Myocardial perfusion scintigraphy to predict outcomes after coronary stenting.

The value of myocardial perfusion scintigraphy (MPS) in predicting the occurrence of restenosis or new coronary lesions after stent implantation is debatable. A total of 47 patients treated with successful bare stent implantation underwent stress gated SPECT MPS at three time-points: pre-procedure, early pos-procedure, and 6-month follow-up. Follow-up angiographic re-study was obtained at 6 months. Overall, 51.1% of patients had angiographic in-stent restenosis or a new lesion at follow-up. Pre-procedure MPS and early MPS scans did not differ between patients with or without restenosis/new lesions. At follow-up transient perfusion defects were observed in 26.1% of patients without restenosis/new lesions and in 75.0% of patients presenting with restenosis/new lesions (p<0.01) (sensitivity: 75.0%; especificity: 73.9%). When comparing early post procedure MPS to follow-up MPS, patients without restenosis/new lesions had no changes or a decrease in the number of segments with transient defects (median difference 0 [interquartile range -2 - 0]), while patients with restenosis/new lesions had an increase in transient defects (+2 [interquartile range 2 - 3.75]; p<0.01). Two multivariate factors independently predicted new lesion/restenosis: reference diameter < 2.9 mm (OR 6.50; p=0.05) and the difference in the number of segments with transient defects between early post procedure and follow-up MPS (OR 1.87; p<0.01). In conclusion, pre-procedure and early MPS did not predict complications after coronary stenting, while follow-up MPS was suboptimal in differentiating patients with or without new lesions/restenosis. However, the change in myocardial perfusion from early post-procedure to the follow-up scan was an important -prognostic factor to predict the incidence of new lesion/restenosis.