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

Differential Impact of Degree of Hypertension on Subclinical Coronary Atherosclerosis in Asymptomatic Subjects With and Without Diabetes Mellitus

This study sought to evaluate the association between the degree of hypertension and subclinical coronary atherosclerosis in asymptomatic subjects with and without diabetes mellitus (DM). We retrospectively analyzed 7,352 asymptomatic subjects (mean age 52.8 ± 7.8 years; 4,689 [63.8%] men) with no history of coronary artery disease who voluntarily underwent coronary computed tomography angiography as part of a general health examination. The classification of hypertension was adapted from the American College of Cardiology and American Heart Association 2017 guideline. Subclinical coronary atherosclerosis was defined as the presence of coronary plaque by coronary computed tomography angiography. In subjects without DM (n = 6,598), after the adjustment for cardiovascular risk factors, subclinical coronary atherosclerosis was significantly associated with both stage 1 hypertension (adjusted odds ratio [aOR] 1.356; 95% confidence interval [CI], 1.167 to 1.575; p <0.001) and stage 2 hypertension (aOR, 1.614; 95% CI, 1.329 to 1.961; p <0.001) groups compared with the normal group. In contrast, in subjects with DM (n = 754), there was no statistical difference in the aOR of the stage 1 hypertension group for the presence of coronary plaque (aOR, 1.449; 95% CI, 0.982 to 2.136; p = 0.061). However, the stage 2 hypertension group had a significant association with subclinical coronary atherosclerosis (aOR, 2.067; 95% CI, 1.287 to 3.322; p = 0.003). In subjects without DM, both stages 1 and 2 hypertension were associated with subclinical coronary atherosclerosis. However, in subjects with DM, stage 2 hypertension was only associated with an increased risk of subclinical coronary atherosclerosis.

Added Prognostic Value of Plaque Burden to Computed Tomography Angiography and Myocardial Perfusion Imaging in Patients with Diabetes

BACKGROUND

We aimed to compare the added prognostic value of plaque burden to cardiac computed tomographic angiography (CCTA) anatomic assessment and single-photon emission computed tomography (SPECT) physiologic assessment in patients with diabetes undergoing both tests.

METHODS

Consecutive patients with diabetes who underwent clinically indicated CCTA and SPECT myocardial imaging for suspected coronary artery disease were included. Stenosis severity and segment involvement score (SIS) were determined from CCTA, and presence of ischemia was determined from SPECT. Patients were followed from date of imaging for major adverse cardiovascular events (MACE).

RESULTS

A total of 778 patients were included (mean age 60.6 ± 14.4 years, 55% males). After a median follow-up of 31 months, 87 (11%) patients experienced a MACE. In multivariable Cox regression models, SIS significantly predicted outcomes in models including obstructive stenosis and ischemia (hazard ratio 1.17, 95% confidence interval 1.10-1.24, P < .001; hazard ratio 1.16, 95% confidence interval 1.10-1.23, P < .001, respectively), and improved discrimination (Harrel's C 0.75, P = .006; 0.76, P = .006 in models with CCTA obstructive stenosis and SPECT ischemia, respectively). Results were consistent using subgroups of summed scores by composition of plaque (calcified vs noncalcified) and alternate definitions of obstructive stenosis.

CONCLUSION

Our results suggest that in high-risk patients with diabetes and suspected coronary disease, SIS has incremental prognostic value over ischemia by SPECT or stenosis by CCTA in predicting incident cardiovascular outcomes.

Higher prevalence of incidental findings identified upon coronary calcium score assessment in type 2 and type 3 diabetes versus type 1 diabetes

Aim

Noninvasive assessment of infraclinic coronary atherosclerosis by coronary artery calcium score (CAC) measurement leads to the identification of incidental findings. The aim of this study was to determine the prevalence of incidental findings following systematic CAC assessment in diabetic patients with high cardiovascular risk, to identify the determinants, and to assess the midterm consequences of these findings in patient care.

Methods

732 consecutive asymptomatic patients (187 type 1 diabetes (TD1), 482 type 2 diabetes (TD2) and 63 type 3 diabetes (TD3)) aged 60.6±0.7 years who had a CAC assessment by Multiple Detector Computed Tomography between 2015 and 2017 were systematically included. Clinical and biological data were collected from medical electronic files.

Results

117/732 diabetic patients (16.0%) had incidental findings of which 105 (14.3%) were unknown. Incidental findings were more frequent in TD3 (23.8%) and TD2 (17.0%) than in TD1 (10.7%) (p = 0.05). 76 diabetic patients (10.4%) had lung abnormalities, mainly pulmonary nodules (31 patients, 4.2%). The other incidental finding were pericardial (1.5%), vascular (1.2%), thymic (0.7%) and digestive diseases (0.5%). 42.6% of patients with incidental findings had an additional TDM and 56.8% a specialized medical advice. In 10 patients (9.3% of incidental findings), the identification of incidental finding led to a specific treatment of the underlying disease. In multivariate analysis, microalbuminuria, type of diabetes (TD2/TD3 vs TD1) and smoking were significantly associated with incidental findings (p = 0.003; p = 0.026; p = 0.050 respectively).

Conclusions

Incidental findings are not rare in diabetic patients upon CAC assessment. A fraction of them are accessible to specific treatment. These findings raise the question if a systematic low dose chest TDM should be conducted in TD2 or TD3 patients and in any diabetic smokers by enlarging the window used for CAC assessment.

Society of Cardiovascular Computed Tomography / North American Society of Cardiovascular Imaging - Expert Consensus Document on Coronary CT Imaging of Atherosclerotic Plaque

Coronary computed tomographic angiography (CCTA) provides a wealth of clinically meaningful information beyond anatomic stenosis alone, including the presence or absence of nonobstructive atherosclerosis and high-risk plaque features as precursors for incident coronary events. There is, however, no uniform agreement on how to identify and quantify these features or their use in evidence-based clinical decision-making. This statement from the Society of Cardiovascular Computed Tomography and North American Society of Cardiovascular Imaging addresses this gap and provides a comprehensive review of the available evidence on imaging of coronary atherosclerosis. In this statement, we provide standardized definitions for high-risk plaque (HRP) features and distill the evidence on the effectiveness of risk stratification into usable practice points. This statement outlines how this information should be communicated to referring physicians and patients by identifying critical elements to include in a structured CCTA report - the presence and severity of atherosclerotic plaque (descriptive statements, CAD-RADS™ categories), the segment involvement score, HRP features (e.g., low attenuation plaque, positive remodeling), and the coronary artery calcium score (when performed). Rigorous documentation of atherosclerosis on CCTA provides a vital opportunity to make recommendations for preventive care and to initiate and guide an effective care strategy for at-risk patients.

Prognostic Value of Atherosclerotic Extent in Diabetic Patients with Nonobstructive Coronary Artery Disease

METHODS AND RESULTS

813 DM patients (mean age 58.9 ± 9.9 years, 48.1% male) referred for CCTA due to suspected CAD in 2015-2017 were consecutively included. During a median follow-up of 31.77 months, 50 major adverse cardiovascular events (MACEs) (6.15%) were experienced, including 2 cardiovascular deaths, 14 nonfatal myocardial infarctions, 27 unstable anginas requiring hospitalization, and 7 strokes. Three groups were defined based on coronary stenosis combined with Leiden score as normal, nonobstructive Leiden < 5, and nonobstructive Leiden ≥ 5. Cox models were used to assess the prognosis of plaque burden within these groups. An incremental incidence of MACE rates was observed. After adjustment for age, gender, and presence of high-risk plaque, the group of Leiden ≥ 5 showed a higher risk than Leiden < 5 (HR: 1.88, 95% CI: 1.03-3.42, p = 0.039). Similar results were observed when segment involvement score (SIS) was used for sensitivity analysis.

