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.

Management of high-risk pulmonary embolism in the emergency department: A narrative review

BACKGROUND

High-risk pulmonary embolism (PE) is a complex, life-threatening condition, and emergency clinicians must be ready to resuscitate and rapidly pursue primary reperfusion therapy. The first-line reperfusion therapy for patients with high-risk PE is systemic thrombolytics (ST). Despite consensus guidelines, only a fraction of eligible patients receive ST for high-risk PE.

OBJECTIVE

This review provides emergency clinicians with a comprehensive overview of the current evidence regarding the management of high-risk PE with an emphasis on ST and other reperfusion therapies to address the gap between practice and guideline recommendations.

DISCUSSION

High-risk PE is defined as PE that causes hemodynamic instability. The high mortality rate and dynamic pathophysiology of high-risk PE make it challenging to manage. Initial stabilization of the decompensating patient includes vasopressor administration and supplemental oxygen or high-flow nasal cannula. Primary reperfusion therapy should be pursued for those with high-risk PE, and consensus guidelines recommend the use of ST for high-risk PE based on studies demonstrating benefit. Other options for reperfusion include surgical embolectomy and catheter directed interventions.

CONCLUSIONS

Emergency clinicians must possess an understanding of high-risk PE including the clinical assessment, pathophysiology, management of hemodynamic instability and respiratory failure, and primary reperfusion therapies.

A Novel Tool for Predicting an Abnormal Echocardiogram in Patients with Pulmonary Embolism: The PEACE Score

BACKGROUND

Transthoracic echocardiography (TTE) is an essential tool for risk-stratifying patients with pulmonary embolism (PE), but its availability is limited, often requiring hospitalization. Minimal research exists evaluating clinical and laboratory criteria to predict lack of abnormal TTE findings.

OBJECTIVE

We aimed to identify predictors associated with abnormal TTE results in patients with PE to potentially identify those safe for early discharge.

METHODS

In this retrospective study, we analyzed an existing database of patients with venous thromboembolism (VTE) at two academic emergency departments, including adult patients with confirmed PE who underwent TTE. The primary goal was to develop and validate a score predicting abnormal TTE, defined as presence of one of the following: right ventricle (RV) dilatation or hypokinesis, septal flattening, right heart thrombus in transit, or ejection fraction < 50%. Variables were demographic characteristics, symptoms, computed tomography (CT) RV strain, troponin T, and N-terminal prohormone of brain natriuretic peptide (NTproBNP). Stepwise logistic regression was used to identify variables independently associated with abnormal TTE. Model discrimination was evaluated using area under the curve (AUC) of the receiver operating characteristic curve. A clinical prediction rule was developed.

RESULTS

530 of 2235 patients were included; 56% (297 of 530) had an abnormal TTE. The following six variables were independently associated with abnormal TTE: dyspnea, dizziness, troponin T ≥ 0.1 ng/mL, NTproBNP > 900 pg/mL, CT RV strain, and nonsubsegmental PE. A clinical prediction rule using these six criteria yielded scores between 0 and 7, performing well with AUC of 0.80 (95% CI 0.79-0.80). A score of 1 was 99.7% sensitive in identifying no abnormality. A score ≥ 5 was 98% specific for an abnormality.

CONCLUSIONS

The PEACE (Pulmonary Embolism and Abnormal Cardiac Echocardiogram) criteria, composed of six variables, is highly effective in predicting abnormal TTE in patients with PE, potentially identifying who is safe for early discharge from the hospital.

Addressing the rising trend of high-risk pulmonary embolism mortality: Clinical and research priorities

BACKGROUND

Deaths from high-risk pulmonary embolism (PE) appear to have increased in the US over the last decade. Modifiable risks contributing to this worrisome trend present opportunities for physicians, researchers, and healthcare policymakers to improve care.

METHODS

We sought to contextualize contemporary, high-risk PE epidemiology and examine clinical trials, quality improvement opportunities, and healthcare policy initiatives directed at reducing mortality.

RESULTS

We observed significant and modifiable excess mortality due to high-risk PE. We identified several opportunities to improve care including: (1) rapid translation of forthcoming data on reperfusion strategies into clinical practice; (2) improved risk stratification tools; (3) quality improvement initiatives to address presumptive anticoagulation practice gaps; and (3) adoption of health policy initiatives to establish pulmonary embolism response teams and address the social determinants of health.

CONCLUSION

Addressing knowledge and practice gaps in intermediate and high-risk PE management must be prioritized and informed by forthcoming high-quality data. Implementation efforts are needed to improve acute PE management and resolve treatment disparities.

Multi-ancestry polygenic risk scores for venous thromboembolism

Venous thromboembolism (VTE) is a significant contributor to morbidity and mortality, with large disparities in incidence rates between Black and White Americans. Polygenic risk scores (PRSs) limited to variants discovered in genome-wide association studies in European-ancestry samples can identify European-ancestry individuals at high risk of VTE. However, there is limited evidence on whether high-dimensional PRS constructed using more sophisticated methods and more diverse training data can enhance the predictive ability and their utility across diverse populations. We developed PRSs for VTE using summary statistics from the International Network against Venous Thrombosis (INVENT) consortium GWAS meta-analyses of European- (71,771 cases and 1,059,740 controls) and African-ancestry samples (7,482 cases and 129,975 controls). We used LDpred2 and PRSCSx to construct ancestry-specific and multi-ancestry PRSs and evaluated their performance in an independent European- (6,261 cases and 88,238 controls) and African-ancestry sample (1,385 cases and 12,569 controls). Multi-ancestry PRSs with weights tuned in European- and African-ancestry samples, respectively, outperformed ancestry-specific PRSs in European- (PRSCSXEUR: AUC=0.61 (0.60, 0.61), PRSCSX_combinedEUR: AUC=0.61 (0.60, 0.62)) and African-ancestry test samples (PRSCSXAFR: AUC=0.58 (0.57, 0.6), PRSCSX_combined AFR: AUC=0.59 (0.57, 0.60)). The highest fifth percentile of the best-performing PRS was associated with 1.9-fold and 1.68-fold increased risk for VTE among European- and African-ancestry subjects, respectively, relative to those in the middle stratum. These findings suggest that the multi-ancestry PRS may be used to identify individuals at highest risk for VTE and provide guidance for the most effective treatment strategy across diverse populations.

Validation of Echocardiographic Measurements in Patients with Pulmonary Embolism in the RIETE Registry

Background  In acute pulmonary embolism (PE), echocardiographic identification of right ventricular (RV) dysfunction will inform prognostication and clinical decision-making. Registro Informatizado Enfermedad TromboEmbolica (RIETE) is the world's largest registry of patients with objectively confirmed PE. The reliability of site-reported RV echocardiographic measurements is unknown. We aimed to validate site-reported key RV echocardiographic measurements in the RIETE registry. Methods  Fifty-one randomly chosen patients in RIETE who had transthoracic echocardiogram (TTE) performed for acute PE were included. TTEs were de-identified and analyzed by a core laboratory of two independent observers blinded to site-reported data. To investigate reliability, intraclass correlation coefficients (ICCs) and Bland-Altman plots between the two observers, and between an average of the two observers and the RIETE site-reported data were obtained. Results  Core laboratory interobserver variations were very limited with correlation coefficients >0.8 for all TTE parameters. Agreement was substantial between core laboratory observers and site-reported data for key parameters including tricuspid annular plane systolic excursion (ICC 0.728; 95% confidence interval [CI], 0.594-0.862) and pulmonary arterial systolic pressure (ICC 0.726; 95% CI, 0.601-0.852). Agreement on right-to-left ventricular diameter ratio (ICC 0.739; 95% CI, 0.443-1.000) was validated, although missing data limited the precision of the estimates. Bland-Altman plots showed differences close to zero. Conclusion  We showed substantial reliability of key RV site-reported measurements in the RIETE registry. Ascertaining the validity of such data adds confidence and reliability for subsequent investigations.

