Finding acute coronary syndrome with serial troponin testing for rapid assessment of cardiac ischemic symptoms (FAST-TRAC): a study protocol.

OBJECTIVE: To determine the utility of a highly sensitive troponin assay when utilized in the emergency department. METHODS: The FAST-TRAC study prospectively enrolled >1,500 emergency department patients with suspected acute coronary syndrome within 6 hours of symptom onset and 2 hours of emergency department presentation. It has several unique features that are not found in the majority of studies evaluating troponin. These include a very early presenting population in whom prospective data collection of risk score parameters and the physician's clinical impression of the probability of acute coronary syndrome before any troponin data were available. Furthermore, two gold standard diagnostic definitions were determined by a pair of cardiologists reviewing two separate data sets; one that included all local troponin testing results and a second that excluded troponin testing so that diagnosis was based solely on clinical grounds. By this method, a statistically valid head-to-head comparison of contemporary and high sensitivity troponin testing is obtainable. Finally, because of a significant delay in sample processing, a unique ability to define the molecular stability of various troponin assays is possible. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00880802.

Rationale and Strategies for Development of an Optimal Bundle of Management for Cardiac Arrest.

OBJECTIVES: To construct a highly detailed yet practical, attainable roadmap for enhancing the likelihood of neurologically intact survival following sudden cardiac arrest. DESIGN SETTING AND PATIENTS: Population-based outcomes following out-of-hospital cardiac arrest were collated for 10 U.S. counties in Alaska, California, Florida, Ohio, Minnesota, Utah, and Washington. The 10 identified emergency medical services systems were those that had recently reported significant improvements in neurologically intact survival after introducing a more comprehensive approach involving citizens, hospitals, and evolving strategies for incorporating technology-based, highly choreographed care and training. Detailed inventories of in-common elements were collated from the ten 9-1-1 agencies and assimilated. For reference, combined averaged outcomes for out-of-hospital cardiac arrest occurring January 1, 2017, to February 28, 2018, were compared with concurrent U.S. outcomes reported by the well-established Cardiac Arrest Registry to Enhance Survival. INTERVENTIONS: Most commonly, interventions and components from the ten 9-1-1 systems consistently included extensive public cardiopulmonary resuscitation training, 9-1-1 system-connected smart phone applications, expedited dispatcher procedures, cardiopulmonary resuscitation quality monitoring, mechanical cardiopulmonary resuscitation, devices for enhancing negative intrathoracic pressure regulation, extracorporeal membrane oxygenation protocols, body temperature management procedures, rapid cardiac angiography, and intensive involvement of medical directors, operational and quality assurance officers, and training staff. MEASUREMENTS AND MAIN RESULTS: Compared with Cardiac Arrest Registry to Enhance Survival (n = 78,704), the cohorts from the 10 emergency medical services agencies examined (n = 2,911) demonstrated significantly increased likelihoods of return of spontaneous circulation (mean 37.4% vs 31.5%; p < 0.001) and neurologically favorable hospital discharge, particularly after witnessed collapses involving bystander cardiopulmonary resuscitation and shockable cardiac rhythms (mean 10.7% vs 8.4%; p < 0.001; and 41.6% vs 29.2%; p < 0.001, respectively). CONCLUSIONS: The likelihood of neurologically favorable survival following out-of-hospital cardiac arrest can improve substantially in communities that conscientiously and meticulously introduce a well-sequenced, highly choreographed, system-wide portfolio of both traditional and nonconventional approaches to training, technologies, and physiologic management. The commonalities found in the analyzed systems create a compelling case that other communities can also improve out-of-hospital cardiac arrest outcomes significantly by conscientiously exploring and adopting similar bundles of system organization and care.

Long-Term Prognostic Value of Gasping During Out-of-Hospital Cardiac Arrest.

