Oblique-axis vs. short-axis view in ultrasound-guided central venous catheterization.

BACKGROUND: Ultrasound (US) guidance during central venous catheterization (CVC) reduces complications and improves success rates compared to landmark-guided techniques. A novel "oblique view" (US transducer held at approximately 45° with respect to the target vessel) has been suggested to be superior to the standard short-axis approach usually used during US-guided CVC. OBJECTIVES: The purpose of this study was to compare the rates of posterior vessel wall puncture (PVWP) between the short-axis and oblique-axis approaches to US-guided CVC. METHODS: This was a prospective observational trial of emergency medicine residents and attending physicians, using gelatin models to simulate short-axis and oblique-axis US-guided CVC. Participants were blinded to the primary outcome of PVWP. Data collected included year in training/practice, number of central lines placed, time to successful "flash," and self-reported confidence of needle tip position using a Likert scale. After CVC simulation, models were deconstructed and inspected for PVWP. RESULTS: The rate of PVWP was 14.7% using short axis vs. 2.9% using oblique axis, resulting in a difference of 11.8% (95% confidence interval [CI] -4.7-28.3%, p = 0.10) and an odds ratio of 0.2 (95% CI 0.004-1.79). This difference was not statistically significant (p = 0.10). Mean time to flash was 11.9 s using short axis, and 15.4 s using oblique axis (p = 0.14). Confidence in needle tip location was 3.63 using short axis, and 4.58 using oblique axis (p < 0.001). CONCLUSIONS: We found decreased PVWP using the oblique axis approach, though the difference was not statistically significant, and participants felt more confident in their needle tip location using the oblique axis view. Further research into the potential benefits of the oblique axis approach is warranted.

Regional differences in emergency medical services use for patients with acute stroke (findings from the National Hospital Ambulatory Medical Care Survey Emergency Department Data File).

BACKGROUND: Our objectives were to describe the proportion of stroke patients who arrive by ambulance nationwide and to examine regional differences and factors associated with the mode of transport to the emergency department (ED). METHODS: Patients with a primary discharge diagnosis of stroke based on previously validated International Classification of Disease, 9th revision codes were abstracted from the National Hospital Ambulatory Medical Care Survey for the years 2007 to 2009. We excluded subjects<18 years of age and those with missing data. Using logistic regression, we identified independent predictors of arrival by ambulance to the ED. RESULTS: Overall, 566 patients met the entry criteria, representing 2,153,234 patient records nationally, based on 2010 US census data. Of these, 50.4% arrived by ambulance. After adjustment for potential confounders, age was associated with use of an ambulance. In addition, patients residing in the west and south had lower odds of arriving by ambulance for stroke when compared to northeast (South: odds ratio [OR] 0.45 and 95% confidence interval [CI] 0.26-0.76; West: OR 0.45 and 95% CI 0.25-0.84; Midwest: OR 0.56 and 95% CI 0.31-1.01). Compared to the Medicare population, privately insured and self-insured patients had lower odds of arriving by ambulance (OR for private insurance 0.48 and 95% CI 0.28-0.84; OR for self-payers 0.36 and 95% CI 0.14-0.93). Gender, race, urban or rural location of ED, and safety net status was not independently associated with ambulance use. CONCLUSIONS: Patients with stroke arrive by ambulance more frequently in the Northeast than in other regions of the United States. Identifying reasons for this difference may be useful in improving stroke care.

Antimicrobial resistance in uncomplicated urinary tract infections in 3 California EDs.