Life expectancy associated with different ages at diagnosis of type 2 diabetes in high-income countries: 23 million person-years of observation

BACKGROUND

The prevalence of type 2 diabetes is increasing rapidly, particularly among younger age groups. Estimates suggest that people with diabetes die, on average, 6 years earlier than people without diabetes. We aimed to provide reliable estimates of the associations between age at diagnosis of diabetes and all-cause mortality, cause-specific mortality, and reductions in life expectancy.

METHODS

For this observational study, we conducted a combined analysis of individual-participant data from 19 high-income countries using two large-scale data sources: the Emerging Risk Factors Collaboration (96 cohorts, median baseline years 1961-2007, median latest follow-up years 1980-2013) and the UK Biobank (median baseline year 2006, median latest follow-up year 2020). We calculated age-adjusted and sex-adjusted hazard ratios (HRs) for all-cause mortality according to age at diagnosis of diabetes using data from 1 515 718 participants, in whom deaths were recorded during 23·1 million person-years of follow-up. We estimated cumulative survival by applying age-specific HRs to age-specific death rates from 2015 for the USA and the EU.

FINDINGS

For participants with diabetes, we observed a linear dose-response association between earlier age at diagnosis and higher risk of all-cause mortality compared with participants without diabetes. HRs were 2·69 (95% CI 2·43-2·97) when diagnosed at 30-39 years, 2·26 (2·08-2·45) at 40-49 years, 1·84 (1·72-1·97) at 50-59 years, 1·57 (1·47-1·67) at 60-69 years, and 1·39 (1·29-1·51) at 70 years and older. HRs per decade of earlier diagnosis were similar for men and women. Using death rates from the USA, a 50-year-old individual with diabetes died on average 14 years earlier when diagnosed aged 30 years, 10 years earlier when diagnosed aged 40 years, or 6 years earlier when diagnosed aged 50 years than an individual without diabetes. Using EU death rates, the corresponding estimates were 13, 9, or 5 years earlier.

INTERPRETATION

Every decade of earlier diagnosis of diabetes was associated with about 3-4 years of lower life expectancy, highlighting the need to develop and implement interventions that prevent or delay the onset of diabetes and to intensify the treatment of risk factors among young adults diagnosed with diabetes.

FUNDING

British Heart Foundation, Medical Research Council, National Institute for Health and Care Research, and Health Data Research UK.

Right-to-left ventricular ratio is higher in systole than diastole in patients with acute pulmonary embolism

OBJECTIVES

In acute pulmonary embolism (PE), the right ventricle (RV) may dilate compromising left ventricular (LV) size, thereby increasing RV/LV ratio. End-diastolic RV/LV ratio is often used in PE risk stratification, though the cause of death is RV systolic failure. We aimed to confirm our pre-clinical observations of higher RV/LV ratio in systole compared to diastole in human patients with PE.

METHODS

We blinded and independently analyzed echocardiograms from 606 patients with PE, evaluated by a Pulmonary Embolism Response Team. We measured RV/LV ratios in end-systole and end-diastole and fractional area change (FAC). Our primary outcome was a composite of 7-day clinical deterioration, treatment escalation or death. Secondary outcomes were 7-day and 30-day all-cause mortality.

RESULTS

RV/LV ratio was higher in systole compared to diastole (median 1.010 [.812-1.256] vs. .975 [.843-1.149], p < .0001). RV/LV in systole and diastole were correlated (slope = 1.30 [95% CI 1.25-1.35], p < .0001 vs. slope = 1). RV/LV ratios in both systole and diastole were associated with the primary composite outcome but not with all-cause mortality.

CONCLUSION

The RV/LV ratio is higher when measured in systole versus in diastole in patients with acute PE. The two approaches had similar associations with clinical outcomes, that is, it appears reasonable to measure RV/LV ratio in diastole.

Low concordance between CTPA and echocardiography in identification of right ventricular strain in PERT patients with acute pulmonary embolism

PURPOSE

Right ventricular strain (RVS) is used to risk stratify patients with acute pulmonary embolism (PE) and influence treatment decisions. Guidelines suggest that either computed tomography pulmonary angiography (CTPA) or transthoracic echocardiography (TTE) can be used to assess RVS. We sought to determine how often CTPA and TTE yield discordant results and to assess the test characteristics of CTPA compared to TTE.

METHODS

We analyzed data from a single-center registry of PE cases severe enough to warrant activation of the hospital's Pulmonary Embolism Response Team (PERT). We defined RVS as a right ventricular to left ventricular ratio (RV/LV) ≥ 1 or radiologist's interpretation of RVS on CTPA or as the presence of either RV dilation, hypokinesis, or septal bowing on TTE.

RESULTS

We included 554 patients in our analysis, of whom 333 (60%) had concordant RVS findings on CTPA and TTE. Using TTE as the reference standard, CTPA had a sensitivity of 95% (95% CI 92-97%) and a specificity of 4% (95% CI 2-8%) for identifying RVS.

CONCLUSIONS

In a selected population of patients with acute PE for which PERT was activated, CTPA is highly sensitive but not specific for the detection of RVS when compared to TTE.

Calendar month variation in the diagnosis and severity of pulmonary embolism

BACKGROUND

Pulmonary embolism (PE) is the third-leading cause of cardiovascular death in the United States, and several studies suggest PE shows seasonal variation. Variation in monthly PE diagnosis may be due to pathophysiologic factors or confounding/bias. However, severe PE may be less prone to diagnostic bias. To address this gap, we analyzed two registries from 1/2013-12/2018 with the aim of describing temporal trends in PE diagnosis and severity.

METHODS

We performed a retrospective analysis of two existing databases containing: (1) consecutive patients diagnosed with PE in the emergency departments (EDs) of two large, urban teaching hospitals, and (2) severe PEs requiring PE Response Team (PERT) activation at one of the above hospitals. The primary outcome was to assess variation in PE diagnosis and severity by calendar month. Separate analysis of these two databases sought to control for workup bias by trainee experience across the academic year. One-way ANOVA and Poisson regression were performed to assess for cyclical variation across calendar months, using Stata v16.1.

RESULTS

The PE diagnosis database contained 1324 patients over 36 months. One-way ANOVA did not reveal a statistically significant (p = 0.713) association between calendar month and PE number. The PERT activation database contained 1082 patients over 72 months. One-way ANOVA revealed a statistically significant (p = 0.024) association between calendar month and activations, repeated year-on-year.

CONCLUSION

Our results indicate correlation between calendar month and PERT activation; however, this pattern was not observed for PE diagnoses. This finding warrants further investigation into the causes of calendar month variation of PERT activations.

Barriers and facilitators to interhospital transfer of acute pulmonary embolism: An inductive qualitative analysis

Background

Interhospital transfer (IHT) of patients with acute life-threatening pulmonary embolism (PE) is necessary to facilitate specialized care and access to advanced therapies. Our goal was to understand what barriers and facilitators may exist during this transfer process from the perspective of both receiving and referring physicians.

Methods

This qualitative descriptive study explored physician experience taking care of patients with life threatening PE. Subject matter expert physicians across several different specialties from academic and community United States hospitals participated in qualitative semi-structured interviews. Interview transcripts were subsequently analyzed using inductive qualitative description approach.

