When to use bare-metal stents, when to use drug-eluting stents

Sep 5 2006

World Congress of Cardiology Report - Drug-eluting stents (DES) are more effective than bare-metal stents (BMS) in reducing restenosis and in repeat interventions after percutaneous coronary interventions (PCI).

However, late stent thromboses after DES implantation and higher costs have stimulated a new debate about whether all patients should receive DES. In an attempt to answer some questions, we used our "real-world" experience to define patient subgroups by comparing those with a very high clinical benefit from DES vs BMS use, to those with no benefit or only minimal benefit from the treatment.

In the prospective, randomised BASKET-Trial, all patients treated by PCI/stenting between May 2003 and May 2004 in the UniversityHospital of Basel, Switzerland, were included and randomised to receive Cypher, Taxus or Vision stents. Endpoints of the present analysis were cardiac death and myocardial infarction (Death/MI) up to 18 months after the procedure as well as occurrence of non-infarct related target vessel revascularization (TVR) and major cardiac adverse events (MACE). Based on multivariate event prediction analyses and tests for interaction with the different stent types, patient subgroups with high vs low clinical benefit from DES were identified.

Overall, event rates were low in all groups. Eighteen months rates of Death/MI was 8.4% for DES and 7.5% for BMS (p=0.63). There was, however, a significantly higher rate of non-infarct related TVR after BMS: 11.6% vs 7.5% after DES (p=0.05). This resulted in similar overall MACE rates after 18 months: 15.8% vs 18.9%, DES vs BMS respectively (p=0.26).

There were significant interactions between stent type and patient or lesion characteristics predicting events. Overall, only bypass graft interventions and the use of at least one small stent < 3.0mm showed significant interactions between stent type and two of the three main events (i.e. not-infarct related TVR , death/ MI and MACE, respectively). Therefore, we analyzed outcomes in patients with versus without these two characteristics. There were 268 patients (32%) treated with small stents or for bypass graft disease and 558 patients (68%) treated for large native vessels. Kaplan-Meier survival curves show the highly significant benefit of patients with small vessel/stent or bypass graft PCI from DES use not only with regard to MACE. In contrast, for all the other patients there was no benefit of DES compared to BMS, despite the significantly higher DES-strategy costs.

In the present long-term analysis of BASKET, only patients with small vessels/stents <3mm or bypass grafts treated showed a significant benefit from DES use regarding reduction of death, myocardial infarction and TVR. Patients with stenting of larger native vessels have no significant benefit and possibly even a small late harm.

Based on evidence from this long-term follow-up from BASKET, DES may be restricted to small vessels/stents <3mm and to bypass grafts for optimal cost-effectiveness and long-term benefit. These findings challenge the notion that today every patient should receive DES irrespective of baseline characteristics.