Higher intensity of 72-h noninvasive cardiac test referral does not improve short-term outcomes among emergency department patients with chest pain.

BACKGROUND: It is unclear whether referral for cardiac noninvasive testing (NIT) following emergency department (ED) chest pain encounters improves short-term outcomes. METHODS: This was a retrospective cohort study of patients presenting with chest pain, without ST-elevation myocardial infarction or myocardial injury by serum troponin testing, between 2013 and 2019 to 21 EDs within an integrated health care system. We examined the association between NIT referral (within 72 h of the ED encounter) and a primary outcome of 60-day major adverse cardiac events (MACE). Secondary outcomes were 60-day MACE without coronary revascularization (MACE-CR) and 60-day all-cause mortality. To account for confounding by indication for NIT, we grouped patient encounters into ranked tertiles of NIT referral intensity based on the likelihood of 72-h NIT referral associated with the initially assigned emergency physician, relative to local peers and within discrete time periods. Associations between NIT referral-intensity tertile and outcomes were assessed using risk-adjusted multivariable logistic regression. RESULTS: Among 210,948 eligible patient encounters, 72-h NIT referral frequency was 11.9%, 18.3%, and 25.9% in low, intermediate, and high NIT referral-intensity encounters, respectively. Compared with the low referral-intensity tertile, there was a higher risk of 60-day MACE within the high referral-intensity tertile (odds ratio [OR] = 1.11, 95% confidence interval [CI] = 1.04 to 1.17) due to more coronary revascularizations without corresponding differences in MACE-CR or all-cause mortality. In analyses stratified by patients' estimated risk (HEART score; 50.5% lower risk, 38.7% moderate risk, 10.8% higher risk), the difference in 60-day MACE was primarily attributable to moderate-risk encounters (OR = 1.15, 95% CI = 1.08 to 1.24), with no differences among either lower- (OR = 1.10, 95% CI = 0.92 to 1.31) or higher- (OR = 1.01, 95% CI = 0.90 to 1.14) risk encounters. CONCLUSION: Higher referral intensity for 72-h NIT was associated with higher risk of coronary revascularization but no difference in adverse events within 60 days. These findings further call into question the urgency of NIT among ED patients without objective evidence of myocardial injury.

Graded Coronary Risk Stratification for Emergency Department Patients With Chest Pain: A Controlled Cohort Study.

Background Resource utilization among emergency department (ED) patients with possible coronary chest pain is highly variable. Methods and Results Controlled cohort study amongst 21 EDs of an integrated healthcare system examining the implementation of a graded coronary risk stratification algorithm (RISTRA-ACS [risk stratification for acute coronary syndrome]). Thirteen EDs had access to RISTRA-ACS within the electronic health record (RISTRA sites) beginning in month 24 of a 48-month study period (January 2016 to December 2019); the remaining 8 EDs served as contemporaneous controls. Study participants had a chief complaint of chest pain and serum troponin measurement in the ED. The primary outcome was index visit resource utilization (observation unit or hospital admission, or 7-day objective cardiac testing). Secondary outcomes were 30-day objective cardiac testing, 60-day major adverse cardiac events (MACE), and 60-day MACE-CR (MACE excluding coronary revascularization). Difference-in-differences analyses controlled for secular trends with stratification by estimated risk and adjustment for risk factors, ED physician and facility. A total of 154 914 encounters were included. Relative to control sites, 30-day objective cardiac testing decreased at RISTRA sites among patients with low (≤2%) estimated 60-day MACE risk (-2.5%, 95% CI -3.7 to -1.2%, P<0.001) and increased among patients with non-low (>2%) estimated risk (+2.8%, 95% CI +0.6 to +4.9%, P=0.014), without significant overall change (-1.0%, 95% CI -2.1 to 0.1%, P=0.079). There were no statistically significant differences in index visit resource utilization, 60-day MACE or 60-day MACE-CR. Conclusions Implementation of RISTRA-ACS was associated with better allocation of 30-day objective cardiac testing and no change in index visit resource utilization or 60-day MACE. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03286179.

