Relationship between the Castelli risk indeces and the presence and severity of ischemia in non-geriatric patients with suspected coronary artery disease

Aims: This study aimed to investigate the relationship between ischemia severity and Castelli risk indices (CRI) levels in non-geriatric patients with suspected coronary artery disease (CAD) referred to myocardial perfusion scintigraphy (MPS) with gated single photon emission computed tomography (SPECT). Material and Methods: This retrospective study included 417 non-geriatric patients referred to SPECT MPS for suspected CAD at the Cardiology Clinic between January 2019 and January 2021. Patients were divided into normal, mild, moderate, and severe ischemia groups according to MPS. CRIs were calculated as follows: CRI-I = total cholesterol / HDL ratio; CRI-II = LDL / HDL ratio. Results: The CRIs levels were higher in ischemia group than non-ischemia group. Increase in CRI-II level was associated with increased ischemia severity. Increased CRI-II level was found to be an independent predictor of mild, moderate and severe ischemia group, but CRI-I was similar in moderate and severe ischemia groups. The threshold value of CRI-II for predicting the presence of ischemia was >2.1 (AUC ± SE = 0.787 ± 0.02, sensitivity = 79.5%, specificity = 71.4%). The threshold values of CRI-II showed a gradual increase in predicting the severity of ischemia. Conclusion: CRI-II offers offers gradually increasing threshold values in distinguishing patients with suspected CAD but without perfusion defects or determining its severity in the case of ischemia. CRI-II can be a potential screening tool for patients with suspected CAD and it can be used for risk stratification.