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

Precision prognostics for cardiovascular disease in Type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Precision medicine has the potential to improve cardiovascular disease (CVD) risk prediction in individuals with Type 2 diabetes (T2D).

METHODS

We conducted a systematic review and meta-analysis of longitudinal studies to identify potentially novel prognostic factors that may improve CVD risk prediction in T2D. Out of 9380 studies identified, 416 studies met inclusion criteria. Outcomes were reported for 321 biomarker studies, 48 genetic marker studies, and 47 risk score/model studies.

RESULTS

Out of all evaluated biomarkers, only 13 showed improvement in prediction performance. Results of pooled meta-analyses, non-pooled analyses, and assessments of improvement in prediction performance and risk of bias, yielded the highest predictive utility for N-terminal pro b-type natriuretic peptide (NT-proBNP) (high-evidence), troponin-T (TnT) (moderate-evidence), triglyceride-glucose (TyG) index (moderate-evidence), Genetic Risk Score for Coronary Heart Disease (GRS-CHD) (moderate-evidence); moderate predictive utility for coronary computed tomography angiography (low-evidence), single-photon emission computed tomography (low-evidence), pulse wave velocity (moderate-evidence); and low predictive utility for C-reactive protein (moderate-evidence), coronary artery calcium score (low-evidence), galectin-3 (low-evidence), troponin-I (low-evidence), carotid plaque (low-evidence), and growth differentiation factor-15 (low-evidence). Risk scores showed modest discrimination, with lower performance in populations different from the original development cohort.

CONCLUSIONS

Despite high interest in this topic, very few studies conducted rigorous analyses to demonstrate incremental predictive utility beyond established CVD risk factors for T2D. The most promising markers identified were NT-proBNP, TnT, TyG and GRS-CHD, with the highest strength of evidence for NT-proBNP. Further research is needed to determine their clinical utility in risk stratification and management of CVD in T2D.

Ten-year prognostic value of coronary CT angiography in asymptomatic patients with type 2 diabetes

INTRODUCTION AND OBJECTIVES

The United Kingdom Prospective Diabetes Study (UKPDS) risk score has limited value for predicting coronary artery disease (CAD) events. We investigated the additive value of coronary computed tomography angiography (CCTA) on top of the UKPDS risk score in predicting 10-year adverse cardiac events in asymptomatic patients with type 2 diabetes.

METHODS

We evaluated 589 asymptomatic diabetic patients without a history of CAD who underwent CCTA. The primary outcome was a composite of cardiac death, nonfatal myocardial infarction, unstable angina requiring hospitalization, and revascularization. We estimated the discrimination and reclassification ability for the prediction models, which included combinations of the UKPDS category, severity of stenosis, and coronary artery calcium score by CCTA.

RESULTS

The incidence of the primary outcome was 12.4%. During 10 years of follow-up, patients without plaque by CCTA tended to have a low CAD event rate, while those with obstructive CAD tended to have a high event rate, irrespective of the baseline UKPDS risk category. The model that included only the UKPDS category had a Harrell's c-index of 0.658; adding the degree of stenosis to the model significantly increased the c-index by 0.066 (P=.004), while adding coronary artery calcium score increased the c-index by only 0.039 (P=.056). Overall, CCTA information in addition to the UKPDS risk category improved the reclassification rate for predicting the primary outcome.

CONCLUSIONS

In asymptomatic patients with type 2 diabetes, CCTA information for CAD provided significant incremental discriminatory power beyond the UKPDS risk score category for predicting 10-year adverse coronary events.

