Abstract Backgrounds Severely calcified lesions, including calcified nodule (CN), are associated with adverse events after percutaneous coronary intervention (PCI) with drug-eluting stent (DES). However, there are limited data about clinical outcome and morphological findings of de novo CN lesions after stent-less PCI with DCB. Purpose The purpose of the present study is to investigate associated factors of worse clinical outcome in patients with de novo CN lesions after stent-less PCI with DCB as assessed by optical coherence tomography (OCT), as well as morphological findings at follow-up period. Methods We enrolled 69 de novo coronary artery CN lesions in 59 patients who underwent PCI with DCB retrospectively. All lesions were treated without stent and underwent both pre- and post-PCI OCT. In this study, only eruptive CN was included, defined as lesion with fibrous cap disruption and luminal thrombus associated with eruptive, dense, calcific nodules. In addition, OCT medial dissection was defined as dissection extended into the media without disruption of the entire medial layer within DCB treated segment, as reported previously. Patients were divided into two groups; with or without target lesion failure (TLF), defined as composite of culprit lesion related cardiac death, myocardial infarction, and target lesion revascularization (TLR). Furthermore, sub-group of 16 lesions with serial OCT imaging (pre-, post-PCI at the index PCI and at follow-up or TLR) were assessed to examine morphological patterns of restenosis in CN lesions. Results Median age was 76 years, and 69.6% were male. All lesions showed OCT maximum calcium arc 90° and 95% of lesions were 180°. At the median follow-up period of 641 days, TLF events occurred in 11 lesions (15.9%) and associated with the absence of post-PCI OCT medial dissection (OCT medial dissection; TLR 45.5% vs non-TLR 89.7%, p=0.002). In sub-group analysis of 16 lesions with serial OCT imaging, TLR occurred in 8 lesions and we found 6 lesions were CN protrusion, one lesion was layered plaque at TLR and another one was underexpansion at the index PCI as a restenosis pattern. Moreover, compared with 8 non-TLR lesions, CN protrusion was significantly more frequent in TLR lesions at TLR or follow-up period (CN protrusion; TLR 75.0% vs. non-TLR 12.5%, p=0.041). Late lumen enlargement (LLE; defined as OCT minimum lumen area was larger at follow-up period than post-PCI at the index PCI) was found in 6 lesions (75.0%) without TLR and no LLE in non-TLR lesions (LLE; TLR 75.0% vs non-TLR 0%, p=0.007). Conclusions In lesions with DCB treatment for de novo CN coronary artery lesions, the absence of post-PCI OCT medial dissection was associated with TLF and CN protrusion was frequently observed at TLR on serial OCT imaging, whereas LLE was found in non-TLR lesions.
Matsuda et al. (Sat,) studied this question.