CONCLUSION

Atherosclerotic extent was associated with the prognosis of DM patients with nonobstructive coronary artery disease, highlighting the importance of better risk stratification and management.

Risk stratification by assessment of coronary artery disease using coronary computed tomography angiography in diabetes and non-diabetes patients: a study from the Western Denmark Cardiac Computed Tomography Registry

AIMS

We examined whether severity of coronary artery disease (CAD) measured by coronary computed tomography angiography can be used to predict rates of myocardial infarction (MI) and death in patients with and without diabetes.

METHODS AND RESULTS

A cohort study of consecutive patients (n = 48 731) registered in the Western Denmark Cardiac Computed Tomography Registry from 2008 to 2016. Patients were stratified by diabetes status and CAD severity (no, non-obstructive, or obstructive). Endpoints were MI and death. Event rates per 1000 person-years, unadjusted and adjusted incidence rate ratios were computed. Median follow-up was 3.6 years. Among non-diabetes patients, MI event rates per 1000 person-years were 1.4 for no CAD, 4.1 for non-obstructive CAD, and 9.1 for obstructive CAD. Among diabetes patients, the corresponding rates were 2.1 for no CAD, 4.8 for non-obstructive CAD, and 12.6 for obstructive CAD. Non-diabetes and diabetes patients without CAD had similar low rates of MI [adjusted incidence rate ratio 1.40, 95% confidence interval (CI): 0.71-2.78]. Among diabetes patients, the adjusted risk of MI increased with severity of CAD (no CAD: reference; non-obstructive CAD: adjusted incidence rate ratio 1.71, 95% CI: 0.79-3.68; obstructive CAD: adjusted incidence rate ratio 4.42, 95% CI: 2.14-9.17). Diabetes patients had higher death rates than non-diabetes patients, irrespective of CAD severity.

CONCLUSION

In patients without CAD, diabetes patients have a low risk of MI similar to non-diabetes patients. Further, MI rates increase with CAD severity in both diabetes and non-diabetes patients; with diabetes patients with obstructive CAD having the highest risk of MI.

Prognostic value of cardiac CT

In the past decades, coronary computed tomography angiography (CCTA) has become a powerful tool in the management of coronary artery disease. The diagnostic and prognostic value of CCTA has been extensively demonstrated in both large observational studies and clinical trials among stable chest pain patients. The quantification of coronary artery calcium score (CACS) is a well-established predictor of cardiovascular morbidity and mortality in asymptomatic subjects. Besides CACS, the main strength of CCTA is the accurate assessment of the individual total atherosclerotic plaque burden, which holds important prognostic information. In addition, CCTA, by providing detailed information on coronary plaque morphology and composition with identification of specific high-risk plaque features, may further improve the risk stratification beyond the assessment of coronary stenosis. The development of new CCTA applications, such as stress myocardial CT perfusion and computational fluids dynamic applied to standard CCTA to derive CT-based fractional flow reserve (FFR) values have shown promising results to guide revascularization, potentially improving clinical outcomes in stable chest pain patients. In this review, starting from the role of CACS and moving beyond coronary stenosis, we evaluate the existing evidence of the prognostic effectiveness of the CCTA strategy in real-world clinical practice.

Impact of Diabetes Control on Subclinical Atherosclerosis: Analysis from Coronary Computed Tomographic Angiography Registry

BACKGROUND

There are limited data on the impact of diabetes control on the risk of subclinical coronary atherosclerosis.

METHODS

We analyzed 6,434 consecutive asymptomatic individuals without previous history of coronary artery disease who underwent coronary computed tomographic angiography (CCTA) (mean age, 53.7±7.6 years and 4,694 men [73.0%]). The degree and extent of subclinical coronary atherosclerosis were assessed by CCTA, and ≥50% diameter stenosis was defined as significant. A cardiac event was defined as a composite of all-cause death, myocardial infarction, unstable angina, or coronary revascularization. Study participants were categorized as normal (n=5,319), controlled diabetes (glycosylated hemoglobin [HbA1c] <7%, n=747), or uncontrolled diabetes (HbA1c ≥7%, n=368), respectively.

RESULTS

Compared with normal individuals, there were no statistically significant differences in the risk of for any atherosclerotic plaque (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.98 to 1.38; P=0.086) and significant coronary artery stenosis (OR, 1.08; 95% CI, 0.82 to 1.42; P=0.583) in controlled diabetic individuals. In contrast, uncontrolled diabetic individuals had consistently higher risks of any atherosclerotic plaque (OR, 2.16; 95% CI, 1.70 to 2.75; P<0.001) and significant coronary artery stenosis (OR, 3.34; 95% CI, 2.52 to 4.43; P<0.001) than normal individuals. During a follow-up of median 5.4 years, there was no significant difference in cardiac events between normal and controlled diabetic individuals (P=0.365). However, uncontrolled diabetes was associated with an increased risk of cardiac events compared with normal individuals (P<0.001) and controlled diabetic individuals (P=0.023).

CONCLUSION

Asymptomatic uncontrolled diabetes was associated with significant subclinical coronary atherosclerosis with subsequent high risk for cardiac events.

Coronary atherosclerosis scoring with semiquantitative CCTA risk scores for prediction of major adverse cardiac events: Propensity score-based analysis of diabetic and non-diabetic patients

AIMS

We aimed to compare semiquantitative coronary computed tomography angiography (CCTA) risk scores - which score presence, extent, composition, stenosis and/or location of coronary artery disease (CAD) - and their prognostic value between patients with and without diabetes mellitus (DM). Risk scores derived from general chest-pain populations are often challenging to apply in DM patients, because of numerous confounders.

METHODS

Out of a combined cohort from the Leiden University Medical Center and the CONFIRM registry with 5-year follow-up data, we performed a secondary analysis in diabetic patients with suspected CAD who were clinically referred for CCTA. A total of 732 DM patients was 1:1 propensity-matched with 732 non-DM patients by age, sex and cardiovascular risk factors. A subset of 7 semiquantitative CCTA risk scores was compared between groups: 1) any stenosis ≥50%, 2) any stenosis ≥70%, 3) stenosis-severity component of the coronary artery disease-reporting and data system (CAD-RADS), 4) segment involvement score (SIS), 5) segment stenosis score (SSS), 6) CT-adapted Leaman score (CT-LeSc), and 7) Leiden CCTA risk score. Cox-regression analysis was performed to assess the association between the scores and the primary endpoint of all-cause death and non-fatal myocardial infarction. Also, area under the receiver-operating characteristics curves were compared to evaluate discriminatory ability.

RESULTS

A total of 1,464 DM and non-DM patients (mean age 58 ± 12 years, 40% women) underwent CCTA and 155 (11%) events were documented after median follow-up of 5.1 years. In DM patients, the 7 semiquantitative CCTA risk scores were significantly more prevalent or higher as compared to non-DM patients (p ≤ 0.022). All scores were independently associated with the primary endpoint in both patients with and without DM (p ≤ 0.020), with non-significant interaction between the scores and diabetes (interaction p ≥ 0.109). Discriminatory ability of the Leiden CCTA risk score in DM patients was significantly better than any stenosis ≥50% and ≥70% (p = 0.003 and p = 0.007, respectively), but comparable to the CAD-RADS, SIS, SSS and CT-LeSc that also focus on the extent of CAD (p ≥ 0.265).