BACKGROUND: Increased trimethoprim/sulfamethoxazole (TMP/SMX) resistance has led to changes in empiric treatment of female urinary tract infections (UTI) in the emergency department (ED), particularly increased use of fluoroquinolones (Acad Emerg Med.2009;16(6):500-507). Whether prescribing changes have affected susceptibility in uropathogens is unclear. Using narrow-spectrum agents and therapy tailored to local susceptibilities remain important goals. OBJECTIVE: The primary goal of this study is to characterize the susceptibility patterns of uropathogens among ambulatory female ED patients with UTI. Its secondary goal is to identify demographic or clinical factors predictive of resistance to narrow-spectrum agents. METHODS: This was a cross-sectional study of women with suspected UTI referred to a trial of computer kiosk-aided treatment of UTI in 3 Northern California EDs. Demographic and clinical data were gathered from the kiosk and chart, and features associated with resistance were identified by bivariate and multivariable regression analysis. RESULTS: Two hundred eighty-three participants, aged 15 to 84 years, were diagnosed with UTI and cultured. One hundred thirty-five (48%) of cultures were positive, with full susceptibilities reported (81% Escherichia coli). Only 2 isolates (1.5%) were fluoroquinolone resistant. Resistance to TMP/SMX was 18%, to nitrofurantoin 5%, and to cefazolin 4%. Seventy-four percent were sensitive to all 3 narrow-spectrum agents. Resistance to narrow-spectrum agents did not vary significantly by diagnosis, age, recent UTI, or any clinical or demographic factors; but overall, there was a trend toward lower resistance rates in our population than in our hospitals' published antibiograms. CONCLUSION: In our population of ambulatory female ED patients, resistance to TMP/SMX is just below the 20% threshold that the Infectious Disease Society of America recommends for continued empiric use (Clin Infect Dis.1999;29(4):745-758, Clin Infect Dis.2011;52(5):e103-120), whereas resistance to other narrow-spectrum agents, such as nitrofurantoin and cephalexin, may be lower than published antibiograms for our sites. Fluoroquinolone resistance remains very low.

Constipation in a 7-year-old boy: congenital band causing a strangulated small bowel and pulseless electrical activity.

BACKGROUND: Constipation in pediatric patients is a common diagnosis in the emergency department (ED) and may occasionally arise from a significant underlying illness. OBJECTIVE: To discuss a rare cause of constipation that led to a strangulated small bowel and cardiac arrest. CASE REPORT: A 7-year-old boy presented in pulseless electrical activity. The patient had been seen in the ED 2 days prior with the complaint of abdominal pain, which was diagnosed as constipation. The boy had emigrated from Mexico 18 months earlier. The patient was resuscitated in the ED and taken emergently to the operating room. During surgery he was discovered to have a congenital abdominal adhesive band that led to a strangulated small bowel. He suffered subsequent multi-organ failure, including hypoxic ischemic encephalopathy, and was hospitalized for 5 months. One month after discharge he was improving and being followed by multiple providers. CONCLUSION: Congenital adhesive bands, although rare, may be life-threatening anomalies. We present this case to increase awareness of this condition among emergency physicians.

Hypertensive encephalopathy presenting as status epilepticus in a three year old.

BACKGROUND: Hypertensive encephalopathy is one of the few neurologic emergencies in which prompt diagnosis and treatment can prevent permanent neurological damage. This syndrome is rarely seen in children. OBJECTIVES: To discuss the recognition of hypertensive encephalopathy as a cause of acute neurological changes in children. CASE REPORT: We present the case of a 3-year-old boy who presented to the Emergency Department with seizures due to hypertensive encephalopathy. A review of the literature on the subject follows the case report. CONCLUSIONS: Hypertensive encephalopathy is a rare cause of acute neurological changes in children that can cause permanent damage if not recognized early. This case illustrates the importance of considering this syndrome as a potential cause of neurological symptoms, especially as neuroimaging can initially be misleading.

Use of a ß-hCG discriminatory zone with bedside pelvic ultrasonography.

