Frequency of adjustment with comorbidity and illness severity scores and indices in cardiac arrest research

Comorbidities prior to out-of-hospital cardiac arrest and diagnoses at discharge among survivors

BACKGROUND

Out-of-hospital cardiac arrest (OHCA) has a dismal prognosis with overall survival around 10%. Previous studies have shown conflicting results regarding the prevalence and significance of comorbidities in OHCA, as well as the underlying causes. Previously, 80% of sudden cardiac arrest have been attributed to coronary artery disease. We studied comorbidities and discharge diagnoses in OHCA in all of Sweden.

METHODS

We used the Swedish Registry of Cardiopulmonary Resuscitation, merged with the Inpatient Registry and Outpatient Registry to identify patients with OHCA from 2010 to 2020 and to collect all their comorbidities as well as discharge diagnoses (among those admitted to hospital). Patient characteristics were described using means, medians and SD. Survival curves were performed among hospitalised patients with acute myocardial infarction (AMI) as well as heart failure.

RESULTS

A total of 54 484 patients with OHCA were included, of whom 35 894 (66%) were men. The most common comorbidities prior to OHCA were hypertension (43.6%), heart failure (23.6%), chronic ischaemic heart disease (23.6%) and atrial fibrillation (22.0%). Previous AMI was prevalent in 14.8% of men and 10.9% of women. Among women, 18.0% had type 2 diabetes, compared with 19.6% of the men. Among hospitalised patients, 30% were diagnosed with AMI, 27% with hypertension, 20% with ischaemic heart disease and 18% with heart failure as discharge diagnoses.

CONCLUSION

In summary, we find evidence that nowadays a minority of cardiac arrests are due to coronary artery disease and AMIs and its complications. Only 30% of all cases of OHCA admitted to hospital were diagnosed with AMI. Coronary artery disease is now likely in the minority with regard to causes of OHCA.

Age-adjusted Charlson Comorbidity Index as effective predictor for in-hospital mortality of patients with cardiac arrest: a retrospective study

BACKGROUND

Cardiac arrest is currently one of the leading causes of mortality in clinical practice, and the Charlson Comorbidity Index (CCI) is widely utilized to assess the severity of comorbidities. We aimed to evaluate the relationship between the age-adjusted CCI score and in-hospital mortality in intensive care unit (ICU) patients with the diagnosis of cardiac arrest, which is important but less explored previously.

METHODS

This was a retrospective study including patients aged over 18 years from the MIMIC-IV database. We calculated the age-adjusted CCI using age information and ICD codes. The univariate analysis for varied predictors' differences between the survival and the non-survival groups was performed. In addition, a multiple factor analysis was conducted based on logistic regression analysis with the primary result set as hospitalization death. An additional multivariate regression analysis was conducted to estimate the influence of hospital and ICU stay.

RESULTS

A total of 1772 patients were included in our study, with median age of 66, among which 705 (39.8%) were female. Amongst these patients, 963 (54.3%) died during the hospitalization period. Patients with higher age-adjusted CCI scores had a higher likelihood of dying during hospitalization (P < 0.001; OR: 1.109; 95% CI: 1.068-1.151). With the age-adjusted CCI incorporated into the predictive model, the area under the receiver operating characteristic curve was 0.794 (CI: 0.773-0.814), showing that the prediction model is effective. Additionally, patients with higher age-adjusted CCI scores stayed longer in the hospital (P = 0.026, 95% CI: 0.056-0.896), but there was no significant difference between patients with varied age-adjusted CCI scores on the days of ICU stay.

CONCLUSION

The age-adjusted CCI is a valid indicator to predict death in ICU patients with cardiac arrest, which can offer enlightenment for both theory literatures and clinical practice.

Characteristics, survival and neurological outcome in out-of-hospital cardiac arrest: A nationwide study of 56,203 cases with emphasis on cardiovascular comorbidities

Background

We studied clinical characteristics, survival and neurological outcomes in patients with pre-existing cardiovascular (CV) conditions who experienced an out-of-hospital cardiac arrest (OHCA).

