Assessment of subclinical coronary atherosclerosis in asymptomatic patients with type 2 diabetes mellitus with single photon emission computed tomography and coronary computed tomography angiography

10. Cardiovascular Disease and Risk Management: Standards of Care in Diabetes-2024

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, an interprofessional expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

10. Cardiovascular Disease and Risk Management: Standards of Care in Diabetes-2023

The American Diabetes Association (ADA) "Standards of Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations and a full list of Professional Practice Committee members, please refer to Introduction and Methodology. Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Atherosclerotic plaque characteristics on quantitative coronary computed tomography angiography associated with ischemia on positron emission tomography in diabetic patients

Patients with diabetes mellitus (DM) may show diffuse coronary artery atherosclerosis on coronary computed tomography angiography (CTA). The present study aimed at quantification of atherosclerotic plaque with CTA and its association with myocardial ischemia on positron emission tomography (PET) in DM patients. Of 922 symptomatic outpatients without previously known coronary artery disease who underwent CTA, 115 with DM (mean age 65 ± 8 years, 58% male) who had coronary atherosclerosis and underwent both quantified CTA (QCTA) and PET were included in the study. QCTA analysis was performed on a per-vessel basis and the most stenotic lesion of each vessel was considered. Myocardial ischemia on PET was based on absolute myocardial blood flow at stress ≤ 2.4 ml/g/min. Of the 345 vessels included in the analysis, 135 (39%) had flow-limiting stenosis and were characterized by having longer lesions, higher plaque volume, more extensive plaque burden and higher percentage of dense calcium (37 ± 22% vs 28 ± 22%, p = 0.001). On univariable analysis, QCTA parameters indicating the degree of stenosis, the plaque extent and composition were associated with presence of ischemia. The addition of the QCTA degree of stenosis parameters (x2 36.45 vs 88.18, p < 0.001) and the QCTA plaque extent parameters (x2 88.18 vs 97.44, p = 0.01) to a baseline model increased the association with ischemia. In DM patients, QCTA variables of vessel stenosis, plaque extent and composition are associated with ischemia on PET and characterize the hemodynamic significant atherosclerotic lesion.

10. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2022

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc22-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc22-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

10. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2021

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc21-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc21-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

10. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2020

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes the ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee (https://doi.org/10.2337/dc20-SPPC), are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction (https://doi.org/10.2337/dc20-SINT). Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

10. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2019

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

The associated risk factors for coronary artery calcium in asymptomatic individuals with and without diabetes in rural Central Appalachia

AIM

To examine the risk factor of coronary artery calcium (CAC) in individuals with diabetes and those without diabetes in Central Appalachia.

METHODS

Study population included 2479 asymptomatic participants who underwent CAC screening between August 2012 and November 2016. CAC score was classified into four categories [0 (no plaque), 1-99 (mild plaque), 100-399 (moderate plaque), and ≥400 (severe plaque)]. Multinomial logistic regression analyses were conducted to test the association between CAC and cardiovascular disease (CVD) risk factors among participants with diabetes, age and gender matched controls, and randomly selected controls.

RESULTS

13.6% of total participants had diabetes. Around 69%, 59.8%, and 57.7% of the participants with diabetes, matched controls, and randomly selected controls had CAC score ≥1, respectively. Participants with diabetes had higher prevalence of all CVD risk factors than controls. Among participants with diabetes, hypertension and physical inactivity increased the odds of CAC = 100-399, while among those without diabetes, hypertension and hypercholesteremia increased the odds of having CAC = 1-99 and CAC ≥ 400.

CONCLUSION

Half of study participants had subclinical atherosclerosis (i.e., CAC), and individuals with diabetes had higher CAC scores. This study suggests that individuals with diabetes in Central Appalachia might benefit from screening for CAC.

9. Cardiovascular Disease and Risk Management: Standards of Medical Care in Diabetes-2018

The American Diabetes Association (ADA) "Standards of Medical Care in Diabetes" includes ADA's current clinical practice recommendations and is intended to provide the components of diabetes care, general treatment goals and guidelines, and tools to evaluate quality of care. Members of the ADA Professional Practice Committee, a multidisciplinary expert committee, are responsible for updating the Standards of Care annually, or more frequently as warranted. For a detailed description of ADA standards, statements, and reports, as well as the evidence-grading system for ADA's clinical practice recommendations, please refer to the Standards of Care Introduction Readers who wish to comment on the Standards of Care are invited to do so at professional.diabetes.org/SOC.

