Impact of drug release kinetics on vascular response to different zotarolimus-eluting stents implanted in patients with long coronary stenoses: the LongOCT study (Optical Coherence Tomography in Long Lesions).

Objectives: We assessed the in vivo vascular response to a new generation of zotarolimus-eluting stents (ZES) with prolonged drug release (Resolute ZES-SR, Medtronic Vascular, Santa Rosa, California) compared with ZES with faster kinetics (Endeavor ZES-FR, Medtronic Vascular) by optical coherence tomography.

Background: Local drug release kinetics has been implicated with antirestenosis efficacy of drug-eluting stents. However, the impact of different release kinetics on vascular response of diseased human coronary arteries remains to be investigated.

Methods: The study population consisted of 43 patients with long lesions in native coronary vessels treated with multiple overlapping ZES. Twenty-one patients treated with ZES-SR were compared with 22 patients treated with ZES-FR from the ODESSA (Optical coherence tomography for DES SAfety) study. The primary endpoint was in-stent neointimal hyperplasia as assessed by optical coherence tomography at 6-month follow-up. Coprimary endpoints were the percentage of uncovered and malapposed struts.

Results: Strut-level median neointimal thickness was 0.11 mm (interquartile range [IQR]: 0.07 to 0.15 mm) in ZES-SR and 0.31 mm (IQR: 0.27 to 0.42 mm) in ZES-FR, respectively (p < 0.001). The 6-month rate of uncovered struts per patient was 7.38% (IQR: 3.06% to 12.72%) in ZES-SR and 0.00% (IQR: 0.00% to 0.00%) in ZES-FR (p < 0.001); rate of malapposed and uncovered struts was 1.47% (IQR: 0.32% to 4.23%) in ZES-SR and 0.00% (IQR: 0.00% to 0.00%) in ZES-FR (p < 0.001).

Conclusions: This study demonstrated the impact of different release kinetics on human in vivo vascular response to ZES implantation. The new generation of ZES-SR compared with ZES-FR had better suppression of the neointimal response but higher proportion of uncovered and malapposed struts at 6-month optical coherence tomography follow-up. (Optical Coherence Tomography in Long Lesions [LongOCT]; NCT01133925).