Abstract Body (Do not enter title and authors here):
Background:
In a growing and aging adult population with congenital heart disease (CHD), the prevalence of renal dysfunction is increasing. There is paucity of information regarding the prevalence, spectrum of and outcomes in adult CHD patients with end-stage kidney disease (ESKD).

Aims:
To determine baseline characteristics of adult patients with ESKD and CHD, grouped by complexity, and to compare their mortality and morbidity outcomes to non-CHD patients.

Methods:
We analyzed the United States Renal Data System to identify patients ≥ 18 years of age initiating long-term dialysis between 2006 and 2020. Patients were grouped by complexity of CHD - Simple, Moderate and Complex based on ICD codes. We assessed mortality and hospitalization outcomes at 1 and 3 years by comparing percentages and adjusted hazard ratios using the Fine-Gray sub distribution hazard model. Kaplan-Meier curves were also generated.

Results:
A total of 1513 patients with CHD were identified. The mean age was 65.8 years with complex CHD being the youngest cohort. About 55% of patients were male and White race was the most prevalent. While patients with CHD had a higher prevalence of heart failure and arrhythmias at baseline, patients with complex CHD had especially unique characteristics. They demonstrated a higher prevalence of liver disease, thromboembolism, and causes of ESKD not related to hypertension or diabetes; a lower prevalence of CAD and CVA/TIA; and a shorter time to first hospitalization. Patients with simple [HR 0.67 95% CI (0.53 – 0.85)] and moderate CHD [HR 0.70 (0.60 – 0.81)] had significantly less mortality at 1 year compared to non-CHD patients, with similar findings at 3 years. Hospitalization rates and admissions for CHF exacerbation at 1 year and 3 years were significantly higher amongst all CHD patients, especially in complex CHD (80.4% vs 61.4% in non-CHD patients at 1 year). Kaplan-Meier curves (see Figure) over a 10-year follow-up showed significantly lesser mortality and increased hospitalizations amongst CHD patients (p <0.0001).

Conclusion:
Patients with CHD and ESKD have better long-term survival than patients without CHD upon initiating dialysis despite higher rates of hospitalizations and heart failure admissions.