Noninvasive Cardiovascular Risk Assessment of the Asymptomatic Diabetic Patient: The Imaging Council of the American College of Cardiology

Increased cardiovascular morbidity and mortality in patients with type 2 diabetes is well established; diabetes is associated with at least a 2-fold increased risk of coronary heart disease. Approximately two-thirds of deaths among persons with diabetes are related to cardiovascular disease. Previously, diabetes was regarded as a "coronary risk equivalent," implying a high 10-year cardiovascular risk for every diabetes patient. Following the original study by Haffner et al., multiple studies from different cohorts provided varying conclusions on the validity of the concept of coronary risk equivalency in patients with diabetes. New guidelines have started to acknowledge the heterogeneity in risk and include different treatment recommendations for diabetic patients without other risk factors who are considered to be at lower risk. Furthermore, guidelines have suggested that further risk stratification in patients with diabetes is warranted before universal treatment. The Imaging Council of the American College of Cardiology systematically reviewed all modalities commonly used for risk stratification in persons with diabetes mellitus and summarized the data and recommendations. This document reviews the evidence regarding the use of noninvasive testing to stratify asymptomatic patients with diabetes with regard to coronary heart disease risk and develops an algorithm for screening based on available data.

Long Term Prognostic Value of a Negative Work-Up for Acute Coronary Disease in Emergency Department Chest Pain Patients Without Known Coronary Artery Disease: A Cohort Study

BACKGROUND

To determine the rate of all cause and cardiac death, new myocardial infarction (MI) or coronary revascularisation at over three years from index visit in emergency department chest pain patients without known coronary artery disease (CAD) at index presentation who had a negative electrocardiogram (ECG) and biomarker workup for acute coronary syndrome (ACS).

METHODS

An unplanned sub-study of a prospective observational study of consecutive adult patients presenting to the ED with atraumatic chest pain (or equivalents). The primary outcome of interest was the predictive performance of a negative ECG and biomarker work-up for ACS for all cause and cardiac mortality over more than three years' follow-up in patients not known to have pre-existing CAD presenting to the ED with chest pain. Secondary outcomes were rate of new MI or revascularisation not related to the index visit.

RESULTS

237 patients were studied. Median age was 52 years (IQR 42 - 62) and 55.3% were male. Median follow-up was 48 months. There were seven deaths (3%, 95% CI 1.4 - 6%), one of which was potentially cardiac in origin with cause of death given as pulmonary hypertension and cardiac failure (0.4%, 95% CI 0.02 - 2.3%). There was one confirmed MI (0.6%, 95% CI 0.03 - 3.8%). The rate of revascularisation not related to the index visit was 3.1% (95% CI 1.1 - 7.4%).

CONCLUSION

Patients who present to ED with potentially cardiac chest pain but who do not have known CAD, and have non-ischaemic ECGs and troponin assays below the 99^th percentile are at low risk of cardiac death or MI in long-term follow-up. This challenges the recommendation for routine functional or anatomic testing.

The Incremental Prognostic Value of Cardiac Computed Tomography in Comparison with Single-Photon Emission Computed Tomography in Patients with Suspected Coronary Artery Disease

Background

Coronary computed tomographic angiography (CCTA) facilitates comprehensive evaluation of coronary artery disease (CAD), including plaque characterization, and can provide additive diagnostic value to single-photon emission computed tomography (SPECT). However, data regarding the incremental prognostic value of CCTA to SPECT remain sparse. We evaluated the independent and incremental prognostic value of CCTA, as compared with clinical risk factors and SPECT.

Materials and methods

A total of 1,077 patients with suspected CAD who underwent both SPECT and cardiac CT between 2004 and 2012 were enrolled retrospectively. Presence of reversible or fixed perfusion defect (PD) and summed stress score were evaluated on SPECT. Presence, extent of coronary atherosclerosis and diameter stenosis (DS) were evaluated on CCTA. Plaque composition was categorized as non-calcified, mixed, or calcified according to the volume of calcified component (>130 Hounsfield Units). Patients were followed up for the occurrence of adverse cardiac events including cardiac death, non-fatal myocardial infarction, unstable angina, and late revascularization (>90 days after imaging studies).

Results

During follow-up (median 23 months), adverse cardiac events were observed in 71 patients (6.6%). When adjusted for clinical risk factors and SPECT findings, the presence of any coronary plaque, any plaque in ≥3 segments, coronary artery calcium score (CACS) ≥400, a plaque ≥50% DS, presence of non-calcified plaque (NCP) or mixed plaque (MP), and NCP/MP in ≥2 segments were independent predictors of adverse cardiac events; however, the presence of calcified plaque (CP) was not. Conventional CCTA findings, including CACS ≥400 and a plaque ≥50% DS, demonstrated incremental prognostic value over clinical risk factors and SPECT (χ² 54.19 to 101.03; p <0.001). Addition of NCP/MP in ≥2 segments resulted in further significantly improved prediction (χ² 101.03 to 113.29; p <0.001).

