Prediction of neurological outcomes following the return of spontaneous circulation in patients with out-of-hospital cardiac arrest: Retrospective fast-and-frugal tree analysis

Neuroprognostication in the Post Cardiac Arrest Patient: A Canadian Cardiovascular Society Position Statement

Cardiac arrest (CA) is associated with a low rate of survival with favourable neurologic recovery. The most common mechanism of death after successful resuscitation from CA is withdrawal of life-sustaining measures on the basis of perceived poor neurologic prognosis due to underlying hypoxic-ischemic brain injury. Neuroprognostication is an important component of the care pathway for CA patients admitted to hospital but is complex, challenging, and often guided by limited evidence. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system to evaluate the evidence underlying factors or diagnostic modalities available to determine prognosis, recommendations were generated in the following domains: (1) circumstances immediately after CA; (2) focused neurologic exam; (3) myoclonus and seizures; (4) serum biomarkers; (5) neuroimaging; (6) neurophysiologic testing; and (7) multimodal neuroprognostication. This position statement aims to serve as a practical guide to enhance in-hospital care of CA patients and emphasizes the adoption of a systematic, multimodal approach to neuroprognostication. It also highlights evidence gaps.

External validation of the TiPS65 score for predicting good neurological outcomes in patients with out-of-hospital cardiac arrest treated with extracorporeal cardiopulmonary resuscitation

AIM

Estimating prognosis of patients treated with extracorporeal cardiopulmonary resuscitation (ECPR) is essential for selecting candidates. The TiPS65 score can predict neurological outcomes of patients with out-of-hospital cardiac arrest (OHCA) treated with ECPR. We aimed to perform an external validation of this score.

METHODS

Data from the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest registry, a multicentred, nationwide, prospectively registered database, were analysed. All adult patients with OHCA and shockable rhythm and treated with ECPR between January 2018 to December 2019 were included. In the TiPS65 score, age, call-to-hospital arrival time, initial cardiac rhythm at hospital arrival, and initial pH value were used as predictors. The primary outcome was 30-day survival with favourable neurological outcomes (Cerebral Performance Category 1 or 2). Discrimination, using the C-statistic, and predictive performances of each score, such as sensitivity and specificity, were investigated.

RESULTS

Of 590 included patients (517 [81.6%] men; median [interquartile range] age, 60 [50-69] years), 64 (10.8%) reported favourable neurological outcomes. The C-statistic of the TiPS65 score was 0.729 (95% confidence interval (CI): 0.672-0.786). When the cut-off of TiPS65 score was set to >1, the sensitivity and specificity were 0.906 (95%CI: 0.807-0.965) and 0.430 (95%CI: 0.387-0.473), respectively; conversely, when the cut-off was set to >3, they were 0.172 (95%CI: 0.089-0.287) and 0.971 (95%CI: 0.953-0.984), respectively.

CONCLUSIONS

The TiPS65 score shows reasonable discrimination and predictive performances. This score can be supportive in the decision-making process for the selection of eligible patients for ECPR in clinical settings.

Prediction of return of spontaneous circulation in out-of-hospital cardiac arrest with non-shockable initial rhythm using point-of-care testing: a retrospective observational study

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) is a public health concern, and many studies have been conducted on return of spontaneous circulation (ROSC) and its prognostic factors. Rotational thromboelastometry (ROTEM^®), a point-of-care testing (POCT) method, has been useful for predicting ROSC in patients with OHCA, but very few studies have focused on patients with non-shockable rhythm. We examined whether the parameters of POCT could predict ROSC in patients with OHCA and accompanying non-shockable rhythm.

METHODS

This is a single-center, retrospective observational study. Complete blood count, blood gas, and ROTEM POCT measurements were used. This study included patients with non-traumatic OHCA aged 18 years or older who were transported to the emergency department and evaluated using POCT between January 2013 and December 2021. The patients were divided into the ROSC and non-ROSC groups. Prehospital information and POCT parameters were compared using receiver operating characteristic (ROC) curve analysis, and further logistic regression analysis was performed.

RESULTS

Sixty-seven and 135 patients were in the ROSC and non-ROSC groups, respectively. The ROC curves showed a high area under the curve (AUC) for K⁺ of 0.77 (95% confidence interval [CI]: 0.71-0.83) and EXTEM amplitude 5 min after clotting time (A5) of 0.70 (95%CI: 0.62-0.77). The odds ratios for ROSC were as follows: female sex 3.67 (95%CI: 1.67-8.04); K⁺ 0.64 (95%CI: 0.48-0.84); and EXTEM A5 1.03 (95%CI: 1.01-1.06).

