Predicting the probability of survival with mild or moderate neurological dysfunction after in-hospital cardiopulmonary arrest: The GO-FAR 2 score

Validating the GO-FAR score: predicting in-hospital cardiac arrest outcomes in the Middle East

INTRODUCTION AND AIM

External validations of the Good Outcome Following Attempted Resuscitation (GO-FAR) score have been in populations where Do Not Attempt Resuscitation (DNAR) is practised. We aim to externally validate the GO-FAR score in a population without a DNAR order.

METHODS

We studied patients ≥ 18 years old who had an In-hospital cardiac arrest (IHCA) with known outcomes at Al Ain Hospital from January 2017 to December 2019, excluding those who died in the emergency department. Studied variables included demography, location, response time, code duration, initial rhythm, primary diagnosis, admission vital signs, GO FAR score variables, discharge status, and functional outcomes as determined by the cerebral performance category score ranging from 1 (good cerebral performance) to 5 (brain death).

RESULTS

366 patients were studied; 66.7% were males. The median (IQR) age was 70 (55-81) years. Cardiac and respiratory causes were the primary diagnoses in 89 (24.6%) and 67 (18.5%), respectively. IHCA occurred in critical areas such as the intensive care unit, high dependency unit and coronary care unit in 206 (80.8%) patients. The majority, 308 (91.8%), had a non-shockable rhythm, and a return of spontaneous circulation was achieved in 159 (43.4%) of the patients. Thirty-one (8.5%) patients survived to hospital discharge, and 20 (5.5%) patients had cerebral performance category scores of 1 and 2. The area under the curve of the ROC for survival to discharge with good functional outcome was 0.74 (95% CI 0.59-0.88). The best cut-off point for predicting survival with a good neurological outcome was a GO-FAR score of < 4, having a sensitivity of 0.81, a specificity of 0.7, a positive likelihood ratio of 2.7 and a negative likelihood ratio of 0.27.

CONCLUSIONS

A GO-FAR score of less than 4 predicts survival with a good neurological outcome in a healthcare system with an all-inclusive patient population with no DNAR practice.

Extracorporeal Membrane Oxygenation for Cardiac Arrest: Does Age Matter?

OBJECTIVES

The impact of age on hospital survival for patients treated with extracorporeal cardiopulmonary resuscitation (ECPR) for cardiac arrest (CA) is unknown. We sought to characterize the association between older age and hospital survival after ECPR, using a large international database.

DESIGN

Retrospective analysis of the Extracorporeal Life Support Organization registry.

PATIENTS

Patients 18 years old or older who underwent ECPR for CA between December 1, 2016, and October 31, 2020.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was adjusted odds ratio (aOR) of death after ECPR, analyzed by age group (18-49, 50-64, 65-74, and > 75 yr). A total of 5,120 patients met inclusion criteria. The median age was 57 years (interquartile range, 46-66 yr). There was a significantly lower aOR of survival for those 65-74 (0.68l 95% CI, 0.57-0.81) or those greater than 75 (0.54; 95% CI, 0.41-0.69), compared with 18-49. Patients 50-64 had a significantly higher aOR of survival compared with those 65-74 and greater than 75; however, there was no difference in survival between the two youngest groups (aOR, 0.91; 95% CI, 0.79-1.05). A sensitivity analysis using alternative age categories (18-64, 65-69, 70-74, and ≥ 75) demonstrated decreased odds of survival for age greater than or equal to 65 compared with patients younger than 65 (for age 65-69: odds ratio [OR], 0.71; 95% CI, 0.59-0.86; for age 70-74: OR, 0.84; 95% CI, 0.67-1.04; and for age ≥ 75: OR, 0.64; 95% CI, 0.50-0.81).

CONCLUSIONS

This investigation represents the largest analysis of the relationship of older age on ECPR outcomes. We found that the odds of hospital survival for patients with CA treated with ECPR diminishes with increasing age, with significantly decreased odds of survival after age 65, despite controlling for illness severity and comorbidities. However, findings from this observational data have significant limitations and further studies are needed to evaluate these findings prospectively.

