# Limiting the gamble: Risk and predictability for renal replacement therapy in patients receiving mechanical circulatory support

## TL;DR

This study finds that patients on heart support devices are more likely to need kidney treatment if they have certain medical histories or devices, and common blood thinners don't help much.

## Contribution

Identifies novel associations between immunologic therapy, pacemakers/ICDs, and the need for RRT in MCS patients.

## Key findings

- 36% of MCS patients required RRT, with a confidence interval of 29% to 44%.
- Patients with immunologic therapy or pacemakers/ICDs had a higher risk of needing RRT.
- Unfractionated heparin did not significantly reduce the need for RRT in these patients.

## Abstract

Background: Patients receiving mechanical circulatory support (MCS) frequently require renal replacement therapy (RRT). Examining risk factors for requiring RRT in patients receiving MCS may allow improved understanding of these comorbidities and enhance patient outcomes. Methods: Following IRB approval, patient characteristics, comorbidities, and the need for RRT were studied in 129 patients who received MCS from January 2017 to October 2023. The clinical variables underwent machine learning to examine their relationships to the outcome of interest, the need for RRT. Results: In this study, the incidence of RRT was 36% with a 95% confidence interval ranging from 29% to 44%. Following machine learning, patients with a history of immunologic therapy or having a pacemaker or internal cardiac defibrillator (ICD) were associated with the need for RRT (χ2 = 44, P = 0.0003). The c-index statistic for this model was 0.81. The anticoagulation therapy administered in these two groups was also analyzed. Patients in these two groups receiving unfractionated heparin were observed to have a higher incidence (44%) in the need for RRT. Conclusion: The incidence of RRT was high in this patient population. The novel associations in patients requiring MCS who have received prior immunologic therapy or have pre-existing pacemaker/ICDs suggest that an increased systemic inflammatory state exists that escalates the need for RRT. Unfractionated heparin appears to provide minimal protection from the need for RRT in patients requiring MCS. These findings suggest that other options for systemic anticoagulation in patients requiring MCS should be considered. Further investigation into how these background inflammatory conditions contribute to the need for RRT in patients requiring MCS is warranted.