Automated interpretation of stress echocardiography reports using natural language processing.

Aims: Stress echocardiography (SE) findings and interpretations are commonly documented in free-text reports. Reusing SE results requires laborious manual reviews. This study aimed to develop and validate an automated method for abstracting SE reports in a large cohort. Methods and results: This study included adult patients who had SE within 30 days of their emergency department visit for suspected acute coronary syndrome in a large integrated healthcare system. An automated natural language processing (NLP) algorithm was developed to abstract SE reports and classify overall SE results into normal, non-diagnostic, infarction, and ischaemia categories. Randomly selected reports (n = 140) were double-blindly reviewed by cardiologists to perform criterion validity of the NLP algorithm. Construct validity was tested on the entire cohort using abstracted SE data and additional clinical variables. The NLP algorithm abstracted 6346 consecutive SE reports. Cardiologists had good agreements on the overall SE results on the 140 reports: Kappa (0.83) and intraclass correlation coefficient (0.89). The NLP algorithm achieved 98.6% specificity and negative predictive value, 95.7% sensitivity, positive predictive value, and F-score on the overall SE results and near-perfect scores on ischaemia findings. The 30-day acute myocardial infarction or death outcomes were highest among patients with ischaemia (5.0%), followed by infarction (1.4%), non-diagnostic (0.8%), and normal (0.3%) results. We found substantial variations in the format and quality of SE reports, even within the same institution. Conclusions: Natural language processing is an accurate and efficient method for abstracting unstructured SE reports. This approach creates new opportunities for research, public health measures, and care improvement.

Single vs Serial Measurements of Cardiac Troponin Level in the Evaluation of Patients in the Emergency Department With Suspected Acute Myocardial Infarction.

Importance: Chest pain is among the most common reasons for emergency department (ED) presentations. However, most patients are at low risk for acute coronary syndrome (ACS), with low cardiac adverse outcomes rates. Biomarker testing with troponin levels is key in the initial assessment for ACS. Although serial troponin testing can improve the diagnosis of ACS in clinical practice, some patients deemed to be low risk are discharged after a single negative troponin test result. Objective: To report the clinical outcomes of patients discharged after a single negative troponin test result compared with patients discharged after serial troponin measurements. Design, Setting, and Participants: This is a retrospective cohort study of ED encounters from May 5, 2016, to December 1, 2017, across 15 community EDs within an integrated health care system in southern California. The study cohort includes 27 918 adult ED encounters in which patients were evaluated for suspected ACS with a HEART (history, electrocardiogram, age, risk factors, and troponin) score and an initial conventional troponin-I measurement below the level of detection (<0.02 ng/mL). Statistical analysis was performed from December 1, 2019, to December 1, 2020. Exposure: Single troponin test vs multiple troponin tests. Main Outcomes and Measures: The primary outcome was acute myocardial infarction or cardiac mortality; secondary outcomes included coronary artery bypass graft, percutaneous coronary intervention, invasive coronary angiography, and unstable angina within 30 days of discharge. A multivariable logistic regression model was performed to evaluate the association between testing strategies and clinical outcomes. Results: A total of 27 918 patient encounters (16 212 women [58.1%]; mean [SD] age, 58.7 [15.2] years) were included in the study. Of patients with an initial troponin measurement below the level of detection, 14 459 (51.8%) were discharged after a single troponin measurement, and 13 459 (48.2%) underwent serial troponin tests. After adjustment for cardiac risk factors and comorbidities, there was no statistically significant difference in the primary outcome of acute myocardial infarction or cardiac mortality within 30 days between the 2 groups (single troponin, 56 [0.4%] vs serial troponin, 52 [0.4%]; adjusted odds ratio, 1.41 [95% CI, 0.96-2.07]). Patients discharged after a single troponin test had lower rates of coronary artery bypass graft (adjusted odds ratio, 0.24 [95% CI, 0.11-0.48]) and invasive coronary angiography (adjusted odds ratio, 0.46 [95% CI, 0.38-0.56]). Conclusions and Relevance: This study suggests that patients are routinely discharged from the ED after a single negative troponin test result, and when compared with serial troponin testing, a single troponin test appears safe based on current physician decision-making, with no difference in rates of 30-day cardiac mortality and acute myocardial infarction, which are low in both groups.

Higher Emergency Physician Chest Pain Hospitalization Rates Do Not Lead to Improved Patient Outcomes.