CONCLUSION

Coronary atherosclerosis scoring with semiquantitative CCTA risk scores incorporating the total extent of CAD discriminate major adverse cardiac events well, and might be useful for risk stratification of patients with DM beyond the binary evaluation of obstructive stenosis alone.

Screening for Atherosclerotic Cardiovascular Disease in Patients With Type 2 Diabetes Mellitus: Controversies and Guidelines

If a disease state is highly prevalent and its consequences are severe, it may be appropriate to seek methods to identify it early to forestall its development and complications. Diabetes mellitus is a proven risk factor for the development of atherosclerosis, although its face and outcome are changing, as shown in contemporary clinical trials. In fact, decompensated heart failure seems to drive the hospitalization rate in patients with diabetes, and mortality from heart failure is reduced with modern hypoglycemic treatments. Nonetheless, atherosclerotic complications continue to be a major health concern in this segment of the population and cardiovascular imaging has been employed in an attempt to achieve a more accurate risk stratification. Although imaging for detection of obstructive coronary artery disease failed to reach such a goal, imaging for preclinical atherosclerosis may be more successful. In this review, we discuss the use of computed tomography and positron emission tomography to detect preclinical coronary atherosclerosis in asymptomatic patients with diabetes. Despite recent advances in the field, several questions remain to be answered as to the ultimate benefit of imaging for prevention in diabetes mellitus.

Association between anti-diabetes treatments and cardiovascular risk in diabetes patients with and without coronary artery disease

OBJECTIVE

We examined the risk of myocardial infarction associated with glucose-lowering therapy among diabetes patients with and without obstructive coronary artery disease.

METHODS

A cohort of patients with type 1 or type 2 diabetes (n = 12,030), who underwent coronary angiography from 2004 to 2012, were stratified by presence of obstructive (any stenosis ⩾50%) coronary artery disease and by type of diabetes treatment: diet, non-insulin treatment and insulin (±oral anti-diabetics). The primary endpoint was myocardial infarction. Adjusted hazard ratios were calculated using diet-treated patients without coronary artery disease as reference.

RESULTS

In patients without coronary artery disease, risk of myocardial infarction was similar in patients treated with non-insulin medication (adjusted hazard ratio 0.70, 95% confidence interval 0.27-1.81) and insulin (adjusted hazard ratio 0.76, 95% confidence interval 0.27-2.08) as compared to diet only. In patients with coronary artery disease, the risk of myocardial infarction was higher than in the reference group and an incremental risk was observed being lowest in patients treated with diet (adjusted hazard ratio 3.79, 95% confidence interval 1.61-8.88), followed by non-insulin medication (adjusted hazard ratio 5.42, 95% confidence interval 2.40-12.22), and highest in insulin-treated patients (adjusted hazard ratio 7.91, 95% confidence interval 3.51-17.82).

CONCLUSION

The presence of obstructive coronary artery disease defines the risk of myocardial infarction in diabetes patients. Glucose-lowering therapy, in particular insulin, was associated with risk of myocardial infarction only in the presence of coronary artery disease.

Myocardial Ischemia and Diabetes Mellitus: Role of Oxidative Stress in the Connection between Cardiac Metabolism and Coronary Blood Flow

Ischemic heart disease (IHD) has several risk factors, among which diabetes mellitus represents one of the most important. In diabetic patients, the pathophysiology of myocardial ischemia remains unclear yet: some have atherosclerotic plaque which obstructs coronary blood flow, others show myocardial ischemia due to coronary microvascular dysfunction in the absence of plaques in epicardial vessels. In the cross-talk between myocardial metabolism and coronary blood flow (CBF), ion channels have a main role, and, in diabetic patients, they are involved in the pathophysiology of IHD. The exposition to the different cardiovascular risk factors and the ischemic condition determine an imbalance of the redox state, defined as oxidative stress, which shows itself with oxidant accumulation and antioxidant deficiency. In particular, several products of myocardial metabolism, belonging to oxidative stress, may influence ion channel function, altering their capacity to modulate CBF, in response to myocardial metabolism, and predisposing to myocardial ischemia. For this reason, considering the role of oxidative and ion channels in the pathophysiology of myocardial ischemia, it is allowed to consider new therapeutic perspectives in the treatment of IHD.

Coronary computed tomography angiography as a tool for long-term cardiovascular risk stratification in diabetic patients

Objectives of the study were to examine the long-term prognostic power of coronary computed tomography angiography (CCTA) to predict death or myocardial infarction in patients with diabetes mellitus (DM). The prognostic value of CCTA in diabetic patients has been confirmed for short- and intermediate follow-up durations. The slowly progressing nature of coronary artery disease (CAD), however, underlines the necessity to validate CCTA for longer observation periods in this high-risk population. A total of 132 patients with DM and 1781 without DM were examined by CCTA and followed for a median duration of 9.7 (IQR 6.9, 11.2) and 9.9 (IQR 6.9, 11.1) years, respectively. Cox proportional hazards analysis was used for the composite endpoint of death and myocardial infarction. Warranty period was defined as the number of years that an individual stays in a low-risk group with a cumulative probability for the endpoint below 1% and calculated for patients with/without DM and rising degrees of CAD. The study endpoint was reached in 12 (9.1%) patients with and 87 (4.9%) patients without DM (p = 0.024). Quantification of coronary stenosis by CADRADS or CAD severity (normal/non-obstructive/obstructive) was incremental for endpoint prediction with a multivariate (+Morise) χ² of 3.90 and 3.85, respectively. The lowest annual event rate of 0.19% was noted in non-diabetic patients with no CAD, translating to a warranty period of 5.26 years. The highest annual event rate of 1.73% was found in diabetic patients with obstructive CAD, corresponding to a warranty period of 0.58 years. Compared to patients with no DM and no CAD, the risk of death or myocardial infarction in diabetic patients increased with rising levels of coronary obstruction at multivariate hazard ratios (HR) of 3.28 [95% CI 2.32, 4.64 (p < 0.001)], 3.02 [95% CI 2.19, 4.17 (p < 0.001)] and 9.40 [95% CI 4.90, 18.03 (p < 0.001)] for normal coronary arteries, non-obstructive CAD and obstructive CAD. This study validates the long-term prognostic utility of CCTA-assessed CAD for predicting death or myocardial infarction in a population of patients with DM. The rates of death or myocardial infarction rise with CAD severity in diabetic and non-diabetic patients, identifying the highest risk group of patients with DM and obstructive CAD.

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.

Diabetes Mellitus and Ischemic Heart Disease: The Role of Ion Channels

Diabetes mellitus is one the strongest risk factors for cardiovascular disease and, in particular, for ischemic heart disease (IHD). The pathophysiology of myocardial ischemia in diabetic patients is complex and not fully understood: some diabetic patients have mainly coronary stenosis obstructing blood flow to the myocardium; others present with coronary microvascular disease with an absence of plaques in the epicardial vessels. Ion channels acting in the cross-talk between the myocardial energy state and coronary blood flow may play a role in the pathophysiology of IHD in diabetic patients. In particular, some genetic variants for ATP-dependent potassium channels seem to be involved in the determinism of IHD.

