The differential neurologic prognosis of low-flow time according to the initial rhythm in patients who undergo extracorporeal cardiopulmonary resuscitation

Journal Pre-proof The Differential neurologic prognosis of low-flow time according to the initial rhythm in patients who undergo extracorporeal cardiopulmonary resuscitation Ryoung-Eun Ko, Jeong-Am Ryu, Yang Hyun Cho, Kiick Sung, Kyeongman Jeon, Gee Young Suh, Taek Kyu Park, Joo Myung Lee, Young Bin Song, Joo-Yong Hahn, Jin-Ho Choi, Seung-Hyuk Choi, Hyeon-Cheol Gwon, Keumhee C. Carriere, Joonghyun Ahn, Jeong Hoon Yang

PII:

S0300-9572(20)30037-X

DOI:

https://doi.org/10.1016/j.resuscitation.2020.01.015

Reference:

RESUS 8378

To appear in:

Resuscitation

Received Date:

27 September 2019

Revised Date:

25 December 2019

Accepted Date:

10 January 2020

Please cite this article as: Ko R-Eun, Ryu J-Am, Cho YH, Sung K, Jeon K, Suh GY, Park TK, Lee JM, Song YB, Hahn J-Yong, Choi J-Ho, Choi S-Hyuk, Gwon H-Cheol, Carriere KC, Ahn J, Yang JH, The Differential neurologic prognosis of low-flow time according to the initial rhythm in patients who undergo extracorporeal cardiopulmonary resuscitation, Resuscitation (2020), doi: https://doi.org/10.1016/j.resuscitation.2020.01.015

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2019 Published by Elsevier.

The Differential neurologic prognosis of low-flow time according to the initial rhythm in patients who undergo extracorporeal cardiopulmonary resuscitation

Ryoung-Eun Ko, MDa, Jeong-Am Ryu, MDa, Yang Hyun Cho, MDb, Kiick Sung, MDb, Kyeongman Jeon, MDa,c, Gee Young Suh, MDa,c, Taek Kyu Park, MDd, Joo Myung Lee,

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MDd, Young Bin Song, MDd, Joo-Yong Hahn, MDd, Jin-Ho Choi, MDd, Seung-Hyuk Choi, MDd, Hyeon-Cheol Gwon, MDd, Keumhee C. Carriere, PhDe,f, Joonghyun Ahn, MSe, Jeong

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Hoon Yang, MDa,d

Department of Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University

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School of Medicine, Seoul, Republic of Korea; bDepartment of Thoracic and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul,

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Republic of Korea; cDivision of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul,

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Korea; dDivision of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea; eBiostatistics and

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Clinical Epidemiology Center, Samsung Medical Center, Seoul, Korea; fDepartment of

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Mathematical and Statistical Sciences, University of Alberta, Edmonton, Canada.

Corresponding author: Jeong Hoon Yang, MD, Ph.D Department of Critical Care Medicine and Division of Cardiology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Korea. 1

Tel: 82-2-3410-1768 E-mail: [email protected]

Running title: Arrest rhythm and outcome in ECPR

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Abstract Background: Limited data is available on the association between low-flow time and neurologic outcome according to the initial arrest rhythm in patients underwent extracorporeal cardiopulmonary resuscitation (ECPR). Methods: Between September 2004 and December 2018, 294 patients with in-hospital cardiac arrest (IHCA) were included in this analysis. We classified the patients into asystole

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(n = 42), pulseless electrical activity (PEA, n = 163) and shockable rhythm (n = 89) according to their initial rhythm. Primary outcome was poor neurologic outcome defined as Cerebral Performance Categories scores of 3, 4, and 5.

