External validation of Pittsburgh Cardiac Arrest Category illness severity score

doi:10.1016/j.resuscitation.2021.12.022

Resuscitation

Volume 172, March 2022, Pages 32-37

https://doi.org/10.1016/j.resuscitation.2021.12.022 Get rights and content

Abstract

Early prognostication post-cardiac arrest can help determine appropriate medical management and help evaluate effectiveness of post-arrest interventions. The Pittsburgh Cardiac Arrest Category (PCAC) severity score is a 4-level illness severity score found to strongly predict patient outcomes in both in- (IHCA) and out-of-hospital cardiac arrests (OHCA). We aimed to validate the PCAC severity score in an external cohort of cardiac arrest patients.

Methods

We retrospectively assigned PCAC scores to both IHCA and OHCA patients treated by our hypothermia team from July 1, 2009 to July 1 2016. Our primary outcome was survival to hospital discharge. Secondary outcomes were favorable functional status defined as favorable discharge disposition (home or acute rehabilitation), discharge Cerebral Performance Category (CPC); and discharge modified Rankin Scale (mRS). We tested the association of PCAC and outcomes using a multivariable adjusted logistic regression model.

Results

We included 317 subjects in our model. PCAC was strongly associated with survival I Reference; II adjusted odds ratio (OR) 0.20 95% confidence interval (CI) 0.35–0.66, III (OR 0.14 CI 0.3–0.73, p < 0.05); IV (OR 0.05 CI 0.01–0.24, p < 0.01). PCAC was similarly associated with favorable functional outcomes: favorable discharge disposition II (OR 0.12 CI 0.02–0.68), III (OR 0.19 CI 0.05–0.74, p < 0.05) IV (OR 0.05 CI 0.01–0.22, p < 0.01); favorable CPC score II (OR 0.25 CI 0.06–1.03), III (OR 0.14 CI 0.03–0.57, p < 0.01), IV (OR 0.05 CI 0.01–0.20, p < 0.01) and favorable mRS (OR 0.47 CI (0.33–0.68)).

Conclusion

Early (<6 h post-arrest) PCAC severity scoring strongly predicts patient outcomes from cardiac arrest in both OHCA and IHCA.

Introduction

Sudden cardiac arrest (SCA) and subsequent resuscitation often result in significant brain injury impairing survivorship.¹ While 40% of victims have return of spontaneous circulation (ROSC), failure to awaken from severe brain injury results in fewer than 10% surviving to hospital discharge.² SCA effects 395,000 annually,³ making it the third largest public disease burden.⁴ Early and effective post-cardiac arrest prognostication would help determine feasible medical management strategies⁵ and evaluate effectiveness of post-resuscitative therapeutics.⁶

Previously, Rittenberger et al. developed the Pittsburgh Cardiac Arrest Category (PCAC) illness severity score based on the most important determinants of cardiac arrest outcomes.⁷ PCAC is a simple scoring system that allows for immediate post-arrest (<6 h) prognostication in both out-of-hospital (OHCA) and in-hospital cardiac arrest (IHCA). PCAC was found to be strongly associated with survival to hospital discharge and favorable outcomes. Coppler et al. subsequently validated within similar geographic region the association of prospective PCAC scoring and functional neurological outcome in a high volume post-cardiac arrest service in the United States.⁸

We aimed to externally validate the association of PCAC scoring with cardiac arrest outcomes in a different regional cohort. We hypothesized that PCAC would predict survival to hospital discharge and favorable outcomes similar to original foundational models.

