Reductions in restenosis rates with DES were better than expected in the SCAAR Registry.

Updated data from the Swedish Coronary Angiography and Angioplasty Registry, with 1- to 4-year follow-up on 34,530 patients, indicate no significant difference in death or MI between DES and bare-metal stents.

In addition, the adverse-event rate with either DES or bare-metal stents was higher for off-label use
compared with on-label use, said Stefan James, MD, of the Uppsala Clinical Research Center in Sweden
(Figure).

Reduced MI risk

In the first 6 months after stent implantation, there was a reduced relative risk of MI associated with
both off-label use of DES compared with bare-metal stents (RR = 0.72; 0.57-0.92) and with on-label use of DES (RR = 0.75; 0.57-0.98). There was no significant difference in adjusted rates of MI between the 2
types of stents after 6 months.

On-label use of DES was associated with a 60% relative reduction and a 4% absolute reduction in the risk of restenosis compared with bare-metal stent use; for off-label use of DES, these reductions in risk were 40% and 2.5%, respectively.

On-label use was defined as use within de novo lesions , 33 mm in length and between 2.5 mm and 3.5
mm in diameter for bare-metal stents and for the Cypher stent (Cordis, Johnson & Johnson); for the Taxus stent (Boston Scientific), on-label use was within a lesion , 32 mm in length and between 2.5 mm and 3.75 mm in diameter.

For this analysis, no more than 2 stents could be used in the same vessel. Patients had to be non-STEMI
and without a chronic total occlusion, graft lesions, or cardiogenic shock.

When death or MI rates were broken down by stable and unstable CAD vs. STEMI, there were no significant differences between on- or off-label use of DES vs. bare-metal stents.

“With STEMI there was a significant reduction in events with DES vs. BMS for the initial six months, which was compensated by a significantly increased risk of death and MI in the period of time after 6 months with DES,” James said.

No increased risk

Overall, the registry data indicate that off-label use of DES vs. baremetal stents is not associated with an
increased risk of adverse events, James said. Use of DES resulted in a lower reduction of clinically meaningful restenosis than had been expected.

Off-label use of DES compared with bare-metal stents still needs further evaluation in prospective randomized trials for various indications, James said.

The SCAAR Registry has records of all procedures performed in Sweden from 1989 through the present day. The registry lists over 13,000 patients who have undergone implantation with at least 1 DES, and over 20,000 patients with 1 or more bare-metal stents implanted between 2003 and 2005. Duringthe study period, there have been 3,850 MIs and 2,631 deaths.