Prevalence of Pulmonary Embolism in Patients With Syncope

Intermediate-Risk and High-Risk Pulmonary Embolism: Recognition and Management: Cardiology Clinics: Cardiac Emergencies

Pulmonary embolism (PE) is the third most common cause of cardiovascular death. Every specialty of medical practitioner will encounter PE in their patients, and should be prepared to employ contemporary strategies for diagnosis and initial risk-stratification. Treatment of PE is based on risk-stratification, with anticoagulation for all patients, and advanced modalities including systemic thrombolysis, catheter-directed therapies, and mechanical circulatory supports utilized in a manner paralleling PE severity and clinical context.

How to recognize pulmonary embolism in syncope patients: A simple rule

BACKGROUND

Syncope can be the presenting symptom of Pulmonary Embolism (PE). It is not known wether using a standardized algorithm to rule-out PE in all patients with syncope admitted to the Emergency Departments (ED) is of value or can lead to overdiagnosis and overtreatment.

METHODS

We tested if simple anamnestic and clinical parameters could be used as a rule to identify patients with syncope and PE in a multicenter observational study. The rule's sensitivity was tested on a cohort of patients that presented to the ED for syncopal episodes caused by PE. The clinical impact of the rule was assessed on a population of consecutive patients admitted for syncope in the ED.

RESULTS

Patients were considered rule-positive in the presence of any of the following: hypotension, tachycardia, peripheral oxygen saturation ≤ 93 % (SpO2), chest pain, dyspnea, recent history of prolonged bed rest, clinical signs of deep vein thrombosis, history of previous venous thrombo-embolism and active neoplastic disease. The sensitivity of the rule was 90.3 % (95 % CI: 74.3 % to 98.0 %). The application of the rule to a population of 217 patients with syncope would have led to a 70 % reduction in the number of subjects needing additional diagnostic tests to exclude PE.

CONCLUSIONS

Most patients with syncope due to PE present with anamnestic and clinical features indicative of PE diagnosis. A clinical decision rule can be used to identify patients who would benefit from further diagnostic tests to exclude PE, while reducing unnecessary exams that could lead to over-testing and over-diagnosis.

Emergency Ultrasound Unveils Intermediate-High Risk Saddle Pulmonary Embolism with Extensive Bilateral Clot Burden, Masquerading as Micturition Syncope: A Case Report

BACKGROUND

Isolated syncope as the manifestation of pulmonary embolism (PE) is a rare and diagnostically challenging presentation that often leads to delayed or missed diagnosis, increasing morbidity and mortality. In spite of emphasizing cardiovascular etiologies of syncope, current guidelines offer essentially no guidance in establishing a diagnostic workup for PE in these patients. By performing bedside echocardiography, emergency physicians can accurately identify concerning features suggestive of PE in patients with syncope.

CASE REPORT

A 78-year-old man, receiving ertapenem via a peripherally inserted central catheter for treatment of extended spectrum β-lactamase urinary tract infection, presented to the emergency department for isolated syncope with collapse while urinating. Arriving asymptomatic with normal vital signs and a benign physical examination, a presumptive diagnosis of micturition syncope was made. However, subtle vital sign changes on reassessment prompted performance of a point-of-care echocardiogram, which revealed signs of right heart strain. A computed tomography angiogram confirmed a saddle PE with extensive bilateral clot burden. Catheter-directed thrombectomy was performed via interventional radiology, with successful removal of pulmonary emboli. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Pulmonary embolism presenting as isolated syncope represents a daunting diagnostic dilemma, as emergency physicians may not consider it, or anchor on more benign etiologies of syncope. Although lacking sufficient sensitivity to rule out PE, point-of-care echocardiography to evaluate for signs of right heart strain can quickly and effectively point toward the diagnosis, while also assessing for other emergent cardiovascular causes of syncope. Given the lack of evidence-based guidance concerning PE presenting as syncope, bedside echocardiography should be highly considered as a part of the emergency physician's diagnostic workup, especially in patients with abnormal vital signs.

"Hospital survival of patients with pulmonary embolism in a country with limited resources case of the city of Kinshasa"

BACKGROUND

Pulmonary embolism is a frequent cause of intra-hospital mortality. The survival of patients depends not only on the speed of diagnosis but also on the treatment initiated.

OBJECTIVE

to evaluate the intra-hospital survival of patients with pulmonary embolism in the city of Kinshasa.

METHODOLOGY

analytical cross-sectional study based on non-probability convenience sampling carried out in the city of Kinshasa; three hospitals selected for convenience on the basis of their technical platforms. The patients were judged to have had a pulmonary embolism after a chest CT angiography proved it. The data recorded on the Kobocollect site were exported in Excel format and analyzed with SPSS software version 23. The comparison of the means was made using the Student test and that frequencies with the Yates Chi-square test. The association was attributed by the calculation of the odds ratio and the survival presented according to the Cox regression.

RESULTS

Eighty-nine cases or 63 women and 26 men were analyzed, the mean age was 64.4 ± 15.6 years. Individuals over 65 died more (ß=0.043 and p-Value of 0.01) the female sex multiplied by 1.38 the risk of death (DNS, p-Value = 0.478). Approximately 80% of patients were classified as PESI stage II or III. Starting Rivaroxaban from the outset does not show any difference with enoxaparin in terms of intra-hospital survival.

CONCLUSION

Pulmonary embolism is a real problem in our environment, the age of more than 65 years and the female sex are factors of poor prognosis and predicted survival.

The role of geographic disparities in outcomes after orthopaedic trauma surgery

INTRODUCTION

Healthcare disparities linked to patient rurality and socioeconomic status are known to exist, but few studies have examined the effect of urban versus rural status on outcomes after orthopedic trauma surgery. The aim of this study was to examine the correlation between patient rurality, socioeconomic status, and outcomes after orthopedic trauma.

