Prognostic value of dobutamine stress echocardiography in patients with diabetes

[Electrocardiography coupled with transthoracic echocardiography at rest in the diagnosis of cardiac impairments in type 2 diabetics: lessons learned from a cross-sectional case series in Burkina Faso]

Diabetes is a powerful independent cardiovascular risk factor. The aim of this study is to describe the electrocardiographic and echocardiographic abnormalities observed in patients with type 2 diabetes treated in the Department of Medicine at the University Hospital in Bobo-Dioulasso. We conducted a descriptive cross-sectional study of all patients with type 2 diabetes who gave consent from April to September 2014. We gathered clinical data from all the patients. They, moreover, underwent electrocardiography and doppler echocardiography. A total of 155 diabetics were investigated. The average age of patients was 55 years (IQR: 47-64) with a female predominance (sex ratio 0.5). Electrocardiographic abnormalities included repolarization abnormalities (31%) and atrial rhythm disorders (16,12%). Echocardiographic examination showed left ventricular hypertrophy (LVH) in 20,64% of cases. Left atrium was dilated in 14.19% of cases, LV was dilated in 1.3% of cases. Abnormal left ventricular ejection fraction was detected in 3.87% of cases. Nosological entities included hypertensive heart disease in 27 cases (54%), ischemic heart disease in 19 cases (38%), dilated cardiomyopathy in 2 cases (4%) and diabetic cardiomyopathy in 2 cases (4%). Heart failure was detected in 22 cases (44%) independently from cardiac impairment. Electrocardiographic and echocardiographic abnormalities are frequent in type 2 diabetes population at the University Hospital in Bobo-Dioulasso. Improved cooperation between cardiologists and diabetologists as well as the establishment of adequate technical screening equipment would be prerequisite for better cardiac risk stratification in this population.

Prognostic Value and Therapeutic Perspectives of Coronary CT Angiography: A Literature Review

Coronary stenosis severity is both a powerful and a still debated predictor of prognosis in coronary artery disease. Coronary computed tomographic angiography (CCTA) has emerged as a noninvasive technique that enables anatomic visualization of coronary artery disease (CAD). CCTA with newer applications, plaque characterization and physiologic/functional evaluation, allows a comprehensive diagnostic and prognostic assessment of otherwise low-intermediate subjects for primary prevention. CCTA measures the overall plaque burden, differentiates plaque subtypes, and identifies high-risk plaque with good reproducibility. Research in this field may also advance towards an era of personalized risk prediction and individualized medical therapy. It has been demonstrated that statins may delay plaque progression and change some plaque features. The potential effects on plaque modifications induced by other medical therapies have also been investigated. Although it is not currently possible to recommend routinely serial scans to monitor the therapeutic efficacy of medical interventions, the plaque modulation, as a part of risk modification, appears a feasible strategy. In this review we summarize the current evidence regarding vulnerable plaque and effects of lipid lowering therapy on morphological features of CAD. We also discuss the potential ability of CCTA to characterize coronary atherosclerosis, stratify prognosis of asymptomatic subjects, and guide medical therapy.

Coronary Atherosclerosis Assessment by Coronary CT Angiography in Asymptomatic Diabetic Population: A Critical Systematic Review of the Literature and Future Perspectives

The prognostic impact of diabetes mellitus (DM) on cardiovascular outcomes is well known. As a consequence of previous studies showing the high incidence of coronary artery disease (CAD) in diabetic patients and the relatively poor outcome compared to nondiabetic populations, DM is considered as CAD equivalent which means that diabetic patients are labeled as asymptomatic individuals at high cardiovascular risk. Lessons learned from the analysis of prognostic studies over the past decade have challenged this dogma and now support the idea that diabetic population is not uniformly distributed in the highest risk box. Detecting CAD in asymptomatic high risk individuals is controversial and, what is more, in patients with diabetes is challenging, and that is why the reliability of traditional cardiac stress tests for detecting myocardial ischemia is limited. Cardiac computed tomography angiography (CCTA) represents an emerging noninvasive technique able to explore the atherosclerotic involvement of the coronary arteries and, thus, to distinguish different risk categories tailoring this evaluation on each patient. The aim of the review is to provide a wide overview on the clinical meaning of CCTA in this field and to integrate the anatomical information with a reliable therapeutic approach.

Cardiac Imaging in the Diagnosis of Coronary Artery Disease

Coronary artery disease (CAD) continues to be a leading cause of morbidity and mortality worldwide. Although invasive coronary angiography has previously been the gold standard in establishing the diagnosis of CAD, there is a growing shift to more appropriately use the cardiac catheterization laboratory to perform interventional procedures once a diagnosis of CAD has been established by noninvasive imaging modalities rather than using it primarily as a diagnostic facility to confirm or refute CAD. With ongoing technological advancements, noninvasive imaging plays a pre-eminent role in not only diagnosing CAD but also informing the choice of appropriate therapies, establishing prognosis, all while containing costs and providing value-based care. Multiple imaging modalities are available to evaluate patients suspected of having coronary ischemia, such as stress electrocardiography, stress echocardiography, single-photon emission computed tomography myocardial perfusion imaging, positron emission tomography, coronary computed tomography (CT) angiography, and magnetic resonance imaging. These imaging modalities can variably provide functional and anatomical delineation of coronary stenoses and help guide appropriate therapy. This review will discuss their advantages and limitations and their usage in the diagnostic pathway for patients with CAD. We also discuss newer technologies such as CT fractional flow reserve, CT angiography with perfusion, whole-heart coronary magnetic resonance angiography with perfusion, which can provide both anatomical as well as functional information in the same test, thus obviating the need for multiple diagnostic tests to obtain a comprehensive assessment of both, plaque burden and downstream ischemia. Recognizing that clinicians have a multitude of tests to choose from, we provide an underpinning of the principles of ischemia detection by these various modalities, focusing on anatomy vs physiology, the database justifying their use, their prognostic capabilities and lastly, their appropriate and judicious use in this era of patient-centered, cost-effective imaging.

Long-Term (>10 Years) Prognostic Value of Dobutamine Stress Echocardiography in a High-Risk Cohort

The prognostic value of dobutamine stress echocardiography (DSE) at >10-year follow-up is unknown. The aim of this study was to assess the very long-term prognostic value of DSE in a high-risk cohort of patients with known or suspected coronary artery disease. This prospective, single-center study included 3,381 patients who underwent DSE from January 1990 to January 2003. Two-dimensional echocardiographic images were acquired at rest, during dobutamine stress, and during recovery. Follow-up events were collected and included overall mortality, cardiac death, nonfatal myocardial infarction, and revascularization. The incremental value of DSE in the prediction of selected end points was evaluated using multivariate Cox proportional hazard analysis. During a mean follow-up of 13 ± 3.2 years (range 7.3 to 20.5 years), there were 1,725 deaths (51%), of which 1,128 (33%) were attributed to cardiac causes. Patients with an abnormal DSE had a higher mortality rate (44% vs 35% at 15-year follow-up, p <0.001) than those with a normal DSE. When comparing echocardiographic variables at rest to variables at maximum dose dobutamine, the chi-square of the test improved from 842 to 870 (p <0.0001) and from 684 to 740 (p <0.0001) for all-cause mortality and cardiac death, respectively. DSE provided incremental value in predicting all-cause mortality, cardiac death, and hard cardiac events. There seems, however, to be a "warranty period" of approximately 7 years, when the survival curves of a normal and abnormal DSE no longer diverge.

