminuria

The prevalence of silent myocardial ischemia (SMI) seems to be above average in diabetic subjects. As routine screening is costly, identifying high-risk populations is mandatory. This study aimed to estimate the prevalence of SMI in diabetic subjects and in controls and to define the diabetic population at risk. We studied 353 asymptomatic caucasian subjects (217 with diabetes and 136 controls matched by age, sex, and cardiovascular risk factors) with normal resting ECG. The diabetic group included 39 type 1 and 178 type 2 diabetics (age 57 +/- 11 yr, 162 males/55 females). Subjects performed the Treadmill Test (TT) and, when abnormal, underwent single-photon emission computed tomography (SPECT) with exercise testing or dipyridamole injection. Coronary angiography was performed if the SPECT was suggestive of ischemia. TT was positive in 16 (8.5%) diabetics: 3 with type 1 and 13 with type 2. No controls had positive TT. SPECT was performed in 13 subjects and was positive in 10; angiography was performed in 7 and identified significant lesions in all cases. Patients with SMI were older and had a higher prevalence of autonomic neuropathy, hypertension, and dyslipidemia than those without. Microalbuminuria was also higher in the SMI group (613 +/- 211 vs 72 +/- 245 mg/d; p < 0.05). We conclude that diabetic patients aged over 60 with autonomic neuropathy and other cardiovascular risk factors should be screened for the presence of SMI especially if they have increased microalbuminuria.

Cost-effectiveness of screening for coronary artery disease in asymptomatic patients with Type 2 diabetes and additional atherogenic risk factors

OBJECTIVE

Screening for coronary artery disease (CAD) in asymptomatic diabetic patients with two additional atherogenic risk factors has been recommended by the American College of Cardiology/American Diabetes Association, but its cost-effectiveness is yet to be determined. The present study aims to evaluate the cost-effectiveness of screening and determine acceptable strategies.

DESIGN

Cost-effectiveness analysis using a Markov model was performed from a societal perspective to measure the clinical benefit and economic consequences of CAD screening in asymptomatic men with diabetes and two additional atherogenic risk factors. We evaluated cohorts of patients stratified by different age groups, and 10 possible combination pairs of atherogenic risks. Incremental cost-effectiveness of no screening, exercise electrocardiography, exercise echocardiography, or exercise single-photon emission-tomography (SPECT) was calculated. Input data were obtained from the published literature. Outcomes were expressed as U.S. dollars per quality-adjusted life-year (QALY).

MEASUREMENTS AND MAIN RESULTS

Compared with no screening, incremental cost-effectiveness ratio of exercise electrocardiography was $41,600/QALY in 60-year-old asymptomatic diabetic men with hypertension and smoking, but was weakly dominated by exercise echocardiography. Exercise echocardiography was most cost-effective, with an incremental cost-effectiveness ratio of $40,800/QALY. Exercise SPECT was dominated by other strategies. Sensitivity analyses found that results varied depending on age, combination of additional atherogenic risk factors, and diagnostic test performance.

CONCLUSIONS

Incremental cost-effectiveness ratio of CAD screening in asymptomatic patients with diabetes and two or more additional atherogenic risk factors is shown to be acceptable from a societal perspective. Exercise echocardiography was the most cost-effective strategy, followed by exercise electrocardiography.

The association of silent coronary artery disease and metabolic syndrome in Chinese with type 2 diabetes mellitus

OBJECTIVES

Cardiovascular diseases account for approximately 75% of the deaths that occur in patients with diabetes. Because the clinical signs of coronary artery disease (CAD) in diabetic patients are hard to detect and routine screening is costly, it would be of great benefit to try to either prevent CAD from occurring or to detect it early and provide optimal care. Therefore, we analyzed the risk factors that might predict CAD in type 2 diabetes mellitus (T2DM) patients with no classical cardiac ischemic symptoms.

METHODS

Using a resting 12-lead ECG, exercise treadmill test, or thallium myocardial scintigraphy with exercise testing and dipyridamole injection, we screened diabetic patients already enrolled in a disease management program for possible CAD. We used diagnostic coronary angiography to confirm its presence. The definition and criteria of metabolic syndrome we used were modified from those outlined by the WHO classification and criteria of NCEP-ATP III.

