Lactate and lactate clearance as predictors of one-year survival in extracorporeal cardiopulmonary resuscitation - An international, multicentre cohort study.

AIM: Extracorporeal cardiopulmonary resuscitation (ECPR) can be considered in selected patients with refractory cardiac arrest. Given the risk of patient futility and high resource utilisation, identifying ECPR candidates, who would benefit from this therapy, is crucial. Previous ECPR studies investigating lactate as a potential prognostic marker have been small and inconclusive. In this study, it was hypothesised that the lactate level (immediately prior to initiation of ECPR) and lactate clearance (within 24 hours after ECPR initiation) are predictors of one-year survival in a large, multicentre study cohort of ECPR patients. METHODS: Adult patients with refractory cardiac arrest at three German and four Danish tertiary cardiac care centres between 2011 and 2021 were included. Pre-ECPR lactate and 24-hour lactate clearance were divided into three equally sized tertiles. Multivariable logistic regression analyses and Kaplan-Meier analyses were used to analyse survival outcomes. RESULTS: 297 adult patients with refractory cardiac arrest were included in this study, of which 65 (22%) survived within one year. The pre-ECPR lactate level and 24-hour lactate clearance were level-dependently associated with one-year survival: OR 5.40 [95% CI 2.30-13.60] for lowest versus highest pre-ECPR lactate level and OR 0.25 [95% CI 0.09-0.68] for lowest versus highest 24-hour lactate clearance. Results were confirmed in Kaplan-Meier analyses (each p log rank < 0.001) and subgroup analyses. CONCLUSION: Pre-ECPR lactate levels and 24 hour-lactate clearance after ECPR initiation in patients with refractory cardiac arrest were level-dependently associated with one-year survival. Lactate is an easily accessible and quickly available point-of-care measurement which might be considered as an early prognostic marker when considering initiation or continuation of ECPR treatment.

Long-term survival, functional capacity and quality of life after refractory out-of-hospital cardiac arrest treated with mechanical circulatory support.

Introduction: Studies on long-term outcomes after refractory out-of-hospital cardiac arrest (OHCA) treated with mechanical circulatory support (MCS) are limited. This study aimed to evaluate long-term neurologically intact survival, functional capacity and quality of life after refractory OHCA treated with MCS. Methods: This was a follow-up study of survivors after refractory OHCA treated with MCS. Follow-up examinations comprised clinical assessment with transthoracic echocardiography and cardiopulmonary exercise test (CPX). Neurological and cognitive screening was evaluated with the Cerebral Performance Category (CPC) and Montreal Cognitive Assessment (MoCA test). A good neurological outcome was defined as CPC 1 or CPC 2. Health-related quality of life was measured by questionnaires (Short Form-36 (SF-36)). Results: A total of 101 patients with refractory OHCA were treated with MCS at Aarhus University Hospital between 2015 and 2019. The total low-flow time was median 105 min [IQR, 94-123] minutes. The hospital discharge rate was 27%. At a mean follow-up time of 4.8 years ± 1.6 (range 2.8-6.1 years), 21 patients remained alive of whom 15 consented to participate in the present study. Good neurological outcome with CPC 1-2 was found in 93% (14/15) patients. No severe cognitive function was discovered; mean MoCA score of 26.4 ± 3.1. Functional capacity examined by CPX showed acceptable VO2 max values (23.9 ± 6.3 mL/kg/min). Mean SF-36 scores revealed an overall high level of quality of life in long-term survivors. Conclusions: Long-term survival with a good neurological outcome with functional recovery was high in patients with refractory OHCA treated with MCS. These patients may expect a reasonable quality of life after discharge despite prolonged resuscitation.