Conclusion

Comprehensive CCTA evaluation of coronary atherosclerosis provides independent and incremental prognostic value in relation to SPECT evaluation of myocardial ischemia. Specifically, segmentally-analyzed plaque composition with CCTA provides further risk stratification in addition to CACS and DS.

Relationship between glycemic control and coronary artery disease severity, prevalence and plaque characteristics by computed tomography coronary angiography in asymptomatic type 2 diabetic patients

Evaluate whether glycemic control in type 2 diabetes (DM2) asymptomatic for coronary artery disease (CAD) affects not only the presence and magnitude of CAD but also the characteristics of plaque vulnerability using multidetector row computed coronary tomography (MDCT). Acute coronary syndrome (ACS) is frequently observed in asymptomatic DM2 patients. Positive vessel remodeling (PR) and low-attenuation plaques (LAP) identified by MDCT have been demonstrated to be characteristics of subsequent culprit lesions of ACS. However, little is known regarding plaque characteristics in asymptomatic diabetic patients and their relationship with glycemic control. Ninety asymptomatic DM2 patients, aged 40-65 years old, underwent MDCT. The presence of atherosclerotic obstruction, defined as coronary stenosis ≥50 %, and plaque characteristics were compared between two groups of patients with A1c < 7 and A1c ≥ 7 %. Of the 90 patients, 38 (42.2 %) presented with coronary atherosclerotic plaques, 11 had A1c < 7 % and 27 had A1c ≥ 7 % (p = 0.0006). Fourteen patients had significant lumen obstruction higher than 50 %: 3 in the A1c < 7 % group and 11 in the A1c ≥ 7 % group (p = 0.02). Non-calcified plaque was more prevalent in the A1c ≥ 7 % group (p = 0.005). In eleven patients, the simultaneous presence of two vulnerability plaque characteristics (PR and LAP) were observed more frequently in the A1c ≥ 7 group (n = 8) than in the A1c < 7 group (n = 3) (p = 0.04). Asymptomatic DM2 patients with A1c ≥ 7 % have a higher frequency of CAD and a higher proportion of vulnerable atherosclerotic coronary plaque by MDCT compared to patients with DM2 with A1c < 7 in our study.

Coronary Artery Disease Screening With Carotid Ultrasound Examination by a Primary Care Physician

Background

In this study, we investigated the feasibility of primary care physicians using carotid ultrasound to perform coronary artery disease screening in asymptomatic patients with multiple coronary risk factors.

Methods

We retrospectively collected the data of 135 consecutive asymptomatic patients (mean age: 68.5 ± 8.4 years; male, 75%) who were referred to our institution due to abnormal findings on a carotid ultrasound performed by a primary care physician and who underwent coronary computed tomography angiography.

Results

The mean number of risk factors was 4.1 ± 1.2 and the mean intima-media thickness was 2.00 ± 0.63 mm. Mild (≤ 50%), moderate (51-75%), and severe (> 76%) coronary stenosis was observed in 54 (40%), 27 (20%), and 25 patients (19%), respectively, while no plaque was found in 24 patients (18%), and five patients (4%) could not be evaluated due to calcification. Consequently, coronary angiography was performed in 56 (41%) patients and coronary intervention was required in 31 patients (23%). A multivariate logistic regression analysis demonstrated that the ratio of low-density lipoprotein cholesterol levels to high-density lipoprotein cholesterol levels, the use of calcium channel blockers and the value of the diastolic blood pressure were related to > 50% coronary stenosis.

Conclusions

The use of carotid ultrasound in the coronary artery disease screening by primary care physicians resulted in a high prevalence of coronary artery disease and high probabilities of coronary angiography and revascularization, and thus it is considered to be a useful and feasible strategy for the screening of asymptomatic patients.

Use of imaging and clinical data to screen for cardiovascular disease in asymptomatic diabetics

Background

There is increasing evidence to suggest that not all individuals with type 2 diabetes mellitus (T2DM) have equal risk for developing cardiovascular disease. We sought to compare the yield of testing for pre-clinical atherosclerosis with various approaches.

Methods

98 asymptomatic individuals with T2DM without known coronary artery disease (CAD) were enrolled in a prospective study and underwent carotid ultrasound, exercise treadmill testing (ETT), coronary artery calcium (CAC) scoring, and coronary computed tomography angiography (CTA).

Results

Of 98 subjects (average age 55 ± 6, 64 % female), 43 (44 %) had coronary plaque detectable on CTA, and 38 (39 %) had CAC score >0. By CTA, 16 (16 %) had coronary stenosis ≥50 %, including three subjects with CAC = 0. Subjects with coronary plaque had greater prevalence of carotid plaque (58 % vs. 38 %, p = 0.01) and greater carotid intima media thickness (0.80 ± 0.20 mm vs. 0.70 ± 0.11 mm, p = 0.02). Notably, 18 of 55 subjects (33 %) with normal CTA had carotid plaque. Eight subjects had a positive ETT, of whom five had ≥ 50 % coronary stenosis, two had <50 % stenosis, and one had no CAD. Among these tests, CAC scoring had the highest sensitivity and specificity for prediction of CAD.