BACKGROUND: Wide variation exists for hospital admission rates for the evaluation of possible acute coronary syndrome, but there are limited data on physician-level variation. Our aim is to describe physicians' rates of admission for suspected acute coronary syndrome and associated 30-day major adverse events. METHODS: We conducted a retrospective analysis of adult emergency department chest pain encounters from January 2016 to December 2017 across 15 community emergency departments within an integrated health system in Southern California. The unit of analysis was the Emergency physician. The primary outcome was the proportion of patients admitted/observed in the hospital. Secondary analysis described the 30-day incidence of death or acute myocardial infarction. RESULTS: Thirty-eight thousand seven hundred seventy-eight patients encounters were included among 327 managing physicians. The median number of encounters per physician was 123 (interquartile range, 82-157) with an overall admission/observation rate of 14.0%. Wide variation in individual physician admission rates were observed (unadjusted, 1.5%-68.9%) and persisted after case-mix adjustments (adjusted, 5.5%-27.8%). More clinical experience was associated with a higher likelihood of hospital care. There was no difference in 30-day death or acute myocardial infarction between high- and low-admitting physician quartiles (unadjusted, 1.70% versus 0.82% and adjusted, 1.33% versus 1.29%). CONCLUSIONS: Wide variation persists in physician-level admission rates for emergency department chest pain evaluation, even in a well-integrated health system. There was no associated benefit in 30-day death or acute myocardial infarction for patients evaluated by high-admitting physicians. This suggests an additional opportunity to investigate the safe reduction of physician-level variation in the use of hospital care.

Early Noninvasive Cardiac Testing After Emergency Department Evaluation for Suspected Acute Coronary Syndrome.

Importance: Professional guidelines recommend noninvasive cardiac testing (NIT) within 72 hours of an emergency department (ED) evaluation for suspected acute coronary syndrome. However, there is inexact evidence that this strategy reduces the risk of future death or acute myocardial infarction (MI). Objective: To evaluate the effectiveness of early NIT in reducing the risk of death or acute MI within 30 days. Design, Setting, and Participants: This retrospective, multicenter cohort study within the Kaiser Permanente Southern California integrated health care delivery system compared the effectiveness of early noninvasive cardiac testing vs no testing in patients with chest pain and in whom acute MI was ruled out who presented to an ED from January 2015 to December 2017. Patients were followed up for up to 30 days after emergency department discharge. Exposures: Noninvasive cardiac testing performed within 3 days of an ED evaluation for suspected acute coronary syndrome. Main Outcomes and Measures: The primary outcome was composite risk of death or acute MI, within 30 days of an ED discharge. Results: A total of 79 040 patients were evaluated in this study, of whom 57.7% were female. The mean (SD) age of the cohort was 57 (16) years, and 16 164 patients (21%) had completed early NIT. The absolute risk of death or MI within 30 days was low (<1%). Early NIT had the minor benefit of reducing the absolute composite risk of death or MI (0.4% [95% CI, -0.6% to -0.3%]), and, separately, of death (0.2% [95% CI, -0.2% to -0.1%]), MI (-0.3% [95% CI, -0.5% to -0.1%]), and major adverse cardiac event (-0.5% [95% CI, -0.7% to -0.3%]). The number needed to treat was 250 to avoid 1 death or MI, 500 to avoid 1 death, 333 to avoid 1 MI, and 200 to avoid 1 major adverse cardiovascular event within 30 days. Subgroup analysis revealed a number needed to treat of 14 to avoid 1 death or MI in the subset of patients with elevated troponin. Conclusions and Relevance: Early NIT was associated with a small decrease in the risk of death or MI in patients admitted to the ED with suspected acute coronary syndrome, but this clinical strategy may not be optimal for most patients given the large number needed to treat.

Evaluation of Outpatient Cardiac Stress Testing After Emergency Department Encounters for Suspected Acute Coronary Syndrome.

STUDY OBJECTIVE: Professional guidelines recommend 72-hour cardiac stress testing after an emergency department (ED) evaluation for possible acute coronary syndrome. There are limited data on actual compliance rates and effect on patient outcomes. Our aim is to describe rates of completion of noninvasive cardiac stress testing and associated 30-day major adverse cardiac events. METHODS: We conducted a retrospective analysis of ED encounters from June 2015 to June 2017 across 13 community EDs within an integrated health system in Southern California. The study population included all adults with a chest pain diagnosis, troponin value, and discharge with an order for an outpatient cardiac stress test. The primary outcome was the proportion of patients who completed an outpatient stress test within the recommended 3 days, 4 to 30 days, or not at all. Secondary analysis described the 30-day incidence of major adverse cardiac events. RESULTS: During the study period, 24,459 patients presented with a chest pain evaluation requiring troponin analysis and stress test ordering from the ED. Of these, we studied the 7,988 patients who were discharged home to complete diagnostic testing, having been deemed appropriate by the treating clinicians for an outpatient stress test. The stress test completion rate was 31.3% within 3 days and 58.7% between 4 and 30 days, and 10.0% of patients did not complete the ordered test. The 30-day rates of major adverse cardiac events were low (death 0.0%, acute myocardial infarction 0.7%, and revascularization 0.3%). Rapid receipt of stress testing was not associated with improved 30-day major adverse cardiac events (odds ratio 0.92; 95% confidence interval 0.55 to 1.54). CONCLUSION: Less than one third of patients completed outpatient stress testing within the guideline-recommended 3 days after initial evaluation. More important, the low adverse event rates suggest that selective outpatient stress testing is safe. In this cohort of patients selected for outpatient cardiac stress testing in a well-integrated health system, there does not appear to be any associated benefit of stress testing within 3 days, nor within 30 days, compared with those who never received testing at all. The lack of benefit of obtaining timely testing, in combination with low rates of objective adverse events, may warrant reassessment of the current guidelines.