Results

Four major themes were identified as barriers that impede IHT among patients with life threatening PE. Inefficient communication which mainly pertained to difficulty when multiple points of contact were required to complete a transfer. Subjectivity in the indication for transfer which highlighted the importance of physicians understanding how to use standardized risk stratification tools and to properly triage these patients. Delays in data acquisition were identified in regards to both obtaining clinical information and imaging in a timely fashion. Operation barriers which included difficulty finding available beds for transfer and poor weather conditions inhibiting transportation. In contrast, two main facilitators to transfer were identified: good communication and reliance on colleagues and dedicated team for transferring and treating PE patients.

Conclusion

The most prominent themes identified as barriers to IHT for patients with acute life-threatening PE were: (1) inefficient communication, (2) subjectivity in the indication for transfer, (3) delays in data acquisition (imaging or clinical), and (4) operational barriers. Themes identified as facilitators that enable the transfer of patients were: (1) good communication and (2) a dedicated transfer team. The themes presented in our study are useful in identifying opportunities to optimize the IHT of patients with acute PE and improve patient care. These opportunities include instituting educational programs, streamlining the transfer process, and formulating a consensus statement to serve as a guideline regarding IHT of patients with acute PE.

Cross-Ancestry Investigation of Venous Thromboembolism Genomic Predictors

BACKGROUND

Venous thromboembolism (VTE) is a life-threatening vascular event with environmental and genetic determinants. Recent VTE genome-wide association studies (GWAS) meta-analyses involved nearly 30 000 VTE cases and identified up to 40 genetic loci associated with VTE risk, including loci not previously suspected to play a role in hemostasis. The aim of our research was to expand discovery of new genetic loci associated with VTE by using cross-ancestry genomic resources.

METHODS

We present new cross-ancestry meta-analyzed GWAS results involving up to 81 669 VTE cases from 30 studies, with replication of novel loci in independent populations and loci characterization through in silico genomic interrogations.

RESULTS

In our genetic discovery effort that included 55 330 participants with VTE (47 822 European, 6320 African, and 1188 Hispanic ancestry), we identified 48 novel associations, of which 34 were replicated after correction for multiple testing. In our combined discovery-replication analysis (81 669 VTE participants) and ancestry-stratified meta-analyses (European, African, and Hispanic), we identified another 44 novel associations, which are new candidate VTE-associated loci requiring replication. In total, across all GWAS meta-analyses, we identified 135 independent genomic loci significantly associated with VTE risk. A genetic risk score of the significantly associated loci in Europeans identified a 6-fold increase in risk for those in the top 1% of scores compared with those with average scores. We also identified 31 novel transcript associations in transcriptome-wide association studies and 8 novel candidate genes with protein quantitative-trait locus Mendelian randomization analyses. In silico interrogations of hemostasis and hematology traits and a large phenome-wide association analysis of the 135 GWAS loci provided insights to biological pathways contributing to VTE, with some loci contributing to VTE through well-characterized coagulation pathways and others providing new data on the role of hematology traits, particularly platelet function. Many of the replicated loci are outside of known or currently hypothesized pathways to thrombosis.

CONCLUSIONS

Our cross-ancestry GWAS meta-analyses identified new loci associated with VTE. These findings highlight new pathways to thrombosis and provide novel molecules that may be useful in the development of improved antithrombosis treatments.

SARS-CoV-2 Positivity in Ambulatory Symptomatic Patients Is Not Associated With Increased Venous or Arterial Thrombotic Events in the Subsequent 30 Days

BACKGROUND

COVID-19 has been associated with increased risk of thromboembolism in critically ill patients.

OBJECTIVE

We sought to examine the association of SARS-CoV-2 test positivity and subsequent acute vascular thrombosis, including venous thromboembolism (VTE) or arterial thrombosis (AT), in a large nationwide registry of emergency department (ED) patients tested with a nucleic acid test for suspected SARS-CoV-2.

METHODS

The RECOVER (Registry of Potential COVID-19 in Emergency Care) registry includes 155 EDs across the United States. We performed a retrospective cohort study to produce odds ratios (ORs) for COVID-19-positive vs. COVID-19-negative status as a predictor of 30-day VTE or AT, adjusting for age, sex, active cancer, intubation, hospital length of stay, and intensive care unit (ICU) care.

RESULTS

Comparing 14,056 COVID-19-positive patients with 12,995 COVID-19-negative patients, the overall 30-day prevalence of VTE events was 1.4% vs. 1.3%, respectively (p = 0.44, χ²). Multivariable analysis identified that testing positive for SARS-CoV-2 status was negatively associated with both VTE (OR 0.76; 95% confidence interval [CI] 0.61-0.94) and AT (OR 0.51; 95% CI 0.32-0.80), whereas intubation, ICU care, and age 50 years or older were positively associated with both VTE and AT.

CONCLUSIONS

In contrast to other reports, results from this large, hetereogenous national sample of ED patients tested for SARS-CoV-2, showed no association between vascular thrombosis and COVID-19 test positivity.

Disease consequences of higher adiposity uncoupled from its adverse metabolic effects using Mendelian randomisation

Background

Some individuals living with obesity may be relatively metabolically healthy, whilst others suffer from multiple conditions that may be linked to adverse metabolic effects or other factors. The extent to which the adverse metabolic component of obesity contributes to disease compared to the non-metabolic components is often uncertain. We aimed to use Mendelian randomisation (MR) and specific genetic variants to separately test the causal roles of higher adiposity with and without its adverse metabolic effects on diseases.

Methods

We selected 37 chronic diseases associated with obesity and genetic variants associated with different aspects of excess weight. These genetic variants included those associated with metabolically 'favourable adiposity' (FA) and 'unfavourable adiposity' (UFA) that are both associated with higher adiposity but with opposite effects on metabolic risk. We used these variants and two sample MR to test the effects on the chronic diseases.

Results

MR identified two sets of diseases. First, 11 conditions where the metabolic effect of higher adiposity is the likely primary cause of the disease. Here, MR with the FA and UFA genetics showed opposing effects on risk of disease: coronary artery disease, peripheral artery disease, hypertension, stroke, type 2 diabetes, polycystic ovary syndrome, heart failure, atrial fibrillation, chronic kidney disease, renal cancer, and gout. Second, 9 conditions where the non-metabolic effects of excess weight (e.g. mechanical effect) are likely a cause. Here, MR with the FA genetics, despite leading to lower metabolic risk, and MR with the UFA genetics, both indicated higher disease risk: osteoarthritis, rheumatoid arthritis, osteoporosis, gastro-oesophageal reflux disease, gallstones, adult-onset asthma, psoriasis, deep vein thrombosis, and venous thromboembolism.

Conclusions

Our results assist in understanding the consequences of higher adiposity uncoupled from its adverse metabolic effects, including the risks to individuals with high body mass index who may be relatively metabolically healthy.

Funding

Diabetes UK, UK Medical Research Council, World Cancer Research Fund, National Cancer Institute.

Incidence and characteristics of arterial thromboemboli in patients with COVID-19

BACKGROUND

Studies have reported COVID-19 as an independent risk factor for arterial thromboemboli.

METHODS

From a cross-sectional sample, we determined the incidence and location of arterial thromboemboli (myocardial infarction, ischemic stroke, peripheral artery), stratified by COVID-19 status, in the RECOVER database, which included data on patients at 45 United States medical centers in 22 states. Epidemiological factors, clinical characteristics and outcomes were collected through a combination of individual chart review and automatic electronic query and recorded in REDCap®. We investigated the association of baseline comorbidities on the development of arterial thromboemboli and analyzed results based on the presence or absence of concomitant COVID-19 infection, testing this association with Chi-squared. We also described use of anticoagulants and statins.