Conclusion

Among asymptomatic subjects with T2DM, a majority (56 %) had no CAD by CTA. When compared to CTA, CAC was the most accurate screening modality for detection of CAD, while ETT and carotid ultrasound were less sensitive and specific. However, 33 % of subjects with normal coronary CTA had carotid plaque, suggesting that screening for carotid plaque might better characterize stroke risk in such patients.

Prognostic value of coronary computed tomography angiography in diabetic patients without chest pain syndrome

AIMS

Diabetic patients with coronary artery disease (CAD) are often free of chest pain syndrome. A useful modality for non-invasive assessment of CAD is coronary computed tomography angiography (CTA). However, the prognostic value of CAD on coronary CTA in diabetic patients without chest pain syndrome is relatively unknown. Therefore, the aim was to investigate the long-term prognostic value of coronary CTA in a large population diabetic patients without chest pain syndrome.

METHODS

Between 2005 and 2013, 525 diabetic patients without chest pain syndrome were prospectively included to undergo coronary artery calcium (CAC)-scoring followed by coronary CTA. During follow-up, the composite endpoint of all-cause mortality, non-fatal myocardial infarction (MI), and late revascularization (>90 days) was registered.

RESULTS

In total, CAC-scoring was performed in 410 patients and coronary CTA in 444 patients (431 interpretable). After median follow-up of 5.0 (IQR 2.7-6.5) years, the composite endpoint occurred in 65 (14%) patients. Coronary CTA demonstrated a high prevalence of CAD (85%), mostly non-obstructive CAD (51%). Furthermore, patients with a normal CTA had an excellent prognosis (event-rate 3%). An incremental increase in event-rate was observed with increasing CAC-risk category or coronary stenosis severity. Finally, obstructive (50-70%) or severe CAD (>70%) was independently predictive of events (HR 11.10 [2.52;48.79] (P = .001), HR 15.16 [3.01;76.36] (P = .001)). Obstructive (50-70%) or severe CAD (>70%) provided increased value over baseline risk factors.

CONCLUSION

Coronary CTA provided prognostic value in diabetic patients without chest pain syndrome. Most importantly, the prognosis of patients with a normal CTA was excellent.

Prognostic Value of Renal Function for Cardiac Events in Patients Without Significant Stenosis on Coronary Computed Tomography Angiography

This study was conducted to determine clinical parameters predicting future major adverse cardiovascular events (MACEs) in patients without significant stenosis on coronary computed tomographic angiography (CCTA). A total of 625 patients with suspected coronary artery disease (CAD) who underwent CCTA that revealed insignificant (< 50%) CAD was reviewed in three cardiac centers. The MACEs including cardiac death, non-fatal myocardial infarction (MI), unstable angina and late (> 90 days after CCTA) revascularization were assessed. During the mean follow-up period of 819 ± 529 days (median 837 days), there were 28 cases of MACEs (4.5%). In multivariable Cox regression analysis, independent predictors for MACEs were male sex (hazard ratio [HR], 2.40; 95% confidence interval [CI], 1.01-5.69; P = 0.046) and low estimated creatinine clearance (eCCr) (< 60 mL/min/1.73 m(2)) (HR, 3.07; 95% CI, 1.22-7.74; P = 0.017). Low eCCr was the only independent predictor for hard events including cardiac death and MI (HR, 17.6, 95% CI, 1.44-215.7; P = 0.025). In conclusion, renal function is an independent predictor for cardiovascular events among patients without significant CAD by CCTA. Careful monitoring and preventive strategy are warranted in patients with impaired renal function even without significant CAD.

Presence and extent of coronary calcified plaque evaluated by coronary computed tomographic angiography are independent predictors of ischemic stroke in patients with suspected coronary artery disease

