Impact of a Modified Institutional Protocol on Outcomes After Extracorporeal Cardiopulmonary Resuscitation for Refractory Out-Of-Hospital Cardiac Arrest

Favorable resuscitation characteristics in patients undergoing extracorporeal cardiopulmonary resuscitation: A secondary analysis of the INCEPTION-trial

Introduction

Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly used as a supportive treatment for refractory out-of-hospital cardiac arrest (OHCA). Still, there is a paucity of data evaluating favorable and unfavorable prognostic characteristics in patients considered for ECPR.

Methods

We performed a previously unplanned post-hoc analysis of the multicenter randomized controlled INCEPTION-trial. The study group consisted of patients receiving ECPR, irrespective of initial group randomization. The patients were divided into favorable survivors (cerebral performance category [CPC] 1-2) and unfavorable or non-survivors (CPC 3-5).

Results

In the initial INCEPTION-trial, 134 patients were randomized. ECPR treatment was started in 46 (66%) of 70 patients in the ECPR treatment arm and 3 (4%) of 74 patients in the conventional treatment arm. No statistically significant differences in baseline characteristics, medical history, or causes of arrest were observed between survivors (n = 5) and non-survivors (n = 44). More patients in the surviving group had a shockable rhythm at the time of cannulation (60% vs. 14%, p = 0.037), underwent more defibrillation attempts (13 vs. 6, p = 0.002), and received higher dosages of amiodarone (450 mg vs 375 mg, p = 0.047) despite similar durations of resuscitation maneuvers. Furthermore, non-survivors more frequently had post-ECPR implantation adverse events.

Conclusion

The persistence of ventricular arrhythmia is a favorable prognostic factor in patients with refractory OHCA undergoing an ECPR-based treatment. Future studies are warranted to confirm this finding and to establish additional prognostic factors.Clinical trial Registration:clinicaltrials.gov registration number NCT03101787.

Impact of clinical variables on outcomes in refractory cardiac arrest patients undergoing extracorporeal cardiopulmonary resuscitation

Background

In the past two decades, extracorporeal resuscitation (ECPR) has been increasingly used in the management of refractory cardiac arrest (CA) patients. Decision algorithms have been used to guide the care such patients, but the effectiveness of such decision-making tools is not well described. The aim of this study was to compare the rate of survival with a good neurologic outcome of patients treated with ECPR meeting all criteria of a clinical decision-making tool for the initiation of ECPR to those for whom ECPR was implemented outside of the algorithm.

Methods

All patients who underwent E-CPR between January 2014 and December 2021 at the Montreal Heart Institute were included in this retrospective analysis. We dichotomized the cohort according to adherence or non-adherence with the ECPR decision-making tool, which included the following criteria: age ≤65 years, initial shockable rhythm, no-flow time <5 min, serum lactate <13 mmol/L. Patients were included in the "IN" group when they met all criteria of the decision-making tool and in the "OUT" group when at least one criterion was not met.

Main outcomes and measures

The primary outcome was survival with intact neurological status at 30 days, defined by a Cerebral Performance Category (CPC) Scale 1 and 2.

Results

A total of 41 patients (IN group, n = 11; OUT group, n = 30) were included. A total of 4 (36%) patients met the primary outcome in the IN group and 7 (23%) in the OUT group [odds ratio (OR): 1.88 (95% CI, 0.42-8.34); P = 0.45]. However, survival with a favorable outcome decreased steadily with 2 or more deviations from the decision-making tool [2 deviations: 1 (11%); 3 deviations: 0 (0%)].

Conclusion and relevance

Most patients supported with ECPR fell outside of the criteria encompassed in a clinical decision-making tool, which highlights the challenge of optimal selection of ECPR candidates. Survival rate with a good neurologic outcome did not differ between the IN and OUT groups. However, survival with favorable outcome decreased steadily after one deviation from the decision-making tool. More studies are needed to help select proper candidates with refractory CA patients for ECPR.

Early extracorporeal CPR for refractory out-of-hospital cardiac arrest - A pre-planned per-protocol analysis of the INCEPTION-trial

BACKGROUND

Evidence for extracorporeal cardiopulmonary resuscitation (CPR) in refractory out-of-hospital cardiac arrest (OHCA) remains inconclusive. Recently, the INCEPTION-trial, comparing extracorporeal with conventional CPR, found no statistically significant difference in neurologically favorable survival. Since protocol deviations were anticipated, a pre-specified per-protocol analysis was foreseen.

