Cholesterol crystals as a predictor of slow flow/no-reflow phenomenon in acute coronary syndrome

Abstract Background No-reflow phenomenon is a critical factor affecting the acute-phase treatment outcomes of acute myocardial infarction (AMI). Despite being an independent predictor of mortality following percutaneous coronary intervention (PCI), predicting slow flow/no-reflow phenomenon during PCI remains challenging. Mechanical stimulation of vulnerable plaques can cause fragmentation of plaque components, such as thrombi, lipids, and inflammatory cells, which may embolize peripheral arteries and lead to slow flow/no-reflow phenomenon. Cholesterol crystals are known to be released into the bloodstream from ruptured vulnerable plaques and are increasingly recognized as markers of plaque rupture. A novel technique, the filter paper rinse method, has recently been reported as a means to detect cholesterol crystals in coronary artery blood samples. However, no studies have evaluated the relationship between the detection rate of cholesterol crystals in blood samples aspirated from culprit lesions in AMI and the frequency of slow flow/no-reflow phenomenon. Objective To investigate the association between the detection rate of cholesterol crystals in culprit lesions of AMI and the frequency of slow flow/no-reflow phenomenon. Methods and Results This study analyzed 90 consecutive AMI patients admitted to the Cardiac Care Unit (CCU) of our hospital. Blood samples aspirated from culprit lesions were examined for the presence of cholesterol crystals using the filter paper rinse method. Cholesterol crystals were detected in 35 cases. Patients with detected cholesterol crystals were older and had a significantly higher incidence of slow flow/no-reflow phenomenon compared to those without cholesterol crystals (p = 0.014, p = 0.043, respectively). Additionally, positive remodeling on intravascular ultrasound (IVUS) and the presence of thrombi in blood samples were more frequently observed in the cholesterol crystal-positive group (p 0.001, p 0.001, respectively). Univariate analysis identified positive remodeling on IVUS, the presence of thrombi in blood samples, and the presence of cholesterol crystals as predictors of slow flow/no-reflow phenomenon (p = 0.032, p = 0.018, p 0.001, respectively). Multivariate analysis revealed that among these factors, only the presence of cholesterol crystals was an independent predictor of slow flow/no-reflow (p = 0.006). Conclusion The detection of cholesterol crystals using the filter paper rinse method may serve as a valuable tool for assessing the characteristics of culprit lesions in AMI, which conventional methods cannot evaluate. Furthermore, the presence of cholesterol crystals in blood samples aspirated from culprit lesions may play a crucial role in guiding treatment strategies for acute myocardial infarction.Cholesterol crystal from a blood sample