External validation of GO-FAR 2 calculator for outcomes after in-hospital cardiac arrest with comparison to GO-FAR and trial of expanded applications

Aim

Externally validate the GO-FAR 2 tool for predicting survival with good neurologic function after in-hospital cardiac arrest with comparison to the original GO-FAR tool. Additionally, we collected qualitative descriptors and performed exploratory analyses with various levels of neurologic function and discharge destination.

Methods

Retrospective chart review of all patients who underwent in-hospital resuscitation after cardiac arrest during the calendar years 2016-2019 in our institution (n = 397). GO-FAR and GO-FAR 2 scores were calculated based on information available in the medical record at the time of hospital admission. Cerebral performance category (CPC) scores at the time of admission and discharge were assessed by chart review.

Results

The GO-FAR 2 score accurately predicted outcomes in our study population with a c-statistic of 0.625. The original GO-FAR score also had accurate calibration with a stronger c-statistic of 0.726. The GO-FAR score had decreased predictive value for lesser levels of neurologic function (c-statistic 0.56 for alive at discharge) and discharge destination (0.69). Descriptors of functional status by CPC score were collected.

Conclusion

Our findings support the validity of the GO-FAR and GO-FAR 2 tools as published, but the c-statistics suggest modest predictive discrimination. We include functional descriptors of CPC outcomes to aid clinicians in using these tools. We propose that information about expected outcomes could be valuable in shared decision-making conversations.

A model for predicting return of spontaneous circulation and neurological outcomes in adults after in-hospital cardiac arrest: development and evaluation

Introduction

In-hospital CA (IHCA) is associated with rates of high incidence, low return of spontaneous circulation (ROSC), low survival to discharge, and poor neurological outcomes. We aimed to construct and evaluate prediction models for non-return of spontaneous circulation (non-ROSC) and poor neurological outcomes 12 months after ROSC (PNO-12).

Methods

We retrospectively analyzed baseline and clinical data from patients experiencing cardiac arrest (CA) in a big academic hospital of Jilin University in China. Patients experiencing CA between September 1, 2019 and December 31, 2020 were categorized into the ROSC and non-ROSC groups. Patients maintaining ROSC >20 min were divided into the good and PNO-12 subgroups.

Results

Univariate and multivariate logistic regression identified independent factors associated with non-ROSC and PNO-12. Two nomogram prediction models were constructed and evaluated. Of 2,129 patients with IHCA, 851 were included in the study. Multivariate logistic regression analysis revealed that male sex, age >80 years, CPR duration >23 min, and total dose of adrenaline >3 mg were significant risk factors for non-ROSC. Before CA, combined arrhythmia, initial defibrillation rhythm, and advanced airway management (mainly as endotracheal intubation) also influenced outcomes. The area under the receiver operating characteristic curve in the prediction model was 0.904 (C-index: 0.901). Respiratory failure, shock, CA in the monitoring area, advanced airway management, and noradrenaline administration were independent risk factors for PNO-12. The AUC was 0.912 (C-index: 0.918).

Conclusions

Prediction models based on IHCA data could be helpful to reduce mortality rates and improve prognosis.

Predicting the probability of good neurological outcome after in-hospital cardiac arrest based on prearrest factors: validation of the good outcome following attempted resuscitation 2 (GO-FAR 2) score

The Good Outcome Following Attempted Resuscitation (GO-FAR) 2 score is a prognostic tool developed to support decision-making for do-not-attempt-resuscitation (DNAR) orders by predicting neurological outcomes after in-hospital cardiac arrest (IHCA) based on prearrest variables. However, this scoring system requires further validation. We aimed to validate the GO-FAR 2 score for predicting good neurological outcome in Korean patients with IHCA. A single-centre registry of adult patients with IHCA from 2013 to 2017 was analysed. The primary outcome was discharge with good neurological outcome (Cerebral Performance Category score of 1 or 2). The patients were divided into four categories according to the GO-FAR 2 score: very poor (≥ 5), poor (2-4), average (- 3 to 1), and above-average (< - 3) likelihood of good neurological outcome. Of 1,011 patients (median age, 65 years), 63.1% were men. The rate of good neurological outcome was 16.0%. The proportions of patients categorised as having very poor, poor, average, and above-average probability of good neurological outcome were 3.9%, 18.3%, 70.2%, and 7.6%, respectively. In each category, good neurological outcome was observed in 0%, 1.1%, 16.8%, and 53.2%, respectively. Among patients in below-average categories (very poor + poor, GO-FAR 2 score ≥ 2), only 0.9% had good outcome. GO-FAR 2 score ≥ 2 showed a sensitivity of 98.8% and a negative predictive value of 99.1% in predicting good neurological outcome. The GO-FAR 2 score can predict neurological outcome after IHCA. In particular, GO-FAR 2 score ≥ 2 may support decision-making for DNAR orders.