Effect of tighter glycemic control on cardiac function, exercise capacity, and muscle strength in heart failure patients with type 2 diabetes: a randomized study

OBJECTIVES

In patients with type 2 diabetes (T2D) and heart failure (HF), the optimal glycemic target is uncertain, and evidence-based data are lacking. Therefore, we performed a randomized study on the effect of optimized glycemic control on left ventricular function, exercise capacity, muscle strength, and body composition.

DESIGN AND METHODS

40 patients with T2D and HF (left ventricular ejection fraction (LVEF) 35±12% and hemoglobin A1c (HbA1c) 8.4±0.7% (68±0.8 mmol/mol)) were randomized to either 4-month optimization (OPT group) or non-optimization (non-OPT group) of glycemic control. Patients underwent dobutamine stress echocardiography, cardiopulmonary exercise test, 6 min hall-walk test (6-MWT), muscle strength examination, and dual X-ray absorptiometry scanning at baseline and at follow-up.

RESULTS

39 patients completed the study. HbA1c decreased in the OPT versus the non-OPT group (8.4±0.8% (68±9 mmol/mol) to 7.6±0.7% (60±7 mmol/mol) vs 8.3±0.7% (67±10 mmol/mol) to 8.4±1.0% (68±11 mmol/mol); p<0.001). There was no difference between the groups with respect to changes in myocardial contractile reserve (LVEF (p=0.18)), oxygen consumption (p=0.55), exercise capacity (p=0.12), and 6-MWT (p=0.84). Muscle strength decreased in the non-OPT compared with the OPT group (37.2±8.1 to 34.8±8.3 kg vs 34.9±10.2 to 35.4±10.7 kg; p=0.01), in line with a non-significant decrease in lean (p=0.07) and fat (p=0.07) tissue mass in the non-OPT group. Hypoglycemia and fluid retention did not differ between groups.

CONCLUSIONS

4 months of optimization of glycemic control was associated with preserved muscle strength and lean body mass in patients with T2D and HF compared with lenient control, and had no deleterious effect on left ventricular contractile function and seemed to be safe.

TRIAL REGISTRATION NUMBER

NCT01213784; pre-results.

The prognostic value of dobutamine stress echocardiography amongst British Indian Asian and Afro-Caribbean patients: a comparison with European white patients

Background

The incidence of cardiovascular disease is considerably disparate among different racial and ethnic populations. While dobutamine stress echocardiography (DSE) has been shown to be useful in Caucasian patients, its role among ethnic minority groups remains unclear. This study aimed to investigate the prognostic importance of DSE in three ethnic groups in the UK.

Methods

DSE was performed on 6231 consecutive patients. After exclusions, 5329 patients formed the study (2676 [50.2 %] Indian Asian, 2219 [41.6 %] European white and 434 [8.1 %] Afro-Caribbean). Study outcome measures were non-fatal cardiac events (NFCE) and all-cause mortality.

Results

There were 849 (15.9 %) NFCE and 1365 (25.6 %) deaths over a median follow-up period of 4.6 years. In total 1174 (22 %) patients had inducible myocardial ischaemia during DSE, 859 (16.1 %) had fixed wall motion abnormalities and 3645 (68.4 %) patients had a normal study. Ethnicity did not predict events. Among the three ethnic groups, ischaemia on DSE was associated with 2 to 2.5 times the risk of non-fatal cardiac events and 1.2 to 1.4 times the risk of all-cause mortality. Peak wall motion score index was the strongest independent predictor of non-fatal cardiac events and all-cause mortality in all groups. The C statistic for the prediction of NFCE and all-cause mortality were significantly higher when DSE parameters were added to the standard risk factors for all ethnic groups.

Conclusions

DSE is a strong predictor of NFCE and all-cause mortality and provides predictive information beyond that provided by standard risk factors in three major racial and ethnic groups. No major differences among racial and ethnic groups in the predictive value of DSE was detected.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-015-0028-1) contains supplementary material, which is available to authorized users.

Prognostic value of calcium score and coronary flow velocity reserve in asymptomatic diabetic patients

BACKGROUND

The risk stratification of patients with diabetes mellitus (DM) is a major objective for the clinicians, and it can be achieved by coronary flow velocity reserve (CFVR) or with coronary artery calcium score (CS). CS evaluates underlying coronary atherosclerotic plaque burden and CFVR estimates both presence of coronary artery stenosis and microvascular function. Consequently, CFVR may provide unique risk information beyond the extent of coronary atherosclerosis.

AIM

Our aim is to assess joint prognostic value of CFVR and CS in asymptomatic DM patients.

MATERIALS AND METHODS

We prospectively included 200 asymptomatic patients (45,5 % male, mean age 57,35 ± 11,25), out of which, there were 101 asymptomatic patients with DM and 99 asymptomatic patients without DM, but with one or more conventionally risk factors for coronary artery disease. We analyzed clinical, biochemical, metabolic, inflammatory parameters, CS by Agatston method, transthoracic Doppler echocardiography CFVR of left anterior descending artery and echocardiographic parameters.

RESULTS

Total CS and CS LAD were significantly higher, while mean CFVR was lower in diabetics compared to the nondiabetics. During 1 year follow-up, 24 patients experienced cardio-vascular events (one cardiovascular death, two strokes, three myocardial infarctions, nine new onsets of unstable angina and nine myocardial revascularizations): 19 patients with DM and five non DM patients, (p = 0,003). Overall event free survival was significantly higher in non DM group, compared to the DM group (94,9 % vs. 81,2 %, p = 0,002 respectively), while the patients with CS ≥200 and CFVR <2 had the worst outcome during 1 year follow up in the whole study population as well as in the DM group. At multivariable analysis CFVR on LAD (HR 12.918, 95 % CI 3.865-43.177, p < 0.001) and total CS (HR 13.393, 95 % CI 1.675-107.119, p = 0.014) were independent prognostic predictors of adverse events in DM group of patients.

CONCLUSION

Both CS and CFVR provide independent and complementary prognostic information in asymptomatic DM patients. When two parameters are analyzed together, the risk stratification ability improves, even when DM patients are analyzed together with non DM patients. As a result, DM patients with CS ≥200 and CFVR <2 had the worst outcome. Consequently, the use of two tests identified subset of patients who can derive the most benefit from the intensive prevention measures.

