Validation of Utstein-Based score to predict return of spontaneous circulation (UB-ROSC) in patients with out-of-hospital cardiac arrest.

BACKGROUND AND AIMS: The Utstein Based-ROSC (UB-ROSC) score has been developed to predict ROSC in OHCA victims. Aim of the study was to validate the UB-ROSC score using two Utstein-based OHCA registries: the SWiss REgistry of Cardiac Arrest (SWISSRECA) and the Lombardia Cardiac Arrest Registry (Lombardia CARe), northern Italy. METHODS: Consecutive patients with OHCA of any etiology occurring between January 1st, 2019 and December 31st 2021 were included in this retrospective validation study. UB-ROSC score was computed for each patient and categorized in one of three subgroups: low, medium or high likelihood of ROSC according to the UB-ROSC cut-offs (≤-19; -18 to 12; ≥13). To assess the performance of the UB-ROSC score in this new cohort, we assessed both discrimination and calibration. The score was plotted against the survival to hospital admission. RESULTS: A total of 12.577 patients were included in the study. A sustained ROSC was obtained in 2.719 patients (22%). The UB-ROSC model resulted well calibrated and showed a good discrimination (AUC 0.71, 95% CI 0.70-0.72). In the low likelihood subgroup of UB-ROSC, only 10% of patients achieved ROSC, whereas the proportion raised to 36% for a score between -18 and 12 (OR 5.0, 95% CI 2.9-8.6, p < 0.001) and to 85% for a score ≥13 (OR 49.4, 95% CI 14.3-170.6, p < 0.001). CONCLUSIONS: UB-ROSC score represents a reliable tool to predict ROSC probability in OHCA patients. Its application may help the medical decision-making process, providing a realistic stratification of the probability for ROSC.

Perceived threats and challenges experienced by first responders during their mission for an out-of-hospital cardiac arrest.

Aim: No study has systematically captured the perceived threat, discomfort or issues experienced by First Responders (FRs). We aimed to report the FRs' experience during a mission for an out-of-hospital cardiac arrest (OHCA) in a ten-year span. Methods: We collected all the 40-items questionnaires filled out by the FRs dispatched in Ticino Region (Switzerland) from 01/10/2010 to 31/12/2020. We compared results between FRs alerted by SMS or APP and between professional and citizen FRs. Results: 3391 FRs filled the questionnaire. The OHCA information was considered complete more frequently by FRs alerted by APP (85.6% vs 76.8%, p < 0.001), but a challenge in reaching the location was more frequent (15.5% vs 11.4%, p < 0.001), mainly due to wrong GPS coordinate. The FRs initiated/participated in resuscitation in 64.6% and used an AED in 31.9% of OHCAs, without issue in 97.9%. FRs reported a very high-level of satisfaction (97%) in EMS collaboration, but one-third didn't have the possibility to debrief. Citizen FRs used AED more frequently than professional FRs (34.6% vs 30.7%, p < 0.01), but experienced more often difficulties in performing CPR (2.6% vs 1.2%, p = 0.02) and wore more in need to debrief (19.7% vs 13%, p < 0.01). Conclusions: We provide a unique picture from the FRs' point of view during a real-life OHCA reporting high-level of satisfaction, great motivation but also the need of systematic debrief. We identified areas of improvements including geolocation accuracy, further training on AED use and support program dedicated to citizen FRs.

Impact of sex and role of coronary artery disease in out-of-hospital cardiac arrest presenting with refractory ventricular arrhythmias.

Introduction: There are limited data on sex-related differences in out-of hospital cardiac arrests (OHCAs) with refractory ventricular arrhythmias (VA) and, in particular, about their relationship with cardiovascular risk profile and severity of coronary artery disease (CAD). Purpose: Aim of this study was to characterize sex-related differences in clinical presentation, cardiovascular risk profile, CAD prevalence, and outcome in OHCA victims presenting with refractory VA. Methods: All OHCAs with shockable rhythm that occurred between 2015 and 2019 in the province of Pavia (Italy) and in the Canton Ticino (Switzerland) were included. Results: Out of 680 OHCAs with first shockable rhythm, 216 (33%) had a refractory VA. OHCA patients with refractory VA were younger and more often male. Males with refractory VA had more often a history of CAD (37% vs. 21%, p 0.03). In females, refractory VA were less frequent (M : F ratio 5 : 1) and no significant differences in cardiovascular risk factor prevalence or clinical presentation were observed. Male patients with refractory VA had a significantly lower survival at hospital admission and at 30 days as compared to males without refractory VA (45% vs. 64%, p < 0.001 and 24% vs. 49%, p < 0.001, respectively). Whereas in females, no significant survival difference was observed. Conclusions: In OHCA patients presenting with refractory VA the prognosis was significantly poorer for male patients. The refractoriness of arrhythmic events in the male population was probably due to a more complex cardiovascular profile and in particular due to a pre-existing CAD. In females, OHCA with refractory VA were less frequent and no correlation with a specific cardiovascular risk profile was observed.