Lactate to Albumin Ratio for Predicting Clinical Outcomes after In-Hospital Cardiac Arrest

In-hospital cardiac arrest (IHCA) is associated with high mortality and poor neurological outcomes. Our objective was to assess whether the lactate-to-albumin ratio (LAR) can predict the outcomes in patients after IHCA. We retrospectively screened 75,987 hospitalised patients at a university hospital between 2015 and 2019. The primary endpoint was survival at 30-days. Neurological outcomes were assessed at 30 days using the cerebral performance category scale. 244 patients with IHCA and return of spontaneous circulation (ROSC) were included in this study and divided into quartiles of LAR. Overall, there were no differences in key baseline characteristics or rates of pre-existing comorbidities among the LAR quartiles. Patients with higher LAR had poorer survival after IHCA compared to patients with lower LAR: Q1, 70.4% of the patients; Q2, 50.8% of the patients; Q3, 26.2% of the patients; Q4, 6.6% of the patients (p = 0.001). Across increasing quartiles, the probability of a favourable neurological outcome in patients with ROSC after IHCA decreased: Q1: 49.2% of the patients; Q2: 32.8% of the patients; Q3: 14.7% of the patients; Q4: 3.2% of the patients (p = 0.001). The AUCs for predicting 30-days survival using the LAR were higher as compared to using a single measurement of lactate or albumin. The prognostic performance of LAR was superior to that of a single measurement of lactate or albumin for predicting survival after IHCA.

2022 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

This is the sixth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. This summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. Topics covered by systematic reviews include cardiopulmonary resuscitation during transport; approach to resuscitation after drowning; passive ventilation; minimizing pauses during cardiopulmonary resuscitation; temperature management after cardiac arrest; use of diagnostic point-of-care ultrasound during cardiac arrest; use of vasopressin and corticosteroids during cardiac arrest; coronary angiography after cardiac arrest; public-access defibrillation devices for children; pediatric early warning systems; maintaining normal temperature immediately after birth; suctioning of amniotic fluid at birth; tactile stimulation for resuscitation immediately after birth; use of continuous positive airway pressure for respiratory distress at term birth; respiratory and heart rate monitoring in the delivery room; supraglottic airway use in neonates; prearrest prediction of in-hospital cardiac arrest mortality; basic life support training for likely rescuers of high-risk populations; effect of resuscitation team training; blended learning for life support training; training and recertification for resuscitation instructors; and recovery position for maintenance of breathing and prevention of cardiac arrest. Members from 6 task forces have assessed, discussed, and debated the quality of the evidence using Grading of Recommendations Assessment, Development, and Evaluation criteria and generated consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections, and priority knowledge gaps for future research are listed.

Prognostic models for outcome prediction following in-hospital cardiac arrest using pre-arrest factors: a systematic review, meta-analysis and critical appraisal

BACKGROUND

Several prediction models of survival after in-hospital cardiac arrest (IHCA) have been published, but no overview of model performance and external validation exists. We performed a systematic review of the available prognostic models for outcome prediction of attempted resuscitation for IHCA using pre-arrest factors to enhance clinical decision-making through improved outcome prediction.

METHODS

This systematic review followed the CHARMS and PRISMA guidelines. Medline, Embase, Web of Science were searched up to October 2021. Studies developing, updating or validating a prediction model with pre-arrest factors for any potential clinical outcome of attempted resuscitation for IHCA were included. Studies were appraised critically according to the PROBAST checklist. A random-effects meta-analysis was performed to pool AUROC values of externally validated models.