Section snippets

Design

We conducted a secondary analysis of a quality improvement database maintained by the University of Alabama at Birmingham (UAB) Post-Cardiac Arrest Service. We engaged in a retrospective cohort study of consecutive patients after resuscitation from cardiac arrest and treated with targeted temperature management. The UAB Institutional Review Board approved the analysis of our database and deemed it was exempt from requirement to obtain informed consent. This report follows the Strengthening the

Results

Over a seven-year period, 352 subjects were eligible. After excluding 35 for incomplete data, we present the resulting 317 subjects (47 in-hospital cardiac arrests and 270 OHCA). Most subjects were in their 7th decade of life and suffered OHCA. Frequency of VT/VF as the initial rhythm was less frequent as PCAC severity increased (relative 51% decrease PCAC I vs PCAC IV, p < 0.05). Use of hypothermia increased with more severe PCAC illness severity (relative 60% increase PCAC I vs PCAC IV, p

Discussion

Similar to previous studies, we confirmed that PCAC is associated with survival to discharge and favorable outcomes after cardiac arrest. Initial PCAC derivation and validation studies were performed in the same geographical location.7., 8. We confirmed PCAC foundational studies with an external patient population and separate group of evaluators. This strengthens the potential generalizability of PCAC scoring to all cardiac arrest patients.

Similar to PCAC foundational studies, our patient

Conclusions

In this study we validated the ability of PCAC to predict post-ROSC outcomes after cardiac arrest. Scoring is dynamic in the post arrest period but may be useful in evaluating post-arrest resuscitation interventions. PCAC may play a key role in post-arrest assessment and care.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

CRediT authorship contribution statement

Michelle M.J. Nassal: Conceptualization, Methodology, Validation, Formal analysis, Visualization. Dylan Nichols: Methodology, Validation, Formal analysis. Stephanie Demasi: Validation. Jon C. Rittenberger: Validation, Writing – review & editing. Ashish R. Panchal: Conceptualization, Formal analysis, Supervision. Michael C. Kurz: Conceptualization, Formal analysis, Supervision, Project administration.

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Cited by (8)

