Risk Factors for Chronic Kidney Disease in Adult Patients with Congenital Heart Disease and Its Relationship with Cardiovascular Mortality

Abstract

Background: Patients with congenital heart disease (CHD) show risk factors for chronic kidney disease (CKD) and it is well known that CKD has a large negative impact on survival. Methods: Observational and prospective cohort study. Adult CHD patients and controls were matched for age and sex. Results: A total of 657 CHD adult patients (cases) and 1954 controls were studied. Median age in CHD patients was 30 (17–62) years and 373 (57%) were male. The prevalence of CKD (Glomerular filtration rate (GFR) < 60 mL/min/1.73 m2) was 0.2% and 4.5% in the control and CHD groups, respectively. Binary logistic regression analysis determined as risk factors for CKD in CHD patients: age [1.54 (1.04–1.28), p = 0.009], dyslipidemia [19.8 (1.35–301.1), p = 0.031], low iron concentration [0.96 (0.96–0.93), p = 0.048], cyanosis [25.7 (1.60–411.8), p = 0.022], and Down syndrome [46.8 (8.09–2710), p = 0.003]. During a follow-up time of 6.8 (1.2–10.5) years, cardiovascular mortality occurred in 31 patients with CHD showing, through the Kaplan–Meier test, a worse outcome among patients with CKD (p < 0.05) as was also seen in the univariate Cox regression survival analysis. However, after adjusting for other variables, this significance was lost, with age remaining as the unique independent prognostic factor. Conclusions: The prevalence of CKD was much higher in patients with CHD than in the control group; age, cyanosis, and Down syndrome were the predictors of a higher risk of CKD among CHD patients. Although CKD was associated with worse survival in CHD patients, only age was identified as an independent prognostic factor for cardiovascular mortality.