Results: One-hundred ninety IHCA patients (64.6%) had poor neurologic outcomes. There

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was significantly worse neurologic outcomes among IHCA patients according to their initial

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rhythm (asystole [88.1%], PEA [66.3%], and shockable rhythm [50.6%], p < 0.001). The PEA group and the shockable rhythm group showed a significant association between low-

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flow time and neurologic outcomes while this relationship was not observed in the asystole group: PEA [ρ = 0.224, p = 0.005], shockable rhythm [ρ = 0.298, p = 0.006]), and asystole [ρ

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= - 0.091, p = 0.590]. The best discriminative CPR to pump-on time for neurologic outcome was 22 minutes in the PEA group (area under the curve 0.687, 95% confidence interval [CI]

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0.610 – 0.758, p < 0.001) and 46 minutes in the shockable rhythm group (area under the curve 0.671, 95% CI 0.593 – 0.743, p < 0.001).

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Conclusions: The effect of interplay between arrest rhythm and low-flow time might be helpful for decisions about team activation and management for ECPR and could provide information for early neurologic prognosis.

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Abbreviations CCPR = Conventional cardiopulmonary resuscitation CPC = Cerebral Performance Categories CPR = Cardiopulmonary resuscitation ECMO = Extracorporeal membrane oxygenation

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ECPR = Extracorporeal cardiopulmonary resuscitation IHCA = In-hospital cardiac arrest OHCA = Out of hospital cardiac arrest PEA = Pulseless electrical activity

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ROSC = Return of spontaneous circulation

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TTM = Targeted temperature management

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Keywords: Cardiopulmonary arrest, extracorporeal membrane oxygenator, arrest rhythm

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Introduction

Veno-arterial extracorporeal membrane oxygenation (ECMO) is widely used for refractory cardiogenic shock, and the American Heart Association recommends the implementation of extracorporeal cardiopulmonary resuscitation (ECPR) as an alternative method for patients with reversible causes of cardiac arrest after conventional cardiopulmonary resuscitation

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(CCPR) for more than 10 minutes without return of spontaneous circulation (ROSC).1 Recently, the use of ECPR has increased, resulting in better neurological and survival

outcomes compared to CCPR.2,3 In addition, extracorporeal cardiopulmonary resuscitation has been found to be more effective in in-hospital cardiac arrest (IHCA) than in out of

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hospital cardiac arrest (OHCA) with favorable outcomes.2-4

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In CCPR, the initial arrest rhythm has been a well-known as an important prognostic factor for successful resuscitation. Previous studies have shown better survival rate in

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shockable rhythm (ventricular tachycardia and ventricular fibrillation) compared to nonshockable rhythms such as pulseless electrical activity (PEA) and asystole.5,6 Shockable

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rhythms tend to have shorter low-flow time, are more likely to have a reversible etiology of cardiac arrest, and result in better clinical outcomes in patients undergoing CCPR.7,8

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However, in the setting of ECPR, the impact of initial arrest rhythm on neurologic outcomes has not yet been fully elucidated.

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Therefore, we investigated the association of initial arrest rhythm, low-flow time, and

neurologic outcomes for IHCA patients who underwent ECPR.

Materials and methods

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Study population

This was a retrospective, single-center, observational study of adult patients who underwent ECPR for IHCA at the Samsung Medical Center between September 2004 and December 2018. This study was approved by the Institutional Review Board (IRB) of Samsung Medical Center (IRB no. 2019-05-002). The requirement for informed consent was waived due to the

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retrospective nature of the study. Clinical and laboratory data was collected by a trained study coordinator using a standardized case report form. All consecutive patients older than 18

years of age who underwent ECPR were screened for inclusion in this study. Patients who received ECPR due to out-of hospital cardiac arrest or failed ECMO cannulation were

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excluded. A total of 294 IHCA patients who were resuscitated by veno-arterial ECMO were

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analyzed in this study (Fig. 1).

