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

Atherogenic dyslipidemia and risk of silent coronary artery disease in asymptomatic patients with type 2 diabetes: a cross-sectional study

Background

To investigate whether atherogenic dyslipidemia, a dyslipidemic profile combining elevated triglycerides and low high-density lipoprotein (HDL) cholesterol, is predictive of risk of silent myocardial ischemia (SMI) or angiographic coronary artery disease (CAD) in asymptomatic patients with type 2 diabetes.

Methods

Cohort study in 1080 asymptomatic patients with type 2 diabetes with a normal resting electrocardiogram, at least one additional cardiovascular risk factor and low density lipoprotein (LDL) cholesterol <3.35 mmol/L. Patients initially underwent screening for SMI by stress myocardial scintigraphy. Patients with SMI underwent coronary angiography.

Results

Overall, 60 (5.5 %) patients had atherogenic dyslipidemia (triglycerides ≥2.26 mmol/L and HDL cholesterol ≤0.88 mmol/L). In multivariate analyses taking into account the parameters associated in univariate analyses with SMI and then CAD, atherogenic dyslipidemia was associated with SMI (odds ratio 1.8[1.0–3.3]), as were male gender (OR 2.1[1.5–2.9]), BMI (OR 0.97[0.94–0.997]), retinopathy (OR 1.4[1.1–1.9]), peripheral occlusive arterial disease (POAD: OR 2.5[1.6–3.8]) and mean blood pressure (OR 1.01[1.00–1.03]); atherogenic dyslipidemia was associated with CAD (OR 4.0[1.7–9.2]), as were male gender (OR 3.0[1.6–5.6]), BMI (OR 0.94[0.90–0.995]), retinopathy (OR 1.7[1.0–2.9], POAD (OR 4.0[2.1–7.4]) and mean blood pressure (OR 1.03[1.01–1.05]). In the subgroup of 584 patients with LDL cholesterol <2.6 mmol/L, atherogenic dyslipidemia was also associated with CAD (OR 3.6[1.5–9.0]).

Conclusions

Atherogenic dyslipidemia was associated with an increased risk of SMI and silent CAD in patients with type 2 diabetes and LDL cholesterol levels <3.35 mmol/L. Specific management of atherogenic dyslipidemia might help reducing the high residual burden of cardiovascular disease.

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.

Association between Low-Molecular Weight Apolipoprotein(a) Isoforms and Obesity in Italian Women

OBJECTIVE

Low-molecular weight (MW) apolipoprotein(a) [apo(a)] isoforms are closely associated with an increased incidence of atherothrombotic disease, prevalence of which is higher in obese individuals, particularly in women. The hypothesis of this study was to assess whether there are differences in the distribution of apo(a) phenotypes between obese patients and healthy controls.

RESEARCH METHODS AND PROCEDURES

One hundred three obese Italian women (BMI > or = 30.0 kg/m2) were enrolled in the study, and apo(a) phenotyping was performed in all subjects. The prevalence of low-MW apo(a) isoforms, detected in plasma samples of our obese women, was compared with that found in a control group of 84 normal-weight, never-obese (BMI < 25.0 kg/m(2)), age-matched women.

RESULTS

The distribution of apo(a) isoforms in the population of obese women was significantly different from that found in normal-weight female subjects. In particular, the percentage of subjects in the obese group with at least one apo(a) isoform of low MW was significantly higher than that in the control group (51.4% vs. 32.1%, p = 0.0079).

DISCUSSION

Our results seem to suggest the possibility that small-sized apo(a) isoforms may be used together with other traditional risk factors to better assess the overall predisposition to atherothrombotic disease in obese women.

Lipoprotein(a) and homocysteine as genetic risk factors for vascular and neuropathic diabetic foot in type 2 diabetes mellitus

Neuropathy and peripheral artery disease represent the main pathophysiological conditions underlying diabetic foot. Several studies showed that Lipoprotein(a)-Lp(a)-and homocysteine (Hcy) can be associated with diabetic complications, but their relationship with diabetic foot is unclear. Aim of this study was to investigate whether Lp(a) and Hcy were associated with diabetic foot ulcerations, classified according to the presence of peripheral artery disease (PAD) or neuropathy. From among consecutive type 2 diabetic attending at the Diabetic Foot Clinic 27 subjects with vascular diabetic foot (VDF), 43 with neuropathic diabetic foot (NDF) and 52 controls without foot ulceration, neuropathy, and PAD were enrolled. Both Lp(a) (26.1 ± 22.7 vs. 14.9 ± 19.5 mg/dl; P = 0.003) and Hcy levels (15.4 ± 5.7 vs. 12.2 ± 5.1 μmol/l; P = 0.022) were significantly greater in the VDF group than in controls. Lp(a) levels were significantly lower in the NDF group than in controls (6.9 ± 8.1 versus 14.9 ± 19.5 mg/dl; P = 0.009), while no difference in Hcy levels was found. Multiple logistic regression analysis showed that Hcy was associated with VDF (OR: 1.11; 95% CI: 1.07-14.1; P = 0.048). Lp(a) did not enter the model, but its P-value was very near to the significant level (OR: 1.09; 95% CI: 0.99-12.05; P = 0.059). Moreover, low Lp(a) levels were associated with NDF (OR: 0.84; 95% CI: 0.21-0.96; P = 0.039). Our study has shown for the first time that high Lp(a) and Hcy levels are associated with the development of VDF, while low Lp(a) levels appear to be associated with delayed wound healing in patients with neuropathic foot ulcerations.