Prospective Validation and Comparative Analysis of Coronary Risk Stratification Strategies Among Emergency Department Patients With Chest Pain.

Background Coronary risk stratification is recommended for emergency department patients with chest pain. Many protocols are designed as "rule-out" binary classification strategies, while others use graded-risk stratification. The comparative performance of competing approaches at varying levels of risk tolerance has not been widely reported. Methods and Results This is a prospective cohort study of adult patients with chest pain presenting between January 2018 and December 2019 to 13 medical center emergency departments within an integrated healthcare delivery system. Using an electronic clinical decision support interface, we externally validated and assessed the net benefit (at varying risk thresholds) of several coronary risk scores (History, ECG, Age, Risk Factors, and Troponin [HEART] score, HEART pathway, Emergency Department Assessment of Chest Pain Score Accelerated Diagnostic Protocol), troponin-only strategies (fourth-generation assay), unstructured physician gestalt, and a novel risk algorithm (RISTRA-ACS). The primary outcome was 60-day major adverse cardiac event defined as myocardial infarction, cardiac arrest, cardiogenic shock, coronary revascularization, or all-cause mortality. There were 13 192 patient encounters included with a 60-day major adverse cardiac event incidence of 3.7%. RISTRA-ACS and HEART pathway had the lowest negative likelihood ratios (0.06, 95% CI, 0.03-0.10 and 0.07, 95% CI, 0.04-0.11, respectively) and the greatest net benefit across a range of low-risk thresholds. RISTRA-ACS demonstrated the highest discrimination for 60-day major adverse cardiac event (area under the receiver operating characteristic curve 0.92, 95% CI, 0.91-0.94, P<0.0001). Conclusions RISTRA-ACS and HEART pathway were the optimal rule-out approaches, while RISTRA-ACS was the best-performing graded-risk approach. RISTRA-ACS offers promise as a versatile single approach to emergency department coronary risk stratification. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT03286179.

Automated Retrospective Calculation of the EDACS and HEART Scores in a Multicenter Prospective Cohort of Emergency Department Chest Pain Patients.

OBJECTIVES: Coronary risk scores are commonly applied to emergency department patients with undifferentiated chest pain. Two prominent risk score-based protocols are the Emergency Department Assessment of Chest pain Score Accelerated Diagnostic Protocol (EDACS-ADP) and the History, ECG, Age, Risk factors, and Troponin (HEART) pathway. Since prospective documentation of these risk determinations can be challenging to obtain, quality improvement projects could benefit from automated retrospective risk score classification methodologies. METHODS: EDACS-ADP and HEART pathway data elements were prospectively collected using a Web-based electronic clinical decision support (eCDS) tool over a 24-month period (2018-2019) among patients presenting with chest pain to 13 EDs within an integrated health system. Data elements were also extracted and processed electronically (retrospectively) from the electronic health record (EHR) for the same patients. The primary outcome was agreement between the prospective/eCDS and retrospective/EHR data sets on dichotomous risk protocol classification, as assessed by kappa statistics (ĸ). RESULTS: There were 12,110 eligible eCDS uses during the study period, of which 66 and 47% were low-risk encounters by EDACS-ADP and HEART pathway, respectively. Agreement on low-risk status was acceptable for EDACS-ADP (ĸ = 0.73, 95% confidence interval [CI] = 0.72 to 0.75) and HEART pathway (ĸ = 0.69, 95% CI = 0.68 to 0.70) and for the continuous scores (interclass correlation coefficients = 0.87 and 0.84 for EDACS and HEART, respectively). CONCLUSIONS: Automated retrospective determination of low risk status by either the EDACS-ADP or the HEART pathway provides acceptable agreement compared to prospective score calculations, providing a feasible risk adjustment option for use in large data set analyses.

