Association of insulin resistance and positive coronary artery remodeling and plaque burden in patients with acute coronary syndrome

Positive coronary remodeling (PR) and increased plaque burden (PB) are imaging markers of vulnerable coronary plaque. This study evaluated the association of insulin resistance (IR), assessed by the homeostasis model assessment of insulin resistance (HOMA-IR), with PR and PB in patients with acute coronary syndrome (ACS). We retrospectively included ACS patients who underwent IVUS-guided revascularization at a single center (December 2020 to December 2021). IR positivity was defined as HOMA-IR ≥ 2.5. IVUS was used to measure external elastic membrane (EEM) and lumen areas at the target lesion and reference segments. The remodeling index (RI) was calculated as target-lesion EEM area divided by the mean EEM area of proximal and distal reference segments. PR was defined as RI > 1.05, negative remodeling as RI < 0.95, and intermediate remodeling as 0.95–1.05. PB was calculated automatically by the IVUS system as (vessel area − lumen area)/vessel area. PB and remodeling analyses were lesion-level (111 lesions from 98 patients). Logistic regression for PR used patient-clustered robust standard errors. A total of 98 ACS patients (111 target lesions) were included. Compared with the HOMA-IR-negative group, the HOMA-IR-positive group had higher PB (70.91 ± 11.49% vs 66.03 ± 13.04%, p = 0.040) and a higher RI (1.02 ± 0.32 vs 0.88 ± 0.28, p = 0.018). The HOMA-IR-positive group also showed a higher proportion of PR (43.4% vs 15.5%, p = 0.002). In the revised cluster-adjusted multivariable model (adjusted for age, sex, HbA1c, BMI, eGFR, and oral anti-diabetic drug use), HOMA-IR positivity remained independently associated with PR (adjusted OR 3.59, 95% CI 1.08–11.92, p = 0.037). ROC analysis showed modest discrimination for HOMA-IR in identifying PR (AUC 0.656, 95% CI 0.542–0.771, p = 0.0074). The exploratory Youden-optimal cutoff was 2.44 (specificity 63.3%, sensitivity 71.9%). HOMA-IR-defined IR positivity was independently associated with PR and higher PB in this ACS IVUS cohort. However, HOMA-IR alone showed only modest discrimination for PR and should not be interpreted as a standalone clinical predictor.