METHODS

The per-protocol analysis of the INCEPTION trial excluded patients not meeting inclusion or exclusion criteria, amongst which time-to-cannulation of >60 minutes, and achieving a return of spontaneous circulation before hospital arrival. Crossovers were excluded as well. The primary outcome (30-day survival in a neurologically favorable condition; cerebral performance category [CPC] 1-2) was primarily analyzed under a frequentist statistical framework. In addition, Bayesian analysis under a minimally informative prior was performed.

RESULTS

Eighty-one patients were included in the per-protocol analysis (extracorporeal CPR n = 33, conventional CPR n = 48). Thirty-day survival with CPC1-2 was 15% in the extracorporeal CPR group versus 9% in the conventional CPR group (adjusted OR 1.9; 95% CI 0.4-9.3; p-value 0.393). Bayesian analysis showed an 84% posterior probability of any ECPR benefit and a 61% posterior probability of a 5% absolute risk reduction for the primary outcome.

CONCLUSION

A pre-planned, pre-specified per-protocol analysis of the INCEPTION-trial, found a higher survival with favorable neurological in patients undergoing ECPR versus CCPR for refractory shockable OHCA. This difference did not reach statistical significance, but results should be interpreted with care, in the light of the small remaining sample size.

Extracorporeal cardiopulmonary resuscitation in out-of-hospital cardiac arrest - current status

PURPOSE OF REVIEW

Extracorporeal cardiopulmonary resuscitation (ECPR) is an emerging treatment for refractory cardiac arrest. In recent years, several randomized controlled trials have been published that aimed to address the efficacy and effectiveness of ECPR for out-of-hospital cardiac arrest (OHCA). Despite the lack of high-quality evidence concerning clinical effectiveness and cost-effectiveness, ECPR is increasingly implemented throughout the world. In this review, we aim to provide an overview of the current status of ECPR for OHCA.

RECENT FINDINGS

Randomized controlled trials showed diverging results, largely due to differences in selection criteria and study design. Single-center studies, performed in centers with extraordinary expertise and dedication consistently achieve a low-flow time of around 60 min, but such achievements are rarely reproduced outside these centers. Strict patient selection can improve outcome but simultaneously limits the caseload. Preliminary data suggest that outcome may also be improved by avoiding hyperoxia postresuscitation.

SUMMARY

The potential of ECPR to increase survival in selected patients in highly dedicated systems seems to be proven, the question remains whether ECPR for OHCA can be widely implemented successfully and can develop into a sustainable, commonplace resource-effective treatment.

Prognostic factors associated with favourable functional outcome among adult patients requiring extracorporeal cardiopulmonary resuscitation for out-of-hospital cardiac arrest: A systematic review and meta-analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR), has demonstrated promise in the management of refractory out-of-hospital cardiac arrest (OHCA). However, evidence from observational studies and clinical trials are conflicting and the factors influencing outcome have not been well established.

METHODS

We conducted a systematic review and meta-analysis summarizing the association between pre-ECPR prognostic factors and likelihood of good functional outcome among adult patients requiring ECPR for OHCA. We searched Medline and Embase databases from inception to February 28, 2023 and screened studies with two independent reviewers. We performed meta-analyses of unadjusted and adjusted odds ratios, adjusted hazard ratios and mean differences separately. We assessed risk of bias using the QUIPS tool and certainty of evidence using the GRADE approach.

FINDINGS

We included 29 observational and randomized studies involving 7,397 patients. Factors with moderate or high certainty of association with increased survival with favourable functional outcome include pre-arrest patient factors, such as younger age (odds ratio (OR) 2.13, 95% CI 1.52 to 2.99) and female sex (OR 1.37, 95% CI 1.11 to 1.70), as well as intra-arrest factors, such as shockable rhythm (OR 2.79, 95% CI 2.04 to 3.80), witnessed arrest (OR 1.68 (95% CI 1.16 to 2.42), bystander CPR (OR 1.55, 95% CI 1.19 to 2.01), return of spontaneous circulation (OR 2.81, 95% CI 2.19 to 3.61) and shorter time to cannulation (OR 1.14, 95% CI 1.17 to 1.69 per 10 minutes).

INTERPRETATION

The findings of this review confirm several clinical concepts wellestablished in the cardiac arrest literature and their applicability to the patient for whom ECPR is considered - that is, the impact of pre-existing patient factors, the benefit of timely and effective CPR, as well as the prognostic importance of minimizing low-flow time. We advocate for the thoughtful consideration of these prognostic factors as part of a risk stratification framework when evaluating a patient's potential candidacy for ECPR.