STUDY OBJECTIVE: We seek to assess the performance of the ß human chorionic gonadotropin (ß-hCG) "discriminatory zone" when using bedside pelvic ultrasonography in the evaluation of symptomatic pregnant emergency department (ED) patients. METHODS: This was a cross-sectional study of bedside pelvic ultrasonography performed on consecutive pregnant patients in the first trimester who presented to the ED with abdominal pain or vaginal bleeding. Patients received pelvic ultrasonography, serum ß-hCG testing, and blinded formal radiologic ultrasonography. All patients were followed for 8 weeks to determine outcomes. The sensitivity and specificity of a discriminatory ß-hCG level of 3,000 mIU/mL for the diagnosis of ectopic pregnancy were calculated for patients without an intrauterine pregnancy visualized by bedside ultrasonography. RESULTS: Thirty-six faculty physicians performed bedside pelvic ultrasonography on 256 patients. There were 161 cases with a confirmed visualizable intrauterine pregnancy and 29 ectopic pregnancies. Bedside ultrasonography identified 115 intrauterine pregnancies. The range of ß-hCG for cases of confirmed visualizable intrauterine pregnancy with a nondiagnostic bedside ultrasonography was 15 mIU/mL to 123,368 mIU/mL (median 6,633; interquartile range 1,551 to 32,699). For patients with nondiagnostic bedside ultrasonography, using a discriminatory ß-hCG level of 3,000 mIU/mL to further assess for ectopic pregnancy showed sensitivity of 35% (95% confidence interval [CI] 18% to 54%) and specificity of 58% (95% CI 48% to 67%). Finally, the overall sensitivity of bedside pelvic ultrasonography for the detection of intrauterine pregnancy was 71% (95% CI 63% to 78%), and the specificity was 99% (95% CI 94% to 100%). CONCLUSION: When bedside pelvic ultrasonography does not demonstrate an intrauterine pregnancy, serum ß-hCG level is not helpful in differentiating intrauterine from ectopic pregnancy in symptomatic ED patients.

A severe sore throat in a middle-aged man: calcific tendonitis of the longus colli tendon.

BACKGROUND: Neck pain is a common presentation to the Emergency Department (ED), requiring appropriate evaluation to exclude serious pathology. OBJECTIVES: To review an atypical clinical presentation of neck pain and to distinguish this case and its associated radiographic features from more common clinical entities. CASE REPORT: We present an ED case of calcific tendonitis of the longus coli muscle. SUMMARY: Acute calcific retropharyngeal tendinitis is a rare, benign etiology of non-traumatic neck pain that is poorly recognized and often mistaken for other conditions secondary to infection or trauma. The importance of this disorder, as well as a review of the literature on the subject, is presented.

Emergency physician ultrasonography for evaluating patients at risk for ectopic pregnancy: a meta-analysis.

STUDY OBJECTIVE: Ectopic pregnancy is a common concern in emergency departments (EDs) and remains the leading cause of first-trimester mortality. Pelvic ultrasonography by emergency physicians has been investigated as a diagnostic test for ectopic pregnancy. We present a meta-analysis of the use of emergency physician ultrasonography in the evaluation of patients at risk of ectopic pregnancy. METHODS: A structured search was performed of both MEDLINE and EMBASE. Inclusion criteria were that (1) the study reported original research on ED patients at risk for ectopic pregnancy; (2) an emergency physician performed and interpreted the initial pelvic ultrasonography; and (3) follow-up was conducted on all patients. Sensitivity was defined as the proportion of patients with ectopic pregnancy for which ED ultrasonography demonstrated no intrauterine pregnancy. A random-effects model was used to obtain summary test characteristics. RESULTS: The initial search showed 576 publications, abstract review yielded 60 with potential relevance, and 10 studies were included. There was a total of 2,057 patients, of whom 152 (7.5%) had ectopic pregnancy. The pooled sensitivity estimate was 99.3% (95% confidence interval [CI] 96.6% to 100%), negative predictive value was 99.96% (95% CI 99.6% to 100%), and negative likelihood ratio was 0.08 (95% CI 0.025 to 0.25), all without significant heterogeneity. CONCLUSION: The results of this meta-analysis suggest that in a wide variety of clinical settings, the use of bedside ultrasonography performed by emergency physicians as a diagnostic test for ectopic pregnancy provides excellent sensitivity and negative predictive value. Visualization of an intrauterine pregnancy by an emergency physician is generally sufficient to rule out ectopic pregnancy.

A survey of bedside ultrasound use by emergency physicians in California.

