Long-Term Impact of Peritoneal Dialysis Ultrafiltration on Cardiorenal Patients

BACKGROUND: Heart failure (HF) prevalence is increasing, and its prognosis worsens in the presence of other comorbidities. Up to 70% of patients develop cardiorenal syndrome (CRS), which is associated with diuretic resistance or kidney deterioration over time. Peritoneal dialysis (PD) for ultrafiltration (PD-UF) could be a potential therapeutic option in CRS, although its long-term outcomes have not been described. METHODS: Retrospective registry study of the Catalan Renal Registry on patients with PD-UF indication between 2013 and 2022. Baseline clinical characteristics and follow-up until December/2022 was studied. RESULTS: Of the 1,874 incident patients on PD, 198 (10.6%) were PD-UF, 73.2% of the patients were male, and the mean age was 70.7 ± 9.3 years. Median estimated glomerular filtration rate (eGFR) at start was 22.6 (IQR: 14.8-32.8) mL/min×1.73 m2 and 75.0% have an eGFR above 15 mL/min×1.73 m2. Previous history of ischemic heart disease, arrhythmia, or cardiac surgery was recorded, and 57.6% of patients had ≥2 of these pathologies. The most common HF etiology was ischemic heart disease in 21.7% of patients. Median overall patient survival was 21 (IQR: 17.3-24.3) months. Technique survival at 1 year was 94.8%, and 27 patients were transferred to other renal replacement therapy (hemodialysis or kidney transplantation). In the Cox multivariate analysis, age ≥75 years (HR: 1.76 [95% CI: 1.20-2.59]), mild frailty (HR: 2.18 [95% CI: 1.17-2.59]), severe frailty (HR: 17.62 [95% CI: 1.20-55.48]), and the burden of cardiac disease (2 categories HR: 2.17 [95% CI: 1.05-4.47]; 3 categories HR: 2.26 [95% CI: 1.05-4.89]) were associated with poor overall survival. Technique survival was associated with eGFR (<30 mL/min×1.73 m2 HR: 5.64 [95% CI: 1.32-24.18]) and body mass index (<20 kg/m2 HR: 6.53 [95% CI: 1.06-40.12]) at baseline. CONCLUSION: PD-UF is a feasible option in patients with advanced HF and CRS. The complexity of this population increases with older age, frailty, and higher cardiac burden.