Effect of a HEART Care Pathway on Chest Pain Management Within an Integrated Health System.

STUDY OBJECTIVE: We describe the association of implementing a History, ECG, Age, Risk Factors, and Troponin (HEART) care pathway on use of hospital care and noninvasive stress testing, as well as 30-day patient outcomes in community emergency departments (EDs). METHODS: We performed a prospective interrupted-time-series study of adult encounters for patients evaluated for suspected acute coronary syndrome. The primary outcome was hospitalization or observation, noninvasive stress testing, or both within 30 days. The secondary outcome was 30-day all-cause mortality or acute myocardial infarction. A generalized estimating equation segmented logistic regression model was used to compare the odds of the primary outcome before and after HEART implementation. All models were adjusted for patient and facility characteristics and fit with physicians as a clustering variable. RESULTS: A total of 65,393 ED encounters (before, 30,522; after, 34,871) were included in the study. Overall, 33.5% (before, 35.5%; after, 31.8%) of ED chest pain encounters resulted in hospitalization or observation, noninvasive stress testing, or both. Primary adjusted results found a significant decrease in the primary outcome postimplementation (odds ratio 0.984; 95% confidence interval [CI] 0.974 to 0.995). This resulted in an absolute adjusted month-to-month decrease of 4.39% (95% CI 3.72% to 5.07%) after 12 months' follow-up, with a continued trend downward. There was no difference in 30-day mortality or myocardial infarction (0.6% [before] versus 0.6% [after]; odds ratio 1.02; 95% CI 0.97 to 1.08). CONCLUSION: Implementation of a HEART pathway in the ED evaluation of patients with chest pain resulted in less inpatient care and noninvasive cardiac testing and was safe. Using HEART to risk stratify chest pain patients can improve the efficiency and quality of care.

Emergency Department Crowding and Outcomes After Emergency Department Discharge.

STUDY OBJECTIVE: We assess whether a panel of emergency department (ED) crowding measures, including 2 reported by the Centers for Medicare & Medicaid Services (CMS), is associated with inpatient admission and death within 7 days of ED discharge. METHODS: We conducted a retrospective cohort study of ED discharges, using data from an integrated health system for 2008 to 2010. We assessed patient transit-level (n=3) and ED system-level (n=6) measures of crowding, using multivariable logistic regression models. The outcome measures were inpatient admission or death within 7 days of ED discharge. We defined a clinically important association by assessing the relative risk ratio and 95% confidence interval (CI) difference and also compared risks at the 99th percentile and median value of each measure. RESULTS: The study cohort contained a total of 625,096 visits to 12 EDs. There were 16,957 (2.7%) admissions and 328 (0.05%) deaths within 7 days. Only 2 measures, both of which were patient transit measures, were associated with the outcome. Compared with a median evaluation time of 2.2 hours, the evaluation time of 10.8 hours (99th percentile) was associated with a relative risk of 3.9 (95% CI 3.7 to 4.1) of an admission. Compared with a median ED length of stay (a CMS measure) of 2.8 hours, the 99th percentile ED length of stay of 11.6 hours was associated with a relative risk of 3.5 (95% CI 3.3 to 3.7) of admission. No system measure of ED crowding was associated with outcomes. CONCLUSION: Our findings suggest that ED length of stay is a proxy for unmeasured differences in case mix and challenge the validity of the CMS metric as a safety measure for discharged patients.

Qualitative factors in patients who die shortly after emergency department discharge.

