Extracorporeal Life-Support For Out-Of-Hospital Cardiac Arrest: A Nationwide Multicenter Study

Extracorporeal cardiopulmonary resuscitation versus conventional CPR in cardiac arrest: an updated meta-analysis and trial sequential analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) may reduce mortality and improve neurological outcomes in patients with cardiac arrest. We updated our existing meta-analysis and trial sequential analysis to further evaluate ECPR compared to conventional CPR (CCPR).

METHODS

We searched three international databases from 1 January 2000 through 1 November 2023, for randomised controlled trials or propensity score matched studies (PSMs) comparing ECPR to CCPR in both out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA). We conducted an updated random-effects meta-analysis, with the primary outcome being in-hospital mortality. Secondary outcomes included short- and long-term favourable neurological outcome and survival (30 days-1 year). We also conducted a trial sequential analysis to evaluate the required information size in the meta-analysis to detect a clinically relevant reduction in mortality.

RESULTS

We included 13 studies with 14 pairwise comparisons (6336 ECPR and 7712 CCPR) in our updated meta-analysis. ECPR was associated with greater precision in reducing overall in-hospital mortality (OR 0.63, 95% CI 0.50-0.79, high certainty), to which the trial sequential analysis was concordant. The addition of recent studies revealed a newly significant decrease in mortality in OHCA (OR 0.62, 95% CI 0.45-0.84). Re-analysis of relevant secondary outcomes reaffirmed our initial findings of favourable short-term neurological outcomes and survival up to 30 days. Estimates for long-term neurological outcome and 90-day-1-year survival remained unchanged.

CONCLUSIONS

We found that ECPR reduces in-hospital mortality, improves neurological outcome, and 30-day survival. We additionally found a newly significant benefit in OHCA, suggesting that ECPR may be considered in both IHCA and OHCA.

How effective is extracorporeal life support for patients with out-of-hospital cardiac arrest initiated at the emergency department? A systematic review and meta-analysis

BACKGROUND

Extracorporeal cardiopulmonary resuscitation (ECPR) is commonly initiated for adults experiencing cardiac arrest within the cardiac catheterization lab or the intensive care unit. However, the potential benefit of ECPR for these patients in the emergency department (ED) remains undocumented. This study aims to assess the benefit of ECPR initiated in the ED for patients with out-of-hospital cardiac arrest (OHCA).

METHODS

We conducted a systematic review and meta-analysis of studies comparing ECPR initiated in the ED versus conventional CPR. Relevant articles were identified by searching several databases including PubMed, EMBASE, Web of Science, and Cochrane collaborations up to July 31, 2022. Pooled estimates were calculated using the inverse variance heterogeneity method, while heterogeneity was evaluated using Q and I2 statistics. The risk of bias in included studies was evaluated using validated bias assessment tools. The primary outcome was a favorable neurological outcome at hospital discharge, and the secondary outcome was survival to hospital discharge or 30-day survival. Sensitivity analyses were performed to explore the benefits of ED-initiated ECPR in studies utilizing propensity score (PPS) analysis. Publication bias was assessed using Doi plots and the Luis Furuya-Kanamori (LFK) index.

RESULTS

The meta-analysis included a total of eight studies comprising 51,173 patients. ED-initiated ECPR may not be associated with a significant increase in favorable neurological outcomes (odds ratio [OR] 1.43, 95% confidence interval [CI] 0.30-6.70, I2 = 96%). However, this intervention may be linked to improved survival to hospital discharge (OR 3.34, 95% CI 2.23-5.01, I2 = 17%). Notably, when analyzing only PPS data, ED-initiated ECPR demonstrated efficacy for both favorable neurological outcomes (OR 1.89, 95% CI 1.26-2.83, I2 = 21%) and survival to hospital discharge (OR 3.37, 95% CI 1.52-7.49, I2 = 57%). Publication bias was detected for primary (LFK index 2.50) and secondary (LFK index 2.14) outcomes.

CONCLUSION

The results of this study indicate that ED-initiated ECPR may not offer significant benefits in terms of favorable neurological outcomes for OHCA patients. However, it may be associated with increased survival to hospital discharge. Future studies should prioritize randomized trials with larger sample sizes and strive for homogeneity in patient populations to obtain more robust evidence in this area.

Extracorporeal cardiopulmonary resuscitation versus conventional cardiopulmonary resuscitation in adults with cardiac arrest: a comparative meta-analysis and trial sequential analysis

BACKGROUND

Although outcomes of patients after cardiac arrest remain poor, studies have suggested that extracorporeal cardiopulmonary resuscitation (ECPR) might improve survival and neurological outcomes. We aimed to investigate any potential benefits of using ECPR over conventional cardiopulmonary resuscitation (CCPR) in patients with out-of-hospital cardiac arrest (OHCA) and in-hospital cardiac arrest (IHCA).

METHODS

In this systematic review and meta-analysis, we searched MEDLINE via PubMed, Embase, and Scopus from Jan 1, 2000, to April 1, 2023, for randomised controlled trials and propensity-score matched studies. We included studies comparing ECPR with CCPR in adults (aged ≥18 years) with OHCA and IHCA. We extracted data from published reports using a prespecified data extraction form. We did random-effects (Mantel-Haenszel) meta-analyses and rated the certainty of evidence using the Grading of Recommendations, Assessments, Developments, and Evaluations (GRADE) approach. We rated the risk of bias of randomised controlled trials using the Cochrane risk-of-bias 2.0 tool, and that of observational studies using the Newcastle-Ottawa Scale. The primary outcome was in-hospital mortality. Secondary outcomes included complications during extracorporeal membrane oxygenation, short-term (from hospital discharge to 30 days after cardiac arrest) and long-term (≥90 days after cardiac arrest) survival with favourable neurological outcomes (defined as cerebral performance category scores 1 or 2), and survival at 30 days, 3 months, 6 months, and 1 year after cardiac arrest. We also did trial sequential analyses to evaluate the required information sizes in the meta-analyses to detect clinically relevant reductions in mortality.