MATERIALS AND METHODS

This is a retrospective cohort study of patients diagnosed with a hip or long bone fracture between January 2016 and December 2017. Data were collected from the Nationwide Inpatient Sample (NIS), a 20% weighted sample of 95% of the U.S. inpatient population. Patients were stratified into 3 groups: isolated hip fracture, isolated long bone fracture, and polytrauma. Bivariate analysis was completed using chi-squared tests for categorical variables and t-tests for continuous variables. Multivariable analysis was completed using population-weighted logistic regression models, based on a conceptual model derived selection of covariates.

RESULTS

We included 235,393 patients diagnosed with a hip or extremity fracture. These were weighted to represent 1,176,965 patients nationally. In the hip fracture group, rural patient status was associated with higher odds of mortality (OR 1.32, P < 0.001) but not complications (OR 0.95, P = 0.082). In the extremity fracture and polytrauma groups, rural patient status was not associated with significantly higher odds of mortality or complications. In the urban polytrauma group, zip code with below-median income was associated with increased odds of mortality (OR 1.23, P = 0.002) but not complications. In the rural polytrauma group, zip code with below-median income was not associated with significantly increased odds of mortality or complications. In the hip fracture and extremity fracture groups, below-median income was not associated with significantly higher odds of mortality.

CONCLUSION

We found that rural patients with hip fracture have higher mortality compared to urban patients and that socioeconomic disparities in mortality after a polytrauma exist in urban settings. These results speak to the ongoing need to develop objective measures of disparity-sensitive healthcare and optimize trauma systems to better serve low-income patients and patients in rural areas.

Case report: An elderly woman with recurrent syncope after pacemaker implantation

Syncope caused by atrioventricular block may occur as a result of a cardiac vasodepressor reflex. This article reports on a case of recurrent syncope in an 80-year-old woman with high-grade atrioventricular block, documented by electrocardiographic monitoring after pacemaker implantation. Pacemaker testing revealed stable impedance and sensing but a clear increase in the ventricular capture threshold at outputs. This case is unusual because the patient's primary diagnosis was non-cardiac. However, a combination of high D-dimer, hypoxemia, and computerized tomography scan of the pulmonary artery confirmed the diagnosis of pulmonary embolism (PE). With 1 month of anticoagulant therapy, the ventricular capture threshold gradually dropped to the normal range and syncope resolved. This is the first report of an electrophysiological phenomenon detected by pacemaker testing in a patient with syncope arising from PE.

Bradycardia as a Rare Sign of Pulmonary Embolism: A Case Report of Pulmonary Embolism Diagnosis in Cardiac Arrest Using Point-of-Care Ultrasound

We describe a case of cardiac arrest with pulmonary embolism and deep venous thrombosis diagnosed by point-of-care ultrasound, which resulted in a favorable outcome. In this article, we have also delineated bradycardia as an atypical sign of pulmonary embolism and explained the potential mechanism behind it.

Clinical Utility of D-Dimer for Rule-Out or Rule-In of Venous Thromboembolism in Syncope

Fig. 1 Diagnostic performance of D-dimer using two different assays in patients presenting with syncope. A Left: Receiver-operating characteristic curves quantifying the diagnostic performance of Innovance® D-dimer (blue) and hs-Loci-Innovance® D-dimer (red) for the diagnosis of venous thromboembolism (VTE). Right: Clinical application of D-dimer using the 2-level Wells-score with age-adjusted¹ or fixed cutoffs versus the YEARS-algorithm with probability-adjusted cut offs². B Left: Specificity for different cufoffs of Innovance® D-dimer (blue) and hs-Loci-Innovance® D-dimer (red) for the diagnosis of venous thromboembolism (VTE). Right: Percentage of patients ruled-in and correctly identified VTE patients for different cutoffs of Innovance® D-dimer (blue) and hs-Loci-Innovance® D-dimer (red). ¹In patients 50 years or younger, D-dimer concentration < 0.5 mg/l was considered negative. For patients older than 50 years, we used the formula: age in years divided by 100. ²YEARS-algorithm: assessment of only three items from the Wells-score (clinical signs of deep vein thrombosis, hemoptysis, pulmonary embolism the most likely diagnosis) and using a D-dimer test threshold of 0.5 mg/l in presence, and 1.0 mg/l in absence of one of the YEARS-items.

Choosing Wisely in clinical practice: Embracing critical thinking, striving for safer care

In recent years, the Choosing Wisely and Less is More campaigns have gained growing attention in the medical scientific community. Several projects have been launched to facilitate confrontation among patients and physicians, to achieve better and harmless patient-centered care. Such initiatives have paved the way to a new "way of thinking." Embracing such a philosophy goes through a cognitive process that takes into account several issues. Medicine is a highly inaccurate science and physicians should deal with uncertainty. Evidence from the literature should not be accepted as it is but rather be translated into practice by medical practitioners who select treatment options for specific cases based on the best research, patient preferences, and individual patient characteristics. A wise choice requires active effort into minimizing the chance that potential biases may affect our clinical decisions. Potential harms and all consequences (both direct and indirect) of prescribing tests, procedures, or medications should be carefully evaluated, as well as patients' needs and preferences. Through such a cognitive process, a patient management shift is needed, moving from being centered on establishing a diagnosis towards finding the best management strategy for the right patient at the right time. Finally, while "thinking wisely," physicians should also "act wisely," being among the leading actors in facing upcoming healthcare challenges related to environmental issues and social discrepancies.

Developing and validating natural language processing algorithms for radiology reports compared to ICD-10 codes for identifying venous thromboembolism in hospitalized medical patients

BACKGROUND

Identifying venous thromboembolism (VTE) from large clinical and administrative databases is important for research and quality improvement.

OBJECTIVE

To develop and validate natural language processing (NLP) algorithms to identify VTE from radiology reports among general internal medicine (GIM) inpatients.