Lower Limb Ischemia in Surgical Femoral Veno-Arterial Extracorporeal Membrane Oxygenation

OBJECTIVES

To analyze the incidence, clinical impact on survival, and risk factors of lower limb ischemia (LLI) of surgical peripheral femoral venoarterial extracorporeal membrane oxygenation (VA ECMO) in the current era.

DESIGN

A retrospective analysis of the authors' institutional database of VA ECMO was performed. Patients were divided into 2 groups according to the occurrence of LLI. The primary endpoint was survival to hospital discharge. Risk factors of LLI were searched with multivariate analyses.

SETTING

University hospital.

PARTICIPANTS

Adult patients receiving peripheral VA ECMO for refractory cardiogenic shock and cardiac arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From January 2018 to December 2021, 188 patients (mean age: 52.0 ± 14.1 years; 63.8% male, 36.2% female) received peripheral VA ECMO. Male sex was more prevalent in the group without LLI (65.9% v 33.3%; p = 0.031). Twelve (6.4%) patients developed LLI during VA ECMO support (n = 6) or after VA ECMO removal (n = 6). Survival to hospital discharge was not statistically different between patients with and without LLI (50.0% v 48.3%; p = 0.571). Female sex patients were at increased risk for LLI (odds ratio 4.38, 95% CI 1.21-15.81; p = 0.024).

CONCLUSIONS

Peripheral femoral VA ECMO through a surgical approach is associated with a low LLI rate, which does not increase the risk of in-hospital mortality. The female sex is an independent risk factor for LLI.

Time-saving effect of real-time ultrasound-guided cannulation for extracorporeal cardiopulmonary resuscitation: A multicenter retrospective cohort study

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR), a bridge to treatments for cardiac arrest patients, can be technically challenging and requires expertise. While ultrasound guidance is frequently used for vascular access, its effects on cannulation time in patients treated with ECPR are poorly defined. We hypothesized that real-time ultrasound guidance would contribute to faster and safer cannulation for ECPR.

METHODS

This nationwide, multicenter, retrospective study analyzed data from 36 Japanese institutions. Patients who were over age 18 years and underwent ECPR between January 1, 2013, and December 31, 2018, were included. Patients who underwent open surgical vascular access were excluded. Cannulation time and outcomes of patients who underwent real-time ultrasound-guided cannulation (i.e., ultrasound-guided group) were compared to those cannulated without the use of real-time ultrasound guidance (control group) using propensity score matching analysis.

RESULTS

The ultrasound-guided group comprised 510 cases, whereas the control group comprised 941 cases. Of those, 443 propensity score-matched pairs were evaluated. Cannulation time in the ultrasound-guided group was 2.5 minutes shorter than in the control group [difference, -2.5 minutes; 95% Confidence interval (CI), -3.7 to -1.3, p < 0.001]. The incidence of catheter-related complications and the incidence of the poor neurological outcomes (Cerebral Performance Category ≥3) did not differ between groups [Odds ratio (OR), 1.51; 95% CI, 0.64-3.74; OR, 1.08; 95% CI, 0.83-1.59].

CONCLUSION

Real-time ultrasound-guided cannulation was associated with shorter cannulation time of ECPR.

Benefits, key protocol components, and considerations for successful implementation of extracorporeal cardiopulmonary resuscitation: a review of the recent literature

The application of venoarterial extracorporeal membrane oxygenation (ECMO) in patients unresponsive to conventional cardiopulmonary resuscitation (CPR) has significantly increased in recent years. To date, three published randomized trials have investigated the use of extracorporeal CPR (ECPR) in adults with refractory out-of-hospital cardiac arrest. Although these trials reported inconsistent results, they suggest that ECPR may have a significant survival benefit over conventional CPR in selected patients only when performed with strict protocol adherence in experienced emergency medical services-hospital systems. Several studies suggest that identifying suitable ECPR candidates and reducing the time from cardiac arrest to ECMO initiation are key to successful outcomes. Prehospital ECPR or the rendezvous approach may allow more patients to receive ECPR within acceptable timeframes than ECPR initiation on arrival at a capable hospital. ECPR is only one part of the system of care for resuscitation of cardiac arrest victims. Optimizing the chain of survival is critical to improving outcomes of patients receiving ECPR. Further studies are needed to find the optimal strategy for the use of ECPR.