RESULTS

Data were collected on 26,974 patients, of which 13,803 (51.17%) tested positive for COVID-19. Incidence of arterial thromboemboli during hospitalization was 0.13% in patients who tested positive for COVID-19 and 0.19% in patients who tested negative. Arterial thromboemboli tended to be more common in extremities than in core organs (heart, kidney, lung, liver) in patients with COVID-19, odds ratio 2.04 (95% CI 0.707 - 5.85). Patients with COVID-19 were less likely to develop an arterial thrombus when on baseline statin medication (p=0.014). Presence of metabolic syndrome predicted presence of core arterial thrombus (p=0.001) and extremity arterial thrombus (p=0.010) in those with COVID-19. Arterial thromboemboli were less common in patients with COVID-19 than in those who tested negative for COVID-19.

CONCLUSIONS

Presence of a composite metabolic syndrome profile may be associated with arterial clot formation in patients with COVID-19 infection.

Association between baseline use of angiotensin converting enzyme inhibitors and angiotensin receptor blockers and death among patients tested for COVID-19

Angiotensin converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) drugs may modify risk associated with SARS-CoV-2. Therefore, we assessed whether baseline therapy with ACEI or ARB (ACEI/ARB) was associated with lower mortality, respiratory failure (non-invasive ventilation or intubation) and renal failure (new renal replacement therapy) in SARS-CoV-2-positive patients. This retrospective registry-based observational cohort study used data from a national database of Emergency Department (ED) patients tested for SARS-CoV-2. Symptomatic ED patients were accrued from January-October 2020, across 197 hospitals in the USA. Multivariable analysis using logistic regression evaluated endpoints among SARS-CoV-2-positive cases, focusing on ACEI/ARB and adjusting for covariates. Model performance was evaluated using the c statistic for discrimination, and Cox plotting for calibration. 13,859 (99.9%) patients had known mortality status, of whom 2,045 (14.8%) died. Respiratory failure occurred in 2,485/13,880 (17.9%) and renal failure in 548/13,813 (4.0%) patients with available data. ACEI/ARB status was associated with a 25% decrease in mortality odds (OR 0.75, 95% CI 0.59-0.94, p = .011, c = .82). ACEI/ARB was not significantly associated with respiratory failure (OR 0.89, 95% CI 0.78-1.06, p = .206) or renal failure (OR 0.75, 95% CI 0.55-1.04, p = .083). Adjusting for covariates, baseline ACEI/ARB was associated with 25% lower mortality in SARS-CoV-2-positive patients. The potential mechanism for ACEI/ARB mortality modification requires further exploration. This article is protected by copyright. All rights reserved.

Predicting 30-day return hospital admissions in patients with COVID-19 discharged from the emergency department: A national retrospective cohort study

OBJECTIVES

Identification of patients with coronavirus disease 2019 (COVID-19) at risk for deterioration after discharge from the emergency department (ED) remains a clinical challenge. Our objective was to develop a prediction model that identifies patients with COVID-19 at risk for return and hospital admission within 30 days of ED discharge.

METHODS

We performed a retrospective cohort study of discharged adult ED patients (n = 7529) with SARS-CoV-2 infection from 116 unique hospitals contributing to the National Registry of Suspected COVID-19 in Emergency Care. The primary outcome was return hospital admission within 30 days. Models were developed using classification and regression tree (CART), gradient boosted machine (GBM), random forest (RF), and least absolute shrinkage and selection (LASSO) approaches.

RESULTS

Among patients with COVID-19 discharged from the ED on their index encounter, 571 (7.6%) returned for hospital admission within 30 days. The machine-learning (ML) models (GBM, RF, and LASSO) performed similarly. The RF model yielded a test area under the receiver operating characteristic curve of 0.74 (95% confidence interval [CI], 0.71-0.78), with a sensitivity of 0.46 (95% CI, 0.39-0.54) and a specificity of 0.84 (95% CI, 0.82-0.85). Predictive variables, including lowest oxygen saturation, temperature, or history of hypertension, diabetes, hyperlipidemia, or obesity, were common to all ML models.

CONCLUSIONS

A predictive model identifying adult ED patients with COVID-19 at risk for return for return hospital admission within 30 days is feasible. Ensemble/boot-strapped classification methods (eg, GBM, RF, and LASSO) outperform the single-tree CART method. Future efforts may focus on the application of ML models in the hospital setting to optimize the allocation of follow-up resources.

A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel

The outpatient treatment of select emergency department patients with acute pulmonary embolism (PE) or deep vein thrombosis (DVT) has been shown to be safe, cost effective and associated with high patient satisfaction. Despite this, outpatient PE and DVT treatment remains uncommon. To address this, the American College of Emergency Physicians assembled a multidisciplinary team of content experts to provide evidence-based recommendations and practical advice to help clinicians safely treat patients with low-risk PE and DVT without hospitalization. The emergency clinician must stratify the patient's risk of clinical decompensation due to their PE or DVT as well as their risk of bleeding due to anticoagulation. The clinician must also select and start an anticoagulant and ensure that the patient has access to the medication in a timely manner. Reliable follow-up is critical, and the patient must also be educated about signs or symptoms that should prompt a return to the emergency department. To facilitate access to these recommendations, the consensus panel also created 2 web-based "point-of-care tools."

Predicting factors for pulmonary embolism response team activation in a general pulmonary embolism population

Pulmonary embolism response teams (PERT) aim to improve treatment of acute pulmonary embolism (PE). PERT focus on intermediate- and high-risk PE patients, but recent multicenter studies show that low-risk PE patients compose one in five of all PERT cases. Conversely, not all intermediate- and high-risk PE patients elicit a PERT activation. The factors leading to PERT activations remain unknown. This study aims to describe the patient characteristics associated with PERT activation for low-risk PE patients and characteristics precluding PERT activation for intermediate/high-risk PE patients. We analysed data from all patients with confirmed PE diagnosed in the Massachusetts General Hospital Emergency Department from August 2013 to February 2017 and cross-referred these data with patients who received a PERT activation and patients who did not. Patients were stratified into low-risk or intermediate/high-risk PE. Univariate analyses were performed within each risk group comparing patients with a PERT activation and patients without. Fifteen percent (56/374) of low-risk PE patients triggered a PERT activation. Patient characteristics associated with PERT activation were: (1) vascular disease, (2) pulmonary diseases, (3) thrombophilia, (4) current use of anticoagulants, (5) central PE and (6) concurrent DVT. Thirty-five percent (110/283) of intermediate/high-risk PE patients did not elicit a PERT activation. Patient characteristics precluding a PERT activation were: (1) vascular disease, (2) malignancies and (3) asymptomatic presentation. Low-risk PE patients with PERT activations had more extensive clot burden, complex comorbidities, or had failed anticoagulation treatment. Intermediate/high-risk PE patients without PERT activations tended to have malignancies or vascular disease.

The echocardiographic ratio tricuspid annular plane systolic excursion/pulmonary arterial systolic pressure predicts short-term adverse outcomes in acute pulmonary embolism

AIMS

Right ventricular (RV) failure causes death from acute pulmonary embolism (PE), due to a mismatch between RV systolic function and increased RV afterload. We hypothesized that an echocardiographic ratio of this mismatch [RV systolic function by tricuspid annular plane systolic excursion (TAPSE) divided by pulmonary arterial systolic pressure (PASP)] would predict adverse outcomes better than each measurement individually, and would be useful for risk stratification in intermediate-risk PE.

METHODS AND RESULTS

This was a retrospective analysis of a single academic centre Pulmonary Embolism Response Team registry from 2012 to 2019. All patients with confirmed PE and a formal transthoracic echocardiogram performed within 2 days were included. All echocardiograms were analysed by an observer blinded to the outcome. The primary endpoint was a 7-day composite outcome of death or haemodynamic deterioration. Secondary outcomes were 7- and 30-day all-cause mortality. A total of 627 patients were included; 135 met the primary composite outcome. In univariate analysis, the TAPSE/PASP was associated with our primary outcome [odds ratio = 0.028, 95% confidence interval (CI) 0.010-0.087; P < 0.0001], which was significantly better than either TAPSE or PASP alone (P = 0.017 and P < 0.0001, respectively). A TAPSE/PASP cut-off value of 0.4 was identified as the optimal value for predicting adverse outcome in PE. TAPSE/PASP predicted both 7- and 30-day all-cause mortality, while TAPSE and PASP did not.