Precision Prognostics for Cardiovascular Disease in Type 2 Diabetes: A Systematic Review and Meta-analysis

Background Precision medicine has the potential to improve cardiovascular disease (CVD) risk prediction in individuals with type 2 diabetes (T2D). Methods We conducted a systematic review and meta-analysis of longitudinal studies to identify potentially novel prognostic factors that may improve CVD risk prediction in T2D. Out of 9380 studies identified, 416 studies met inclusion criteria. Outcomes were reported for 321 biomarker studies, 48 genetic marker studies, and 47 risk score/model studies. Results Out of all evaluated biomarkers, only 13 showed improvement in prediction performance. Results of pooled meta-analyses, non-pooled analyses, and assessments of improvement in prediction performance and risk of bias, yielded the highest predictive utility for N-terminal pro b-type natriuretic peptide (NT-proBNP) (high-evidence), troponin-T (TnT) (moderate-evidence), triglyceride-glucose (TyG) index (moderate-evidence), Genetic Risk Score for Coronary Heart Disease (GRS-CHD) (moderate-evidence); moderate predictive utility for coronary computed tomography angiography (low-evidence), single-photon emission computed tomography (low-evidence), pulse wave velocity (moderate-evidence); and low predictive utility for C-reactive protein (moderate-evidence), coronary artery calcium score (low-evidence), galectin-3 (low-evidence), troponin-I (low-evidence), carotid plaque (low-evidence), and growth differentiation factor-15 (low-evidence). Risk scores showed modest discrimination, with lower performance in populations different from the original development cohort. Conclusions Despite high interest in this topic, very few studies conducted rigorous analyses to demonstrate incremental predictive utility beyond established CVD risk factors for T2D. The most promising markers identified were NT-proBNP, TnT, TyG and GRS-CHD, with the highest strength of evidence for NT-proBNP. Further research is needed to determine their clinical utility in risk stratification and management of CVD in T2D.

Prognostic Value of Coronary Calcium Score in Asymptomatic Individuals: A Systematic Review

Despite updated guidelines and technological developments that allow for an accurate diagnosis, many asymptomatic individuals have a high risk of developing CAD or cardiac events. The CAC score can estimate a correct risk level for these subjects, which is clinically significant for adequate management of risk factors and obtaining personalized preventive therapy. This systematic review aims to assess the prognostic value of CAC score in asymptomatic individuals. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, a systematic literature search was performed to identify original articles since 2010 that evaluated the prognostic value of CAC score in asymptomatic individuals. The quality of the included studies was assessed by the QUIPS tool. A total of 45 articles were selected. Many of these (25 studies) evaluated the prognostic value of CAC score in asymptomatic subjects. In comparison, others (20 studies) evaluated the association of CAC score with other clinical parameters and imaging modalities or the comparison with computed tomography coronary angiography (CTCA). Our findings showed that the CAC score provides valuable prognostic information for predicting CAD risk in asymptomatic individuals.

The role of cardiac computed tomography in predicting adverse coronary events

Cardiac computed tomography (CCT) is now considered a first-line diagnostic test for suspected coronary artery disease (CAD) providing a non-invasive, qualitative, and quantitative assessment of the coronary arteries and pericoronary regions. CCT assesses vascular calcification and coronary lumen narrowing, measures total plaque burden, identifies plaque composition and high-risk plaque features and can even assist with hemodynamic evaluation of coronary lesions. Recent research focuses on computing coronary endothelial shear stress, a potent modulator in the development and progression of atherosclerosis, as well as differentiating an inflammatory from a non-inflammatory pericoronary artery environment using the simple measurement of pericoronary fat attenuation index. In the present review, we discuss the role of the above in the diagnosis of coronary atherosclerosis and the prediction of adverse cardiovascular events. Additionally, we review the current limitations of cardiac computed tomography as an imaging modality and highlight how rapid technological advancements can boost its capacity in predicting cardiovascular risk and guiding clinical decision-making.

