A randomized study comparing isotope and echocardiography stress testing in the screening of silent myocardial ischaemia in type 2 diabetic patients.

AIMS: This study aimed to compare the positive predictive value (PPV) of stress myocardial scintigraphy (SPECT) and of dobutamine echocardiography (DE) in the diagnosis of significant coronary artery stenosis (CAD) in asymptomatic type 2 diabetic patients, and to assess long-term clinical outcomes according to silent myocardial ischaemia (SMI) screening.

METHODS

A total of 204 asymptomatic type 2 diabetic patients at high cardiovascular (CV) risk were prospectively randomized to undergo either SPECT (n=104) or DE (n=100). Coronary angiography was proposed in cases of SMI, with revascularization of suitable lesions. Intensive treatment of CV risk factors was prescribed for all patients. Death and myocardial infarction (MI) were recorded during the 3-year follow-up.

RESULTS

Clinical characteristics were similar in the two testing groups. The prevalence of SMI and significant CAD were 13% and 4%, respectively, in the SPECT group vs 11% and 5%, respectively, in the DE group (not significant [NS]). The PPV for the detection of significant CAD was 29% for SPECT and 45% for DE (NS). Seven patients (3%) underwent initial revascularization. The 3-year rate of CV death and MI was 2.5%, and similar in both groups.

CONCLUSION

Rates of SMI and significant CAD in asymptomatic high-risk type 2 diabetic patients receiving intensive care of risk factors are low, and SPECT and DE are similar in the detection of SMI and CAD. Coronary revascularization and intensive CV risk-factor therapy are associated with a low rate of adverse CV events at 3 years, whichever stress test was used.