Forty-Eight Hour Lactate Normalization Predicts Favorable Neurologic Recovery and Survival in Venoarterial ECMO for Cardiogenic Shock

Extracorporeal membrane oxygenation (ECMO) for cardiogenic shock (CS) is associated with high mortality and poor neurological outcomes. Dynamic assessment of metabolic recovery, reflected by lactate normalization, may offer additional prognostic value compared with static severity indices. We retrospectively analyzed 662 consecutive patients from the multicenter RESCUE II registry who remained on venoarterial ECMO for at least 48 hours. Patients were stratified by 48 hour lactate level: 48 hour lactate normalization group (< 2.0 mmol/L, n = 371) and persistent lactate elevation group (≥ 2.0 mmol/L, n = 291). The primary outcome was favorable neurologic discharge (FND), defined as discharge with a Cerebral Performance Category score of 1 or 2. The persistent lactate elevation group had a higher SOFA score (9.8 ± 3.2 vs. 8.5 ± 3.4, p < 0.001) and initial serum lactate (7.9 ± 4.8 mmol/L vs. 6.0 ± 4.3 mmol/L, p < 0.001). Lactate normalization was associated with a higher rate of FND (71.4% vs. 41.9%, p < 0.001), remained an independent predictor of FND (odds ratio [OR]: 3.12, 95% confidence interval [CI]: 2.21-4.41, p < 0.001), and was associated with lower risks of all-cause death (hazard ratio [HR]: 0.49, 95% CI: 0.38-0.64, p < 0.001) at 12 months. In conclusion, lactate normalization within 48 hours of ECMO initiation is associated with favorable neurologic status and 12 month survival.