Increasing Safe Outpatient Management of Emergency Department Patients With Pulmonary Embolism: A Controlled Pragmatic Trial.

Background: Many low-risk patients with acute pulmonary embolism (PE) in the emergency department (ED) are eligible for outpatient care but are hospitalized nonetheless. One impediment to home discharge is the difficulty of identifying which patients can safely forgo hospitalization. Objective: To evaluate the effect of an integrated electronic clinical decision support system (CDSS) to facilitate risk stratification and decision making at the site of care for patients with acute PE. Design: Controlled pragmatic trial. (ClinicalTrials.gov: NCT03601676). Setting: All 21 community EDs of an integrated health care delivery system (Kaiser Permanente Northern California). Patients: Adult ED patients with acute PE. Intervention: Ten intervention sites selected by convenience received a multidimensional technology and education intervention at month 9 of a 16-month study period (January 2014 to April 2015); the remaining 11 sites served as concurrent controls. Measurements: The primary outcome was discharge to home from either the ED or a short-term (<24-hour) outpatient observation unit based in the ED. Adverse outcomes included return visits for PE-related symptoms within 5 days and recurrent venous thromboembolism, major hemorrhage, and all-cause mortality within 30 days. A difference-in-differences approach was used to compare pre-post changes at intervention versus control sites, with adjustment for demographic and clinical characteristics. Results: Among 881 eligible patients diagnosed with PE at intervention sites and 822 at control sites, adjusted home discharge increased at intervention sites (17.4% pre- to 28.0% postintervention) without a concurrent increase at control sites (15.1% pre- and 14.5% postintervention). The difference-in-differences comparison was 11.3 percentage points (95% CI, 3.0 to 19.5 percentage points; P = 0.007). No increases were seen in 5-day return visits related to PE or in 30-day major adverse outcomes associated with CDSS implementation. Limitation: Lack of random allocation. Conclusion: Implementation and structured promotion of a CDSS to aid physicians in site-of-care decision making for ED patients with acute PE safely increased outpatient management. Primary Funding Source: Garfield Memorial National Research Fund and The Permanente Medical Group Delivery Science and Physician Researcher Programs.

Performance of Coronary Risk Scores Among Patients With Chest Pain in the Emergency Department.

BACKGROUND: Both the modified History, Electrocardiogram, Age, Risk factors and Troponin (HEART) score and the Emergency Department Assessment of Chest pain Score (EDACS) can identify patients with possible acute coronary syndrome (ACS) at low risk (<1%) for major adverse cardiac events (MACE). OBJECTIVES: The authors sought to assess the comparative accuracy of the EDACS (original and simplified) and modified HEART risk scores when using cardiac troponin I (cTnI) cutoffs below the 99th percentile, and obtain precise MACE risk estimates. METHODS: The authors conducted a retrospective study of adult emergency department (ED) patients evaluated for possible ACS in an integrated health care system between 2013 and 2015. Negative predictive values for MACE (composite of myocardial infarction, cardiogenic shock, cardiac arrest, and all-cause mortality) were determined at 60 days. Reclassification analyses were used to assess the comparative accuracy of risk scores and lower cTnI cutoffs. RESULTS: A total of 118,822 patients with possible ACS were included. The 3 risk scores' accuracies were optimized using the lower limit of cTnI quantitation (<0.02 ng/ml) to define low risk for 60-day MACE, with reclassification yields ranging between 3.4% and 3.9%, while maintaining similar negative predictive values (range 99.49% to 99.55%; p = 0.27). The original EDACS identified the largest proportion of patients as low risk (60.6%; p < 0.0001). CONCLUSIONS: Among ED patients with possible ACS, the modified HEART score, original EDACS, and simplified EDACS all predicted a low risk of 60-day MACE with improved accuracy using a cTnI cutoff below the 99th percentile. The original EDACS identified the most low-risk patients, and thus may be the preferred risk score.

Outcomes Following Possible Undiagnosed Aneurysmal Subarachnoid Hemorrhage: A Contemporary Analysis.

