Trends in incidence versus case fatality rates of pulmonary embolism: Good news or bad news?

Management of Complications in Neuro-oncology Patients

OBJECTIVE

The purpose of this article is to familiarize the reader with the spectrum of neurologic and medical complications relevant to the care of patients with neurologic cancer while highlighting best practices to prevent morbidity and mortality. Topics include tumor-related epilepsy, vasogenic edema, complications of corticosteroid use, disruption of the hypothalamic-pituitary axis, venous thromboembolism, and opportunistic infection.

LATEST DEVELOPMENTS

In 2021, a joint guideline from the Society for Neuro-Oncology and the European Association of Neuro-Oncology reaffirmed recommendations first established in 2000 that patients with newly diagnosed brain tumors should not be prescribed an antiseizure medication prophylactically. For those with tumor-related epilepsy, monotherapy with a non-enzyme-inducing anticonvulsant is the preferred initial treatment, and levetiracetam remains the preferred first choice. Surveys of physician practice continue to demonstrate excessive use of glucocorticoids in the management of patients with both primary and metastatic central nervous system malignancy. This is particularly concerning among patients who require checkpoint inhibitors as the efficacy of these agents is blunted by concomitant glucocorticoid use, resulting in a reduction in overall survival. Finally, direct oral anticoagulants have been shown to be safe in patients with brain tumors and are now favored as first-line treatment among those who require treatment for venous thromboembolism.

ESSENTIAL POINTS

Medical care for patients impacted by primary and secondary central nervous system malignancy is complex and requires a committed team-based approach that routinely calls upon the expertise of physicians across multiple fields. Neurologists have an important role to play and should be familiar with the spectrum of complications impacting these patients as well as the latest recommendations for management.

To Study the Correlation of Clinical Severity and Cytokine Storm in COVID-19 Pulmonary Embolism Patients by Using Computed Tomography Pulmonary Angiography (CTPA) Qanadli Clot Burden Scoring System

BACKGROUND

Pulmonary embolism (PE) is a fatal form of venous thromboembolism (VTE), with an overall untreated mortality of up to 30%. Greater than 50% of patients with lower extremity proximal DVT have concurrent PE at presentation. VTE has been seen in up to one-third of patients with COVID-19 infections requiring intensive care unit (ICU) admission. The objective of this study is to determine the correlation between CT pulmonary angiography, pulmonary embolism clot burden, and the Qanadli scoring system with clinically severe COVID-19 pneumonia and cytokine storm.

MATERIAL AND METHOD

153 COVID-19 hospitalized patients who underwent CT pulmonary angiography (CTPA) for likely PE on pretest probability modified Wells criteria were enrolled. COVID-19 pneumonia was classified as URTI (upper respiratory tract infection), mild, severe, and critical COVID pneumonia. For data analysis, we categorized into two groups: (1) the non-severe group included URTI and mild pneumonia, and (2) the severe group included severe and critical pneumonia. We used the Qanadli scoring system to assess the PE percentages of pulmonary vascular obstruction using CTPA.  Results: 41.8% (64) of COVID-19 patients were diagnosed with pulmonary embolism (PE) on CTPA. The majority of 51.6% of pulmonary vascular occlusions using the Qanadli scoring system for pulmonary embolism were at segmental arterial levels. Out of 104 COVID-19 cytokine storm patients, 45 (43%) were associated with pulmonary embolism. Overall, a 25% (16) mortality rate was observed in COVID-19 patients with pulmonary embolism.

DISCUSSION

The pathogenesis of hypercoagulability in COVID-19 may include direct endothelial cell invasion by the virus, microvascular inflammation, endothelial exocytosis, and endotheliitis. A meta-analysis of 71 studies to investigate the occurrence of PE on CTPA in COVID-19 patients found 48.6% in ICU settings and 65.3% of patients have clots in the peripheral pulmonary vasculature.

CONCLUSIONS

There is a significant correlation between pulmonary embolism and high clot burden Qanadli CTPA scores, as well as between the severity of COVID-19 pneumonia and mortality. The association between critically ill COVID-19 pneumonia and pulmonary embolism may result in higher mortality and a poor prognostic marker.

The Challenge of Intermediate-Risk Pulmonary Embolism

BACKGROUND

Intermediate-risk pulmonary embolism is a common disease that is associated with significant morbidity and mortality; however, a standardized treatment protocol is not well-established.

AREAS OF UNCERTAINTY

Treatments available for intermediate-risk pulmonary embolisms include anticoagulation, systemic thrombolytics, catheter-directed therapies, surgical embolectomy, and extracorporeal membrane oxygenation. Despite these options, there is no clear consensus on the optimal indication and timing of these interventions.