[Study of cardiovascular risk factors in Tunisian patients with recent type 2 diabetes]

OBJECTIVE

To study the frequency of silent myocardial ischemia (SMI) in Tunisian patients with recent type 2 diabetes and identify cardiovascular risk factors directly in relation with SMI.

PATIENTS AND METHODS

One hundred and twenty diabetics and sixty healthy people have benefited from blood sampling, electrocardiogram and exercise test.

RESULTS

The frequency of SMI was 21% in diabetics and 3% in healthy people (P=0.01). Obesity and hypertension were higher in diabetics than in healthy people (P=0.001 and P<10(-4)). Using unvaried analysis for risk factors with the presence of SMI in diabetics, we found that age greater than 60 yrs, male sex, sedentary and smoking were significantly correlated with SMI; respectively P=0.004, 0.01, 0.009 and 0.03. The SMI was found in 37% of diabetics with high blood pressure vs 8% in diabetics with normal blood pressure and was correlated with hypertriglyceridemia, hypoHDLemia and microalbuminuria. Patients with SMI had at least two cardiovascular risk factors apart from diabetes among those: age greater or equal to 60 yrs, male sex, smoking, hypertension, dyslipidemia and family history of early coronaropathy. Chronic inflammation and hyperhomocysteinemia were significantly correlated to SMI; OR=4.2 and 3.8. In addition, SMI was found in one diabetic over three who had bad glycemic control. Using multivariate analysis, only age greater or equal to 60 yrs, smoking, hypertension, hyperhomocysteinemia and hypertriglyceridemia were risk factors directly in relation with SMI in type 2 diabetes.

CONCLUSION

The assessment of global cardiovascular risk from the moment of discovering type 2 diabetes and the early screening of SMI should be necessary.

Erectile dysfunction can improve the effectiveness of the current guidelines for the screening for asymptomatic coronary artery disease in diabetes

About 40% of diabetic patients with asymptomatic coronary artery disease (CAD) are missed on the basis of the current screening guidelines. Erectile Dysfunction (ED) is a powerful marker of asymptomatic CAD. Aim of the study is to evaluate whether ED can improve the effectiveness of the current guidelines for the screening of CAD in diabetes. From among 299 consecutive men with newly diagnosed type 2 diabetes without any apparent vascular complication, 293 (mean age 56.6±5.9 years) were enrolled. Among them, 219 did not have myocardial ischemia (NO CAD group) and 74 men had a coronary stenosis angiographically proven (CAD group). Five risk factors (RFs) of the current screening guidelines (hypertension, dyslipidemia, family history for CAD, smoking e micro/macroalbuminuria) and ED were assessed. ED was significantly more prevalent in the CAD than in the NO CAD group (37.8 versus 15.1%; P<0.001) and was a predictor of asymptomatic CAD (OR: 4.4; 95%CI: 2.1-9.0; P<0.001). If ED is added to the list of RFs, it can increase the sensitivity of the current guidelines from 62 to 89%, without a significant variation in specificity (from 60 to 57%). The negative predictive value can increase from 82 to 94%. ED can reduce from 37.84 to 10.81% the percentage of patients with silent CAD missed at the screening. This study first shows that ED can improve the effectiveness in discriminating diabetic men to screen for asymptomatic CAD, when it is added to the list of RFs of the current screening guidelines.

Screening asymptomatic patients with type 2 diabetes mellitus for coronary artery disease: does it improve patient outcome?

The increasing global burden, the reported high prevalence of rapidly progressive coronary artery disease (CAD), and the atypical nature of CAD presentation in type 2 diabetes mellitus have encouraged development of strategies for detecting occult CAD in this population. Several recent prospective studies have addressed the value of screening for CAD in asymptomatic diabetic patients. The overall message of these studies is that despite detection of silent ischemia in a notable proportion of these patients, the dynamic nature of myocardial ischemia, the prohibitive cost of screening all asymptomatic patients, and the proven efficacy of primary preventive strategies would mandate implementation of better clinical risk stratification strategies for identifying at-risk individuals. Questions still remain as to what best strategy would allow proper patient selection through logical stepwise approaches to screening and whether that would alter patients' outcome when added to rigorously implemented primary preventive measures.

Detection of silent myocardial ischemia in asymptomatic patients with diabetes: results of a randomized trial and meta-analysis assessing the effectiveness of systematic screening

BACKGROUND

Most guidelines recommend a systematic screening of asymptomatic high risk patients with diabetes for silent ischemia, but the clinical benefit of this strategy has not been demonstrated compared with the simple control of cardiovascular risk factors. We sought to determine whether referring asymptomatic diabetic patients for screening of silent ischemia decreases the risk of cardiovascular events compared with usual care.

METHODS

DYNAMIT was a prospective, randomized, open, blinded end-point multicenter trial run between 2000 and 2005, with a 3.5 year mean follow-up in ambulatory care in 45 French hospitals. The study included 631 male and female with diabetes aged 63.9 ± 5.1 years, with no evidence of coronary artery disease and at least 2 additional cardiovascular risk factors, receiving appropriate medical treatment. The patients were randomized centrally to either screening for silent ischemia using a bicycle exercise test or Dipyridamole Single Photon Emission Computed Tomography (N = 316), or follow-up without screening (N = 315). The main study end point was time to death from all causes, non-fatal myocardial infarction, non-fatal stroke, or heart failure requiring hospitalization or emergency service intervention. The results of a meta-analysis of DYNAMIT and DIAD, a similar study, are also presented.

