SORT-OUT VI: Permanent Polymer ZES Noninferior to Biodegradable BES in All-Comers Study

San Francisco, CA—A permanent polymer zotarolimus-eluting stent (ZES) and a biodegradable biolimus-eluting stent (BES) are both associated with low rates of MACE after PCI, and the ZES is noninferior, according to an all-comers study presented Tuesday in a late breaking clinical trials session.

For SORT-OUT VI, investigators led by Bent Raungaard, MD, of Aarhus University Hospital, Denmark, randomized 2,999 Scandinavian patients with chronic stable CAD or ACS and at least one coronary lesion of ≥50% diameter stenosis in a vessel with a reference diameter of 2.25 to 4 mm to PCI with the Resolute Integrity ZES (Medtronic; n=1,502) or the BioMatrix Flex BES (Biosensors; n=1,497). Approximately half of the patients in each group underwent PCI for stable angina and half for ACS.

After 12 months, the proportion of patients with MACE (a composite of cardiac death, MI and TLR) was similarly low in both stent groups (see Figure).

Additionally, there were no differences between stent groups in individual components of MACE, as well as TVR, definite stent thrombosis and definite/probable stent thrombosis.

Importance of long-term follow-up

Because complete degradation of the biodegradable polymers is expected at 9 months, follow-up will need to be continued past 1 year, Alexandra J. Lansky, MD, of Yale School of Medicine, New Haven, said in a press conference.

Ajay J. Kirtane, MD, SM, of Columbia University Medical Center, New York, N.Y., asked, “Are we doing so well with second-generation [DES] that we can’t tell the differences anymore?”

Lansky responded that “as the trials get larger and the devices get better, we’re seeing remarkable results at 1 year. When you look at the curves, they are superimposable. I haven’t seen any convincing evidence that a biodegradable polymer really makes that difference, and I think either there will be no difference or we will need 10,000 patients to show that.”

“These comparative stent trials are becoming increasingly difficult to do,” said Sunil V. Rao, MD, of the Duke University Medical Center, Durham, N.C., congratulating the researchers. “It does give us a lot of reassurance, and it makes clear that the current generation of drug-eluting stents that we’re using appear to be incredibly safe.”

Alice K. Jacobs, MD, of Boston University Medical Center, observed that there were more differences than anticipated between the randomized cohorts, but Raungaard assured attendees that the patients were randomized after angiography and any significant differences were due to a “play of chance.”

Mean age of trial participants was 66 years and three-quarters of patients were men. Baseline characteristics were well-balanced between the study arms, but more patients assigned to the BES arm had prior PCI (P=.03). Prior CABG trended higher in the ZES arm (P=.09). In each arm, 18% of patients were diabetic and almost one-third were current smokers (P=.97).

The number of lesions, the proportion of patients with more than one lesion and the proportion of patients treated with more than one stent were higher in the ZES arm. Also, the proportion of patients with complicated lesion types was higher in the ZES group, but not significantly.

Disclosures:

Raungaard reports no relevant conflicts of interest. The SORT-OUT VI trial was supported by unrestricted grants from Biosensors and Medtronic CardioVascular.