RESULTS

A total of 850 T2DM patients without clinical and electrocardiographic evidence of CAD were studied. Three hundred and sixty-eight asymptomatic patients with normal resting ECG were examined by exercise ECG test or thallium scintigraphy examination. Sixty patients considered to have a strong positive test or significant thallium myocardial ischemia received a diagnostic coronary angiography. Fifty-one were found to have significant coronary artery stenosis; 9 showed no significant ischemic lesion. While gender, patients' age, known diabetes duration, serum uric acid level, smoking status, and the presence of WHO-metabolic syndrome defined hypertension and nephropathy were associated with silent CAD, logistic regression analysis found that the only predictor of silent CAD was the presence of nephropathy. The components of NCEP-ATP III-metabolic syndrome were not found to be associated with silent CAD.

CONCLUSIONS

A considerable proportion of T2DM patients have silent CAD. A diabetic patient with incipient or overt nephropathy should be examined for the presence of CAD. The definition of metabolic syndrome may be modified for early detection of CAD in patients with T2DM.

Silent myocardial ischemia in diabetic and nondiabetic patients with coronary artery disease

BACKGROUND

Patients with diabetes mellitus are at increased risk for CAD; silent ischemia is reported to be frequent in diabetic populations. The aim of the present study was to evaluate the prevalence of silent ischemia in diabetic and nondiabetic patients with assessed CAD.

METHODS AND RESULTS

We recruited a total of 618 patients with CAD: 309 were consecutive diabetic patients and 309 were age- and gender-matched nondiabetic patients. Myocardial ischemia was evaluated both during daily life and during exercise testing. Angina pectoris during daily life was more frequent in diabetic than in nondiabetic patients (80% vs. 74%, P<0.05). The anginal pain intensity either during daily life or acute myocardial infarction (MI), the prevalence of a previous MI, the extent of CAD and ergometric parameters were similar in diabetics and nondiabetics. Silent ischemia during exercise was documented in 179 (58%) diabetics and in 197 (64%) nondiabetics (nonsignificant, ns). Both diabetics and nondiabetics with silent exertional myocardial ischemia differed from symptomatic subjects in higher heart rate values (P<0.01), systolic blood pressure (P<0.01), rate-pressure product (P<0.001), work load (P<0.01) and maximum ST-segment depression at peak exercise (P<0.05).

CONCLUSIONS

The incidence of silent myocardial ischemia during exercise was similar in diabetic and nondiabetic CAD patients. Surprisingly, diabetics showed a higher prevalence of angina pectoris during daily activity than nondiabetics. A significant association between the presence of symptoms during daily life and exercise was observed in both groups. Our results may contribute to the planning of the clinical management of diabetic CAD patients and confirm the individual attitude to pain of CAD patients independent of the presence of diabetes.

Prediction of cardiovascular risk in people with diabetes

People with diabetes are at high risk of cardiovascular morbidity and mortality, especially if they have already developed vascular problems. For patients who are apparently free of vascular complications, risk tables are often used to assess the risk of cardiovascular events in the following years, and to decide on treatment with statins or anti-platelet therapy. These risk prediction tables include estimates of traditional cardiovascular risk factors and are based on populations, some of which only contained a very small number of people with diabetes. Multiple problems can be identified with these tables, and many seriously underestimate cardiovascular risk in people with diabetes. Possible ways of addressing this include using risk estimation tools based solely on diabetic populations, adding in additional traditional variables such as triglycerides or left ventricular hypertrophy, including novel cardiovascular risk factors, or intervening at a lower level of estimated risk in people with diabetes compared with non-diabetic subjects. Alternatively, estimates of individual risk could be abandoned and all people with diabetes could be treated with statins and other effective agents.

Silent ischemia is more prevalent among hypertensive patients with microalbuminuria and salt sensitivity

