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

Abstract

ObjectivesTo assess the current evidence on the effect pre-arrest comorbidity has on survival and neurological outcomes following out-of-hospital cardiac arrest (OHCA).DesignSystematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.Data sourcesMEDLINE, Ovid Embase, Scopus, CINAHL, Cochrane Library and MedNar were searched from inception to 31 December 2018.Eligibility criteriaStudies included if they examined the association between prearrest comorbidity and OHCA survival and neurological outcomes in adult or paediatric populations.Data extraction and synthesisData were extracted from individual studies but not pooled due to heterogeneity. Quality of included studies was assessed using the Newcastle-Ottawa Quality Assessment Scale.ResultsThis 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.ConclusionsPrearrest 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 numberCRD42018087578

How Unexpected Is Out-of-hospital Sudden Cardiac Arrest? A Retrospective Cohort Study

“…These results are similar to other studies (e.g., an analysis of 40,000 patients from a 20-year registry found that patients with OHCA were more likely to have diabetes mellitus and myocardial infarction) (21). In addition, a systematic review analyzing the relationship between comorbidity and OHCA found that that prearrest comorbidities are associated with reduced survival and poorer neurological outcomes (22). Although the systematic review is limited by the high heterogeneity of the included studies, diabetes mellitus and myocardial infarction were especially demonstrated to be associated with poorer outcomes in OHCA patients.…”

Association between prehospital prognostic factors on out-of-hospital cardiac arrest in different age groups

“…The current study did not find significant differences between effects of comorbidities, including diabetes, hypertension, previous stroke, and liver disease, on survival of OHCA patients. A recent systemic review of 29 observational studies, attempted to find a relationship between pre-arrest comorbidity and outcomes of OHCA [ 34 ]. However, a meta-analysis was not performed in this review due to the clinical and statistical heterogeneity across the included studies.…”

Gastrointestinal bleeding is associated with higher in-hospital mortality, longer length of stay and higher cost in patients with in-hospital cardiac arrest

“… 1 Outcomes of in-hospital cardiac arrest depend on many factors including the cause of the cardiac arrest 2 and arrest rhythm. 3 While studies have found a higher Charlson Comorbidity Index (CCI) or the presence of certain comorbidities such as diabetes and renal disease is associated with a higher mortality in out-of-hospital cardiac arrests, 4 , 5 few studies have looked at the effects of comorbidities on the outcomes of IHCAs. Here we study the association between the presence of a secondary diagnosis gastrointestinal bleeding (GIB) and the outcomes of IHCA using the National Inpatient Sample (NIS).…”