METHODS

This cross-sectional study included GIM hospitalizations between April 1, 2010 and March 31, 2017 at 5 hospitals in Toronto, Ontario, Canada. We developed NLP algorithms to identify pulmonary embolism (PE) and deep venous thrombosis (DVT) from radiologist reports of thoracic computed tomography (CT), extremity compression ultrasound (US), and nuclear ventilation-perfusion (VQ) scans in a training dataset of 1551 hospitalizations. We compared the accuracy of our NLP algorithms, the previously-published "simpleNLP" tool, and administrative discharge diagnosis codes (ICD-10-CA) for PE and DVT to the "gold standard" manual review in a separate random sample of 4000 GIM hospitalizations.

RESULTS

Our NLP algorithms were highly accurate for identifying DVT from US, with sensitivity 0.94, positive predictive value (PPV) 0.90, and Area Under the Receiver-Operating-Characteristic Curve (AUC) 0.96; and in identifying PE from CT, with sensitivity 0.91, PPV 0.89, and AUC 0.96. Administrative diagnosis codes and the simple NLP tool were less accurate for DVT (ICD-10-CA sensitivity 0.63, PPV 0.43, AUC 0.81; simpleNLP sensitivity 0.41, PPV 0.36, AUC 0.66) and PE (ICD-10-CA sensitivity 0.83, PPV 0.70, AUC 0.91; simpleNLP sensitivity 0.89, PPV 0.62, AUC 0.92).

CONCLUSIONS

Administrative diagnosis codes are unreliable in identifying VTE in hospitalized patients. We developed highly accurate NLP algorithms to identify VTE from radiology reports in a multicentre sample and have made the algorithms freely available to the academic community with a user-friendly tool (https://lks-chart.github.io/CHARTextract-docs/08-downloads/rulesets.html#venous-thromboembolism-vte-rulesets).

D-Dimer Tests in the Emergency Department: Current Insights

In the Emergency Medicine setting, D-dimer is currently employed in the diagnostic assessment of suspected venous thromboembolism and aortic syndrome. The nonspecific symptoms reported by patients, like chest pain, dyspnea or syncope, uncover a wide range of differential diagnosis, spanning from mild to life-threatening conditions. Therefore, we assumed the perspective of the Emergency Physician and, in this narrative review, we reported a brief presentation of the epidemiology of these symptoms and the characteristics of patients, in whom we could suspect the aforementioned pathologies. We also reported in which patients D-dimer gives useful information. In fact, when the probability of the disease is high, the D-dimer level is futile. On the contrary, given the low specificity of the test, when the probability of the disease is very low, a false-positive value of the D-dimer only increases the risk of overtesting. Patients with low to moderate probability really benefit from the D-dimer testing, in order to prevent the execution of expensive and potentially dangerous imaging tests. In the second part of the review, we focused on the prognostic value of the test in septic patients. The early prognostic stratification of septic patients remains a challenge for the Emergency Physician, in the absence of a definite biomarker or score to rely on. Therefore, we need several parameters for the early identification of patients at risk of an adverse prognosis and the D-dimer may play a role in this demanding task. SARS COVID-19 patients represent an emerging reality, where the role of the D-dimer for prognostic stratification could be relevant. In fact, in patients with severe forms of this disease, the D-dimer reaches very high values, which appear to parallel the course of respiratory failure. Whether the test may add useful information for the management of these patients remains to be determined.

Syncope Time Frames for Adverse Events after Emergency Department Presentation: An Individual Patient Data Meta-Analysis

Background and Objectives: Knowledge of the incidence and time frames of the adverse events of patients presenting syncope at the ED is essential for developing effective management strategies. The aim of the present study was to perform a meta-analysis of the incidence and time frames of adverse events of syncope patients. Materials and Methods: We combined individual patients’ data from prospective observational studies including adult patients who presented syncope at the ED. We assessed the pooled rate of adverse events at 24 h, 72 h, 7–10 days, 1 month and 1 year after ED evaluation. Results: We included nine studies that enrolled 12,269 patients. The mean age varied between 53 and 73 years, with 42% to 57% females. The pooled rate of adverse events was 5.1% (95% CI 3.4% to 7.7%) at 24 h, 7.0% (95% CI 4.9% to 9.9%) at 72 h, 8.4% (95% CI 6.2% to 11.3%) at 7–10 days, 10.3% (95% CI 7.8% to 13.3%) at 1 month and 21.3% (95% CI 15.8% to 28.0%) at 1 year. The pooled death rate was 0.2% (95% CI 0.1% to 0.5%) at 24 h, 0.3% (95% CI 0.1% to 0.7%) at 72 h, 0.5% (95% CI 0.3% to 0.9%) at 7–10 days, 1% (95% CI 0.6% to 1.7%) at 1 month and 5.9% (95% CI 4.5% to 7.7%) at 1 year. The most common adverse event was arrhythmia, for which its rate was 3.1% (95% CI 2.0% to 4.9%) at 24 h, 4.8% (95% CI 3.5% to 6.7%) at 72 h, 5.8% (95% CI 4.2% to 7.9%) at 7–10 days, 6.9% (95% CI 5.3% to 9.1%) at 1 month and 9.9% (95% CI 5.5% to 17) at 1 year. Ventricular arrhythmia was rare. Conclusions: The risk of death or life-threatening adverse event is rare in patients presenting syncope at the ED. The most common adverse events are brady and supraventricular arrhythmias, which occur during the first 3 days. Prolonged ECG monitoring in the ED in a short stay unit with ECG monitoring facilities may, therefore, be beneficial.

Prevalence of venous thromboembolism in admissions and readmissions with and without syncope: a nationwide cohort study

AIMS

The Pulmonary Embolism in Syncope Italian Trial reported 17.3% prevalence of pulmonary embolism (PE) in patients admitted with syncope. We investigated the prevalence of venous thromboembolism [VTE, including PE and deep vein thrombosis (DVT)] in syncope vs. non-syncope admissions and readmissions, and if syncope is an independent predictor of VTE.