Myocardial perfusion at rest in uncomplicated type 2 diabetes patients without coronary artery disease evaluated by 320-multidetector computed tomography: A pilot study

Using computed tomography myocardial perfusion imaging (CTP) to investigate resting myocardial perfusion alterations in uncomplicated type 2 diabetes mellitus (T2DM) patients without obstructive coronary artery disease (CAD).A total of 34 participants with 544 myocardial segments were included prospectively: 17 uncomplicated T2DM patients with no significant coronary artery stenosis on coronary computed tomography angiography and 17 healthy controls. Myocardial perfusion was evaluated by transmural perfusion ratio (TPR). Parameters of cardiac structure and function were measured for cardiac comprehensive assessment. Analyses included descriptive statistics and group comparisons.TPR of segments 5, 7, 9, 10 to 14 were significantly reduced in T2DM group compared with controls (P < .05). When 16 myocardial segments were localized into different areas according to the wall orientations, axial levels of left ventricle and coronary artery territories, respectively, TPR of each area in T2DM group were significantly lower than those in the control group (P < .05). No significant differences were found in cardiac anatomy and function analyses between 2 groups.In uncomplicated T2DM patients without obstructive CAD, myocardial perfusion impairments were present and may develop prior to cardiac morphological and functional abnormalities, which can be early detected by CTP.

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.

Prediabetes is not a risk factor for subclinical coronary atherosclerosis

BACKGROUND

There are limited data regarding the influence of glycemic status on the risk of subclinical coronary atherosclerosis on coronary computed tomographic angiography (CCTA) in asymptomatic individuals.

METHODS

We analyzed 6434 asymptomatic individuals who underwent CCTA. The degree and extent of subclinical coronary atherosclerosis were assessed by CCTA, and ≥50% diameter stenosis was defined as significant. Of study participants, 2197 (34.1%), 3122 (48.5%), and 1115 (17.3%) were categorized as normal, prediabetic and diabetic individuals, respectively.

RESULTS

Compared with normal individuals, there were no statistically differences in the adjusted odds ratios of prediabetic individuals for significant coronary artery stenosis (0.98, 95% confidence interval [CI] 0.80-1.22, p=0.888), any plaque (0.96, 95% CI 0.86-1.07, p=0.483), calcified plaque (0.90, 95% CI 0.79-1.01, p=0.080), non-calcified plaque (1.02, 95% CI 0.88-1.17, p=0.803), and mixed plaque (1.00, 95% CI 0.82-1.22, p=0.983). However, adjusted odds ratios for significant coronary artery stenosis (1.71, 95% CI 1.34-2.19, p<0.001), any plaque (1.45, 95% CI 1.26-1.68, p<0.001), calcified plaque (1.35, 95% CI 1.15-1.57, p<0.001), non-calcified plaque (1.33, 95% CI 1.11-1.59, p=0.002), and mixed plaque (1.64, 95% CI 1.30-2.07, p<0.001) of diabetic individuals were significantly higher than those of the normal individuals.

CONCLUSION

In asymptomatic individuals, diabetic individuals had a higher risk for subclinical coronary atherosclerosis, but prediabetic individuals were not associated with an increased risk of subclinical coronary atherosclerosis.

In Vivo and In Vitro Analysis in Coronary Artery Disease Related to Type 2 Diabetes

AIM

The leading cause of morbidity and mortality in patients with type 2 diabetes mellitus (DM) is coronary artery disease (CAD), a condition often asymptomatic but severe in these patients. Although glucose metabolism impairment and oxidative stress are known actors in the endothelial dysfunction/remodeling that occurs in diabetic patients, the relationship between cardiovascular disorders and DM is not fully understood. We have performed both an in vivo imaging and in vitro molecular analysis to investigate diabetic-specific CAD alterations.

METHODS

Computed tomography coronary angiography (CTCA) was performed in a group of 20 diabetic patients with CAD (DM⁺CAD⁺), 20 non-diabetic with CAD (DM^-CAD⁺), 10 diabetic non-CAD patients (DM⁺CAD^-), and 20 non-diabetic healthy subjects (HS). Imaging quantitative parameters such as calcium score (Cascore), calcified plaque volume (CPV), non-calcified plaque volume (NCPV), total plaque volume (TPV), remodeling index (RI), and plaque burden were extracted for each CAD subject. Moreover, the expression levels of superoxide dismutase 2 (SOD2) and liver X receptor alpha (LXRα) genes were analyzed in the peripheral blood mononuclear cells, whereas hyaluronan (HA) concentrations were evaluated in the plasma of each subject.

RESULTS

Imaging parameters, such as Cascore, CPV, RI, and plaque burden, were significantly higher in DM⁺CAD⁺ group, compared to DM^-CAD⁺ (P = 0.019; P = 0.014; P < 0.001, P < 0.001, respectively). SOD2 mRNA was downregulated, while LXRα gene expression was upregulated in DM⁺CAD^-, DM⁺CAD⁺, and DM^-CAD⁺ groups compared to HS (P = 0.001, P = 0.03, and P = 0.001 for SOD2 and P = 0.006, P = 0.008, and P < 0.001 for LXRα, respectively). Plasmatic levels of HA were higher in DM^-CAD⁺, DM⁺CAD^-, and DM⁺CAD⁺ groups, compared to HS (P = 0.001 for the three groups). When compared to DM^-CAD⁺, HA concentration was higher in DM⁺CAD^- (P = 0.008) and DM⁺CAD⁺ (P < 0.001) with a significant difference between the two diabetic groups (P = 0.003). Moreover, HA showed a significant association with diabetes (P = 0.01) in the study population, and the correlation between HA levels and glycemia was statistically significant (ρ = 0.73, P < 0.001).

CONCLUSION

In our population, imaging parameters highlight a greater severity of CAD in diabetic patients. Among molecular parameters, HA is modulated by diabetic CAD-related alterations while SOD2 and LXRα are found to be more associated with CAD but do not discriminate between diabetic and non-diabetic subgroups.

Prognostic Value of Coronary Computed Tomography Angiography in Patients With Diabetes: A Meta-analysis

OBJECTIVE

The usefulness of coronary computed tomography angiography (CTA) for the evaluation of coronary artery disease (CAD) in patients with diabetes is ambiguous. We therefore performed a meta-analysis of studies reporting event rates and hazard ratios (HR) to determine the prognostic value of CTA in this patient population.

RESEARCH DESIGN AND METHODS

We searched PubMed and Embase up to November 2015. Study subjects' characteristics, events (all-cause mortality or cardiac death, nonfatal myocardial infarction, unstable angina pectoris, stroke, revascularization), and events excluding revascularization were collected. We calculated the prevalence of obstructive and nonobstructive CAD on CTA, annualized event rates, and pooled unadjusted and adjusted HR using a generic inverse random model.

RESULTS

Eight studies were eligible for inclusion into this meta-analysis, with 6,225 participants (56% male; weighted age, 61 years) with a follow-up period ranging from 20 to 66 months. The prevalence of obstructive CAD, nonobstructive CAD, and no CAD was 38%, 36%, and 25%, respectively. The annualized event rate was 17.1% for obstructive CAD, 4.5% for nonobstructive CAD, and 0.1% for no CAD. Obstructive and nonobstructive CAD were associated with an increased HR of 5.4 and 4.2, respectively. A higher HR for obstructive CAD was observed in studies including revascularization compared with those that did not (7.3 vs. 3.7, P = 0.124).