OBJECTIVE: The purpose of this study was to investigate the current practice of emergency physician-performed bedside ultrasound examinations in California and to assess differences between academic and community practice. METHODS: We queried all emergency departments (EDs) in California to determine whether bedside ultrasound was used by emergency physicians. Among EDs that were using bedside ultrasound, we administered a survey to assess use patterns, credentialing criteria, and quality assurance (QA) programs. RESULTS: We contacted all eligible EDs (n = 293) by telephone and had a 100% response rate for our primary question: 101 EDs (34%) reported use of bedside ultrasound. Of these 101 EDs, 97 (96%) responded to the secondary survey, showing the following: (1) 48% of physicians at each site were credentialed to use ultrasound in at least 1 modality; (2) 70% of EDs used American College of Emergency Physicians (ACEP) criteria for credentialing guidelines; and (3) 33% had an ultrasound QA program. Comparing practice settings, 68% of academic departments used bedside ultrasound compared with 29% of community departments (difference, 39%; 95% confidence interval [CI], 23% to 54%; P < .0001). In academic departments, a mean of 60% of physicians were credentialed, compared with 41% in community EDs (difference, 19%; 95% CI, 2.5% to 35%; P = .036). CONCLUSIONS: Most California EDs do not use bedside ultrasound. Although most EDs using ultrasound report that they follow ACEP emergency ultrasound guidelines, most do not have a QA program as recommended by these guidelines. Compared with community EDs, academic EDs are more likely to use bedside ultrasound, have physicians credentialed in ultrasound use, and have QA programs.

Emergency Department Ultrasound Credentialing: a sample policy and procedure.

Emergency physician use of bedside ultrasound has increased dramatically over the last two decades. However, many emergency departments find it difficult to gain formal hospital credentialing for bedside sonography. We present the Emergency Department (ED) Ultrasound Credentialing Policy from the University of California, San Francisco. Although the American College of Emergency Physicians has published formal guidelines on this subject, they are not written in such a way that they are readily transcribed into a document suitable for review by credentialing committees and executive medical boards. Our policy details the background of emergency bedside ultrasound, the goals of its use, the scope of emergency physician sonography, credentialing criteria, and an example of a quality assurance program. We have not changed the components of the previously published guidelines. Rather, this document has withstood the rigor of our own credentialing process and is presented as an example in the hopes that it may help other EDs who seek credentialing in their institutions. This document is intended as a guideline for credentialing committees and will require alteration to meet the needs of each different hospital; however, the overall framework should allow for a less time-consuming process.

Root Cause Analysis of Ambulatory Adverse Drug Events That Present to the Emergency Department.

BACKGROUND: Adverse drug events (ADEs) among patients self-administering medications in home/community settings are a common cause of emergency department (ED) visits, but the causes of these ambulatory ADEs remain unclear. Root cause analysis, rarely applied in outpatient settings, may reveal the underlying factors that contribute to adverse events. STUDY OBJECTIVES: To elicit patient and provider perspectives on ambulatory ADEs and apply root cause analysis methodology to identify cross-cutting themes among these events. METHODS: Emergency department clinical pharmacists screened, identified, and enrolled a convenience sample of adult patients 18 years or older who presented to a single, urban, academic ED with symptoms or diagnoses consistent with suspected ADEs. Semistructured phone interviews were conducted with the patients and their providers. We conducted a qualitative analysis. We applied a prespecified version of the injury prevention framework (deductive coding), identifying themes relating to the agent (drug), host (patient), and environment (social and health systems). These themes were used to construct a root cause analysis for each ADE. RESULTS: From 18 interviews overall, we identified the following themes within the injury prevention framework. Agent factors included high-risk drugs, narrow therapeutic indices, and uncommon severe effects. Host factors included patient capacity or understanding of how to use medications, awareness of side effects, mistrust of the medical system, patients with multiple comorbidities, difficult risk-benefit assessments, and high health-care users. Environmental factors included lack of social support, and health systems issues included access to care, encompassing medication availability, access to specialists, and a lack of continuity and communication among prescribing physicians. Root cause analysis revealed multiple underlying factors relating to agent, host, and environment for each event. CONCLUSION: Patient and physician perspectives can inform a root cause analysis of ambulatory ADEs. Such methodology may be applied to understand the factors that contribute to ambulatory ADEs and serve as the formative work for future interventions improving home/community medication use.

Intensive care unit scoring systems outperform emergency department scoring systems for mortality prediction in critically ill patients: a prospective cohort study.