OBJECTIVES: Early death after emergency department (ED) discharge may signal opportunities to improve care. Prior studies are limited by incomplete mortality ascertainment and lack of clinically important information in administrative data. The goal in this hypothesis-generating study was to identify patient and process of care themes that may provide possible explanations for early postdischarge mortality. METHODS: This was a qualitative analysis of medical records of adult patients who visited the ED of any of six hospitals in an integrated health system (Kaiser Permanente Southern California [KPSC]) and died within 7 days of discharge in 2007 and 2008. Nonmembers, visits to non-health plan hospitals, patients receiving or referred to hospice care, and patients with do not attempt resuscitation or do not intubate orders (DNAR/DNI) were excluded. Under the guidance of two qualitative research scientists, a team of three emergency physicians used grounded theory techniques to identify patient clinical presentations and processes of care that serve as potential explanations for poor outcome after discharge. RESULTS: The source population consisted of a total of 290,092 members with 446,120 discharges from six KPSC EDs in 2007 and 2008. A total of 203 deaths occurred within 7 days of ED discharge (0.05%). Sixty-one randomly chosen cases were reviewed. Patient-level themes that emerged included an unexplained persistent acute change in mental status, recent fall, abnormal vital signs, ill-appearing presentation, malfunctioning indwelling device, and presenting symptoms remaining at discharge. Process-of-care factors included a discrepancy in history of present illness, incomplete physical examination, and change of discharge plan by a third party, such as a consulting or admitting physician. CONCLUSIONS: In this hypothesis-generating study, qualitative research techniques were used to identify clinical and process-of-care factors in patients who died within days after discharge from an ED. These potential predictors will be formally tested in a future quantitative study.

Patterns and predictors of short-term death after emergency department discharge.

STUDY OBJECTIVE: The emergency department (ED) is an inherently high-risk setting. Early death after an ED evaluation is a rare and devastating outcome; understanding it can potentially help improve patient care and outcomes. Using administrative data from an integrated health system, we describe characteristics and predictors of patients who experienced 7-day death after ED discharge. METHODS: Administrative data from 12 hospitals were used to identify death after discharge in adults aged 18 year or older within 7 days of ED presentation from January 1, 2007, to December 31, 2008. Patients who were nonmembers of the health system, in hospice care, or treated at out-of-network EDs were excluded. Predictors of 7-day postdischarge death were identified with multivariable logistic regression. RESULTS: The study cohort contained a total of 475,829 members, with 728,312 discharges from Kaiser Permanente Southern California EDs in 2007 and 2008. Death within 7 days of discharge occurred in 357 cases (0.05%). Increasing age, male sex, and number of preexisting comorbidities were associated with increased risk of death. The top 3 primary discharge diagnoses predictive of 7-day death after discharge included noninfectious lung disease (odds ratio [OR] 7.1; 95% confidence interval [CI] 2.9 to 17.4), renal disease (OR 5.6; 95% CI 2.2 to 14.2), and ischemic heart disease (OR 3.8; 95% CI 1.0 to 13.6). CONCLUSION: Our study suggests that 50 in 100,000 patients in the United States die within 7 days of discharge from an ED. To our knowledge, our study is the first to identify potentially "high-risk" discharge diagnoses in patients who experience a short-term death after discharge.

Predictors of short-term (seven-day) cardiac outcomes after emergency department visit for syncope.

Syncope is a common reason for emergency department (ED) visits, and patients are often admitted to exclude syncope of cardiovascular origin. Population-based data on patterns and predictors of cardiac outcomes may improve decision-making. Our objective was to identify patterns and predictors of short-term cardiac outcomes in ED patients with syncope. Administrative data from an integrated health system of 11 Southern California EDs were used to identify cardiac outcomes after ED presentation for syncope from January 1, 2002, to December 31, 2005. Syncope and cause of death were identified by codes from the International Classification of Disease, Ninth Revision. Cardiac outcomes included cardiac death and hospitalization or procedure consistent with ischemic heart disease, valvular disease, or arrhythmia. Predictors of cardiac outcomes were identified through multivariate logistic regression. There were 35,330 adult subjects who accounted for 39,943 ED visits for syncope. Risk of cardiac outcome sharply decreased following the 7 days after syncope. A 7-day cardiac outcome occurred in 893 cases (3%). Positive predictors of 7-day cardiac outcomes included age > or =60 years, male gender, congestive heart failure, ischemic heart disease, cardiac arrhythmia, and valvular heart disease. Negative predictors included dementia, pacemaker, coronary revascularization, and cerebrovascular disease. There was an age-dependent relation between 7-day cardiac outcomes and arrhythmia and valvular disease, with younger patients (<60 years of age) having greater risk of an event compared to their same-age counterparts. In conclusion, ED decision-making should focus on risk of cardiac event in the first 7 days after syncope and special attention should be given to younger patients with cardiac co-morbidities.