CONCLUSIONS

CTA in patients with diabetes allows for safely ruling out future events, and the detection of CAD could allow for the identification of high-risk patients in whom aggressive risk factor modification, medical surveillance, or elective revascularization could potentially improve survival.

Coronary Computed Tomography (CT) Angiography as a Predictor of Cardiac and Noncardiac Vascular Events in Asymptomatic Type 2 Diabetics: A 7-Year Population-Based Cohort Study

Background

Type 2 diabetics are at increased risk for vascular events, but the value of further risk stratification for coronary heart disease (CHD) in asymptomatic subjects is unclear. We examined the added value of coronary computed tomography angiography over clinical risk scores (United Kingdom Prospective Diabetes Study), and coronary artery calcium in a population‐based cohort of asymptomatic type 2 diabetics.

Methods and Results

Subjects (n=630) underwent baseline clinical assessment and computed tomography angiography (64‐slice scanner). Plaque site, volume, calcific content, and arterial remodeling were recorded using dedicated software. Coronary, macrovascular, and microvascular‐related events were assessed over 6.6±0.6 (mean±SD) (range 5.4–7.5) years and all CHD events were adjudicated. Discrimination of CHD events (cardiovascular death, myocardial infarction, unstable angina, or new‐onset angina requiring intervention) (n=41) was improved by addition of total plaque burden to the clinical risk and coronary artery calcium scores combined (C=0.789 versus 0.763, P=0.034) and further improved by addition of an angiographic score (C=0.824, P=0.021). Independent predictors of a CHD event were United Kingdom Prospective Diabetes Study risk score (hazard ratio 1.3 per 10% 10‐year risk, P=0.003) and the angiographic score (hazard ratio 3.2 per quartile, P<0.0001). Classification was improved over that by United Kingdom Prospective Diabetes Study and coronary artery calcium scores alone (overall net reclassification improvement 0.24). In subjects with coronary plaque (N=500), mild plaque calcification independently predicted a CHD event (hazard ratio 3.0, P=0.02). Computed tomography angiography predicted combined macrovascular but not microvascular‐related events.

Conclusions

Computed tomography angiography provides additional prognostic information in asymptomatic type 2 diabetics not obtainable from clinical risk assessment and coronary artery calcium alone.

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.

Low-dose CT coronary angiography for assessment of coronary artery disease in patients with type 2 diabetes--a cross-sectional study

Background

Silent coronary artery disease (CAD) is prevalent in type 2 diabetes mellitus (T2DM). Although coronary computed tomography angiography (CCTA) over recent years has emerged a useful tool for assessing and diagnosing CAD it’s role and applicability for patients with T2DM is still unclarified, in particular in asymptomatic patients. We aimed to assess the role of CCTA in detecting and characterizing CAD in patients with T2DM without cardiac symptoms when compared to gold standard invasive coronary angiography (ICA).

Methods

This was a cross-sectional analysis of patients with T2DM without symptomatic CAD enrolled in the Asker and Baerum Cardiovascular Diabetes Study who, following clinical examination and laboratory assessment, underwent subsequently CCTA and ICA.

Results

In total 48 Caucasian patients with T2DM (36 men, age 64.0 ± 7.3 years, diabetes duration 14.6 ± 6.4 years, HbA1c 7.4 ± 1.1 %, BMI 29.6 ± 4.3 kg/m²) consented to, and underwent, both procedures (CCTA and ICA). The population was at intermediate cardiovascular risk (mean coronary artery calcium score 269, 75 % treated with antihypertensive therapy). ICA identified a prevalence of silent CAD at 17 % whereas CCTA 35 %. CCTA had a high sensitivity (100 %) and a high negative predictive value (100 %) for detection of patients with CAD when compared to ICA, but the positive predictive value was low (47 %).

Conclusions

Low-dose CCTA is a reliable method for detection and exclusion of significant CAD in T2DM and thus may be a useful tool for the clinicians. However, a low positive predictive value may limit its usefulness as a screening tool for all CAD asymptomatic patients with T2DM. Further studies should assess the applicability for risk assessment beyond the evaluation of the vascular bed.

Plaque disruption by coronary computed tomographic angiography in stable patients vs. acute coronary syndrome: a feasibility study

AIMS

This study was designed to determine whether coronary CT angiography (CTA) can detect features of plaque disruption in clinically stable patients and to compare lesion prevalence and features between stable patients and those with acute coronary syndrome (ACS).

METHODS

We retrospectively identified patients undergoing CTA, followed by invasive coronary angiography (ICA) within 60 days. Quantitative 3-vessel CTA lesion analysis was performed on all plaques ≥25% stenosis to assess total plaque volume, low attenuation plaque (LAP, <50 HU) volume, and remodelling index. Plaques were qualitatively assessed for CTA features of disruption, including ulceration and intra-plaque dye penetration (IDP). ICA was employed as a reference standard for disruption. A total of 145 (94 ACS and 51 stable) patients were identified. By CTA, plaque disruption was evident in 77.7% of ACS cases. Although more common among those with ACS, CTA also detected plaque disruption in 37.3% of clinically stable patients (P < 0.0001).

CONCLUSIONS

Clinically stable patients commonly manifest plaques with features of disruption as determined by CTA. Though the prevalence of plaque disruption is less than patients with ACS, these findings support the concept that some clinically stable patients may harbour 'silent' disrupted plaques. These findings may have implications for detection of 'at risk' plaques and patients.

Comparison of Coronary Computed Tomographic Angiographic Findings in Asymptomatic Subjects With Versus Without Diabetes Mellitus

There are limited data on the impact of diabetes mellitus (DM) on the risk of subclinical atherosclerosis. Therefore, we sought to investigate the impact of DM on the risk of subclinical atherosclerosis in asymptomatic subjects. We analyzed 2,034 propensity score-matched asymptomatic subjects who underwent coronary computed tomographic angiography (mean age 55.9 ± 8.2 years; men 1,725 [84.8%]). Coronary artery calcium score, degree and extent of coronary artery disease (CAD), and clinical outcomes were assessed. High-risk CAD was defined as at least 2-vessel coronary disease with proximal left anterior descending artery involvement, 3-vessel disease, or left main disease. Compared with subjects without DM, those matched with DM had higher coronary artery calcium score (89.9 ± 240.4 vs 62.8 ± 179.5, p = 0.004) and more significant CAD (≥50% diameter stenosis, 15.2% vs 10.2%, p = 0.001), largely in the form of 1-vessel disease (10.8% vs 7.3%, p = 0.007). However, there were no significant differences between matched pairs in significant CAD in the left main or proximal left anterior descending artery (5.3% vs 3.8%, p = 0.138), multivessel disease (4.4% vs 2.9%, p = 0.101), and high-risk CAD (4.3% vs 2.7%, p = 0.058). During the follow-up period (median 21.8, interquartile range 15.2 to 33.4 months), there was no significant difference in the composite of all-cause death, myocardial infarction, acute coronary syndrome, and coronary revascularization between 2 groups (hazard ratio 1.438, 95% confidence interval 0.844 to 2.449, p = 0.181). In asymptomatic subjects, those matched with DM have more subclinical atherosclerosis, mainly confined to non-high-risk CAD, than those matched without DM, and there are no differences in high-risk CAD and clinical outcomes.