CONCLUSION

In OHCA patients with non-shockable rhythm, K⁺ level and the ROTEM parameter EXTEM A5 may be useful in predicting ROSC.

Neuroprognostic Accuracy of Quantitative Versus Standard Pupillary Light Reflex for Adult Postcardiac Arrest Patients: A Systematic Review and Meta-Analysis

OBJECTIVES

An automated infrared pupillometer measures quantitative pupillary light reflex using a calibrated light stimulus. We examined whether the timing of performing quantitative pupillary light reflex or standard pupillary light reflex may impact its neuroprognostic performance in postcardiac arrest comatose patients and whether quantitative pupillary light reflex may outperform standard pupillary light reflex in early postresuscitation phase.

DATA SOURCES

PubMed and Embase databases from their inception to July 2020.

STUDY SELECTION

We selected studies providing sufficient data of prognostic values of standard pupillary light reflex or quantitative pupillary light reflex to predict neurologic outcomes in adult postcardiac arrest comatose patients.

DATA EXTRACTION

Quantitative data required for building a 2 × 2 contingency table were extracted, and study quality was assessed using standard criteria.

DATA SYNTHESIS

We used the bivariate random-effects model to estimate the pooled sensitivity and specificity of standard pupillary light reflex or quantitative pupillary light reflex in predicting poor neurologic outcome during early (< 72 hr), middle (between 72 and 144 hr), and late (≧ 145 hr) postresuscitation periods, respectively. We included 39 studies involving 17,179 patients. For quantitative pupillary light reflex, the cut off points used in included studies to define absent pupillary light reflex ranged from 0% to 13% (median: 7%) and from zero to 2 (median: 2) for pupillary light reflex amplitude and Neurologic Pupil index, respectively. Late standard pupillary light reflex had the highest area under the receiver operating characteristic curve (0.98, 95% CI [CI], 0.97-0.99). For early standard pupillary light reflex, the area under the receiver operating characteristic curve was 0.80 (95% CI, 0.76-0.83), with a specificity of 0.91 (95% CI, 0.85-0.95). For early quantitative pupillary light reflex, the area under the receiver operating characteristic curve was 0.83 (95% CI, 0.79-0.86), with a specificity of 0.99 (95% CI, 0.91-1.00).

CONCLUSIONS

Timing of pupillary light reflex examination may impact neuroprognostic accuracy. The highest prognostic performance was achieved with late standard pupillary light reflex. Early quantitative pupillary light reflex had a similar specificity to late standard pupillary light reflex and had better specificity than early standard pupillary light reflex. For postresuscitation comatose patients, early quantitative pupillary light reflex may substitute for early standard pupillary light reflex in the neurologic prognostication algorithm.

Association of the duration of on-scene advanced life support with good neurological recovery in out-of-hospital cardiac arrest

BACKGROUND

As advanced life support (ALS) provided by emergency medical services (EMS) on scene becomes more common, the scene time interval (STI) for which EMS providers stay on scene tends to lengthen. We investigated the relationship between the STI and neurological outcome of patients at hospital discharge when ALS was provided by EMS on scene.

METHODS

We conducted a retrospective analysis of prospectively collected out-of-hospital cardiac arrest (OHCA) data between August 2015 and December 2018. A restricted cubic spline curve was used to investigate the relationship between the STI and neurologic outcome, and patients were divided into two groups based on the cut-off value obtained through receiver operating characteristic (ROC) analysis. Comparisons of outcomes between the two groups were performed before and after propensity score matching.

RESULTS

4548 patients were included in the analysis. In ROC analysis, the optimal cut-off value for STI was 19 min. For the group with an STI <19 min, survival admission, survival discharge, and good neurologic outcome at hospital discharge were all higher than for the group with STI ≥19 min before and after propensity score matching. The multivariable model also showed that the STI ≥19 min was significantly associated with poor neurologic outcome at hospital discharge compared with the STI <19 min (adjusted odds ratio, 2.00; 95% CI, 1.40-2.88).

CONCLUSIONS

A duration of on-scene ALS more than 19 min was associated with a poor neurologic outcome of patients at hospital discharge in OHCA.

Gamma-Glutamyl Transpeptidase to Platelet Ratio: A New Inflammatory Marker Associated with Outcomes after Cardiac Arrest

Introduction

In recent years, gamma-glutamyl transpeptidase to platelet ratio (GPR) has been proposed as a new inflammatory marker. We aimed to evaluate the association between GPR and outcomes after cardiac arrest (CA).

