New generation drug eluting stents show lower efficacy than contemporary BMS, study shows

New generation drug eluting stents (new DES) did not outshine contemporary bare metal stents (BMS) as they were expected to, in a surprise finding of the largest randomized stent trial to date.

The Norwegian Coronary Stent Trial (NorStent), presented at ESC Congress 2016, and published simultaneously in the New England Journal of Medicine, "demonstrates that the efficacy of new DES versus contemporary BMS is lower than expected," noted Kaare Harald Bonaa, MD, PhD, in a Hot Line session here.

"Patients treated with DES do not live longer and they do not live better than patients treated with BMS."

"Although ESC guidelines recommend new DES over BMS as default for coronary revascularization, this recommendation may need to be modified in light of the NorStent findings," he added. "Both stent types may be recommended."

With 9,013 patients and more than 40,000 patient years of follow-up, NorStent is an all-comers study in a usual care setting "and therefore has the potential to yield outcomes of great relevance to clinical practice," added Prof Bonaa from University of Tromso - The Arctic University of Norway, and the Norwegian University of Science and Technology, Trondheim.

The multi-centre study included patients with stable angina pectoris (n=2636) or acute coronary syndromes (n=6377) who needed percutaneous coronary intervention.

Patients were randomized to receive either BMS or DES, with 83% of DES patients receiving everolimus-eluting stents and 12% receiving zotarolimus-eluting stents.

After 6 years of follow-up there was no significant difference between the DES and the BMS groups in  the primary outcome of total mortality or nonfatal myocardial infarction (cumulative rate of 16.9% in the DES group vs 17.4% in the BMS group; HR 0.98), as well as secondary outcomes of unstable angina, or quality of life.

"As expected, the need for repeat revascularization was lowered by DES, but this effect was less than anticipated," noted Prof Bonaa.  "The 6 year cumulative rate of repeat revascularization was 16.5 % in the DES group vs. 19.8 % in the BMS group - an absolute risk reduction of 3.3 %. On the basis of this analysis, 30 patients would need to be treated with new DES in order to prevent one repeat revascularization, as compared with contemporary BMS. This figure is 2-fold higher than previously reported."