Underlying Plaque Type and Neoatherosclerosis After ST-Segment Elevation Myocardial Infarction　- Serial Optical Coherence Tomography Substudy of the CONNECT Trial

The relationship between underlying plaque type and the development of neoatherosclerosis remains uncertain.

This was a secondary analysis of the CONNECT trial, which randomized 239 patients with ST-elevation myocardial infarction (STEMI) to receive biodegradable polymer or durable polymer everolimus-eluting stents. Patients with serial optical coherence tomography (OCT) were included and post-procedural OCT frames that corresponded to segments showing neoatherosclerosis at the 3-year follow-up (NA-leading segments) were identified by manual frame matching. At the frame level, we compared post-procedural OCT findings in NALS to 2 comparators: non-NA-leading lesions (lesions without neoatherosclerosis); and non-NA-leading segments within NA-leading lesions. Of 144 lesions with serial OCT, neoatherosclerosis occurred in 17 (11.8%). In NA-leading segments, compared to non-NA-leading lesions and non-NA-leading segments within NA-leading lesions, the proportion of frames with lipid-rich plaque was higher (71% vs. 54% [odds ratio (OR) 2.72; 95% confidence interval (CI) 1.23-6.01] and 58% [OR 2.62; 95% CI 0.99-6.96], respectively). Similarly, the mean (±SD) in-stent atherothrombotic material area was larger in NA-leading segments (0.41±0.39 vs. 0.24±0.31 [geometric mean ratio (GMR) 2.00; 95% CI 1.21-3.29] and 0.16±0.16 mm²[GMR 2.33; 95% CI 1.26-4.31], respectively).

Underlying lipid-rich plaque and a higher burden of in-stent atherothrombotic material were associated with neoatherosclerosis at 3 years in STEMI patients, indicating that plaque composition at the time of DES implantation may critically influence neoatherosclerosis formation.