BACKGROUND: Multiple scoring systems have been developed for both the intensive care unit (ICU) and the emergency department (ED) to risk stratify patients and predict mortality. However, it remains unclear whether the additional data needed to compute ICU scores improves mortality prediction for critically ill patients compared to the simpler ED scores. METHODS: We studied a prospective observational cohort of 227 critically ill patients admitted to the ICU directly from the ED at an academic, tertiary care medical center. We compared Acute Physiology and Chronic Health Evaluation (APACHE) II, APACHE III, Simplified Acute Physiology Score (SAPS) II, Modified Early Warning Score (MEWS), Rapid Emergency Medicine Score (REMS), Prince of Wales Emergency Department Score (PEDS), and a pre-hospital critical illness prediction score developed by Seymour et al. (JAMA 2010, 304(7):747-754). The primary endpoint was 60-day mortality. We compared the receiver operating characteristic (ROC) curves of the different scores and their calibration using the Hosmer-Lemeshow goodness-of-fit test and visual assessment. RESULTS: The ICU scores outperformed the ED scores with higher area under the curve (AUC) values (p = 0.01). There were no differences in discrimination among the ED-based scoring systems (AUC 0.698 to 0.742; p = 0.45) or among the ICU-based scoring systems (AUC 0.779 to 0.799; p = 0.60). With the exception of the Seymour score, the ED-based scoring systems did not discriminate as well as the best-performing ICU-based scoring system, APACHE III (p = 0.005 to 0.01 for comparison of ED scores to APACHE III). The Seymour score had a superior AUC to other ED scores and, despite a lower AUC than all the ICU scores, was not significantly different than APACHE III (p = 0.09). When data from the first 24 h in the ICU was used to calculate the ED scores, the AUC for the ED scores improved numerically, but this improvement was not statistically significant. All scores had acceptable calibration. CONCLUSIONS: In contrast to prior studies of patients based in the emergency department, ICU scores outperformed ED scores in critically ill patients admitted from the emergency department. This difference in performance seemed to be primarily due to the complexity of the scores rather than the time window from which the data was derived.

Physician accuracy in interpreting potential ST-segment elevation myocardial infarction electrocardiograms.

BACKGROUND: With adoption of telemedicine, physicians are increasingly asked to diagnose ST-segment elevation myocardial infarctions (STEMIs) based on electrocardiograms (ECGs) with minimal associated clinical information. We sought to determine physicians' diagnostic agreement and accuracy when interpreting potential STEMI ECGs. METHODS AND RESULTS: A cross-sectional survey was performed consisting of 36 deidentified ECGs that had previously resulted in putative STEMI diagnoses. Emergency physicians, cardiologists, and interventional cardiologists participated in the survey. For each ECG, physicians were asked, "based on the ECG above, is there a blocked coronary artery present causing a STEMI?" The reference standard for ascertaining the STEMI diagnosis was subsequent emergent coronary arteriography. Responses were analyzed with generalized estimating equations to account for nested and repeated measures. One hundred twenty-four physicians interpreted a total of 4392 ECGs. Among all physicians, interreader agreement (kappa) for ECG interpretation was 0.33, reflecting poor agreement. The sensitivity to identify "true" STEMIs was 65% (95% CI: 63 to 67) and the specificity was 79% (95% CI: 77 to 81). There was a 6% increase in the odds of accurate ECG interpretation for every 5 years of experience since medical school graduation (OR 1.06, 95% CI: 1.02 to 1.10, P = 0.01). After adjusting for experience, there was no significant difference in the odds of accurate interpretation by specialty-Emergency Medicine (reference), General Cardiology (AOR 0.97, 95% CI: 0.79 to 1.2, P = 0.80), or Interventional Cardiology physicians (AOR 1.24, 95% CI: 0.93 to 1.7, P = 0.15). CONCLUSIONS: There is significant physician disagreement in interpreting ECGs with features concerning for STEMI. Such ECGs lack the necessary sensitivity and specificity to act as a suitable "stand-alone" diagnostic test.

Copeptin helps in the early detection of patients with acute myocardial infarction: primary results of the CHOPIN trial (Copeptin Helps in the early detection Of Patients with acute myocardial INfarction).