RESULTS

The study was discontinued prematurely because of difficulties in recruitment and a lower-than expected event rate. Follow-up was complete for 98.9% patients regarding mortality and for 97.5% regarding the main study end point. Silent ischemia detection procedure was positive or uncertain in 68 (21.5%) patients of the screening group. There was no significant difference between the screening and the usual care group for the main outcome (hazard ratio = 1.00 95%CI 0.59 to 1.71). The meta-analysis of these and DIAD results gave similar results, with narrower confidence intervals for each endpoint.

CONCLUSIONS

These results suggest that the systematic detection of silent ischemia in high-risk asymptomatic patients with diabetes is unlikely to provide any major benefit on hard outcomes in patients whose cardiovascular risk is controlled by an optimal medical treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00627783.

Lipoprotein a: where are we now?

PURPOSE OF REVIEW

To provide an update of the literature describing the link between lipoprotein a and vascular disease.

RECENT FINDINGS

There is evidence that elevated plasma lipoprotein a levels are associated with coronary heart disease, stroke and other manifestations of atherosclerosis. Several mechanisms may be implicated, including proinflammatory actions and impaired fibrinolysis.

SUMMARY

Lipoprotein a potentially represents a useful tool for risk stratification in the primary and secondary prevention setting. However, there are still unresolved methodological issues regarding the measurement of lipoprotein a levels. Targeting lipoprotein a in order to reduce vascular risk is hampered by the lack of well tolerated and effective pharmacological interventions. Moreover, it has not yet been established whether such a reduction will result in fewer vascular events. The risk attributed to lipoprotein a may be reduced by aggressively tackling other vascular risk factors, such as low-density lipoprotein cholesterol.

Myocardial perfusion scintigraphy in asymptomatic diabetic patients: a critical review

The increasing prevalence of diabetes mellitus and the associated high cardiovascular risk has made the non-invasive identification of silent coronary heart disease in diabetic individuals an important issue. This strategy could identify higher risk asymptomatic patients with diabetes mellitus in whom coronary revascularization may improve the outcome beyond that achieved by currently recommended medical management. Stress myocardial perfusion imaging has been shown to be effective in detecting coronary heart disease and predicting adverse cardiac events in asymptomatic diabetic patients. However, the clinical utility of myocardial perfusion scintigraphy is debated intensively due to the paucity of prospective and outcome based evidence. The controversy stems from several observational studies, epidemiologic data and cost-effectiveness analyses. Thus, although several authors and professional organizations advocate the use of stress imaging for screening higher risk asymptomatic diabetic patients, others are cautious in recommending any kind of stress testing in that population. This review is based on a broad survey of the literature and discusses the potential role of stress myocardial perfusion scintigraphy in screening asymptomatic diabetic subjects for coronary heart disease in the current era and in relation with other non-invasive screening tools.

Identification of asymptomatic type 2 diabetes mellitus patients with a low, intermediate and high risk of ischaemic heart disease: is there an algorithm?

AIMS/HYPOTHESIS

The leading cause of death in type 2 diabetes is cardiovascular disease (CVD). We examined the prevalence of myocardial ischaemia in type 2 diabetes patients and tried to establish an algorithm to identify patients with a high risk of ischaemic heart disease.

METHODS

Type 2 diabetes patients who had no known or suspected CVD, and had been referred consecutively to a diabetes clinic for the first time (n=305; age 58.6+/-11.3 years; diabetes duration 4.5+/-5.3 years) were screened for myocardial ischaemia using myocardial perfusion scintigraphy (MPS).

RESULTS

The univariate predictors of myocardial ischaemia were: atypical or typical angina pectoris, two or more traditional risk factors for CVD, BMI >32 kg/m2, systolic blood pressure >140 mmHg, HbA1c >8.5%, high-sensitivity C-reactive protein >4.0 mg/l, N-terminal pro-brain natriuretic peptide >300 pg/ml, left atrial volume index >32 ml/m2, left ventricular ejection fraction <50%, and carotid and peripheral arterial disease. The algorithm identified low (n=96), intermediate (n=65) and high risk groups (n=115), in which the prevalence of myocardial ischaemia was 15%,23% and 43%, respectively. Overall the algorithm reduced the number of patients referred to MPS from 305 to 144.However, the sensitivity and specificity of the algorithm was just 68% and 62%, respectively.

CONCLUSIONS/INTERPRETATION

Our algorithm was able to stratify which patients had a low, intermediate or high risk of myocardial ischaemia based on MPS. However, the algorithm had low sensitivity and specificity, combined with high cost and time requirements.

TRIAL REGISTRATION

clinicaltrials.gov NCT00298844 FUNDING: The study was funded by the Danish Cardio vascular Research Academy (DaCRA), The Danish Diabetes Association and The Danish Heart Foundation.

