High-risk coronary plaque on coronary ct angiography predicts short-term cardiovascular events in cancer survivors with predominantly non-obstructive disease

Background Cancer survivors frequently develop cardiovascular events despite low rates of obstructive coronary disease. Coronary computed tomography angiography (CCTA) can identify high-risk plaque phenotype that may refine risk beyond stenosis severity. Purpose To assess whether high-risk plaque features on CCTA predict short-term cardiovascular events in cancer survivors. Methods We studied consecutive cancer survivors referred for clinically indicated CCTA between 2021–2025. High-risk plaque was defined by the presence of ≥1 high-risk feature (low attenuation plaque, positive remodelling, spotty calcification, or napkin-ring sign). Obstructive disease was defined as ≥50% stenosis. The primary outcome was a 12-month composite of acute coronary syndrome, revascularisation, or cardiovascular hospitalisation. Multivariable Cox regression adjusted for age, sex, diabetes, hypertension, dyslipidaemia, smoking, and coronary calcium category. Results Among 286 cancer survivors (mean age 54±11 years; 52% female), obstructive disease was present in 24 (8%). High-risk plaque features were identified in 47 (16%) and were more frequent in patients with prior chest radiotherapy (22% vs 13%). At 12 months, the composite outcome occurred in 20 patients (7.0%). Event rates were higher with high-risk plaque than without (14.9% vs 5.5%, p=0.01), while obstructive stenosis alone was not the dominant driver of events. High-risk plaque remained independently associated with outcomes after adjustment (adjusted hazard ratio 2.6, 95% CI 1.2–5.5). Notably, most events occurred in patients with non-obstructive but high-risk plaque phenotype. Conclusion In cancer survivors undergoing CCTA, high-risk plaque phenotype predicted short-term cardiovascular events despite low prevalence of obstructive disease. CCTA plaque characterisation may enable more targeted preventive strategies in cardio-oncology practice.