NORSTENT involved a similar scenario in a trial that addressed a totally different issue: Should patients with either stable or unstable coronary artery disease who are undergoing coronary stenting receive a drug-eluting stent (DES) or a bare metal stent (BMS)? The trial randomized 9,013 patients to receive either of the two stent types plus optimal medical therapy. The primary endpoint was the rate of all-cause death or nonfatal MI during 5 years of follow-up, and the results showed no statistically significant difference between the patients who received a DES and those who got a BMS (N Engl J Med. 2016 Aug 30. doi: 10.1056/NEJMoa1607991).
But for the secondary endpoint of repeat revascularizations performed during follow-up, the use of a DES cut the procedure rate by 3.3 percentage points, a 17% relative risk reduction that was statistically significant. The use of a DES also cut the stent thrombosis rate by 0.4 percentage points, a one-third relative drop in these events that was also statistically significant.
Mitchel L. Zoler/Frontline Medical News
Dr. Kaare H. Bønaa
In short, despite the neutral primary endpoint for the trial, the results showed that drug-eluting stents did what they were designed to do relative to bare metal stents: cut the rate of target lesion restenosis and the need for repeat revascularization. Several interventional cardiologists who heard the results at the meeting said that the findings would not change their practice and that they would continue to use the DES as their default device for percutaneous coronary interventions. Although “the long-term benefit of contemporary DES over BMS was less than expected,” said Kaare H. Bønaa, MD, lead investigator for the NORSTENT trial, the secondary benefit of significantly reduced repeat revascularization and the very modest price difference that now exists between drug-eluting stents and bare metal stents means that many interventionalists will continue to use a DES for most patients.
The message from Dr. Pocock and Dr. Stone, underscored by the DANISH and NORSTENT results, is that large and well-run randomized trials can yield important evidence to inform practice that transcends a simple black or white statistical assessment of the primary endpoint.
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