OBJECTIVE -Silent myocardial ischemia (SMI) in asymptomatic subjects with no history of myocardial infarction or angina is a frequent condition in diabetic patients. The aim of the study was to examine the predictive value of SMI for cardiac events in a multicenter cohort and to determine whether this value is higher in patients with a particular clinical profile. RESEARCH DESIGN AND METHODS-A total of 370 asymptomatic diabetic patients with at least two additional cardiovascular risk factors was recruited in four departments of diabetology. SMI was assessed by either exercise or dipyridamole single-photon emissioncomputed tomography myocardial perfusion imaging with thallium-201. If dipyridamole stress was used, an electrocardiogram stress test was performed separately on another day. Follow-up duration was 3-89 months (38 Ϯ 23 months).RESULTS -There was evidence of SMI in 131 patients (35.4%) on at least one positive noninvasive test. The patients with SMI were significantly older and had significantly higher serum triglycerides and lower HDL cholesterol levels. Cardiac events occurred in 53 patients (14.3%). Major cardiac events (death or myocardial infarction) occurred in 38 patients (10%) and other events (unstable angina, heart failure, or coronary revascularization) occurred in 15 patients. The patients who had cardiac events were older and had higher serum triglyceride levels at baseline. There was a significant association between SMI and cardiac events (hazard ratio 2.79 [95% CI 1.54 -5.04]) and in particular major cardiac events (3 [1. 53-5.87]). In the patients Ͼ60 years of age, the prevalence of SMI was higher (43.4 vs. 30.2% in those Ͻ60 years). SMI was associated with a significant risk of cardiac events (2.89 [1.31-6.39]) and in particular major cardiac events (3.66 [1.36 -9.87]) for the patients Ͼ60 years old but not for those Ͻ60 years old. CONCLUSIONS -In asymptomatic diabetic patients with additional cardiovascular risk factors, SMI is a potent predictor of cardiac events and should be assessed preferably in the patients Ͼ60 years of age. Diabetes Care 28:2722-2727, 2005T he prognostic value of type 1 silent myocardial ischemia (SMI) according to the Cohn classification, i.e., myocardial ischemia in asymptomatic subjects with no history of myocardial infarction or angina (1), has been evaluated in several studies in the general population. One of them had included 2,014 asymptomatic men whose mean age was 50 years and showed that within 13 years of follow-up, the rate of major cardiac events was four to five times higher in the patients with a positive exercise electrocardiogram (ECG) test than in those with a normal ECG stress test (2). Other studies have shown that a positive exercise ECG test predicts a 3-14 times higher rate of major cardiac events (3,4). Silent ischemic episodes during 24-h ECG monitoring have also been shown to be associated with a higher rate of major cardiac events in patients who suffer from unstable angina, myocardial infarction, or ECG ischemic changes at low level...