Plaque Vulnerability and Cardiovascular Risk Factor Burden in Acute Coronary Syndrome: An Optical Coherence Tomography Analysis

Background: Cardiovascular risk factors are strongly associated with adverse clinical outcomes, including acute coronary syndrome (ACS). Although individual risk factors have been related to specific plaque phenotypes, the relationship between the cumulative number of risk factors and plaque vulnerability has not been systematically explored. Objectives: The purpose of this study was to investigate the association between the number of cardiovascular risk factors and plaque vulnerability defined by optical coherence tomography. Methods: Patients with ACS were divided into 5 groups based on their number of traditional risk factors (diabetes, hypertension, hyperlipidemia, smoking) or into 2 groups (0-1 vs ≥2 risk factors). Features of vulnerability in both culprit and nonculprit lesions were analyzed. Results: Of 2,187 plaques analyzed, 1,581 were culprit and 606 nonculprit plaques. In culprit plaques, the prevalence of lipid-rich plaques (P trend = 0.027), thin-cap fibroatheromas (P trend = 0.006), macrophages (P trend <0.001), microvessels (P trend <0.001), and cholesterol crystals (P trend = 0.032) increased as the number of risk factors increased. The presence of ≥2 risk factors was independently associated with all vulnerable features except lipid-rich plaques. Plaque rupture showed an increasing prevalence as the number of risk factors increased (P trend = 0.015), whereas plaque erosion showed a decreasing trend (P trend <0.001). In nonculprit plaques, only macrophages, cholesterol crystals, and the cumulative number of vulnerable features in each plaque exhibited a significant positive association with the number of risk factors. Conclusions: In patients with ACS, an increasing number of cardiovascular risk factors were strongly associated with greater plaque vulnerability, especially for culprit lesions. These findings may explain the relationship between traditional risk factors and adverse clinical outcomes.