Assessment of cardiovascular risk in diabetes: Risk scores and provocative testing

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality among patients with diabetes mellitus, who have a risk of cardiovascular mortality two to four times that of people without diabetes. An individualised approach to cardiovascular risk estimation and management is needed. Over the past decades, many risk scores have been developed to predict CVD. However, few have been externally validated in a diabetic population and limited studies have examined the impact of applying a prediction model in clinical practice. Currently, guidelines are focused on testing for CVD in symptomatic patients. Atypical symptoms or silent ischemia are more common in the diabetic population, and with additional markers of vascular disease such as erectile dysfunction and autonomic neuropathy, these guidelines can be difficult to interpret. We propose an algorithm incorporating cardiovascular risk scores in combination with typical and atypical signs and symptoms to alert clinicians to consider further investigation with provocative testing. The modalities for investigation of CVD are discussed.

Risk score model for the assessment of coronary artery disease in asymptomatic patients with type 2 diabetes

No model has been developed to predict significant coronary artery disease (CAD) on coronary computed tomographic angiography (CCTA) in asymptomatic type 2 diabetes. Therefore, we sought to develop a model for the prediction of significant CAD on CCTA in these patients. We analyzed 607 asymptomatic patients with type 2 diabetes who underwent CCTA. The cardiac event was defined as a composite of cardiac death, nonfatal myocardial infarction, acute coronary syndrome, and coronary revascularization. Significant CAD (diameter stenosis ≥50%) in at least one coronary artery on CCTA was observed in 188 (31.0%). During the follow-up period (median 4.3 [interquartile range, 3.7-4.8] years), 71 patients had 83 cardiac events. Clinical risk factors for significant CAD were age, male gender, duration of diabetes, hypertension, current smoking, family history of premature CAD, previous history of stroke, ratio of total cholesterol to high-density lipoprotein cholesterol, and neuropathy. Using these variables, we formulated a risk score model, and the scores ranged from 0 to 17 (area under the curve = 0.727, 95% confidence interval = 0.714-0.739, P < 0.001). Patients were categorized into low (≤3), intermediate (4-6), or high (≥7) risk group. There were significant differences between the risk groups in the probability of significant CAD (12.6% vs 29.4% vs 57.7%, P for all < 0.001) and 5-year cardiac event-free survival rate (96.6% ± 1.5% vs 88.9% ± 1.8% vs 73.8% ± 4.1%, log-rank P for trend < 0.001). This model predicts significant CAD on CCTA and has the potential to identify asymptomatic type 2 diabetes with high risk.

Value of multi-detector computed tomography angiography in predicting acute cardiac events in patients with type 2 diabetes

The aim of the present study was to investigate the predictive value of multi-detector computed tomography angiography (MDCTA) on acute coronary artery events in patients with type 2 diabetes mellitus (T2DM). MDCTA was performed in 150 patients with T2DM (males, 74; mean age, 66±6.7 years for all patients) that had experienced atypical chest pains. After a follow-up period of at least 2 years, 55 patients were excluded from the study as they did not exhibit any coronary events. The remaining 95 patients were divided into the study group (n=28), that had experienced an acute coronary event such as acute coronary syndrome, or the control group (n=67) that had stable angina. There were no statistically significant differences in the degree of coronary artery lumen stenosis between the study and control groups (P=0.380). The proportion of calcified plaques in the study group was significantly lower compared with the control group (13.6 vs. 53.2%; P<0.001), while the proportion of soft plaques in the study group was significantly higher compared with the control group (37 vs. 9.3%; P<0.001). Type III plaques showed a sensitivity of 76.2% and a negative predictive value of 64.5% for acute coronary events. By contrast, type IV plaques had a sensitivity of 52.6% and a positive predictive value of 63% for chronic coronary events. Therefore, the results of the present study indicate that MDCTA may be used as a noninvasive modality for evaluating and predicting vulnerable coronary atherosclerosis plaques in patients with T2DM.

Predictive value of high-sensitivity troponin-I for future adverse cardiovascular outcome in stable patients with type 2 diabetes mellitus

Introduction

High-sensitivity cardiac troponin I(hs-TnI) and T levels(hs-TnT) are sensitive biomarkers of cardiomyocyte turnover or necrosis. Prior studies of the predictive role of hs-TnT in type 2 diabetes mellitus(T2DM) patients have yielded conflicting results. This study aimed to determine whether hs-TnI, which is detectable in a higher proportion of normal subjects than hsTnT, is associated with a major adverse cardiovascular event(MACE) in T2DM patients.

Methods and results

We compared hs-TnI level in stored serum samples from 276 consecutive patients (mean age 65 ± 10 years; 57% male) with T2DM with that of 115 age-and sex-matched controls. All T2DM patients were prospectively followed up for at least 4 years for incidence of MACE including heart failure(HF), myocardial infarction(MI) and cardiovascular mortality. At baseline, 274(99%) patients with T2DM had detectable hs-TnI, and 57(21%) had elevated hs-TnI (male: 8.5 ng/L, female: 7.6 ng/L, above the 99^th percentile in healthy controls). A total of 43 MACE occurred: HF(n = 18), MI(n = 11) and cardiovascular mortality(n = 14). Kaplan-Meier analysis showed that an elevated hs-TnI was associated with MACE, HF, MI and cardiovascular mortality. Although multivariate analysis revealed that an elevated hs-TnI independently predicted MACE, it had limited sensitivity(62.7%) and positive predictive value(38.5%). Contrary to this, a normal hs-TnI level had an excellent negative predictive value(92.2%) for future MACE in patients with T2DM.

Conclusion

The present study demonstrates that elevated hs-TnI in patients with T2DM is associated with increased MACE, HF, MI and cardiovascular mortality. Importantly, a normal hs-TnI level has an excellent negative predictive value for future adverse cardiovascular events during long-term follow-up.

Prognostic utility of coronary computed tomographic angiography: a 5-year follow-up in type 2 diabetes patients with suspected coronary artery disease

OBJECTIVES

To analyze the predictive value of coronary computed tomography angiography on acute coronary artery events in patients with type 2 diabetes.

METHODS

Coronary computed tomography angiography was performed in 250 type 2 diabetic patients. After a follow-up for 5 years, 145 patients were excluded as they did not have any coronary events. The remaining 95 patients were divided into study group and control group. According to their density and shape, the coronary artery plaques were classified into 3 types and 4 types, respectively.

RESULTS

There is no statistically significant difference in the degree of stenosis between two groups. The proportion of calcified plaques in the study group was lower than in the control group. The proportion of mixed-calcified plaques in the study group was higher than in the other. Type III plaques have a 76.2% sensitivity and negative predictive value was 64.5% for acute coronary events; type IV plaques have a sensitivity of 52.6% and positive predictive value of 63% for chronic coronary events.

CONCLUSIONS

CCTA may be used as a non-invasive modality for evaluating and predicting vulnerable coronary atherosclerosis plaques in patients with type 2 diabetes.

