A subgroup analysis of the BIO-RESORT three-year data showed significant differences in efficacy in favor of ultrathin strut Orsiro

Focusing on patients with small vessels, three-year outcomes of the BIO-RESORT randomized controlled trial (RCT) showed a significantly lower target lesion revascularization (TLR) rate and thus better efficacy of the Orsiro drug-eluting stent (DES) in comparison to the Resolute Integrity DES.

Prof. Clemens von Birgelen, Thoraxcentrum Twente, MST, Enschede, the Netherlands, presented the new subgroup data in a late-breaking clinical trials session at EuroPCR. In the large all-comers BIO-RESORT trial, 1,506 patients with small coronary vessels were treated with the Orsiro, Resolute Integrity or Synergy DES. The three-year results presented at EuroPCR 2019 and published in the Journal of the American Medical Association show the rate of target lesion failure (TLF) in favor of Orsiro 7.0% (Orsiro vs. Resolute Integrity p= 0.08), for Resolute Integrity 10.0% and for Synergy 9.5% (Synergy vs. Resolute Integrity p=0.72). In terms of cardiac death and myocardial infarction, the three stents showed similar results. However, patients treated with the ultrathin strut Orsiro experienced significantly fewer repeat target lesion revascularizations (TLR) than those treated with the thin strut Resolute Integrity (Orsiro 2.1% vs. Resolute Integrity 5.3%, p=0.009; Synergy 4.0%).

Divergence seemed more pronounced after the first year post index procedure, when dual antiplatelet therapy (DAPT) was stopped. This is supported in a TLR landmark analysis between one and three years, where the TLR rate with Orsiro was 1.0%, with Resolute Integrity 3.7% (p=0.006) and with Synergy 2.7%. Additionally, Orsiro showed a trend towards a lower rate of definite or probable stent thrombosis with a rate of 0.6% compared to 1.5% for Resolute Integrity (p=0.16) and 1.5% for Synergy.

“The results may be clinically relevant, as they suggest a relation between the use of ultrathin strut sirolimus-eluting stents and a lower repeat revascularization risk in all-comers patients with small target vessels,” explained principal investigator Prof. Clemens von Birgelen. “Due to a greater relative impact of stent strut size on lumen obstruction, the substantially thinner struts of these new-generation drug-eluting stents may be particularly advantageous in small vessels.”

In the large scale, multicenter BIO-RESORT trial, 42.9% of the full cohort of 3,514 patients undergoing percutaneous coronary intervention presented the need for small vessel treatment. While stenting of small coronary vessels is common, these patients are exposed to subsequent increased adverse cardiovascular event risks.

See- von Birgelen C, on behalf of BIO-RESORT investigators. "Three-year clinical outcome following treatment with thin, very thin or ultrathin strut DES in small coronary vessels in BIO-RESORT". Presented at: EuroPCR, May 21, 2019; Paris, France.