Impact of dialysis adequacy on cardiac function in pediatric CAPD patients

Abstract

Background: Left ventricular hypertrophy is a major cause of morbidity and mortality among patients with chronic renal failure. Uremia-related risk factors play a fundamental role in its occurrence, thus better prognosis and prolonged survival can be attained by successful dialytic therapies.

Objective: To investigate whether dialysis adequacy has a beneficial effect on cardiac structure and function in children receiving continuous ambulatory peritoneal dialysis (CAPD).

Design: Cross-sectional study in the Pediatric Peritoneal Dialysis Unit of a university hospital.

Patients: Eighteen children, aged 13.3 +/- 2.8 years, being treated with CAPD, and 20 healthy age- and sex-matched control subjects were enrolled in this study.

Main outcome measures: Echocardiographic evaluation was performed in all subjects. Dialysis adequacy indices [weekly urea (Kt/V) and creatinine clearance (TCCr)] were calculated in the dialysis group.

Results: Interventricular septal thickness, left ventricular (LV) posterior wall thickness, LV mass index (LVMI), and LV end systolic and diastolic dimensions were all found to be significantly higher in the CAPD group compared to the control subjects (p < 0.01). Ejection fraction and fractional shortening of the LV were not significantly different between the two groups. Mean Kt/V was 2.02 +/- 0.71 and mean TCCr was 58 +/- 33 L/wk/1.73 m2. There were significant negative correlations between dialysis adequacy indices and LV end systolic and diastolic dimensions (p < 0.05 and p < 0.001). Ejection fraction and fractional shortening were positively correlated with Kt/V (p < 0.01). Systolic and diastolic blood pressures were positively correlated with LVMI (r= 0.501 and r = 0.523). Significant inverse correlations between mean arterial pressure and both Kt/V and TCCr (r = -0.555 and r = -0.520) were detected.

Conclusion: These data clearly document that cardiac structure and function are remarkably influenced by the uremic state and dialysis therapy in pediatric CAPD patients. The close relationships between echocardiographic findings and dialysis adequacy indices suggest that adequate dialysis has a beneficial effect on cardiac function via effective removal of toxic substances.