OBJECTIVES: The goal of this study was to demonstrate that copeptin levels <14 pmol/L allow ruling out acute myocardial infarction (AMI) when used in combination with cardiac troponin I (cTnI) <99 th percentile and a nondiagnostic electrocardiogram at the time of presentation to the emergency department (ED). BACKGROUND: Copeptin is secreted from the pituitary early in the course of AMI. METHODS: This was a 16-site study in 1,967 patients with chest pain presenting to an ED within 6 hours of pain onset. Baseline demographic characteristics and clinical data were collected prospectively. Copeptin levels and a contemporary sensitive cTnI (99 th percentile 40 ng/l; 10% coefficient of variation 0.03 µg/l) were measured in a core laboratory. Patients were followed up for 180 days. The primary outcome was diagnosis of AMI. Final diagnoses were adjudicated by 2 independent cardiologists blinded to copeptin results. RESULTS: AMI was the final diagnosis in 156 patients (7.9%). A negative copeptin and cTnI at baseline ruled out AMI for 58% of patients, with a negative predictive value of 99.2% (95% confidence interval: 98.5 to 99.6). AMIs not detected by the initial cTnI alone were picked up with copeptin >14 pmol/l in 23 (72%) of 32 patients. Non-ST-segment elevation myocardial infarctions undetected by cTnI at 0 h were detected with copeptin >14 pmol/l in 10 (53%) of 19 patients. Projected average time-to-decision could be reduced by 43% (from 3.0 h to 1.8 h) by the early rule out of 58% of patients. Both abnormal copeptin and cTnI were predictors of death at 180 days (p < 0.0001 for both; c index 0.784 and 0.800, respectively). Both were independent of age and each other and provided additional predictive value (all p < 0.0001). CONCLUSIONS: Adding copeptin to cTnI allowed safe rule out of AMI with a negative predictive value >99% in patients presenting with suspected acute coronary syndromes. This combination has the potential to rule out AMI in 58% of patients without serial blood draws.

Benefit or burden? A sociotechnical analysis of diagnostic computer kiosks in four California hospital emergency departments.

High expectations for new technologies coexist with wide variability in the actual adoption and impact of information technology (IT) projects in clinical settings, and the frequent failure to incorporate otherwise "successful" projects into routine practice. This paper draws on actor-network theory to present an in-depth, sociotechnical analysis of one such project--a computer kiosk designed to diagnose and expedite treatment of urinary tract infections (UTI) in adult women. Research at a hospital urgent care clinic demonstrated the kiosk program's effectiveness at diagnosing UTI and reducing patient wait times, and the kiosk was subsequently adopted by the clinic for routine patient care. However, a study promoting the adoption of the device at emergency departments (ED) was characterized by persistent staff resistance and lower-than-expected patient eligibility for kiosk-assisted care. The device was ultimately abandoned at all but one of the new sites. Observations and interviews with ED staff and the design/research team were conducted at four California EDs between April and July 2011 and point to conflicting understandings of evidence for the device's usefulness and reasons for its (non)adoption. The kiosk program's designers had attempted to "rationalize" medical work by embedding a formal representation of triage practices in the kiosk's software. However, the kiosk's "network" failed to stabilize as it encountered different patient populations, institutional politics, and the complex, pragmatic aspects of ED work at each site. The results of this evaluation challenge the persistent myth that a priori qualities and meanings inhere in technology regardless of context. The design and deployment of new IT projects in complex medical settings would benefit from empirically informed understandings of, and responses to, the contingent properties of human-technology relations.

Electrocardiographic criteria for ST-elevation myocardial infarction in patients with left ventricular hypertrophy.

