Risk factors for in-hospital mortality in elderly patients receiving veno-venous extracorporeal membrane oxygenation: A single-center retrospective study

BACKGROUND: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is an established therapy for severe respiratory failure; however, few studies have examined the validity of and prognostic factors for VV-ECMO implementation in elderly patients. OBJECTIVES: The present study attempted to identify factors associated with in-hospital mortality in elderly patients receiving VV-ECMO. METHODS: This retrospective cohort study analyzed patients who received VV-ECMO at a tertiary care center in Japan. Clinical data were collected from electronic medical records. Variables associated with in-hospital mortality were examined using univariate and multivariate logistic regression analyses. RESULTS: Seventy-nine patients were included in the analysis. Median age was 70 years (interquartile range 59-79). Mortality rates increased with age: 14.3% (<49 years), 57.1% (50-59), 41.2% (60-69), 65.4% (70-79), and 93.3% (≥80). Among nine variables that were significant in the univariate analysis, age, an immunocompromised status, and D-dimer levels were selected for the multivariate analysis. The multivariate analysis revealed that an advanced age (adjusted odds ratio [OR] 2.30 per 10-year increment, 95% confidence interval [CI]: 1.36-4.39), an immunocompromised status (adjusted OR 17.66, 95% CI: 3.66-145.37), and D-dimer levels (adjusted OR 1.18 per 5 μg/mL increment, 95% CI: 1.07-1.42) were independently associated with in-hospital mortality. CONCLUSIONS: In our predominantly elderly cohort, an advanced age, an immunocompromised status, and elevated D-dimer levels were independently associated with in-hospital mortality among VV-ECMO patients. Despite the high overall mortality, the present results suggest that VV-ECMO may be a reasonable therapeutic option in carefully selected elderly patients.