OBJECTIVES: Existing literature suggests that patients with aneurysmal subarachnoid hemorrhage (aSAH) and "sentinel" aSAH symptoms prompting healthcare evaluations prior to aSAH diagnosis are at increased risk of unfavorable neurologic outcomes and death. Accordingly, these encounters have been presumed to be unrecognized opportunities to diagnose aSAH and the worse outcomes representative of the added risks of delayed diagnoses. We sought to reinvestigate this paradigm among a contemporary cohort of patients with aSAH. METHODS: A case-control cohort was retrospectively assembled among patients diagnosed with aSAH between January 1, 2007 and June 30, 2013 within an integrated healthcare delivery system. Patients with a discrete clinical evaluation for headache or neck pain within 14 days prior to formal aSAH diagnosis were identified as cases, and the remaining patients served as controls. Modified Rankin Scale scores at 90 days and 1 year were determined by structured chart review. Multivariable logistic regression controlling for age, sex, ethnicity, presence of intracerebral or intraventricular hemorrhage at diagnosis, and aneurysm size was used to compare adjusted outcomes. Sensitivity analyses were performed using varying definitions of favorable neurologic outcomes, a restricted control subgroup of patients with normal mental status at hospital admission, inclusion of additional cases that were diagnosed outside of the integrated health system, and exclusion of patients without evidence of subarachnoid blood on initial noncontrast cranial computed tomography (CT) at the diagnostic encounter (i.e. "CT-negative" SAH). RESULTS: A total of 450 patients with aSAH were identified, 46 (10%) of whom had clinical evaluations for possible aSAH-related symptoms in the 14 days preceding formal diagnosis (cases). In contrast to prior reports, no differences were observed among cases compared to control patients in adjusted odds of death or unfavorable neurologic status at 90 days (0.35, 95% confidence interval [CI] = 0.11-1.15; 0.59, 95% CI = 0.22-1.60, respectively) or at 1 year (0.58, 95% CI = 0.19-1.73; 0.52, 95% CI = 0.18-1.51, respectively). Likewise, neither restricting the analysis to a control subgroup of patients with normal mental status at hospital admission, varying the dichotomous definition of unfavorable neurologic outcome, inclusion of cases diagnosed outside the integrated health system, or exclusion of patients with CT-negative SAH resulted in significant adjusted outcome differences. CONCLUSION: In a contemporary cohort of patients with aSAH, we observed no statistically significant increase in the adjusted odds of death or unfavorable neurologic outcomes among patients with clinical evaluations for possible aSAH-related symptoms in the 14 days preceding formal diagnosis of aSAH. While these findings cannot exclude a smaller risk difference than previously reported, they can help refine decision analyses and testing threshold determinations for patients with possible aSAH.

False-negative Interpretations of Cranial Computed Tomography in Aneurysmal Subarachnoid Hemorrhage.

OBJECTIVES: Prior studies examining the sensitivity of cranial computed tomography (CT) for the detection of subarachnoid hemorrhage (SAH) have used the final radiology report as the reference standard. However, optimal sensitivity may have been underestimated due to misinterpretation of reportedly normal cranial CTs. This study aims to estimate the incidence of missed CT evidence of SAH among a cohort of patients with aneurysmal SAH (aSAH). METHODS: We performed a retrospective chart review of emergency department (ED) encounters within an integrated health delivery system between January 2007 and June 2013 to identify patients diagnosed with aSAH. All initial noncontrast CTs from aSAH cases diagnosed by lumbar puncture (LP) and angiography following a reportedly normal noncontrast cranial CT (CT-negative aSAH) were then reviewed in a blinded, independent fashion by two board-certified neuroradiologists to assess for missed evidence of SAH. Reviewers rated the CT studies as having definite evidence of SAH, probable evidence of SAH, or no evidence of SAH. Control patients who underwent a negative evaluation for aSAH based on cranial CT and LP results were also included at random in the imaging review cohort. RESULTS: A total of 452 cases of aSAH were identified; 18 (4%) were cases of CT-negative aSAH. Of these, seven (39%) underwent cranial CT within 6 hours of headache onset, and two (11%) had their initial CTs formally interpreted by board-certified neuroradiologists. Blinded independent CT review revealed concordant agreement for either definite or probable evidence of SAH in nine of 18 (50%) cases overall and in five of the seven (71%) CTs performed within 6 hours of headache onset. Inter-rater agreement was 83% for definite SAH and 72% for either probable or definite SAH. CONCLUSIONS: CT evidence of SAH was frequently present but unrecognized according to the final radiology report in cases of presumed CT-negative aSAH. This finding may help explain some of the discordance between prior studies examining the sensitivity of cranial CT for SAH.