METHODS AND RESULTS

We conducted an observational study of index admissions of the 2013-14 Nationwide Readmission Database. We excluded patients <18 years, December discharges, died during hospitalization, hospital transfers, and missing length of stay. Encounters were stratified by the presence or absence of DVT/PE and syncope diagnoses. Multivariable logistic regression analysis was used to evaluate the association between syncope and VTE. There were 38 655 570 admissions, of whom 285 511 had syncope. In the overall cohort, syncope occurred in 1.6% of VTE and 1.8% in non-VTE admissions. In a multivariable model, syncope was associated with a lower prevalence of VTE [odds ratio (OR) 0.76, 95% confidence interval (CI) 0.75-0.78; P < 0.001]. In index syncope vs. non-syncope admissions, the prevalence of DVT, PE, and VTE were 0.4 ± 0.06% vs. 1.3 ± 0.12%, 0.2 ± 0.04% vs. 1.2 ± 0.11%, and 0.5 ± 0.07% vs. 2.1 ± 0.14% (all P < 0.001), respectively. At 30 days, the prevalence of DVT, PE, and VTE in syncope vs. non-syncope were 2.2 ± 0.14% vs. 2.1 ± 0.14% (P = 0.38), 1.4 ± 0.12% vs. 1.2 ± 0.11% (P = 0.01), and 2.6 ± 0.17% vs. 3.0 ± 0.17% (P = 0.99), respectively.

CONCLUSION

Syncope admissions were associated with a lower prevalence of VTE as compared to non-syncope admissions. Syncope should not trigger an automatic PE workup, rather, should be put into context of patient presentation.

Syncope in pulmonary embolism: a retrospective cohort study

OBJECTIVE

To determine the prevalence of syncope or collapse in pulmonary embolism (PE).

METHODS

A retrospective cohort study was conducted. We examined the frequency with which syncope or collapse (presyncope) occurred alone or with other symptoms and signs in an unselected series of 224 patients presenting to a district general hospital with PE between September 2012 and March 2016. Confirmation of PE was by CT pulmonary angiogram in each case.

RESULTS

Our cohort of 224 patients comprised 97 men and 127 women, average age 66 years with age range of 21-94 years. Syncope or collapse was one of several symptoms and signs that led to a diagnosis of PE in 22 patients (9.8%) but was never the sole presenting feature. In descending order, these other clinical features were hypoxaemia (17 patients), dyspnoea (12), chest pain (9), tachycardia (7) and tachypnoea (7). ECG abnormalities reported to occur more commonly in PE were found in 13/17 patients for whom ECGs were available. Patients with PE presenting with syncope or collapse were judged to have a large clot load in 15/22 (68%) cases.

CONCLUSION

Syncope was a frequent presenting symptom in our study of 224 consecutive patients with PE but was never the sole clinical feature. It would be difficult to justify routine testing for PE in patients presenting only with syncope or collapse.

The Prognostic Value of Syncope on Mortality in Patients With Pulmonary Embolism: A Systematic Review and Meta-analysis

STUDY OBJECTIVE

Syncope is a presenting symptom in 10% to 20% of patients with pulmonary embolism. We perform a meta-analysis to clarify the prognostic value of syncope on short-term mortality in pulmonary embolism patients and its association with hemodynamic instability.

METHODS

PubMed, EMBASE, and the Cochrane Library were searched up until January 7, 2020. Studies reporting inhospital or 30-day mortality of adults with pulmonary embolism with and without syncope were included. Quality of included studies was evaluated with the Quality in Prognosis Studies tool. Meta-analysis was conducted to derive pooled odds ratios (ORs) and risk differences for the relation of syncope with mortality and hemodynamic instability. To study the influence of hemodynamic instability on the association between syncope and mortality, meta-regression was performed.

RESULTS

Search and selection resulted in 26 studies, of which 20 were pooled, involving 9,419 of 335,120 patients (3%) with syncope. Syncope was associated with higher mortality (OR 1.82; 95% confidence interval [CI] 1.14 to 2.90; I2 88%; risk difference 4% [95% CI 1% to 8%]) and higher prevalence of hemodynamic instability (OR 4.36; 95% CI 2.27 to 8.37; I2 93%; risk difference 12% [95% CI 7% to 18%]). OR for mortality in patients with pulmonary embolism with syncope versus without it was higher in the presence of a larger difference in hemodynamic instability between groups (coefficient 0.05; 95% CI 0.01 to 0.09).

CONCLUSION

The association between syncope and short-term mortality in patients with pulmonary embolism is explained by a difference in hemodynamic instability. This emphasizes the importance of risk stratification by hemodynamic status in pulmonary embolism patients with and without syncope.

Sex-related difference in the prognostic value of syncope for 30-day mortality among hospitalized pulmonary embolism patients

INTRODUCTION

Recent studies report that syncope is not a significant predictor of 30-day mortality in pulmonary embolism (PE) patients, yet some data suggest sex-related differences may be relevant.

OBJECTIVES

To evaluate sex-specific prediction significance of syncope for 30-day mortality in PE patients.

METHODS

A multicentric, retrospective, observational, registry-based study on consecutive PE patients was undertaken. Patients were allocated into either a men or a women group before comparisons were made between patients with syncope and those without syncope. A sex-related prediction of the significance of syncope for 30-day mortality was evaluated.

RESULTS

Overall 588 patients [294 (50%) men and 294 (50%) women] were included within the study. Among men, patients with syncope were older and had significantly higher parameters of increased 30-day mortality then patients without syncope. Within the same group, however, difference in the 30-day mortality rate was not significant (log rank P = .942). In contrast to the men, fewer differences in admission characteristics were noticed among women, but those with syncope had significantly increased signs of the right ventricular dysfunction and increased 30-day mortality rate, as compared with those without syncope (log rank P = .025). After adjustment for age in a Cox regression analysis, syncope was a significant predictor of 30-day mortality in women (HR = 2.01, 95%CI 1.02-3.95).

CONCLUSION

Although syncope is associated with other predictors of higher early mortality in both male and female PE patients, only in women it is a significant predictor of 30-day mortality.