Adding liraglutide to the backbone therapy of biguanide in patients with coronary artery disease and newly diagnosed type-2 diabetes (the AddHope2 study): a randomised controlled study protocol

INTRODUCTION

Newly diagnosed type 2 diabetes mellitus (T2DM) in patients with coronary artery disease (CAD) more than doubles the risk of death compared with otherwise matched glucose tolerant patients. The biguanide metformin is the drug of choice in treatment of T2DM and has shown to ameliorate cardiovascular morbidity in patients with T2DM and myocardial infarction (MI). The incretin hormone, glucagon-like peptide-1 (GLP-1) improves β-cell function, insulin sensitivity and causes weight loss and has been suggested to have beneficial effects on cardiac function. The GLP-1 receptor agonist (GLP-1RA), liraglutide, is currently used for treatment of T2DM but its potential effect on cardiac function has not been investigated in detail. We hypothesised that liraglutide added to metformin backbone therapy in patients with CAD and newly diagnosed T2DM will improve β-cell function and left ventricular systolic function during dobutamine stress.

METHODS AND ANALYSES

40 patients with CAD and newly diagnosed T2DM will receive the intervention liraglutide+metformin and placebo+metformin in this investigator-initiated, double blind, randomised, placebo-controlled, cross-over 12 plus 12 weeks intervention study with a 2-week washout period. The primary cardiovascular end point is changes in left ventricular ejection fraction during stress echocardiography. The primary endocrine end point is β-cell function evaluated during a frequently sampled intravenous glucose tolerance test. Secondary end points include heart rate variability, diurnal blood pressure, glucagon suppression and inflammatory response (urine, blood and adipose tissue).

ETHICS AND DISSEMINATION

This study is approved by the Danish Medicines Agency, the Danish Dataprotection Agency and the Regional Committee on Biomedical Research Ethics of the Capital Region of Denmark. The trial will be carried out under the guidance from the GCP unit at Copenhagen University Hospital of Bispebjerg and in accordance with the ICH-GCP guidelines and the Helsinki Declaration.

TRIAL REGISTRATIONS NUMBER

Clinicaltrials.gov ID: NCT01595789, EudraCT: 2011-005405-78.

Coronary artery disease screening in type II diabetic patients: prognostic value of rest and stress echocardiography

AIM

Presence of inducible ischemia in type II diabetic patients is associated with an adverse outcome, but less is known about prognostic value of resting wall motion abnormalities (WMA).

MATERIALS AND METHODS

From October 2006 to May 2008, 278 patients underwent to CAD screening, according to ADA criteria, by dobutamine stress echocardiography (DSE). Between July and September 2009, all patients were contacted to verify the occurrence of new cardiac events.

RESULTS

Resting-WMA were present in 63 patients; 88 subjects showed inducible ischemia. During the follow-up, we observed 24 new cardiac events; patients with a good outcome showed less frequently resting WMA (19 vs 50%). Inducible ischemia (71% vs 28%; p<0.001) and a more extensive area of inducible ischemia, expressed by a higher value of peak WMSI (1.63±0.45 vs 1.17±0.31; p<0.0001), were more frequent in patients with adverse outcome. A Cox regression analysis showed that only a higher peak WMSI (HR 6.645, 95% CI 2.782-15.874, p<0.0001) was associated with a bad outcome. Event-free survival was lower in presence of rest WMA (79% vs 94%, p<0.0001) and a higher peak WMSI (66% vs 95%, p<0.0001).

CONCLUSIONS

In diabetic patients presence of an extensive inducible ischemia was independently associated with a worst outcome; resting WMA were associated with reduced event-free survival.

Hybrid SPECT/CT Imaging in the Evaluation of Coronary Stenosis: Role in Diabetic Patients

Purpose. Our purpose was to combine the results of the MDCT (multidetector computed tomography) morphological data and the SPECT (single-photon emission computed tomography) data using hybrid imaging to overcome the limits of the MDCT in the evaluation of coronary stenosis in diabetic patients with large amount of calcium in the coronary arteries. Method and Materials. 120 diabetic patients underwent MDCT examination and SPECT examination. We evaluated 324 coronary arteries. After the examinations, we merged CT and SPECT images. Results. CT evaluation: 52 (32.8%) coronaries with stenosis ≥ 50%, 228 (70.4%) with stenosis < 50%, and 44 (13.6%) with a doubtful evaluation. SPECT evaluation: 80 (24.7%) areas with hypoperfusion, 232 (71.6%) with normal perfusion, and 12 (3.7%) with a doubtful evaluation. Of 324 coronary arteries and corresponding areas, the hybrid SPECT/CT evaluation showed 92 (28.4%) areas with hypoperfusion, and 232 (71.6%) with normal perfusion. Conclusion. Hybrid CT/SPECT imaging could be useful in the detection of significant coronary stenosis in patients with large amount of coronary calcifications.

Myocardial ischaemia without obstructive coronary artery disease in rheumatoid arthritis: hypothesis-generating insights from a cross-sectional study

OBJECTIVE

RA is associated with increased cardiovascular events, reportedly to equal diabetes mellitus (DM). The presence of myocardial ischaemia was assessed in asymptomatic high-risk RA patients and compared with patients with DM and a healthy control group.

METHODS

Eighteen consecutive non-diabetic RA patients without known cardiovascular disease who developed a new carotid atheromatic plaque during the last 3 years were matched 1:1 for traditional cardiovascular risk factors with asymptomatic type 2 DM patients and 1:2 with asymptomatic non-RA, non-DM control subjects. After dobutamine stress contrast echocardiography with wall-motion and perfusion evaluation, coronary angiography was performed in those with positive stress tests.

RESULTS

Ischaemia by echocardiography was found in 67% of RA patients; this was significantly higher than controls (31%, P = 0.019) but comparable to those with DM (78%, P = 0.71). Angiography performed in eight consenting RA patients was normal in four, revealed non-flow-limiting coronary atheromatic lesions in two and significant lesions in two patients. RA patients with ischaemia had CRP serum levels significantly higher by six-fold compared with those with normal stress echocardiography.

CONCLUSION

Asymptomatic RA patients may display myocardial ischaemia at similar levels to DM patients but with low prevalence of obstructive coronary artery disease. Microvascular abnormalities associated with increased inflammatory response may account for these findings. Their exact nature and significance require further evaluation.

Long-term prognostic value of dobutamine stress echocardiography in diabetic patients with limited exercise capability: a 13-year follow-up study

OBJECTIVE

To determine the incremental prognostic value of dobutamine stress echocardiography (DSE) at 13-year follow-up (SD 3.2 years) for predicting mortality and cardiac events in diabetic patients.

RESEARCH DESIGN AND METHODS

A total of 396 diabetic patients (mean age 61 ± 11 years; 252 men [64%]) with limited exercise capacity who underwent DSE for evaluation of ischemia were studied. End points were all causes of mortality, cardiac death, and hard cardiac events (cardiac death and nonfatal myocardial infarction).

RESULTS

During a mean follow-up of 13 years, 230 patients (58%) died (121 cardiac deaths), and 30 patients had nonfatal myocardial infarction. Cumulative survival in patients with an abnormal DSE at 5, 10, and 15 years was 68, 49, and 41%, respectively. In patients with a normal DSE, these respective numbers were 74, 57, and 44%. Multivariate analyses showed that DSE provided incremental value over clinical characteristics and stress test parameters for prediction of mortality and cardiac events. Survival analysis showed that DSE provided optimal risk stratification up to 7 years after initial testing; after that period, the risk of adverse outcome increased comparably in both normal and abnormal DSE patients.

