Effects of TCFA on stent neointimal coverage at 9 months after EXCEL drug-eluting stent implantation assessed by OCT

Background The aim of this study was to investigate the effects of thin-cap fibroatheromas (TCFAs) on stent neointimal coverage at the 9-month follow-up after EXCEL stent implantation assessed by optical coherence tomography (OCT). Methods A total of 93 patients with non-ST elevation acute coronary syndrome (NSTEACS) who underwent EXCEL stent implantation were prospectively enrolled in the study and divided into a TCFA group (n = 47) and a non-TCFA group (n = 46) according to whether EXCEL stents covered the TCFAs. A TCFA was defined as a plaque with lipid content in more than one quadrant and fibrous cap thickness measuring less than 65 mu m. The effect of TCFAs on stent neointimal coverage at the 9-month follow-up after stent implantation was evaluated by OCT. The primary study endpoints were the incidence of neointimal uncoverage and stent malapposition. Results At the 9-month follow-up, the minimal lumen diameter of the TCFA group tended to be smaller (2.8 +/- 0.8 vs. 2.1 +/- 0.8, p = 0.08) and the diameter of stenosis in the TCFA group tended to be larger (15.1 +/- 10.3% vs. 26.3 +/- 15.1%, p = 0.08) than those in the non-TCFA group. The mean intimal thickness of the TCFA group was significantly lower than that of the non-TCFA group (67.2 +/- 35.5 vs. 145.1 +/- 48.7, p < 0.001). The uncovered struts (10.1 +/- 9.7 vs. 4.8 +/- 4.3, p = 0.05) and malapposed struts (2.1 +/- 4.7 vs. 0.3 +/- 0.5, p = 0.003) in the TCFA group were more significant than those in the non-TCFA group. Multivariate analysis showed that TCFAs and lesion types were independent predictors of incomplete neointimal coverage (p < 0.05), and lesion types were independent predictors of stent malapposition (p < 0.05). Conclusion In patients with NSTEACS, TCFAs delayed endothelium coverage at 9 months after stent implantation, and TCFAs were independent predictors of incomplete neointimal coverage of the stent.