CONCLUSION

A combined echocardiographic ratio of RV function to afterload is superior in prediction of adverse outcome in acute intermediate-risk PE. This ratio may improve risk stratification and identification of the patients that will suffer short-term deterioration after intermediate-risk PE.

Sex-related differences in D-dimer levels for venous thromboembolism screening

BACKGROUND

D-dimer is generally considered positive above 0.5 mg/L irrespective of sex. However, women have been shown to be more likely to have a positive D-dimer after controlling for other factors. Thus, differences may exist between males and females for using D-dimer as a marker of venous thromboembolic (VTE) disease. We hypothesized that the accuracy of D-dimer tests may be enhanced by using appropriate cutoff values that reflect sex-related differences in D-dimer levels.

METHODS

This research is a secondary analysis of a multicenter, international, prospective, observational study of adult (18+ years) patients suspected of VTE, with low-to-intermediate pretest probability based on Wells criteria ≤ 6 for pulmonary embolism (PE) and ≤ 2 for deep vein thrombosis (DVT). VTE diagnoses were based on computed tomography, ventilation perfusion scanning, or venous ultrasound. D-dimer levels were tested for statistical difference across groups stratified by sex and diagnosis. Multivariable regression was used to investigate sex as a predictor of diagnosis. Sex-specific optimal D-dimer thresholds for PE and DVT were calculated from receiver operating characteristic analyses. A Youden threshold (D-dimer level coinciding with the maximum of sensitivity plus specificity) and a cutoff corresponding to 95% sensitivity were calculated. Statistical difference for cutoffs was tested via 95% confidence intervals from 2,000 bootstrapped samples.

RESULTS

We included 3,586 subjects for analysis, of whom 61% were female. Race demographics were 63% White, 27% Black/African American, and 6% Hispanic. In the suspected PE cohort, 6% were diagnosed with PE, while in the suspected DVT cohort, 11% were diagnosed with DVT. D-dimer levels were significantly higher in males than females for the PE-positive group and the DVT-negative group, but males had significantly lower D-dimer levels than females in the PE-negative group. Regression models showed male sex as a significant positive predictor of DVT diagnosis, controlling for D-dimer levels. The Youden thresholds for PE patients were 0.97 (95% CI = 0.64 to 1.79) mg/L and 1.45 (95% CI = 1.36 to 1.95) mg/L for females and males, respectively; 95% sensitivity cutoffs for this group were 0.64 (95% CI = 0.20 to 0.89) and 0.55 (95% CI = 0.29 to 1.61). For DVT, the Youden thresholds were 0.98 (95% CI = 0.84 to 1.56) mg/L for females and 1.25 (95% CI = 0.65 to 3.33) mg/L for males with 95% sensitivity cutoffs of 0.33 (95% CI = 0.2 to 0.61) and 0.32 (95% CI = 0.18 to 0.7), respectively.

CONCLUSION

Differences in D-dimer levels between males and females are diagnosis specific; however, there was no significant difference in optimal cutoff values for excluding PE and DVT between the sexes.

Interhospital Transfer of Patients With Acute Pulmonary Embolism (PE): Challenges and Opportunities

Acute pulmonary embolism (PE) is associated with significant morbidity and mortality. The management paradigm for acute PE has evolved in recent years with wider availability of advanced treatment modalities ranging from catheter-directed reperfusion therapies to mechanical circulatory support. This evolution has coincided with the development and implementation of institutional pulmonary embolism response teams (PERT) nationwide and internationally. Because most institutions are not equipped or staffed for advanced PE care, patients often require transfer to centers with more comprehensive resources, including PERT expertise. One of the unmet needs in current PE care is an organized approach to the process of interhospital transfer (IHT) of critically ill PE patients. In this review, we discuss medical optimization and support of patients before and during transfer, transfer checklists, defined roles of emergency medical services, and the roles and responsibilities of referring and receiving centers involved in the IHT of acute PE patients.

Clinical prediction rule for SARS-CoV-2 infection from 116 U.S. emergency departments 2-22-2021

Objectives

Accurate and reliable criteria to rapidly estimate the probability of infection with the novel coronavirus-2 that causes the severe acute respiratory syndrome (SARS-CoV-2) and associated disease (COVID-19) remain an urgent unmet need, especially in emergency care. The objective was to derive and validate a clinical prediction score for SARS-CoV-2 infection that uses simple criteria widely available at the point of care.

Methods

Data came from the registry data from the national REgistry of suspected COVID-19 in EmeRgency care (RECOVER network) comprising 116 hospitals from 25 states in the US. Clinical variables and 30-day outcomes were abstracted from medical records of 19,850 emergency department (ED) patients tested for SARS-CoV-2. The criterion standard for diagnosis of SARS-CoV-2 required a positive molecular test from a swabbed sample or positive antibody testing within 30 days. The prediction score was derived from a 50% random sample (n = 9,925) using unadjusted analysis of 107 candidate variables as a screening step, followed by stepwise forward logistic regression on 72 variables.

Results

Multivariable regression yielded a 13-variable score, which was simplified to a 13-point score: +1 point each for age>50 years, measured temperature>37.5°C, oxygen saturation<95%, Black race, Hispanic or Latino ethnicity, household contact with known or suspected COVID-19, patient reported history of dry cough, anosmia/dysgeusia, myalgias or fever; and -1 point each for White race, no direct contact with infected person, or smoking. In the validation sample (n = 9,975), the probability from logistic regression score produced an area under the receiver operating characteristic curve of 0.80 (95% CI: 0.79–0.81), and this level of accuracy was retained across patients enrolled from the early spring to summer of 2020. In the simplified score, a score of zero produced a sensitivity of 95.6% (94.8–96.3%), specificity of 20.0% (19.0–21.0%), negative likelihood ratio of 0.22 (0.19–0.26). Increasing points on the simplified score predicted higher probability of infection (e.g., >75% probability with +5 or more points).

Conclusion

Criteria that are available at the point of care can accurately predict the probability of SARS-CoV-2 infection. These criteria could assist with decisions about isolation and testing at high throughput checkpoints.

Qualitative and quantitative DECT pulmonary angiography in COVID-19 pneumonia and pulmonary embolism

AIM

To assess differences in qualitative and quantitative parameters of pulmonary perfusion from dual-energy computed tomography (CT) pulmonary angiography (DECT-PA) in patients with COVID-19 pneumonia with and without pulmonary embolism (PE).

MATERIALS AND METHODS

This retrospective institutional review board-approved study included 74 patients (mean age 61±18 years, male:female 34:40) with COVID-19 pneumonia in two countries (one with 68 patients, and the other with six patients) who underwent DECT-PA on either dual-source (DS) or single-source (SS) multidetector CT machines. Images from DS-DECT-PA were processed to obtain virtual mono-energetic 40 keV (Mono40), material decomposition iodine (MDI) images and quantitative perfusion statistics (QPS). Two thoracic radiologists determined CT severity scores based on type and extent of pulmonary opacities, assessed presence of PE, and pulmonary parenchymal perfusion on MDI images. The QPS were calculated from the CT Lung Isolation prototype (Siemens). The correlated clinical outcomes included duration of hospital stay, intubation, SpO₂ and death. The significance of association was determined by receiver operating characteristics and analysis of variance.