Coronary computed tomographic angiographic findings in asymptomatic patients with type 2 diabetes mellitus

There are limited data regarding the role of coronary computed tomographic angiography (CCTA) in asymptomatic patients with type 2 diabetes mellitus. We analyzed 557 asymptomatic type 2 diabetic patients who underwent CCTA. Cardiac event was defined as a composite of cardiac death, nonfatal myocardial infarction, acute coronary syndrome requiring hospitalization, or late revascularization. Atherosclerotic plaques were observed in 395 patients (70.9%), and 170 patients (30.5%) showed significant coronary artery disease (CAD) on CCTA. Ninety-two patients (16.5%) were associated with a significant stenosis in the left main or proximal left anterior descending artery. During the follow-up period (33.7 ± 7.8 months), although an excellent prognosis was observed in patients without significant CAD on CCTA, those with significant CAD showed more cardiac events (7.1% vs 0.5%) and lower 3-year event-free survival rates (99.2 ± 0.6% vs 90.9 ± 2.6%, p <0.001). Furthermore, in group with significant CAD, patients with significant CAD in the left main or proximal left anterior descending artery had more cardiac events (10.9% vs 2.6%) and lower 3-year event-free survival rates (97.4 ± 1.8% vs 86.1 ± 4.2%, p = 0.049). On multivariate analysis, family history of premature CAD, previous history of stroke, higher UK Prospective Diabetes Study 10-year risk scores, neuropathy, and retinopathy were independent clinical predictors of having significant CAD and left main or proximal left anterior descending artery significant CAD on CCTA. In conclusion, about 1/3 of asymptomatic type 2 diabetic patients had significant CAD on CCTA with a subsequent high risk for cardiac events. These findings suggest that CCTA may have a potential role in identifying patients with high cardiovascular risks in asymptomatic type 2 diabetes.

Unprotected left main coronary artery disease after revascularization : effect of diabetes on patient outcomes

OBJECTIVE

It is unknown whether the effect of diabetes on patients with unprotected left main coronary artery (LMCA) disease differs according to the different revascularization strategies. This study was conducted to evaluate the impact of diabetes on patients with unprotected LMCA disease treated with either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG).

PATIENTS AND METHODS

We prospectively enrolled 823 consecutive patients with unprotected LMCA disease who had drug-eluting stent (DES; n = 331) implantation or underwent CABG (n = 492) in the study. We compared the effects of diabetes on clinical outcomes according to different revascularization strategies.

RESULTS

Among 823 eligible patients enrolled, 226 had diabetes. In the DES population, no significant differences were observed in occurrences of death, cardiac death, repeat revascularization, stroke, and major adverse cardiac and cerebrovascular events. However, the risks of the composite of death/myocardial infarction (MI)/stroke (21.5 % DM vs. 7.2 % non-DM; p = 0.001) and MI (15.4 % DM vs. 1.6 % non-DM; p = 0.000) were significantly higher in the diabetic patients than those without diabetes. In the CABG population, similar rates of all clinical endpoints were observed between the diabetic and nondiabetic group.

CONCLUSION

Diabetes was associated with worse outcome in patients undergoing DES implantation for the treatment of unprotected LMCA disease. However, its negative prognostic impact was not found among patients undergoing CABG.

Incremental prognostic value of coronary computed tomographic angiography over coronary artery calcium score for risk prediction of major adverse cardiac events in asymptomatic diabetic individuals

BACKGROUND

Coronary artery disease (CAD) diagnosis by coronary computed tomographic angiography (CCTA) is useful for identification of symptomatic diabetic individuals at heightened risk for death. Whether CCTA-detected CAD enables improved risk assessment of asymptomatic diabetic individuals beyond clinical risk factors and coronary artery calcium scoring (CACS) remains unexplored.

METHODS

From a prospective 12-center international registry of 27,125 individuals undergoing CCTA, we identified 400 asymptomatic diabetic individuals without known CAD. Coronary stenosis by CCTA was graded as 0%, 1-49%, 50-69%, and ≥70%. CAD was judged on a per-patient, per-vessel and per-segment basis as maximal stenosis severity, number of vessels with ≥50% stenosis, and coronary segments weighted for stenosis severity (segment stenosis score), respectively. We assessed major adverse cardiovascular events (MACE) - inclusive of mortality, nonfatal myocardial infarction (MI), and late target vessel revascularization ≥90 days (REV) - and evaluated the incremental utility of CCTA for risk prediction, discrimination and reclassification.

RESULTS

Mean age was 60.4 ± 9.9 years; 65.0% were male. At a mean follow-up 2.4 ± 1.1 years, 33 MACE occurred (13 deaths, 8 MI, 12 REV) [8.25%; annualized rate 3.4%]. By univariate analysis, per-patient maximal stenosis [hazards ratio (HR) 2.24 per stenosis grade, 95% confidence interval (CI) 1.61-3.10, p < 0.001], increasing numbers of obstructive vessels (HR 2.30 per vessel, 95% CI 1.75-3.03, p < 0.001) and segment stenosis score (HR 1.14 per segment, 95% CI 1.09-1.19, p < 0.001) were associated with increased MACE. After adjustment for CAD risk factors and CACS, maximal stenosis (HR 1.80 per grade, 95% CI 1.18-2.75, p = 0.006), number of obstructive vessels (HR 1.85 per vessel, 95% CI 1.29-2.65, p < 0.001) and segment stenosis score (HR 1.11 per segment, 95% CI 1.05-1.18, p < 0.001) were associated with increased risk of MACE. Beyond age, gender and CACS (C-index 0.64), CCTA improved discrimination by maximal stenosis, number of obstructive vessels and segment stenosis score (C-index 0.77, 0.77 and 0.78, respectively). Similarly, CCTA findings improved risk reclassification by per-patient maximal stenosis [integrated discrimination improvement (IDI) index 0.03, p = 0.03] and number of obstructive vessels (IDI index 0.06, p = 0.002), and by trend for segment stenosis score (IDI 0.03, p = 0.06).

CONCLUSION

For asymptomatic diabetic individuals, CCTA measures of CAD severity confer incremental risk prediction, discrimination and reclassification on a per-patient, per-vessel and per-segment basis.

Association of cardiac events with coronary artery disease detected by 64-slice or greater coronary CT angiography: a systematic review and meta-analysis

BACKGROUND

The value of ≥64-slice coronary CT angiography (CCTA) to determine odds of cardiac death or non-fatal myocardial infarction (MI) needs further clarification.

METHODS

We performed a systematic review and meta-analysis using publications reporting events/severity of coronary artery disease (CAD) in patients with suspected CAD undergoing CCTA. Patients were divided into: no CAD, non-obstructive CAD (maximal stenosis <50%), and obstructive CAD (≥50% stenosis). Odds ratios with 95% confidence intervals were calculated using a fixed or random effects model. Heterogeneity was assessed using the I(2) index.

RESULTS

We included thirty-two studies comprising 41,960 patients with 363 all-cause deaths (15.0%), 114 cardiac deaths (4.7%), 342 MI (14.2%), 69 unstable angina (2.8%), and 1527 late revascularizations (63.2%) over 1.96 (SD 0.77) years of follow-up. Cardiac death or MI occurred in 0.04% without, 1.29% with non-obstructive, and 6.53% with obstructive CAD. OR for cardiac death or MI was: 14.92 (95% CI, 6.78 to 32.85) for obstructive CAD, 6.41 (95% CI, 2.44 to 16.84) for non-obstructive CAD versus no CAD, and 3.19 (95% CI, 2.29 to 4.45) for non-obstructive versus obstructive CAD and 6.56 (95% CI, 3.07 to 14.02) for no versus any CAD. Similar trends were noted for all-cause mortality and composite major adverse cardiovascular events.

CONCLUSIONS

Increasing CAD severity detected by CCTA is associated with cardiac death or MI, all-cause mortality, and composite major adverse cardiovascular events. Absence of CAD is associated with very low odds of major adverse events, but non-obstructive disease significantly increases odds of cardiac adverse events in this follow-up period.

