Echocardiographic Findings in Patients with Mild to Moderate Chronic Kidney Disease without Symptomatic Heart Failure: A Population-Based Study

BACKGROUND: Renal dysfunction is an established risk factor for cardiovascular disease, but early disease states in both organs are poorly studied.

OBJECTIVE: This cross-sectional population-based study aims to investigate if there is an early association between kidney function and echocardiographic markers of cardiac structure and diastolic function.

METHODS: The study population consisted of 1,504 individuals with no prior history of congestive heart failure or asymptomatic left ventricular ejection fraction ≤40% and an estimated glomerular filtration rate (eGFR) based on cystatin C >15 mL/min/1.73 m2. The participants were categorized according to eGFR ≥90, 75-89, 60-74, 45-59, 30-44, and 15-29 mL/min/1.73 m2. We evaluated associations between eGFR categories and echocardiographic findings specific to cardiac structure and diastolic function.

RESULTS: Associations between eGFR categories and echocardiographic findings were found for left atrium area/body surface area (p = 0.013) indicating structural changes, and peak early mitral valve velocity (A; p = 0.003), peak late atrial mitral valve velocity/peak systolic myocardial velocity at mitral annulus in the lateral wall (E/Élat; p = 0.002), É mean of lateral and septal wall/Á mean of lateral and septal wall (mean É/Á; p = 0.027) indicating diastolic dysfunction. Associations between E/Élat and mean É/Á and eGFR categories were already present in individuals with eGFR 45-60 mL/min/1.73 m2. In sex-specific analysis these associations were only significant among men.

CONCLUSION: A significant association between mild to moderate impairment of renal function and echocardiographic markers of cardiac structure and diastolic function was observed, supporting the hypothesis that interaction between the kidney and heart exists even in the early stages of renal impairment.