Changes in ischaemia as assessed with single-photon emission computed tomography myocardial perfusion imaging in high-risk patients with diabetes without cardiac symptoms

AIMS: The study aims (i) to evaluate changes in myocardial ischaemia on single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) after 2 years in a cohort of high-risk patients with diabetes without cardiac symptoms or known coronary artery disease (CAD) and (ii) to assess the value of baseline computed tomography coronary angiography (CTA)-derived coronary atherosclerosis parameters to predict changes in myocardial ischaemia.

METHODS AND RESULTS: The population consisted of 100 high-risk patients with diabetes without cardiac symptoms referred for cardiovascular risk stratification. All patients underwent coronary artery calcium (CAC) scoring, CTA, and SPECT MPI. After 2 years of follow-up, SPECT MPI was repeated to evaluate potential progression of ischaemia.In total, 20% of patients presented with ischaemia at baseline. Of these 20 patients, 7 (35%) still had ischaemia at follow-up, whereas 13 (65%) showed resolution and 4 (20%) showed progression of ischaemia at follow-up. Of the 80 patients without ischaemia at baseline, 65 (81%) had a normal MPI at follow-up and 15 patients (19%) presented with new ischaemia. There were no significant differences in the CAC score or the extent, severity, and composition of CAD on CTA between patients with and without ischaemia at baseline. Similarly, no differences could be demonstrated between patients with and without ischaemia at follow-up or between patients with and without progression of ischaemia.

CONCLUSION: The rate of progression of ischaemia in high-risk patients with diabetes without cardiac symptoms is limited. Few patients presented with new ischaemia, whereas some patients showed resolution of ischaemia. Atherosclerosis parameters on CTA were not predictive of new-onset ischaemia or progression of ischaemia.