Heterogeneity in coronary heart disease risk

There is large inter-individual heterogeneity in risk of coronary heart disease (CHD). Risk factors traditionally used in primary risk assessment only partially explain this heterogeneity. Residual, unobserved heterogeneity leads to age-related attenuation of hazard rates and underestimation of hazard ratios. Its magnitude is unknown. Therefore, we aimed to estimate a lower and an approximate upper bound. Heterogeneity was parametrized by a log-normal distribution with shape parameter σ. Analysis was based on published data. From concordance indices of studies including traditional risk factors and additional diagnostic imaging data, we calculated the part of heterogeneity explained by imaging data. For traditional risk assessment, this part typically remains unexplained, thus constituting a lower bound on unobserved heterogeneity. Next, the potential impact of heterogeneity on CHD hazard rates in several large countries was investigated. CHD rates increase with age but the increase attenuates with age. Presuming this attenuation to be largely caused by heterogeneity, an approximate upper bound on σ was derived. Taking together both bounds, unobserved heterogeneity in studies without imaging information can be described by a shape parameter in the range σ = 1-2. It substantially contributes to observed age-dependences of hazard ratios and may lead to underestimation of hazard ratios by a factor of about two. Therefore, analysis of studies for primary CHD risk assessment should account for unobserved heterogeneity.

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.

Comprehensive Management of Cardiovascular Risk Factors for Adults With Type 2 Diabetes: A Scientific Statement From the American Heart Association

Cardiovascular disease remains the leading cause of death in patients with diabetes. Cardiovascular disease in diabetes is multifactorial, and control of the cardiovascular risk factors leads to substantial reductions in cardiovascular events. The 2015 American Heart Association and American Diabetes Association scientific statement, "Update on Prevention of Cardiovascular Disease in Adults With Type 2 Diabetes Mellitus in Light of Recent Evidence," highlighted the importance of modifying various risk factors responsible for cardiovascular disease in diabetes. At the time, there was limited evidence to suggest that glucose-lowering medications reduce the risk of cardiovascular events. At present, several large randomized controlled trials with newer antihyperglycemic agents have been completed, demonstrating cardiovascular safety and reduction in cardiovascular outcomes, including cardiovascular death, myocardial infarction, stroke, and heart failure. This AHA scientific statement update focuses on (1) the evidence and clinical utility of newer antihyperglycemic agents in improving glycemic control and reducing cardiovascular events in diabetes; (2) the impact of blood pressure control on cardiovascular events in diabetes; and (3) the role of newer lipid-lowering therapies in comprehensive cardiovascular risk management in adults with diabetes. This scientific statement addresses the continued importance of lifestyle interventions, pharmacological therapy, and surgical interventions to curb the epidemic of obesity and metabolic syndrome, important precursors of prediabetes, diabetes, and comorbid cardiovascular disease. Last, this scientific statement explores the critical importance of the social determinants of health and health equity in the continuum of care in diabetes and cardiovascular disease.

Diabetic Retinopathy as a Predictor of Angiographic Coronary Atherosclerosis Severity in Patients with Type 2 Diabetes Mellitus

BACKGROUND

Diabetic retinopathy (DR) is one of the most prevalent consequences of diabetes mellitus (DM). Much emphasis has been focused on the link between DR and cardiovascular disorders in patients with type 2 diabetes (T2DM). However, there is little information about the relation between the degree of DR and coronary atherosclerosis severity in Egyptian patients.

AIM

To assess the correlation between the degree of DR and the coronary atherosclerosis severity in T2DM.

PATIENTS AND METHODS

This work included 140 diabetic patients with T2DM who underwent diagnostic coronary angiography because of suspected coronary artery disease (CAD). All participants were evaluated by history, fundus assessment, laboratory tests (lipid profile and glycated hemoglobin [HbA1c]), and selective coronary angiography. The severity of coronary artery lesion was detected by Gensini score and vessel score.

RESULTS

Patients with DR had a significantly higher Gensini score (67.86± 44.56 versus 5.93± 9.02, P < 0.001) and a vessel score (2.29± 0.86 versus 0.50± 0.66, P < 0.001). There was a significant relation between the degree of DR, Gensini score (P < 0.001), and vessel score (P < 0.001), as both scores increased according to the severity of DR. The presence and degree of retinopathy were the only independent factors linked to the severity score in multivariate linear regression analyses (P < 0.001).

