Short-term and longer-term survival after veno-arterial extracorporeal membrane oxygenation in an adult patient population: does older age matter?

Background: Veno-arterial (V-A) extracorporeal membrane oxygenation (ECMO) is increasingly being used for patients with refractory cardiopulmonary failure. This study evaluates the short-term (to discharge) and longer-term (1 year) survival among older (⩾65 years) versus younger (<65 years) adults, adjusted for comorbidities, in a diverse cohort of V-A ECMO patients.

Methods: This was a retrospective cohort analysis of 131 adult patients (28% ⩾65 years old) who received V-A ECMO at an academic medical center from 2004-2013. Demographics, comorbidities and surgical characteristics were abstracted from the medical records and verified. Mortality status at discharge and at one year post-ECMO were determined by the hospital clinical information system, updated monthly with Social Security Death Index data. Cox proportional hazard analyses were conducted to evaluate associations between age strata and mortality at discharge and at one year post ECMO initiation, adjusted for covariates.

Results: The survival rate following V-A ECMO was 48% (n=68/131) to discharge and 44% (n=58/131) to one year. Age ⩾65 versus <65 was significantly associated with increased mortality during hospitalization (HR:2.03; 95%CI=1.23-3.33) and at one year (HR:1.81; 95% CI=1.12-2.93); these associations were attenuated and did not retain statistical significance after adjustment for comorbidities (HR:1.61; 95%CI=0.90-2.88 and HR:1.42; 95% CI=0.81-2.50, respectively). Statistically significant predictors of mortality at discharge and one year included history of coronary artery bypass graft, peripheral vascular disease and renal failure/dialysis (p<0.05).

Conclusions: Older age was not independently associated with short-term or longer-term survival among V-A ECMO patients, but may reflect greater comorbidity, suggesting that age alone may not disqualify patients from V-A ECMO therapy.