CONCLUSIONS

DSE provided restricted predictive value of adverse outcome in patients with diabetes who were unable to perform an adequate exercise stress test. DSE provided optimal risk stratification up to 7 years after initial testing. Repeated DSE at that time might add to its prognostic value.

Does the prognostic value of dobutamine stress echocardiography differ among different age groups?

BACKGROUND

Age is associated with reduced exercise capacity and greater prevalence of coronary artery disease. Whether the prognostic information obtained from dobutamine stress echocardiography (DSE), a stress test commonly used for patients unable to perform an exercise test, provides differential information based on age is not well known.

METHODS

We studied 6,655 consecutive patients referred for DSE. Patients were divided into 3 age groups: (1) <60 years (n = 1,389), (2) 60 to 74 years (n = 2,978), and (3) ≥75 years (n = 2,288). Mean follow-up was 5.5 ± 2.8 years. End points included all-cause mortality and cardiac events, including myocardial infarction and late (>3 months) coronary revascularization.

RESULTS

Peak stress wall motion score index was an independent predictor of cardiac events in all age groups (<60 years: hazard ratio [HR] 1.14, P = .02; 60-74 years: HR 1.70, P < .0001; ≥75 years: HR 1.10, P = .006). In patients ≥75 years, peak wall motion score index (HR 1.10, P < .0001) and abnormal left ventricular end-systolic volume response (HR 1.25, P = .03) were independent predictors of death. In patients aged 60 to 74 years, abnormal left ventricular end-systolic volume response (HR 1.43, P = .0003) was independently related to death, whereas in patients <60 years, the echocardiographic data assessed during stress were not a predictor.

CONCLUSIONS

Dobutamine stress echocardiography provided independent information predictive of cardiac events among all age groups and death in patients ≥60 years. However, among patients <60 years, stress-induced echocardiographic abnormalities were not independently associated with mortality. Comorbidities, which have precluded exercise testing, may be most relevant in predicting mortality in patients <60 years undergoing DSE.

[Screening of silent myocardial ischaemia by dobutamine stress echocardiography among type 2 diabetics at high cardiovascular risk in Senegal]

INTRODUCTION

Diabetes is a major risk factor for coronary artery disease witch may develop insidiously. Several non-invasive methods are used to detect silent myocardial ischaemia, especially in diabetic patients at high cardiovascular risk. We project to screen, by dobutamine stress echocardiography, silent myocardial ischaemia in type 2 diabetics in Senegal.

METHODOLOGY

We randomly recruited in hospital in Senegal type 2 diabetics aged at least 40 years and a dobutamine stress echocardiography was performed in those selected according to the French Society of Cardiology and the French Language Association for the Study of Diabetes and Metabolic Diseases.

RESULTS

Dobutamine stress echocardiography was performed in 79 diabetics at high cardiovascular risk, including 56 women. The average age was 58.8±11.8 years. The exam was positive in 67.1% of cases (53/79), with a predominance of motion abnormalities in anterior territory (83%). Cardiovascular risk factors associated with positivity of test were microalbuminuria (p=0.0001), inactivity (p=0.0001), dyslipidemia (p=0.0002), arterial hypertension (p=0.001), smoking (0.003) and male sex (p=0.004).

CONCLUSION

In Africa, dobutamine stress echocardiography has the advantage of its accessibility and its feasibility. Early detection of silent myocardial ischaemia in diabetics at high risk could optimize their care.

Diabetes: prognostic value of CT coronary angiography--comparison with a nondiabetic population

PURPOSE

To evaluate the prognostic value of multidetector computed tomographic (CT) coronary angiography in a diabetic population known to have or suspected of having coronary artery disease (CAD) compared with that in nondiabetic individuals.

MATERIALS AND METHODS

Institutional review board approval and patient informed consent were obtained. Three hundred thirteen patients with type 2 diabetes mellitus (DM) and 303 patients without DM underwent unenhanced 64-detector row CT, at which a calcium score was obtained, followed by CT angiography. Multidetector CT coronary angiograms were retrospectively classified as normal, showing nonobstructive CAD (<or=50% luminal narrowing), or showing obstructive CAD (>50% luminal narrowing). During follow-up after CT angiography, major events (cardiac death, nonfatal myocardial infarction, and unstable angina requiring hospitalization) and total events (major events plus coronary revascularizations) were recorded for each patient. Cox proportional hazards analysis and Kaplan-Meier analysis were used to compare survival rates.

RESULTS

In the group of 313 patients with DM, there were 213 men, and the mean age was 62 years +/- 11 (standard deviation). In the group of 303 patients without DM, there were 203 men, and the mean age was 63 years +/- 11. The mean number of diseased segments (5.6 vs 4.4, P = .001) and the rate of obstructive CAD (51% vs 37%, P < .001) were higher in patients with DM. Patients were followed up for a mean of 20 months +/- 5.4 (range, 6-44 months). At multivariate analysis, DM (P < .001) and evidence of obstructive CAD (P < .001) were independent predictors of outcome. Obstructive CAD remained a significant multivariate predictor for both patients with DM and patients without DM. In both patients with DM and patients without DM with absence of disease, the event rate was 0%. The event rate increased to 36% in patients without DM but with obstructive CAD and was highest (47%) in patients with DM and obstructive CAD.

CONCLUSION

In both patients with DM and patients without DM, multidetector CT coronary angiography provides incremental prognostic information over baseline clinical variables, and the absence of atherosclerosis at CT coronary angiography is associated with an excellent prognosis. Multidetector CT coronary angiography might be a clinically useful tool for improving risk stratification in both patients with DM and patients without DM.

Diagnostic and prognostic testing to evaluate coronary artery disease in patients with diabetes mellitus

Coronary artery disease (CAD) continues to be the most common cause of morbidity and mortality in patients with diabetes mellitus (DM). In recent years, the strategies for treatment of CAD in DM have undergone much evolution. Currently, all patients with DM, regardless of symptoms or diagnosed CAD, are treated aggressively for CAD risk factor reduction. In this clinical climate, the ability to specifically identify patients with disease that will benefit from more aggressive and invasive therapies remains a challenge. In this article we review the current literature on diagnostic and prognostic utility of conventional non-invasive modalities for assessment of CAD in patients with DM, as well as on novel and emerging methods for CAD risk stratification.