Cardiac outcomes after screening for asymptomatic coronary artery disease in patients with type 2 diabetes: the DIAD study: a randomized controlled trial

CONTEXT

Coronary artery disease (CAD) is the major cause of mortality and morbidity in patients with type 2 diabetes. But the utility of screening patients with type 2 diabetes for asymptomatic CAD is controversial.

OBJECTIVE

To assess whether routine screening for CAD identifies patients with type 2 diabetes as being at high cardiac risk and whether it affects their cardiac outcomes.

DESIGN, SETTING, AND PATIENTS

The Detection of Ischemia in Asymptomatic Diabetics (DIAD) study is a randomized controlled trial in which 1123 participants with type 2 diabetes and no symptoms of CAD were randomly assigned to be screened with adenosine-stress radionuclide myocardial perfusion imaging (MPI) or not to be screened. Participants were recruited from diabetes clinics and practices and prospectively followed up from August 2000 to September 2007.

MAIN OUTCOME MEASURE

Cardiac death or nonfatal myocardial infarction (MI).

RESULTS

The cumulative cardiac event rate was 2.9% over a mean (SD) follow-up of 4.8 (0.9) years for an average of 0.6% per year. Seven nonfatal MIs and 8 cardiac deaths (2.7%) occurred among the screened group and 10 nonfatal MIs and 7 cardiac deaths (3.0%) among the not-screened group (hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.44-1.88; P = .73). Of those in the screened group, 409 participants with normal results and 50 with small MPI defects had lower event rates than the 33 with moderate or large MPI defects; 0.4% per year vs 2.4% per year (HR, 6.3; 95% CI, 1.9-20.1; P = .001). Nevertheless, the positive predictive value of having moderate or large MPI defects was only 12%. The overall rate of coronary revascularization was low in both groups: 31 (5.5%) in the screened group and 44 (7.8%) in the unscreened group (HR, 0.71; 95% CI, 0.45-1.1; P = .14). During the course of study there was a significant and equivalent increase in primary medical prevention in both groups.

CONCLUSION

In this contemporary study population of patients with diabetes, the cardiac event rates were low and were not significantly reduced by MPI screening for myocardial ischemia over 4.8 years.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00769275.

Erectile dysfunction as a predictor of cardiovascular events and death in diabetic patients with angiographically proven asymptomatic coronary artery disease: a potential protective role for statins and 5-phosphodiesterase inhibitors

OBJECTIVES

We sought to investigate whether erectile dysfunction (ED) is a predictor of future cardiovascular events and death in diabetic patients with silent coronary artery disease (CAD) and whether there are predictors of cardiovascular events and death among CAD diabetic patients with ED.

BACKGROUND

Case-control studies showed that ED is associated with CAD in diabetic patients, but no prospective study is available.

METHODS

Type 2 diabetic men (n = 291) with silent CAD angiographically documented were recruited. Erectile dysfunction was assessed by the International Index Erectile Function-5 questionnaire.

RESULTS

During a follow-up period of 47.2 +/- 21.8 months (range 4 to 82 months), 49 patients experienced major adverse cardiac events (MACE). The difference in ED prevalence between patients with and those without MACE was significant (61.2% vs. 36.4%; p = 0.001). Cox regression analysis showed that ED predicted MACE (hazard ratio [HR] 2.1; 95% confidence interval [CI] 1.6 to 2.6; p < 0.001). Among patients with CAD and ED, the Kaplan-Meier method showed that the statin (Mantel log-rank test: 3.921; p = 0.048) and 5-phosphodiesterase (5-PDE) inhibitor use (Mantel log-rank test: 4.608; p = 0.032) were associated with a lower rate of MACE. Cox regression analysis showed that statin use (HR 0.66; 95% CI 0.46 to 0.97; p = 0.036) reduced MACE. Treatment with 5-PDE inhibitors did not enter the model, but its p value was very near to the significant level (HR 0.68; 95% CI 0.46 to 1.01; p = 0.056).

CONCLUSIONS

Our data first show that ED is a powerful predictor of cardiovascular morbidity and mortality in diabetic patients with silent CAD and that the treatment with statins and 5-PDE inhibitors might reduce the occurrence of MACE among CAD diabetic patients with ED.

Osteoprotegerin: a novel independent marker for silent myocardial ischemia in asymptomatic diabetic patients

OBJECTIVE

We sought to evaluate osteoprotegerin, an inhibitor of osteoclastogenesis involved in atherosclerosis, and other novel risk factors as predictive markers of silent myocardial ischemia (SMI).

RESEARCH DESIGN AND METHODS

A total of 465 consecutive diabetic patients with more than one additional risk factor were evaluated for SMI using stress myocardial perfusion imaging (MPI). We studied the association of SMI (positive stress electrocardiogram and/or abnormal MPI) with osteoprotegerin, other novel risk factors (lipoprotein[a], homocysteine, adiponectin, C-reactive protein, and fibrinogen), and conventional risk factors (total, LDL, and HDL cholesterol and triglycerides).