BACKGROUND: Gasping is a natural reflex that enhances oxygenation and circulation during cardiopulmonary resuscitation (CPR). OBJECTIVES: This study sought to assess the relationship between gasping during out-of-hospital cardiac arrest and 1-year survival with favorable neurological outcomes. METHODS: The authors prospectively collected incidence of gasping on all evaluable subjects in a multicenter, randomized, controlled, National Institutes of Health-funded out-of-hospital cardiac arrest clinical trial from August 2007 to July 2009. The association between gasping and 1-year survival with favorable neurological function, defined as a Cerebral Performance Category (CPC) score ≤2 was estimated using multivariable logistic regression. RESULTS: The rates of 1-year survival with a CPC score of ≤2 were 5.4% (98 of 1,827) overall, and 20% (36 of 177) and 3.7% (61 of 1,643) for individuals with and without spontaneous gasping or agonal respiration during CPR, respectively. In multivariable analysis, 1-year survival with CPC ≤2 was independently associated with younger age (odds ratio [OR] for 1 SD increment 0.57; 95% confidence interval [CI]: 0.43 to 0.76), gasping during CPR (OR: 3.94; 95% CI: 2.09 to 7.44), shockable initial recorded rhythm (OR: 16.50; 95% CI: 7.40 to 36.81), shorter CPR duration (OR: 0.31; 95% CI: 0.19 to 0.51), lower epinephrine dosage (OR: 0.47; 95% CI: 0.25 to 0.87), and pulmonary edema (OR: 3.41; 95% CI: 1.53 to 7.60). Gasping combined with a shockable initial recorded rhythm had a 57-fold higher OR (95% CI: 23.49 to 136.92) of 1-year survival with CPC ≤2 versus no gasping and no shockable rhythm. CONCLUSIONS: Gasping during CPR was independently associated with increased 1-year survival with CPC ≤2, regardless of the first recorded rhythm. These findings underscore the importance of not terminating resuscitation prematurely in gasping patients and the need to routinely recognize, monitor, and record data on gasping in all future cardiac arrest trials and registries.

The association of health status and providing consent to continued participation in an out-of-hospital cardiac arrest trial performed under exception from informed consent.

OBJECTIVES: Emergency medical research performed under federal regulation 21 § CFR 50.24 provides a means to protect human subjects and investigate novel time-sensitive treatments. Although prospective individual consent is not required for studies conducted under this regulation, consent from a legally authorized representative (LAR) or the patient at the earliest feasible opportunity is required to obtain short- and long-term outcome data. The objective of this study was to determine which demographic, cardiac arrest, and patient outcome characteristics predicted the likelihood of obtaining informed consent following enrollment under exception from informed consent in a multicenter cardiac arrest study. METHODS: This investigation was an analysis of data collected during a multisite, randomized, controlled, out-of-hospital cardiac arrest clinical trial performed under 21 § CFR 50.24. Research personnel attempted to obtain informed consent from LARs and subjects for medical records review of primary outcome data, as well as consent for neurologic outcome assessments up to 1 year post-cardiac arrest. Hospital discharge and neurologic status were obtained from public records and/or medical records up until the time consent was formally denied, in accordance with federal regulations and guidance. Local institutional review boards also allowed medical records review for cases where consent was neither obtained nor declined despite multiple consent attempts. Patient demographic, cardiac arrest, and clinical outcome characteristics were analyzed in univariate multinomial regression models, with consent status (obtained, denied, neither obtained nor denied) as the dependent variable. A multivariate multinomial logistic regression was then performed. An exploratory secondary analysis following the same process was performed after assigning patients who neither consented nor declined to the declined consent group. RESULTS: Among a total study population of 1,655 cardiac arrest subjects, 457 were transported and had consent attempted (27.6%). The survival status and neurologic function at the time of hospital discharge were known in 440 of 457 (96%) subjects. In the multivariate analysis, initial rhythm of ventricular fibrillation/ventricular tachycardia (VF/VT) and survival with good neurologic outcome were strong predictors of obtaining consent (odds ratio [OR] = 3.15, 95% confidence interval [CI] = 1.73 to 5.75; OR = 7.64, 95% CI = 2.28 to 25.63, respectively). The exploratory secondary analysis also showed initial rhythm of VF/VT and survival with good neurologic outcome as strong predictors of obtaining consent (OR = 1.86, 95% CI = 1.17 to 2.95; OR = 4.52, 95% CI = 2.21 to 9.26, respectively). CONCLUSIONS: Initial arrest rhythm and survival with good neurologic outcome were highly predictive of obtaining consent in this cardiac arrest trial. This phenomenon could result in underrepresentation of outcome data in the study arm with the worse outcome and represents a significant potential confounder in studies performed under 21 § CFR 50.24. Future revisions to the exception from informed consent regulations should allow access to critical survival data recorded as part of standard documentation, regardless of patient consent status.

One-year outcomes of out-of-hospital administration of intravenous glucose, insulin, and potassium (GIK) in patients with suspected acute coronary syndromes (from the IMMEDIATE [Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency Care] Trial).

