ROME -- Six years after treatment, there was no difference in outcome for patients who received second generation drug-eluting stents (DES) versus those who received bare metal stents (BMS), a finding that appears to confirm the safety of DES.
In the DES group 16.6% of patients reached primary endpoint, which was a composite of all-cause mortality and non-fatal myocardial infarction, versus 17.1% in the BMS group (HR 0.98, 95% CI 0.88-1.09, P=0.66).
But DES patients were less likely to need a repeat procedure -- the 6-year repeat revascularization rate was 19.8% for BMS versus 16.5% (HR 0.76, 95% CI 0.69-0.85, P<0.001) for DES, said Kaare Harold Bønaa, MD, of in Trondheim, Norway, who reported the findings at the European Society of Cardiology annual meeting.
It is not surprising that repeat procedures would be more common in the BMS group -- it was concern about restenosis with BMS that led to the development of DES -- but Bønaa said that here, too, the outcome was not entirely as expected: the number needed to treat with DES to avoid one repeat revascularization was 30.
"This was double the NNT that had been reported in other, smaller studies," he said.
ESC spokesperson Keith Fox, MBBS, of University of Edinburgh told that he thought NORSTENT would be practice changing because it provided evidence that BMS is still a very viable option for patients.
The results from the 9,013-patient NORSTENT trial were also simultaneously published in the New England Journal of Medicine.
"NORSTENT was the largest stent trial ever conducted," Bønaa said, noting that the study was investigator initiated with no industry support.
He said the study was undertaken because current ESC guidelines recommend DES as the preferred stent based on what he said was minimal evidence that DES had a superior safety and efficacy profile.
"On page 17 in guidelines it states that compared with BMS, DES improved safety including death, myocardial infarction and revascularization," he said.
Bønaa and his colleagues enrolled patients at eight centers in Norway from 2008 through 2011. Patients were then followed for a median of 5 years.
In addition to measuring hard endpoints, the investigators also assessed quality of life issues. "We measured physical limitations, frequency of angina, and overall quality of life and there was no difference," Bønaa said, illustrating his point with graphs showing no separation between the DES and BMS patients on any of those measures.
, of Brigham and Women's Hospital in Boston, had a decidedly different take on the findings. He told "These are really great, reassuring data about DES."
The study "was powered to see if there was an effect on hard events -- if they would increase or decrease with a DES," said Bhatt, who was not involved in the study. He interpreted the finding that there was no difference in the primary endpoint as prima facie evidence that DES should be the stent of choice for most procedures.
Bhatt also pointed to stent thrombosis to support his position, and by that measure DES was again superior: the rate of definite stent thrombosis was 0.8% versus 1.20%, which was significant but barely (P=0.0498).
The patients were evenly randomized to DES with either zotarolimus- or everolimus-eluting second generation devices (n=4,504) and BMS (n=4509). Seventy-five percent of the patients were men and the average age was 62.
Although NORSTENT confirmed safety and efficacy for the second-generation stents, the results also are reassuring for BMS, a point emphasized by , of the University of Michigan Medical Center in Ann Arbor.
In an accompanying editorial, Bates concluded that "the use of bare-metal stents remains an important option for PCI in some patients, including those with a large vessel diameter in whom restenosis rates are low, those who cannot complete the longer duration of dual-antiplatelet therapy recommended for drug-eluting stents because of noncompliance or need for noncardiac surgery, those who cannot pay for drug-eluting stents or a longer duration of dual-antiplatelet therapy because of increased cost, and those at increased risk for bleeding (e.g., patients with recent bleeding or a need for concomitant anticoagulation therapy)."
"The results of this important trial should increase confidence in choosing to implant bare-metal stents in selected patients if clinical indications favor that decision and should support guideline recommendations endorsing that option," he noted.
Disclosures
The trial was funded by the Norwegian Research Council.
Primary Source
New England Journal of Medicine
Bønaa KH, et al "Drug-eluting or bare-metal stents for coronary artery disease" N Engl J Med 2016; DOI:1 0.1056/NEJMoa1607991.
Secondary Source
European Society of Cardiology
Bates ER "Balancing the evidence base on coronary stents" N Engl J Med 2016; DOI: 10.1056/NEJMe1610485.