NORSTENT: Do Modern-day Bare-Metal Stents Stand Up to Drug-Eluting Stents?

ROME, Italy—The largest randomized stent trial in history has found no difference in the primary endpoint of death/nonfatal spontaneous MI between modern-day bare-metal stents and drug-eluting stents at 5 years in patients with stable or unstable coronary artery disease. As expected, however, the NORSTENT investigators did see a difference in repeat revascularization rates between groups.

The response to the results appears to be “business as usual,” with most cardiologists pointing out that stents have never been shown to reduce mortality—that their raison d’être lies in preventing reinterventions. And as such, these findings are unsurprising and, most say, won’t change their practice.

Still, as Kaare Harald Bønaa, MD (St. Olav’s University Hospital, Trondheim, Norway), noted in his presentation, current European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines for myocardial revascularization “state that ‘compared with bare-metal stents and early-generation DES, new-generation DES have also improved safety outcomes including death, myocardial infarction, and stent thrombosis.’ However, if we look at the evidence in favor of newer DES over BMS, the evidence is not as strong as we thought,” he said. 

Bønaa presented the NORSTENT results at a hotline session this morning at the European Society of Cardiology Congress 2016. The study was published simultaneously in the New England Journal of Medicine. 

Largest Randomized Stent Study

Fully funded by not-for-profit agencies, NORSTENT randomized 9013 patients with stable or unstable coronary artery disease to PCI with either a contemporary DES or a contemporary BMS. Of note, 95% of the stents used in the DES arm were everolimus- or zotarolimus-eluting stents. Bare metal stents used in the study were primarily the Driver, Integrity, Liberté, or Multi-Link Vision. More than two-thirds of patients in the study had ACS, and DAPT was used for at least 9 months in both trial arms.

After 6 years of follow-up, the primary endpoint had occurred in 16.6% of the DES-treated patients and 17.1% of the BMS group (P = 0.66). No differences were seen in either of the two components of the primary outcome—death or nonfatal, spontaneous MI. Quality of life, measured by the Seattle Angina Questionnaire (in translation), was no different between groups.

Importantly, but not surprisingly, the repeat revascularization rate was significantly higher in the BMS group—19.8% for BMS and 16.5% for DES (P < 0.001). Definite stent thrombosis trended higher in the BMS group at 1.2% versus 0.8% in the DES group (P = 0.0498). This latter point is particularly reassuring, given that NORSTENT started enrolling in September 2008 when the interventional community was recovering from the 2006 “DES firestorm” following reports of soaring stent thrombosis rates in the then still novel DES.

To the media, and in the hotline session, Bønaa observed that the restenosis rates for BMS were lower than expected. The number needed to treat with a DES to prevent one revascularization was 30, he said. This “is higher than what most had thought,” he said. “The figures I've seen before have been about 15 that we needed to treat with DES to prevent one revascularization. We found that that figure was at least twice as high.”

A Role in Certain Groups

In an accompanying editorial, Eric Bates, MD (University of Michigan Medical Center, Ann Arbor), points out that there remain certain populations in whom bare-metal stents remain an option, namely, people who can’t take DAPT long-term, can’t pay for a more expensive DES (or long-term DAPT), and those at high risk for bleeding.

“The results of this important trial should increase confidence in choosing to implant BMS in selected patients in clinical indications that favor that decision and should support guideline-recommendations endorsing that option,” he writes.

Discussing the results during the hotline session, however, Stefan James, MD, PhD (University of Uppsala, Sweden), was less inclined to meddle with the guidelines.

“New-generation stents should remain recommended over bare-metal stents due to better performance,” he said, citing the clear findings for reduction in revascularizations and stent thrombosis in NORSTENT. Moreover, he continued, “bare-metal stents should not be specifically recommended for patients with a higher risk of stent thrombosis or patients who do not tolerate DAPT.” 

Finally, James reminded the audience, “Stent selection is only one consideration in the treatment of patients with coronary artery disease. We also need to think of stent technology and other issues in the revascularization strategy, including timing of revascularization, antithrombotic strategy, and other medical therapies that may have proven survival benefit and need to be considered when treating patients with coronary disease.” 

Given a chance to respond to James, Bønaa said: “I don’t think I suggested that they should be recommended equally, but I do think this opens up the possibility for the use of BMS in certain circumstances.”

What Should Guidance Say?

Asked by TCTMD whether guidelines should be tweaked to take NORSTENT into consideration, Steen Dalby Kristensen, MD, DMSc (Cardiovascular. Research Centre, Aarhus University, Skejby, Denmark), hedged his bets. “I think it should be discussed,” he said. “But if you asked me what I would do in my daily practice, I will continue to use the newer-generation DES.”

While the difference in events between stent types was small in NORSTENT, Kristensen continued, ”the fact is, there were more revascularizations, [meaning] that the patient needs to go to hospital again to have a new procedure. For me, this is important. With the newer DES, there are some where you can use short-duration DAPT, so I think the newer-generation DES will be my choice.”

While stent prices may play a roll in some countries, Kristensen said, in many jurisdictions the costs are quite similar. The higher cost of DES is also offset by the cost of repeat hospitalizations and interventions with BMS. 

“To be frank, in our practice, we are not using bare-metal stents any more, and I will not go back home and change this now.”

Gregg Stone, MD (Columbia University Medical Center, New York, NY), was blunter still. “This study shows the drug-eluting stents do exactly what they were intended [to do], that is reduce target lesion revascularization by approximately 50%” he said. “Moreover, all of the trends in the safety endpoints, including death, MI and importantly stent thrombosis, were also going in the right direction with drug-eluting stents, although not statistically significant. The era for bare-metal stents has thankfully come and gone.

Andreas Baumbach, MD (University of Bristol, England), one of the hotline panelists, took a more equivocal position. “This is a headline grabbing presentation of course,” he said. “I think we’ll have to think about this trial for a good while.”