Evaluation of the predictive value of coronary artery calcium score for obstructive coronary artery disease in asymptomatic Korean patients with type 2 diabetes mellitus

Simplified Approach to Predicting Obstructive Coronary Disease With Integration of Coronary Calcium: Development and External Validation

BACKGROUND

The Diamond-Forrester model was used extensively to predict obstructive coronary artery disease (CAD) but overestimates probability in current populations. Coronary artery calcium (CAC) is a useful marker of CAD, which is not routinely integrated with other features. We derived simple likelihood tables, integrating CAC with age, sex, and cardiac chest pain to predict obstructive CAD.

METHODS AND RESULTS

The training population included patients from 3 multinational sites (n=2055), with 2 sites for external testing (n=3321). We determined associations between age, sex, cardiac chest pain, and CAC with the presence of obstructive CAD, defined as any stenosis ≥50% on coronary computed tomography angiography. Prediction performance was assessed using area under the receiver-operating characteristic curves (AUCs) and compared with the CAD Consortium models with and without CAC, which require detailed calculations, and the updated Diamond-Forrester model. In external testing, the proposed likelihood tables had higher AUC (0.875 [95% CI, 0.862-0.889]) than the CAD Consortium clinical+CAC score (AUC, 0.868 [95% CI, 0.855-0.881]; P=0.030) and the updated Diamond-Forrester model (AUC, 0.679 [95% CI, 0.658-0.699]; P<0.001). The calibration for the likelihood tables was better than the CAD Consortium model (Brier score, 0.116 versus 0.121; P=0.005).

CONCLUSIONS

We have developed and externally validated simple likelihood tables to integrate CAC with age, sex, and cardiac chest pain, demonstrating improved prediction performance compared with other risk models. Our tool affords physicians with the opportunity to rapidly and easily integrate a small number of important features to estimate a patient's likelihood of obstructive CAD as an aid to clinical management.

Influence of the Triglyceride-Glucose Index on Adverse Cardiovascular and Cerebrovascular Events in Prediabetic Patients With Acute Coronary Syndrome

BACKGROUND

Cardiovascular disease and insulin resistance are closely related. The triglyceride-glucose (TyG) index is frequently used as an indicator of insulin resistance. However, there is scant information on the TyG index in the prediabetic population, nor is the prognostic significance of the index known for prediabetes and acute coronary syndrome (ACS) patients.

METHODS

The clinical endpoint was a major adverse cardiovascular and cerebrovascular event (MACCEs), including cardiac-related death, non-fatal myocardial infarction, ischemia-driven revascularization, and stroke. The TyG index was calculated as = ln [(triglyceride level, mg/dL) × (glucose level, mg/dL)÷2] under fasting conditions.

RESULTS

The study included 2,030 prediabetic patients with ACS. Patients were followed up for 2.5 years, during which the total incidence of MACCEs was 12%. After adjustment for covariates, the TyG index was found to be predictive of prediabetes with ACS (HR 4.942, 95%CI: 3.432-6.115, P<0.001). Using propensity score matching, 574 pairs were successfully matched, and the two groups were analyzed in terms of survival. This showed that there was a significantly greater incidence of MACCEs in patients with high TyG indices (HR 3.526, 95%CI: 2.618-4.749, P<0.001), mainly due to ischemia-driven revascularization and stroke.

CONCLUSIONS

The TyG index independently predicts future MACCEs and may be an important prognostic indicator for patients with prediabetes and ACS.

Multisite atherosclerosis in subjects with metabolic syndrome and diabetes and relation to cardiovascular events: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

The extent and relation of multisite atherosclerosis to cardiovascular disease (CVD) in metabolic syndrome (MetS) and diabetes (DM) are not well documented. We examined the extent of multisite atherosclerosis and its prognostic value for CVD events in MetS and DM.

METHODS

In CVD-free subjects from the Multi-Ethnic Study of Atherosclerosis, multisite atherosclerosis was measured as: (1) the number of arterial beds involved (coronary calcium>0, abdominal aortic calcium>0, carotid intima-media thickness ≥1 mm and ankle brachial index<1 or ≥1.4); (2) a composite score summing the quartile rank for each atherosclerosis measure. Hazard ratios (HRs) and c-statistics were calculated for incident CVD and coronary heart disease (CHD) over 10.6 years.

