Screening subclinical coronary artery disease with noninvasive modalities in patients with diabetes

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.

Cardiovascular risk assessment and screening in diabetes

Diabetes used to be considered as a coronary heart disease equivalence and universally classified high cardiovascular risk population. However increasing epidemiological evidence now indicates the heterogeneity of risk among the diabetic patients and imposes animportance of stratifying those with relative low-risk from high-risk ones. Despite the existing risk assessment tools, current cardivoascualr disease prevention guidelines fail to provide more detailed stratification strategies for patient with diabetes and expose them to either overtreatment or undertreatment. On the other hand, various screening modality, including novel biomarkers and subclinical asthrosclerosis scanning, including coronary calcium scanning, carotid intima-media thickness, myocardial perfusion imaging and coronary computed tomography angiography, have provided very promising usage is risk stratification. With better developed test techniques and more extensive evidence, these modalities may serve in standardized screening algorithm to improve the cardiovascular risk assessment of patients with diabetes and better instruct their individualized preventive therapy.