Impact of acute coronary syndrome on early in-stent neoatherosclerosis as shown by optical coherence tomography.

Background: Patients with acute coronary syndrome (ACS) have a higher risk of requiring target vessel revascularisation after percutaneous coronary intervention (PCI) than patients with stable angina. Neoatherosclerosis is a significant risk factor for very late stent thrombosis, and the presence of neoatherosclerosis is independently associated with major adverse cardiac events.

Aims: In this study, we used optical coherence tomography (OCT) to investigate the impact of ACS on neoatherosclerosis within 1 year after PCI.

Methods: We investigated 102 patients (122 lesions) who had undergone PCI using a second-generation drug-eluting stent (DES) from March 2017 to November 2020 and were followed up with OCT within 1 year. The patients were categorised into the ACS group or non-ACS group according to their clinical findings at the time of target lesion treatment. We used OCT to investigate the presence of neoatherosclerosis.

Results: The ACS group comprised 23 (22.5%) patients. There were no differences in the patients' clinical characteristics between the groups. The total stent length tended to be shorter in the ACS group than in the non-ACS group (24 mm vs 32 mm, respectively; p=0.09), but this difference was not statistically significant. The median duration from PCI was 290 days. Neoatherosclerosis was more frequent in ACS lesions (39% vs 4%; p<0.01), and implantation of a DES in ACS lesions was an independent predictor of neoatherosclerosis occurrence (odds ratio 9.70; p<0.01).

Conclusions: This observational study using OCT indicates that stenting for ACS lesions is associated with early in-stent neoatherosclerosis.