RESULTS

One-fifth (20.2%, 15/74 patients) had pulmonary arterial filling defects; most filling defects were occlusive (28/44) located in the segmental and sub-segmental arteries. The parenchymal opacities were more extensive and denser (CT severity score 24±4) in patients with arterial filling defects than without filling defects (20±8; p=0.028). Ground-glass opacities demonstrated increased iodine distribution; mixed and consolidative opacities had reduced iodine on DS-DECT-PA but increased or heterogeneous iodine content on SS-DECT-PA. QPS were significantly lower in patients with low SpO₂ (p=0.003), intubation (p=0.006), and pulmonary arterial filling defects (p=0.007).

CONCLUSION

DECT-PA QPS correlated with clinical outcomes in COVID-19 patients.

Patient and operational factors that influence the decision to place an inferior vena cava filter in a pulmonary embolism response team

OBJECTIVE

The use of inferior vena cava (IVC) filters is controversial. However, the procedure is widely performed for secondary prophylaxis in patients with severe pulmonary embolism (PE), including those treated by a PE response team (PERT). In this study, we analyzed patient factors associated with the clinical decision to place an IVC filter in PERT patients.

METHODS

Data were collected on all Massachusetts General Hospital patients who had a PERT activation from October 1, 2012, to January 29, 2019. Data describing demographics, medical history, PE characteristics and treatment were collected at the time of PERT activation and prospectively for one year after PERT activation. Univariate and multivariable regression analyses were performed to determine factors associated with IVC filter placement.

RESULTS

We identified 834 patients, of whom 91 (10.9%) had an IVC filter placed in the first 7 days after PERT activation. The majority of patients receiving an IVC filter were male (55/91 [60.4%]; P =.096) with a mean age of 65 ± 15.0 years. Patients who received an IVC filter were less likely to have had a PERT referral from the Emergency Department (ED) (41/544 [7.5%]; P < .001) and more likely to have been referred from the intensive care unit (24/107 [22.43%]; P ≤ .001) compared with a floor referral. Patients who presented with syncope (15/86 [17.4%]; P = .040), a history of recent trauma (12/41 [29.3%]; P < .001), intracranial hemorrhage (11/39 [28.2%]; P = .002), a recent surgery or invasive procedure (30/188 [16.0%]; P = .012), a recent surgery (29/160 [18.1%]; P = .001) and a recent hospitalization (38/250 [15.2%]; P = .009) were more likely to have an IVC filter placed. Patients receiving an IVC filter were also more likely to have evidence of right heart dysfunction on a computed tomography pulmonary angiogram (61/359 [17.0%]; P < .001) and an echocardiogram (26/144 [18.1%]; P = .003). Compared with patients without an IVC filter, the 30-day venous thromboembolism recurrence rate was higher (4.7% vs 11.0%) in patients with IVC filters (10/45 [22.2%]; P = .023).

CONCLUSIONS

Factors associated with venous thromboembolism severity (eg, PERT referral from intensive care unit and right ventricular dysfunction) and an increased bleeding risk (eg, recent surgery or trauma) were associated with IVC filter placement among PERT patients.

Diagnosis and Treatment of Pulmonary Embolism During the Coronavirus Disease 2019 Pandemic: A Position Paper From the National PERT Consortium

The coexistence of coronavirus disease 2019 (COVID-19) and pulmonary embolism (PE), two life-threatening illnesses, in the same patient presents a unique challenge. Guidelines have delineated how best to diagnose and manage patients with PE. However, the unique aspects of COVID-19 confound both the diagnosis and treatment of PE, and therefore require modification of established algorithms. Important considerations include adjustment of diagnostic modalities, incorporation of the prothrombotic contribution of COVID-19, management of two critical cardiorespiratory illnesses in the same patient, and protecting patients and health-care workers while providing optimal care. The benefits of a team-based approach for decision-making and coordination of care, such as that offered by pulmonary embolism response teams (PERTs), have become more evident in this crisis. The importance of careful follow-up care also is underscored for patients with these two diseases with long-term effects. This position paper from the PERT Consortium specifically addresses issues related to the diagnosis and management of PE in patients with COVID-19.

Multicenter registry of United States emergency department patients tested for SARS-CoV-2

This paper summarizes the methodology for the registry of suspected COVID-19 in emergency care (RECOVER), a large clinical registry of patients from 155 United States (US) emergency departments (EDs) in 27 states tested for SARS-CoV-2 from March-September 2020. The initial goals are to derive and test: (1) a pretest probability instrument for prediction of SARS-CoV-2 test results, and from this instrument, a set of simple criteria to exclude COVID-19 (the COVID-19 Rule-Out Criteria-the CORC rule), and (2) a prognostic instrument for those with COVID-19. Patient eligibility included any ED patient tested for SARS-CoV-2 with a nasal or oropharyngeal swab. Abstracted clinical data included 204 variables representing the earliest manifestation of infection, including week of testing, demographics, symptoms, exposure risk, past medical history, test results, admission status, and outcomes 30 days later. In addition to the primary goals, the registry will provide a vital platform for characterizing the course, epidemiology, clinical features, and prognosis of patients tested for COVID-19 in the ED setting.

Left Ventricular Dysfunction Correlates With Mortality in Pulmonary Embolism

BACKGROUND

Risk stratification of patients with pulmonary embolism (PE) is essential to guide advanced interventional management and proper disposition.

OBJECTIVES

In this study, we sought to assess individual echocardiographic markers of right ventricular (RV) strain and left ventricular (LV) function in patients with high-risk PE and identify their association with the need for advanced intervention (such as thrombolysis) and 30-day mortality.

METHODS

This was a retrospective study of ED patients with PE who were subject to a pulmonary embolism response team activation over a 5-year period. Cardiac point-of-care ultrasound studies were performed as part of patient care and later assessed for septal bowing, RV hypokinesis, McConnell sign, RV enlargement, tricuspid annular place systolic excursion, and LV systolic dysfunction. Outcome variables included need for advanced intervention and 30-day mortality.

RESULTS

The pulmonary embolism response team was activated in 893 patients, of which 718 had a confirmed PE. Of these, 90 had adequate cardiac point-of-care ultrasound images available for review. Patients who needed an advanced intervention were more likely to have septal bowing (odds ratio [OR] 8.69, 95% confidence interval [CI] 2.37-31.86), RV enlargement (OR 4.02, 95% CI 1.43-11.34), and a McConnell sign (OR 2.79, 95% CI 1.09-7.13). LV dysfunction was the only statistically significant predictor of 30-day mortality (OR 9.63, 95% CI 1.74-53.32).

CONCLUSION

In patients with PE in the ED, sonographic findings of RV strain that are more commonly associated with advanced intervention included septal bowing, McConnell sign, and RV enlargement. LV dysfunction was associated with a higher 30-day mortality. These findings can help inform decisions about ED management and disposition of patients with PE.

Abdominal pain in a patient with COVID-19 infection: A case of multiple thromboemboli

The novel coronavirus SARS-CoV-2 (COVID-19) pandemic has created diagnostic uncertainty with regards to distinguishing this infection from pulmonary embolism (PE). Although there appears to be an increased incidence of thromboembolic disease in patients with COVID-19 infection, recommendations regarding anticoagulation are lacking. We present the case of a 61-year-old woman with clinically significant venous and arterial thromboemboli in the setting of COVID-19 infection requiring tissue plasminogen activator (tPA).

Current Controversies in Caring for the Critically Ill Pulmonary Embolism Patient

Emergency physicians must be prepared to rapidly diagnose and resuscitate patients with pulmonary embolism (PE). Certain aspects of PE resuscitation run counter to typical approaches. A specific understanding of the pathophysiology of PE is required to avoid cardiovascular collapse potentially associated with excessive intravenous fluids and positive pressure ventilation. Once PE is diagnosed, rapid risk stratification should be performed and treatment guided by patient risk class. Although anticoagulation remains the mainstay of PE treatment, emergency physicians also must understand the indications and contraindications for thrombolysis and should be aware of new therapies and models of care that may improve outcomes.