The Immediate Myocardial Metabolic Enhancement During Initial Assessment and Treatment in Emergency care Trial of very early intravenous glucose-insulin-potassium (GIK) for acute coronary syndromes (ACS) in out-of-hospital emergency medical service (EMS) settings showed 80% reduction in infarct size at 30 days, suggesting potential longer-term benefits. Here we report 1-year outcomes. Prespecified 1-year end points of this randomized, placebo-controlled, double-blind, effectiveness trial included all-cause mortality and composites including cardiac arrest, mortality, or hospitalization for heart failure (HF). Of 871 participants randomized to GIK versus placebo, death occurred within 1 year in 11.6% versus 13.5%, respectively (unadjusted hazard ratio [HR] 0.83, 95% confidence interval [CI] 0.57 to 1.23, p = 0.36). The composite of cardiac arrest or 1-year mortality was 12.8% versus 17.0% (HR 0.71, 95% CI 0.50 to 1.02, p = 0.06). The composite of hospitalization for HF or mortality within 1 year was 17.2% versus 17.2% (HR 0.98, 95% CI 0.70 to 1.37, p = 0.92). The composite of mortality, cardiac arrest, or HF hospitalization within 1 year was 18.1% versus 20.4% (HR 0.85, 95% CI 0.62 to 1.16, p = 0.30). In patients presenting with suspected ST elevation myocardial infarction, HRs for 1-year mortality and the 3 composites were, respectively, 0.65 (95% CI 0.33 to 1.27, p = 0.21), 0.52 (95% CI 0.30 to 0.92, p = 0.03), 0.63 (95% CI 0.35 to 1.16, p = 0.14), and 0.51 (95% CI 0.30 to 0.87, p = 0.01). In patients with suspected acute coronary syndromes, serious end points generally were lower with GIK than placebo, but the differences were not statistically significant. However, in those with ST elevation myocardial infarction, the composites of cardiac arrest or 1-year mortality, and of cardiac arrest, mortality, or HF hospitalization within 1 year, were significantly reduced.

Treatment of non-traumatic out-of-hospital cardiac arrest with active compression decompression cardiopulmonary resuscitation plus an impedance threshold device.

BACKGROUND: A recent out-of-hospital cardiac arrest (OHCA) clinical trial showed improved survival to hospital discharge (HD) with favorable neurologic function for patients with cardiac arrest of cardiac origin treated with active compression decompression cardiopulmonary resuscitation (CPR) plus an impedance threshold device (ACD+ICD) versus standard (S) CPR. The current analysis examined whether treatment with ACD+ITD is more effective than standard (S-CPR) for all cardiac arrests of non-traumatic origin, regardless of the etiology. METHODS: This is a secondary analysis of data from a randomized, prospective, multicenter, intention-to-treat, OHCA clinical trial. Adults with presumed non-traumatic cardiac arrest were enrolled and followed for one year post arrest. The primary endpoint was survival to hospital discharge (HD) with favorable neurologic function (Modified Rankin Scale score ≤ 3). RESULTS: Between October 2005 and July 2009, 2738 patients were enrolled (S-CPR=1335; ACD+ITD=1403). Survival to HD with favorable neurologic function was greater with ACD+ITD compared with S-CPR: 7.9% versus 5.7%, (OR 1.42, 95% CI 1.04, 1.95, p=0.027). One-year survival was also greater: 7.9% versus 5.7%, (OR 1.43, 95% CI 1.04, 1.96, p=0.026). Nearly all survivors in both groups had returned to their baseline neurological function by one year. Major adverse event rates were similar between groups. CONCLUSIONS: Treatment of out-of-hospital non-traumatic cardiac arrest patients with ACD+ITD resulted in a significant increase in survival to hospital discharge with favorable neurological function when compared with S-CPR. A significant increase survival rates was observed up to one year after arrest in subjects treated with ACD+ITD, regardless of the etiology of the cardiac arrest.

Out-of-hospital administration of intravenous glucose-insulin-potassium in patients with suspected acute coronary syndromes: the IMMEDIATE randomized controlled trial.