FINDINGS

We included 11 studies (4595 patients receiving ECPR and 4597 patients receiving CCPR) in the meta-analysis. ECPR was associated with a significant reduction in overall in-hospital mortality (OR 0·67, 95% CI 0·51-0·87; p=0·0034; high certainty), without evidence of publication bias (pegger=0·19); the trial sequential analysis was concordant with the meta-analysis. When considering IHCA only, in-hospital mortality was lower in patients receiving ECPR than in those receiving CCPR (0·42, 0·25-0·70; p=0·0009), whereas when considering OHCA only, no differences were found (0·76, 0·54-1·07; p=0·12). Centre volume (ie, the number of ECPR runs done per year in each centre) was associated with reductions in odds of mortality (regression coefficient per doubling of centre volume -0·17, 95% CI -0·32 to -0·017; p=0·030). ECPR was also associated with an increased rate of short-term (OR 1·65, 95% CI 1·02-2·68; p=0·042; moderate certainty) and long-term (2·04, 1·41-2·94; p=0·0001; high certainty) survival with favourable neurological outcomes. Additionally, patients receiving ECPR had increased survival at 30-day (OR 1·45, 95% CI 1·08-1·96; p=0·015), 3-month (3·98, 1·12-14·16; p=0·033), 6-month (1·87, 1·36-2·57; p=0·0001), and 1-year (1·72, 1·52-1·95; p<0·0001) follow-ups.

INTERPRETATION

Compared with CCPR, ECPR reduced in-hospital mortality and improved long-term neurological outcomes and post-arrest survival, particularly in patients with IHCA. These findings suggest that ECPR could be considered for eligible patients with IHCA, although further research into patients with OHCA is warranted.

FUNDING

None.

Extracorporeal cardiopulmonary resuscitation for cardiac arrest: An updated systematic review

OBJECTIVES

To provide an updated systematic review on the use of extracorporeal cardiopulmonary resuscitation (ECPR) compared with manual or mechanical cardiopulmonary resuscitation during cardiac arrest.

METHODS

This was an update of a systematic review published in 2018. OVID Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched for randomized trials and observational studies between January 1, 2018, and June 21, 2022. The population included adults and children with out-of-hospital or in-hospital cardiac arrest. Two investigators reviewed studies for relevance, extracted data, and assessed bias. The certainty of evidence was evaluated using GRADE.

RESULTS

The search identified 3 trials, 27 observational studies, and 6 cost-effectiveness studies. All trials included adults with out-of-hospital cardiac arrest and were terminated before enrolling the intended number of subjects. One trial found a benefit of ECPR in survival and favorable neurological status, whereas two trials found no statistically significant differences in outcomes. There were 23 observational studies in adults with out-of-hospital cardiac arrest or in combination with in-hospital cardiac arrest, and 4 observational studies in children with in-hospital cardiac arrest. Results of individual studies were inconsistent, although many studies favored ECPR. The risk of bias was intermediate for trials and critical for observational studies. The certainty of evidence was very low to low. Study heterogeneity precluded meta-analyses. The cost-effectiveness varied depending on the setting and the analysis assumptions.

CONCLUSIONS

Recent randomized trials suggest potential benefit of ECPR, but the certainty of evidence remains low. It is unclear which patients might benefit from ECPR.

Prognostic value of early and late spontaneous conversion into a shockable rhythm for patients with out-of-hospital cardiac arrest

BACKGROUND

The prognostic significance of conversion into a shockable rhythm in patients who experienced out-of-hospital cardiac arrest (OHCA) with an initially nonshockable rhythm is controversial, perhaps due to the timing of rhythm conversion not being considered previously. We aimed to compare the different prognoses of patients with OHCA and early and late conversion of their rhythm into a shockable rhythm.

METHODS

This was a single-centre retrospective cohort study. We enrolled patients with OHCA who were sent to a medical centre in central Taiwan from 2016 to 2020. Patients <18 years old, those with cardiac arrest due to trauma or a circumstantial cause, and those for whom resuscitation was not attempted were excluded. Patients were divided into two groups in accordance with presentation with an initially shockable rhythm. Those with an initially nonshockable rhythm were divided into three subgroups: early-conversion, late-conversion, and nonconversion groups. The primary outcome was the neurological functional status upon discharge from hospital.

RESULTS

A total of 1645 patients with OHCA were included: initially shockable rhythm group, 339; early conversion group, 68; late-conversion group, 166; and nonconversion group, 1072. After adjustment, multivariate logistic regression revealed that a favourable neurological outcome was more common in the early conversion group than the nonconversion group (odds ratio [OR] 2.4; 95% confidence interval [CI], 1.1-5.3; p = 0.035), whereas the late-conversion group did not significantly differ from the nonconversion group (OR 0.5; 95% CI, 0.1-1.5; p = 0.211). The proportions of sustained return of spontaneous circulation and survival to discharge were also higher in the early conversion group than the late-conversion group (OR 2.9 95% CI 1.6-5.5, p = 0.001 and OR 4.5, 1.8-11.0, p = 0.001, respectively).

CONCLUSION

In patients who experience OHCA and have an initially nonshockable rhythm, early conversion into a shockable rhythm resulted in a better prognosis, whereas late conversion was not significantly different from nonconversion.