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Definitions and outcomes

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ECPR was defined as successful veno-arterial ECMO implantation and pump-on with chest compression for external cardiac massage during the index procedure in patients with cardiac

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arrest. When ROSC occurs during ECMO cannulation, practitioners typically do not remove the inserted cannula or stop the ECMO pump-on process.2,9 ECMO pump-on was defined as

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the status of stopped chest compression following successful ECMO implantation and activation. At this time, the ECMO flow was gradually increased until respiratory and hemodynamic statuses were stable. Cardiopulmonary resuscitation (CPR) to ECMO pump-on time was defined as the time from the initiation of chest compressions to the time at which the ECMO pump was turned on. As for recurrent arrest cases, if the duration of ROSC was 6

sustained for more than 20 minutes, we made the following arrest event a standard initial point of cardiac massage. The ROSC before ECMO pump-on defined as an event that ROSC occurred during CPR and did not last for 20 minutes.10 The initial rhythm was defined as the initial identified cardiac rhythm. The primary outcome was neurological status upon discharge from the hospital, as assessed by the Glasgow Pittsburgh Cerebral Performance Categories (CPC) scale (ranging from 1 to 5).11 CPC scores of 1 and 2 were classified as good neurological outcomes; CPC scores of 3,4, and 5 were considered poor neurological

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outcomes.12

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Procedure

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The resuscitation procedure was performed in the same way as described in our previous study.13-15 Cases in which ECPR was deferred included a short life expectancy (< 6 months),

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terminal malignancy, unwitnessed collapse, limited physical activity, poor oxygenation and ventilation during ACLS, or CPR undertaken for longer than 60 minutes at the time of initial

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contact. Age alone did not constitute a contraindication to ECPR.16 Targeted temperature management (TTM) was performed using surface cooling devices.

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We used a commercial temperature regulation system consisting of a hydrogel pad (Arctic Sun@; Medivance Corp, Louisville, CO, USA). Intensivists in each intensive care unit

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determined TTM. Surface cooling and the degree of targeted temperature were determined by each intensivist in the intensive care unit according to the Samsung Medical Center therapeutic hypothermia protocol.17

Statistical analysis 7

All data is presented as medians and interquartile range for continuous variables, and as numbers and percentages for categorical variables. Continuous and categorical variables were analyzed by one-way analysis of variance and Pearson’s chi-square or Fisher’s exact tests, respectively, to determine whether there were differences in characteristics among the three groups according to initial rhythm. If a difference was observed, post-hoc analysis was

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performed to determine which groups were different. The primary outcome was poor neurological outcome in association with CPR to pump-on time. Initially, we built a common multivariable logistic regression model considering all three rhythms with an interaction

term, along with all available clinical and demographic variables. However, our sample size

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seemed too small to have enough power to detect significant interaction effects. We therefore

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proceeded with modeling for each rhythm separately via the stepwise manner to identify relevant predictors of the primary outcomes. The model’s goodness was checked via the

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Hosmer-Lemeshow test and obtained the C-index. Next, we estimated the predicted proportion of poor neurologic outcome from each model for each rhythm, and associated

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them with CPR to pump-on time on a logarithmic scale. We first drew scatter plots with a spline curve inserted and obtained the Pearson’s correlation coefficients. We also obtained the

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confidence interval (CI) for the correlation. The optimal cut-off values for CPR to pump-on time for predicting poor neurologic outcome were determined by a receiver-operating

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characteristics curve and the Youden Index.18 All tests were two-sided, and p values <0.05 were considered statistically significant. All

data analyses were performed using R Statistical Software. (Version 3.2.5; R Foundation for Statistical Computing, Vienna, Austria).

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Results

Baseline and procedural characteristics

Of the 294 IHCA patients who underwent ECPR, 42 patients (14.3%) had asystole, 163 patients (55.4%) had PEA, and 89 patients (30.3%) had shockable rhythm. All patients were

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bystander-witnessed cardiac arrest. The baseline characteristics of the three groups are presented in Table 1. The median patient age was 63.0 [54.0 – 73.0] and 198 (67.3%) patients were men. There were no significant differences among the three groups aside from age and

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sex; the PEA group was older compared to the other two groups, and the shockable rhythm group had a greater proportion of men than the other groups.