Prognostic value of multidetector computed tomography coronary angiography in diabetes: excellent long-term prognosis in patients with normal coronary arteries

OBJECTIVE

To assess the prognostic role of multidetector computed tomography coronary angiography (MDCT-CA) in patients with diabetes with suspected coronary artery disease (CAD). Use of MDCT-CA is increasing in patients with suspected CAD. However, data supporting its prognostic value in patients with diabetes are limited.

RESEARCH DESIGN AND METHODS

Between January 2006 and September 2007, 429 consecutive diabetic patients were prospectively studied with MDCT-CA for detecting the presence and assessing the extent of CAD (disease extension and coronary plaque scores). Patients were classified according to the presence of normal coronary arteries and nonobstructive (<50%) and obstructive (≥50%) coronary lesions. The composite rates of hard cardiac events (cardiac death, nonfatal myocardial infarction, unstable angina) and all cardiac events (including revascularization) were the end points of the study.

RESULTS

Twenty-four patients were excluded because MDCT-CA data were not able to be interpreted. Of the remaining 405 patients, clinical follow-up (mean 62 ± 9 months) was obtained in 390 (98%). Multivariate analysis showed that predictors of hard and all events were obstructive CAD, three-vessel CAD, and left main coronary artery (LMCA) disease. Cumulative event-free survival was 100% for hard and all events in patients with normal coronary arteries, 78% for hard events and 56% for all events in patients with nonobstructive CAD, and 60% for hard events and 16% for all events in patients with obstructive CAD. Three-vessel CAD and LMCA disease were associated with a higher rate of hard cardiac events.

CONCLUSIONS

MDCT-CA provides long-term prognostic information for patients with diabetes with suspected CAD, showing excellent prognosis when there is no evidence of atherosclerosis and allowing risk stratification when CAD is present.

Rationale, design and methods of CTCA-PRORECAD (Computed Tomography Coronary Angiography Prognostic Registry for Coronary Artery Disease): a multicentre and multivendor registry

PURPOSE

This study was done to assess the prognostic value of computed tomography coronary angiography (CTCA) in a large multicentre population of patients with suspected coronary artery disease (CAD) and, in particular, its incremental value compared with traditional methods for risk stratification.

MATERIALS AND METHODS

This is a retrospective observational study that began in January 2003 conducted on patients with suspected CAD assessed with CTCA on the basis of symptoms (chest pain, dyspnoea) and/or abnormal or equivocal stress test and/or a high cardiovascular risk profile. The participating centres will provide data obtained with CTCA performed with 16-slice or higher equipment. Exclusion criteria are renal insufficiency, allergy to iodinated contrast material, pregnancy and previous myocardial infarction or revascularisation (percutaneous coronary intervention and/or coronary artery bypass graft). All patients are stratified by means of clinical assessment and/or data retrieved from a clinical database. Risk factors considered are hypertension, dyslipidaemia, diabetes mellitus, smoking, family history and obesity. Symptoms are classified as absent, typical chest pain, atypical chest pain and dyspnoea. Primary endpoints are death, major adverse cardiovascular events (cardiac death, unstable angina requiring hospitalisation, acute myocardial infarction) and shifting of cardiovascular risk category on the basis of coronary plaque burden. The secondary endpoint is coronary revascularisation. Telephone interviews and/or clinical databases are used for the follow-up. The study will be conducted on a population >1,000 patients.

CONCLUSIONS

The information collected from the Prognostic Registry for Coronary Artery Disease (PRORECAD) will provide insight into the prognostic value of CTCA in addition to demographic and clinical features. The results will allow for better use and interpretation of CTCA for prognostic purposes.

Differences in prevalence, extent, severity, and prognosis of coronary artery disease among patients with and without diabetes undergoing coronary computed tomography angiography: results from 10,110 individuals from the CONFIRM (COronary CT Angiography EvaluatioN For Clinical Outcomes): an InteRnational Multicenter Registry

OBJECTIVE

We examined the prevalence, extent, severity, and prognosis of coronary artery disease (CAD) in individuals with and without diabetes (DM) who are similar in CAD risk factors.

RESEARCH DESIGN AND METHODS

We identified 23,643 consecutive individuals without known CAD undergoing coronary computed tomography angiography. A total of 3,370 DM individuals were propensity matched in a 1-to-2 fashion to 6,740 unique non-DM individuals. CAD was defined as none, nonobstructive (1-49% stenosis), or obstructive (≥ 50% stenosis). All-cause mortality was assessed by risk-adjusted Cox proportional hazards models.

RESULTS

At a 2.2-year follow-up, 108 (3.2%) and 115 (1.7%) deaths occurred among DM and non-DM individuals, respectively. Compared with non-DM individuals, DM individuals possessed higher rates of obstructive CAD (37 vs. 27%) and lower rates of having normal arteries (28 vs. 36%) (P < 0.0001). CAD extent was higher for DM versus non-DM individuals for obstructive one-vessel disease (19 vs. 14%), two-vessel disease (9 vs. 7%), and three-vessel disease (9 vs. 5%) (P < 0.0001 for comparison), with higher per-segment stenosis in the proximal and mid-segments of every coronary artery (P < 0.001 for all). Compared with non-DM individuals with no CAD, risk of mortality for DM individuals was higher for those with no CAD (hazard ratio 3.63 [95% CI 1.67-7.91]; P = 0.001), nonobstructive CAD (5.25 [2.56-10.8]; P < 0.001), one-vessel disease (6.39 [2.98-13.7]; P < 0.0001), two-vessel disease (12.33 [5.622-27.1]; P < 0.0001), and three-vessel disease (13.25 [6.15-28.6]; P < 0.0001).

CONCLUSIONS

Compared with matched non-DM individuals, DM individuals possess higher prevalence, extent, and severity of CAD. At comparable levels of CAD, DM individuals experience higher risk of mortality compared with non-DM individuals.

Coronary artery calcium scoring, what is answered and what questions remain

Coronary artery calcification (CAC) is a widely used imaging modality for cardiovascular risk assessment in moderate risk patients. It has been shown to have a superior role predicting future cardiac events and survival rates when combined with other traditional risk factor scoring systems as Framingham risk score (FRS). Furthermore, it significantly reclassifies moderate risk patients into lower or higher risk categories. Higher risk groups like patients with diabetes, a higher prevalence of CAC has been shown to impart a high short term risk of CV events, while those with zero calcium score had excellent event-free survival, similar to non-diabetic patients. Having a zero calcium score is currently used in United Kingdom practice guidelines (NICE) as a gatekeeper for any further investigations in patients presenting to the emergency department (ED) with chest pain. Unanswered questions include the concept of CAC progression that need to be standardized with respect to technique, interpretation and subsequent management strategies. Studies also demonstrated that risk assessment using CAC was motivational to patients leading to better adherence to their preventive practices as well as medications. However, statin did not consistently prove beneficial in slowing the CAC progression rate, but did reduce CV events significantly in patients with increased CAC. Accordingly, more studies need to be conducted to further help understand the ideal way to utilize this imaging tool and decreasing downstream utilization.

Clinical indications for cardiac computed tomography. From the Working Group of the Cardiac Radiology Section of the Italian Society of Medical Radiology (SIRM)

Cardiac computed tomography (CCT) has grown as a useful means in different clinical contexts. Technological development has progressively extended the indications for CCT while reducing the required radiation dose. Even today there is little documentation from the main international scientific societies describing the proper use and clinical indications of CCT; in particular, there are no complete guidelines. This document reflects the position of the Working Group of the Cardiac Radiology Section of the Italian Society of Radiology concerning the indications for CCT.