Some patients with essential hypertension manifest greater than normal urinary albumin excretion (UAE). Salt-sensitive hypertensives also manifest greater UAE compared to salt-resistant individuals. Although the significance of these associations is not well established, several lines of evidence suggest that microalbuminuria and/or salt sensitivity may be associated with greater prevalence of cardiovascular risks and events. In this study, we have evaluated by ergometric exercise 42 subjects with microalbuminuria and 42 matched individuals with normal UAE. All these subjects also underwent a standardized protocol to determine blood pressure sensitivity to a high salt intake. Patients with microalbuminuria displayed greater levels of ambulatory blood pressure and a greater rise in systolic blood pressure during exercise compared to patients with normal UAE (33.1 +/- 1.56 vs 26.4 +/- 1.7 mmHg, P < 0.001). Seven hypertensive patients with microalbuminuria developed ST segment depression during exercise compared to only one subject with normal UAE. Salt-sensitive patients manifested greater UAE than salt-resistant subjects (58 and 14 mg, 24 h, P < 0.001) and greater prevalence of silent ischemia (6 vs 2) than salt-resistant individuals. In conclusion, these studies have shown that hypertensive individuals with microalbuminuria and/or salt sensitivity manifest an increased prevalence of silent ischemia.

Silent coronary artery disease in type 2 diabetes mellitus: the role of Lipoprotein(a), homocysteine and apo(a) polymorphism

BACKGROUND

There is little data on the relationship between novel cardiovascular risk factors and silent coronary artery disease (CAD) in diabetic patients. We investigated whether Lipoprotein(a), homocysteine and apolipoprotein(a) polymorphism are associated with angiographically assessed asymptomatic coronary artery disease (CAD) in diabetic patients.

METHODS

1,971 type 2 diabetic patients without clinical signs of cardiovascular diseases and with a negative history of CAD were consecutively evaluated. Among them, 179 patients showed electrocardiographic abnormalities suggestive of ischemia or previous asymptomatic myocardial infarction. These 179 patients were subjected to a non-invasive test for CAD (ECG stress testing and/or scintigraphy). Among patients with a highly positive stress testing (n = 19) or a positive scintigraphy (n = 74), 75 showed an angiographically documented CAD (CAD group). Seventy-five patients without CAD (NO CAD group) were matched by age, sex and duration of diabetes to CAD patients. In NO CAD patients an exercise ECG test, a 48-hour ambulatory ECG and a stress echocardiogram were negative for CAD.

RESULTS

Lipoprotein(a) levels (22.0 +/- 18.9 versus 16.0 +/- 19.4 mg/dl; p < 0.05), homocysteine levels (13.6 +/- 6.6 versus 11.4 +/- 4.9 mmol/l; p < 0.05) and the percentage of subjects with at least one small apolipoprotein(a) isoform (70.7% versus 29.3%; p < 0.0001) were higher in CAD than NO CAD group. Logistic regression analysis showed that apolipoprotein(a) polymorphism (OR:8.65; 95%CI:3.05-24.55), microalbuminuria (OR:6.16; 95%CI:2.21-17.18), smoking (OR:2.53; 95%CI:1.05-6.08), HDL (OR:3.16; 95%CI:1.28-7.81), homocysteine (OR:2.25; 95%CI:1.14-4.43) and Lipoprotein(a) (OR:2.62; 95%CI:1.01-6.79) were independent predictors of asymptomatic CAD.

CONCLUSIONS

The present investigation shows an independent association of Lipoprotein(a), homocysteine and apo(a) polymorphism with silent CAD. Other studies are needed to establish whether these parameters are suitable for CAD screening in diabetic patients.

Assessment of asymptomatic coronary artery disease in apparently uncomplicated type 2 diabetic patients: a role for lipoprotein(a) and apolipoprotein(a) polymorphism

OBJECTIVE

In patients with uncomplicated diabetes, there is low probability of finding significant coronary artery disease (CAD) by noninvasive tests. Therefore, screening for its presence is not justified, and it is important to find reliable predictors of silent CAD to identify patients with uncomplicated diabetes for further screening. The relationship between lipoprotein(a) [Lp(a)], apolipoprotein(a) [apo(a)] polymorphism, and silent CAD has never been studied. We investigated the association of Lp(a) and apo(a) polymorphism with angiographically documented asymptomatic CAD in type 2 diabetic patients without evident complications.

RESEARCH DESIGN AND METHODS

A total of 1,323 diabetic patients without any clinical and electrocardiographic evidence of CAD were evaluated. Of 121 patients with highly positive results of exercise electrocardiography (ECG) (n = 30) or positive results on exercise thallium scintigraphy (n = 91), 103 subjects showed angiographically documented CAD (CAD group). Of 1,106 patients with negative results on exercise ECG, 103 subjects without CAD (NO CAD group) were selected and matched by age, gender, and duration of diabetes to patients in the CAD group. In patients in the NO CAD group, results of exercise ECG, 48-h ambulatory ECG, and stress echocardiography were negative for CAD.

