# Treatment with Rasburicase in Hospitalized Patients with Cardiorenal Syndrome: Old Treatment, New Scenario

## TL;DR

Rasburicase, typically used for tumor lysis syndrome, effectively improves kidney function and reduces congestion in patients with cardiorenal syndrome and high uric acid.

## Contribution

Demonstrates rasburicase's effectiveness in cardiorenal syndrome, a new application beyond its traditional use in tumor lysis syndrome.

## Key findings

- Rasburicase improved diuresis and reduced systemic congestion in 35 patients with cardiorenal syndrome.
- 86% of patients avoided renal replacement therapy after treatment, with significant decreases in creatinine and increases in eGFR.
- Nt-ProBNP and CRP levels were significantly reduced, indicating improved cardiac and inflammatory markers.

## Abstract

Cardiorenal syndrome (CRS) involves joint dysfunction of the heart and kidney. Acute forms share biochemical alterations like hyperuricaemia (HU) with tumour lysis syndrome (TLS). The mainstay treatment of acute CRS with systemic overload is diuretics, but rasburicase is used in TLS to prevent and treat hyperuricaemia. An observational, retrospective study was performed to assess the effectiveness and safety of a single dose of rasburicase in hospitalized patients with cardiorenal syndrome, worsening renal function and uric acid levels above 9 mg/dL. Rasburicase improved diuresis and systemic congestion in the 35 patients included. A total of 86% of patients did not need to undergo RRT, and early withdrawal was possible in the remaining five. Creatinine (Cr) decreased after treatment with rasburicase from a peak of 3.6 ± 1.27 to 1.79 ± 0.83 mg/dL, and the estimated glomerular filtration rate (eGFR) improved from 17 ± 8 to 41 ± 20 mL/min/1.73 m2 (p = 0.0001). The levels of N-terminal type B Brain Natriuretic Peptide (Nt-ProBNP) and C-reactive protein (CRP) were also significantly reduced. No relevant adverse events were detected. Our results show that early treatment with a dose of rasburicase in patients with CRS and severe HU is effective to improve renal function and systemic congestion, avoiding the need for sustained extrarenal clearance, regardless of comorbidities and ventricular function.