RESULTS

Out of 2678 initial articles screened, 33 studies were included in this systematic review: 16 model development studies, 5 model updating studies and 12 model validation studies. The most frequently included pre-arrest factors included age, functional status, (metastatic) malignancy, heart disease, cerebrovascular events, respiratory, renal or hepatic insufficiency, hypotension and sepsis. Only six of the developed models have been independently validated in external populations. The GO-FAR score showed the best performance with a pooled AUROC of 0.78 (95% CI 0.69-0.85), versus 0.59 (95%CI 0.50-0.68) for the PAM and 0.62 (95% CI 0.49-0.74) for the PAR.

CONCLUSIONS

Several prognostic models for clinical outcome after attempted resuscitation for IHCA have been published. Most have a moderate risk of bias and have not been validated externally. The GO-FAR score showed the most acceptable performance. Future research should focus on updating existing models for use in clinical settings, specifically pre-arrest counselling. Systematic review registration PROSPERO CRD42021269235. Registered 21 July 2021.

Factors Related to Resuscitation Success and Prognosis of Cardiopulmonary Arrest Cases

Background

In cases where return of spontaneous circulation (ROSC) is provided in the Emergency Department (ED) after cardiopulmonary arrest (CA), it is important to investigate the parameters affecting ROSC rates, to determine the factors affecting the survival status and prognosis in the short and medium term, and to determine to what extent these factors affect the prognosis.

Materials and methods

This is a cross-sectional study that retrospectively investigates the factors affecting the success of resuscitation over a 5-year period in out-of-hospital cardiac arrest (OHCA) cases.

Results

We determined that ROSC was achieved in 26.1% of 1616 adult cardiopulmonary arrest cases, 14.8% survived the first 24 hours, and 3.8% were discharged from the hospital.

Conclusion

We determined that ROSC decreased by 21% with a 1-mg increase in the amount of adrenaline used, by 98% with a 1 mmol/L increase in HCO₃ (std) value, by 27% with a 1 mmol/L increase in BE (B) value, and by 15% with a 1 mmol/L increase in lactate value. In terms of short-term survival, we found that a 1 mmol/L increase in lactate value reduced the probability of survival by 12%, and a 1 mEq/L increase in K value decreased the probability by 29%. With regard to the probability of survival in the medium term, we determined that the growth in age by 1 year decreased the probability by 4%, and the increase in K value by 1 mEq/L decreased the probability by 35%.

How to cite this article

Tekin FC, Köylü R, Köylü O, Kunt M. Factors Related to Resuscitation Success and Prognosis of Cardiopulmonary Arrest Cases. Indian J Crit Care Med 2023;27(1):26-31.

2022 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

This is the sixth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. This summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. Topics covered by systematic reviews include cardiopulmonary resuscitation during transport; approach to resuscitation after drowning; passive ventilation; minimizing pauses during cardiopulmonary resuscitation; temperature management after cardiac arrest; use of diagnostic point-of-care ultrasound during cardiac arrest; use of vasopressin and corticosteroids during cardiac arrest; coronary angiography after cardiac arrest; public-access defibrillation devices for children; pediatric early warning systems; maintaining normal temperature immediately after birth; suctioning of amniotic fluid at birth; tactile stimulation for resuscitation immediately after birth; use of continuous positive airway pressure for respiratory distress at term birth; respiratory and heart rate monitoring in the delivery room; supraglottic airway use in neonates; prearrest prediction of in-hospital cardiac arrest mortality; basic life support training for likely rescuers of high-risk populations; effect of resuscitation team training; blended learning for life support training; training and recertification for resuscitation instructors; and recovery position for maintenance of breathing and prevention of cardiac arrest. Members from 6 task forces have assessed, discussed, and debated the quality of the evidence using Grading of Recommendations Assessment, Development, and Evaluation criteria and generated consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections, and priority knowledge gaps for future research are listed.

