The low hemoglobin levels were associated with mortality in post-cardiotomy patients undergoing venoarterial extracorporeal membrane oxygenation

Background Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used as a rescue strategy for patients with refractory post-cardiotomy cardiogenic shock (PCS). These patients often have varying degrees of reduced hemoglobin levels, and there are few detailed investigations about the impact of hemoglobin level on their mortality. The objective of this study was to evaluate whether hemoglobin levels at day 1 from VA-ECMO initiation were associated with in-hospital mortality. Methods We performed a retrospective analysis of adult VA-ECMO patients over approximately a 2-year period. We divided patients into survival and death groups based on their clinical outcomes and compared the differences in parameters between the two groups. Multivariate logistic regression analyses were performed to estimate whether hemoglobin level was related to the mortality. Results One hundred and sixteen patients were included in final analysis. There were 52 patients in the survival group and 64 in the death group. The patients were younger in the survival group than the death group (58 vs 63, p = .023). The median (IQR) hemoglobin level at day 1 was 80 (73−89) × g/L, and the median (IQR) RelΔ hemoglobin was 41% (32–48%). Survival patients had a higher hemoglobin level at day 1 and a lower RelΔ hemoglobin than the death patients (91 vs 76 g/L, p < .001; 35% vs 45%, p < .001). The multivariable logistic regression analyses showed that the low hemoglobin levels at day 1 were independently associated with in-hospital mortality (OR 0.808; 95% CI, 0.747–0.874; p < .001). The AUROC for hemoglobin level was 0.89 (95% CI, 0.83–0.95) which was better than that of RelΔ hemoglobin (0.77, 95% CI, 0.68–0.86). Conclusions In patients receiving VA-ECMO for PCS, the low hemoglobin levels at day 1 were independently associated with in-hospital mortality.