Non-obstructive high-risk plaques increase the risk of future culprit lesions comparable to obstructive plaques without high-risk features: the ICONIC study
Richard Ferraro, Alexander R. van Rosendael, Yao Lu, Daniele Andreini, Mouaz H. Al‐Mallah, Filippo Cademartiri, Kavitha M. Chinnaiyan, Benjamin J.W. Chow, Edoardo Conte, Ricardo C. Cury, Gudrun Feuchtner, Pedro de Araújo Gonçalves, Martin Hadamitzky, Yong‐Jin Kim, Jonathon Leipsic, Erica Maffei, Hugo Marques, Fabian Plank, Gianluca Pontone, Gilbert Raff, Todd C. Villines, Sang‐Eun Lee, Subhi J. Al’Aref, Lohendran Baskaran, Iksung Cho, Ibrahim Danad, Heidi Gransar, Matthew J. Budoff, Habib Samady, Peter H. Stone, Renu Virmani, Jagat Narula, Daniel S. Berman, Hyuk‐Jae Chang, Jeroen J. Bax, James K. Min, Leslee J. Shaw, Fay Y. Lin
Abstract
AIMS: High-risk plaque (HRP) and non-obstructive coronary artery disease independently predict adverse events, but their importance to future culprit lesions has not been resolved. We sought to determine in patients prior to confirmed acute coronary syndrome (ACS) the association between lesion percent diameter stenosis (%DS), and the absolute number and prevalence of HRP. The secondary objective was to examine the relative importance of non-obstructive HRP in future culprit lesions. METHODS AND RESULTS: Within the ICONIC study, a nested case-control study of patients undergoing coronary computed tomographic angiography (coronary CT), we included ACS cases with culprit lesions confirmed by invasive coronary angiography and coregistered to baseline coronary CT. Quantitative CT was used to evaluate obstructive (≥50%) and non-obstructive (<50%) diameter stenosis, with HRP defined as ≥2 features of spotty calcification, positive remodelling, or low-attenuation plaque at baseline. A total of 234 patients with downstream ACS over 54 (interquartile range 5-525.5) days exhibited 198/898 plaques with HRP on coronary CT. While HRP was less prevalent in non-obstructive (19.7%, 161/819) than obstructive lesions (46.8%, 37/79, P < 0.001), non-obstructive plaque comprised 81.3% (161/198) of HRP lesions overall. Among the 128 patients with identifiable culprit lesion precursors, the adjusted hazard ratio (HR) was 1.85 [95% confidence interval (CI) 1.26-2.72] for HRP, with no interaction between %DS and HRP (P = 0.82). Compared to non-obstructive HRP lesions, obstructive lesions without HRP exhibited a non-significant HR of 1.41 (95% CI 0.61-3.25, P = 0.42). CONCLUSIONS: While HRP is more prevalent among obstructive lesions, non-obstructive HRP lesions outnumber those that are obstructive and confer risk clinically approaching that of obstructive lesions without HRP.