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The characteristics of cardiac arrest and procedures are shown in Table 2. Ischemic heart disease was the most common cause of cardiac arrest among 146 patients (49.7%) and 66

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patients (45.2%) were ST-segment elevation myocardial infarction. The median time from CPR to ECMO pump-on was 30.0 minutes [19.0 – 47.0] and 113 patients (38.4%) had ROSC

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before ECMO pump-on. The median duration of ROSC was 5.0 (1.0 – 11.0) minutes. The common locations of insertion were intensive care units (n = 155, [52.7%]) followed by a

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catheterization laboratory (n = 93, [31.6%]). There were no significant differences in TTM

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and post ECPR management among the three groups.

Neurological and clinical outcomes

In-hospital mortality rate was 56.1% (165 patients). Hospital mortality was significantly different among IHCA patients according to initial rhythm (asystole [81.0%], PEA [57.1%], 9

and shockable rhythm [42.7%], p < 0.001, Fig. 2). Poor neurologic outcomes were also significantly different among IHCA patients according to initial rhythm (asystole [88.1%], PEA [66.3%], and shockable rhythm [50.6%], p < 0.001, Fig. 2).

Relationship between low-flow time and neurologic outcomes according to initial rhythm

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For each rhythm group, the multivariable logistic regression model was attempted. For the asystole group, there were no significant predictors, and the small amount of poor neurologic outcome may affect results. In the PEA group, poor neurologic outcome was adjusted by age, procedures associated with ECMO, continuous renal replacement therapy, hemoglobin before

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ECMO and the multivariable logistic model had a C-index of 0.802. For the shockable

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rhythm group, the poor neurologic outcome was significantly associated with dyslipidemia, ischemic cause, total bilirubin, creatinine, and serum glucose, and the model had a C-index of

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0.854. We obtained the predicted proportion of poor neurologic outcome, adjusted by the significant predictors for each group. The locally weighted scatterplot smoothing technique

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created a smooth line through the scatter plot, suggesting a linear relationship. The PEA group and the shockable rhythm group showed associations between low-flow time and

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neurologic outcomes. Low flow time was correlated with poor neurologic outcomes in the PEA and shockable rhythm groups, but not the asystole group. Furthermore, the PEA group

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has a limited time to rescue the neurologic prognosis compared to the shockable rhythm group. The level of association was highly significant with the Pearson’s correlation of 0.224 (95% CI 0.067 – 0.370, p = 0.005) and 0.298 (95% CI 0.088 – 0.483, p = 0.006) for the PEA group and the shockable rhythm group, respectively. This relationship was not observed in the asystole group by with the Pearson’s correlation of -0.091 (95% CI -0.403 – 0.240, p = 10

0.590). The receiver-operating characteristics curve analysis was used to assess the best cut-off for CPR to pump-on time for a good neurologic outcome in the PEA and shockable rhythm groups. The best discriminative CPR to pump-on time for good neurologic outcome was 22 minutes in the PEA group (area under the curve 0.687, 95% CI 0.610 – 0.758, p < 0.001) and 46 minutes in the shockable rhythm group (area under the curve 0.671, 95% CI 0.593 –

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0.743, p < 0.001).

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Discussion

In the present study, we evaluated the impact of initial arrest rhythm on clinical outcomes in

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IHCA patients undergoing ECPR and investigated whether neurological outcome was associated with low-flow time according to the initial rhythm. The major findings of this

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study were as follows: (1) Neurologic outcomes differed significantly according to initial rhythm in IHCA patients, in the order of shockable rhythm, PEA, and asystole being poorest.

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(2) Prolonged low-flow time was significantly associated with poorer neurologic outcomes in patients with shockable rhythm and PEA but this relationship was not observed in those with

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asystole. (3) The cut-off value of low-flow time for good neurologic outcomes in patients with shockable rhythm was longer than that of the PEA group.