Although ischemic stroke and coronary artery disease (CAD) share common risk factors and pathophysiology, the risk of stroke in patients with CAD remains unclear. We sought to evaluate the risk of ischemic stroke in patients with suspected CAD according to coronary computed tomographic angiography (CCTA) and single-photon emission computed tomography (SPECT) findings. Presence, severity, and extent of CAD were evaluated in 1137 patients with suspected CAD who underwent CCTA and SPECT. Primary outcome was the occurrence of ischemic stroke. During follow-up (median 26 months), ischemic stroke was observed in 25 patients (2.2%). The presence of coronary plaque on CCTA was associated with the occurrence of ischemic stroke (2.8 vs. 0.6%; p = 0.029), while the presence of PD on SPECT was not (2.0 vs. 2.3%; p = 0.768). Stroke occurrence was not increased by the presence of significant stenosis of ≥50% DS (2.8%; p = 0.943), but was further increased by the plaque presence in ≥2 vessels (6.1 %; p = 0.001) or ≥3 segments (4.1%; p = 0.019). Presence of calcified plaque, and calcified plaque in ≥2 segments were also associated with ischemic stroke occurrence (4.3%; p < 0.001, and 5.6%; p < 0.001, respectively) and were the independent risk factors when adjusted to age of ≥65, hypertension, presence of any coronary plaque and plaque in ≥3 segments (adjusted HR 6.09; 95% CI 1.38-26.87; p = 0.017, and adjusted HR 5.47; 95% CI 1.85-16.19; p = 0.002, respectively). The risk of ischemic stroke was associated with the presence and extent of coronary atherosclerotic plaque evaluated by CCTA, but not with the presence and extent of myocardial ischemia evaluated by SPECT. Especially, calcified coronary plaque presence and extent were the independent predictors of ischemic stroke and allowed further risk stratification.

Identification of coronary heart disease in asymptomatic individuals with diabetes mellitus: to screen or not to screen

Coronary heart disease (CHD) is highly prevalent in patients with diabetes mellitus (DM), and remains the single most common cause of death among this population. Regrettably, a significant percentage of diabetics fail to perceive the classic symptoms associated with myocardial ischemia. Among asymptomatic diabetics, the prevalence of abnormal cardiac testing appears to be high, ranging between 10% and 62%, and mortality is significantly higher in those with abnormal scans. Hence, the potential use of screening for CHD detection among asymptomatic DM individuals is appealing and has been recommended in certain circumstances. However, it was not until recently, that this question was addressed in clinical trials. Two studies randomized a total of 2,023 asymptomatic diabetics to screening or not using cardiac imaging with a mean follow up of 4.4 ± 1.4 years. In combination, both trials showed lower than expected annual event rates, and failed to reduce major cardiovascular events in the screened group compared to the standard of care alone. The results of these trials do not currently support the use of screening tools for CHD detection in asymptomatic DM individuals. However, these studies have important limitations, and potential explanations for their negative results that are discussed in this manuscript.

Cost-effectiveness of coronary CT angiography in patients with chest pain: Comparison with myocardial single photon emission tomography

BACKGROUND

Coronary CT angiography (CCTA) has been proven accurate and is incorporated in clinical recommendations for coronary artery disease (CAD) diagnosis workup, but cost-effectiveness data, especially in comparison to other methods such as myocardial single photon emission CT (SPECT) are insufficient.

OBJECTIVE

To compare the cost-effectiveness of CCTA and myocardial SPECT in a real-world setting.

METHODS

We performed a retrospective cohort study on consecutive patients with suspected CAD and a pretest probability between 10% and 90%. Test accuracy was compared by correcting referral bias to coronary angiography depending on noninvasive test results based on the Bayes' theorem and also by incorporating 1-year follow-up results. Cost-effectiveness was analyzed using test accuracy and quality-adjusted life year (QALY). The model using diagnostic accuracy used the number of patients accurately diagnosed among 1000 persons as the effect and contained only expenses for diagnostic testing as the cost. In the model using QALY, a decision tree was developed, and the time horizon was 1 year.

RESULTS

CCTA was performed in 635 patients and SPECT in 997 patients. An accurate diagnosis per 1000 patients was achieved in 725 patients by CCTA vs 661 patients by SPECT. In the model using diagnostic accuracy, CCTA was more effective and less expensive than SPECT ($725.38 for CCTA vs $661.46 for SPECT). In the model using QALY, CCTA was generally more effective in terms of life quality (0.00221 QALY) and cost ($513) than SPECT. However, cost utility varied among subgroups, with SPECT outperforming CCTA in patients with a pretest probability of 30% to 60% (0.01890 QALY; $113).

CONCLUSION

These results suggest that CCTA may be more cost-effective than myocardial SPECT.