CONCLUSION

The presence and degree of DR are independent predictors of severe coronary atherosclerosis. Therefore, when evaluating whether a patient with T2DM is at high risk for CAD, the DR degree should be taken into consideration.

Value of addition of coronary artery calcium to risk scores in the prediction of major cardiovascular events in patients with type 2 diabetes

BACKGROUND

The increased risk for cardiovascular events in diabetics is heterogeneous and contemporary clinical risk score calculators have limited predictive value. We therefore examined the additional value of coronary artery calcium score (CACS) in outcome prediction in type 2 diabetics without clinical coronary artery disease (CAD).

METHODS

The study examined a population-based cohort of type 2 diabetics (n = 735) aged 55-74 years, recruited between 2006 and 2008. Patients had at least one additional risk factor and no history or symptoms of CAD. Risk assessment tools included Pooled Cohort Equations (PCE) and Multi-Ethnic Study of Atherosclerosis (MESA) 10-year risk score calculators and CACS. The occurrence of myocardial infarction (MI), stroke or cardiovascular death (MACE) was assessed over 10-years.

RESULTS

Risk score calculators predicted MACE and MI and cardiovascular death individually but not stroke. Increasing levels of CACS predicted MACE and its components independently of clinical risk scores, glycated hemoglobin and other baseline variables: hazard ratio (95% confidence interval) 2.92 (1.06-7.86), 6.53 (2.47-17.29) and 8.3 (3.28-21) for CACS of 1-100, 101-300 and > 300 Agatston units respectively, compared to CACS = 0. Addition of CACS to PCE improved discrimination of MACE [AUC of PCE 0.615 (0.555-0.676) versus PCE + CACS 0.696 (0.642-0.749); p = 0.0024]. Coronary artery calcium was absent in 24% of the study population and was associated with very low event rates even in those with high estimated risk scores.

CONCLUSIONS

CACS in asymptomatic type 2 diabetics provides additional prognostic information beyond that obtained from clinical risk scores alone leading to better discrimination between risk categories.

Relation between Baseline Coronary Atherosclerotic Status, Cardiovascular Events, and Malignancies in Type 2 Diabetics: A Long-Term Prospective Cohort Study

INTRODUCTION

Coronary artery disease and malignancy occur more frequently in patients with type 2 diabetes. They may share inflammation as a possible common pathogenetic mechanism, but it is unclear whether a clinical correlation exists between them.

METHODS

This prospective cohort study followed 735 asymptomatic diabetics, aged 63.4 ± 5.3 years (mean ± standard deviation) for 12.2 ± 0.6 years after baseline coronary artery calcium scoring and cardiac computed tomography angiography. We examined extent and nature of coronary atherosclerosis and incidence of clinical cardiovascular (CV) events (death or myocardial infarction) and sought a relation to incidence of malignancy and malignancy mortality.

RESULTS

Total mortality was 16.5% (121/735 patients): malignancy was cause of death in 48/121 (39.7%) of these and CV events in 44/121 (36.3%). There was no relation between extent of coronary atherosclerosis and incident malignancy (plaque volume 127 [21, 427] mm3 (median [interquartile range]) for incident malignancy versus 153 [24, 427] mm3 no malignancy, p = 0.71) or death from malignancy (plaque volume 176 [26, 646] versus 144 [22, 411] mm3, p = 0.32). There was also no relation between presence of high-risk plaque and incident malignancy (high-risk plaque in 27.1% with malignancy vs. 21.6% without, p = 0.18) or fatal malignancy (p = 0.16). Incident and fatal malignancy were not related to clinical CV events. Independent predictors of incident and fatal malignancy were age, smoking at baseline, and elevated C-reactive protein.

CONCLUSION

This study found no relation between extent of coronary atherosclerosis or incidence of CV events and malignancy. Malignancy surpassed CV disease as the commonest long-term cause of mortality in middle-aged and older diabetics.

