Ultrathin-Strut DES Outperform Second-Gen DES at 1 Year: Meta-analysis

The latest drug-eluting stents equipped with ultrathin struts are associated with a lower risk of target lesion failure by 1 year compared with second-generation DES, according to a new meta-analysis of randomized trial data.

“Compared to first-generation DES, contemporary second-generation DES have thinner struts and more biocompatible polymers, which reduce vascular injury and inflammation and promote faster endothelialization, decreasing neointimal proliferation and thrombogenicity,” write lead author Sripal Bangalore, MD (New York University School of Medicine, NY), and colleagues in their paper published online this week in Circulation.

But whether further design improvements will lead to better outcomes is not yet clear, they add, given that the potentials of bioresorbable-polymer and polymer-free DES are still unproven and first-generation bioresorbable scaffolds have largely disappointed.

Speaking with TCTMD, Bangalore said the news so far is good. “The second-generation stents were approved almost a decade ago, and since then there have been a number of stent iterations,” he told TCTMD. “We always used to see noninferior stents, so [the idea was] outcomes have plateaued. It was pleasantly surprising to see that if we go thinner, maybe that’s the way to go, because at least there is a signal toward improved outcome.”

For their meta-analysis, Bangalore et al looked at 10 randomized trials that compared newer-generation DES with strut thickness < 70 µm and second-generation DES with thicker struts in a total of 11,658 patients. Devices included the sirolimus-eluting Orsiro (Biotronik), MiStent (Micell), and BioMime (Meril) stents as well as the Xience (Abbott), Resolute Integrity (Medtronic), and Nobori (Terumo) DES. In the thinner group, struts ranged from 60 to 65 µm, while struts were between 81 and 120 µm in the thicker group.

Target lesion failure, the primary endpoint consisting of CV death, target-vessel MI, or ischemia-driven TLR, was less common at 1 year for the thinner-strut DES versus their predecessors (RR 0.84; 95% CI 0.72-0.99), a difference driven by lower risk of MI with the newer stents (RR 0.80; 95% CI 0.65-0.99). There also was a nonsignificant trend toward less stent thrombosis (RR 0.72; 95% CI 0.51-1.01).

“Of note, there was no difference in TLR between the stents,” the researchers say.

It’s possible that thinner struts may offer less radial force than thicker struts, they concede, adding, however, that angiographic outcomes from the various trials have reassuringly showed no disadvantage in terms of late lumen loss. “Despite this, ultrathin-strut DES may not be suitable for lesion subsets underrepresented in these trials such as heavily calcified lesions, ostial lesions, and chronic total occlusions,” the investigators caution.

Results were consistent across the ultrathin-strut DES and across the thicker-strut DES, suggesting a class effect. “It’s interesting to see that across three different stent platform types, we’re seeing this signal that there might be a benefit. So I think definitely there is promise, and we need more studies,” Bangalore said to TCTMD.

Note: Study co-author Gregg W. Stone, MD, is a faculty member of the Cardiovascular Research Foundation, the publisher of TCTMD.