Sensitivity of a Clinical Decision Rule and Early Computed Tomography in Aneurysmal Subarachnoid Hemorrhage.

INTRODUCTION: Application of a clinical decision rule for subarachnoid hemorrhage, in combination with cranial computed tomography (CT) performed within six hours of ictus (early cranial CT), may be able to reasonably exclude a diagnosis of aneurysmal subarachnoid hemorrhage (aSAH). This study's objective was to examine the sensitivity of both early cranial CT and a previously validated clinical decision rule among emergency department (ED) patients with aSAH and a normal mental status. METHODS: Patients were evaluated in the 21 EDs of an integrated health delivery system between January 2007 and June 2013. We identified by chart review a retrospective cohort of patients diagnosed with aSAH in the setting of a normal mental status and performance of early cranial CT. Variables comprising the SAH clinical decision rule (age≥40, presence of neck pain or stiffness, headache onset with exertion, loss of consciousness at headache onset) were abstracted from the chart and assessed for inter-rater reliability. RESULTS: One hundred fifty-five patients with aSAH met study inclusion criteria. The sensitivity of early cranial CT was 95.5% (95% CI [90.9-98.2]). The sensitivity of the SAH clinical decision rule was also 95.5% (95% CI [90.9-98.2]). Since all false negative cases for each diagnostic modality were mutually independent, the combined use of both early cranial CT and the clinical decision rule improved sensitivity to 100% (95% CI [97.6-100.0]). CONCLUSION: Neither early cranial CT nor the SAH clinical decision rule demonstrated ideal sensitivity for aSAH in this retrospective cohort. However, the combination of both strategies might optimize sensitivity for this life-threatening disease.

Emergency Physician Attitudes, Preferences, and Risk Tolerance for Stroke as a Potential Cause of Dizziness Symptoms.

INTRODUCTION: We evaluated emergency physicians' (EP) current perceptions, practice, and attitudes towards evaluating stroke as a cause of dizziness among emergency department patients. METHODS: We administered a survey to all EPs in a large integrated healthcare delivery system. The survey included clinical vignettes, perceived utility of historical and exam elements, attitudes about the value of and requisite post-test probability of a clinical prediction rule for dizziness. We calculated descriptive statistics and post-test probabilities for such a clinical prediction rule. RESULTS: The response rate was 68% (366/535). Respondents' median practice tenure was eight years (37% female, 92% emergency medicine board certified). Symptom quality and typical vascular risk factors increased suspicion for stroke as a cause of dizziness. Most respondents reported obtaining head computed tomography (CT) (74%). Nearly all respondents used and felt confident using cranial nerve and limb strength testing. A substantial minority of EPs used the Epley maneuver (49%) and HINTS (head-thrust test, gaze-evoked nystagmus, and skew deviation) testing (30%); however, few EPs reported confidence in these tests' bedside application (35% and 16%, respectively). Respondents favorably viewed applying a properly validated clinical prediction rule for assessment of immediate and 30-day stroke risk, but indicated it would have to reduce stroke risk to <0.5% to be clinically useful. CONCLUSION: EPs report relying on symptom quality, vascular risk factors, simple physical exam elements, and head CT to diagnose stroke as the cause of dizziness, but would find a validated clinical prediction rule for dizziness helpful. A clinical prediction rule would have to achieve a 0.5% post-test stroke probability for acceptability.

