Optical coherence tomography analysis of the stent strut and prediction of resolved strut malapposition at 3 months after 2nd-generation drug-eluting stent implantation.

Abstract

Our objective was to clarify whether thrombogenic problems with stent struts are resolved at 3months after 2nd-generation drug-eluting stent implantation. Twenty-one patients with stable angina pectoris having 28 (22 zotarolimus-eluting, 6 everolimus-eluting) stents with optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) were evaluated. Stent strut coverage and malapposition were evaluated by OCT immediately after PCI and at 3-month follow-up. Acute strut malapposition was observed in 26 out of 28 analyzed stents (92.9%). At 3-month follow-up, 7 (26.9%) of those 26 stents with strut malapposition were completely resolved, and the mean percentages of uncovered struts and malapposed struts were 8.3 and 2.0% when analyzed by each individual stent. When analyzing a total of 30,060 struts, 807 struts (2.7%) demonstrated acute strut malapposition. Among these, 219 struts (27.1%) demonstrated persistent strut malapposition. On the basis of receiver-operating characteristic curve analysis, a strut-to-vessel (S-V) distance≤160µm on post-stenting OCT images was the corresponding cutoff point for resolved malapposed struts (sensitivity 78.1%, specificity 62.8%, area under the curve 0.758). The S-V distance of persistent malapposed struts on post-stenting OCT images was longer than that of resolved malapposed struts (235±112 vs. 176±93µm, p<0.01). At 3months after PCI, the prevalence rates of uncovered and malapposed struts were relatively low in 2nd-generation drug-eluting stent. Our results suggest that OCT-guide PCI with an S-V distance≤160µm may be recommended especially in patients with planed short-term DAPT.