THERAPEUTIC ADVANCES

Anticoagulation remains the cornerstone of treatment for pulmonary embolism; however, over the past 2 decades, there have been advances in the safety and efficacy of catheter-directed therapies. For massive pulmonary embolism, systemic thrombolytics and, sometimes, surgical thrombectomy are considered first-line treatments. Patients with intermediate-risk pulmonary embolism are at high risk of clinical deterioration; however, it is unclear whether anticoagulation alone is sufficient. The optimal treatment of intermediate-risk pulmonary embolism in the setting of hemodynamic stability with right heart strain present is not well-defined. Therapies such as catheter-directed thrombolysis and suction thrombectomy are being investigated given their potential to offload right ventricular strain. Several studies have recently evaluated catheter-directed thrombolysis and embolectomies and demonstrated the efficacy and safety of these interventions. Here, we review the literature on the management of intermediate-risk pulmonary embolisms and the evidence behind those interventions.

CONCLUSIONS

There are many treatments available in the management of intermediate-risk pulmonary embolism. Although the current literature does not favor 1 treatment as superior, multiple studies have shown growing data to support catheter-directed therapies as potential options for these patients. Multidisciplinary pulmonary embolism response teams remain a key feature in improving the selection of advanced therapies and optimization of care.

Incidence Rates of Myomectomy-Related Mortality and Venous Thromboembolism in South Korea: A Population-Based Study

Background

Uterine leiomyomas are the most commonly observed pathologies, with an estimated prevalence of 4. 5–68.6%. We aimed to calculate myomectomy-related mortality and venous thromboembolism incidence rates in the Republic of Korea.

Methods

The data of patients who underwent myomectomy (2009–2018) were obtained from the Health Insurance Review and Assessment Service-National Inpatient Sample. The mortality rate after myomectomy was calculated using the leiomyoma diagnostic codes and myomectomy procedure codes. The incidence rates of venous thromboembolism, deep vein thrombosis, and pulmonary embolism were calculated using their diagnostic codes, with concomitant use of an antithrombotic agent during the same period or within 90 days after myomectomy.

Results

The data of 23,549 women aged 15–55 years who underwent myomectomy were extracted. The myomectomy rate was 14.6 ± 0.1 per 10,000 patients. The average age was 39.39 ± 0.04 years. One patient who underwent myomectomy died; this patient did not have concomitant venous thromboembolism. The post-myomectomy mortality rate was 1.3 ± 0.8 per 10,000 patients. The incidence rates of venous thromboembolism, deep vein thrombosis, and pulmonary embolism after myomectomy were 5.7 ± 1.6 per 10,000 patients, 4.4 ± 1.4 per 10,000 patients, and 2.5 ± 1 per 10,000 patients, respectively. The conversion rate to hysterectomy was 2.9 ± 1.1 per 10,000 patients.

Conclusion

The current mortality rate after myomectomy (0.013%) is substantially lower than that described in previous studies at the turn of the 20th century. The incidence of venous thromboembolism is also considerably lower than that in the general population worldwide.

Decline in Overall Pulmonary Embolism-Related Mortality and Increasing Prevalence of Cancer-Associated Events in the Veneto Region (Italy), 2008-2019

BACKGROUND

 Despite evidence of ongoing epidemiological changes in deaths from venous thromboembolism in high-income countries, little recent information is available on the time trends in mortality related to pulmonary embolism (PE) as underlying or concomitant cause of death in Europe.

METHODS

 We accessed the regional database of death certificates of Veneto Region (Northern Italy, population 4,900,000) from 2008 to 2019. We analyzed the trends in crude and age-adjusted annual rates of mortality related to PE (reported either as underlying cause or in any position in the death certificate) using Joinpoint regression; in the contribution of PE to mortality (proportionate mortality); and, using logistic regression, in the association between PE and cancer at death.

RESULTS

 Between 2008 and 2019, the annual age-standardized mortality rate related to PE in Veneto decreased from 20.7 to 12.6 deaths per 100,000 population for PE in any position of the death certificate, and from 4.6 to 2.2 deaths per 100,000 population for PE as underlying cause of death. PE-related proportionate mortality remained up to twice as high in women. The age- and sex-adjusted odds ratio for cancer in deaths with versus without PE constantly increased from 1.01 (95% confidence interval [CI]: 0.88-1.16) in 2008 to 1.58 (95% CI: 1.35-1.83) in 2019.