Coronary computed tomography angiography alone versus confirmatory functional testing for guiding treatment strategy for patients with intermediate coronary artery stenosis

Intermediate coronary artery stenosis (≥50% and <90%) on coronary computed tomography angiography (CTA) is usually considered as a significant lesion. However, anatomical diagnosis is not well correlated with the functional significance of myocardial ischemia. We investigated whether functional testing in addition to coronary CTA improves outcomes of patients with intermediate stenosis, compared with the 1-step CTA-alone-based strategy. From 2006 to 2011, we consecutively enrolled 335 patients with chest pain with intermediate stenosis detected by an initially performed coronary CTA. Of these, 159 patients followed the 1-step strategy, whereas 176 followed the 2-step strategy with confirmatory functional tests. One-year follow-up data were obtained for all patients. The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, and repeated or delayed revascularization (major adverse cardiac event) within a year. Baseline clinical parameters were comparable between patients of the 2 different strategies. The rate of invasive catheterization or percutaneous intervention was 75.5% in the 1-step group and 35.2% in the 2-step group (p <0.001). Consequently, more patients in the 2-step group were medically treated without unnecessary revascularization compared with patients in the 1-step group (71.0% vs 40.9%, p <0.001). Only 2.5% of the patients who received medical treatment in the 2-step group finally received delayed revascularization, whereas 14% in the 1-step group did. Overall, the primary end point occurred in 11.3% in the 1-step group and 4.0% in the 2-step group (p = 0.011). In conclusion, confirmatory functional testing reduces invasive catheterization and coronary intervention and improves clinical outcomes in patients with intermediate stenosis on coronary CTA.

Silent myocardial ischemia detected by single photon emission computed tomography (SPECT) and risk of cardiac events among asymptomatic patients with type 2 diabetes: a meta-analysis of prospective studies

OBJECTIVE

To assess the value of detecting silent myocardial ischemia (SMI) by single photon emission computed tomography (SPECT) in predicting risk of cardiac events among patients with type 2 diabetes mellitus (T2DM) who do not have overt cardiac symptoms.

MATERIALS AND METHODS

Electronic databases (PubMed, Cochrane Library, EMBASE, and others) and original article references were systematically searched through February 1, 2013. A fixed-effects model was applied to pooled data to estimate relative risks (RR) and 95% confidence intervals (CI).

RESULTS

Ten prospective studies with follow-up ranging from 1 to 6 years were identified. Among the total of 1360 asymptomatic patients with T2DM screened by SPECT, the cumulative prevalence rate of SMI was 26.1%. Patients with SMI were at increased risk of experiencing endpoints relative to patients without SMI: RR (95% CI) for cardiac death, 4.60 (1.78-11.84); non-fatal cardiac events, 3.48 (2.30-5.28); total cardiac events, 3.48 (2.59-4.68); and all-cause mortality, 2.20 (1.14-4.25). The risk of cardiac death and non-fatal cardiac events increased with increasing severity of SPECT-detected abnormalities.

CONCLUSIONS

SMI detected by SPECT is associated with increased risk of cardiac death, all-cause mortality, and non-fatal cardiac events in T2DM patients without overt cardiac symptoms. Advanced intervention procedures including intensive drug management should be implemented to reduce the risk of cardiac events for SMI-positive T2DM patients.

Asymptomatic subjects with diabetes have a comparable risk of coronary artery disease to non-diabetic subjects presenting chest pain: a 4-year community-based prospective study

BACKGROUND

Although diabetes mellitus is an important risk factor of coronary artery disease (CAD), routine screening for CAD is not recommended for asymptomatic diabetic patients. We assessed the impact of chest pain on CAD risk according to the presence or absence of diabetes mellitus.

METHODS

We investigated the future CAD event rate in subjects with and without chest pain according to the presence or absence of diabetes in a prospective large-scale community-based study in Korea.

RESULTS

Among 8,574 subjects (4,032 men and 4,542 women) without a history of CAD, 0.8% and 2.2% of non-diabetic and diabetic subjects, respectively, reported newly developed CAD events during 4 years of follow-up. Although the presence of chest pain at baseline was also significantly associated with an increased risk of CAD of more than 2-fold in both non-diabetic and diabetic subjects (P < 0.01), the risk of future CVD event in asymptomatic diabetic patients was not significantly different from that in non-diabetic subjects with chest pain (hazard ratio, 0.907; 95% confidence interval, 0.412 - 1.998).

CONCLUSIONS

The CAD event rate of asymptomatic subjects with diabetes was comparable to that of non-diabetic subjects reporting chest pain. Considering the high risk of CAD in asymptomatic diabetic patients, more clinical trials aimed at formulating strategies to screen asymptomatic diabetic subjects should be carried out.

Gender differences in myocardial perfusion defect in asymptomatic postmenopausal women and men with and without diabetes mellitus

BACKGROUND

To compare the results of myocardial perfusion imaging (MPI) of asymptomatic postmenopausal women and age-matched men and to investigate the effect of diabetes mellitus (DM) on gender differences and the risk estimation of coronary heart disease (CHD).

METHODS

Sixty-seven postmenopausal women and 27 men low in Framingham Global Risk Score (FGRS) were recruited from year 2008 to 2009 in northern Taiwan. Each subject underwent blood tests, a cardiopulmonary exercise test, an electrocardiograph (ECG), and MPI.