In-hospital cardiac arrest: the state of the art

In-hospital cardiac arrest (IHCA) is associated with a high risk of death, but mortality rates are decreasing. The latest epidemiological and outcome data from several cardiac arrest registries are helping to shape our understanding of IHCA. The introduction of rapid response teams has been associated with a downward trend in hospital mortality. Technology and access to defibrillators continues to progress. The optimal method of airway management during IHCA remains uncertain, but there is a trend for decreasing use of tracheal intubation and increased use of supraglottic airway devices. The first randomised clinical trial of airway management during IHCA is ongoing in the UK. Retrospective and observational studies have shown that several pre-arrest factors are strongly associated with outcome after IHCA, but the risk of bias in such studies makes prognostication of individual cases potentially unreliable. Shared decision making and advanced care planning will increase application of appropriate DNACPR decisions and decrease rates of resuscitation attempts following IHCA.

2022 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Pediatric Life Support; Neonatal Life Support; Education, Implementation, and Teams; and First Aid Task Forces

This is the sixth annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. This summary addresses the most recently published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. Topics covered by systematic reviews include cardiopulmonary resuscitation during transport; approach to resuscitation after drowning; passive ventilation; minimising pauses during cardiopulmonary resuscitation; temperature management after cardiac arrest; use of diagnostic point-of-care ultrasound during cardiac arrest; use of vasopressin and corticosteroids during cardiac arrest; coronary angiography after cardiac arrest; public-access defibrillation devices for children; pediatric early warning systems; maintaining normal temperature immediately after birth; suctioning of amniotic fluid at birth; tactile stimulation for resuscitation immediately after birth; use of continuous positive airway pressure for respiratory distress at term birth; respiratory and heart rate monitoring in the delivery room; supraglottic airway use in neonates; prearrest prediction of in-hospital cardiac arrest mortality; basic life support training for likely rescuers of high-risk populations; effect of resuscitation team training; blended learning for life support training; training and recertification for resuscitation instructors; and recovery position for maintenance of breathing and prevention of cardiac arrest. Members from 6 task forces have assessed, discussed, and debated the quality of the evidence using Grading of Recommendations Assessment, Development, and Evaluation criteria and generated consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence-to-Decision Framework Highlights sections, and priority knowledge gaps for future research are listed.

Pre-arrest Prediction of Survival Following In-hospital Cardiac Arrest: A Systematic Review of Diagnostic Test Accuracy Studies

AIM

To evaluate the test accuracy of pre-arrest clinical decision tools for in-hospital cardiac arrest survival outcomes.

METHODS

We searched Medline, Embase, and Cochrane Library from inception through January 2022 for randomized and non-randomized studies. We used the Quality Assessment of Diagnostic Accuracy Studies framework to evaluate risk of bias, and Grading of Recommendations Assessment, Development and Evaluation methodology to evaluate certainty of evidence. We report sensitivity, specificity, positive predictive outcome, and negative predictive outcome for prediction of survival outcomes. PROSPERO CRD42021268005.

RESULTS

We searched 2517 studies and included 23 studies using 13 different scores: 12 studies investigating 8 different scores assessing survival outcomes and 11 studies using 5 different scores to predict neurological outcomes. All were historical cohorts/ case control designs including adults only. Test accuracy for each score varied greatly. Across the 12 studies investigating 8 different scores assessing survival to hospital discharge/ 30-day survival, the negative predictive values (NPVs) for the prediction of survival varied from 55.6% to 100%. The GO-FAR score was evaluated in 7 studies with NPVs for survival with cerebral performance category (CPC) 1 ranging from 95.0% to 99.2%. Two scores assessed survival with CPC ≤2 and these were not externally validated. Across all prediction scores, certainty of evidence was rated as very low.

CONCLUSIONS

We identified very low certainty evidence across 23 studies for 13 different pre-arrest prediction scores to outcome following IHCA. No score was sufficiently reliable to support its use in clinical practice. We identified no evidence for children.

Quality of life and functional outcomes after in-hospital cardiopulmonary resuscitation. A systematic review

AIM

Our aim was to determine the association of cardiopulmonary resuscitation (CPR) for in hospital cardiac arrest (IHCA) with quality of life after discharge.

METHODS

We performed a systematic review using available databases for studies that measured any quality-of-life or functional outcome both before and after CPR for IHCA. All screening and data abstraction was performed in duplicate.