Practice Pattern, Diagnostic Yield, and Long-Term Prognostic Impact of Coronary Computed Tomographic Angiography

Background Although guidelines recommend the use of coronary computed tomographic angiography (CTA) in patients with stable pain syndromes, the clinical benefits of the use of coronary CTA in a broad spectrum of patients is unknown. We evaluated the contemporary practice pattern and diagnostic yield of coronary CTA and their impact on the subsequent diagnostic-therapeutic cascade and clinical outcomes. Methods and Results We identified 39 906 patients without known coronary artery disease (CAD) who underwent coronary CTA between January 2007 and December 2013. The patients' demographic characteristics, risk factors, symptoms, results of coronary CTA, the appropriateness of downstream diagnostic and therapeutic interventions, and long-term outcomes (death or myocardial infarction) were evaluated. The number of coronary CTAs had increased over time, especially in asymptomatic patients. Coronary CTA revealed that 6108 patients (15.3%) had obstructive CAD (23.7% of symptomatic and 9.3% of asymptomatic patients). Subsequent cardiac catheterization was performed in 19.2% of symptomatic patients (appropriate, 80.6%) and in 3.9% of asymptomatic patients (appropriate, 7.9%). The 5-year rate of death or myocardial infarction was significantly higher in patients with obstructive CAD on CTA than those without (7.2% versus 3.0%; P<0.001; adjusted hazard ratio [95% CI], 1.34 [1.17-1.54]). However, obstructive CAD on CTA had limited added value over conventional risk factors for predicting death or myocardial infarction. Conclusions Although the use of coronary CTA had substantially increased, CTA had a low diagnostic yield for obstructive CAD, especially in asymptomatic patients. The use of CTA in asymptomatic patients seemed to have led to inappropriate subsequent diagnostic or therapeutic interventions without clinical benefit.

Recent Updates on Vascular Complications in Patients with Type 2 Diabetes Mellitus

It is well known that patients with type 2 diabetes mellitus (T2DM) are at an increased risk of morbidity and mortality from atherosclerotic cardiovascular (CV) complications. Previously, the concept that diabetes mellitus (DM) is a "coronary artery disease (CAD) risk equivalent" was widely accepted, implying that all DM patients should receive intensive management. However, considerable evidence exist for wide heterogeneity in the risk of CV events among T2DM patients and the concept of a "CAD risk equivalent" has changed. Recent guidelines recommend further CV risk stratification in T2DM patients, with treatment tailored to the risk level. Although imaging modalities for atherosclerotic cardiovascular disease (ASCVD) have been used to improve risk prediction, there is currently no evidence that imaging-oriented therapy improves clinical outcomes. Therefore, controversy remains whether we should screen for CVD in asymptomatic T2DM. The coexistence of T2DM and heart failure (HF) is common. Based on recent CV outcome trials, sodium glucose cotransporter-2 inhibitors and glucagon like peptide-1 receptor agonists are recommended who have established ASCVD, indicators of high risk, or HF because of their demonstrated benefits for CVD. These circumstances have led to an increasing emphasis on ASCVD and HF in T2DM patients. In this review, we examine the literature published within the last 5 years on the risk assessment of CVD in asymptomatic T2DM patients. In particular, we review recent guidelines regarding screening for CVD and research focusing on the role of coronary artery calcium, coronary computed tomography angiography, and carotid intima-media thickness in asymptomatic T2DM patients.

Coronary artery disease (CAD) extension-derived risk stratification for asymptomatic diabetic patients: usefulness of low-dose coronary computed tomography angiography (CCTA) in detecting high-risk profile patients

BACKGROUND

As one of the most frequent risk factors for cardiovascular disease, type 2 diabetes mellitus (T2DM) is one of the largest causes of death. However, an acute cardiac presentation is not uncommon in diabetic patients, and the current investigative approach remains often inadequate. The aim of our study was to retrospectively stratify the risk of asymptomatic T2DM patients using low-dose 640-slice coronary computed tomography angiography (CCTA).

