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.

Peristent tissue proliferation of multilink stents is dependent on preprocedural plaque area: a serial intravascular ultrasound analysis.

It is not known whether any factors are related to tissue proliferation within and surrounding stents in humans. The authors used serial intravascular ultrasound (IVUS) to evaluate the relationship between IVUS parameters and tissue proliferation within and surrounding Multilink stents. They were able to analyze preinterventional and postinterventional and follow-up IVUS studies in 33 native vessel lesions in 33 patients with stable angina pectoris. Quantitative coronary angiography and IVUS measurements were performed before and after intervention and at follow-up. IVUS imaging using an automatic transducer pullback device allowed follow-up analysis of the same lesion site. The vessel area at the lesion site increased from 17.1 +/- 4.5 mm2 after intervention to 18.5 +/- 5.9 mm2 at follow-up (p<0.01). The in-stent tissue growth (after intervention to follow-up) in-stent plaque area (PA) was 1.6 +/- 1.1 mm2, and the peristent tissue growth (after intervention to follow-up) peristent PA was 0.8 +/- 2.3 mm2. In multivariate analysis, the preprocedural PA at the lesion site was the best predictor of the peristent tissue growth, whereas no factors predicted the in-stent tissue growth. Risk factors, clinical characteristics, and quantitative coronary angiographic parameters showed no relation to the peristent tissue growth or the in-stent tissue growth. The peristent tissue growth was closely related to the preprocedural plaque size, while the factors that affect the in-stent tissue growth were not identified.