摘要： BACKGROUND: Using optical coherence tomography, we evaluated early follow-up findings of significant stent malapposition (SSM) in patients treated with second-generation drug-eluting stent. METHODS AND RESULTS: From the DETECT-OCT randomized trial (Determination of the Duration of the Dual Antiplatelet Therapy by the Degree of the Coverage of the Struts on Optical Coherence Tomography From the Randomized Comparison Between Everolimus- Versus Biolimus-Eluting Stent), a total of 386 patients (390 lesions) who underwent both postintervention and 3-month follow-up optical coherence tomography examinations were included for the present analysis. SSM was defined as a stent that had a strut with a maximal wall-to-strut distance of ≥200 μm. Postintervention, SSM was detected in 175 lesions (44.9%), including 117 lesions with a maximal wall-to-strut distance of ≥200 to <400 μm and 58 lesions with a maximal wall-to-strut distance of ≥400 μm. As the implanted stent diameter-to-reference vessel diameter ratio grew, the risk of postintervention SSM dropped (odds ratio, 0.587; 95% CI, 0.367–0.941; P=0.0398). The optimal value that best separated SSM from non-SSM postintervention was a stent diameter-to-reference vessel diameter ratio of 1.0. At 3 months follow-up, the frequency of SSM decreased from 44.9% to 33.6% (131 lesions; P=0.0001), mainly driven by the decrease in lesions with a maximal wall-to-strut distance of ≥200 to <400 μm. As the maximal wall-to-strut distance on postintervention optical coherence tomography was larger, the risk of 3-month SSM increased (odds ratio, 1.607; 95% CI, 1.131–2.286; P=0.0284). The optimal value that best separated SSM from non-SSM at 3 months follow-up was a maximal wall-to-strut distance postintervention of 230 μm. CONCLUSIONS: A spontaneous decrease in SSM was observed early in this qualified study with a large number of study patients treated with second-generation drug-eluting stent.