Sex-specific features of optical coherence tomography detected plaque vulnerability related to clinical outcomes: insights from the CLIMA study

Purpose: To investigate the different impact of optical coherence tomography (OCT)-derived vulnerable plaque features on future adverse events (AEs) according to the biological sex. Methods: The prospective multicenter CLIMA study (ClinicalTrials.gov: NCT02883088) enrolled 1003 patients with OCT plaque analysis of non-treated coronary plaques located in the proximal left anterior descending artery. Sex-specific differences in plaque composition and vulnerable features were described. We investigated the incidence of AEs, including cardiac death, any myocardial infarction and target vessel revascularization at 1-year. Results: Among 1003 patients, 24.6% were women. Women were older and more frequently affected by chronic kidney disease. Dyslipidemia, prior MI and smoking habit were more common in men. At OCT analysis, women had shorter plaque length (p <0.001), ticker fibrous cap (p = 0.001), smaller maximum lipid arc (p =0.019), lower macrophage infiltration (p <0.001) and intra-plaque layered tissue (p =0.007). During follow-up, 65 AEs were registered. The presence of a thin fibrous cap and a large macrophage infiltration (>67 degrees) predicted AEs in both sexes. The presence of macrophages (HR 3.38, p =0.018) and a small minimum lumen area (HR 4.97, p =0.002) were associated with AEs in women but not in men, while a large lipid arc (> 180 degrees) was associated with AEs in men (HR 2.56, p =0.003) but not in women. Conclusion: This subanalysis of the CLIMA study investigated for the first-time sex-specific OCT features of plaque vulnerability associated with AEs. Local inflammation was associated with AEs in women and a large lipid arc was predictive in men. OCT may help develop sex-specific risk stratification strategies.