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Several previous studies have shown that no flow or low-flow time is one of the most

important predictors of overall outcomes after ECPR along with age, initial shockable rhythm, pulse pressure, lactate level, and Sequential Organ Failure Assessment score.4,16,19 Unlike other prognostic factors, low-flow time represented by CPR to pump-on time is a unique modifiable prognostic factor. Considering findings from previous studies in 11

conjunction with this study, improved survival and neurologic outcomes can be achieved when patients receive the ECMO pump-on as soon as possible.16,19-21 However, given that ECPR is a labor-intensive procedure with limited resources, it is not easy to reduce CPR to pump-on time without a well-organized ECMO team. Thus, hospital-specific ECPR programs should be required for ECMO team activation after only 10 minutes of CCPR as recommended by the American Heart Association.1

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Several studies have evaluated CPR outcomes according to initial rhythm.22-24 In these studies, shockable rhythm demonstrated better outcomes than PEA, and asystole was the

worst. Also, similar results were observed in patients who underwent ECPR.25 This study also demonstrated the poorness of neurologic and mortality outcomes in the descending order of

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shockable rhythm, PEA, and asystole. The majority of IHCAs are due to PEA or

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asystole.22,26,27 While shockable rhythm is often due to cardiac etiologies, PEA and asystole have a multifactorial etiology.22,26,28 Many programs exclude patients with asystole and PEA

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from consideration of ECPR due to poor outcomes after CCPR.22,29,30 However, the causes of PEA are various and include reversible diseases such as hypovolemia, pulmonary embolism,

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tension pneumothorax, and electrolyte abnormalities.31,32 These reversible diseases might be better diagnosed and treated through use of ECPR.

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In this study, the interplay between low-flow time and neurological outcomes according to the initial rhythm. The PEA and shockable rhythm groups showed poor neurologic

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outcomes associated with prolonged CPR to pump-on time. Conversely, the asystole group showed poor neurologic outcomes regardless of CPR to pump-on time. It is uncertain why no relationship was found between low-flow time and neurologic outcomes in patients with asystole. Therefore, the application of ECPR should be carefully considered in patients with asystole as an initial rhythm. Meanwhile, for patients with PEA in our study, low-flow time 12

was associated with better neurologic prognosis although its cut-off value was shorter than that for patients with shockable rhythm. These findings suggest that good neurologic outcomes would be expected in patients with PEA undergoing efficient ECPR where short CPR to pump-on time could be achieved. The neurological benefits of shockable rhythm is maximized with shorter CPR to pump on time and minimized with longer CPR to pump on time. This proportional relationship was

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also observed in PEA. Shockable rhythm is well known as a good prognostic factor in IHCA. Our result also showed that shockable rhythm have better survival and neurologic outcomes. It may be due to more likely to have ROSC before ECMO pump-on although there was no

statistically significance (26.2%, 37.4%, and 46.1%, P = 0.085) in shockable rhythm. If there

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is a reversible cause in shockable rhythm, aggressive ECPR may improve the neurological

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outcomes of IHCA patients.

There are several limitations to our study that should be considered. First, because it was

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conducted as a retrospective cohort study in a single center, there is always the possibility of selection bias influencing the significance of our findings. However, the data were

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prospectively collected from all patients consecutively underwent ECPR. Thus, our cohort is more likely to reflect the patients encountered in routine ECPR practice, and our findings

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could therefore be readily applicable in similar settings. Second, this was a retrospective observational cohort study thus, the CPC score was determined based on medical records. By

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using two independent neurologists’ agreement on the score, any bias may have been ameliorated to some extent. Third, this study was conducted over a long period of time at a single institution. During this time, there were significant changes in post-arrest management, which may have affected patient outcomes during the study period. However, there was no change in the definition of CPC score. Fourth, withdrawal of care may have been a 13

confounding factor in evaluating neurological prognosis in ECPR patients. Fifth, several variables such as thyroid hormone and electrolytes that can affect the outcome might be missed for the analysis due to the nature of retrospective study.

