Objectives To investigate the value of ATP stress ^99mTc-methoxyisobutylisonitrile (^99mTc-MIBI) gated myocardial perfusion imaging (G-MPI) for evaluating stent restenosis after coronary stent implantation.

Methods 66 patients with coronary stent implantation more than 3 months, accompanying a typical angina pectoris symptom. All patients underwent ATP stress ^99mTc-MIBI G-MPI and coronary angiography (CAG) within 1 month. Compared with CAG, we calculated the sensitivity, specificity and accuracy of ATP stress G-MPI in judging stent restenosis after coronary stent implantation.

Results 66 patients with 99 coronary arteries underwent stent implantation, 39(59%) patients, 45(45 %) coronary arteries appeared in-stent restenosis. The diagnostic sensitivity, specificity, accuracy, positive predictive value and negative predictive value of ATP stress G-MPI in judging stent restenosis for all patients were 85% (33/39), 89% (24/27), 86% (57/66), 92% (33/36) and 80% (24/30); for patients with myocardial infarction were 79% (15/19), 88% (14/16), 83% (29/35), 88% (15/17) and 78% (14/18), for patients with non-myocardial infarction were 90% (18/20), 91% (10/11), 90% (28/31), 95% (18/19) and 83% (10/12). The diagnostic value in the patients with non- myocardial infarction patients were higher than that in patients with non- myocardial infarction, but there no significant difference between two patients groups. The diagnostic sensitivity, specificity and accuracy of ATP stress G-MPI in judging stent restenosis for left anterior descending artery stent restenosis were 83% (20/24), 89% (16/18) and 86% (36/42) ,for left circumflex artery stent restenosis were 83% (5/6), 81% (13/16) and 82% (18/22), for right coronary artery stent restenosis were 80% (12/15), 75% (15/20) and 77% (27/35). The diagnostic sensitivity, specificity and accuracy for patients with 1 branch vessel lesion were 80% (8/10), 100% (5/5) and 87% (13/15), for patients with 2 -ranch vessel lesion were 91% (10/11), 82% (9/11) and 86% (19/22),for patients with 3 -ranch vessel lesion were 83% (15/18), 91% (10/11) and 86% (25/29).

Conclusions ATP stress ^99mTc-MIBI G-MPI has significant clinical value for diagnosing stent restenosis after coronary stent implantation.