Stress myocardial scintigraphy and dobutamine echocardiography in the detection of coronary disease in asymptomatic patients with type 2 diabetes

Abstract

Objective: The aims of this prospective study were: (1) to compare stress thallium-201 single photon emission computed tomography (SPECT) and dobutamine echocardiography (DE) in the detection of silent myocardial ischemia (SMI) in asymptomatic high risk diabetic patients; (2) to analyse long-term outcome after intensive care of SMI in these patients.

Methods: SPECT was performed in 100 high risk diabetic patients and DE in the first 75 patients. Coronary angiography was realized in patients with SMI, with revascularization for suitable lesions. Intensive treatment of atherosclerosis risk factors was performed in all patients. Patients were followed 2 +/- 0.5 years for the subsequent occurrence of cardiac death, myocardial infarction and revascularization.

Results: SMI was detected by SPECT in 62% and by DE in 10% of the patients (p < 0.0001), whereas significant coronary stenosis at angiography was detected by SPECT in 26% and by DE in 5% of the patients (p < 0.02). Independent predictive factors of significant coronary stenosis were male gender (p < 0.03) and peripheral arterial disease (p < 0.007). Nonfatal acute coronary syndrome occurred during follow-up in 2 patients (2%). Subsequent revascularization procedure was needed in 9 patients. Baseline patients' characteristics, as well as SMI, were not predictive of cardiac event during follow up.

Conclusion: SPECT seems more accurate than DE to detect significant coronary stenosis in high risk asymptomatic diabetic patients. In this population, aggressive treatment of SMI with systematic revascularization combined with intensive care of risk factors is associated with a favorable long-term prognosis, similar in diabetic patients with and without initial SMI.