Brain computed tomography after resuscitation from in-hospital cardiac arrest
2024, Resuscitation
Few data characterize the role of brain computed tomography (CT) after resuscitation from in-hospital cardiac arrest (IHCA). We hypothesized that identifying a neurological etiology of arrest or cerebral edema on brain CT are less common after IHCA than after resuscitation from out-of-hospital cardiac arrest (OHCA).
We included all patients comatose after resuscitation from IHCA or OHCA in this retrospective cohort analysis. We abstracted patient and arrest clinical characteristics, as well as pH and lactate, to estimate systemic illness severity. Brain CT characteristics included quantitative measurement of the grey-to-white ratio (GWR) at the level of the basal ganglia and qualitative assessment of sulcal and cisternal effacement. We compared GWR distribution by stratum (no edema ≥1.30, mild-to-moderate <1.30 and >1.20, severe ≤1.20) and newly identified neurological arrest etiology between IHCA and OHCA groups.
We included 2,306 subjects, of whom 420 (18.2%) suffered IHCA. Fewer IHCA subjects underwent post-arrest brain CT versus OHCA subjects (149 (35.5%) vs 1,555 (82.4%), p < 0.001). Cerebral edema for IHCA versus OHCA was more often absent (60.1% vs. 47.5%) or mild-to-moderate (34.3% vs. 27.9%) and less often severe (5.6% vs. 24.6%). A neurological etiology of arrest was identified on brain CT in 0.5% of IHCA versus 3.2% of OHCA.
Although severe edema was less frequent in IHCA relative to OHCA, mild-to-moderate or severe edema occurred in one in three patients after IHCA. Unsuspected neurological etiologies of arrest were rarely discovered by CT scan in IHCA patients.
Diagnostic yield of computed tomography after non-traumatic out-of-hospital cardiac arrest
2023, Resuscitation
Determine the frequency with which computed tomography (CT) after out-of-hospital cardiac arrest (OHCA) identifies clinically important findings.
We included non-traumatic OHCA patients treated at a single center from February 2019 to February 2021. Clinical practice was to obtain CT head in comatose patients. Additionally, CT of the cervical spine, chest, abdomen, and pelvis were obtained if clinically indicated. We identified CT imaging obtained within 24 hours of emergency department (ED) arrival and summarized radiology findings. We used descriptive statistics to summarize population characteristics and imaging results, report their frequencies and, post hoc, compared time from ED arrival to catheterization between patients who did and did not undergo CT.
We included 597 subjects, of which 491 (82.2%) had a CT obtained. Time to CT was 4.1 hours [2.8–5.7]. Most (n = 480, 80.4%) underwent CT head, of which 36 (7.5%) had intracranial hemorrhage and 161 (33.5%) had cerebral edema. Fewer subjects (230, 38.5%) underwent a cervical spine CT, and 4 (1.7%) had acute vertebral fractures. Most subjects (410, 68.7%) underwent a chest CT, and abdomen and pelvis CT (363, 60.8%). Chest CT abnormalities included rib or sternal fractures (227, 55.4%), pneumothorax (27, 6.6%), aspiration or pneumonia (309, 75.4%), mediastinal hematoma (18, 4.4%) and pulmonary embolism (6, 3.7%). Significant abdomen and pelvis findings were bowel ischemia (24, 6.6%) and solid organ laceration (7, 1.9%). Most subjects that had CT imaging deferred were awake and had shorter time to catheterization.
CT identifies clinically important pathology after OHCA.
Duration of cardiopulmonary resuscitation and phenotype of post-cardiac arrest brain injury
2023, Resuscitation
Patients resuscitated from cardiac arrest have variable severity of primary hypoxic ischemic brain injury (HIBI). Signatures of primary HIBI on brain imaging and electroencephalography (EEG) include diffuse cerebral edema and burst suppression with identical bursts (BSIB). We hypothesize distinct phenotypes of primary HIBI are associated with increasing cardiopulmonary resuscitation (CPR) duration.
We identified from our prospective registry of both in-and out-of-hospital CA patients treated between January 2010 to January 2020 for this cohort study. We abstracted CPR duration, neurological examination, initial brain computed tomography gray to white ratio (GWR), and initial EEG pattern. We considered four phenotypes on presentation: awake; comatose with neither BSIB nor cerebral edema (non-malignant coma); BSIB; and cerebral edema (GWR ≤ 1.20). BSIB and cerebral edema were considered as non-mutually exclusive outcomes. We generated predicted probabilities of brain injury phenotype using localized regression.
We included 2,440 patients, of whom 545 (23%) were awake, 1,065 (44%) had non-malignant coma, 548 (23%) had BSIB and 438 (18%) had cerebral edema. Only 92 (4%) had both BSIB and edema. Median CPR duration was 16 [IQR 8–28] minutes. Median CPR duration increased in a stepwise manner across groups: awake 6 [3–13] minutes; non-malignant coma 15 [8–25] minutes; BSIB 21 [13–31] minutes; cerebral edema 32 [22–46] minutes. Predicted probability of phenotype changes over time.
Brain injury phenotype is related to CPR duration, which is a surrogate for severity of HIBI. The sequence of most likely primary HIBI phenotype with progressively longer CPR duration is awake, coma without BSIB or edema, BSIB, and finally cerebral edema.
Validation of the rCAST score and comparison to the PCAC and FOUR scores for prognostication after out-of-hospital cardiac arrest
2023, Resuscitation
Early, accurate outcome prediction after out-of-hospital cardiac arrest (OHCA) is critical for clinical decision-making and resource allocation. We sought to validate the revised post-Cardiac Arrest Syndrome for Therapeutic hypothermia (rCAST) score in a United States cohort and compare its prognostic performance to the Pittsburgh Cardiac Arrest Category (PCAC) and Full Outline of UnResponsiveness (FOUR) scores.
This is a single-center, retrospective study of OHCA patients admitted between January 2014-August 2022. Area under the receiver operating curve (AUC) was computed for each score for predicting poor neurologic outcome at discharge and in-hospital mortality. We compared the scores’ predictive abilities via Delong’s test.
Of 505 OHCA patients with all scores available, the medians [IQR] for rCAST, PCAC, and FOUR scores were 9.5 [6.0, 11.5], 4 [3, 4], and 2 [0, 5], respectively. The AUC [95% confidence interval] of the rCAST, PCAC, and FOUR scores for predicting poor neurologic outcome were 0.815 [0.763–0.867], 0.753 [0.697–0.809], and 0.841 [0.796–0.886], respectively. The AUC [95% confidence interval] of the rCAST, PCAC, and FOUR scores for predicting mortality were 0.799 [0.751–0.847], 0.723 [0.673–0.773], and 0.813 [0.770–0.855], respectively. The rCAST score was superior to the PCAC score for predicting mortality (p = 0.017). The FOUR score was superior to the PCAC score for predicting poor neurological outcome (p < 0.001) and mortality (p < 0.001).
The rCAST score can reliably predict poor outcome in a United States cohort of OHCA patients regardless of TTM status and outperforms the PCAC score.
A novel cardiac arrest severity score for the early prediction of hypoxic-ischemic brain injury and in-hospital death
2023, American Journal of Emergency Medicine
Out-of-hospital cardiac arrest (OHCA) outcomes are unsatisfactory despite postcardiac arrest care. Early prediction of prognoses might help stratify patients and provide tailored therapy. In this study, we derived and validated a novel scoring system to predict hypoxic-ischemic brain injury (HIBI) and in-hospital death (IHD).
We retrospectively analyzed Korean Hypothermia Network prospective registry data collected from in Korea between 2015 and 2018. Patients without neuroprognostication data were excluded, and the remaining patients were randomly divided into derivation and validation cohorts. HIBI was defined when at least one prognostication predicted a poor outcome. IHD meant all deaths regardless of cause. In the derivation cohort, stepwise multivariate logistic regression was conducted for the HIBI and IHD scores, and model performance was assessed. We then classified the patients into four categories and analyzed the associations between the categories and cerebral performance categories (CPCs) at hospital discharge. Finally, we validated our models in an internal validation cohort.
Among 1373 patients, 240 were excluded, and 1133 were randomized into the derivation (n = 754) and validation cohorts (n = 379). In the derivation cohort, 7 and 8 predictors were selected for HIBI (0–8) and IHD scores (0−11), respectively, and the area under the curves (AUC) were 0.85 (95% CI 0.82–0.87) and 0.80 (95% CI 0.77–0.82), respectively. Applying optimum cutoff values of ≥6 points for HIBI and ≥7 points for IHD, the patients were classified as follows: HIBI (−)/IHD (−), Category 1 (n = 424); HIBI (−)/IHD (+), Category 2 (n = 100); HIBI (+)/IHD (−), Category 3 (n = 21); and HIBI (+)/IHD (+), Category 4 (n = 209). The CPCs at discharge were significantly different in each category (p < 0.001). In the validation cohort, the model showed moderate discrimination (AUC 0.83, 95% CI 0.79–0.87 for HIBI and AUC 0.77, 95% CI 0.72–0.81 for IHD) with good calibration. Each category of the validation cohort showed a significant difference in discharge outcomes (p < 0.001) and a similar trend to the derivation cohort.
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Illness severity may identify patients who will benefit from hypothermia
2022, Resuscitation