Prognostic value of dobutamine stress echocardiography in diabetic patients

CAD is the main cause of morbidity and mortality in diabetic patients; we need reliable clinical parameters to stratify cardiovascular risk in these patients. We thus assessed prognostic value of clinical parameters, rest and stress echocardiographic data in diabetic patients, with known or suspected CAD. We studied 322 type 2 diabetic patients, who underwent dobutamine stress echocardiography (DSE) for known or suspected CAD; for prognostic assessment, end-points were all-cause mortality and hard cardiac events (cardiac death and non fatal myocardial infarction). During DSE, viability and inducible ischemia developed in 65 (20%) and 192 (60%) subjects, respectively; a severe ischemia (an asynergic area including more than 40% of all segments combined with a rate pressure product < 17,000) appeared in 88 (27%). Presence of a diabetic treatment or microvascular diabetic complications didn't influence prognosis, while a longer diabetes duration was associated with a higher all-cause mortality at univariate analysis. At multivariate analysis, an advanced age (RR = 1.108, CI: 1.039-1.182, P = 0.002), a lower left ventricular ejection fraction (RR = 0.956, CI: 0.919-0.994, P = 0.025) and, tendentially, peripheral vascular disease (RR = 2.942, CI: 0.985-8.785, P = 0.053) independently determined an increased all-cause mortality. New hard cardiac events occurred more frequently in presence of peripheral vascular disease (RR = 2.975, CI: 1.339-6.608, P = 0.007), viability (RR = 3.427, CI: 1.400-8.390, P = 0.007) and severe ischemia (RR = 3.245, CI: 1.503-7.005, P = 0.003). In diabetic patients with known or suspected CAD, presence of viability and severe ischemia during DSE are independently associated with higher occurrence of hard cardiac events.

Silent myocardial ischemia screening in patients with diabetes mellitus

The prevalence of diabetes mellitus is fairly increasing, especially in the developing countries. Diabetes is a major cardiovascular risk factor; it often leads to severe cardiovascular complications, and coronary artery disease (CAD) is the main cause of death in diabetic patients. Silent myocardial ischemia (SMI) is more frequent in diabetic patients. The progress made in detection and treatment of CAD allows reconsidering the screening of SMI, in the hope that early CAD diagnosis leads to a more effective therapy and the decrease of cardiovascular complications and mortality. However, the benefit of systematic SMI screening remains discussed. Current guidelines recommend screening SMI in asymptomatic diabetic patients selected for high cardiovascular risk (i.e. with two or more other cardiovascular risk factors, or peripheral or carotid arterial disease, or proteinuria). ECG stress test can be recommended in first intention if maximal heart rate can be achieved. For patient with inconclusive ECG stress test, myocardial scintigraphy seems more accurate than stress echocardiography. Coronary angiogram should be performed in case of positive stress test. Further evaluations of systematic screening have to be conducted on broad randomized trial.

The additional prognostic power of diabetes mellitus on coronary flow reserve in patients with suspected coronary artery disease

AIMS

The aim of the present study was to assess the relative prognostic value of coronary flow reserve (CFR) and diabetes mellitus (DM) in patients with suspected coronary artery disease (CAD).

METHODS

We prospectively studied 347 inhospital patients with chest pain. Coronary angiography was performed in 281 patients (81%). All patients underwent a transthoracic echocardiographic study to evaluate left ventricular function and a stress vasodilator transoesophageal echocardiographic study to evaluate simultaneously CFR and the degree of aortic atherosclerosis (AA). The primary outcome of the study was cardiovascular mortality.

RESULTS

During a mean follow-up of 41+/-12 months, 22 patients suffered cardiovascular death. Diabetic patients had a significantly higher AA grade and tended to have a lower CFR and more often significant CAD. Patients with normal CFR had less often significant CAD and tended to have less often DM. Significant univariable predictors of cardiovascular survival were DM, LV end-diastolic diameter, CFR and AA grade. Multivariable regression analysis showed that only CFR (hazard ratio (HR) 2.9, P=0.01) and diabetes (HR 3.1, P=0.01) were independent predictors of cardiovascular survival.

CONCLUSIONS

CFR and DM evaluations offer complementary information during vasodilator stress TEE testing. Patients with reduced CFR (impaired microcirculatory function) and DM have the worst prognosis.

Additional prognostic value of coronary flow reserve in diabetic and nondiabetic patients with negative dipyridamole stress echocardiography by wall motion criteria

OBJECTIVES

The aim of this prospective, multicenter, observational study was to compare the prognostic value of Doppler echocardiographic-derived coronary flow reserve (CFR) in diabetic and nondiabetic patients with known or suspected coronary artery disease and negative dipyridamole stress echocardiography.

BACKGROUND

The prognostic value of CFR in diabetic patients with negative stress echocardiography remains unknown.

METHODS

The study group consisted of 1,130 patients (207 diabetics) with known (n = 418) or suspected (n = 712) coronary artery disease and negative stress echocardiography by wall motion criteria. All underwent dipyridamole (up to 0.84 mg/kg over 6 min) echocardiography with CFR evaluation of left anterior descending artery by Doppler. A value of CFR < or =2.0 was considered abnormal.

RESULTS

Coronary flow reserve was abnormal in 309 (27%) patients. During a median follow-up of 16 months, 98 events (8 deaths, 24 ST-segment elevation myocardial infarctions, and 66 non-ST-segment elevation myocardial infarctions) occurred. In addition, 101 patients underwent revascularization and were censored. Multivariable prognostic indicators were abnormal CFR (p < 0.0001), anti-ischemic therapy at the time of testing (p = 0.002), age (p = 0.02), and resting wall motion abnormality (p = 0.05). The event rate was markedly higher (p < 0.0001) for both diabetic and nondiabetic patients with abnormal CFR as compared with diabetic and nondiabetic patients with normal CFR. Of note, a preserved CFR off therapy identified diabetic and nondiabetic patients with better survival and comparable yearly event rates (2.2% vs. 2.0%, p = 0.80).

CONCLUSIONS

Coronary flow reserve provides independent prognostic information in diabetic and nondiabetic patients with known or suspected coronary artery disease and negative dipyridamole stress echocardiography. In particular, a normal CFR off therapy is associated with better and similar survival in the 2 populations.

Prognostic significance of myocardial ischemia during dobutamine stress echocardiography in asymptomatic patients with diabetes mellitus and no prior history of coronary events

The prognostic significance of myocardial ischemia assessed by dobutamine stress echocardiography in asymptomatic patients with diabetes mellitus who have no previous coronary artery disease remains unclear. We assessed the value of dobutamine stress echocardiography for risk stratification in 161 asymptomatic patients with type 2 diabetes (mean 62 +/- 12 years of age; 96 men) who had no previous myocardial infarction or revascularization. End point during follow-up was hard cardiac events (cardiac death and nonfatal myocardial infarction). Ischemia was detected in 45 patients (28%). During a median follow-up of 5 years, 40 patients (25%) died (18 cardiac deaths) and 7 patients had nonfatal myocardial infarction (25 hard cardiac events). An abnormal dobutamine stress echocardiogram was associated with a higher mortality compared with a normal dobutamine stress echocardiogram (p = 0.03). In an incremental multivariate analysis model, clinical predictors of hard cardiac events were age and hypercholesterolemia. Ischemia was incremental to the clinical parameters. In conclusion, myocardial ischemia is an independent predictor of cardiac events in asymptomatic diabetic patients with no previous coronary artery disease.

