Near-infrared spectroscopy predicts events in men and women: Results from the Lipid Rich Plaque study

Abstract

Background: The Lipid Rich Plaque (LRP) study demonstrated that near-infrared spectroscopy imaging of non-obstructive lesions identified patients and segments at higher risk for subsequent non-culprit major adverse cardiac events (NC-MACE). Whether this is true for both men and women is not known. In this post hoc analysis of the LRP study, we sought to investigate whether the maximum 4-mm Lipid Core Burden Index (maxLCBI_4mm) was of similar predictive value in men and women for NC-MACE.

Methods: Patients with an evaluable maxLCBI_4mm were stratified on the basis of sex at birth. A Cox proportional-hazards model was used to assess the predictive value of maxLCBI_4mm on future NC-MACE at the patient and plaque levels. The primary endpoint was cumulative incidence of NC-MACE at 24 months.

Results: Among 1271 patients, 388 (30.5%) were women. Women were older and had a higher cardiovascular risk profile. Cumulative incidence of NC-MACE at 24 months was 10.3% for women and 7.6% for men (log-rank p = 0.11). When comparing maxLCBI_4mm > 400 to maxLCBI_4mm ≤ 400, the hazard ratio (HR) for future NC-MACE was not significantly different between sexes: 2.10 (95% confidence interval [CI]: 1.28-3.44; p = 0.003) for men and 2.24 (95% CI: 1.18-4.28; p = 0.014) for women (p = 0.87). At the plaque level, the HR comparing maxLCBI_4mm > 400 to maxLCBI_4mm ≤ 400 was 3.49 (95% CI: 1.60-7.60, p = 0.002) for men and 4.79 (95% CI: 2.02-11.38, p < 0.001) for women, which was not significantly different (p = 0.57).

Conclusions: The maxLCBI_4mm was of similar predictive value for NC-MACE within 24 months in men and women.

Keywords: Intravascular ultrasound; Lipid-rich plaque; Near-infrared spectroscopy; Non-culprit major adverse cardiac events; Sex.