RESULTS

The CAD group had higher Lp(a) levels (21.7 +/- 17.7 vs. 15.2 +/- 19.0 mg/dl; P = 0.0093) than the NO CAD group, and a percentage of subjects had at least one small apo(a) isoform (68.9 vs. 29.1%; P = 0.0000) higher than the NO CAD group. Logistic regression analysis showed that apo(a) phenotypes (odds ratio [OR] 8.13, 95% CI 3.65-21.23), microalbuminuria (5.38, 2.44-11.88), smoking (2.72, 1.31-5.64), and Lp(a) levels (2.41, 1.15-5.03) were predictors of asymptomatic CAD.

CONCLUSIONS

Our investigation reports the first evidence of an independent association of Lp(a) and apo(a) polymorphism with asymptomatic CAD. This suggests that Lp(a) levels and apo(a) phenotypes could be used together with other risk factors as markers of asymptomatic CAD in patients with diabetes.

Significance of silent ischemia and microalbuminuria in predicting coronary events in asymptomatic patients with type 2 diabetes

OBJECTIVES

The aim of this study was to investigate the relationships between future coronary heart disease (CHD) events and baseline silent myocardial ischemia (SMI) and microalbuminuria (MA) in subjects with type 2 diabetes (T2D) free from known CHD.

BACKGROUND

Coronary heart disease is often asymptomatic in subjects with diabetes. There is limited information on the prognostic value of SMI and MA in this group.

METHODS

Eighty-six patients with T2D and no history of CHD were studied (43 with MA individually matched with 43 normoalbuminuric patients; mean [SD] age 62 [+/-7] years, 62 men). Metabolic assessment, three timed overnight urine collections for albumin excretion rate, a treadmill exercise test and ankle brachial index (ABI) were performed at baseline. Patients were followed for 2.8 years.

RESULTS

Forty-five (52%) patients had SMI during treadmill testing. At review, there had been 23 coronary (CHD) events in 15 patients. Univariate Cox regression analysis showed that CHD events were significantly related to baseline ABI (p = 0.014), SMI (p = 0.020), MA (p = 0.046), 10-year Framingham CHD risk >30% (p = 0.035) and fibrinogen (p = 0.026). In multivariate analysis, SMI was the strongest independent predictor of CHD events (p = 0.008); risk ratio (95% confidence interval) for SMI: 21 (2 to 204). In the prediction of CHD events, SMI showed higher sensitivity and positive predictive value than MA or Framingham calculated CHD risk.

CONCLUSIONS

The presence of baseline SMI and MA are associated with future CHD events in asymptomatic patients with T2D and may be of practical use in risk stratification.

Diagnosing coronary artery disease in diabetic patients

Although several diagnostic modalities are available to the clinician interested in diagnosing coronary artery disease, very few have been validated in diabetic populations. This review discusses the non-invasive diagnosis of coronary disease in diabetic patients. Evidence regarding the prevalence and prognostic significance of silent ischemia is reviewed and the potential impact of silent ischemia on the diagnostic characteristics of the exercise treadmill test discussed. Other diagnostic tools are considered, and recommendations are made with respect to screening asymptomatic diabetic patients for coronary artery disease.

Usefulness of diabetic retinopathy as a marker of risk for thallium myocardial perfusion defects in non-insulin-dependent diabetes mellitus

Among 236 non-insulin-dependent diabetics with clinically suspected coronary artery disease, the rate of thallium-201 myocardial perfusion defects was significantly higher in subjects with (40.6%) than without (22.1%) diabetic retinopathy. Retinopathy was associated with a higher risk of perfusion defects in subjects with cardiac and noncardiac chest pain, and may thus be a useful marker for selecting patients in whom thallium scintigraphy screening is warranted.

Inducible myocardial ischaemia in asymptomatic Type 2 diabetic patients

BACKGROUND

to define the prevalence of inducible myocardial ischaemia in asymptomatic Type 2 diabetic patients and its relation to urinary albumin excretion rate (AER).