MATERIALS AND METHODS

CCTA examinations of 62 patients (mean age, 65 years) with previous diagnosis of type 2 diabetes and without cardiac symptoms were analyzed. Image acquisition was performed using a 640-slice CT. Per-patient, per-vessel and per-plaque analyses were performed. Stratification risk was evaluated according to the ESC guidelines. The patients were followed up after 2.21 ± 0.56 years from CCTA examination.

RESULTS

Coronary artery disease (CAD) was found in 58 patients (93.55%) presenting 290 plaques. Analysis of all samples showed severe-to-occlusive atherosclerosis in 24 patients (38.7% of cases). However, over the degree of stenosis, 23 patients were evaluated at high risk considering the extension of CAD. Good agreement was shown by the correlation of CAD extension/risk estimation and MACE incidence, according to a Kaplan-Meier survival analysis (p value = 0.001), with a 7.25-fold increased risk (HR 7.25 CI 2.13-24.7; p value = 0.002).

CONCLUSION

Our study confirms the high capability of CCTA to properly stratify the CV risk of asymptomatic T2DM patients. Its use could be recommended if we consider how current investigative strategies to correctly assess these patients often seem inadequate.

Screening and Risk Assessment of Coronary Artery Disease in Patients With Type 2 Diabetes: An Updated Review

Current literature indicates that there is a strong correlation between coronary artery disease (CAD) and type 2 diabetes. The arteriosclerotic progression occurs earlier and in a greater extent in the diabetic than in the non-diabetic population. In diabetic subjects, the detection of arterial disease does not always precede the development of an acute arterial incident. Herein, we reviewed studies published within the last 5 years in order to reveal the risk factors for coronary artery disease in patients with type 2 diabetes. In addition, we aimed to discuss how to diagnose in an early stage or even screen the presence of coronary artery disease in asymptomatic diabetic patients. Possible blood markers as predictors of CAD, which are mostly related to the lipidemic profile of subjects, are included in this review. Less invasive imaging methods than conventional coronary angiography, included in the article, are gradually used more in the diagnosis of CAD and show high effectiveness. Data from 23 articles with 22,350 patients having type 2 diabetes were summarized and presented descriptively.

Diabetic retinopathy as an independent predictor of subclinical cardiovascular disease: baseline results of the PRECISED study

OBJECTIVE

Detection of subclinical cardiovascular disease (CVD) has significant impact on the management of type 2 diabetes. We examined whether the assessment of diabetic retinopathy (DR) is useful for identifying patients at a higher risk of having silent CVD.

RESEARCH DESIGN AND METHODS

Prospective case-control study comprising 200 type 2 diabetic subjects without history of clinical CVD and 60 age-matched non-diabetic subjects. The presence of subclinical CVD was examined using two parameters: (1) calcium coronary score (CACs); (2) composite of CACs >400 UA, carotid plaque ≥3 mm, carotid intima-media thickness ratio >1, or the presence of ECG changes suggestive of previous asymptomatic myocardial infarction. In addition, coronary angio-CT was performed. DR was assessed by slit-lamp biomicroscopy and retinography.

RESULTS

Type 2 diabetic subjects presented higher CACs than non-diabetic control subjects (p<0.01). Age, male gender, and the presence of DR were independently related to CACs >400 (area under the receiver operating characteristic curve (AUROC) 0.76). In addition, an inverse relationship was observed between the degree of DR and CACs <10 AU. The variables independently associated with the composite measurement of subclinical CVD were age, diabetes duration, the glomerular filtration rate, microalbuminuria, and the presence of DR (AUROC 0.71). In addition, a relationship (p<0.01) was observed between the presence and degree of DR and coronary stenosis.

CONCLUSIONS

The presence and degree of DR is independently associated with subclinical CVD in type 2 diabetic patients. Our results lead us to propose a rationalized screening for coronary artery disease in type 2 diabetes based on prioritizing patients with DR, particularly those with moderate-severe degree.