Methods

A total of 354 consecutive patients with CA were included in this retrospective study. Patients were divided into three groups according to tertiles of GPR (low, n = 119; middle, n = 117; and high, n = 118). To determine the relationship between GPR and prognosis, a logistic regression analysis was performed. The ability of GPR to predict the outcomes was evaluated by receiver operating characteristic (ROC) curve analysis. Two prediction models were established, and the likelihood ratio test (LRT) and the Akaike Information Criterion (AIC) were utilized for model comparison.

Results

Among the 354 patients (age 62 [52, 74], 254/354 male) who were finally included in the analysis, those in the high GPR group had poor outcomes. Multivariate logistic regression analysis revealed that GPR was independently associated with the three outcomes, for ICU mortality (odds ratios (OR) = 1.738, 95% confidence interval (CI): 1.221-2.474, P = 0.002), hospital mortality (OR = 1.676[1.164 − 2.413], P = 0.005), and unfavorable neurologic outcomes (OR = 1.623[1.121 − 2.351], P = 0.010). The area under the ROC curve was 0.611 (95% Cl: 0.558-0.662) for ICU mortality, 0.600 (95% CI: 0.547-0.651) for hospital mortality, and 0.602 (95% CI: 0.549-0.653) for unfavorable neurologic outcomes. Further, the LRT analysis showed that compared with the model without GPR, the GPR-combined model had a higher likelihood ratio χ² score and smaller AIC.

Conclusion

GPR, as an inflammatory indicator, was independently associated with outcomes after CA. GPR is helpful in estimating the clinical outcomes of patients with CA.

Association between length of stay in the emergency department and outcomes in out-of-hospital cardiac arrest

OBJECTIVE

Several studies have previously reported that a prolonged emergency department length of stay (EDLOS) is associated with poor outcomes in critically ill patients. This study was performed to investigate the relationship between the EDLOS and the neurologic outcome at 28 days in out-of-hospital cardiac arrest (OHCA) patients.

METHODS

We conducted a retrospective analysis of prospectively collected data from OHCA patients who achieved the return of spontaneous circulation (ROSC) in the EDs of three urban tertiary teaching hospitals from December 2013 to October 2020. Patients were divided into four groups according to the EDLOS, according to the quartile distribution: EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min. Comparisons of outcomes among the groups and multivariable logistic regression analysis were performed.

RESULTS

A total of 807 patients were included in the analysis. The proportions of patients with a good neurologic outcome at 28 days in the groups with EDLOS <107 min, EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min were 37.0%, 29.8%, 26.9, and 20.4%, respectively (p < 0.001). In the multivariable analysis, the odds ratios for a poor neurologic outcome at 28 days in the groups with EDLOS 107-176 min, EDLOS 176-275 min, and EDLOS ≥275 min compared with the group with EDLOS <107 min were 1.19 (95% CI, 0.67-2.13), 1.73 (95% CI, 0.95-3.21), and 1.91 (95% CI, 1.03-3.57), respectively.

CONCLUSIONS

An EDLOS longer than 275 min after the ROSC was independently associated with a poor neurologic outcome at 28 days.

De-Ritis Ratio Is Associated with Mortality after Cardiac Arrest

INTRODUCTION

The aim of our study was to explore the associations of the aspartate transaminase/alanine transaminase (De-Ritis) ratio with outcomes after cardiac arrest (CA).

METHODS

This retrospective study included 374 consecutive adult cardiac arrest patients. Information on the study population was obtained from the Dryad Digital Repository. Patients were divided into tertiles based on their De-Ritis ratio. The logistic regression hazard analysis was used to assess the independent relationship between the De-Ritis ratio and mortality. The Kaplan-Meier method and log-rank test were used to estimate the survival of different groups. Receiver operating characteristic (ROC) curve analysis was utilized to compare the prognostic ability of biomarkers. A model combining the De-Ritis ratio was established, and its performance was evaluated using the Akaike information criterion (AIC).

