Abstract
BACKGROUND: The optimal timing of left ventricular unloading in patients with cardiogenic shock receiving venoarterial extracorporeal membrane oxygenation therapy remains controversial. This systematic review evaluated the latest evidence on the impact of left ventricular unloading timing in patients with cardiogenic shock receiving venoarterial extracorporeal membrane oxygenation. METHODS: The PubMed, Embase and Cochrane Library databases were searched from inception to February 2025. The identified studies were screened based on predefined inclusion and exclusion criteria, and eligible studies were subjected to quality assessment and data extraction. Heterogeneity testing and meta-analysis were performed using Review Manager software version 5.4. RESULTS: Eight studies involving 2,117 patients (proactive unloading, 1,338; passive unloading, 779) were included in the meta-analysis, which revealed no statistically significant differences in extracorporeal membrane oxygenation weaning rates (relative risk = 1.06, 95% confidence interval: 0.87-1.28; P = 0.59), in-hospital mortality (relative risk = 0.95, 95% confidence interval: 0.86-1.04; P = 0.28), or 30-day all-cause mortality (relative risk = 0.75, 95% confidence interval: 0.52-1.10; P = 0.14) between the proactive and passive unloading groups. However, the risks of sepsis (relative risk = 0.79, 95% confidence interval: 0.64-0.96; P = 0.02) and abdominal complications (relative risk = 0.67, 95% confidence interval: 0.46-0.96; P = 0.03) were lower following proactive unloading than following passive unloading. CONCLUSION: Compared to passive left ventricular unloading, proactive left ventricular unloading did not confer significant benefits in terms of extracorporeal membrane oxygenation weaning success or short-term survival outcomes, but was associated with reduced risks of sepsis and abdominal complications. REGISTRATION: The review protocol was registered in PROSPERO (ID: CRD42024499028).