Noninvasive assessment of plaque characteristics with multislice computed tomography coronary angiography in symptomatic diabetic patients

OBJECTIVE

Cardiovascular events are high in patients with type 2 diabetes, whereas their risk stratification is more difficult. The higher risk may be related to differences in coronary plaque burden and composition. The purpose of this study was to evaluate whether differences in the extent and composition of coronary plaques in patients with and without diabetes can be observed using multislice computed tomography (MSCT).

RESEARCH DESIGN AND METHODS

MSCT was performed in 215 patients (86 [40%] with type 2 diabetes). The number of diseased coronary segments was determined per patient; each diseased segment was classified as showing obstructive (> or = 50% luminal narrowing) disease or not. In addition, plaque type (noncalcified, mixed, and calcified) was determined. Plaque characteristics were compared in patients with and without diabetes. Regression analysis was performed to assess the correlation between plaque characteristics and diabetes.

RESULTS

Patients with diabetes showed significantly more diseased coronary segments than nondiabetic patients (4.9 +/- 3.5 vs. 3.9 +/- 3.2, P = 0.03) with more nonobstructive (3.7 +/- 3.0 vs. 2.7 +/- 2.4, P = 0.008) plaques. Relatively more noncalcified (28 vs. 19%) and calcified (49 vs. 43%) and less mixed (23 vs. 38%) plaques were observed in patients with diabetes (P < 0.0001). Diabetes correlated with the number of diseased segments and nonobstructive, noncalcified, and calcified plaques.

CONCLUSIONS

Differences in coronary plaque characteristics on MSCT were observed between patients with and without diabetes. Diabetes was associated with higher coronary plaque burden. More noncalcified and calcified plaques and less mixed plaques were observed in diabetic patients. Thus, MSCT may be used to identify differences in coronary plaque burden, which may be useful for risk stratification.

Assessing prognosis in patients with diabetes mellitus--the Achilles' heel of cardiac stress imaging tests?

The prognostic utility of stress imaging studies has been validated in numerous studies and, in general, patients with a normal imaging study have annual cardiac ischemic event rates of <1%. However, this predictive value of a normal stress imaging study does not appear to be applicable to subjects with diabetes. In this editorial, we summarize the current available data on prognostic utility of stress imaging studies in subjects with diabetes and provide insights into how to interpret and integrate these data for daily clinical practice. In conclusion, currently available data suggest that the prognostic value of stress imaging studies in subjects with diabetes differs from those without diabetes and should be interpreted as such.

Prognostic value of dobutamine stress echocardiography in patients with chronic kidney disease

BACKGROUND

Although dobutamine stress echocardiography (DSE) is cited in clinical guidelines for the evaluation of patients with chronic kidney disease (CKD), there are limited data regarding its prognostic utility in this setting. The current study assesses the prognostic value of DSE in patients with CKD.

METHODS

Four hundred eighty-five patients with CKD (on renal dialysis or with creatinine > 3 mg/mL) who had DSE were followed for 2.3 +/- 1.8 years.

RESULTS

One hundred eighty-eight (39%) patients died during follow-up. Patients with extensive ischemia (affecting > 25% of myocardial segments) had a 1- and 3-year survival rate of 77% and 48%, respectively, compared with 83% and 52% in those with lesser degrees (< or = 25% segments affected) of ischemia and with 88% and 70% in those with a normal DSE. In multivariate analyses, the percentage of ischemic segments on DSE was an independent predictor of all-cause mortality (hazard ratio, 1.40 per 25% increase; 95% CI, 1.16-1.68; P = .001). Inclusion of DSE data improved the predictive value of the best clinical model (chi2, 83.6-97.4; P = .003).

CONCLUSION

In patients with CKD, the percentage of ischemic segments during DSE is an independent predictor of mortality and provides prognostic information that is incremental to clinical data.

Six-year follow-up of a cohort of 203 patients with diabetes after screening for silent myocardial ischaemia

AIMS

To determine the prognosis of patients with Type 1 or Type 2 diabetes, 6 years after screening for silent myocardial ischaemia (SMI).

METHODS

Two hundred and three asymptomatic patients with diabetes underwent systematic SMI screening. From the results of this screening, they were allocated to one of three groups: patients (n = 171) with negative screening; patients (n = 32) with positive screening; and patients (n = 21) with positive screening and coronary stenosis. Six years after the initial assessment, all patients were re-assessed. All events [death, cardiac death, non-fatal major cardiac events (NFMCEs)--acute myocardial infarction, ventricular rhythm disorders, heart failure, unstable angina] were recorded.

RESULTS

Fifteen patients were lost to follow-up. Patients (n = 20) with positive SMI screening and coronary stenosis had a higher risk of NFMCEs (35% vs. 7%, P < 0.001), and a higher mortality rate (35% vs. 15%, P < 0.05) compared with patients (n = 157) with negative screening. SMI-positive patients (n = 31) had a higher NFMCE rate compared with negative SMI screening patients, although overall mortality rate was no different. Cancer was the leading cause of death (36.4%). In multivariate analysis, major cardiac events (cardiac death and NFMCE) were related to baseline age, body mass index and coronary stenosis (P < 0.01).

CONCLUSIONS

Patients with diabetes and SMI have a very poor prognosis as assessed by cardiac events or death, especially in the presence of coronary stenosis.

Diagnostic and prognostic value of non-invasive imaging in known or suspected coronary artery disease

The role of non-invasive imaging techniques in the evaluation of patients with suspected or known coronary artery disease (CAD) has increased exponentially over the past decade. The traditionally available imaging modalities, including nuclear imaging, stress echocardiography and magnetic resonance imaging (MRI), have relied on detection of CAD by visualisation of its functional consequences (i.e. ischaemia). However, extensive research is being invested in the development of non-invasive anatomical imaging using computed tomography or MRI to allow detection of (significant) atherosclerosis, eventually at a preclinical stage. In addition to establishing the presence of or excluding CAD, identification of patients at high risk for cardiac events is of paramount importance to determine post-test management, and the majority of non-invasive imaging tests can also be used for this purpose. The aim of this review is to provide an overview of the available non-invasive imaging modalities and their merits for the diagnostic and prognostic work-up in patients with suspected or known CAD.

Dobutamine stress echocardiography in patients with diabetes mellitus: enhanced prognostic prediction using a simple risk score

OBJECTIVES

We sought to determine the prognostic value of dobutamine stress echocardiography (DSE) for predicting long-term outcomes in a large cohort with diabetes mellitus and to develop a simple risk score using clinical and echocardiographic data.

BACKGROUND

Neither risk scores nor long-term prognostic value of DSE has been described in a large diabetic population.

METHODS

We studied 2,349 patients with diabetes mellitus (1,338 men, 67 +/- 11 years of age) during a follow-up of 5.4 +/- 2.2 years.

