Ratio of Transmitral E Wave Velocity to Early Diastole Mitral Velocity and Albumin with Renal Outcomes in Chronic Kidney Disease

Abstract

BACKGROUND: Left ventricular diastolic dysfunction is frequently observed in patients with chronic kidney disease (CKD), even in early stages. The ratio of transmitral E wave velocity (E) to early diastole mitral velocity (Ea), an estimate of left ventricular filling pressure, predicts mortality in various populations. This study examined the association between E/Ea and albumin and assessed whether the combination of E/Ea and albumin was independently associated with renal outcomes in patients with CKD stages 3-5. METHODS: This longitudinal study enrolled 293 patients who were classified into four groups according to median values of E/Ea and albumin. The change in renal function was measured by the slope of estimated glomerular filtration rate (eGFR). Rapid renal progression was defined as eGFR slope of less than -3 mL/min/1.73 m^2/year. The renal end point was defined as commencement of dialysis. RESULTS: Albumin was significantly associated with E/Ea (un-standardized coefficient β = -1.526, P = 0.048). During a median of 28.1 months of follow-up period, 63 patients started dialysis (21.5%). In multivariate analysis, the group with higher E/Ea and lower albumin (vs. the group with lower E/Ea and higher albumin) showed an independent association with rapid renal progression (odds ratio, 3.410; 95% confidence interval ICII, 1.399 to 8.310; P = 0.007) and chance of progression to dialysis (hazard ratio, 2.729; 95% CI, 1.213 to 6.143; P = 0.015). CONCLUSION: The current findings show that albumin is independently associated with E/Ea and suggest that the combination of increased E/Ea and hypoalbuminemia is independently associated with rapid renal progression and progression to dialysis in patients with CKD. Measurements of serum albumin and E/Ea by echocardiography are useful for predicting the risk for adverse renal outcomes.