CRT 2021: Polymer-free amphilimus-eluting stent non-inferior to zotarolimus-eluting stent in PCI patients

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Three-year clinical outcomes from the Recre8 trial, a multicentre study comparing the safety and efficacy of the polymer-free Cre8 (Alvimedica) amphilimus-eluting stent to the Resolute Integrity (Medtronic) permanent-polymer zotarolimus-eluting stent, found that the Cre8 stent was non-inferior to Resolute Integrity at long-term follow-up.

The findings were presented by Michiel Voskuil, University Medical Centre Utrecht, Utrecht, The Netherlands, during a late-breaking trial session at the Cardiovascular Research Technologies meeting (CRT 21 Virtual, 13 February–24 April).

Voskuil told attendees of the virtual CRT meeting that rates of target lesion failure observed in patients receiving either of the two stents were similar, commenting that there was no major difference between the permanent polymer and the polymer-free stent design.

The investigator-initiated all-comers PCI trial, which was carried out in three Northern European centres, included patients with ischaemic heart disease who required PCI involving implantation of a drug-eluting stent. There were no exclusion criteria based upon clinical presentation or lesion characteristics.

The goal of the study was to establish non-inferiority of the polymer-free stent compared to the polymer stent with an endpoint of target lesion failure, which was a composite of cardiac death, target vessel myocardial infarction and target lesion revascularisation.

The study hypothesised that the Cre8 polymer-free amphilimus-eluting stent would be at least non-inferior to a permanent polymer zotarolimus-eluting stent in an unselected, all-comer patient population. Voskuil explained that the Cre8 stent works through the slow release of an amphilimus formulation via “abluminal reservoirs” from the thin strut cobalt-chromium stent.

The trial randomised 1,502 patients on a 1:1 basis to either of the stent platforms. Patients were stratified for their troponin status at baseline, to assess whether they had troponin-positive or troponin-negative disease, and whether they had a history of diabetes, and were randomised for implantation to either the Resolute Integrity or Cre8 stent. Troponin negative patients received one month of dual antiplatelet therapy (DAPT) post PCI, while the troponin positive patients that received one year of DAPT according to guidelines, Voskuil explained.

Detailing the study population, Voskuil noted that 20.4% of patients presented with diabetes mellitus, 19.9% with previous myocardial infarction, 47.5% presented with acute coronary syndrome (ACS), 58.6% with complex lesion anatomy, and 43.7% with multivessel disease.

Results after one-year of follow-up, previously published in Circulation, showed the non-inferiority of the two platforms both on the composite endpoints, as well as cardiac death, target vessel myocardial infarction and target lesion revascularisation as separate endpoints, Voskuil commented.

The study team analysed patient sub-groups, such as those presenting with diabetes, to establish whether there may be an extra benefit of the polymer-free stent design, but Voskuil noted that “none of the sub-groups saw any statistical difference between both stent frames”.

Voskuil commented that they also assessed the “late catch-up phenomenon” following DAPT cessation. Target lesion revascularisation beyond this one-year follow-up post DAPT cessation showed similar rates between the polymer-free stent and the permanent polymer stent, 2.1% and 3.1% respectively, Voskuil noted.

He added that there were some limitations to the study, including that physicians were not blinded to the allocation of treatment, and no randomisation was performed for DAPT duration, which Voskuil commented “would have been interesting, but would have needed to increase the amount of patients in follow-up dramatically”.

In his concluding remarks, Voskuil commented that the polymer-free amphilimus stent is clinically non-inferior to the permanent-polymer zotarolimus-eluting stent at long term follow-up, and that no late catch-up phenomenon could be shown in this patient cohort.

Discussion following Voskuil’s presentation centred on the non-inferiority design of the study, with speakers considering whether new iterations in stent technology are likely to lead to improvements in outcomes in patients.

On this topic, Don Cutlip, Beth Israel Deaconess Medical Centre, Harvard Medical School, Boston, USA, said: “We often forget that non-inferiority designs are very helpful for approval pathways, but we really look for some secondary benefit, which is really part of the non-inferiority planning process and I think with all of these trials we are not seeing that, to the extent that it might be even less expensive would be a secondary benefit.”

Turning to the results presented by Voskuil, Cutlip commented that since there were no indications of a major clinical benefit to patients, this supports “how good the second-generation stents are that we have currently”.

Voskuil was asked what further developments could be expected from the polymer-free amphilimus-eluting stent, to which he replied: “We are looking for sub-groups of patients that might benefit from this particular stent design and one of the patients that we are particularly interested in is diabetic patients. We are going to look into that to see if we get some clues for benefit in this specific patient group and if so maybe set up a new stent study for this group. However, currently we do not have any clues that we have this superiority for this specific stent.”


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