The Limited Usefulness of the Treadmill Test or a Risk-guided Approach in Screening for Asymptomatic Coronary Heart Disease in Japanese Patients with Type 2 Diabetes

OBJECTIVE: We prospectively investigated the efficacy of the screening methods for asymptomatic coronary heart disease (CHD) in Japanese patients with type 2 diabetes using the treadmill tolerance test (TTT) as a first-line test or the American Diabetes Association (ADA) guidelines. METHODS: The subjects included consecutive inpatients with type 2 diabetes (n=331) assessed with both electrocardiogram (ECG) at rest and TTT. Subjects with abnormal TTT findings were evaluated using stress myocardial perfusion scintigraphy (MPS). RESULTS: A total of 60 out of 69 subjects with positive TTT findings underwent MPS, among whom a total of 22 subjects (6.6% of the total number of subjects) had positive MPS results. Among those with positive MPS results, a total of 14 subjects underwent coronary angiography, eight of whom were determined to have significant coronary artery stenosis. The prevalence rates of hypertension and micro/macroalbuminuria were significantly higher in the MPS-positive group (77.3% and 54.5%, respectively) than in the TTT-negative group (44.7% and 27.1%, respectively). Among the subjects with positive MPS results, 68.2% met the 1998 ADA criteria. CONCLUSION: Neither the TTT as a first-line test nor the ADA guidelines are sufficiently adequate screening methods to detect asymptomatic CHD in Japanese subjects with type 2 diabetes. Conducting routine screening for asymptomatic CHD in Japanese patients with type 2 diabetes may therefore not be very useful.