RESULTS

A total of 92 patients were diagnosed with SMI. Of the six novel markers, osteoprotegerin was the only one associated with SMI; the relative risk (RR) of SMI in patients with osteoprotegerin values above the 75th percentile was 3.19 (95% CI 1.99-5.18; P < 0.001) in comparison with those with osteoprotegerin below the 75th percentile. In univariate analyses, the other plasma markers significantly associated with SMI were higher triglycerides (P = 0.04) and lower HDL cholesterol (P = 0.02). The association of osteoprotegerin with SMI remained significant after correcting for other variables associated with SMI at P < 0.15 in univariate analysis (RR 3.95 [95% CI 2.21-7.06]; P < 0.0001). The association of osteoprotegerin with SMI was observed in male (P < 0.0001) and female (P = 0.03) patients, in type 1 (P = 0.002) and type 2 (P = 0.0004) diabetic patients, in patients with (P = 0.0004) or without (P = 0.03) nephropathy, and in patients without (P < 0.0001) but not with (P = 0.2) peripheral arterial disease.

CONCLUSIONS

Osteoprotegerin measurement, together with other conventional factors, can help to better define the diabetic population with an increased likelihood for SMI.

Prognostic significance of asymptomatic coronary artery disease in patients with diabetes and need for early revascularization therapy

AIMS

Information on the clinical outcome of patients with diabetes with silent myocardial ischaemia is limited. We compared the clinical and angiographic characteristics, and the clinical outcomes of diabetic patients with asymptomatic or symptomatic coronary artery disease (CAD).

METHODS

Three hundred and ten consecutive diabetic patients with CAD were divided into two groups according to the presence of angina and followed for a mean of 5 years. Fifty-six asymptomatic patients with a positive stress test and CAD on coronary angiography were compared with 254 symptomatic patients, 167 with unstable angina and 87 with chronic stable angina.

RESULTS

Although the severity of coronary atherosclerosis was similar in asymptomatic and symptomatic patients, revascularization therapy was performed less frequently in the asymptomatic than the symptomatic patients (26.8 vs. 62.0%; P < 0.001). Asymptomatic patients experienced a similar number of major adverse cardiac events (MACEs; death, non-fatal myocardial infarction, and revascularization; 32 vs. 28%; P = 0.57), but had higher cardiac mortality than symptomatic patients (26 vs. 9%; P < 0.001). However, patients who underwent revascularization therapy at the time of CAD diagnosis in these two groups showed similar MACE and cardiac mortality (20.0 vs. 22.5%, 6.7 vs. 5.3%, respectively; all P > 0.05).

CONCLUSIONS

This study suggests that diabetic patients with asymptomatic CAD have a higher cardiac mortality risk than those with symptomatic CAD, and that lack of revascularization therapy may be responsible for the poorer survival.

Effect of free fatty acid inhibition on silent and symptomatic myocardial ischemia in diabetic patients with coronary artery disease

OBJECTIVE

Free fatty acid inhibition with trimetazidine (TMZ) improves myocardial metabolism and myocardial ischemia in patients with coronary artery disease (CAD). Because of its effect on myocardial glucose utilization TMZ may represent a therapeutic option in diabetic patients with CAD. Aim of the present study was to evaluate whether the metabolic effect of TMZ may improve episodes of myocardial ischemia in diabetic patients with CAD.

RESEARCH DESIGN AND METHODS

We assessed the effect of TMZ on 24 h ambulatory ECG monitoring (AEM) in 30 patients (22 males and 8 females, mean (SE) age 67+/-6.5 years) with NIDDM and ischemic cardiomyopathy. Patients were randomized to receive on top of standard therapy either TMZ (20 mg, tds) or placebo (tds) and were evaluated at baseline and after 6 months.

RESULTS

Patients randomized to TMZ or placebo were comparable regarding demographic data, distribution of CAD, and glicated haemoglobin levels. TMZ significantly reduced the number of episodes of transient myocardial ischemia (-24% compared to baseline, p<0.01; -27% compared to placebo, p<0.01), and Total Ischemic Burden (-28% compared to baseline, p<0.01; -29% compared to placebo, p<0.01). TMZ also significantly reduced the number of silent episodes of myocardial ischemia (-42% compared to baseline and -39% compared to placebo, p<0.01) and the time of silent myocardial ischemia/24 h (-37% compared to baseline and -35% compared to placebo, p<0.01). No significant changes in heart rate were detected between baseline, placebo and TMZ evaluations.

CONCLUSIONS

TMZ is effective in reducing silent and symptomatic episodes of transient myocardial ischemia in diabetic patients with CAD on standard anti-anginal therapy.

The potential of myocardial perfusion scintigraphy for risk stratification of asymptomatic patients with type 2 diabetes

Patients with diabetes, in particular patients with type 2 diabetes, are at a 2- to 4-fold higher risk of cardiovascular mortality compared with their nondiabetic peers. Patients with diabetes are also more likely to have silent ischemia and less likely to survive a myocardial infarction than nondiabetic patients. Recent studies with electron beam computed tomography (EBCT) have shown that subclinical atherosclerosis is common in patients with diabetes, and studies with myocardial perfusion scintigraphy (with single-photon emission computed tomography) or stress echocardiography have demonstrated that between 25% and 50% of asymptomatic diabetic patients have ischemia during exercise or pharmacological stress and that a substantial proportion of these patients go on to develop major cardiovascular events within several years. Clearly, asymptomatic diabetic patients include a subset of individuals at high risk of cardiovascular disease who would benefit from improved risk stratification beyond that possible with risk factor scoring systems alone. Single-photon emission computed tomography, stress echocardiography, and possibly EBCT or multi-slice computed tomography, are emerging as valuable diagnostic tools for identifying asymptomatic diabetic patients who might require early and aggressive intervention to manage their cardiovascular risk.

