P2669Prognostication in out-of-hospital cardiac arrest

Abstract

Abstract Background Out-of-hospital cardiac arrest (OOHCA) remains an area where little progress has been made in outcomes despite significant advances in cardiac care. The OOHCA cohort requires a large amount of resources, including primary coronary intervention and intensive care, often with poor eventual outcomes. A clinical prognostic scoring system would allow resources to be focused on OOHCA patients who are likely to survive; rather than expensive and futile treatments in those who are not. Several different scoring systems have been published but have not been compared in a real world cohort of OOHCA patients. Method The Cardiac Arrest Hospital Prognosis (CAHP) score that utilises 7 variables and a simpler three-factor prognostic score derived by Hirt et al were applied retrospectively to a cohort of 157 consecutive OOHCA patients presenting to a regional Centre in our city, UK between 2016 and 2018. For each patient the CAHP score was calculated where a score of >200 predicts a Cerebral Performance Category (CPC) outcome of 3–5 (severe disability, vegetative coma or death). They were also categorised using the Hirt algorithm into “Futile”, “Approaching Futility” and “Non-Futile” groups. CPC outcomes were then compared using both scores and diagnostic accuracy assessed. Results A CAHP score of >200 predicted a CPC outcome of 3–5 with 97% specificity and a positive predictive value of 92%. A CAHP score >200 predicted 30-day mortality with 96% specificity, and a positive predictive value of 89% (Fig. 1A). The same cohort categorised by the Hirt algorithm was less accurate; in those patients sorted into the “futile” category 15% of patients survived, and in the “approaching futility” group survival was 100% (Fig. 1B). The specificity and PPV of predicting futility was 94% and 85% respectively. Conclusion Although a simple three-factor prognostic score as suggested by Hirt et al is attractive in this cohort of OOHCA patients it did not discriminate those patients who were likely to survive and, the CAHP score was more accurate in predicting outcome. Further validation is required in prospective, multi-centre studies to ensure that application of these scores are reproducible in real-world OOHCA populations in decision making for emergency coronary angiography. Acknowledgement/Funding None