RESULTS

Of 1675 individuals (mean age 64 years, 51% male), 33.4% had MetS and 15.9% had DM. The number of atherosclerotic sites was higher in those with DM (mean ± SD = 1.67 ± 1.15) and MetS (1.49 ± 1.12) versus neither MetS/DM (1.09 ± 1.09) (p < 0.0001). CVD rates per 1000 person-years ranged from 3.5, 8.2, and 10.0 in those with 0 sites positive to 35.1, 79.6 and 103.4 in those with 4 sites positive among neither DM/MetS, MetS and DM groups, respectively. HRs (95% CI) for CVD comparing those with 4 vs. 0 atherosclerotic sites were 4.0 (0.8-19.1), 4.9 (2.0-12.0), and 14.4 (3.6-57.6), respectively. C-statistics adding multisite atherosclerosis measures increased over models without the measures and with CIMT or ABI but not CAC.

CONCLUSIONS

Multisite atherosclerosis is greater with MetS or DM, and predicts CVD and CHD events. Risk prediction is improved over CIMT and ABI but not CAC.

Impact of optimal glycemic control on the progression of coronary artery calcification in asymptomatic patients with diabetes

BACKGROUND

Data on the impact of optimal glycemic control (OGC) on the progression of coronary artery calcification, an important marker for future adverse cardiovascular events in individuals with diabetes are limited.

METHODS

We investigated 1637 asymptomatic adults with diabetes (56 ± 8 years, 88.8% men) and no history of coronary artery disease or stroke, who underwent serial coronary artery calcium (CAC) screening. The median inter-scan period was 3.0 (2.0-4.4) years. The change in CAC was compared base on OGC status. OGC was defined as a follow-up hemoglobin A1C (HbA1C) of <7.0%, and CAC progression was defined by a square root (√) transformed difference between the baseline and follow-up CAC scores (Δ √transformed CAC) of ≥2.5.

RESULTS

Despite no significant difference in the baseline CAC scores, the incidence of CAC progression was lower in the OGC group than in the non-OGC group (45.4% vs. 51.7%; p < 0.013). The two groups differed in the Δ √transformed (OGC, 3.8 ± 6.4; non-OGC, 4.7 ± 6.9; p = 0.016) and annualized Δ √transformed CAC (OGC, 1.1 ± 2.4; non-OGC, 1.4 ± 2.6; p = 0.010) scores. Subgroup analysis showed that OGC significantly reduced the risk of CAC progression in patients aged <65 years and in: smokers, and patients with a body mass index of <25 kg/m², dyslipidemia, and baseline CAC scores between 1-100 and >400. In multivariate regression analysis, OGC was independently associated with a reduced risk of CAC progression (odds ratio, 0.745, 95% confidence interval, 0.601-0.924; p = 0.007).

CONCLUSION

OGC attenuated the progression of coronary artery calcification in asymptomatic patients with diabetes.

The relationship of insulin resistance estimated by triglyceride glucose index and coronary plaque characteristics

The triglyceride glucose (TyG) index is a useful surrogate marker for insulin resistance, which is an important risk factor for coronary artery disease (CAD). However, data on the relationship of the TyG index and coronary plaque characteristics are limited.This study included 2840 participants with near-normal renal function who underwent coronary computed tomography angiography. CAD was defined as the presence of any plaques, and obstructive CAD was defined as the presence of plaques with ≥50% stenosis. The relationship between the TyG index and noncalcified plaque (NCP), calcified or mixed plaque (CMP), and coronary artery calcium score (CACS) was evaluated.All participants were stratified into 4 groups based on the quartiles of the TyG index. The prevalence of CAD and obstructive CAD significantly increased with increasing quartiles. The risk for NCP and obstructive NCP was not different among all groups. However, compared with group I (lowest quartile), the risk for CMP was higher in groups III (odds ratio [OR]: 1.438) and IV (highest quartile) (OR: 1.895) (P < .05), and that for obstructive CMP was higher in groups II (OR: 1.469), III (OR: 1.595), and IV (OR: 2.168) (P < .05). Multivariate regression analysis showed that the TyG index was associated with an increased risk for CAD (OR: 1.700), obstructive CAD (OR: 1.692), and CACS >400 (OR: 1.448) (P < .05).The TyG index was independently associated with the presence and severity of CAD due to an increased risk for CMP.

Should adults with type 2 diabetes be screened for atherosclerotic cardiovascular disease?

Diabetes mellitus is associated with greater risks for cardiovascular diseases (CVD). Multiple noninvasive screening tools for CVD including cardiac CT, carotid intima-media thickness test, myocardial perfusion imaging have been examined in those with diabetes, but the prognostic value of these tests vary and issues remain regarding their cost-benefit ratios, potential harms of radiation, and how they fit into screening algorithms for CVD. We discuss in this report the needs and criteria for screening tests and summarize the evidence from observational studies and clinical trials. We also explore whether there should be more sensitive screening modalities to better detect both short and long-term cardiovascular risk among asymptomatic patients with diabetes.