Is there a relationship between slow coronary flow and normal to mildly impaired renal function?

Objective: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation is more effective at estimating glomerular filtration rate (GFR) than the Modification of Diet in Renal Disease (MDRD) equation, particularly in patients with mildly impaired renal function. Recent studies have demonstrated, using the Cockroft-Gault and MDRD formulas, a significant correlation between slow coronary flow (SCF) and normal to mildly impaired renal function. However, these studies had some limitations. The aim of the present study was to investigate the relationship between SCF and normal to mildly impaired renal function using the CKD-EPI equation. Methods: A total of 370 patients were included, 172 with normal coronary flow (NCF) and 198 with SCF. All participants had normal to mildly impaired renal function. Both the CKDEPI and MDRD formulas were used to calculated estimated glomerular filtration rate (eGFR), which was compared between groups. Results: No significant difference in mean values of eGFR was found between the NCF and SCF groups (CKD-EPI: 92.9+-14.7 vs 92.7+-14.2, p=0.72; MDRD: 89.5+-19.5 vs 88.2+-17.0, p=0.70, respectively). Among patients with eGFR(MDRD) ≥90 mL/ min/1.73 m2, mean eGFR levels were lower among patients with SCF (107.0+-12.7 vs 102.7+-10.0, p=0.02). Conclusion: No correlation was found between SCF and normal to mildly impaired renal function.