CONCLUSION

 The descending trends in PE-related mortality reported for Europe up to 2015 for both sexes continued thereafter in this high-income region of Northern Italy. However, sex differences in proportionate mortality persist. The increasing strength in the association between cancer and PE may indicate a change in risk factor distribution, calling for tailored management practices in this patient group.

Bilateral Pulmonary Emboli on Dabigatran

We present the case of a 44-year-old female who presented to the emergency department (ED) via emergency medical services with a chief concern of shortness of breath and was found to have bilateral pulmonary emboli (PE) while taking the direct oral anticoagulant dabigatran. The authors highlight the importance of considering PE even in patients who are on anticoagulation.

Systematic review and meta-analysis of test accuracy for the diagnosis of suspected pulmonary embolism

Pulmonary embolism (PE) is a common, potentially life-threatening yet treatable condition. Prompt diagnosis and expeditious therapeutic intervention is of paramount importance for optimal patient management. Our objective was to systematically review the accuracy of D-dimer assay, compression ultrasonography (CUS), computed tomography pulmonary angiography (CTPA), and ventilation-perfusion (V/Q) scanning for the diagnosis of suspected first and recurrent PE. We searched Cochrane Central, MEDLINE, and EMBASE for eligible studies, reference lists of relevant reviews, registered trials, and relevant conference proceedings. 2 investigators screened and abstracted data. Risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies-2 and certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework. We pooled estimates of sensitivity and specificity. The review included 61 studies. The pooled estimates for D-dimer sensitivity and specificity were 0.97 (95% confidence interval [CI], 0.96-0.98) and 0.41 (95% CI, 0.36-0.46) respectively, whereas CTPA sensitivity and specificity were 0.94 (95% CI, 0.89-0.97) and 0.98 (95% CI, 0.97-0.99), respectively, and CUS sensitivity and specificity were 0.49 (95% CI, 0.31-0.66) and 0.96 (95% CI, 0.95-0.98), respectively. Three variations of pooled estimates for sensitivity and specificity of V/Q scan were carried out, based on interpretation of test results. D-dimer had the highest sensitivity when compared with imaging. CTPA and V/Q scans (high probability scan as a positive and low/non-diagnostic/normal scan as negative) both had the highest specificity. This systematic review was registered on PROSPERO as CRD42018084669.

Vancouver General Hospital Pulmonary Embolism Response Team (VGH PERT): initial three-year experience

PURPOSE

Clinical equipoise exists with the use of novel reperfusion therapies such as catheter-directed thrombolysis in the management of patients presenting to hospital with high risk pulmonary embolism (PE). Therapeutic options rely on clinical presentation, patient factors, physician preference, and institutional availability. We established a Pulmonary Embolism Response Team (PERT) to provide urgent assessment and multidisciplinary care for patients presenting to our institution with high-risk PE.

METHODS

Data were retrospectively collected from PERT activations between January 2016 and December 2018. Chi square tests were used to determine differences in mortality across the three years of study. Logistic regression was used to evaluate 30- and 90-day mortality and occurrence of major bleeds between those receiving anticoagulation alone (AC) and those receiving advanced reperfusion therapy (ART).

RESULTS

There were 128 PERT activations over three years, the majority originating from the emergency department. Eighty-five percent of activations were for submassive PE, with 56% of all activations assessed as submassive-high risk. Fifteen patients (12%) presented with massive PE. Advanced reperfusion therapy was used in 29 (23%) patients, of whom 25 (20%) received catheter-directed thrombolysis. There was an increased risk of major bleeding in the ART group compared with in the AC group (odds ratio [OR], 17.9; 95% confidence interval [CI], 4.1 to 125.0; P < 0.001), but no increased risk of mortality at 30 days (OR, 2.1; 95% CI, 0.4 to 9.1; P = 0.3). The 30-day mortality rate was 7.8%.

CONCLUSION

We describe the first Canadian PERT, a multidisciplinary team aimed at providing urgent individualized care for patients with high-risk PE. Further research is necessary to determine whether a PERT improves clinical outcomes.

Outpatient Pulmonary Rehabilitation in Patients with Persisting Symptoms after Pulmonary Embolism

Background: Patients with pulmonary embolism (PE) may suffer from long-term consequences, including decreased functional capacity. Data on pulmonary rehabilitation (PR) in patients with PE are scarce, and no data on outpatient PR are available so far. Methods: We analyzed data of 22 PE patients who attended outpatient PR due to exertional dyspnea. Patients underwent a multi-professional 6-week PR program. The primary outcome was change in 6-min walk test (6MWT). Secondary outcomes included changes in strength and endurance tests. To assess long-term benefits, follow-up was performed a median of 39 months after PR. Results: Patients started PR a median of 19 weeks after the acute PE event. Their median age was 47.5 years, 33% were women and all presented with NYHA (New York Heart Association) class II and higher. After PR, patients showed significant and clinically relevant improvements in 6MWT (mean difference: 49.4 m [95% CI 32.0−66.8]). Similarly, patients increased performance in maximum strength, endurance and inspiratory muscle strength. At long-term follow-up, 78% of patients reported improved health. Conclusion: We observed significant improvements in exercise capacity in PE patients undergoing outpatient PR. The majority of patients also reported a long-term improvement in health status. Prospective studies are needed to identify patients who would benefit most from structured PR.

