Clinical profile, management, and outcome in patients with out of hospital cardiac arrest: insights from a 20-year registry

Systematic review of the relationship between comorbidity and out-of-hospital cardiac arrest outcomes

OBJECTIVES

To assess the current evidence on the effect pre-arrest comorbidity has on survival and neurological outcomes following out-of-hospital cardiac arrest (OHCA).

DESIGN

Systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

DATA SOURCES

MEDLINE, Ovid Embase, Scopus, CINAHL, Cochrane Library and MedNar were searched from inception to 31 December 2018.

ELIGIBILITY CRITERIA

Studies included if they examined the association between prearrest comorbidity and OHCA survival and neurological outcomes in adult or paediatric populations.

DATA EXTRACTION AND SYNTHESIS

Data were extracted from individual studies but not pooled due to heterogeneity. Quality of included studies was assessed using the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

This review included 29 observational studies. There were high levels of clinical heterogeneity between studies with regards to patient recruitment, inclusion criteria, outcome measures and statistical methods used which ultimately resulted in a high risk of bias. Comorbidities reported across the studies were diverse, with some studies reporting individual comorbidities while others reported comorbidity burden using tools like the Charlson Comorbidity Index. Generally, prearrest comorbidity was associated with both reduced survival and poorer neurological outcomes following OHCA with 79% (74/94) of all reported adjusted results across 23 studies showing effect estimates suggesting lower survival with 42% (40/94) of these being statistically significant. OHCA survival was particularly reduced in patients with a prior history of diabetes (four out of six studies). However, a prearrest history of myocardial infarction appeared to be associated with increased survival in one of four studies.

CONCLUSIONS

Prearrest comorbidity is generally associated with unfavourable OHCA outcomes, however differences between individual studies makes comparisons difficult. Due to the clinical and statistical heterogeneity across the studies, no meta-analysis was conducted. Future studies should follow a more standardised approach to investigating the impact of comorbidity on OHCA outcomes.

PROSPERO REGISTRATION NUMBER

CRD42018087578.

A novel approach to assess cerebral and coronary perfusion after cardiac arrest

BACKGROUND

Several indices exist to assess cerebral perfusion after cardiac arrest (CA). We aimed to investigate a new approach allowing absolute flow and microvascular resistance measurement based on selective arterial continuous thermodilution before and after CA resuscitation in a porcine model.

METHODS

In anaesthetised pigs, intravascular absolute cerebral blood flow (CBF) and absolute coronary blood flow (ABF) with corresponding microvascular resistances were measured. CA was induced using overdrive pacing with 3 (group 1, n = 5) or 5 min (group 2, n = 8) of no flow. After resuscitation, CBF was performed at baseline, at 15 min (T15) and at 30 min (T30). Thereafter, CBF in the contralateral cerebral artery and ABF were measured.

RESULTS

The protocol could not be completed in three pigs from group 2 due to haemodynamic instability. In the entire cohort, CBF was significantly lower at T30 after CA (0.026 ± 0.02 L/min vs 0.040 ± 0.03 at baseline; p = 0.03) and cerebral microvascular resistances were significantly higher (3202 ± 1838 Woods units vs 2014 ± 1015 at baseline; p = 0.04). ABF and resistances remained stable at baseline, as compared to T30 (0.122 ± 0.05 vs. 0.143 ± 0.06 L/min; p = 0.15 and 563 ± 203 vs. 478 ± 181 Woods units; p = 0.36, respectively). At T30, no significant differences in cerebral flow dynamics were observed between groups.

CONCLUSIONS

ABF and CBF measurement after CA resuscitation is feasible with thermodilution technique, allowing accurate monitoring and measurements. This novel approach allows simultaneous measurements of flow and microvascular resistances. This animal model simplifies cerebral perfusion measurements and allows to test new therapies to reduce cerebral injury post cardiac arrest.

Early Coronary Angiography for Survivors of Out-of-Hospital Cardiac Arrests Without ST Elevation

There are over 300,000 out-of-hospital cardiac arrests (OOHCA) in the United States each year, and the long-term survival rate is less than 10%. Despite improvements in postarrest management, the greatest drop-off in survival occurs during hospitalization, mostly due to myocardial dysfunction and neurological injury. Coronary artery disease is common in postcardiac arrest patients, with an incidence of approximately 60-80%. In patients with a chest pain syndrome and an ST-segment-elevation myocardial infarction pattern evident on the presenting electrocardiogram, immediate revascularization is recommended by cardiovascular societies due to established mortality benefits. However, it is less clear whether immediate or urgent coronary angiography for OOHCA survivors without ST elevation on the presenting electrocardiogram is beneficial. The current evidence base suggests that many OOHCA survivors, particularly when an acute coronary event is suspected, stand to benefit from early coronary angiography, although prospective trial data are lacking. Further studies are needed to identify whether all or even a subset of OOHCA survivors without ST elevation should undergo routine early coronary angiography.

