Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study: sequential mixed-methods study protocol in Michigan, USA.

INTRODUCTION: Out-of-hospital cardiac arrest (OHCA) is a common, life-threatening event encountered routinely by first responders, including police, fire and emergency medical services (EMS). Current literature suggests that there is significant regional variation in outcomes, some of which may be related to modifiable factors. Yet, there is a persistent knowledge gap regarding strategies to guide quality improvement efforts in OHCA care and, by extension, survival. The Enhancing Prehospital Outcomes for Cardiac Arrest (EPOC) study aims to fill these gaps and to improve outcomes. METHODS AND ANALYSIS: This mixed-methods study includes three aims. In aim I, we will define variation in OHCA survival to the emergency department (ED) among EMS agencies that participate in the Michigan Cardiac Arrest Registry to Enhance Survival (CARES) in order to sample EMS agencies with high-survival and low-survival outcomes. In aim II, we will conduct site visits to emergency medical systems-including 911/dispatch, police, non-transport fire, and EMS agencies-in approximately eight high-survival and low-survival communities identified in aim I. At each site, key informant interviews and a multidisciplinary focus group will identify themes associated with high OHCA survival. Transcripts will be coded using a structured codebook and analysed through thematic analysis. Results from aims I and II will inform the development of a survey instrument in aim III that will be administered to all EMS agencies in Michigan. This survey will test the generalisability of factors associated with increased OHCA survival in the qualitative work to ultimately build an EPOC Toolkit which will be distributed to a broad range of stakeholders as a practical 'how-to' guide to improve outcomes. ETHICS AND DISSEMINATION: The EPOC study was deemed exempt by the University of Michigan Institutional Review Board. Findings will be compiled in an 'EPOC Toolkit' and disseminated in the USA through partnerships including, but not limited to, policymakers, EMS leadership and health departments.

Intrastate Variation in Treatment and Outcomes of Out-of-Hospital Cardiac Arrest.

OBJECTIVE: Our objective was to analyze and compare out-of-hospital cardiac arrest (OHCA) system of care performance and outcomes at the Medical Control Authority (MCA) level in the state of Michigan. We hypothesized that clinically and statistically significant variations in treatment and outcomes of OHCA exists within a single U.S. state. METHODS: We performed a retrospective, observational study of all non-traumatic EMS-treated OHCA from the state of Michigan CARES registry for 2014-2015. Geocoding of the OHCA incident address was used to assign records to individual MCAs. MCA-based demographics, arrest characteristics, system of care performance and outcomes were quantified and compared. Associations between demographics, system of care parameters, and outcomes were examined at the MCA level. RESULTS: A total of 8,115 records with complete data were available for analysis. Eleven MCAs met study inclusion criteria of >100 cases, producing a final sample size of 7,788 records (96%). Statistically significant variations in survival to hospital discharge ranged from 4.5% to 15% (p < 0.001) (Adjusted odds ratio [AOR] range 0.6-2.0) and survival with good neurologic outcome 2.7-12.5% (p < 0.001; AOR range 0.5-2.2,) were observed across MCAs. Bystander CPR ranged from 32% to 53% (p < 0.001) and bystander AED application ranged from 3.5% 11.5% (p < 0.05). Of patients admitted to the hospital alive, 29-68% received targeted temperature management. In hospital mortality ranged from 53.1% to 73.9% (p < 0.05). CONCLUSION: Significant intrastate variability in OHCA system of care performance and outcomes currently exist and are similar to what has been previously reported across North America almost a decade ago. This degree of variability highlights the opportunity to optimize modifiable factors within local systems of care to improve OHCA outcomes.

The influence of age and chronic medical conditions on neurological outcomes in out of hospital cardiac arrest.

AIM: It is unknown whether older patients with out of hospital cardiac arrest (OHCA) have worse outcomes because of aging itself, or because age can be a marker for overall health status. We aimed to study the prognostic utility of age and pre-arrest comorbidities. METHODS: We conducted a retrospective cohort study, reviewing electronic health records of all adults treated for non-traumatic OHCA in the University of Michigan Emergency Department (N=588). Primary covariates included age, Charlson Comorbidity Index (CCI), and a combined Charlson-age index. The primary dichotomized outcome was favorable neurological outcome (cerebral performance category, 1-2), evaluated by logistic regressions. RESULTS: Dementia (p=0.01), witnessed arrest (p=0.03), bystander CPR (p<0.001), presenting rhythm (p<0.001), and mild therapeutic hypothermia (p<0.001) were associated with the primary outcome. Increasing age (unadjusted OR for each decade of life, 95% CI: 0.78, 0.70-0.88; adjusted 0.79, 0.67-0.94) was negatively associated with likelihood of a favorable neurological outcome. CCI and combined Charlson-age index significantly predicted outcome in the unadjusted, but not adjusted analysis. Composite variables were stronger predictors in patients with shockable than non-shockable presenting rhythms (interaction terms: age and rhythm [p=0.004], CCI and rhythm [p=0.01]). CONCLUSION: Age, but not CCI, was significantly associated with less favorable neurological outcomes in patients with OHCA after adjusting important covariates. Age appears to be an independent predictor of prognosis rather than a marker for comorbidity.