Long-term outcomes in patients with pulmonary embolism: results from a longitudinal cohort study

BACKGROUND

Patients with pulmonary embolism (PE) have increased mortality in short-term; however, long-term prognosis is not well defined.

AIM

In this long-term cohort study, we aimed to determine if PE was associated with increased risk of mortality or serious clinical events (SCE). Secondary aims were to ascertain predictors of mortality and SCE.

METHODS

Patients admitted with clinical suspicion of PE were prospectively recruited from July 2002 to May 2003 and followed up until March 2015. Clinical outcomes in patients with PE were compared to those without PE. SCE was defined as composite of mortality, malignancy, cardiovascular events, recurrent venous thromboembolism and chronic thromboembolic pulmonary hypertension.

RESULTS

A total of 501 patients with median follow up of 11.9 years (interquartile range 3.91-12.28) was included. PE was diagnosed in 104 (20.7%) patients. Overall, 45.9% died and 57.1% developed SCE during follow up, with no significant difference in PE and no-PE groups (both P > 0.5). Major determinants of mortality were age (hazard ratio (HR) 1.06 per year, 95% confidence interval (CI) 1.05-1.08), malignancy (HR 2.19, 95% CI 1.64-2.91) and congestive heart failure (HR 1.72, 95% CI 1.23-2.42). Factors associated with increased risk of SCE were age (HR 1.05 per year, 95% CI 1.04-1.06), malignancy (HR 1.93, 95% CI 1.48-2.52) and congestive heart failure (HR 1.77, 95% CI 1.29-2.43). In patients without PE, elevated D-dimer concentration was not found to be associated with diagnosis of malignancy during follow up (HR 1.31, 95% CI 0.55-3.12).

CONCLUSIONS

In this prospective study, we did not find association between PE and risk of all-cause mortality or SCE. Major determinants of poor clinical outcomes were advancing age and underlying comorbidities.

Use of pulmonary CT angiography with low tube voltage and low-iodine-concentration contrast agent to diagnose pulmonary embolism

Pulmonary CT angiography (CTPA) is regarded as the preferred imaging method in diagnosing pulmonary embolism (PE). Considering the harm of radiation exposure and the side effect of iodinated contrast agent, CTPA protocol with low tube voltage and low dose of contrast agent became research hotspot in last decade. The present study evaluates the image quality, radiation dose, positive rate of PE and the location of PE with a CTPA protocol using low tube voltage (80 kVp) and low-iodine-concentration contrast agent (270 mg I/ml) in patients suspected of PE compared to a conventional CTPA protocol (120 kVp, 350 mg I/ml). The results showed that 80 kVp CTPA protocol with 40 ml 270 mg I/ml achieved equally subjective image quality and a positive rate for diagnosing PE, though the quantitative image quality was reduced compared to the 120 kVp CTPA protocol with 40 ml 350 mg I/ml administered, with a 63.6% decrease in radiation dose and a 22.9% reduction in iodine content of contrast agent. Our results document that CTPA protocol with low tube voltage and low iodine concentration of contrast agent is satisfied to the clinical application.

Prognosis and Monitoring of VTE

Venous thromboembolism (VTE) can present in a variety of different clinical settings and in a diverse, comorbid patient population, both of which will guide the clinician toward the appropriate therapeutic response. Patients who present with pulmonary embolism are at risk for hemodynamic instability, recurrence of VTE, cardiac comorbidities, and increased risk of overall mortality. Prognostication models have been clinically validated for risk stratification and prediction of mortality. Similar to pulmonary embolism, patients with deep vein thrombosis carry a higher risk of VTE recurrence and cardiac comorbidities. Consequently, VTE can be treated by a variety of methods such as anticoagulants or inferior vena cava filters, which bear their own risks and benefits. It is imperative that clinicians monitor patients for complications from VTE and the chosen therapy.

Impact of Thrombolytic Therapy on the Long-Term Outcome of Intermediate-Risk Pulmonary Embolism

BACKGROUND

The long-term effect of thrombolytic treatment of pulmonary embolism (PE) is unknown.