Association of the metabolic syndrome and insulin resistance with silent myocardial ischemia in patients with type 2 diabetes mellitus

Metabolic syndrome is associated with elevated morbidity and mortality for overt coronary artery disease (CAD). In diabetic patients, CAD is often silent. The relation between metabolic syndrome and silent CAD has never been studied. We investigated whether metabolic syndrome is associated with silent CAD in patients with type 2 diabetes mellitus. We evaluated the prevalence of metabolic syndrome in 169 patients with uncomplicated diabetes and angiographically verified silent CAD and in 158 diabetic patients without myocardial ischemia on exercise electrocardiography, 48-hours ambulatory electrocardiography, and stress echocardiography. The groups were comparable for gender, age, glycemic control, and diabetes duration. Metabolic syndrome was defined according to the National Cholesterol Education Program criteria. To estimate insulin resistance in patients treated with diet alone or oral agents (122 patients with CAD and 115 patients without CAD), the Homeostasis Model Insulin-Resistance Assessment (HOMA) was used. The prevalence of metabolic syndrome (59.8% vs 44.3%, p = 0.005) and HOMA (5.4 +/- 2.1 vs 4.9 +/- 2.8, p = 0.044) were significantly higher in those with CAD than in those without CAD. Multiple logistic regression analysis showed that the metabolic syndrome was associated with silent CAD (odds ratio 2.44, 95% confidence interval 1.19 to 5.02, p = 0.015). Among patients on diet alone or oral agents, the HOMA was the strongest predictor of silent CAD (odds ratio 10.16, 95% confidence interval 2.60 to 39.63, p < 0.001). In conclusion, our data have shown an independent association of metabolic syndrome and insulin resistance with silent CAD in patients with type 2 diabetes mellitus. Other studies are needed to establish whether metabolic syndrome and HOMA are reliable markers to identify diabetic patients for additional screening for silent CAD.

Predictive value of silent myocardial ischemia for cardiac events in diabetic patients: influence of age in a French multicenter study

OBJECTIVE

Silent myocardial ischemia (SMI) in asymptomatic subjects with no history of myocardial infarction or angina is a frequent condition in diabetic patients. The aim of the study was to examine the predictive value of SMI for cardiac events in a multicenter cohort and to determine whether this value is higher in patients with a particular clinical profile.

RESEARCH DESIGN AND METHODS

A total of 370 asymptomatic diabetic patients with at least two additional cardiovascular risk factors was recruited in four departments of diabetology. SMI was assessed by either exercise or dipyridamole single-photon emission-computed tomography myocardial perfusion imaging with thallium-201. If dipyridamole stress was used, an electrocardiogram stress test was performed separately on another day. Follow-up duration was 3-89 months (38 +/- 23 months).

RESULTS

There was evidence of SMI in 131 patients (35.4%) on at least one positive noninvasive test. The patients with SMI were significantly older and had significantly higher serum triglycerides and lower HDL cholesterol levels. Cardiac events occurred in 53 patients (14.3%). Major cardiac events (death or myocardial infarction) occurred in 38 patients (10%) and other events (unstable angina, heart failure, or coronary revascularization) occurred in 15 patients. The patients who had cardiac events were older and had higher serum triglyceride levels at baseline. There was a significant association between SMI and cardiac events (hazard ratio 2.79 [95% CI 1.54-5.04]) and in particular major cardiac events (3 [1.53-5.87]). In the patients >60 years of age, the prevalence of SMI was higher (43.4 vs. 30.2% in those <60 years). SMI was associated with a significant risk of cardiac events (2.89 [1.31-6.39]) and in particular major cardiac events (3.66 [1.36-9.87]) for the patients >60 years old but not for those <60 years old.

CONCLUSIONS

In asymptomatic diabetic patients with additional cardiovascular risk factors, SMI is a potent predictor of cardiac events and should be assessed preferably in the patients >60 years of age.

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.

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.

No effect of statin therapy on silent myocardial ischemia in patients with type 2 diabetes without manifest cardiovascular disease

OBJECTIVE

Coronary artery disease is the most important cause of mortality in patients with type 2 diabetes. We aimed to determine the prevalence of silent myocardial ischemia (SMI) and the effect of statin therapy on SMI in type 2 diabetic patients without manifest cardiovascular disease.

RESEARCH DESIGN AND METHODS

A randomized, placebo-controlled, double-blind trial was performed in 250 patients with type 2 diabetes without manifest cardiovascular disease. Patients were given either 0.4 mg cerivastatin or placebo daily. In August 2001, when cerivastatin was withdrawn from the market, cerivastatin 0.4 mg was replaced by 20 mg simvastatin without deblinding the study. The primary end point was the change in ischemic episodes, duration, and burden as measured by 48-h ambulatory electrocardiography (AECG) over 2 years.

RESULTS

At baseline, 47 of 233 (20%) evaluable ambulatory electrocardiograms showed evidence of ischemia. After 2 years, there was a trend toward more ischemia in both treatment groups, without significant differences between the changes in ischemic parameters (episodes P = 0.498; duration P = 0.697; burden P = 0.798) in the two treatment groups. Cardiovascular events occurred in 12 patients in the placebo group and in two patients in the statin group (P = 0.006). There was no relationship between these cardiovascular events and the presence of SMI at baseline.

