Early detection of coronary heart disease in diabetic patients without symptoms of coronary artery disease: Implications for expanded use of myocardial perfusion imaging

Patients with type 2 diabetes are at a markedly increased risk of a myocardial infarction than their non-diabetic peers. These patients often do not develop the classic warning signs of myocardial ischaemia, such as chest pain. Rather, they can display atypical symptoms or present with an acute myocardial infarction as the first indication of the presence of coronary artery disease. Current risk factor management techniques, largely based on risk factor scoring, have failed to identify this clinically important sub-population of patients, and the early diagnosis of silent myocardial ischaemia in this population would greatly aid risk stratification and subsequent therapy. Myocardial perfusion scintigraphy (MPS), using single-photon emission computed tomography (SPECT), has emerged as a specific and sensitive technique for detection of coronary artery disease in type 2 diabetic patients who have yet to develop signs or symptoms of coronary artery disease. Such abnormalities are common in this population, and are significantly associated with an increased risk of myocardial infarction or death from ischaemic heart disease. The current evidence supports MPS with SPECT as the methodology of choice for identifying silent myocardial ischaemia possibly improving cardiovascular risk stratification. Appropriate use of this technique allows earlier identification of coronary artery disease in diabetic patients.