Prognostic value of syntax score, intravascular ultrasound and near-infrared spectroscopy to identify low-risk patients with coronary artery disease 5-year results from the ATHEROREMO and IBIS-3 cohorts

The prognostic value of SYNTAX score (SS), intravascular ultrasound (IVUS)-derived plaque burden (PB) and near-infrared spectroscopy (NIRS)-derived lipid core burden index (LCBI) for identification of high-risk patients for major adverse cardiovascular events (MACE) has been proven in previous studies. The majority of patients presenting in the cathlab however do not endure MACE over time, and identification of low-risk groups has remained underexposed. This study evaluates the combined prognostic value of SS, PB and LCBI in identifying patients with low MACE risk. This post-hoc analysis combines the ATHEROREMO and IBIS-3 studies and included 798 patients undergoing coronary angiography. Anatomical SS was calculated (N = 617) and ≥40mm non-stenotic segment of a non-target vessel was investigated with IVUS (N = 645) and NIRS (N = 273) to determine PB and maximum 4mm LCBI (LCBI _4mm). During five-year follow-up, 191 MACE were observed. Patients with PB ≤70%, LCBI _4mm ≤227 (median), or SS ≤8 (median) had lower MACE incidence than their counterparts with higher values. Combined into one model, LCBI _4mm ≤227 (adjusted hazard ratio [aHR] 0.49, 95% confidence interval [CI] 0.30–0.78; p-value = 0.003) and SS ≤8 (aHR 0.67, 95%CI 0.48–0.96, p-value = 0.027) were independently associated with (lower) MACE rate, but PB was not. Additionally, negative predictive value (NPV) of this model was high (SS<8: 0.80, PB<70%: 0.77, LCBI _4mm<227: 0.79). In this cohort, SS and LCBI _4mm proved to be independent predictors of MACE-free survival during five-year followup. Combination of SS and LCBI _4mm is useful to identify a low-risk population. Furthermore, NPV of SS, PB and LCBI _4mm for prediction of MACE is high.