Comparison of 4 Acute Pulmonary Embolism Mortality Risk Scores in Patients Evaluated by Pulmonary Embolism Response Teams

IMPORTANCE

The risk of death from acute pulmonary embolism can range as high as 15%, depending on patient factors at initial presentation. Acute treatment decisions are largely based on an estimate of this mortality risk.

OBJECTIVE

To assess the performance of risk assessment scores in a modern, US cohort of patients with acute pulmonary embolism.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study was conducted between October 2016 and October 2017 at 8 hospitals participating in the Pulmonary Embolism Response Team (PERT) Consortium registry. Included patients were adults who presented with acute pulmonary embolism and had sufficient information in the medical record to calculate risk scores. Data analysis was performed from March to May 2020.

MAIN OUTCOMES AND MEASURES

All-cause mortality (7- and 30-day) and associated discrimination were assessed by the area under the receiver operator curve (AUC).

RESULTS

Among 416 patients with acute pulmonary embolism (mean [SD] age, 61.3 [17.6] years; 207 men [49.8%]), 7-day mortality in the low-risk groups ranged from 1.3% (1 patient) to 3.1% (4 patients), whereas 30-day mortality ranged from 2.6% (1 patient) to 10.2% (13 patients). Among patients in the highest-risk groups, the 7-day mortality ranged from 7.0% (18 patients) to 16.3% (7 patients), whereas 30-day mortality ranged from 14.4% (37 patients) to 26.3% (26 patients). Each of the risk stratification tools had modest discrimination for 7-day mortality (AUC range, 0.616-0.666) with slightly lower discrimination for 30-day mortality (AUC range, 0.550-0.694).

CONCLUSIONS AND RELEVANCE

These findings suggest that commonly used risk tools for acute pulmonary embolism have modest estimating ability. Future studies to develop and validate better risk assessment tools are needed.

Special Considerations in Pulmonary Embolism: Clot-in-Transit and Incidental Pulmonary Embolism

This article describes 2 relatively rare, but complex situations in pulmonary embolism (PE): clot-in-transit (CIT), incidental PE (IPE). CIT describes a venous thromboembolism that has become lodged in the right heart. CIT is associated with high mortality and presents unique challenges in management. Incidental PE (IPE) describes PE diagnosed on imaging performed for another indication. The treatment is complex because there is often a disconnect between the PE severity on imaging and lack of severity of the clinical presentation. We summarize the available literature and aid clinicians as they manage patients with PE across the clinical severity spectrum.

Percutaneous Thrombectomy in Emergency Department Patients with Pulmonary Embolism: The FLARE ED Sub-study

BACKGROUND

The FlowTriever Pulmonary Embolectomy Clinical Study (FLARE) was a multicenter, single-arm trial that demonstrated effectiveness of the FlowTriever percutaneous pulmonary embolectomy system in reducing right ventricular/left ventricular (RV/LV) diameter ratio in patients with acute intermediate-risk pulmonary embolism (PE). Patients diagnosed in emergency departments (EDs) with acute PE may have a different presentation from those diagnosed in an in-hospital setting.

OBJECTIVES

The goal of this sub-study was to evaluate the safety and effectiveness of mechanical embolectomy in ED patients with acute intermediate-risk PE.

METHODS

ED patients with acute PE and RV/LV ratio ≥ 0.9 enrolled in the FLARE study were core laboratory analyzed. The primary efficacy endpoint was the change in RV/LV ratio from baseline to 48 h post procedure. The change in RV/LV ratio of patients with nonelevated cardiac troponin (cTn) and zero simplified PE Severity Index (sPESI) score (normal cTn-sPESI: intermediate-low risk) was also examined. Major adverse events (MAEs) included major bleeding, device-related death or clinical deterioration, and vascular or cardiac injury.

RESULTS

Seventy-six ED patients were included. Thirty-nine had a sPESI score of ≥ 1 and 32 had elevated cTn. The median preprocedure RV/LV ratio for all ED patients was 1.50 (0.88-2.52), with a change by -0.37 postprocedure (p < 0.001.) Three patients experienced MAEs. Seventeen patients (22.4%) presented with normal cTn-sPESI and had an RV/LV ratio reduced by 0.27 (p < 0.001) after embolectomy.

CONCLUSION

ED patients with intermediate-risk PE had significant improvement in their RV/LV ratio and low complication rates when treated with mechanical embolectomy, irrespective of their baseline cTn-sPESI risk score.

Analysis of Partial Thromboplastin Times in Patients With Pulmonary Embolism During the First 48 Hours of Anticoagulation With Unfractionated Heparin

OBJECTIVE

The objective was to determine the proportion of patients with pulmonary embolism (PE) treated with unfractionated heparin (UFH) who achieved therapeutic activated partial thromboplastin time (aPTT) values within 48 hours of treatment.

METHODS

Retrospective analysis of a PE response team (PERT) database was performed at a large, urban, academic teaching hospital. Inclusion criteria were adult patients with acute PE for whom the PERT was consulted and who received anticoagulation (AC) with UFH according to guideline standard dosing. aPTT values during 6-hour time periods during the first 48 hours of AC were collected and analyzed.

RESULTS

A total of 505 patients met inclusion criteria. For patients receiving a bolus and infusion of UFH, the proportions (95% confidence interval [CI]) of patients in the therapeutic range were 19.0% (14.2% to 25.0%) at 12 hours, 26.3% (26.3% to 33.1%) at 24 hours, 28.3% (22.0% to 35.4%) at 36 hours, and 28.4% (20.8% to 37.5%) at 48 hours. For titrated infusion only, the proportions (95% CIs) of patients were 23.3% (16.2% to 32.3%) at 12 hours, 41.4% (31.6% to 51.9%) at 24 hours, 37.0% (26.8% to 48.5%) at 36 hours, and 42.1% (30.2% to 55.0%) at 48 hours. No patient had all therapeutic aPTT values.

CONCLUSIONS

The majority of patients with acute PE spend most of their first 48 hours outside of the therapeutic range of AC when treated with guideline standard dosing of UFH. Over half of the patients fail to achieve any therapeutic PTT level within 24 hours of UFH initiation, and no patient had all therapeutic aPTTs. Future research should focus on identifying factors associated with achieving therapeutic AC with UFH.

Diagnosis, Treatment and Follow Up of Acute Pulmonary Embolism: Consensus Practice from the PERT Consortium

Pulmonary embolism (PE) is a life-threatening condition and a leading cause of morbidity and mortality. There have been many advances in the field of PE in the last few years, requiring a careful assessment of their impact on patient care. However, variations in recommendations by different clinical guidelines, as well as lack of robust clinical trials, make clinical decisions challenging. The Pulmonary Embolism Response Team Consortium is an international association created to advance the diagnosis, treatment, and outcomes of patients with PE. In this consensus practice document, we provide a comprehensive review of the diagnosis, treatment, and follow-up of acute PE, including both clinical data and consensus opinion to provide guidance for clinicians caring for these patients.

Rare Genetic Variants Associated With Sudden Cardiac Death in Adults

BACKGROUND

Sudden cardiac death occurs in ∼220,000 U.S. adults annually, the majority of whom have no prior symptoms or cardiovascular diagnosis. Rare pathogenic DNA variants in any of 49 genes can pre-dispose to 4 important causes of sudden cardiac death: cardiomyopathy, coronary artery disease, inherited arrhythmia syndrome, and aortopathy or aortic dissection.

