Chronic total occlusion is associated with a higher incidence of malapposition and uncovered stent struts: OCT findings at 6 months following DES implantation

Objectives To compare stent coverage and malapposition in patients with chronic total occlusion (CTO) lesions and non-CTO lesions (including lipid-rich plaque [LRP] and non-lipid-rich plaque [non-LRP]) after drug-eluting stent (DES) implantation by optical coherence tomography (OCT). Background Different initial lesion characteristics may be related to heterogeneous vessel responses after DES implantation. However, the vessel response in patients with CTO and non-CTO lesions after stenting is unclear. Methods We retrospectively enrolled 64 patients with 68 target lesions. All of the patients underwent OCT imaging immediate after stenting and 6 months after stenting. LRP was defined as the plaque with lipid content in ≥2 quadrants. Non-LRP consisted of fibrous, fibrocalcific plaque, and lipid plaque with less than 2 quadrants lipid content. Results The malapposition (3.0%, 2.6% vs. 0.6%, P = 0.022), tissue protrusion (15.0% vs. 11.0% vs. 6.4%, P < 0.001), and intrastent thrombus (3.8% vs. 2.4% vs. 1.1%, P = 0.012) were more frequent in the CTO and LRP groups. At 6-month follow-up, malapposition (5.0% vs. 1.0% and 0.4%, P = 0.002) and cross sections with uncovered struts (23.4% vs. 8.2% and 6.6%, P < 0.001) were most frequently observed in the CTO group. Although the incidence of stent thrombosis was non-significantly higher in the CTO group than the other two groups, no events were observed in patients with CTO. Conclusions Patients with CTO lesions showed unfavorable responses to DES in the acute phase as well as at the 6-month follow-up, indicating the important pathological link between the original lesion morphology underneath the stents and heterogeneous artery healing. © 2017 Wiley Periodicals, Inc.