End-tidal carbon dioxide (ETCO2) at intubation and its increase after 10 minutes resuscitation predicts survival with good neurological outcome in out-of-hospital cardiac arrest patients.

AIM: To evaluate whether end-tidal carbon dioxide (ETCO2) value at intubation and its early increase (10 min) after intubation predict both the survival to hospital admission and the survival at hospital discharge, including good neurological outcome (CPC 1-2), in patients with out-of-hospital cardiac arrest (OHCA). METHODS: All consecutive OHCA patients of any etiology between 2015 and 2018 in Pavia Province (Italy) and Ticino Region (Switzerland) were considered. Patients died before ambulance arrival, with a "do-not-resuscitate" order, without ETCO2 value or with incomplete data were excluded. RESULTS: The study population consisted of 668 patients. An ETCO2 value at intubation > 20 mmHg and its increase 10 min after intubation were independent predictors (after correction for known predictors of OHCA outcome) of survival to hospital admission and survival at hospital discharge. Relative to hospital discharge with good neurological outcome, ETCO2 at intubation and its 10-min change were confirmed predictors both individually and in a bivariable analysis (OR 1.83, 95 %CI 1.02-3.3; p = 0.04 and OR 3.9, 95 %CI 1.97-7.74; p < 0.001, respectively). This was confirmed also when accounting for gender, age, etiology and location. After further adjustment for bystander and CPR status, presenting rhythm and EMS arrival time, the ETCO2 change remained an independent predictor. CONCLUSIONS: ETCO2 value > 20 mmHg at intubation and its increase during resuscitation improve the prediction of survival at hospital discharge with good neurological outcome of OHCA patients. ETCO2 increase during resuscitation is a more powerful predictor than ETCO2 at intubation. A larger prospective study to confirm this finding appears warranted.

Spatio-temporal prediction model of out-of-hospital cardiac arrest: Designation of medical priorities and estimation of human resources requirement.

AIMS: To determine the out-of-hospital cardiac arrest (OHCA) rates and occurrences at municipality level through a novel statistical model accounting for temporal and spatial heterogeneity, space-time interactions and demographic features. We also aimed to predict OHCAs rates and number at municipality level for the upcoming years estimating the related resources requirement. METHODS: All the consecutive OHCAs of presumed cardiac origin occurred from 2005 until 2018 in Canton Ticino region were included. We implemented an Integrated Nested Laplace Approximation statistical method for estimation and prediction of municipality OHCA rates, number of events and related uncertainties, using age and sex municipality compositions. Comparisons between predicted and real OHCA maps validated our model, whilst comparisons between estimated OHCA rates in different yeas and municipalities identified significantly different OHCA rates over space and time. Longer-time predicted OHCA maps provided Bayesian predictions of OHCA coverages in varying stressful conditions. RESULTS: 2344 OHCAs were analyzed. OHCA incidence either progressively reduced or continuously increased over time in 6.8% of municipalities despite an overall stable spatio-temporal distribution of OHCAs. The predicted number of OHCAs accounts for 89% (2017) and 90% (2018) of the yearly variability of observed OHCAs with prediction error ≤1OHCA for each year in most municipalities. An increase in OHCAs number with a decline in the Automatic External Defibrillator availability per OHCA at region was estimated. CONCLUSIONS: Our method enables prediction of OHCA risk at municipality level with high accuracy, providing a novel approach to estimate resource allocation and anticipate gaps in demand in upcoming years.

A Bayesian spatiotemporal statistical analysis of out-of-hospital cardiac arrests.

We propose a Bayesian spatiotemporal statistical model for predicting out-of-hospital cardiac arrests (OHCAs). Risk maps for Ticino, adjusted for demographic covariates, are built for explaining and forecasting the spatial distribution of OHCAs and their temporal dynamics. The occurrence intensity of the OHCA event in each area of interest, and the cardiac risk-based clustering of municipalities are efficiently estimated, through a statistical model that decomposes OHCA intensity into overall intensity, demographic fixed effects, spatially structured and unstructured random effects, time polynomial dependence, and spatiotemporal random effect. In the studied geography, time evolution and dependence on demographic features are robust over different categories of OHCAs, but with variability in their spatial and spatiotemporal structure. Two main OHCA incidence-based clusters of municipalities are identified.

An Utstein-based model score to predict survival to hospital admission: The UB-ROSC score.

