Predictors of target lesion revascularisation after drug-eluting stent implantation for calcified nodules: an optical coherence tomography study

Background: Evidence of prognostic factors for stent failure after drug-eluting stent implantation for cal-cified nodules (CNs) is limited.Aims: We aimed to clarify the prognostic risk factors associated with stent failure among patients who underwent drug-eluting stent implantation for CN lesions using optical coherence tomography (OCT).Methods: This retrospective, multicentre, observational study included 108 consecutive patients with CNs who underwent OCT-guided percutaneous coronary intervention (PCI). To evaluate the quality of CNs, we measured their signal intensity and analysed the degree of signal attenuation. All CN lesions were divided into dark or bright CNs according to the half width of signal attenuation, greater or lower than 332, respectively.Results: During the median follow-up period of 523 days, 25 patients (23.1%) experienced target lesion revascularisation (TLR). The 5-year cumulative incidence of TLR was 32.6%. Multivariable Cox regression analysis revealed that younger age, haemodialysis, eruptive CNs, dark CNs assessed by pre-PCI OCT, dis-rupted fibrous tissue protrusions, and irregular protrusions assessed by post-PCI OCT were independently associated with TLR. The prevalence of in-stent CNs (IS-CNs) observed at follow-up OCT was signi-ficantly higher in the TLR group than in the non-TLR group.Conclusions: Factors such as younger age, haemodialysis, eruptive CNs, dark CNs, disrupted fibrous tis-sue, or irregular protrusions were independently related to TLR in patients with CNs. The high prevalence of IS-CNs might indicate that the main cause of stent failure implanted in CN lesions could be the recur-rence of CN progression in the stented segment.