Patients with electrocardiographic (ECG) left ventricular hypertrophy (LVH) have repolarization abnormalities of the ST segment that may be confused with an ischemic current of injury. We analyzed the ACTIVATE-SF database, a registry of consecutive emergency department ST-segment elevation (STE) myocardial infarction diagnoses from 2 medical centers. Univariate analysis was performed to identify ECG variables associated with presence of an angiographic culprit lesion. Recursive partitioning was then applied to identify a clinical decision-making rule that maximizes sensitivity and specificity for presence of an angiographic culprit lesion. Seventy-nine patients with ECG LVH underwent emergency cardiac catheterization for primary angioplasty. Patients with a culprit lesion had greater magnitude of STE (3.0 ± 1.8 vs 1.9 ± 1.0 mm, p = 0.005), more leads with STE (3.1 ± 1.6 vs 2.0 ± 1.8 leads, p = 0.002), and a greater ratio of STE to R-S-wave magnitude (median 25% vs 9.2%, p = 0.003). Univariate application of ECG criteria had limited sensitivity and a high false-positive rate for identifying patients with an angiographic culprit lesion. In patients with anterior territory STE, using a ratio of ST segment to R-S-wave magnitude ≥25% as a diagnostic criteria for STE myocardial infarction significantly improved specificity for an angiographic culprit lesion without decreasing sensitivity (c-statistic 0.82), with a net reclassification improvement of 37%. In conclusion, application of an ST segment to R-S-wave magnitude ≥25% rule may augment current criteria for determining which patients with ECG LVH should undergo primary angioplasty.

Delaying primary percutaneous coronary intervention for computed tomographic scans in the emergency department.

Patients presenting with suspected ST-segment elevation myocardial infarction (STEMI) may have important alternative diagnoses (e.g., aortic dissection, pulmonary emboli) or safety concerns for STEMI management (e.g., head trauma). Computed tomographic (CT) scanning may help in identifying these alternative diagnoses but may also needlessly delay primary percutaneous coronary intervention (PCI). We analyzed the ACTIVATE-SF Registry, which consists of consecutive patients with a clinical diagnosis of STEMI admitted to the emergency departments of 2 urban hospitals. Of 410 patients with a suspected diagnosis of STEMI, 45 (11%) underwent CT scanning before primary PCI. Presenting electrocardiograms, baseline risk factors, and presence of an angiographic culprit vessel were similar in those with and without CT scanning before PCI. Only 2 (4%) of these CT scans changed clinical management by identifying a stroke. Patients who underwent CT scanning had far longer door-to-balloon times (median 166 vs 75 minutes, p <0.001) and higher in-hospital mortality (20% vs 7.8%, p = 0.006). After multivariate adjustment, CT scanning in the emergency department before primary PCI remained independently associated with longer door-to-balloon times (100% longer, 95% confidence interval 60 to 160, p <0.001) but was no longer associated with mortality (odds ratio 1.4, p = 0.5). In conclusion, CT scanning before primary PCI rarely changed management and was associated with significant delays in door-to-balloon times. More judicious use of CT scanning should be considered.

Predictors of depressed left ventricular function in patients presenting with ST-elevation myocardial infarction.

Early in the course of ST-segment elevation myocardial infarction (STEMI), therapies that may harm patients who develop left ventricular (LV) dysfunction, such as ß-blockers, are often administered. The investigators analyzed the ACTIVATE-SF database, a registry of consecutive STEMI activations presenting to 2 medical centers at the University of California, San Francisco. LV dysfunction was defined as an ejection fraction ≤40% on echocardiography. Of 211 patients included in the analysis, 66 (31%) had LV ejection fractions ≤40%. Patients with LV dysfunction were older (63 ± 15 vs 56 ± 13 years, p = 0.002). In multivariate regression models, decreased renal function (reference group, creatinine <1.0 mg/dl; adjusted odds ratio [AOR] creatinine >1.5 mg/dl 6.35, 95% confidence interval [CI] 1.66 to 24.31, p = 0.007), a history of coronary artery disease (AOR 3.12, 95% CI 1.26 to 7.71, p = 0.014), ST-segment elevation >2 mm on 12-lead electrocardiography (AOR 2.78, 95% CI 1.31 to 5.87, p = 0.008), and need for mechanical ventilation (AOR 3.98, 95% CI 1.41 to 11.19, p = 0.009) increased the odds of LV dysfunction. Inferior ST-segment elevations were associated with 88% decreased odds of LV dysfunction (AOR 0.12, 95% CI 0.06 to 0.35, p <0.001). A prediction score using these characteristics stratified patients into low-, intermediate-, and high-risk groups for LV dysfunction; positive likelihood ratios for LV dysfunction in these groups were 0.07, 1.14, and 4.93, respectively. In conclusion, 5 key predictors of in-hospital LV dysfunction after STEMI were identified; a risk score based on these predictors helps to quickly identify patients presenting with STEMI who are at the highest risk for developing significant LV dysfunction and could guide optimal therapeutic choices.