RESULTS

We screened 10,927 records and included 24 papers representing 20 unique studies. Fifteen studies measured Cerebral Performance Category. Survival ranged from 11.8% to 39.5%. The risk of impaired cerebral function after discharged ranged from -16.1% (lower risk) to 44.7% increased risk of poor cerebral function after surviving to discharge. Four studies measured discharge to an institutional environment finding that the risk was increased by 18.2-72.2% among survivors. One study measured EQ-5D and found no difference pre and post CPR. One study measured performance of activities of daily living finding that survivors needed assistance with more activities after discharge.

CONCLUSION

Our review is limited by the lack of adjustment for confounders, including the baseline level of each outcome, in all included studies. Therefore, although risk for most outcomes was increased after discharge vs pre-admission we cannot be certain if this is a causal relationship.

Long-Term Outcomes After In-Hospital Cardiac Arrest: Does Pre-arrest Skeletal Muscle Depletion Matter?

Background: Skeletal muscle depletion is prevalent in elderly patients and is associated with unfavorable outcomes in patients with chronic diseases. However, the relationship between skeletal muscle mass and neurological outcomes following in-hospital cardiac arrest (IHCA) has not been evaluated. The aim of this study was to investigate whether skeletal muscle status before cardiac arrest is an independent factor affecting neurological outcomes in patients with IHCA. Methods: We reviewed a prospectively enrolled registry of IHCA patients. Consecutive adult patients (>18 years) admitted to a tertiary care hospital from 2013 to 2019 were included in the study. Of these, 421 patients who underwent abdominopelvic computed tomography within 3 months of cardiac arrest were included. Skeletal muscle index (SMI) was measured at the third lumbar vertebra, and skeletal muscle depletion was defined using sex- and body mass index-specific cutoffs of SMI. The primary outcome was a Cerebral Performance Category score of 1 or 2 at 6 months after cardiac arrest, which was considered a good neurological outcome. Results: Of the 421 patients, 248 (58.9%) had skeletal muscle depletion before IHCA. The patients without skeletal muscle depletion showed significantly better neurological outcomes at 6 months after cardiac arrest than those with pre-arrest muscle depletion (20.8 vs. 10.9%, p = 0.004). The absence of skeletal muscle depletion was significantly associated with good neurological outcomes in a multivariable logistic analysis (OR = 3.49, 95% confidence intervals: 1.83-6.65, p < 0.001), along with the absence of diabetes, presence of active cancer, shockable rhythm, and short resuscitation duration. Conclusion: Pre-arrest skeletal muscle depletion was associated with long-term mortality and poor neurological outcomes after IHCA. Skeletal muscle depletion may be used as a tool to identify at-risk patients who may benefit from aggressive treatments.

Predictive value of pre-arrest albumin level with GO-FAR score in patients with in-hospital cardiac arrest

We investigated whether combining the pre-arrest serum albumin level could improve the performance of the Good Outcome Following Attempted Resuscitation (GO-FAR) score for predicting neurologic outcomes in in-hospital cardiac arrest patients. Adult patients who were admitted to a tertiary care hospital between 2013 and 2017 were assessed. Their pre-arrest serum albumin levels were measured within 24 h before the cardiac arrest. According to albumin levels, the patients were divided into quartiles and were assigned 1, 0, 0, and, - 2 points. Patients were allocated to the derivation (n = 419) and validation (n = 444) cohorts. The proportion of favorable outcome increased in a stepwise manner across increasing quartiles (p for trend < 0.018). Area under receiver operating characteristic curve (AUROC) of the albumin-added model was significantly higher than that of the original GO-FAR model (0.848 vs. 0.839; p = 0.033). The results were consistent in the validation cohort (AUROC 0.799 vs. 0.791; p = 0.034). Net reclassification indices of the albumin-added model were 0.059 (95% confidence interval [CI] - 0.037 to 0.094) and 0.072 (95% CI 0.013-0.132) in the derivation and validation cohorts, respectively. An improvement in predictive performance was found by adding the ordinal scale of pre-arrest albumin levels to the original GO-FAR score.

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.