RESULTS

Mortality and morbidity (myocardial infarction and late coronary revascularization) occurred in 1,044 (44%) and 309 (13%) patients, respectively. Addition of stress echocardiographic variables to the clinical and rest echocardiographic model provided incremental prognostic information for predicting mortality (chi-square = 243 to 270, p < 0.0001) and morbidity (chi-square = 38 to 78, p < 0.0001). For each end point, a simple risk score was derived according to the estimated values of beta coefficients of multivariate predictors (insulin therapy, smoking, failure to achieve target heart rate, percentage of ischemic segments, and impaired left ventricular systolic function) and resulted in an assessment of risk among all age groups. The C-statistic values were 0.60 to 0.64, indicating modest discrimination. The estimated five-year event-free survivals of patients in three risk categories were 94%, 86%, and 80% for morbidity (p < 0.00001) and 69%, 60%, and 47% for mortality (p < 0.0001).

CONCLUSIONS

In patients with diabetes mellitus, a simple and practical risk score using clinical variables and results of DSE stratified patients into three risk groups for mortality and cardiovascular morbidity.

Prognostic value of pharmacological stress echocardiography in diabetic and nondiabetic patients with known or suspected coronary artery disease

OBJECTIVES

We sought to compare the prognostic value of pharmacological stress echocardiography (SE) in diabetic and nondiabetic patients with known or suspected coronary artery disease.

BACKGROUND

Although SE is a useful tool for risk stratification of patients with diabetes, it has not been established whether it retains the same prognostic information in diabetic patients compared with nondiabetic patients.

METHODS

A total of 5,456 patients (749 diabetics) undergoing dipyridamole (n = 3,306) or dobutamine (n = 2,150) SE were prospectively followed up for the occurrence of hard events (death and/or nonfatal myocardial infarction).

RESULTS

During a median time of 31 months, 411 deaths and 236 infarctions occurred. There were 132 events in diabetic patients and 515 in nondiabetic patients (18% vs. 11%, respectively; p < 0.0001). Moreover, 1,607 (29%) patients underwent coronary revascularization and were censored. Ischemia at SE, resting wall motion score index, and age were independent predictors of death and hard events in both diabetic and nondiabetic patients. Compared with a normal test, ischemia and scar test patterns were associated to significantly lower age-corrected five-year hard event-free survival in diabetic as well as nondiabetic patients. However, a normal test was associated with a greater than two-fold annual event rate in diabetic patients as compared with nondiabetics who were either younger (2.6% vs. 1.0%) or older (5.5% vs. 2.2%) than 65 years of age.

CONCLUSIONS

Stress echocardiography is equally effective in risk stratifying diabetic and nondiabetic patients independently of age. However, the normal test result predicts a less favorable outcome in diabetic than in nondiabetic patients.

Quantitative Assessment of Left Ventricular Function During Contrast-Enhanced Dobutamine Stress Echocardiography Predicts Future Cardiac Events in Diabetic Patients

BACKGROUND

Non-invasive diagnosis and risk stratification of coronary artery disease are important for the selection and optimization of therapeutic interventions in diabetic patients, which may improve survival. The aim of this study was to determine the incremental value of contrast-enhanced dobutamine stress echocardiography (CE-DSE) for risk stratification.

METHODS AND RESULTS

CE-DSE was performed in 326 patients with diabetes mellitus (mean age; 66 +/- 10 years, 223 men). All patients were followed up for a mean of 29 months (1-61 months). Dobutamine was infused in a standard protocol with an intravenous contrast agent. The primary endpoints for hard cardiac events included cardiac death and nonfatal myocardial infarction. The primary endpoints for total cardiac events included hard cardiac events, unstable angina pectoris, congestive heart failure, and late coronary revascularization (> 3 months). Cardiac events occurred in 74 patients. The addition of the CE-DSE results, including abnormal left ventricular end-systolic volume response and left ventricular ejection fraction at peak stress < 50%, to the clinical and rest echocardiography model provided incremental information in predicting total cardiac events (increase in chi-square value for the model from 17 to 24, p < 0.05) and hard cardiac events (increase in chi-square value for the model from 18 to 24, p < 0.05).

CONCLUSIONS

Quantitative assessment of left ventricular function during CE-DSE provides incremental prognostic information in predicting cardiac events in diabetic patients.

Stress myocardial scintigraphy and dobutamine echocardiography in the detection of coronary disease in asymptomatic patients with type 2 diabetes

OBJECTIVE

The aims of this prospective study were: (1) to compare stress thallium-201 single photon emission computed tomography (SPECT) and dobutamine echocardiography (DE) in the detection of silent myocardial ischemia (SMI) in asymptomatic high risk diabetic patients; (2) to analyse long-term outcome after intensive care of SMI in these patients.

METHODS

SPECT was performed in 100 high risk diabetic patients and DE in the first 75 patients. Coronary angiography was realized in patients with SMI, with revascularization for suitable lesions. Intensive treatment of atherosclerosis risk factors was performed in all patients. Patients were followed 2 +/- 0.5 years for the subsequent occurrence of cardiac death, myocardial infarction and revascularization.

RESULTS

SMI was detected by SPECT in 62% and by DE in 10% of the patients (p < 0.0001), whereas significant coronary stenosis at angiography was detected by SPECT in 26% and by DE in 5% of the patients (p < 0.02). Independent predictive factors of significant coronary stenosis were male gender (p < 0.03) and peripheral arterial disease (p < 0.007). Nonfatal acute coronary syndrome occurred during follow-up in 2 patients (2%). Subsequent revascularization procedure was needed in 9 patients. Baseline patients' characteristics, as well as SMI, were not predictive of cardiac event during follow up.

CONCLUSION

SPECT seems more accurate than DE to detect significant coronary stenosis in high risk asymptomatic diabetic patients. In this population, aggressive treatment of SMI with systematic revascularization combined with intensive care of risk factors is associated with a favorable long-term prognosis, similar in diabetic patients with and without initial SMI.

The use of stress echocardiography for prognostication in coronary artery disease: an overview

PURPOSE OF REVIEW

Stress echocardiography has a high accuracy for the detection of coronary artery disease. Additionally, it provides clinically useful prognostic information, such as resting left ventricular function, myocardial viability, stress-induced ischemia, vascular extent of wall motion abnormalities, and changes in end-systolic volume and ejection fraction with stress.

RECENT DEVELOPMENTS

The timing, extent, and severity of the stress-induced wall motion abnormalities are important determinants of long-term prognosis. Previous studies have shown the efficacy of stress echocardiography in predicting long-term cardiac events in mixed patient groups and the value of this test in selected patient subsets.

SUMMARY

This review attempts to define the role of stress echocardiography for prognostication in coronary artery disease, pointing out the ability of this technique to identify low-risk and high-risk subsets among patients with known or suspected coronary artery disease and thus guide patient management decisions.

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.

Long-term prognostic value of ejection fraction changes during dobutamine???atropine stress echocardiography

OBJECTIVE

Dobutamine stress echocardiography (DSE), using subjective wall motion scoring, provides incremental prognostic information over clinical data. The aim of the study was to test the additional prognostic value of left ventricular ejection fraction (LVEF) changes during DSE at different stages.