Methods

We studied all cases of OHCA in the Swedish Registry for Cardiopulmonary Resuscitation (2010–2020). Patients were grouped according to the following pre-existing CV conditions prior: hypertension (HT), heart failure (HF) with HT, HF with ischemic heart disease (IHD), HF without HT or IHD, IHD, myocardial infarction (MI) and diabetes mellitus (DM), with groups being mutually exclusive. We studied 30-day survival and neurological outcomes using logistic and Cox regression.

Results

A total of 56,203 patients were included. The lowest rates of shockable rhythm occurred in cases with HT (19%), HF and HT (18%) and DM (18%). Median time to OHCA from diagnosis of HT was 2.0 years in cases aged 0–40 years at diagnosis of HT, 4.4 years in those aged 41–60 at diagnosis, 5.0 years in those aged 61–70 years, 5.6 years in those aged 71–80 years and 6.0 years in those aged 81 years or older. The lowest survival was noted for patients with HF and HT. Age and sex adjusted OR for CPC score 1 did not differ in any group.

Conclusion

The combination of HT and HF has the lowest survival of all cardiovascular comorbidities. Early onset of hypertension is a predictor for early cardiac arrest.

Comorbidity and bystander cardiopulmonary resuscitation in out-of-hospital cardiac arrest

​Objective

Cardiopulmonary resuscitation (CPR) performed before the arrival of emergency medical services (EMS) is associated with increased survival after out-of-hospital cardiac arrest (OHCA). The aim of this study was to determine whether patients who receive bystander CPR have a different comorbidity compared with patients who do not, and to determine the association between bystander CPR and 30-day survival when adjusting for such a possible difference.

​Methods

Patients with witnessed OHCA in the Swedish Registry for Cardiopulmonary Resuscitation between 2011 and 2015 were included, and merged with the National Patient Registry. The Charlson Comorbidity Index (CCI) was used to measure comorbidity. Multiple logistic regression was used to examine the effect of CCI on the association between bystander CPR and outcome.

​Results

In total, 11 955 patients with OHCA were included, 71% of whom received bystander CPR. Patients who received bystander CPR had somewhat lower comorbidity (CCI) than those who did not (mean±SD: 2.2±2.3 vs 2.5±2.4; p<0.0001). However, this difference in comorbidity had no influence on the association between bystander CPR and 30-day survival in a multivariable model including other possible confounders (OR 2.34 (95% CI 2.01 to 2.74) without adjustment for CCI and OR 2.32 (95% CI 1.98 to 2.71) with adjustment for CCI).

​Conclusion

Patients who undergo CPR before the arrival of EMS have a somewhat lower degree of comorbidity than those who do not. Taking this difference into account, bystander CPR is still associated with a marked increase in 30-day survival after OHCA.

Review article: Emergency endotracheal intubation in non-traumatic brain pathologies: A systematic review and meta-analysis

Endotracheal intubation is an advanced airway procedure performed in the ED and the out-of-hospital setting for acquired brain injuries that include non-traumatic brain pathologies such as stroke, encephalopathies, seizures and toxidromes. Controlled trial evidence supports intubation in traumatic brain injuries, but it is not clear that this evidence can be applied to non-traumatic brain pathologies. We sought to analyse the impact of emergency intubation on survival in non-traumatic brain pathologies and also to quantify the prevalence of intubation in these pathologies. We conducted a systematic literature search of Medline, Embase and the Cochrane Library. Eligibility, data extraction and assessment of risk of bias were assessed independently by two reviewers. A bias-adjusted meta-analysis using a quality-effects model pooled prevalence of intubation in non-traumatic brain pathologies. Forty-six studies were included in this systematic review. No studies were suitable for meta-analysis the primary outcome of survival. Thirty-nine studies reported the prevalence of intubation in non-traumatic brain pathologies and a meta-analysis showed that emergency intubation was used in 12% (95% CI 0-33) of pathologies. Endotracheal intubation was used commonly in haemorrhagic stroke 79% (95% CI 47-100) and to a lesser extent for seizures 18% (95% CI 10-27) and toxidromes 25% (95% CI 6-48). This systematic review shows that there is no high-quality clinical evidence to support or refute emergency intubation in non-traumatic brain pathologies. Our analysis shows that intubation is commonly used in non-traumatic brain pathologies, and the need for rigorous evidence is apparent.