RESULTS

Women had similar percentages of predicted oxygen consumption and ECG changes at peak exercise, but lower oxygen pulse and rate-pressure product. They also had significantly higher summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) than men, despite showing much lower scores for the FGRS than men. Women with DM had a lower 10-year risk of CHD assessed by the United Kingdom Prospective Diabetes Study (UKPDS) risk engine, but significantly higher SSS and SDS than men. In the subjects with abnormal MPI, the extent of ischemia was small to moderate in men, whereas in 50% of the women, the extent of ischemia was large.

CONCLUSION

The results of this preliminary study suggest that asymptomatic postmenopausal women had more abnormalities in MPI and those with DM had a higher SSS and SDS than age-matched men. The risk of CAD may still be underestimated by the UKPDS.

Prognostic value of myocardial perfusion imaging for cardiovascular events among asymptomatic Japanese patients with type 2 diabetes and mild renal dysfunction

BACKGROUND

Diabetes is frequently accompanied by chronic kidney disease, and both diabetes and chronic kidney disease are risk factors for ischemic heart disease; however, cardiac risk among diabetic patients with mild renal dysfunction has not been analyzed in detail. The present study investigates how myocardial perfusion imaging (MPI) contributes to the risk stratification of diabetic patients with mild renal dysfunction who are asymptomatic for cardiac diseases.

PATIENTS AND METHODS

Among 513 asymptomatic patients with type 2 diabetes in the Japanese Assessment of Cardiac Events and Survival Study 2 (J-ACCESS) database, we selected 286 with estimated glomerular filtration rates (eGFR) of at least 45 ml/min/1.73 m and assigned them to groups on the basis of eGFR of at least 60 without (group A, n=66) or with microalbuminuria or eGFR 45 to less than 60 (group B, n=220). The 3-year incidence of cardiac events and the value of MPI were evaluated.

RESULTS

Cardiac events developed in 1.52 and 4.55% of patients in groups A and B, respectively. Event-free survival did not differ according to summed stress scores in group A but was significantly lower among patients with summed stress scores of at least 9 in group B.

CONCLUSION

Routine MPI might be useful for stratifying risk among diabetic patients with mild renal dysfunction but is unnecessary for those with good renal function.

Association between EPCs count and rate of coronary revascularization in asymptomatic type 2 diabetic patients

Coronary arterial disease (CAD) is common in diabetic patients, and endothelial progenitor cells (EPCs) are considered a surrogate marker for CAD, but controversies regarding this issue still remain. We investigated the potential clinical role of EPCs during coronary screening in asymptomatic type 2 diabetic patients screened with cardiovascular magnetic resonance (CMR). A total of 100 asymptomatic type 2 diabetic subjects (51 men and 49 women) were enrolled. Clinical and laboratory parameters, including EPCs (CD34(+)/CD133(+)/VEGFR-2(+)) count, were evaluated and CMR was performed. A total of 51 patients [silent myocardial infarction (n = 3), inducible ischemia (n = 11), suspected CAD (n = 37)] had abnormal finding on CMR. Of the 20 patients who later underwent invasive coronary angiography, 8 were treated with revascularization. Fifty-one subjects with abnormal finding on CMR were divided into two groups [subjects with revascularization (group I, n = 8) vs. without revascularization (group II, n = 43)]. Group I had a significantly increased EPCs level than group II (833 vs. 415, P = 0.027). Multivariate logistic regression analysis revealed that an increased EPCs level (OR = 1.003, P = 0.024) and a high body-mass index (OR = 1.907, P = 0.028) were independently correlated with revascularization. In our study, increased EPCs count is associated with performing revascularization in asymptomatic type 2 diabetic patients, and that increased EPCs count can provide clinically important information while performing intervention.

Usefulness of albuminuria as predictor for coronary artery stenosis, regardless of estimated glomerular filtration rate, in patients with type 2 diabetes mellitus

The aim of the present study was to evaluate the independent predictors of coronary artery stenosis in patients with type 2 diabetes mellitus (DM) and subclinical atherosclerosis. A total of 232 patients with type 2 DM and subclinical atherosclerosis underwent multislice computed tomography coronary angiography. Subclinical atherosclerosis was determined by the carotid intima-media thickness (IMT) or carotid plaque. Multislice computed tomography coronary angiography revealed significant coronary stenosis (>50% in diameter) in 71 subjects (31%). The subjects who had significant coronary stenosis were much older and had had a longer duration of DM. In particular, the log-transformed albumin/creatinine ratio (ACR) was greater in the subjects with significant coronary stenosis compared to the subjects without significant coronary stenosis. The age- and gender-adjusted odds ratio for significant coronary stenosis increased in proportion to albuminuria with a given estimated glomerular filtration rate. The ACR as a continuous variable (odds ratio 4.167, 95% confidence interval 1.497 to 11.599) or categorical variable (ACR >30 μg/mg, odds ratio 4.619, 95% confidence interval 1.562 to 13.659) was associated with an increased risk of significant coronary stenosis, independent of conventional cardiovascular risk factors. In receiver operating characteristic analysis, the ACR had an additive effect with carotid IMT for predicting significant coronary stenosis (area under the curve 0.625 with carotid IMT; area under the curve 0.710 with carotid IMT plus ACR, p = 0.0144). In conclusion, the presence of albuminuria is an independent predictor for significant coronary stenosis in patients with type 2 DM and subclinical atherosclerosis.

