Risk stratification in uncomplicated type 2 diabetes: prospective evaluation of the combined use of coronary artery calcium imaging and selective myocardial perfusion scintigraphy.
OBJECTIVE
To determine the prevalence and clinical predictors of subclinical atherosclerosis and myocardial ischaemia in uncomplicated type 2 diabetes and assess their relationship to short-term outcome.


RESULTS
Established risk factors and coronary artery calcium (CAC) scores were prospectively measured in 510 asymptomatic type 2 diabetic subjects (mean age 53+/-8 years, 61% males) without prior cardiovascular disease. Myocardial perfusion scintigraphy (MPS) was performed in all subjects with CAC > 100 Agatston units (AU) (n=127), and a random sample of the remaining patients with CAC < or = 100 AU (n=53). Significant CAC (> 10 AU) was found in 46.3%. Twenty events occurred (two coronary deaths, nine non-fatal myocardial infarctions, three acute coronary syndromes, three non-haemorrhagic strokes, and three late revascularisations) during a median follow-up of 2.2 years (25th-75th percentile = 1.9-2.5 years). The age, systolic blood pressure, the duration of diabetes, United Kingdom Prospective Diabetes Study risk score, CAC score, and extent of myocardial perfusion abnormality were significant predictors of time to cardiovascular events in a univariable Cox proportional hazard model. No cardiac events or perfusion abnormalities occurred in subjects with CAC < or = 10 AU up until 2 years of follow-up. CAC and MPS findings were synergistic for the prediction of short-term cardiovascular events.


CONCLUSIONS
Subclinical atherosclerosis, measured by CAC imaging, is superior to the established cardiovascular risk factors for predicting silent myocardial ischaemia and short-term outcome. Further studies evaluating the impact of CAC imaging on clinical outcomes and its cost effectiveness are warranted.
Cardiac Imaging and Research Centre, Wellington Hospital (South), Wellington Place, St John's Wood, London NW8 9LE, UK. vdanand@hotmail.com
Dhakshinamurthy Vijay
DV
Anand
Eric
E
Lim
David
D
Hopkins
Roger
R
Corder
Leslee J
LJ
Shaw
Patrick
P
Sharp
David
D
Lipkin
Avijit
A
Lahiri
D002114:Calcinosis / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D012307:Risk Factors