METHODS

98 Type 2 diabetic patients aged 56+/-7 years, and 20 non-diabetic volunteers were recruited. Dypiridamole plus exercise thallium-201 myocardial single photon emission computed tomography (SPECT) was performed in all participants. Exclusion criteria were: age <30 or >70 years, evidence of cardiovascular disease, anomalous ECG, autonomic neuropathy or serum creatinine level >177 micromol/l.

RESULTS

36 out of 98 diabetic patients (37%) showed abnormal thallium SPECT (considered as inducible myocardial ischaemia), versus one out of 20 (5%) in control group (odds ratio 7.3 (95% CI 1.1-50.5), P<0.005). Among diabetic patients, prevalence of inducible ischaemia was greater in those with higher urinary AER (AER <30:30-300:> 300 mg/24 h: 26: 53: 88%, and greater in the normoalbuminuric group compared to the control group (26 vs. 5%; P<0.05). An AER >30 mg/24 h was the only independent factor associated with inducible myocardial ischaemia in the multivariate analysis (P=0.009).

CONCLUSIONS

raised urinary AER in asymptomatic diabetic patients is a risk factor for present myocardial ischaemia demonstrated by thallium dypiridamole tomography. The prevalence of inducible myocardial ischaemia in asymptomatic diabetic patients without known coronary disease is much higher than in non-diabetic population.

Increased left ventricular mass index and nocturnal systolic blood pressure in patients with Type 2 diabetes mellitus and microalbuminuria

AIMS

To compare left ventricular mass (LVM) index and function in patients with Type 2 diabetes mellitus with and without microalbuminuria and to investigate the clinical determinants of left ventricular hypertrophy.

METHODS

Echocardiography, electrocardiography and 24-h ambulatory blood pressure monitoring were performed in microalbuminuric (n = 29) and normoalbuminuric (n = 29) patients with Type 2 diabetes and no clinical evidence of heart disease. Groups were individually matched for age, sex and diabetes duration and smoking status.

RESULTS

LVM index (62 (34-87) vs. 52 (33-89) g/m2.7, P = 0.04) and LVH prevalence, using two out of three definitions, were greater in patients with microalbuminuria (LVM/height2.7: 72 vs. 59%, P = 0.27, LVM/height: 66 vs. 38%, P = 0.04, LVM/body surface area: 59 vs. 31%, P = 0.03). Night-time systolic blood pressure (126 (99-163) vs. 120 (104-157) mmHg, P = 0.005) and the night/day systolic blood pressure ratio (0.92 (0.08) vs. 0.88 (0.06), P = 0.04) were higher in those with microalbuminuria. Systolic and diastolic function were similar in both groups. Linear regression analyses showed that body mass index (BMI) was significantly related to loge LVM index (R2 = 11.8%, P = 0.005) and a relationship with night/day systolic blood pressure was also suggested (R2 = 4.6%, P = 0.057).

CONCLUSIONS

In patients with Type 2 diabetes, LVH is more common and severe in those with microalbuminuria. Its presence may be related to raised night/day systolic blood pressure ratio and is significantly related to BMI. The high prevalence of LVH strengthens the case for echocardiographic screening in Type 2 diabetes to identify high risk patients who might benefit from aggressive cardiovascular risk factor intervention.

High incidence of silent myocardial ischemia in elderly patients with non insulin-dependent diabetes mellitus

The present study was designed to reveal the incidence of silent myocardial ischemia in asymptomatic elderly non-insulin-dependent diabetic (NIDDM) patients (aged over 60 years). As a first step screening, maximal treadmill exercise test was performed. Of 140 patients studied, 54 (38.6%) were unable or not expected to achieve diagnostic levels of exercise during treadmill testing. A positive exercise test was noted in 39 of 86 (45.3%) subjects. As a second step examination, dipyridamole thallium scintigraphy was performed for 93 subjects who exhibited a positive exercise test and could not perform a maximal exercise test. Abnormal perfusion pattern was found in 39 of 93 (41.9%), who were finally considered to have a silent myocardial ischemia. Coronary angiography was performed in 18 subjects with diagnosis of silent myocardial ischemia, who gave their consent. Significant coronary artery stenosis was in fact found in 17 of 18 (94.4%) subjects studied, confirming a very high positive predictive value of this diagnostic procedure. In conclusion, elderly NIDDM patients (aged over 60 years) had an extremely high prevalence (estimated 26.3%) of silent myocardial ischemia. This evidence suggests that early and intensive detection may be needed as a part of routine care for this group.