Renal microcirculatory impairment on contrast enhanced ultrasound predicts persistent renal impairment in cardiogenic shock patients receiving venoarterial extracorporeal membrane oxygenation

Abstract Acute kidney injury (AKI) is one of the most frequent complications in patients with cardiogenic shock (CS) receiving veno‑arterial extracorporeal membrane oxygenation (VA-ECMO). Microcirculation dysfunction is an important mechanism and it can be effectively evaluated by contrast-enhanced ultrasound (CEUS). This study aimed to investigate the association between CEUS-derived parameters and the progression of persistent renal impairment following AKI in this population. This prospective observational study involved 127 CS patients receiving VA-ECMO and developing AKI within 48 h. All patients underwent CEUS at 48 h after ECMO initiation. The study endpoint was the non-recovery of renal function at the 7, 30 and 90 days after ECMO initiation. CEUS-derived parameters included time to peak (TTP), rise time (RT) and time from peak to one half (TPH). Logistic regression was used to identify the correlation between these parameters and study endpoints. Additionally, seven machine learning (ML) algorithms were employed to validate the comprehensive predictive power of CEUS parameters. The proportions of AKI non-recovery at 7, 30 and 90 days were 67.72%, 37.79%, and 23.62% respectively. The univariate and multivariate logistic regression analysis for the clinical outcomes demonstrated increased TTP, RT and TPH in both cortex and medulla were associated with increased risk of AKI non-recovery at 7, 30, and 90 days (all P < 0.05). All ML algorithms demonstrated acceptable discrimination in predicting endpoints. CEUS may be a valuable tool for assessing renal microcirculation alterations. CEUS-derived indices were effective in predicting the progression of renal impairment after AKI.