Continuous Renal Replacement Therapy and Extracorporeal Membrane Oxygenation in Patients with Cardiogenic Shock: Results from the Rescue Registry

<b>Background:</b> Cardiogenic shock (CS) frequently leads to multiorgan failure, often necessitating continuous renal replacement therapy (CRRT) or extracorporeal membrane oxygenation (ECMO). We evaluated the association between CRRT, ECMO, and its prognostic implication in patients with CS. <b>Methods:</b> A total of 1247 patients with CS were enrolled from the RESCUE (Retrospective and Prospective Observational Study to Investigate Clinical Outcomes and Efficacy of Left Ventricular Assist Device for Korean Patients with Cardiogenic Shock) registry between January 2014 and December 2018. The primary outcomes, including the 72 h and 30-day all-cause mortality rates, were analyzed in relation to the use of ECMO and CRRT among CS patients. <b>Results:</b> Among 751 non-ECMO patients, 90 (12%) underwent CRRT, while among 496 ECMO patients, 195 (39.3%) underwent CRRT. Overall, CRRT was associated with higher 30-day mortality. However, among ECMO patients, CRRT was linked to lower 72 h mortality (19.6% versus 12.3%; <i>p</i> = 0.045). Multivariate analysis showed that CRRT reduced 72 h mortality in ECMO patients (hazard ratio: 0.44; 95% confidence interval: 0.21-0.91; <i>p</i> = 0.027). Independent predictors for CRRT included an estimated GFR < 44 mL/min/1.73 m², mechanical ventilation, ECMO use, IABP use, and increased lactate. <b>Conclusions:</b> CS patients receiving CRRT had higher 30-day mortality. Nonetheless, CRRT administration was more common in ECMO patients, potentially improving early in-hospital clinical outcomes.