RESULTS

Of the 374 patients who were included in the study, 194 patients (51.9%) died in the intensive care unit (ICU), 213 patients (57.0%) died during hospitalization, and 226 patients (60.4%) had an unfavorable neurologic outcome. Logistic regression analysis including potentially confounding factors showed that the De-Ritis ratio was independently associated with mortality, yielding a more than onefold risk of ICU mortality (OR 1.455; 95% CI 1.088-1.946; p = 0.011) and hospital mortality (OR 1.378; 95% CI 1.031-1.842; p = 0.030). Discriminatory performance assessed by ROC curves showed an area under the curve of 0.611 (95% CI 0.553-0.668) for ICU mortality and 0.625 (0.567-0.682) for hospital mortality. Further, the likelihood ratio test (LRT) analysis showed that the model combining the De-Ritis ratio had a smaller AIC and higher likelihood ratio χ 2 score than the model without the De-Ritis ratio. The Kaplan-Meier curves showed that the CA patients in the De-Ritis ratio tertile 3 group clearly had a significantly higher incidence of ICU mortality (log - rank = 0.007).

CONCLUSION

An elevated De-Ritis ratio on admission was significantly associated with ICU mortality and hospital mortality after CA. Assessment of the De-Ritis ratio might help identify groups at high risk for mortality.

Clinical Predictive Models of Sudden Cardiac Arrest: A Survey of the Current Science and Analysis of Model Performances

Background

More than 500 000 sudden cardiac arrests (SCAs) occur annually in the United States. Clinical predictive models (CPMs) may be helpful tools to differentiate between patients who are likely to survive or have good neurologic recovery and those who are not. However, which CPMs are most reliable for discriminating between outcomes in SCA is not known.

Methods and Results

We performed a systematic review of the literature using the Tufts PACE (Predictive Analytics and Comparative Effectiveness) CPM Registry through February 1, 2020, and identified 81 unique CPMs of SCA and 62 subsequent external validation studies. Initial cardiac rhythm, age, and duration of cardiopulmonary resuscitation were the 3 most commonly used predictive variables. Only 33 of the 81 novel SCA CPMs (41%) were validated at least once. Of 81 novel SCA CPMs, 56 (69%) and 61 of 62 validation studies (98%) reported discrimination, with median c‐statistics of 0.84 and 0.81, respectively. Calibration was reported in only 29 of 62 validation studies (41.9%). For those novel models that both reported discrimination and were validated (26 models), the median percentage change in discrimination was −1.6%. We identified 3 CPMs that had undergone at least 3 external validation studies: the out‐of‐hospital cardiac arrest score (9 validations; median c‐statistic, 0.79), the cardiac arrest hospital prognosis score (6 validations; median c‐statistic, 0.83), and the good outcome following attempted resuscitation score (6 validations; median c‐statistic, 0.76).

Conclusions

Although only a small number of SCA CPMs have been rigorously validated, the ones that have been demonstrate good discrimination.

Relationship Between Institutional Volume of Out-of-Hospital Cardiac Arrest Cases and 1-Month Neurologic Outcomes: A Post Hoc Analysis of a Prospective Observational Study

BACKGROUND

The influence of institutional volume of out-of-hospital cardiac arrest (OHCA) cases on outcomes remains unclear.

OBJECTIVES

This study evaluated the relationship between institutional volume of adult, nontraumatic OHCA cases and 1-month favorable neurologic outcomes.

METHODS

This study retrospectively analyzed data between January 2012 and March 2013 from a prospective observational study in the Kanto area of Japan. We analyzed adult patients with nontraumatic OHCA who underwent cardiopulmonary resuscitation by emergency medical service personnel and in whom spontaneous circulation was restored. Based on the institutional volume of OHCA cases, we divided institutions into low-, middle-, or high-volume groups. The primary and secondary outcomes were 1-month favorable neurologic outcomes and 1-month survival, respectively. A multivariate logistic regression analysis adjusted for propensity score and in-hospital variables was performed.

RESULTS

Of 2699 eligible patients, 889, 898, and 912 patients were transported to low-volume (40 institutions), middle-volume (14 institutions), and high-volume (9 institutions) centers, respectively. Using low-volume centers as the reference, transport to a middle- or high-volume center was not significantly associated with a favorable 1-month neurologic outcome (adjusted odds ratio [OR] 1.21 [95% confidence interval {CI} 0.84-1.75] and adjusted OR 0.77 [95% CI 0.53-1.12], respectively) or 1-month survival (adjusted OR 1.10 [95% CI 0.82-1.47] and adjusted OR 0.76 [95% CI 0.56-1.02], respectively).

CONCLUSIONS

Institutional volume was not significantly associated with favorable 1-month neurologic outcomes or 1-month survival in OHCA. Further investigation is needed to determine the association between hospital characteristics and outcomes in patients with OHCA.