The Current and Future Hospitalization Cost Burden of Syncope in Canada

BACKGROUND

Single-center studies have shown the high costs associated with the hospital evaluation of syncope. National cost estimates for syncope-related hospitalizations are sparse, and none exist in Canada.

METHODS

The Canadian Institute for Health Information Discharge Abstract Database was used to identify acute care hospitalizations with a primary diagnosis of syncope between fiscal years (FY) 2004 and 2015 in all provinces and territories (except Quebec). We used multiple linear regression to calculate the trends in prevalence of hospital admissions and generalized linear regression to estimate the costs of a hospitalization. The syncope hospitalization rate and the cost per hospitalization in Quebec were assumed to be the average of the rest of the country. The future hospitalization cost burden of syncope was projected to 2030.

RESULTS

There were 128,263 hospitalizations for a primary diagnosis of syncope over the 10-year study period, resulting in a total cost of $619.9 million (Canadian). An estimate of 41,044 syncope hospitalizations occurred in Quebec, costing $198.7 million. The total hospitalization cost of syncope in Canada was estimated at $818.5 million. The annual costs of syncope hospitalizations increased from $66.6 to $68.5 million between FY2004 and FY2015, respectively, and are projected to increase to $87.1 million in 2030.

CONCLUSION

Hospitalization costs for syncope in Canada are high and rising. Research is needed to identify opportunities to deliver more efficient and cost-effective care.

Sudden unresponsive patient with normal vital signs: what is going on?

PURPOSE OF REVIEW

To summarize the differential diagnosis and diagnostic approach of sudden unresponsiveness with normal vital signs in various settings, including the ICU.

RECENT FINDINGS

Sudden unresponsiveness may be either transient or persistent, and may result from primary brain diseases or nonstructural systemic conditions. Life-threatening causes should always be discriminated from those more benign. Regional epidemiology, for example regarding intoxications, and evolving therapeutic management, for example for ischemic stroke, should always be taken into account for optimal opportunity for rapid diagnosis and best management.

SUMMARY

Sudden unresponsiveness with normal vital signs should trigger immediate and focused diagnostic evaluation to find or exclude those conditions requiring urgent, and possibly life-saving, management.

Thirty-day readmissions due to Venous thromboembolism in patients discharged with syncope

A recent study found that approximately 1 in every 6 patients hospitalized for the 1st episode of syncope had an underlying pulmonary embolism (PE). As current guidelines do not strongly emphasize evaluation for PE in the workup of syncope, we hypothesize that there might be a higher rate of 30-day readmission due to untreated venous thromboembolism (VTE). The objective of this study is to measure the 30-day readmission rate due to VTE and identify predictors of 30-day readmission with VTE among syncope patients. We identified patients admitted with syncope with ICD9 diagnoses code 780.2 in the Nationwide Readmission Database (NRD-2013), Healthcare Cost and Utilization Project (HCUP). The 30-day readmission rate was calculated using methods described by HCUP. Logistic-regression was used to identify predictors of 30-day readmission with VTE. Discharge weights provided by HCUP were used to generate national estimates. In 2013, NRD included 207,339 eligible patients admitted with syncope. The prevalence rates of PE and DVT were 1.1% and 1.4%, respectively. At least one syncope associated condition was present in 60.9% of the patients. Among the patients who were not diagnosed with VTE during index admission for syncope (N = 188,015), 30-day readmission rate with VTE was 0.5% (0.2% with PE and 0.4% with DVT). In conclusion, low prevalence of VTE in patients with syncope and extremely low 30-day readmission rate with VTE argues against missed diagnoses of VTE in index admission for syncope. These results warrant further studies to determine clinical impact of work up for PE in syncope patients without risk factors.

Diagnostic yield of pulmonary embolism testing in patients presenting to the emergency department with syncope

BACKGROUND

Syncope occurs in 1 in 4 people during their lifetime and accounts for 1% to 1.5% of emergency department (ED) visits. Most causes of syncope are benign, but syncope may be caused by life-threatening conditions including pulmonary embolism (PE) in up to 2% of cases. A recent publication reported the prevalence of PE in patients with syncope to be over 17%.

AIMS

We sought to determine the frequency and diagnostic yield of testing for PE in patients presenting to the ED with syncope in our large, integrated health care system.

METHODS

We performed a retrospective, longitudinal cohort study of patients who presented with syncope to EDs within a 21-hospital integrated health care system from 2010 to 2015 to find the frequency and diagnostic yield of testing for PE in patients with syncope at index ED visit and within 180 days afterward.

RESULTS

We screened 2 749 371 ED encounters to find 32 440 (1.2%) with syncope. Median age was 52 (interquartile range, 31-71), 57.5% were female, and 90% were Caucasian. PE was diagnosed on the index ED visit in 259 (0.8%; 95% confidence interval [CI], 0.7%-0.9%) cases. Assessment for suspected PE with D-dimer occurred in 5089 (15.7%) patients, and 2338 (7.2%) underwent computed tomography pulmonary angiography (CTPA). The yield of CTPA was 7.9%. PE was detected in 2.2% in whom a D-dimer was performed. From index visit to 180 days, 467 (1.4%; 95% CI, 1.3%-1.6%) patients were diagnosed with a PE, and 1051 (3.2%, 95% CI, 3.0%-3.4%) patients died.

CONCLUSION

Diagnostic testing for PE is frequent in patients with syncope presenting to the EDs of a large, integrated health care system. The yield of diagnostic testing is low.

Massive Fatal Pulmonary Embolism While on Therapeutic Heparin Drip

Venous thromboembolism (VTE) includes deep venous thrombosis (DVT) and pulmonary embolism (PE). In this article, we present a case of a patient with an acute DVT who was treated with a therapeutic heparin drip, then developed syncope while in the hospital and found to have massive bilateral PEs. This case aims to arouse the medical staff’s awareness of the VTE diagnosis even if the patient is fully anticoagulated. We review the indications for DVT hospitalization, heparin infusion monitoring, risk factors for developing PE from DVT, mechanisms of developing PE from DVT while on therapeutic anticoagulation, and signs and treatment of massive PE.