CONCLUSIONS

SMI occurred in 20% of type 2 diabetes patients without manifest cardiovascular disease. There was no effect from 2 years of statin therapy on SMI. In contrast, we observed a significantly lower cardiovascular event rate on statin therapy. AECG may not be a proper tool for risk stratification in patients with type 2 diabetes.

Lipoprotein(a), apolipoprotein(a) polymorphism and coronary atherosclerosis severity in type 2 diabetic patients

BACKGROUND

Few and conflicting data are available in the literature on the association between Lp(a) levels and the severity of coronary artery disease (CAD) in diabetic patients. In addition, no studies took into account the role of apo(a) polymorphism. The purpose of the present study was to analyse the association of the degree of coronary atherosclerosis with Lp(a) levels and apo(a) polymorphism in a large group of type 2 diabetic patients.

METHODS

The study population consisted of 227 consecutive type 2 diabetic patients undergoing a routine coronary angiography to evaluate chest pain or suspected CAD. The patients were subdivided into four subgroups according to the number of coronary arteries diseased: normal arteries (n=26), mono-vessel disease (n=67), bi-vessel disease (n=54) and multi-vessel disease (n=80).

RESULTS

Lp(a) levels (normal arteries: 14.6+/-19.6 mg/dl; mono-vessel disease: 19.0+/-16.4 mg/dl; bi-vessel disease: 19.3+/-15.1 mg/dl; multi-vessel disease: 26.5+/-16.8 mg/dl; p<0.001) and the percentages of patients with at least one isoform of low molecular weight (normal arteries: 23.1%; mono-vessel disease: 38.8%; bi-vessel disease: 75.9%; multi-vessel disease: 81.2%; p<0.001) were significantly correlated with increasing number of coronary vessels diseased. Multiple logistic regression analysis showed that both Lp(a) levels (OR: 1.31; 95% CI: 1.02-4.11) and apo(a) polymorphism (OR: 3.43; 95% CI: 1.67-7.05) were independent predictors of CAD severity.

CONCLUSIONS

Our data suggest that Lp(a) levels and apo(a) polymorphism may be reliable predictors of CAD severity in type 2 diabetic patients.

Plasma levels of soluble receptor for advanced glycation end products and coronary artery disease in nondiabetic men

OBJECTIVE

The receptor for advanced glycation end products (RAGE) is a cell surface receptor whose signaling pathway has been implicated in atherogenesis. RAGE has an endogenous secretory receptor form, called soluble RAGE (sRAGE), that could exert antiatherogenic effects by acting as a decoy. We sought to determine whether a decreased plasma level of sRAGE could be independently associated with the prevalence of coronary artery disease (CAD) in nondiabetic men.

METHODS AND RESULTS

Plasma levels of sRAGE were determined in 328 nondiabetic male patients with angiographically proved CAD and in 328 age-matched healthy controls. The concentration of sRAGE in plasma was significantly lower (P<0.0001) in CAD cases [median (interquartile range): 966 (658-1372) pg/mL] than in control subjects [1335 (936-1954) pg/mL]. In logistic regression analysis, the multivariate-adjusted odds ratio for the presence of CAD was 6.719 (95% confidence interval, 3.773 to 11.964; P<0.0001) when the lowest quartile of the sRAGE level was compared with the highest quartile.

CONCLUSIONS

Our findings indicate that low levels of sRAGE in plasma are independently associated with the presence of CAD in nondiabetic men and suggest that sRAGE is one of the clinically important molecules associated with atherosclerosis.

Relation of apolipoprotein(a) size to alzheimer's disease and vascular dementia

Lipoprotein(a) [Lp(a)] level is a newly established vascular risk factor which has been suggested to play a role in dementia. However, the majority of Lp(a) cell-to-cell interactions are mediated by its specific apolipoprotein(a) [apo(a)] moiety. This suggests that the size polymorphism of apo(a) may be of importance in conveying the Lp(a)-related risk. Specifically, we postulated that variation in apo(a) isoform size may lead to increased risk of vascular dementia (VaD), Alzheimer's disease (AD), stroke, or all three of them. Under a case-control design we compared Lp(a) plasma levels and the distribution of apo(a) phenotypes in groups of subjects consisting of 50 VaD patients, 162 sporadic AD patients, 95 non-demented stroke patients (NDS), and 105 normal controls. The prevalence of small-sized apo(a) isoforms in the VaD group was significantly higher than that in the stroke and normal control groups, with an odds ratio of 5.29 (95% CI 2.24-12.49, p = 0.0001) for the development of VaD for individuals with at least one apo(a) isoform of low molecular weight (LMW). Furthermore, the possession of at least one small-sized apo(a) isoform significantly increased the risk of AD to 1.92 (95% CI 1.02-3.61, p = 0.0434). Our results demonstrate that possession of at least one LMW apo(a) isoform is significantly associated with dementia and specifically offer new evidence of a strong association between the lipoprotein system and post-stroke dementia.

Detection of silent myocardial ischemia in asymptomatic diabetic subjects: the DIAD study

OBJECTIVE

To assess the prevalence and clinical predictors of silent myocardial ischemia in asymptomatic patients with type 2 diabetes and to test the effectiveness of current American Diabetes Association screening guidelines.

