Evaluating the Independent Impact of Renal Function Decline on Coronary Artery Calcification in Patients Undergone Cardiac CT Scan

Abstract

Background: Cardiovascular events are the leading global cause of death. Calcification of coronary arteries is a common complication of renal failure and the leading cause of death in this population. However, its multifactorial mechanism is not fully understood. Objectives: The current study aimed to, firstly, investigate the association between renal dysfunction and the calcification of coronary arteries in patients with severe and milder stages of renal failure and, secondly, to determine the role of this variable by eliminating the effect of established confounding factors. Methods: Following a retrospective design, 261 patients with cardiovascular risk factors or atypical symptoms were investigated. Estimated GFR (glomerular filtration rate) was calculated using both Cockcroft-Gault and MDRD equations. An ECG-gated multidetector CT scan was performed to calculate CACS (coronary artery calcification score) using the Agatston method. The presence of significant CAC (coronary artery calcification) was defined as CACS > 100. Univariate and multivariate analyses were performed using binary logistic regression. Results: A total of 134 cases were diagnosed with CAC, and the mean CACS was 83.4 ± 18. According to univariate analysis, older age, male gender, systolic and diastolic blood pressure, and higher TG levels were correlated with the degree of CAC. HbA1C showed a weak correlation with CACS (P-value = 0.04). Renal insufficiency resulted in increased CAC, and lower eGFR (calculated with both Cockgraft-Gault and MDRD equations) was associated with higher calcification (P-value < 0.01). Our analysis shows that serum Ca, P, LDL, and HDL levels do not have a significant influence on calcification changes. After adjusting for confounding factors, male sex, age, triglyceride level, and eGFR were recognized as independent risk factors for CACS ≥ 100, a marker of coronary artery atherosclerosis. However, HbA1C and systolic and diastolic blood pressure were no longer considered as factors that contribute to the risk of CAC. Conclusions: We observed a gradual and independent association between lower eGFR and higher CAC scores.