Opportunistic Diagnosis of Extensive Pulmonary Embolus Following "COVID-19 Blood Battery" in Very Frail Older Patients

D-dimer is routinely measured to exclude the diagnosis of venous thromboembolism and is its main biomarker. Appropriate age-adjusted D-dimer testing improves D-dimer specificity, could decrease inappropriate CT pulmonary angiograms in the older person, and prevent unnecessary radiation exposure. A "COVID-19 blood battery", designed to increase the efficiency of evaluation of COVID-19 suspected patients is used in our institution. It includes D-dimers which are elevated in COVID-19 infections and potentially an index of severe infection. These 3 very frail patients presented late to the emergency department, all acutely and non-specifically unwell, with high prevalence of comorbidities and were transferred in by ambulance. They were triaged to the COVID-19 pathway of our hospital, and subsequently had negative COVID-19 swabs. All had an incidental finding of markedly elevated D-dimers, with potential causes of their symptoms other than pulmonary embolus. They were transferred to an acute geriatric ward specifically designated to manage older patients (>75years) who had negative nasopharyngeal swab results. They were all ultimately diagnosed with extensive pulmonary emboli with evidence of raised pulmonary pressures on CTPA and/or echocardiogram. It is possible that these patients had false negative COVID-19 swabs. Allowing for the novel nature of COVID-19, prospective evaluation for new symptoms and complications such as thromboembolic disease in those affected by milder symptoms should be considered. In the absence of clinical improvement following treatment of other conditions in frail older patients, D-dimer testing could be indicated with pursuit of specific diagnostic evaluation for venous thromboembolism when significantly elevated.

Factors influencing harmonized health data collection, sharing and linkage in Denmark and Switzerland: A systematic review

Introduction

The digitalization of medicine has led to a considerable growth of heterogeneous health datasets, which could improve healthcare research if integrated into the clinical life cycle. This process requires, amongst other things, the harmonization of these datasets, which is a prerequisite to improve their quality, re-usability and interoperability. However, there is a wide range of factors that either hinder or favor the harmonized collection, sharing and linkage of health data.

Objective

This systematic review aims to identify barriers and facilitators to health data harmonization—including data sharing and linkage—by a comparative analysis of studies from Denmark and Switzerland.

Methods

Publications from PubMed, Web of Science, EMBASE and CINAHL involving cross-institutional or cross-border collection, sharing or linkage of health data from Denmark or Switzerland were searched to identify the reported barriers and facilitators to data harmonization.

Results

Of the 345 projects included, 240 were single-country and 105 were multinational studies. Regarding national projects, a Swiss study reported on average more barriers and facilitators than a Danish study. Barriers and facilitators of a technical nature were most frequently reported.

Conclusion

This systematic review gathered evidence from Denmark and Switzerland on barriers and facilitators concerning data harmonization, sharing and linkage. Barriers and facilitators were strictly interrelated with the national context where projects were carried out. Structural changes, such as legislation implemented at the national level, were mirrored in the projects. This underlines the impact of national strategies in the field of health data. Our findings also suggest that more openness and clarity in the reporting of both barriers and facilitators to data harmonization constitute a key element to promote the successful management of new projects using health data and the implementation of proper policies in this field. Our study findings are thus meaningful beyond these two countries.

Prevalence of pulmonary embolism in emergency department patients with isolated syncope: a prospective cohort study

BACKGROUNDS

Paramount to guide the diagnostic strategy, the prevalence of pulmonary embolism in patients with syncope and no other symptoms is uncertain. We aimed to assess the pulmonary embolism prevalence in patients that present to the emergency department (ED) with syncope and no chest pain nor dyspnea.

METHODS

Multicenter prospective cohort study in seven EDs in France. Adult patients who presented to the ED with syncope (transient loss of consciousness) were included. Patients with chest pain or dyspnea were excluded. Included patients underwent formal work-up for pulmonary embolism, including D-dimer testing and further imaging if positive. Cases of pulmonary embolism were adjudicated by two independent expert radiologists with the review of imaging studies. Secondary objectives included the pulmonary embolism prevalence in the subgroup of patients with cancer, in patients with negative Pulmonary Embolism Rule Out criteria (PERC) score, and according to the clinical probability assessed either by Wells or revised Geneva score.

RESULTS

We analyzed 411 patients, in whom 128 (31%) underwent a computed tomographic pulmonary angiogram and 9 (2%) a ventilation-perfusion scan. A pulmonary embolism was confirmed in nine patients (prevalence of 2.2%, 95% confidence interval, 1.1-4.3%), including one subsegmental pulmonary embolism. This prevalence was of 18% (3-52%) in patients with cancer and 0.7% (0.1-4%) in PERC negative patients.

CONCLUSION

In our sample of patients with isolated syncope, the prevalence of pulmonary embolism was 2.2%. This value is not sufficiently low to negate the requirement for a formal work up in the ED, even in the absence of chest pain or dyspnea. However, the large confidence interval precludes any strong conclusion.

Impact of De-Identification on Clinical Text Classification Using Traditional and Deep Learning Classifiers

Clinical text de-identification enables collaborative research while protecting patient privacy and confidentiality; however, concerns persist about the reduction in the utility of the de-identified text for information extraction and machine learning tasks. In the context of a deep learning experiment to detect altered mental status in emergency department provider notes, we tested several classifiers on clinical notes in their original form and on their automatically de-identified counterpart. We tested both traditional bag-of-words based machine learning models as well as word-embedding based deep learning models. We evaluated the models on 1,113 history of present illness notes. A total of 1,795 protected health information tokens were replaced in the de-identification process across all notes. The deep learning models had the best performance with accuracies of 95% on both original and de-identified notes. However, there was no significant difference in the performance of any of the models on the original vs. the de-identified notes.