RESEARCH DESIGN AND METHODS

In the Detection of Ischemia in Asymptomatic Diabetics (DIAD) study, 1,123 patients with type 2 diabetes, aged 50-75 years, with no known or suspected coronary artery disease, were randomly assigned to either stress testing and 5-year clinical follow-up or to follow-up only. The prevalence of ischemia in 522 patients randomized to stress testing was assessed by adenosine technetium-99m sestamibi single-photon emission-computed tomography myocardial perfusion imaging.

RESULTS

A total of 113 patients (22%) had silent ischemia, including 83 with regional myocardial perfusion abnormalities and 30 with normal perfusion but other abnormalities (i.e., adenosine-induced ST-segment depression, ventricular dilation, or rest ventricular dysfunction). Moderate or large perfusion defects were present in 33 patients. The strongest predictors for abnormal tests were abnormal Valsalva (odds ratio [OR] 5.6), male sex (2.5), and diabetes duration (5.2). Other traditional cardiac risk factors or inflammatory and prothrombotic markers were not predictive. Ischemic adenosine-induced ST-segment depression with normal perfusion (n = 21) was associated with women (OR 3.4). Selecting only patients who met American Diabetes Association guidelines would have failed to identify 41% of patients with silent ischemia.

CONCLUSIONS

Silent myocardial ischemia occurs in greater than one in five asymptomatic patients with type 2 diabetes. Traditional and emerging cardiac risk factors were not associated with abnormal stress tests, although cardiac autonomic dysfunction was a strong predictor of ischemia.

Apoprotein(a) phenotypes and plasma lipoprotein(a) concentration in patients with diabetes mellitus

OBJECTIVES

To determine whether apo(a) isoforms and plasma Lp(a) concentrations in association with some lipid parameters increase the relative risk for the development of atherosclerosis in patients with diabetes mellitus (IDDM and NIDDM).

DESIGN AND METHODS

Apo (a) isoforms, Lp(a) and plasma lipids were determined in 40 IDDM and 65 NIDDM patients and in 182 healthy individuals. Apo(a) isoforms were separated by 3 to 15% gradient SDS-PAGE followed by immunoblotting.

RESULTS

Logistical analysis showed that: Lp(a) levels >30 mg/dL (RR = 0.25, p < 0.000001; RR = 0.18, p < 0.00002), HTA (RR = 0.212, p < 0.00001; RR = 0.30, p < 0.00001), LMW-S1 apo(a) isoform (RR = 6.86, p < 0.0131; RR = 7.04, p < 0.0057) play a significant role in aterogenecity in both groups of patients with DM (IDDM and NIDDM). The 6.50-fold increase in risk was found in NIDDM patients with high Lp(a) levels (>30 mg/dL) and plasma total/HDL cholesterol ratio (4.5-5.8).

CONCLUSION

Elevated Lp(a) levels, LMW S1 apo(a) isoform, HTA and combination of increased Lp(a) levels and total/HDL cholesterol ratio increase the risk for the development of atherosclerosis in patients with DM (IDDM and NIDDM).

Relationship between erectile dysfunction and silent myocardial ischemia in apparently uncomplicated type 2 diabetic patients

BACKGROUND

Erectile dysfunction (ED) is associated with coronary artery disease (CAD). In diabetic patients, CAD is often silent. Among diabetic patients with silent CAD, the prevalence of ED has never been evaluated. We investigated whether ED is associated with asymptomatic CAD in type 2 diabetic patients.

METHODS AND RESULTS

We evaluated the prevalence of ED in 133 uncomplicated diabetic men with angiographically verified silent CAD and in 127 diabetic men without myocardial ischemia at exercise ECG, 48-hour ambulatory ECG, and stress echocardiography. The groups were comparable for age and diabetes duration. Patients were screened for ED using the validated International Index of Erectile Function (IIEF-5) questionnaire. The prevalence of ED was significantly higher in patients with than in those without silent CAD (33.8% versus 4.7%; P=0.000). Multiple logistic regression analysis showed that ED, apolipoprotein(a) polymorphism, smoking, microalbuminuria, HDL, and LDL were significantly associated with silent CAD; among these risk factors, ED appeared to be the most efficient predictor of silent CAD (OR, 14.8; 95% CI, 3.8 to 56.9).

CONCLUSIONS

Our study first shows a strong and independent association between ED and silent CAD in apparently uncomplicated type 2 diabetic patients. If our findings are confirmed, ED may become a potential marker to identify diabetic patients to screen for silent CAD. Moreover, the high prevalence of ED among diabetics with silent CAD suggests the need to perform an exercise ECG before starting a treatment for ED, especially in patients with additional cardiovascular risk factors.

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.

Diagnosis of CAD in patients with diabetes: who to evaluate

Effective diagnosis and treatment of coronary artery disease (CAD) are key to the management of patients with diabetes. Although the use of specialized cardiac testing for CAD screening in asymptomatic patients varies widely and is the source of current controversy, evidence is emerging on the prevalence and predictors of asymptomatic ischemia in diabetic patients. Accurate diagnosis and risk stratification are essential in symptomatic patients with known or suspected CAD. Noninvasive cardiac testing has an important role in these patients, although evaluation for revascularization with cardiac catheterization is warranted in high-risk circumstances. This article reviews recent information that may help guide the clinician in the appropriate use of cardiac testing in diabetic patients.

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.