CONTEXT: Laboratory studies suggest that in the setting of cardiac ischemia, immediate intravenous glucose-insulin-potassium (GIK) reduces ischemia-related arrhythmias and myocardial injury. Clinical trials have not consistently shown these benefits, possibly due to delayed administration. OBJECTIVE: To test out-of hospital emergency medical service (EMS) administration of GIK in the first hours of suspected acute coronary syndromes (ACS). DESIGN, SETTING, AND PARTICIPANTS: Randomized, placebo-controlled, double-blind effectiveness trial in 13 US cities (36 EMS agencies), from December 2006 through July 31, 2011, in which paramedics, aided by electrocardiograph (ECG)-based decision support, randomized 911 (871 enrolled) patients (mean age, 63.6 years; 71.0% men) with high probability of ACS. INTERVENTION: Intravenous GIK solution (n = 411) or identical-appearing 5% glucose placebo (n = 460) administered by paramedics in the out-of-hospital setting and continued for 12 hours. MAIN OUTCOME MEASURES: The prespecified primary end point was progression of ACS to myocardial infarction (MI) within 24 hours, as assessed by biomarkers and ECG evidence. Prespecified secondary end points included survival at 30 days and a composite of prehospital or in-hospital cardiac arrest or in-hospital mortality, analyzed by intent-to-treat and by presentation with ST-segment elevation. RESULTS: There was no significant difference in the rate of progression to MI among patients who received GIK (n = 200; 48.7%) vs those who received placebo (n = 242; 52.6%) (odds ratio [OR], 0.88; 95% CI, 0.66-1.13; P = .28). Thirty-day mortality was 4.4% with GIK vs 6.1% with placebo (hazard ratio [HR], 0.72; 95% CI, 0.40-1.29; P = .27). The composite of cardiac arrest or in-hospital mortality occurred in 4.4% with GIK vs 8.7% with placebo (OR, 0.48; 95% CI, 0.27-0.85; P = .01). Among patients with ST-segment elevation (163 with GIK and 194 with placebo), progression to MI was 85.3% with GIK vs 88.7% with placebo (OR, 0.74; 95% CI, 0.40-1.38; P = .34); 30-day mortality was 4.9% with GIK vs 7.7% with placebo (HR, 0.63; 95% CI, 0.27-1.49; P = .29). The composite outcome of cardiac arrest or in-hospital mortality was 6.1% with GIK vs 14.4% with placebo (OR, 0.39; 95% CI, 0.18-0.82; P = .01). Serious adverse events occurred in 6.8% (n = 28) with GIK vs 8.9% (n = 41) with placebo (P = .26). CONCLUSIONS: Among patients with suspected ACS, out-of-hospital administration of intravenous GIK, compared with glucose placebo, did not reduce progression to MI. Compared with placebo, GIK administration was not associated with improvement in 30-day survival but was associated with lower rates of the composite outcome of cardiac arrest or in-hospital mortality. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00091507.

Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomised trial.

BACKGROUND: Active compression-decompression cardiopulmonary resuscitation (CPR) with decreased intrathoracic pressure in the decompression phase can lead to improved haemodynamics compared with standard CPR. We aimed to assess effectiveness and safety of this intervention on survival with favourable neurological function after out-of-hospital cardiac arrest. METHODS: In our randomised trial of 46 emergency medical service agencies (serving 2·3 million people) in urban, suburban, and rural areas of the USA, we assessed outcomes for patients with out-of-hospital cardiac arrest according to Utstein guidelines. We provisionally enrolled patients to receive standard CPR or active compression-decompression CPR with augmented negative intrathoracic pressure (via an impedance-threshold device) with a computer-generated block randomisation weekly schedule in a one-to-one ratio. Adults (presumed age or age ≥18 years) who had a non-traumatic arrest of presumed cardiac cause and met initial and final selection criteria received designated CPR and were included in the final analyses. The primary endpoint was survival to hospital discharge with favourable neurological function (modified Rankin scale score of ≤3). All investigators apart from initial rescuers were masked to treatment group assignment. This trial is registered with ClinicalTrials.gov, number NCT00189423. FINDINGS: 2470 provisionally enrolled patients were randomly allocated to treatment groups. 813 (68%) of 1201 patients assigned to the standard CPR group (controls) and 840 (66%) of 1269 assigned to intervention CPR received designated CPR and were included in the final analyses. 47 (6%) of 813 controls survived to hospital discharge with favourable neurological function compared with 75 (9%) of 840 patients in the intervention group (odds ratio 1·58, 95% CI 1·07-2·36; p=0·019]. 74 (9%) of 840 patients survived to 1 year in the intervention group compared with 48 (6%) of 813 controls (p=0·03), with equivalent cognitive skills, disability ratings, and emotional-psychological statuses in both groups. The overall major adverse event rate did not differ between groups, but more patients had pulmonary oedema in the intervention group (94 [11%] of 840) than did controls (62 [7%] of 813; p=0·015). INTERPRETATION: On the basis of our findings showing increased effectiveness and generalisability of the study intervention, active compression-decompression CPR with augmentation of negative intrathoracic pressure should be considered as an alternative to standard CPR to increase long-term survival after cardiac arrest. FUNDING: US National Institutes of Health grant R44-HL065851-03, Advanced Circulatory Systems.