Predictive value of coronary computed tomography angiography in asymptomatic individuals with diabetes mellitus: Systematic review and meta-analysis

BACKGROUND

Coronary CT angiography (CTA) is generally not established as a screening tool for asymptomatic individuals. However, it is controversial whether this test may have a role for screening asymptomatic individuals with diabetes mellitus (DM) due to the high prevalence of asymptomatic coronary artery disease (CAD) in this subgroup.

METHODS

We searched PubMed and EMBASE through May 2017 for studies that reported on the association between findings at coronary CTA and future cardiac events in asymptomatic individuals with DM. Summary hazard ratios for the presence of obstructive CAD (≥50% stenosis), presence of non-obstructive plaque (<50% stenosis), segment involvement score, and segment stenosis score were derived using a random effects regression model. I² was calculated to quantify between-study heterogeneity and causing factors were identified using meta-regression.

RESULTS

A total of 10 studies reporting on 5012 individuals with DM (median age: 62.3 years, median proportion of women: 40.5%) were included in the analysis. The presence of obstructive CAD on coronary CTA (vs. non-obstructive or no CAD) was associated with a significantly elevated risk for adverse events (summary HR: 4.07, 95% CI: 2.30 to 7.21). The estimated summary HR for non-obstructive plaque (vs. no CAD) was 2.17 (95% CI: 1.11 to 4.25). The pooled HRs per unit for segment stenosis score and segment involvement score were 1.44 (95% CI: 0.98 to 2.12), and 1.73 (95% CI: 1.07 to 2.80) respectively. On meta-regression analysis, we observed a trend towards a higher risk estimate in studies with a higher proportion of females (p = 0.1063).

CONCLUSION

The presence and extent of CAD on coronary CTA are strong, independent predictors of cardiovascular events in asymptomatic individuals with DM despite heterogeneity between studies in endpoints, study population and length of follow-up.

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

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

Cardiac Computed Tomography Angiographic Findings as Predictors of Late Heart Failure in an Asymptomatic Diabetic Cohort: An 8-Year Prospective Follow-Up Study

OBJECTIVES

Predictive models for heart failure (HF) in heterogeneous populations have had limited success. We examined cardiac computed tomography angiography (CTA) predictors of HF or cardiovascular death (HF-CVD) in a prospective study of asymptomatic diabetics undergoing baseline assessment by CTA.

METHODS

The subjects (n = 735, aged 55-74 years, 51.2% women) had no clinical history of cardiovascular disease at study entry. Coronary artery calcium (CAC) score, CTA-defined coronary atherosclerosis, cardiac chamber volumes, and clinical data were collected and late outcome events recorded over 8.4 ± 0.6 years (range 7.3-9.3).

RESULTS

HF-CVD occurred in 41 (5.6%) subjects, with HF occurring mostly (19/23, 82.6%) in subjects without preceding myocardial infarction. Baseline univariate clinical outcome predictors of HF-CVD included older age (p = 0.027), the duration of diabetes (p = 0.004), HbA1c (p < 0.0001), microvascular disease (retinopathy, microalbuminuria) (p < 0.0001), and systolic blood pressure (p = 0.035). Baseline univariate CTA predictors included CAC score (p = 0.004), coronary stenosis (p = 0.047), and a CTA-defined left/right atrial (LA/RA) volume ratio >1 (p < 0.0001). Independent predictors were an LA/RA volume ratio >1, microvascular disease, and systolic blood pressure (model C-statistic 0.792, 95% CI 0.758-0.824). Measures of the extent of coronary artery disease (CAD) were not independent predictors of HF-CVD.

CONCLUSIONS

In a low- to moderate-risk asymptomatic diabetic population, CTA LA enlargement (LA/RA volume ratio) but not the extent of CAD had independent prognostic value for HF-CVD in addition to the clinical variables.