Door-to-implantation time of extracorporeal life support systems predicts mortality in patients with out-of-hospital cardiac arrest.

OBJECTIVE: This study aimed to identify predictors of mortality in patients with out-of-hospital cardiac arrest (OHCA) undergoing in-hospital extracorporeal life support system (ECLS) treatment.

METHODS: We retrospectively studied the characteristics and clinical outcomes of 28 patients (January 2010 and December 2011) with OHCA and veno-arterial ECLS implemented during ongoing cardiopulmonary resuscitation (CPR) upon admission to the cath lab. Baseline left ventricular ejection fraction (LVEF) was determined after ECLS implantation and then every 24 h during and after successful weaning from ECLS.

RESULTS: Overall 30-day survival rate was 39.3 % (11 of 28 patients). Baseline characteristics, initial laboratory measurements, and LVEF on admission were not significantly different between survivors and non-survivors. There was no difference regarding median CPR duration [survivors 44.0 min (IQR 31.0-45.0) vs. non-survivors 53.0 min (IQR 40.0-61.3); P = 0.23]. Door-to-ECLS implantation time was significantly longer in non-survivors [42.5 min (IQR 28.0-56.5) vs. 25.0 min (IQR 21.0-30.0); P < 0.01]. ECLS treatment duration was not significantly different between the two groups [survivors: 4.0 days (IQR 1.5-7.5) vs. non-survivors 6.5 days (IQR 1.0-8.0); P = 0.69]. LVEF significantly improved in survivors during ECLS treatment (mean ± SD survivor 47.5 ± 14.7 % vs. non-survivor 23.3 ± 14.9 %; P < 0.01). The door-to-ECLS implantation time was the only significant and independent predictor of 30-day mortality in multivariate Cox regression analysis (P = 0.04). Kaplan-Meier survival analysis showed a benefit favouring patients with a door-to-ECLS implantation time <30 min (log rank 6.29; P = 0.01).

CONCLUSION: A door-to-ECLS implantation time <30 min significantly improves 30-day outcomes in patients with OHCA.