Community involvement in out of hospital cardiac arrest: A cross-sectional study assessing cardiopulmonary resuscitation awareness and barriers among the Lebanese youth

Out of hospital cardiac arrest (OHCA) is a leading cause of death worldwide. Developing countries including Lebanon report low survival rates and poor neurologic outcomes in affected victims. Community involvement through early recognition and bystander cardiopulmonary resuscitation (CPR) can improve OHCA survival.This study assesses knowledge and attitude of university students in Lebanon and identifies potential barriers and facilitators to learning and performing CPR.A cross-sectional survey was administered to university students. The questionnaire included questions regarding the following data elements: demographics, knowledge, and awareness about sudden cardiac arrest, CPR, automated external defibrillator (AED) use, prior CPR and AED training, ability to perform CPR or use AED, barriers to performing/learning CPR/AED, and preferred location for attending CPR/AED courses. Descriptive analysis followed by multivariate analysis was carried out to identify predictors and barriers to learning and performing CPR.A total of 948 students completed the survey. Participants' mean age was 20.1 (±2.1) years with 53.1% women. Less than half of participants (42.9%) were able to identify all the presenting signs of cardiac arrest. Only 33.7% of participants felt able to perform CPR when witnessing a cardiac arrest. Fewer participants (20.3%) reported receiving previous CPR training. Several perceived barriers to learning and performing CPR were also reported. Significant predictors of willingness to perform CPR when faced with a cardiac arrest were: earning higher income, previous CPR training and feeling confident in one's ability to apply an AED, or perform CPR. Lacking enough expertise in performing CPR was a significant barrier to willingness to perform CPR.University students in Lebanon are familiar with the symptoms of cardiac arrest, however, they are not well trained in CPR and lack confidence to perform it. The attitude towards the importance of bystander CPR and the need to learn CPR is very positive. Interventions should focus on public awareness campaigns regarding the importance of initiating bystander CPR while activating emergency medical services (EMS) and on making CPR training more available.

Spatial decision on allocating automated external defibrillators (AED) in communities by multi-criterion two-step floating catchment area (MC2SFCA)

BACKGROUND

The occurrence of out-of-hospital cardiac arrest (OHCA) is a critical life-threatening event which frequently warrants early defibrillation with an automated external defibrillator (AED). The optimization of allocating a limited number of AEDs in various types of communities is challenging. We aimed to propose a two-stage modeling framework including spatial accessibility evaluation and priority ranking to identify the highest gaps between demand and supply for allocating AEDs.

METHODS

In this study, a total of 6135 OHCA patients were defined as demand, and the existing 476 publicly available AEDs locations and 51 emergency medical service (EMS) stations were defined as supply. To identify the demand for AEDs, Bayesian spatial analysis with the integrated nested Laplace approximation (INLA) method is applied to estimate the composite spatial risks from multiple factors. The population density, proportion of elderly people, and land use classifications are identified as risk factors. Then, the multi-criterion two-step floating catchment area (MC2SFCA) method is used to measure spatial accessibility of AEDs between the spatial risks and the supply of AEDs. Priority ranking is utilized for prioritizing deployment of AEDs among communities because of limited resources.

RESULTS

Among 6135 OHCA patients, 56.85 % were older than 65 years old, and 79.04 % were in a residential area. The spatial distribution of OHCA incidents was found to be concentrated in the metropolitan area of Kaohsiung City, Taiwan. According to the posterior mean estimated by INLA, the spatial effects including population density and proportion of elderly people, and land use classifications are positively associated with the OHCA incidence. Utilizing the MC2SFCA for spatial accessibility, we found that supply of AEDs is less than demand in most areas, especially in rural areas. Under limited resources, we identify priority places for deploying AEDs based on transportation time to the nearest hospital and population size of the communities.

CONCLUSION

The proposed method will be beneficial for optimizing resource allocation while considering multiple local risks. The optimized deployment of AEDs can broaden EMS coverage and minimize the problems of the disparity in urban areas and the deficiency in rural areas.