Conclusions In IHCA patients who underwent ECPR, low-flow time in PEA and shockable rhythm

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patients as an initial arrest rhythm was associated with neurologic outcomes but not in

asystole patients. Therefore, the effect of interplay between arrest rhythm and low-flow time might be helpful for making decisions about team activation and management of ECPR and

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could provide useful information on early neurologic prognosis. Authors’ contribution

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REK conceived and designed the study, analyzed the data and drafted this manuscript. JAR,

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THC, KS, KJ, GYS, TKP, JML, YBS, JYH, JHC, SHC, HCG, KC, and JA contributed to the design of this study, analysis of the data, and writing of the manuscript. JHY conceived and designed the study, analyzed the data, and wrote the final manuscript. All authors have read

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Declarations:

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and approved the final manuscript.

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Ethics approval and consent to participate The study protocol was approved by local Ethics Committees and informed consent was waived because of the retrospective nature of the study.

Consent for publication Not applicable. 14

Availability of data and materials The datasets used and/or analyzed during the current study are available form the corresponding author on reasonable request.

The authors declare that they have no competing interests.

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Conflicts of Interest: None to declare

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None to declare.

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Acknowledgement

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Funding No funding was obtained for this study.

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Competing interests

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Figure Legends

Fig. 1 - Study flow chart. CPR, cardiopulmonary resuscitation; ECMO, extracorporeal

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membrane oxygenation; ECPR, extracorporeal cardiopulmonary resuscitation.

Fig. 2 - Neurological outcome among IHCA patients according to initial rhythm. IHCA, inhospital cardiac arrest; PEA, pulseless electrical activity. The variables included in modeling are as follows; gender, log transformed age, log 21

transformed BMI, malignancy, diabetes, hypertension, dyslipidemia, smoking history, chronic kidney disease, peripheral arterial occlusion disease, history of cerebral vascular disease, history of myocardial infarction, history of PCI, history of CABG, history of heart transplantation, percutaneous insertion, venting, distal perfusion, ischemic cause, log transformed ECMO duration, continuous renal replacement therapy at admission day, vasopressor at admission day, IABP, mechanical ventilation at admission day, therapeutic

Jo

ur

na

lP

re

-p

total bilirubin, creatinine, and log transformed max glucose.

ro of

temperature management, defibrillation, ROSC before ECMO pump-on, pre-hemoglobin,

Fig. 3 - Relationship between low-flow time and neurologic outcomes according to initial 22

rhythm (Black: asystole, Red: PEA, and Blue: shockable rhythm). PEA, pulseless electrical

Jo

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na

lP

re

-p

ro of

activity.

23

Variables

Asystole (n = 42)

PEA (n = 163)

Age (yr)

62.5 [47.0 - 74.0]

Sex, male

24 (57.1)

BMI (kg/m2)

25.3 [20.8 - 28.3]

Current smoker

13 (31.0)

p value

67.0 [56.5 - 75.0]

59.0 [51.0 - 68.0]

0.001*,**

102 (62.6)

72 (80.9)

0.004**,***

24.1 [21.5 - 26.7]

23.4 [21.1 - 25.3]

0.113

26 (16.0)

20 (22.7)

0.074

pr

oo

Shockable rhythm (n = 89)

e-

Pr

Medical history

f

Table 1 - Baseline characteristics of study patients and laboratory results stratified by initial rhythm at ECPR

13 (31.0)

55 (33.7)

34 (38.2)

0.668

Hypertension

17 (40.5)

83 (50.9)

41 (46.1)

0.440

Malignancy

6 (14.3)

24 (14.7)

14 (15.7)

0.969

4 (9.5)

23 (14.1)

16 (18.0)

0.425

7 (16.7)

23 (14.1)

15 (16.9)

0.817

5 (11.9)

30 (18.4)

23 (25.8)

0.142

Cerebral vascular disease

6 (14.3)

17 (10.4)

15 (16.9)

0.334

History of PCI

5 (11.9)

31 (19.0)

25 (28.1)

0.074

History of CABG

0 (0.0)

