Battle of stents: Is skinnier better?

An ultrathin stent performed just as well as the conventional thin-strut stent in patients at high risk of bleeding in the first head-to-head COMPARE 60/80 trial, providing a new and effective drug-eluting stent (DES) option.

While the ultrathin-strut stent (Supraflex Cruz, SMT) was noninferior to the slightly-thicker-strut technology (Ultimaster, Terumo), it did not beat the thin-strut stent in terms of adverse clinical events (NACE) and other endpoints of the trial.

Both devices are biodegradable-polymer sirolimus-eluting stents. Supraflex Cruz stent has struts that are 60-μm thick whereas the Ultimaster device has a strut thickness of 80 μm.

Reflecting on the study, lead investigator Dr Pieter Smits from Maasstad Hospital, Rotterdam, the Netherlands, who presented the results at TCT 2023, said he was not disappointed at all by the absence of superiority in the trial as the goal was to show equivalence of the ultrathin stent to the thin-strut Ultimaster stent platform.

Need for safe, effective stents

“The need for safe and effective stents becomes more important in the changing landscape of PCI* with progressively shorter DAPT, particularly in patients at high bleeding risk,” he said. “In this context, Supraflex Cruz provides an excellent choice for physicians.”

The researchers compared the outcomes for both stents in 732 elderly patients (mean age 75 years, 73 percent men) at high bleeding risk who underwent PCI.  Nearly a third had diabetes. Approximately 70 percent were treated for chronic coronary syndromes. The mean duration of DAPT was 30 days.

At 12 months, the primary endpoint of NACE (a composite of cardiovascular death, MI, target vessel revascularization, stroke, and major bleeding) occurred in 15.4 percent of patients in the Supraflex Cruz group and 17.1 percent of patients in the Ultimaster group, demonstrating noninferiority of the ultrathin stent.

Importantly, the target lesion revascularization rate was lower with the ultrathin-strut stent (2.7 percent vs 5.3 percent; p=0.078). Most other cardiac endpoints were also numerically lower with the ultrathin-strut stent. There was no difference in the risk of definite/probable stent thrombosis.

“Ultrathin-strut stents, defined as measuring 70 μm or less, have been shown to be less thrombogenic and less traumatic to the vessel wall, and provide more rapid endothelialization, leading to less intimal hyperplasia compared with thicker stents,” said Smits.

Experts’ perspectives

Commenting on the findings, Dr Ajay Kirtane from the NewYork-Presbyterian/Columbia University Irving Medical Center in New York, New York, US, who moderated the session, said by taking on patients at high bleeding risk who were on shorter DAPT, investigators were able to reduce the number of patients needed to be enrolled to achieve noninferiority.

He added that any ultrathin device must be tested in heavily calcified lesions to determine if it is feasible to go any thinner for stents.  “In that setting, greater radial strength is needed. But in a trial like COMPARE 60/80, it was difficult to discern if there’s a downside to these ultrathin-strut devices.”

Dr Margaret McEntegart from the NewYork-Presbyterian/Columbia University Irving Medical Center meanwhile said she was surprised by the lack of imaging in a study that was trying to compare outcomes for stents with only a 20-μm difference in thickness. She said more widespread use of imaging, rather than scaling back stents, might be a better strategy to reduce the risk of adverse outcomes.

Smits, however, said the study reflects current practice in Europe where imaging is used in only 5–10 percent of cases. “In a setting where you don’t have the ability to use intravascular imaging in a high percentage of cases, I think the choice of stent becomes potentially more important.”