Impact of clinical risk characteristics on the prognostic value of high-risk plaques

High-risk coronary plaques (HRPs) are associated with adverse cardiovascular outcomes. However, the clinical practicality of HRP identification is challenged by their modest prevalence and low positive predictive value. We aimed to evaluate the association between clinical risk factors and HRPs, as well as the clinical impact of HRPs across different clinical risk profiles. This is a pooled analysis of individual patient data from the prospective observational COMBINE (OCT-FFR) and PECTUS-obs studies. A modified version of the Thrombolysis in Myocardial Infarction Risk Score for Secondary Prevention (TRS-2P) was used for risk stratification. The composite endpoint of major adverse cardiovascular events (MACE) was evaluated on a patient level, and target lesion failure (TLF), also a composite endpoint, was evaluated on a lesion level. Among 810 patients, 311, 265, and 234 were at low (TRS-2P 0-1), intermediate (TRS-2P 2), and high risk (TRS-2P ≥3), respectively. The modified TRS-2P had no discriminative value for the identification of patients with an HRP (area under the receiver operating characteristic curve 0.51, 95% confidence interval [CI]: 0.47-0.56). A consistent trend towards worse clinical outcome in the presence of an HRP was observed across different clinical risk profiles (pinteraction=0.539 for MACE and 0.337 for TLF). For TLF, the highest event rate per 100 lesion-years was observed in high-risk patients with HRPs (6.28, 95% CI: 3.52-10.36; 13.6% absolute risk at 2 years). HRPs are associated with a negative clinical outcome, without apparent differences between clinical risk profiles. This highlights the independent value of optical coherence tomography for prognostication beyond clinical risk factors. The high event rates in high-risk patients with HRPs necessitate the search for additional therapeutic strategies to mitigate this risk.