# Rapid-onset postoperative acute kidney injury is associated with mortality in patients with postcardiotomy cardiogenic shock

## TL;DR

Rapid-onset kidney injury after heart surgery is linked to higher death rates in patients needing heart support machines.

## Contribution

This study identifies rapid-onset acute kidney injury as an independent predictor of 90-day mortality in post-cardiotomy cardiogenic shock patients.

## Key findings

- Rapid-onset AKI was associated with a 3.15-fold higher risk of 90-day mortality.
- Patients with rapid-onset AKI had lower survival rates and longer mechanical support durations.
- The study confirms AKI as an independent mortality predictor in post-cardiotomy cardiogenic shock.

## Abstract

Post-cardiotomy cardiogenic shock (PCCS) is a serious condition that necessitates veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Although acute kidney injury (AKI) often complicates PCCS, its specific effects on patient outcomes remain unclear. This study seeks to evaluate the impact of AKI on 90-day mortality.

This retrospective study included 91 patients with postoperative cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation following cardiac surgery between 2013 and 2023. Rapid-onset AKI was defined as KDIGO Stage 2 or higher within 24 h of ICU admission. Survival was analyzed using Kaplan–Meier and Cox regression methods to assess its association with 90-day mortality.

Twenty-four patients (26.4%) were classified as rapid-onset AKI. The median age, primary diagnosis, and preoperative serum creatinine levels were similar between groups. However, the rapid-onset AKI group had a preoperative lower left ventricular ejection fraction (42.5% vs. 60.0%, p = 0.006), longer cardiopulmonary bypass time (332 vs. 245 min, p = 0.009), and a longer duration of mechanical circulatory support (6.0 vs. 2.0 days, p = 0.001). The success rate of weaning from mechanical circulatory support was lower (61.1% vs. 93.3%, p = 0.002), and the 90-day cumulative survival probability was lower in the rapid-onset AKI group (29.1% [95% confidence interval (CI): 15.6–54.4 vs. 79.1% [95% CI: 69.9–89.4], p < 0.001). Cox regression analysis confirmed an independent association between rapid-onset AKI and 90-day mortality (adjusted hazard ratio: 3.15, 95% CI: 1.38–7.19, p = 0.006).

Rapid-onset AKI was significantly associated with increased 90-day mortality in patients with PCCS who required V-A ECMO.