10 (6.1)

5 (5.6)

0.264

History of heart transplantation

3 (7.1)

4 (2.5)

3 (3.4)

0.327

9.5 [5.4 - 14.2]

8.1 [4.3 - 11.6]

7.4 [3.3 - 11.8]

0.268

Dyslipidemia Chronic kidney diseasea

na l

Diabetes mellitus

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Previous myocardial infarction

Laboratory data on admission Initial lactate (mmol/L)

24

312.5 [218.0 - 418.0]

298.0 [225.0 - 373.0]

295.0 [249.0 - 363.0]

0.932

Hemoglobin before ECMO (g/dL)

10.5 [8.9 - 12.0]

10.9 [9.5 - 12.9]

11.6 [9.9 - 13.8]

0.057

Total bilirubin (mg/dL)

0.9 [0.5 - 1.8]

1.0 [0.6 - 1.8]

1.0 [0.6 - 1.6]

0.839

Creatinine (mg/dL)

1.5 [1.0 - 1.9]

1.3 [0.9 - 2.0]

1.3 [1.0 - 2.0]

0.421

e-

Data are numbers (%) or medians (interquartile range).

pr

oo

f

Serum glucose maximum (mg/dL)

Chronic kidney disease is defined as either kidney damage or GFR <60mL/min/1.73 m2 for ≥ 3 months

a

Pr

PEA, pulseless electrical activity; BMI, body mass index; PCI, percutaneous coronary intervention; CABG, coronary artery bypass grafting; TTM, targeted temperature management; ECMO, extracorporeal membrane oxygenation. *

**

na l

p < 0.05 in the post hoc analysis between the asystole group and the PEA group. p < 0.05 in the post hoc analysis between the PEA group and the shockable rhythm group.

***

Jo ur

p < 0.05 in the post hoc analysis between the asystole group and the shockable rhythm group.

25

Variables

Asystole (n = 42)

PEA (n = 163)

Cause of arrest, ischemic

18 (42.9)

Defibrillation

12 (28.6)

CPR to pump-on time (min)

36.5 [20.0 - 55.0]

ROSC before ECMO

11 (26.2)

22 (52.4)

Catheterization laboratory Emergency room

76 (46.6)

52 (58.4)

0.128

36 (22.1)

83 (93.3)

< 0.001**,***

28.0 [18.0 - 43.5]

35.0 [22.0 - 51.0]

0.054

61 (37.4)

41 (46.1)

0.085

pr

oo

p value

0.325

89 (54.6)

44 (49.4)

17 (40.5)

49 (30.1)

27 (30.3)

3 (7.1)

25 (15.3)

18 (20.2)

41 (97.6)

160 (98.2)

87 (97.8)

0.963

5 (11.9)

13 (8.0)

13 (14.6)

0.543

Mechanical ventilation

36 (85.7)

141 (86.5)

80 (89.9)

0.695

Renal replacement therapy

17 (40.5)

67 (41.1)

30 (33.7)

0.500

Vasopressor

40 (95.2)

159 (97.5)

86 (96.6)

0.726

na l

Percutaneous insertion

Targeted temperature management

Jo ur

Post ECPR management

Pr

Intensive care unit

Shockable rhythm (n = 89)

e-

Location of insertion

f

Table 2 – Features, interventions, and post management of ECPR stratified by initial rhythm at ECPR

Data are numbers (%) or medians (interquartile range). PEA, pulseless electrical activity; CPR, cardiopulmonary resuscitation; ROSC, return of spontaneous circulation; ECMO, extracorporeal membrane oxygenation; ECPR, extracorporeal cardiopulmonary resuscitation. 26

oo

p < 0.05 in the post hoc analysis between the asystole group and the PEA group.

f

*

**

p < 0.05 in the post hoc analysis between the PEA group and the shockable rhythm group.

***

Jo ur

na l

Pr

e-

pr

p < 0.05 in the post hoc analysis between the asystole group and the shockable rhythm group.

27