The OCT-ORION Study: A Randomized Optical Coherence Tomography Study Comparing Resolute Integrity to Biomatrix Drug-Eluting Stent on the Degree of Early Stent Healing and Late Lumen Loss.

BACKGROUND: Durable polymers used in drug-eluting stents are considered a potential cause of hypersensitivity inflammatory response adversely affecting stent healing. Using a sequential follow-up with optical coherence tomography, we compared the differences in healing profiles of 2 drug-eluting stents with a biodegradable or durable polymer. METHODS AND RESULTS: Sixty patients with multivessel disease were prospectively enrolled to receive both study stents, which were randomly assigned to 2 individual vessels, a Resolute Integrity zotarolimus-eluting stent with a durable BioLinx polymer and a BioMatrix NeoFlex Biolimus A9-eluting stent with a biodegradable polylactic acid polymer. Optical coherence tomography was performed at baseline, then in 5 randomly assigned monthly groups at 2 to 6 months, and at 9 months in all patients. The primary end point was the difference in optical coherence tomography strut coverage at 9 months. Key secondary end points included angiographic late lumen loss and composite major adverse cardiac events (cardiac death, myocardial infarction, target lesion revascularization, and definite or probable stent thrombosis) at 9 months. Resolute Integrity zotarolimus-eluting stent showed significantly better strut coverage than BioMatrix NeoFlex Biolimus A9-eluting stent at 2 to 6 months (P<0.001) and less variance of percent coverage at 9 months, 99.7% (interquartile range, 99.1-100) versus 99.6% (interquartile range, 96.8-99.9; difference, 0.10; 95% confidence interval, 0.00-1.05; P<0.001). No significant difference was observed in major adverse cardiac events or angiographic end points. CONCLUSIONS: Despite having a durable polymer, Resolute Integrity zotarolimus-eluting stent exhibited better strut coverage than BioMatrix NeoFlex Biolimus A9-eluting stent having a biodegradable polymer; both showed similar antiproliferative efficacy. This novel, longitudinal, sequential optical coherence tomography protocol using each patient as own control could achieve conclusive results in small sample size. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01742507.

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: The EGO-Combo Study.

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(3) (22.1 and 43.2) versus 26.2 mm(3) (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.