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¹: See Appendix A.

View full text

Clinical paperExternal validation of Pittsburgh Cardiac Arrest Category illness severity score

Abstract

Methods

Results

Conclusion

Introduction

Section snippets

Design

Results

Discussion

Conclusions

Declaration of Competing Interest

CRediT authorship contribution statement

Resuscitation

Resuscitation

Resuscitation

Resuscitation

Resuscitation

Resuscitation

Resuscitation

Sudden cardiac arrest survivorship: a scientific statement from the American Heart Association

Circulation

Heart Disease and Stroke Statistics-2020 update: a report from the American Heart Association

Circulation

Abstract 149: Annual and Lifetime Economic Productivity Loss Due to Adult Out-of-hospital Cardiac Arrest in the United States

Circulation

Comparison of the new high sensitive cardiac troponin T with myoglobin, h-FABP and cTnT for early identification of myocardial necrosis in the acute coronary syndrome

Clin Res Cardiol

Coronary angiography after cardiac arrest - the right timing or the right patients?

N Engl J Med

The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for reporting observational studies

Ann Intern Med

Post-cardiac arrest therapeutic hypothermia: overcoming the barrier of workplace culture and other implementation lessons

Jt Comm J Qual Patient Saf

Validation of a new coma scale: The FOUR score

Ann Neurol

Clinical paper
External validation of Pittsburgh Cardiac Arrest Category illness severity score