Abstract 4144554: Revascularization of Patients with Low-Density Non-Calcified Plaque was Associated with Lower Occurrence of Acute Coronary Syndrome
Authors: Malkasian Shant , Hubbard Logan , Nurmohamed Nick , Chang Hyuk-Jae , Choi Andrew , Marques Hugo , Van Rosendael Alexander , Chow Benjamin , Andreini Daniele , Conte Edoardo , Maffei Erica , Plank Fabian , Pontone Gianluca , Feuchtner Gudrun , Samady Habib , Park Hyung-Bok , Danad Ibrahim , Cho Iksung , Bax Jeroen , Lee Ji Hyun , Baskaran Lohendran , Hadamitzky Martin , Budoff Matthew , Stone Peter , Heo Ran , Cury Ricardo , Lee Sang-Eun , Al'Aref Subhi , Stuijfzand Wijnand , lu yao , Kim Yong-Jin , Cademartiri Filippo , Virmani Renu , Narula Jagat , Rizvi Asim , Chinnaiyan Kavitha , Villines Todd , Leipsic Jonathon , Shaw Leslee , Molloi Sabee 
Published: November 2024

INTRODUCTION:
Coronary CT angiography (CCTA) is a powerful noninvasive tool for identifying high-risk plaque, such as low-density non-calcified plaque (LD-NCP). Though, the optimal treatment of patients with LD-NCP remains unclear. This study explored the association of revascularization in the setting of LD-NCP with the occurrence of acute coronary syndrome (ACS).

Methods:
This was a post-hoc analysis of the ICONIC study. A subset of 234 patients that underwent CCTA with subsequent ACS were matched to 234 control patients who also underwent CCTA but did not have ACS during follow-up. Patients were also followed for occurrence of revascularization, either coronary artery bypass graft or percutaneous coronary intervention. Atherosclerosis imaging-enabled quantitative CT (AI-QCT) was used to measure diameter stenosis, and LD-NCP, non-calcified plaque, and calcified plaque volumes from each CCTA. LD-NCP was defined as plaque with -190 to 30 Hounsfield Units. Patients were stratified based on the presence of LD-NCP. Subgroup analysis was conducted to compare the occurrence of ACS with the rate of revascularization. Kaplan-Meier survival curves and extended Cox regression analysis were used to evaluate the effect size of revascularization and LD-NCP on occurrence of ACS.

Results:
AI-QCT was completed in 448/468 subjects (follow-up time [MEAN±SD] 2.44±2.48 years). The median of LD-NCP was 1.2 mm
3
for patients with >0 mm
3
LD-NCP. There were 85 patients with LD-NCP >1.2 mm
3
and 363 patients with LD-NCP ≤1.2 mm
3
. In patients with LD-NCP >1.2 mm
3
, the rate of revascularization in patients with and without ACS was 3/52 (5.8%) versus 14/33 (42.4%) (p<0.001). In patients with LD-NCP ≤1.2 mm
3
, the rate of revascularization in patients with and without ACS was 36/170 (21.2%) versus 39/193 (20.2%) (p=0.897). In comparison to patients without revascularization and LD-NCP ≤1.2 mm
3
, patients with LD-NCP >1.2 mm
3
and revascularization were less likely to have ACS during follow-up (adjusted HR: 0.20 [0.07, 0.61]; p=0.005). Additionally, patients with LD-NCP >1.2 mm
3
who did not undergo revascularization were more likely to have ACS (adjusted HR: 1.47 [1.03, 2.12]; p=0.036). Hazard ratios were adjusted for diameter stenosis, and non-calcified and calcified plaque volume. Time-dependent coefficients were included for diameter stenosis.

Conclusion:
Revascularization of patients with LD-NCP >1.2 mm
3
identified on CCTA with AI-QCT was associated with less risk for ACS.