OBJECTIVES

This study assessed the prevalence of rare pathogenic variants in sudden cardiac death cases versus controls, and the prevalence and clinical importance of such mutations in an asymptomatic adult population.

METHODS

The authors performed whole-exome sequencing in a case-control cohort of 600 adult-onset sudden cardiac death cases and 600 matched controls from 106,098 participants of 6 prospective cohort studies. Observed DNA sequence variants in any of 49 genes with known association to cardiovascular disease were classified as pathogenic or likely pathogenic by a clinical laboratory geneticist blinded to case status. In an independent population of 4,525 asymptomatic adult participants of a prospective cohort study, the authors performed whole-genome sequencing and determined the prevalence of pathogenic or likely pathogenic variants and prospective association with cardiovascular death.

RESULTS

Among the 1,200 sudden cardiac death cases and controls, the authors identified 5,178 genetic variants and classified 14 as pathogenic or likely pathogenic. These 14 variants were present in 15 individuals, all of whom had experienced sudden cardiac death-corresponding to a pathogenic variant prevalence of 2.5% in cases and 0% in controls (p < 0.0001). Among the 4,525 participants of the prospective cohort study, 41 (0.9%) carried a pathogenic or likely pathogenic variant and these individuals had 3.24-fold higher risk of cardiovascular death over a median follow-up of 14.3 years (p = 0.02).

CONCLUSIONS

Gene sequencing identifies a pathogenic or likely pathogenic variant in a small but potentially important subset of adults experiencing sudden cardiac death; these variants are present in ∼1% of asymptomatic adults.

Genome-wide association analysis of venous thromboembolism identifies new risk loci and genetic overlap with arterial vascular disease

Venous thromboembolism is a significant cause of mortality1, yet its genetic determinants are incompletely defined. We performed a discovery genome-wide association study in the Million Veteran Program and UK Biobank, with testing of approximately 13 million DNA sequence variants for association with venous thromboembolism (26,066 cases and 624,053 controls) and meta-analyzed both studies, followed by independent replication with up to 17,672 venous thromboembolism cases and 167,295 controls. We identified 22 previously unknown loci, bringing the total number of venous thromboembolism-associated loci to 33, and subsequently fine-mapped these associations. We developed a genome-wide polygenic risk score for venous thromboembolism that identifies 5% of the population at an equivalent incident venous thromboembolism risk to carriers of the established factor V Leiden p.R506Q and prothrombin G20210A mutations. Our data provide mechanistic insights into the genetic epidemiology of venous thromboembolism and suggest a greater overlap among venous and arterial cardiovascular disease than previously thought.

Interventional Therapies for Acute Pulmonary Embolism: Current Status and Principles for the Development of Novel Evidence: A Scientific Statement From the American Heart Association

Pulmonary embolism (PE) represents the third leading cause of cardiovascular mortality. The technological landscape for management of acute intermediate- and high-risk PE is rapidly evolving. Two interventional devices using pharmacomechanical means to recanalize the pulmonary arteries have recently been cleared by the US Food and Drug Administration for marketing, and several others are in various stages of development. The purpose of this document is to clarify the current state of endovascular interventional therapy for acute PE and to provide considerations for evidence development for new devices that will define which patients with PE would derive the greatest net benefit from their use in various clinical settings. First, definitions and limitations of commonly used risk stratification tools for PE are reviewed. An adjudication of risks and benefits of available interventional therapies for PE follows. Next, considerations for optimal future evidence development in this field are presented in the context of the current US regulatory framework. Finally, the document concludes with a discussion of the pros and cons of the rapidly expanding PE response team model of care delivery.

Pulmonary embolism response teams: Purpose, evidence for efficacy, and future research directions

Pulmonary embolism (PE) is a major cause of morbidity and mortality in the United States. Although new therapeutic tools and strategies have recently been developed for the diagnosis and treatment of patients with PE, the outcomes for patients who present with massive or high-risk PE remain dismal. To address this crisis, pulmonary embolism response teams (PERTs) are being created around the world in an effort to immediately and simultaneously engage multiple specialists to determine the best course of action and coordinate the clinical care for patients with acute PE. The scope of this review is to describe the PERT model and purpose, present the structure and organization, examine the available evidence for efficacy and usefulness, and propose future directions for research that is needed to demonstrate the value of PERT and determine if this multidisciplinary approach represents a new standard of care.

Multicenter Implementation of a Novel Management Protocol Increases the Outpatient Treatment of Pulmonary Embolism and Deep Vein Thrombosis

OBJECTIVE

The objective was to determine whether a protocol combining risk stratification, treatment with the direct-acting oral anticoagulant rivaroxaban, and defined follow-up is associated with a greater proportion of patients with venous thromboembolism (VTE) treated as outpatients, without hospital admission.

METHODS

We performed a multicenter study of patients diagnosed with VTE (pulmonary embolism [PE] or deep vein thrombosis [DVT]) in two urban EDs, 18 months before and 18 months after implementation of an outpatient VTE treatment protocol. Patients with radiographically confirmed acute VTE were eligible. Our primary outcome was the proportion of VTE patients discharged from the ED or observation unit (i.e., without hospital admission). We performed subgroup analyses according to hospital, DVT and PE, and low-risk PE. We also assessed 7- and 30-day mortality, major bleeding, and returns to the ED. We compared proportions using chi-square and Fisher's exact tests.

RESULTS

We enrolled 2,212 patients, 1,081 (49%) before protocol and 1,131 (51%) after protocol. Mean age (59 years vs. 60 years), female sex (49% vs. 49%), other demographics, comorbid illness, and PE risk stratification were similar before and after. After protocol, more VTE (35% from 26%, p < 0.001), PE (18% from 12%, p = 0.002), low-risk PE (28% from 18%, p < 0.001), and DVT (60% from 49%, p = 0.002) patients were treated as outpatients. Mortality, bleeding, and returns to ED were rare and did not increase after protocol.

CONCLUSIONS

A treatment protocol combining risk-stratification, rivaroxaban treatment and defined follow-up is associated with an increase in PE and DVT patients treated as outpatients, with no increase in adverse outcomes.

A large-scale exome array analysis of venous thromboembolism

Although recent Genome-Wide Association Studies have identified novel associations for common variants, there has been no comprehensive exome-wide search for low-frequency variants that affect the risk of venous thromboembolism (VTE). We conducted a meta-analysis of 11 studies comprising 8,332 cases and 16,087 controls of European ancestry and 382 cases and 1,476 controls of African American ancestry genotyped with the Illumina HumanExome BeadChip. We used the seqMeta package in R to conduct single variant and gene-based rare variant tests. In the single variant analysis, we limited our analysis to the 64,794 variants with at least 40 minor alleles across studies (minor allele frequency [MAF] ~0.08%). We confirmed associations with previously identified VTE loci, including ABO, F5, F11, and FGA. After adjusting for multiple testing, we observed no novel significant findings in single variant or gene-based analysis. Given our sample size, we had greater than 80% power to detect minimum odds ratios greater than 1.5 and 1.8 for a single variant with MAF of 0.01 and 0.005, respectively. Larger studies and sequence data may be needed to identify novel low-frequency and rare variants associated with VTE risk.

Pulmonary Embolism Response Team: Inpatient Structure, Outpatient Follow-up, and Is It the Current Standard of Care?

Pulmonary Embolism Response Teams (PERTs) are being created around the United States to immediately and simultaneously bring together multiple specialists to determine the best course of action and coordinate clinical care for patients with severe pulmonary embolism (PE). The organization and structure of each PERT will depend on local clinical demands and resources. Creating a follow up clinic for PE patients after discharge from the hospital is an essential component of any PERT program. PERT programs, which have come together to form the PERT Consortium®, are changing the landscape of PE treatment and may represent a new standard of care.