Identification of noncalcified plaque in young persons with diabetes: an opportunity for early primary prevention of coronary artery disease identified with low-dose coronary computed tomographic angiography

PURPOSE

Coronary computed tomographic angiography (CTA) is a valuable tool for assessing coronary artery disease (CAD). Although statin use is widely recommended for persons with diabetes older than age 40, little is known about the presence and severity of CAD in younger patients with diabetes mellitus (DM). We evaluated coronary artery calcium (CAC) and coronary CTA in young persons with both DM1 and DM2 in an attempt to detect the earliest objective evidence of arteriosclerosis eligible for primary prevention.

METHODS AND MATERIALS

We prospectively enrolled 40 persons with DM (25 type 1 and 15 type 2) between the ages of 19 and 35 presenting with diabetes for 5 years or longer. All patients underwent coronary CTA and CAC scans to evaluate for early atherosclerotic disease. Each plaque in the coronary artery was classified as noncalcified or calcified-mixed. We also evaluated all segments with stenosis, dividing them into mild (<50%), moderate (50-70%), and severe (>70%).

RESULTS

The average age of the DM1 subjects were 26 ± 4 (SD) years and 30 ± 4 years for DM2 patients (P < .01), with duration of diabetes of 8 ± 5 years and average HbA1c% of 8.7 ± 1.6 (norm = 4.6-6.2). Abnormal scans were present in 57.5%, noncalcified in 35% and calcified-mixed plaque in 22.5%. Persons with DM2 had a higher prevalence of positive coronary CTA scans than DM1: 80% versus 44% (P < .03) and more positive CAC scores 53% versus 4%, (P < .01). The total segment score of 2.1 ± 3.4 (P < .01) and total plaque score 1.9 ± 2.8 (P < .01) were highly correlated to each other. Plaque was almost uniformly absent below age 25, and became increasingly common in individuals over the age of 25 years for both groups. The average radiation exposure was 2.5 ± 1.3 mSv.

CONCLUSION

Our study verifies that early CAD can be diagnosed with coronary CTA and minimal radiation exposure in young adults with DM. A negative CAC score was not sufficient to exclude early CAD as we observed a preponderance of noncalcified plaque in this cohort. Coronary CTA in young DM patients older than age 25 may provide earlier identification of disease than does a CAC because only noncalcified plaque is frequently present. Coronary CTA provides an opportunity to consider initiation of earlier primary CAD prevention rather than waiting for the age of 40 as currently recommended by the American Diabetes Association guidelines.

A novel biomarker of coronary atherosclerosis: serum DKK1 concentration correlates with coronary artery calcification and atherosclerotic plaques

DKK1 modulates Wnt signaling, which is involved in the atherosclerosis. However, no data exist regarding the usefulness of measuring serum DKK1 concentration in predicting coronary atherosclerosis. A total of 270 consecutive patients (62.8 ± 11.2 yr; 70% male) were included. A contrast-enhanced 64-slice coronary MDCT was performed to identify the presence of atherosclerotic plaques. Agatston calcium scores (CS) were calculated to quantify the coronary artery calcification (CAC). DKK1 concentrations were measured by enzyme-linked immunosorbent assay. For each subsequent DKK1 quartile, there was a significant increase in CAC (P = 0.004) and the number of segments with coronary atherosclerosis (P < 0.001). In addition, DKK1 concentration was significantly higher in patients with atherosclerotic plaques, regardless of plaque composition (P = 0.01). Multivariate analysis identified DKK1 as an independent risk factor for the presence of coronary atherosclerotic plaque. The adjusted odds ratio for coronary atherosclerotic plaque was 4.88 (95% CI, 1.67 to 14.25) for highest versus lowest quartile of the DKK1 levels. Furthermore, patients with DKK1 concentrations ≥ 68.6 pg/mL demonstrated coronary atherosclerotic plaques even when they had low CS. Serum DKK1 concentrations correlate with the coronary atherosclerosis and play an independent role in predicting the presence of coronary atherosclerosis.

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.