Background <p>Acute kidney injury (AKI) is a common and serious complication in the intensive care unit (ICU), and continuous renal replacement therapy (CRRT) is an important treatment option. However, there is no clear standard for the optimal time to stop CRRT. The cardiorenal interaction effect suggests that there may be a potential link between cardiac function and CRRT. This study aimed to investigate the left ventricular diastolic function for predicting CRRT discontinuation.</p> Methods <p>This is a prospective cohort study.</p> Results <p>The study included 154 AKI patients admitted to ICUs undergoing CRRT from February 2023 to August 2024, which were divided into the successful downtime group (87 patients) and the failure group (67 patients), and their baseline data, laboratory indices, and ultrasound parameters were analyzed. The results showed that serum creatinine, urea nitrogen, and E/eʹ measured at the time of CRRT discontinuation were significantly lower in the successful group than in the unsuccessful group (all <i>P</i> &lt; 0.05). A higher E/eʹ measured at the time of CRRT discontinuation was associated with a lower likelihood of successful CRRT discontinuation (OR 0.71, 95% CI 0.61–0.83). Receiver operating characteristic analysis showed that E/eʹ at the time of CRRT discontinuation had good discriminative ability for successful discontinuation (AUC 0.832), with an empirically derived cut-off value of 8.62.</p> Conclusion <p>Our findings suggest that left ventricular diastolic function is associated with successful CRRT discontinuation in patients with AKI, and that E/eʹ may serve as a supportive, noninvasive parameter to complement clinical assessment at the time of CRRT discontinuation.</p>