843-4 Reduction in late loss and restenosis in patients with small vessels treated with the slow rate-release, polymer-based paclitaxel-eluting stent: Results from TAXUS-IV

Basic science review: nitric oxide--releasing prosthetic materials

Prosthetic devices that come into contact with blood ultimately fail secondary to thrombus formation. This limits the utility of a variety of materials used to surgically treat cardiovascular disease, including vascular grafts and stents, as well as sensors and catheters placed within the circulatory system. Moreover, systemic anticoagulation that is used to prevent malfunction of these devices has potential for serious complications. It is known that nitric oxide (NO) produced via the endothelium imparts thromboresistant properties to native blood vessels. Thus, if NO were delivered locally to the site of the prosthetic material, it has the potential to halt thrombus formation while limiting life-threatening side effects. This review serves to examine the variety of NO-releasing materials that have been created with the two different classes of NO donors, the diazeniumdiolates and S-nitrosothiols, and the clinical applications of these prosthetics for potential future use.

Incidence, Timing, and Correlates of Stent Thrombosis With the Polymeric Paclitaxel Drug-Eluting Stent

OBJECTIVES

This study sought to study stent thrombosis with the paclitaxel-eluting Taxus stent.

BACKGROUND

The incidence and timing of stent thrombosis after drug-eluting stent placement compared with bare-metal stent implantation remain unsettled, with consequent uncertainty about risk stratification and long-term recommendations for antiplatelet medications.

METHODS

This study used a patient-based meta-analysis using the 4 principal TAXUS randomized trials (3,445 patients) with a follow-up duration of > or =1 year.

RESULTS

Cumulative stent thrombosis occurred in 1.28% +/- 0.31% in the Taxus group and 0.76% +/- 0.23% in the bare-metal stent group at 3 years (hazard ratio 1.51 [95% confidence interval 0.73 to 3.14], p = 0.26). Hazard ratios (per 100 patients per 6 months) were similar between the Taxus stent group (0.59 [95% confidence interval 0.22 to 0.95]) and the bare-metal stent group (0.64 [95% confidence interval 0.26 to 1.02]) through 6 months during the prescribed clopidogrel period. However, from 6 months to 3 years there were more stent thromboses in the Taxus group (hazard ratio 0.19 [95% confidence interval 0.06 to 0.32] vs. 0.02 [95% confidence interval 0.00 to 0.07], p = 0.049). Of 8 patients with Taxus-related thrombosis after 6 months, 0 were taking clopidogrel and 2 were not taking aspirin consistently. No Taxus-related stent thrombosis occurred after 2 years (922 patients thus far followed up for 3 years). Independent correlates of stent thrombosis were nonuse of clopidogrel, male gender, smoking, and possibly use of multiple nonoverlapping stents.

CONCLUSIONS

Approximately 0.8% of Taxus patients have stent thrombosis in the first 6 months after stent implantation, similar to bare-metal stents. However, a modest increase in risk is present with Taxus stents beyond 6 months, possibly because of inadequate antiplatelet drug therapy.