METHODS

The study population comprised 106 consecutive patients (mean age 60+/-11 years, 73% men) with suspected or known coronary artery disease referred for DSE. Stress-induced ischemia was defined as new or worsening wall motion abnormalities. LVEF was measured at rest, peak stress and recovery. Follow-up was successful in 104 (98%) patients. Four patients who underwent revascularization within 60 days were excluded from the analysis. End-points during follow-up were cardiac death, non-fatal myocardial infarction and late revascularization.

RESULTS

During a mean follow-up of 5.3+/-2.1 years, 26% of patients died: 13% due to cardiac death, 6% patients experienced non-fatal myocardial infarction and 38% underwent late revascularization. Rest-to-peak LVEF increase was lower in patients who experienced cardiac death or non-fatal myocardial infarction (4.9+/-8.6 compared with 9.2+/-7.5, P=0.04) and any cardiac events (6.0+/-8.5 compared with 10.5+/-6.7, P=0.004). An inverse correlation was found between left ventricular ejection increase and the number of ischemic segments (P<0.0001). A multivariable Cox proportional hazard model demonstrated that, in addition to clinical data and new wall motion abnormalities, lower LVEF increase had an incremental prognostic value in predicting hard cardiac events (hazard ratio 1.1, 95% confidence interval 1.0-1.2).

CONCLUSION

Failure of LVEF to significantly increase during DSE, denoting more extensive ischemia, identifies a higher-risk subgroup for late cardiac events.

Prognostic value of exercise echocardiography in patients with diabetes mellitus and known or suspected coronary artery disease

To assess the prognostic value of exercise echocardiography in subjects who had diabetes, we studied 214 patients who had 28 hard cardiac events (cardiac death in 15, myocardial infarction in 13) during a follow-up of 44 +/- 16 months. Independent risk factors for predicting cardiac events were insulin therapy (odds ratio 2.313), peak left ventricular ejection fraction (odds ratio 0.973), and ischemia detected by exercise echocardiography (odds ratio 2.513).

Noninvasive diagnosis of coronary artery disease in patients with diabetes by dobutamine stress real-time myocardial contrast perfusion imaging

OBJECTIVE

The aim of this study was to assess the accuracy of real-time myocardial contrast perfusion imaging (MCPI) during dobutamine stress in the diagnosis and localization of coronary artery disease (CAD) in patients with diabetes. Myocardial contrast echocardiography is a new technique that allows evaluation of myocardial perfusion. Its utility in diabetic patients has not been defined.

RESEARCH DESIGN AND METHODS

Dobutamine-atropine stress test was performed in conjunction with MCPI using Optison or Definity at rest and at peak stress in 128 patients with diabetes and suspected CAD who underwent coronary angiography within 1 month. CAD was defined as > or =50% stenosis in one or more coronary artery. MCPI was considered diagnostic of CAD in the presence of reversible perfusion abnormalities. The normalcy rate of MCPI was additionally determined in 18 asymptomatic nondiabetic patients with low probability.

RESULTS

CAD was detected in 101 (79%) patients by angiography. Reversible perfusion abnormalities were detected in 90 patients with and 13 patients without CAD. The overall sensitivity of MCPI was 89% (95% CI 83-95), specificity 52% (33-71), and accuracy 81% (75-88). Reversible abnormalities were detected in two or more vascular distributions in 44 of 56 patients with multivessel CAD and in 8 of 63 patients without (sensitivity 68%, specificity 87%, positive predictive value 84%, and accuracy 79%). Regional sensitivity was 75% (65-85) for left anterior descending CAD, 71% (60-83) for left circumflex, and 67% (55-78) for right CAD. MCPI was normal in 16 of the 18 patients with low clinical probability of CAD (normalcy rate 89%).

CONCLUSIONS

MCPI is a useful noninvasive technique for the diagnosis and localization of CAD in diabetic patients. The extent of perfusion abnormalities can identify patients with multivessel CAD with a moderate sensitivity and high specificity.

Noninvasive angiography and assessment of left ventricular function using multislice computed tomography in patients with type 2 diabetes

OBJECTIVE

Early identification of coronary artery disease (CAD) in patients with diabetes is important because these patients are at increased risk for CAD and have worse outcome than nondiabetic patients after CAD is diagnosed. Recently, noninvasive coronary angiography and assessment of left ventricular function has been demonstrated with multislice computed tomography (MSCT). The purpose of the present study was to validate this approach in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

MSCT was performed in 30 patients with confirmed type 2 diabetes. From the MSCT images, coronary artery stenoses (> or =50% luminal narrowing) and left ventricular function (left ventricular ejection fraction, regional wall motion) were evaluated and compared with results of conventional angiography and two-dimensional echocardiography.

RESULTS

Two hundred twenty of 256 coronary artery segments (86%) were interpretable with MSCT. In these segments, sensitivity and specificity for detection of coronary artery stenoses were 95%. Including the uninterpretable segments, sensitivity and specificity were 81 and 82%, respectively. Bland-Altman analysis in the comparison of left ventricular ejection fractions demonstrated a mean difference of -0.48 +/- 3.8% for MSCT and echocardiography, which was not significantly different from 0. Agreement between the two modalities for assessment of regional contractile function was excellent (91%, kappa statistic 0.81).

CONCLUSIONS

Accurate noninvasive evaluation of both the coronary arteries and left ventricular function with MSCT is feasible in patients with type 2 diabetes. This noninvasive approach may allow optimal identification of high-risk patients.

Prognostic value of dobutamine stress echocardiography in patients with previous coronary revascularisation

OBJECTIVE

To assess the prognostic value of dobutamine stress echocardiography (DSE) in patients with previous myocardial revascularisation.

DESIGN

Prospective study.

SETTING

Tertiary referral centre in Rotterdam, the Netherlands.

PATIENTS

332 consecutive patients with previous percutaneous or surgical coronary revascularisation underwent DSE. Follow up was successful for 331 (99.7%) patients. Thirty eight patients who underwent early revascularisation (<or= 3 months) after the test were excluded from analysis.

MAIN OUTCOME MEASURES

Cox proportional hazards regression models were used to identify independent predictors of the composite of cardiac events (cardiac death, non-fatal myocardial infarction, and late revascularisation).

RESULTS

During a mean (SD) of 24 (20) months, 37 (13%) patients died and 89 (30%) had at least one cardiac event (21 (7%) cardiac deaths, 11 (4%) non-fatal myocardial infarctions, and 68 (23%) late revascularisations). In multivariate analysis of clinical data, independent predictors of late cardiac events were hypertension (hazard ratio (HR) 1.7, 95% confidence interval (CI) 1.1 to 2.6) and congestive heart failure (HR 2.1, 95% CI 1.3 to 3.2). Reversible wall motion abnormalities (ischaemia) on DSE were incrementally predictive of cardiac events (HR 2.1, 95% CI 1.3 to 3.2).

CONCLUSIONS

Myocardial ischaemia during DSE is independently predictive of cardiac events among patients with previous myocardial revascularisation, after controlling for clinical data.