Evaluation of Early Healing Profile and Neointimal Transformation Over 24 Months Using Longitudinal Sequential Optical Coherence Tomography Assessments and 3-Year Clinical Results of the New Dual-Therapy Endothelial Progenitor Cell Capturing Sirolimus-Eluting Combo Stent

Monotherapy drug-eluting stents (DES) suppress neointimal proliferation and reduce the 1-year target lesion revascularization rate better than bare-metal stents but have other issues about safety and efficacy. Inadequate endothelial strut coverage causes stent thrombosis requiring stringent dual-antiplatelet therapy. Late catch-up with cumulative increase in the target lesion revascularization rate seems inevitable for most monotherapy DES. Accelerated Background—Current monotherapy drug-eluting stents are associated with impaired healing, neoatherosclerosis, and late stent thrombosis. The healing profile and neointimal transformation of the first dual-therapy endothelial progenitor cell– capturing sirolimus-eluting stent are unknown. Methods and Results—In this prospective, single-center study, 61 patients treated with the Combo stent had optical coherence tomography at baseline, early follow-up (4 monthly groups in a 1:2:2:1 ratio from 2 to 5 months), 9 months, and 24 months. Optical coherence tomography early strut coverage increased from 77.1% to 92.5% to 92.7% to 94.9% between 2 and 5 months. At 9 months, the major adverse cardiac event rate was 1.64%, and angiographic in-stent late loss was 0.24 mm (0.08–0.40). The 36-month major adverse cardiac event rate was 3.3%. From 9 to 24 months, neointimal regression was confirmed by optical coherence tomography: neointimal thickness (median [first quartile and third quartile]), 0.14 mm (0.08 and 0.21) versus 0.12 mm (0.07 and 0.19), P<0.001; neointimal volume, 29.9 mm (22.1 and 43.2) versus 26.2 mm (19.6 and 35.8), P=0.003; and percent neointimal volume, 17.8% (12.2 and 21.2) versus 15.7% (11.2 and 19.4), P=0.01. No definite or probable late stent thrombosis was recorded. Conclusions—With additional endothelial progenitor cell–capturing technology, the Combo stent exhibits a unique late neointimal regression (from 9 to 24 months) that has not been reported in any drug-eluting stents, translating into good 36-month clinical results with minimal restenosis and no late stent thrombosis. This is the first study testing the concept of using a longitudinal sequential optical coherence tomography protocol to continuously document early healing profile and late neointimal transformation, predicting long-term outcomes of a new novel stent platform. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifiers: NCT01274234, NCT01756807, and NCT02263313. (Circ Cardiovasc Interv. 2016;9:e003469. DOI: 10.1161/CIRCINTERVENTIONS.115.003469.)