AIMS: To develop and validate a multi-parametric practical score to predict the probability of survival to hospital admission of an out-of-hospital cardiac arrest (OHCA) victim by using Utstein Style-based variables. METHODS: All consecutive OHCA cases occurring from 2015 to 2017 in two regions, Pavia Province (Italy) and Canton Ticino (Switzerland) were included. We used random effect logistic regression to model survival to hospital admission after an OHCA. We computed the model area under the ROC curve (AUC ROC) for discrimination and we performed both internal and external validation by considering all OHCAs occurring in the aforementioned regions in 2018. The Utstein-Based ROSC (UB-ROSC) score was derived by using the coefficients estimated in the regression model. The score value was obtained adding the pertinent score components calculated for each variable. The score was then plotted against the probability of survival to hospital admission. RESULTS: 1962 OHCAs were included (62% male, mean age 73 ± 16 years). Age, aetiology, location, witnessed OHCA, bystander CPR, EMS arrival time and shockable rhythm were independently associated with survival to hospital admission. The model showed excellent discrimination (AUC 0.83, 95%CI 0.81-0.85) for predicting survival to hospital admission, also at internal cross-validation (AUC 0.82, 95%CI 0.80-0.84). The model maintained good discrimination after external validation by using the 2018 OHCA cohort (AUC 0.77, 95%CI 0.74-0.80). CONCLUSIONS: UB-ROSC score is a novel score that predicts the probability of survival to hospital admission of an OHCA victim. UB-ROSC shall help in setting realistic expectations about sustained ROSC achievement during resuscitation manoeuvres.

Gender-specific differences in return-to-spontaneous circulation and outcome after out-of-hospital cardiac arrest: Results of sixteen-year-state-wide initiatives.

AIM: Several studies reported a lower proportion of laypeople cardio-pulmonary resuscitation (CPR) in female victims of out-of-hospital cardiac arrest (OHCA). We aimed to verify how sixteen-years of state-wide initiatives impacted on gender-differences in OHCA treatment and survival. METHODS: All the 2481 consecutive OHCAs of presumed cardiac origin occurred between 2002 and 2018 in the Swiss Ticino Canton and in which a resuscitation was attempted, were included. Emergency medical system (EMS)-witnessed OHCAs were excluded. RESULTS: Time from call to CPR decreased from 9-min in 2002-2006 to 5-min in 2015-2018 (p < 0.01) and until 2014, it was longer in women. Survival to discharge increased overall from 11% in 2002-2006 to 23% in 2015-2018 (p < 0.001) related to telephone-assisted CPR development (period 2011-2014) and first responder and layperson recruitment via a mobile application (period 2015-2018). In males, survival increased from 12% to 25% (p = 0.001) with a statistically significant increase in odds of survival in 2007-2010 (OR 1.6 95%CI 1.1-2.3; p = 0.001), in 2011-2014 (OR 2 95%CI 1.4-2.8; p = 0.001), and in 2015-2018 (2.4 95%CI 1.7-3.3; p = 0.001) compared to 2002-2006. On the other hand, in females, survival increased from 7% to 18% (p < 0.001), with a corresponding increase in the odds of survival of almost 3 times from 2002-2006 to 2015-2018 time period (OR 2.9 95%CI 1.5-5.8, p = 0.001). No difference in survival probability was observed according to gender when adjusted for age, presenting rhythm, year-groups, OHCA location, EMS arrival time, witnessed status and laypeople-CPR. CONCLUSIONS: State-wide initiatives can significantly increase the chances of survival in both male and female victims of OHCAs, by increasing the probability to receive CPR in a shorter time span.

Validation of the return of spontaneous circulation after cardiac arrest (RACA) score in two different national territories.

BACKGROUND: The likelihood of return of spontaneous circulation (ROSC) after out-of-hospital cardiac arrest (OHCA) is influenced by unmodifiable (gender, aetiology, location, the presence of witnesses and initial rhythm) and modifiable factors (bystander CPR and the time to EMS arrival). All of these have been included in the ROSC After Cardiac Arrest (RACA) score. PURPOSE: To test the ability of the RACA score to predict the probability of ROSC in two different regions with different local resuscitation networks: the Swiss Canton Ticino and the Italian Province of Pavia. METHODS AND RESULTS: All OHCAs occurred between January 1st 2015 and December 31st 2017 were included. The original regression coefficients for all RACA score variables were applied. The probability to obtain the ROSC as measured with the RACA score was divided in tertiles. Overall, 2041 OHCAs were included in the analysis. The RACA score showed good discrimination for ROSC (AUC 0.76) and calibration, without interaction (p 0.28) between the region and the probability of ROSC. The probability of ROSC was 15% for RACA scores <0.28, 20% for RACA scores between 0.28 and 0.42, increasing to 55% for RACA scores >0.42. CONCLUSIONS: The application of the RACA score reliably assess the probability to obtain the ROSC, with equal effectiveness in the two regions, despite different organization of the resuscitation network. Patients with a RACA score >0.42 had more than 50% probability to obtain ROSC.