Automated detection of altered mental status in emergency department clinical notes: a deep learning approach

BACKGROUND

Machine learning has been used extensively in clinical text classification tasks. Deep learning approaches using word embeddings have been recently gaining momentum in biomedical applications. In an effort to automate the identification of altered mental status (AMS) in emergency department provider notes for the purpose of decision support, we compare the performance of classic bag-of-words-based machine learning classifiers and novel deep learning approaches.

METHODS

We used a case-control study design to extract an adequate number of clinical notes with AMS and non-AMS based on ICD codes. The notes were parsed to extract the history of present illness, which was used as the clinical text for the classifiers. The notes were manually labeled by clinicians. As a baseline for comparison, we tested several traditional bag-of-words based classifiers. We then tested several deep learning models using a convolutional neural network architecture with three different types of word embeddings, a pre-trained word2vec model and two models without pre-training but with different word embedding dimensions.

RESULTS

We evaluated the models on 1130 labeled notes from the emergency department. The deep learning models had the best overall performance with an area under the ROC curve of 98.5% and an accuracy of 94.5%. Pre-training word embeddings on the unlabeled corpus reduced training iterations and had performance that was statistically no different than the other deep learning models.

CONCLUSION

This supervised deep learning approach performs exceedingly well for the detection of AMS symptoms in clinical text in our environment. Further work is needed for the generalizability of these findings, including evaluation of these models in other types of clinical notes and other environments. The results seem promising for the ultimate use of these types of classifiers in combination with other information derived from the electronic health records as input for clinical decision support.

Prevalence and Predictors of Pulmonary Embolism in Hospitalized Patients with Syncope

OBJECTIVES

Approximately one in six patients hospitalized with syncope have pulmonary embolism (PE), according to the PE in Syncope Italian Trial study. Subsequent studies using administrative data have reported a PE prevalence of <3%. The aim of the study was to determine the prevalence and predictors of PE in hospitalized patients with syncope.

METHODS

We retrospectively reviewed the records of patients who were hospitalized in the MedStar Washington Hospital Center between May 1, 2015 and June 30, 2017 with deep venous thrombosis, PE, and syncope. Only patients who presented to the emergency department with syncope were included in the final analysis. PE was diagnosed by either positive computed tomographic angiography or a high-probability ventilation-perfusion scan. Univariate and multivariate logistic regressions were used to assess the associations between clinical variables and the diagnosis of PE in patients with syncope.

RESULTS

Of the 408 patients hospitalized with syncope (mean age, 67.5 years; 51% men [N = 208]), 25 (6%) had a diagnosis of PE. Elevated troponin levels (odds ratio 6.6, 95% confidence interval 1.9-22.9) and a dilated right ventricle on echocardiogram (odds ratio 6.9, 95% confidence interval 2.0-23.6) were independently associated with the diagnosis of PE. Age, active cancer, and history of deep venous thrombosis were not associated with the diagnosis of PE.

CONCLUSIONS

The prevalence of PE in this study is approximately one-third of the reported prevalence in the PE in Syncope Italian Trial study and almost three times the value reported in administrative data-based studies. PE should be suspected in patients with syncope and elevated troponin levels or a dilated right ventricle on echocardiogram.

Pearls and Myths in the Evaluation of Patients with Suspected Acute Pulmonary Embolism

Significant improvement has been achieved in diagnostic accuracy, validation of probability scores, and standardized treatment algorithms for patients with suspected acute pulmonary embolism. These developments have provided the tools for a safe and cost-effective management for most of these patients. In our experience, however, the presence of medical myths and ongoing controversies seem to hinder the implementation of these tools in everyday clinical practice. This review provides a selection of such dilemmas and controversies and discusses the published evidence beyond them. By doing so, we try to overcome these dilemmas and suggest pragmatic approaches guided by the available evidence and current guidelines.

Prospective Study of Pulmonary Embolism Presenting as Syncope

BACKGROUND

Syncope represents a common condition among the general population. It is also a frequent complaint of patients in the emergency department (ED). Pulmonary embolism (PE) considers a differential diagnosis, particularly in a case of syncope without chest pain.

STUDY QUESTION

What is the prevalence of PE among patients who presented an episode of syncope to the ED and among those hospitalized for syncope in a tertiary care hospital?

STUDY DESIGN

From January 2012 to December 2017, we conducted a prospective observational study among adult patients presenting themselves to the ED consecutively or admitted for syncope.

MEASURES AND OUTCOMES

Syncope and PE were defined by professional guidelines. PE was ruled out in patients who had a low pretest clinical probability, as per Wells score and a negative D-dimer assay. In other patients, computed tomography pulmonary angiography was performed.

RESULTS

Seventeen thousand eight-two patients (mean age 71.3 ± 13.24 years) visited the ED for syncope. PE was detected in 45 patients (mean age 65.75 ± 9.45 years): 4 with low risk, 26 with intermediate risk, and 15 with high risk. The prevalence of PE in those hospitalized with syncope was 11.47%, which is 45 of 392 (confidence interval 95% 8.48-15.04), and was 2.52%, 45 of 1782 (confidence interval 95% 1.8-3.3), in patients presenting with syncope to the ED. The location of the embolus was bilateral in 24 patients (53.33%), in a main pulmonary artery in 10 (22.22%), in a lobar artery in 10 (22.22%), and in a segmental artery in 1 (2.22%).

CONCLUSIONS

The occurrence of syncope, if not explained otherwise, should alert one to consider PE as a differential diagnosis. PE rate, presenting as syncope, is the highest in patients with large thrombi, which is responsible for bilateral or proximal obstruction in a main or lobar pulmonary artery.