Comparison of traditional versus video laryngoscopy in out-of-hospital tracheal intubation.

BACKGROUND: Out-of-hospital tracheal intubation is controversial because of questions regarding its safety as well as its impact on patient care. Factors contributing to the controversy include failed intubations, number of attempts required, prolonged periods without ventilation, and misplaced tracheal tubes. However, the most important factors are the decision-making and clinical skills of the intubator. Unfortunately, the limited number of outcome studies adds to the controversy. New technology, the video laryngoscope, has been introduced to facilitate tracheal intubation. At least one model of video laryngoscope (GlideScope Ranger) has been designed for out-of-hospital use. In an effort to assess the effect this technology might have on out-of-hospital intubation, a study comparing traditional laryngoscopy (TL) versus video laryngoscopy (VL) was performed. The study endpoint was the number of attempts to achieve intubation. Data were also collected on time to intubate, nonventilated periods, unrecognized misplaced tubes, and complications of the procedure. METHODS: Data were collected on 300 consecutive patients, 6 years of age or older, weighing at least 20 kg, who were intubated using TL. They were compared with data on 315 patients who were intubated using VL. All intubations were confirmed by visualization where possible, auscultation, misting, and capnography. In addition, all were continuously monitored by capnography. RESULTS: The average time to intubate in the VL group was 21 seconds (range 8-43 seconds) versus 42 seconds (range 28-90 seconds) in the TL group. The average number of attempts was 1.2 (range 1-3) in the VL group versus 2.3 (range 1-4) in the TL group. Successful intubation was 97% in the VL group versus 95% in the TL group. There were no unrecognized misplaced tubes in either group. For failed intubations, an alternative airway was successful in 99% of the VL group and 99% of the TL group. Maximum nonventilated time during any one intubation attempt was 37 seconds in the VL group and 55 seconds in the TL group. CONCLUSIONS: The numbers of attempts were significantly reduced in the VL group. This suggests that the use of VL has a positive effect on the number of attempts to achieve tracheal intubation.

Prehospital management of acute tachyarrhythmias.

Arrhythmias are commonly encountered by emergency medical services (EMS) personnel. The potential seriousness of acute symptomatic arrhythmias necessitates thorough up-to-date training of EMS personnel. The three most common acute tachyarrhythmias, not linked to cardiac arrest, that are observed outside the hospital are paroxysmal supraventricular tachycardia (PSVT), atrial fibrillation with rapid ventricular response (RAF), and perfusing ventricular tachycardia (VT). Ideally, these tachyarrhythmias should be operationally defined in a manner that simplifies, particularly for EMS providers, their diagnosis and treatment. The authors recommend referring to these rhythms as regular narrow-complex tachycardia (presumed PSVT), irregularly irregular narrow-complex tachycardia (presumed RAF), or regular wide-complex tachycardia (presumed VT or aberrantly conducted PSVT). Although the value of treatments such as cardioversion is widely understood, the benefit from others, such as lidocaine, is unclear. Current preferences, recommendations, and concerns regarding the treatment of most arrhythmias outside the hospital reflect the dichotomy that sometimes exists between available evidence and actual practice.

Prehospital management of cardiac arrest: how useful are vasopressor and antiarrhythmic drugs?

Out-of-hospital resuscitation protocols for patients suffering cardiac arrest have historically included cardiopulmonary resuscitation, defibrillation, and rapid transport to a hospital. For many years, use of drugs to improve myocardial perfusion or to correct arrhythmias that occur during cardiac arrest has been part of prehospital efforts to revive patients in ventricular tachycardia or ventricular fibrillation. Use of some of these drugs, however, may be based more on tradition than on well-documented evidence of efficacy. The authors reviewed pertinent data on the vasopressors epinephrine and vasopressin and the antiarrhythmics amiodarone and lidocaine to evaluate the usefulness of these drugs in cardiac arrest. They found little clinical data supporting the prehospital use of lidocaine in cardiac arrest, and despite a great deal of laboratory and clinical data addressing the efficacy of epinephrine, there is no large, randomized, controlled clinical trial supporting its use. Data on amiodarone and vasopressin support the use of these drugs in out-of-hospital resuscitation efforts.