|ISSN No. 1606-7754 Vol.14 No.3 December 2006|
Assessing the prevalence, quantification and morphological composition of coronary atherosclerosis in patients with type 2 diabetes and the metabolic syndrome via 64-Slice CT angiography
Jeffrey J Fine, Ali A Rizvi
Department of Investigator Initiated Research, South Carolina Heart Center, PA 63 Lawrin Ct., USA
Background: We determined the prevalence, morphology, and severity of coronary artery plaque in high-risk patients via 64-slice cardiovascular computed tomography (CVCT). Methods: Based on chart review, 101 subjects having a 64-slice CVCT were assigned to one of three groups: type 2 diabetes, metabolic syndrome, or comparison. Disease severity was classified as: no disease, subclinical disease (lesions <70%), or clinically significant disease (lesions >70%). Plaque morphology was stratified as either vulnerable or stable plaque by Houndsfield units and established American Heart Association criteria. Results: Diabetic subjects had the highest prevalence of CAD (78%), compared to 65% in the metabolic syndrome subjects and 55% in the comparison group (p<.05). Diabetic subjects were also most likely to have both significant CAD (41%), and stable plaque (52%) followed by metabolic syndrome subjects (33% and 25%) and the comparison group (15% and 20%) (p < 0.05). The metabolic syndrome group was most likely to have vulnerable lesions (36%) potentially placing them at increased risk of acute events. 22% of subjects in the diabetes group, 35% in the metabolic syndrome group, and 45% in the comparison cohort were disease-free. Conclusions: 64-slice CVCT allows non-invasive diagnosis and stratification of subjects with diabetes and the metabolic syndrome, providing relevant information regarding coronary disease prevalence, severity, and plaque composition, that are statistically different among these high risk patient cohorts. (Int J Diabetes Metab 14: 120-125, 2006)
Key words: cardiovascular computed tomography, diabetes, metabolic syndrome, coronary atherosclerosis
Over the last 50 years, the incidence and prevalence of coronary artery disease (CAD) have climbed steadily in the majority of westernised countries.1 Statistics also reveal that human society is in the midst of an epidemic of obesity-related disorders and type 2 diabetes.2 The entities of pre-diabetes and the metabolic syndrome are three times as common,3 and are believed to increase the risk of progression to type 2 diabetes and cardiovascular disease. The latter remains the primary cause of diabetes-associated morbidity and mortality, as more than two-thirds of people with diabetes die of heart or vascular disease.1 The impact of diabetes on cardiovascular disease is further illustrated by the fact that the risk of developing a myocardial infarction in diabetic patients without known heart disease is equivalent to the risk observed in non-diabetic survivors of a prior infarction.4
Because of the high incidence of CAD among diabetic patients, the need for accurate and early identification is paramount. CT angiography has received a boost recently with the availability of the 64-slice CT scanner. The latest generation of CT scanners can provide exquisite imaging of cardiac structures, coronary plaque morphology data, and details of atherosclerotic lesions quickly and with minimal patient discomfort or risk.
We undertook a retrospective review of patients who underwent cardiovascular CT (CVCT) angiography at the South Carolina Heart Center from the time of acquisition of the machine in December 2004 to the present. The objectives of this study were to determine the prevalence and severity of coronary atherosclerosis between nondiabetic patients, subjects with type 2 diabetes, and those with the metabolic syndrome. We also sought to determine if coronary plaque morphology, composition, and characteristics varied between the three groups.