Incidence and predictors of target vessel revascularization after sirolimus-eluting stent treatment for proximal left anterior descending artery stenoses among 2274 patients fromthe prospectivemulticenter German Cypher Stent Registry

Sirolimus eluting stent (Cypher) in patients with diabetes mellitus: results from the German Cypher Stent Registry

BACKGROUND

Patients with diabetes mellitus (DM) undergoing percutaneous coronary intervention (PCI) are at increased risk for adverse outcomes. The use of sirolimus eluting stents (SES) has been shown to improve outcomes in diabetic patients. Since results from randomized trials were derived from selected patients scientific scrutiny under real world conditions is necessary.

METHODS AND RESULTS

1,948 patients with DM and 4,707 patients without DM were included in the German Cypher Registry, a post-marketing survey of use of SES in Germany. In >99% of entry cases a structured clinical follow-up was completed. By angiographic criteria severity of coronary artery disease was higher in diabetic patients compared to non-diabetics. However, procedural success and in-hospital complication rates were comparable between DM- and non-DM-patients. 6 months MACE rate in the DM group was significantly higher than in the non-DM group (16.4% vs. 13.0%) but lower than expected from historical data with the use of bare metal stents (BMS).

CONCLUSION

The results with SES in diabetics are encouraging but DM remains a risk factor for poor outcome of PCI. No statement is justified whether the treatment of diabetics with SES is at least as safe as bypass surgery. This intriguing question has to be answered in a direct randomized head-to-head comparison with state of the art surgery.

In vitro evaluation of coronary stents and in-stent stenosis using a dynamic cardiac phantom and a 64-detector row CT scanner

INTRODUCTION

The aim of the study was to examine the ability of a 64-slice MDCT to detect in-stent stenoses in an ex vivo model of coronary stents.

METHODS

Five different stents (Liberté, Boston Scientific; Driver, Medtronic; Multi-Link Vision, Guidant; Taxus Express, Boston Scientific; Cypher, Cordis) were examined using a dynamic cardiac phantom. The stents were pulled over a vessel model that consists of a polymer tube with diameters of 3.0, 3.5, and 4.0 mm and four different degrees of stenoses (0%; 30%; 50%; 70-80%). This model was moved with a rate of 60 bpm to mimic cardiac motion. To assess the degree of artificial signal reduction (artificial reduction of attenuation (ARA)) by the different stents, attenuation values were measured in the vessel outside the stent, and in the non-stenotic vessel inside the stent. Furthermore the grade of stenosis was assessed by two clinical observers.

RESULTS

Highest ARA was found for the Cypher Stent (35 HU), whereas the Liberté Stent presented the lowest ARA (16 HU). Depending on the stent and the vessel diameter, up to 87.5% of the stenoses were correctly diagnosed. In the 3.0 and 3.5 mm vessels, a nonstenotic or low-grade stenotic vessel was diagnosed as intermediate or high-grade stenosis in 22.5%, whereas in the 4.0 mm vessels, this kind of overestimation did not occur. A 50% stenosis was diagnosed as a 30% stenosis in 30%. On the other hand, high-grade stenoses were underestimated in only 10%. On a four-point scale, the average deviation from the real grade of stenosis was 0.21 for the Liberté stent, 0.54 for the Taxus Express stent, 0.29 for Driver stent, 0.62 for the Multi-Link Vision stent, and 0.37 for the Cypher stent.

CONCLUSIONS

In a dynamic cardiac phantom model, high grade stenoses in vessels with a diameter of 4 mm could be reliably detected irrespective of the stent type used in this study. Vice versa, high grade stenoses (> or = 50%) could only be ruled out with certainty in vessels with a diameter of 4 mm. In smaller vessels, the ability to correctly diagnose high-grade stenoses was dependent on the type of stent and the imaging artifacts associated with it.