Implementation of Computerized Physician Order Entry Is Associated With Increased Thrombolytic Administration for Emergency Department Patients With Acute Ischemic Stroke.

STUDY OBJECTIVE: Electronic health record systems with computerized physician order entry and condition-specific order sets are intended to standardize patient management and minimize errors of omission. However, the effect of these systems on disease-specific process measures and patient outcomes is not well established. We seek to evaluate the effect of computerized physician order entry electronic health record implementation on process measures and short-term health outcomes for patients hospitalized with acute ischemic stroke. METHODS: We conducted a quasi-experimental cohort study of patients hospitalized for acute ischemic stroke with concurrent controls that took advantage of the staggered implementation of a comprehensive computerized physician order entry electronic health record across 16 medical centers within an integrated health care delivery system from 2007 to 2012. The study population included all patients admitted to the hospital from the emergency department (ED) for acute ischemic stroke, with an initial neuroimaging study within 2.5 hours of ED arrival. We evaluated the association between the availability of a computerized physician order entry electronic health record and the rates of ED intravenous tissue plasminogen activator administration, hospital-acquired pneumonia, and inhospital and 90-day mortality, using doubly robust estimation models to adjust for demographics, comorbidities, secular trends, and concurrent primary stroke center certification status at each center. RESULTS: Of 10,081 eligible patients, 6,686 (66.3%) were treated in centers after the computerized physician order entry electronic health record had been implemented. Computerized physician order entry was associated with significantly higher rates of intravenous tissue plasminogen activator administration (rate difference 3.4%; 95% confidence interval 0.8% to 6.0%) but not with significant rate differences in pneumonia or mortality. CONCLUSION: For patients hospitalized for acute ischemic stroke, computerized physician order entry use was associated with increased use of intravenous tissue plasminogen activator.

Validation of cerebrospinal fluid findings in aneurysmal subarachnoid hemorrhage.

BACKGROUND: Recently proposed cutoff criteria for cerebrospinal fluid (CSF) analyses might safely exclude a diagnosis of aneurysmal subarachnoid hemorrhage (aSAH). OBJECTIVE: The objective of this study was to examine the sensitivity of a CSF red blood cell (RBC) count greater than 2000 × 10(6)/L (ie, 2000 RBCs per microliter) or the presence of visible CSF xanthochromia in identifying patients with aSAH. METHODS: We identified a retrospective case series of patients diagnosed with aSAH after lumbar puncture (LP) in an integrated health delivery system between January 2000 and June 2013 by chart review. All identified patients had at least 1 cerebral aneurysm that was treated with a neurosurgical or endovascular intervention during the index hospitalization. The lowest CSF RBC count was used for validation analysis. Cerebrospinal fluid color was determined by visual inspection. Xanthochromia was defined as pink, orange, or yellow pigmentation of CSF supernatant. RESULTS: Sixty-four patients met study inclusion criteria. Of these, 17 (33%) of 52 underwent LP within 12 hours of headache onset, and 49 (84%) of 58 exhibited CSF xanthochromia. The median CSF RBC count was 63250 × 10(6)/L. The sensitivity of a CSF RBC count of greater than 2000 × 10(6)/L in identifying aSAH was 96.9% (95% confidence interval, 89.3%-99.1%). Additional consideration of CSF xanthochromia resulted in a sensitivity of 100% (95% confidence interval, 94.3%-100%). CONCLUSIONS: All patients in this case series of patients with aSAH had either a CSF RBC count greater than 2000 × 10(6)/L or visible CSF xanthochromia, increasing the likelihood that this proposed cutoff strategy may safely identify patients who warrant further investigation for an aneurysmal cause of subarachnoid hemorrhage.