Impact of Age-Adjusted Charlson Comorbidity on Hospital Survival and Short-Term Outcome of Patients with Extracorporeal Cardiopulmonary Resuscitation

Abstract

Extracorporeal cardiopulmonary resuscitation (ECPR) has gradually come to be regarded as an effective therapy, but the hospital mortality rate after ECPR is still high and unpredictable. The present study tested whether age-adjusted Charlson comorbidity index (ACCI) can be used as an objective selection criterion to ensure the most efficient utilization of medical resources. Adult patients (age ≥ 18 years) receiving ECPR at our institution between 2006 and 2015 were included. Data regarding ECPR events and ACCI characteristics were collected immediately after the extracorporeal membrane oxygenation (ECMO) setup. Adverse events during hospitalization were also prospectively collected. The primary endpoint was survival to hospital discharge. The second endpoint was the short-term (2-year) follow-up outcome. A total of 461 patients included in the study were grouped into low ACCI (ACCI 0–3) (240, 52.1%) and high ACCI (ACCI 4–13) (221, 47.9%) groups. The median ACCI was 2 (interquartile range (IQR): 1–3) and 5 (IQR: 4–7) for the low and high ACCI groups, respectively. Cardiopulmonary resuscitation (CPR)-to-ECMO duration was comparable between the groups (42.1 ± 25.6 and 41.3 ± 20.7 min in the low and high ACCI groups, respectively; p = 0.754). Regarding the hospital survival rate, 256 patients (55.5%) died on ECMO support. A total of 205 patients (44.5%) were successfully weaned off ECMO, but only 138 patients (29.9%) survived to hospital discharge (32.1% and 27.6% in low and high ACCI group, p = 0.291). Multivariate logistic regression analysis revealed CPR duration before ECMO run (CPR-to-ECMO duration) and a CPR cause of septic shock to be significant risk factors for hospital survival after ECPR (p = 0.043 and 0.014, respectively), whereas age and ACCI were not (p = 0.334 and 0.164, respectively). The 2-year survival rate after hospital discharge for the 138 hospital survivors was 96% and 74% in the low and high ACCI groups, respectively (p = 0.002). High ACCI before ECPR does not predict a poor outcome of hospital survival. Therefore, ECPR should not be rejected solely due to high ACCI. However, high ACCI in hospital survivors is associated with a higher 2-year mortality rate than low ACCI, and patients with high ACCI should be closely followed up.

Keywords

• extracorporeal membrane oxygenation
• cardiopulmonary resuscitation
• extracorporeal cardiopulmonary resuscitation
• Charlson comorbidity index
• age-adjusted Charlson comorbidity index