EGO-COMBO: Combo stent achieved neointimal regression, favorable clinical outcomes

WASHINGTON — Patients implanted with a dual-therapy stent achieved favorable clinical outcomes at 36 months and the stent was associated with neointimal regression at 24 months, according to findings presented at TCT 2014.

Stephen W.L. Lee, MD, of Queen Mary Hospital, University of Hong Kong, China, and colleagues conducted the EGO-COMBO prospective cohort study of 61 patients (mean age, 62.2 years; 77% men; 32.8% with diabetes) implanted with the Combo Dual Therapy Stent (OrbusNeich Medical).

The Combo stent combines abluminal sirolimus drug elution with an antibody surface that captures endothelial progenitor cells to the device, forming an endothelial layer to combat thrombosis and restenosis, according to the study background.

The researchers examined strut coverage at 2 months to 5 months, neointimal metrics verified via optical coherence tomography at 24 months and clinical outcomes at 36 months.

Strut coverage

Lee said during a presentation that 100% strut coverage was achieved at approximately 5 months. Therefore, he said, “We are quite certain that 5-month [dual antiplatelet therapy] will be long enough for this group of patients.”

When rapid strut coverage occurs, it could indicate optimal stent healing and predict better clinical outcomes and fewer late-stent failure events, Lee said. “In most DES[-treated patients], when the patient dies, we will discover uncovered struts,” he said.

Lee said that he and his colleagues documented that neointimal regression from 9 months to 24 months was achieved in the patients with the Combo stent, the first time that has been demonstrated in a DES.

In-stent percentage neointimal volume, which Lee said is “the most important surrogate marker for neointima assessment,” declined by 11.9% during that time (9-month median, 17.76; interquartile range [IQR], 12.21-21.22; 24-month median, 15.65; IQR, 11.17-19.35; P=.004).

Researchers also observed a 14.3% drop in strut-level neointimal thickness (9-month median, 0.14 mm; IQR, 0.08-0.21; 24-month median, 0.12 mm; IQR, 0.07-0.19; P<.001), a 13.4% decrease in neointimal cross section area at 1-mm sampling (9-month median, 1.34 mm²; IQR, 1.02-1.65; 24-month median, 1.16 mm²; IQR, 0.92-1.52; P=.001) and a 12.5% dip in neointimal volume (9-month median, 29.91 mm³; IQR, 22.13-43.22; 24-month median, 26.17 mm³; IQR, 19.64-35.81; P=.003).

Positive clinical outcomes

Lee said there were no cases of MI, neoatherosclerosis or definite or probable late stent thrombosis. At 36 months, researchers observed only one case (1.64%) of target lesion revascularization or target vessel failure; that patient died from vessel failure at 22 months after experiencing chest pain and not seeking medical advice, he said. Overall, MACE beyond 36 months was 3.3%, he added.

Lee said the results compare favorably with monotherapy DES, which have been associated with a continuous increase in restenosis and TLR over time. Although monotherapy DES achieves adequate short-term neointimal suppression, he said, “They all have a course of prolonged DAPT and they all have accelerated neoatherosclerosis and late stent failure, late loss catch-up and late stent thrombosis.” – by Erik Swain

For more information:

Lee SWL. Abstract 367. Presented at: TCT 2014; September 13-17, 2014; Washington, D.C.

Disclosure: The study was supported by OrbusNeich. Lee reports no relevant financial disclosures.