[TCT2007]No Benefit of Thienopyridines Beyond 1 Year in Analysis of TAXUS Data

Five-year follow-up from 3 trials: no event rate difference between bare-metal stents and DES.

There was no significant benefit from extended thienopyridine use in patients with DES or
bare-metal stents with up to 5 years’ follow-up, according to a retrospective analysis of pooled data from three clinical trials.

Gregg W. Stone, MD, chairman of the Cardiovascular Research Foundation, presented the analysis of combined data from 5-year results of the TAXUS II and TAXUS IV trials and 2-year results of the TAXUS V trial.

“The current analysis does not provide support for routinely extending thienopyridine treatment beyond 1 year in patients event-free at this time after either DES or bare metal stents in single de novo lesions in native coronary arteries,” Stone said.

The impetus for the landmark analysis, he said, was the conflicting results reached by researchers from Duke University and Milan, Italy. The two groups reached opposite conclusions concerning the risk of adverse events in patients receiving DES.

The trials included 2,171 patients who were free of death, MI, TVR or ARC-defined stent thrombosis at 1
year after PCI.

No differences seen

Patients were divided according to whether they received a bare-metal stent (n = 1,030) or a Taxus (Boston Scientific) stent (n= 1,141), and subdivided into those taking or not taking a thienopyridine at 1 year (56.6% of those with bare-metal stents and 54.7% of those with DES were not taking a thienopyridine).

No statistically significant benefits of thienopyridine use were seen among the 4 groups (patients receiving DES or bare-metal stents with or without thienopyridines) at 2 or 5 years in terms of all-cause
death; death or MI; stent thrombosis; or death, MI or stent thrombosis (P = NS for all).

Multivariate analysis was performed to compensate for baseline differences. No statistically significant differences were seen among the four groups.

Stone pointed out that stent thrombosis occurred in 12 patients with DES – 8 who were noncompliant with thienopyridines at 1 year and 4 who were compliant. This difference was not statistically significant (P = .43).

In those who were noncompliant with drug therapy, thrombosis occurred within at least 410 days and up to 1,334days after drug therapy was stopped. In the DES patients who were compliant with thienopyridine use at 1 year, 2 of the stent thromboses occurred while the patient was still taking the drugs.

There were some significant baseline differences between those taking and not taking a thienopyridine at 1 year, Stone said. In patients with DES, among those taking the drug there were more diabetic patients (29.4% vs. 19.9%, P = .0002). In addition, in both DES and bare-metal stent patients, lesion length was longer, number of stents was greater, and total stent length was greater in those taking a thienopyridine (P , .05 for all).

Some patients who were compliant with thienopyridine at 1 year were noncompliant by 5 years, and some who were noncompliant at 1 year had become compliant during the remaining follow-up. These differences were compensated for with multivariate analysis, Stone said.