Risk factors related to transfusion requirements in patients undergoing implantation of ventricular assist devices.

OBJECTIVE: The identification of transfusion risk factors in patients receiving left ventricular assist devices to allow for targeted use of blood conservation strategies and improved blood utilization. DESIGN: This is a retrospective analysis of prospectively collected data between April 2009 and June 2012. Linear regression was used to determine factors associated with increased transfusion. Logistic regression was used to determine factors that were associated with more than the median number of units transfused. SETTING: Single center, university hospital. PARTICIPANTS: Patients (n=144) who underwent left ventricular assist device implantation. INTERVENTION: Transfused blood product data for the day of surgery and for 3 days after were obtained from the blood bank. MEASUREMENTS AND MAIN RESULTS: Beta-blockers were associated with 1.7±0.65 fewer red blood cell (RBC) units and 2.2±0.7 fewer fresh frozen plasma units transfused. Each year of older age was associated with 0.113±0.023 units of RBC, 0.543±0.101 platelet, and 0.098±0.017 plasma units transfused. International normalized ratio was associated with more platelet transfusion (20.813±5.757 units per 1.0 increase), but not with plasma or RBC transfusion. Lower platelet counts were associated with both platelet (-0.045±0.019 units per 10,000 µL(-1)) and plasma transfusions (-0.011±0.004). Myocardial infarction was associated with increased RBC and plasma transfusion, and cardiogenic shock was associated with increased platelet transfusions, but nitrate use was associated with reduced platelet transfusion. CONCLUSION: Beta-blockers may be a modifiable factor to decrease transfusions. The association between international normalized ratio and platelet transfusions suggests that better determination of the type of coagulopathy may promote more appropriate transfusions.

Impact of adding aspirin to beta-blocker and statin in high-risk patients undergoing major vascular surgery.

BACKGROUND: Beta-blockers (BB) and statins (S) independently have been shown to reduce perioperative mortality and myocardial infarction (MI) in patients undergoing vascular surgery. In this study we evaluated the benefits of adding aspirin (A) to BB and S (ABBS), with/without angiotensin-converting enzyme inhibitor (ACE-I) on postoperative outcome in high-risk patients undergoing major vascular surgery. METHODS: Analysis of consecutive patients undergoing elective vascular surgery at the University of Michigan Cardiovascular Center was performed. Univariate and multivariate analyses were done using cardiac risk index [Revised Cardiac Risk Index (RCRI), coronary artery disease (CAD), insulin-dependent diabetes mellitus (IDDM), cerebral vascular disease, renal dysfunction, congestive heart failure, and major surgery]; pulmonary disease; and A, BB, S (ABBS)±ACE-I use. Baseline clinical characteristics and medication were adjusted using propensity scores. Endpoints were bleeding, 30-day MI, stroke, and 12-month mortality. RESULTS: Between 2003 and 2010, 4,149 arterial procedures were performed, 819 of which were risk stratified as RCRI≥3. The incidence of MI was 3-fold lower (2.5% vs. 7.8%, OR 0.31, 95% CI 0.15-0.61, P=0.001) in ABBS±ACE-I (n=513) as compared with non-ABBS±ACE-I (n=306). The 12-month mortality was 8-fold lower in ABBS±ACE-I as compared non-ABBS±ACE-I (5.9% vs. 37.5%, HR 0.13, 95% CI 0.08-0.20, P<0.0001). After adjustment for the propensity to use various therapies, A (HR 0.35, 95% CI 0.24-0.53, P<0.0001), BB (HR 0.65, 95% CI 0.43-1.0, P=0.05), and S (HR 0.36, 95% CI 0.25-0.53, P<0.0001) remained associated with improved 12-month survival. ACE-I use (HR 0.80, 95% CI 0.54-1.19, P=0.27) was not predictive. Aspirin did not predict severe/moderate bleeding. CONCLUSIONS: In high-risk patients undergoing major vascular surgery, ABBS therapy has superior 30-day and 12-month risk reduction benefits for MI, stroke, and mortality as compared with A, BB, or S independently. ACE-I did not demonstrate additional risk-reduction benefits.