Objectives: Diabetes mellitus is considered as an equivalent of coronary artery disease (CAD). Aim of the study was to investigate whether in asymptomatic patients with type II diabetes, diastolic stress echocardiography may represent an alternative tool for the detection of CAD.
Methods: The study population consisted of 105 patients with diabetes mellitus (age 61+/-9 years, 26% female, duration of diabetes 37+/-14 months). We performed an exercise stress test, followed by an echo-study and a single-positron emission tomography. Coronary angiography was performed within 1 month.
Results: Coronary angiography revealed a coronary artery stenosis of at least 70% in 72 patients (69%, CAD group), while the remaining formed the non-CAD group. Exercise induced an increase of both E/E' lateral and septal ratios as well as their average in the CAD group and on the contrary a decrease of these ratios in the non-CAD group. Receiver operating curve analysis for discrimination between patients with and without obstructive CAD showed an optimal cut-off value of -0.0708 for the exercise-induced change of E/E' average (area under curve 0.892, P<0.001). Sensitivities of scintigraphy and of diastolic stress echocardiography for detection of CAD were 75.0 and 93.1%, respectively; specificity was 78.8% for both methods. In asymptomatic patients, sensitivities of scintigraphy and diastolic stress echocardiography were 76.9 and 92.3%; specificity of both was 80%.
Conclusion: In patients with type II diabetes, diastolic stress echocardiography, by means of E/E' ratio exercise-induced changes, can be used for the diagnosis and severity of CAD and for the detection of occult myocardial ischemia.