Impact of door-to-activation time on door-to-balloon time in primary percutaneous coronary intervention for ST-segment elevation myocardial infarctions: a report from the Activate-SF registry.

BACKGROUND: Little is known about the components of door-to-balloon time among patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. We assessed the role of time from hospital arrival to ST-segment elevation myocardial infarction diagnosis (door-to-activation time) on door-to-balloon time in contemporary practice and evaluated factors that influence door-to-activation times. METHODS AND RESULTS: Registry data on 347 consecutive patients diagnosed with a ST-segment elevation myocardial infarction in the emergency department over 30 months at 2 urban primary percutaneous coronary intervention centers were analyzed. The primary study end point was the time from hospital arrival to catheterization laboratory activation by the emergency department physician, and we assessed factors associated with this period. Door-to-balloon time and its other components were secondary study end points. The median door-to-activation time was 19 minutes (interquartile range, 9-54). Variation in door-to-activation times explained 93% of the variation in door-to-balloon times and demonstrated the strongest correlation with door-to-balloon times (r=0.97). Achieving a door-to-activation time of ≤20 minutes resulted in an 89% chance of achieving a door-to-balloon time of ≤90 minutes compared with only 28% for patients with a door-to-activation time >20 minutes. Factors significantly associated with door-to-activation time include the following: prehospital ECG use (61% shorter, 95% confidence interval, -50 to -72%; P<0.001) and computed tomography scan use in the emergency department (245% longer, 95% confidence interval, +50 to +399%; P=0.001). CONCLUSIONS: The interval from hospital arrival to ST-segment elevation myocardial infarction diagnosis and catheterization laboratory activation (door-to-activation time) is a strong driver of overall door-to-balloon times. Achieving a door-to-activation time ≤20 minutes was key to achieving a door-to-balloon time ≤90 minutes. Delays in door-to-activation time are not associated with delays in other aspects of the primary percutaneous coronary intervention process.

Prevalence and factors associated with false-positive ST-segment elevation myocardial infarction diagnoses at primary percutaneous coronary intervention­capable centers: a report from the Activate-SF registry.

BACKGROUND: Rapid activation of the cardiac catheterization laboratory for primary percutaneous coronary intervention (PCI) improves outcomes for ST-segment elevation myocardial infarction (STEMI), but selected emphasis on minimizing time to reperfusion may lead to a greater frequency of false-positive activations. METHODS: We analyzed consecutive patients referred for primary PCI for a possible STEMI at 2 centers from October 2008 to April 2011. "False-positive STEMI activation" was defined as lack of a culprit lesion by angiography or by assessment of clinical, electrocardiographic, and biomarker data in the absence of angiography. Clinical and electrocardiographic factors associated with false-positive activations were evaluated in a backward stepwise selection bootstrapped logistic regression model. RESULTS: Of 411 STEMI activations by emergency physicians, 146 (36%) were deemed to be false-positive activations. Structural heart disease and heart failure were the most common diagnoses among false-positive activations. Electrocardiographic left ventricular hypertrophy (adjusted odds ratio [AOR], 3.15; 95% CI, 1.55-6.40; P=.001), a history of coronary disease (AOR, 1.93; 95% CI, 1.04-3.59; P=.04), or prior illicit drug abuse (AOR, 2.67; 95% CI, 1.13-6.26; P=.02) independently increased the odds of false-positive STEMI activations. Increasing body mass index decreased the odds of a false-positive activation (AOR, 0.91; 95% CI, 0.86-0.97; P=.004), as did angina at presentation (AOR, 0.28; 95% CI, 0.14-0.57; P < .001). CONCLUSIONS: More than a third of patients referred for primary PCI from the emergency department did not have a STEMI. Multiple patient-level characteristics were significantly associated with an increased odds of false-positive STEMI activation.