# Progression of Protruding Plaque in Acute Coronary Syndrome Diagnosed by Serial Optical Coherence Tomography

## TL;DR

This study shows that protruding plaque after stent implantation in heart attack patients can worsen over time, especially if cholesterol levels are not well controlled.

## Contribution

The study identifies a link between irregular plaque protrusion and atherogenic neointima progression in ACS patients, emphasizing the role of LDL control.

## Key findings

- Irregular protrusion lesions had a 17% risk of progressing to atherogenic neointima, while smooth protrusions did not.
- Lesions with atherogenic neointima showed significantly greater increases in plaque volume and stenosis.
- Higher LDL levels at follow-up were observed in the atherogenic neointima group despite similar baseline levels.

## Abstract

Background: Plaque protrusion after stent implantation is frequently observed in acute coronary syndrome (ACS) patients, yet studies on its long-term progression and clinical significance are limited. Methods: Seventy-eight ACS patients underwent optical coherence tomography (OCT)-guided PCI and follow-up OCT at 1 year. A total of 101 protruding lesions were classified into atherogenic neointima (AN) and non-AN groups based on OCT findings. Qualitative and quantitative assessments of protruding plaque, including irregularity and plaque intensity, were conducted. Results: AN developed in 17% of irregular protrusion (IP) lesions, whereas no smooth protrusion progressed to AN. Lesions in the AN group showed greater increases in protruding plaque volume (2.80 ± 0.46 mm2 vs. 0.67 ± 0.16 mm2, p < 0.001) and diameter stenosis (16.5% vs. 10.1%, p = 0.02). Follow-up LDL levels were higher in the AN group compared with the non-AN group (76.9 vs. 61.2 mg/dL, p = 0.02), despite similar baseline levels. Conclusions: Low-intensity IP after stent implantation in ACS patients carries a high risk of progression to AN, particularly under poor LDL control. Aggressive lipid-lowering therapy may mitigate this risk.