A randomized control trial to assess optical coherence tomography parameters of the Xlimus drug-eluting stent: the XLIMIT trial

Background: Third generation drug-eluting stents (DES) potentially offer better technical performance and reduced neointimal proliferation than previous generation DES. The XLIMIT non-inferiority trial evaluated the performance of the Xlimus (a novel sirolimus-eluting coronary stent system) in terms of endothelialization and tissue healing compared to the bioresorbable polymer Synergy DES.

Methods: A total of 177 patients undergoing percutaneous coronary intervention (PCI) were randomized in a 2:1 ratio (2 Xlimus: 1 Synergy). The primary endpoints, defined as the in-stent neointimal volume weighted by the sum of the lengths of the implanted stent (ISNV) and the in-stent neointimal percent volume obstruction (%VO) were evaluated at 6-9 months by means of optical coherence tomography (OCT). Additional OCT parameters as well as clinical endpoints were also collected.

Results: Most of the patients were males (77.4%), and the mean age was 64 years. One third of the population had stable angina/silent ischemia. A total of 300 stents (237 lesions) were analyzed: 198 (152 lesions) were in the Xlimus group, and 102 (85 lesions) in the Synergy group. The ISNV in the Xlimus group was 30.7 ± 24.5 mm³ while in the Synergy group it was 26.5 ± 26.7 mm³: the difference between the two means was 0.08 (-0, 04-0, 45), p = 0.018, thus meeting the non-inferiority hypothesis. The %VO was 16.3% ± 10.4% and 13.3% ± 10.8% in the Xlimus and Synergy groups, respectively: the difference between the two means was 3.0 (-0, 06-4, 2), (p = 0.01), thus meeting the non-inferiority hypothesis. No difference was found with respect to the secondary OCT endpoints as well as for clinical endpoints.

Conclusions: The study results confirm that the biological interaction of the Xlimus and Synergy DES with the coronary artery is comparable, and that translates in very reassuring OCT parameters at follow-up: as such, the Xlimus is non-inferior to the Synergy.

Clinical trial registration: ClinicalTrials.gov, identifier (NCT03745053).