The utility of stress testing modalities for asymptomatic diabetic patients remains an area of active interest and study. Diabetic patients have significantly higher rates of silent ischemia than the general population, and that could in part explain the more advanced CAD seen on initial presentation and the worse outcomes in these patients [
20]. The absence of myocardial ischemia on noninvasive tests of patients with DM does not necessarily identify a lower-risk cohort. In the present study most of patients (250) had a negative stress echo and presented 4.8 % of cardiovascular event during the follow-up period. This may be related, at least in part, to the observation that diffuse coronary dysfunction in diabetic patients precedes overt atherosclerosis and regional wall motion abnormalities of the left ventricle are harder to identify by stress echocardiography, because the reduced perfusion is global instead of regional [
1,
8‐
13]. Thus, the current guidelines recommend that all diabetic patients should be treated as if they have CAD with regard to blood pressure management, lipid-level goals, and other secondary preventive measures. Clinicians should make efforts to stratify the long-term risk of CAD-associated morbidity and mortality in diabetic patients in order to identify those patients who need more aggressive treatment strategies. The guidelines of the American College of Cardiology/American Heart Association and the American Diabetes Association recommend screening for CAD in diabetic patients with an abnormal resting EKG indicating myocardial infarction, with carotid or peripheral arterial disease, symptoms suggesting CAD, or 2 or more cardiovascular risk factors irrespective of the presence of CAD symptoms [
21‐
22]. However, as seen in this study, these guidelines do not seem to satisfy physicians regarding the risk stratification of diabetic patients. Our results showed that 25 % of patients underwent pharmacological stress echocardiography with the only indication being that they had DM and stress echo is a safe procedure [
23]. The annual rate of hard events occurring in diabetic patients with a normal stress echocardiogram ranges from 1.6 % to 6 %, whereas the corresponding rate in nondiabetic patients ranges from 0.6 % to 2.7 %. In addition, in patients with DM the event rate increases sharply in the second year after the procedure [
24]. In our study, 4.8 % of patients had an event during a mean follow-up period of 18 ± 14 months in patients with a negative stress test, most occurring 1 year after the test. By contrast, among those patients with a positive stress test, there were about 4-fold more events during a mean follow-up of 13 ± 13 months. These findings are similar to other studies [
12,
25‐
26]. Cortigiani et al. [
5] compared the prognostic value of pharmacologic stress echocardiography in chest pain patients with and without DM, (mean age 60 ± 10 years) and positive exercise electrocardiography. During a median follow-up of 26 months, the results of stress echocardiography added prognostic value to the positive exercise electrocardiography results. Both diabetic and nondiabetic patients with nonischemic stress echocardiography results had lower annual rates of major events compared with the overall population of diabetic and nondiabetic patients with positive electrocardiography results. However, in our study, most patients did not undergo exercise stress testing before pharmacological stress echocardiography. Patients referred for pharmacological stress echocardiography have been found to have a higher risk for cardiovascular events than those referred for exercise testing, which likely reflects more severe underlying cardiovascular disease and comorbidities [
12]. When our patients were asked why they did not undergo an EKG exercise stress test before the pharmacological stress test, most answered that their private physician asked directly for a pharmacological test regardless of whether they could undergo an exercise test. Of the 70 patients who underwent exercise EKG testing before pharmacological echocardiography only 1 had a positive dipyridamole stress test and we found only three cardiovascular events during the follow-up period in these patients. It appears that physicians simply do not believe that an exercise test is adequate for stratifying their diabetic patients. In our study, the time to occurrence of cardiovascular events was significant shorter in patients with a positive echocardiography stress test compared to patients with a negative stress test (13.7 ± 13.2 versus 20.7 ± 16.6 months, respectively). However, most cardiovascular events, regardless of the results of stress testing, occurred around 18 months after the procedure, which suggests that patients with DM should undergo another imaging stress test 12 months after their first test. In a study assessing long-term outcomes of patients with diabetes (N = 230) and limited exercise capability, dobutamine stress echocardiography provided prognostic value for about 7 years after the initial test [
27]. However, in both that study and our study, the lack of data on the duration of diabetes is an important shortcoming. In addition, the socioeconomic background of the 2 study cohorts may be different, and that factor can affect the prognosis and evaluation of the disease.