Syncope in haemodynamically stable and unstable patients with acute pulmonary embolism - Results of the German nationwide inpatient sample

Syncope in pulmonary embolism (PE) could be the first sign of haemodynamic compromise. We aimed to investigate pathomechanisms of syncope and its impact on mortality. For this study, patients (aged ≥ 18years) were selected by screening the German nationwide inpatient sample for PE and stratified included patients by syncope (2011–2014). We analysed predictors of syncope in haemodynamically stable PE. Impact of syncope on in-hospital mortality in haemodynamically stable and unstable PE and benefit of systemic thrombolysis in haemodynamically stable PE with syncope (PE + Syncope) were analyzed. The German nationwide inpatient sample comprised 293,640 (84.9%) haemodynamically stable and 52,249 (15.1%) unstable PE patients; among them 2.3% had syncope. Right ventricular dysfunction (RVD) was a key predictor for syncope. In-hospital mortality-rate was lower in haemodynamically stable (6.4% vs. 7.6%, P < 0.001) and unstable PE + Syncope than in PE−Syncope (48.4% vs. 55.5%, P < 0.001) with reduced risk for in-hospital death in stable (OR 0.68 (95%CI 0.61–0.75), P < 0.001) and unstable (OR 0.69 (95% CI 0.62–0.78), P < 0.001) inpatients independent of age and sex. Haemodynamically stable PE + Syncope patients were more often treated with systemic thrombolysis (3.1% vs. 2.1%, P < 0.001). Systemic thrombolysis was associated with reduced in-hospital mortality in haemodynamically stable PE + Syncope (1.9% vs. 6.6%, P = 0.004) independently of age, RVD and tachycardia (OR 0.30 (95%CI 0.11–0.82), P = 0.019). In conclusion, in-hospital mortality was 6.4% in haemodynamically stable PE + Syncope. Haemodynamically stable PE + Syncope patients were more often treated with systemic thrombolysis and showed a trend to improved survial.

Variation in diagnostic testing for older patients with syncope in the emergency department

BACKGROUND

Older adults presenting with syncope often undergo intensive diagnostic testing with unclear benefit. We determined the variation, frequency, yield, and costs of tests obtained to evaluate older persons with syncope.

METHODS

We conducted a prospective, multicenter observational cohort study in 11 academic emergency departments in the United States of 3686 patients aged ≥60 years presenting with syncope or presyncope. We measured the frequency, variation, yield, and costs (based on Medicare payment tables) of diagnostic tests performed at the index visit.

RESULTS

While most study rates were similar across sites, some were notably discordant (e.g., carotid ultrasound: mean 9.5%, range 1.1% to 49.3%). The most frequently-obtained diagnostic tests were initial troponin (88.6%), chest x-ray (75.1%), head CT (42.5%) and echocardiogram (35.5%). The yield or proportion of abnormal findings by diagnostic test ranged from 1.9% (electrocardiogram) to 42.0% (coronary angiography). Among the most common tests, echocardiogram had the highest proportion of abnormal results at 22.1%. Echocardiogram was an outlier in total cost at $672,648, and had a cost per abnormal test of $3129.

CONCLUSION

Variation in diagnostic testing in older patients presenting with syncope exists. The yield and cost per abnormal result for common tests obtained to evaluate syncope are also highly variable. Selecting tests based on history and examination while also prioritizing less resource intensive and higher yield tests may ensure a more informed and cost-effective approach to evaluating older patients with syncope.

[Tips for taking the medical history in patients with syncope]

Transient loss of consciousness represents one of the most frequent reasons for patients to present in the emergency room. Already at the very beginning, the diagnostic work-up is faced with fundamental questions: (1) Was it really a loss of consciousness? (2) Which department (neurology, cardiology, or others) should check the patient? (3) Is an in-hospital diagnostic work-up required? These questions can be answered from a meticulous patient history which needs to be adjusted to the individual case but also has to systematically go through a list of questions. Patient history has to clarify whether syncope was present. Nonsyncopal events such as falls, transient global amnesia, epilepsy, psychogenic pseudosyncope, transient ischemic attack and drop attacks should be distinguished. In a second step, the four groups of causes of syncope can be assessed. Neurocardiogenic reflex syncope usually occurs with typical prodromes in typical situations in (younger) patients without heart disease. Orthostasis always occurs in upright position, typically associated with standing up and in patients treated with antihypertensive drugs. Arrhythmogenic syncope frequently shows an abrupt onset without prodromes, associated with injury and with palpitations or fast heart beat before the attack, in older patients frequently associated with known heart disease, in young patients without heart disease frequently with a family history positive for arrhythmias or sudden cardiac death. A positive history of structural cardiovascular disease should be considered as a cause of syncope, particularly if it occurs during exercise or in supine position, or is associated with chest pain or dyspnea. This review summarizes the most important questions that can elucidate the cause of syncope.

The incidence of acute pulmonary embolism following syncope in anticoagulant-naïve patients: A retrospective cohort study

BACKGROUND

A recently published, large prospective study showed unexpectedly high prevalence of acute pulmonary embolism (APE) among patients hospitalized for syncope. In such a case, a high incidence of recurrent pulmonary embolism is expected among patients who were discharged without APE workup.

OBJECTIVES

To determine the incidence of symptomatic APE among patients hospitalized for a first episode of syncope and discharged without APE workup or anticoagulation.

METHODS

This retrospective cohort study included patients hospitalized at Rambam Health Care Campus between January 2006 and February 2017 with a primary admission diagnosis of syncope, who were not investigated for APE and were not taking anticoagulants. The patients were followed up for up to three years after discharge. The occurrence of venous thromboembolism (VTE) during the follow-up period was documented.

RESULTS

The median follow-up duration was 33 months. 1,126 subjects completed a three-year follow-up. During this period, 38 patients (3.38%) developed VTE, 17 (1.51%) of them had APE. The cumulative incidence of VTE and APE was 1.9% (95% CI 1.3%-2.5%) and 0.9% (95% CI 0.4%-1.3%) respectively. Only seven subjects developed APE during the first year of follow-up. The median times from the event of syncope to the development of APE and VTE were 18 and 19 months respectively.

CONCLUSIONS

The cumulative incidence of VTE during a three-year follow-up period after an episode of syncope is low. In the absence of clinical suspicion, a routine diagnostic workup for APE in patients with syncope cannot be recommended.