Usefulness of stress myocardial perfusion imaging for evaluating asymptomatic patients after coronary stent implantation.

BACKGROUND: Stent implantation in coronary angioplasty has reduced the rate of restenosis, but many patients still undergo follow-up coronary angiography (CAG). The present study was a multi-center retrospective analysis of the usefulness of stress single photon emission computed tomography (SPECT) compared with follow-up CAG in stent-implanted patients who remained asymptomatic during the follow-up period. METHODS AND RESULTS: The study group of 103 patients underwent both SPECT and CAG at 4-9 months after stent implantation. Restenosis occurred in 20 (19%) of 106 vessel territories, and a reversible perfusion defect was found in 32 (30%) territories. Sensitivity, specificity, positive and negative predictive values, and accuracy of SPECT were 65%, 78%, 41%, 91%, and 76%, respectively. The accuracy was lower in territories with a prior myocardial infarction (71%), in the left circumflex artery (58%), and in cases with three-vessel disease (63%). The negative predictive value was high, but 7 false negative cases included 4 cases with prior myocardial infarction, and 2 cases with reversible defects in other vessel territories. CONCLUSIONS: Stress SPECT imaging is a useful tool for following up patients with coronary stent implantation, and follow-up CAG could be omitted in patients with negative SPECT imaging, no prior myocardial infarction, one- or two-vessel disease, and sufficient stress loading.