OBJECTIVES

This study investigated the long-term prognosis of patients with intermediate-risk PE and the effect of thrombolytic treatment on the persistence of symptoms or the development of late complications.

METHODS

The PEITHO (Pulmonary Embolism Thrombolysis) trial was a randomized (1:1) comparison of thrombolysis with tenecteplase versus placebo in normotensive patients with acute PE, right ventricular (RV) dysfunction on imaging, and a positive cardiac troponin test result. Both treatment arms received standard anticoagulation. Long-term follow-up was included in the third protocol amendment; 28 sites randomizing 709 of the 1,006 patients participated.

RESULTS

Long-term (median 37.8 months) survival was assessed in 353 of 359 (98.3%) patients in the thrombolysis arm and in 343 of 350 (98.0%) in the placebo arm. Overall mortality rates were 20.3% and 18.0%, respectively (p = 0.43). Between day 30 and long-term follow-up, 65 deaths occurred in the thrombolysis arm and 53 occurred in the placebo arm. At follow-up examination of survivors, persistent dyspnea (mostly mild) or functional limitation was reported by 36.0% versus 30.1% of the patients (p = 0.23). Echocardiography (performed in 144 and 146 patients randomized to thrombolysis and placebo, respectively) did not reveal significant differences in residual pulmonary hypertension or RV dysfunction. Chronic thromboembolic pulmonary hypertension (CTEPH) was confirmed in 4 (2.1%) versus 6 (3.2%) cases (p = 0.79).

CONCLUSIONS

Approximately 33% of patients report some degree of persistent functional limitation after intermediate-risk PE, but CTEPH is infrequent. Thrombolytic treatment did not affect long-term mortality rates, and it did not appear to reduce residual dyspnea or RV dysfunction in these patients. (Pulmonary Embolism Thrombolysis study [PEITHO]; NCT00639743).

Systemic Thrombolysis for Pulmonary Embolism: Who and How

Anticoagulation has been shown to improve mortality in acute pulmonary embolism (PE). Initiation of anticoagulation should be considered when PE is strongly suspected and the bleeding risk is perceived to be low, even if acute PE has not yet been proven. Low-risk patients with acute PE are simply continued on anticoagulation. Severely ill patients with high-risk (massive) PE require aggressive therapy, and if the bleeding risk is acceptable, systemic thrombolysis should be considered. However, despite clear evidence that parenteral thrombolytic therapy leads to more rapid clot resolution than anticoagulation alone, the risk of major bleeding including intracranial bleeding is significantly higher when systemic thrombolytic therapy is administered. It has been demonstrated that right ventricular dysfunction, as well as abnormal biomarkers (troponin and brain natriuretic peptide) are associated with increased mortality in acute PE. In spite of this, intermediate-risk (submassive) PE comprises a fairly broad clinical spectrum. For several decades, clinicians and clinical trialists have worked toward a more aggressive, yet safe solution for patients with intermediate-risk PE. Standard-dose thrombolysis, low-dose systemic thrombolysis, and catheter-based therapy which includes a number of devices and techniques, with or without low-dose thrombolytic therapy, have offered potential solutions and this area has continued to evolve. On the basis of heterogeneity within the category of intermediate-risk as well as within the high-risk group of patients, we will focus on the use of systemic thrombolysis in carefully selected high- and intermediate-risk patients. In certain circumstances when the need for aggressive therapy is urgent and the bleeding risk is acceptable, this is an appropriate approach, and often the best one.

Diagnosis of acute pulmonary embolism

Advances in the management of patients with suspected pulmonary embolism (PE) have improved diagnostic accuracy and made management algorithms safer, easier to use, and well standardized. These diagnostic algorithms are mainly based on the assessment of clinical pretest probability, D-dimer measurement, and imaging tests-predominantly computed tomography pulmonary angiography. These diagnostic algorithms allow safe and cost-effective diagnosis for most patients with suspected PE. In this review, we summarize signs and symptoms of PE, current existing evidence for PE diagnosis, and focus on the challenge of diagnosing PE in special patient populations, such as pregnant women, or patients with a prior VTE. We also discuss novel imaging tests for PE diagnosis and highlight some of the additional challenges that might require adjustments to current diagnostic strategies, such as the reduced clinical suspicion threshold, resulting in a lower proportion of PE among suspected patients as well as the overdiagnosis of subsegmental PE.

Vascular Causes of Syncope: An Emergency Medicine Review

BACKGROUND

Syncope is a common emergency department (ED) complaint, accounting for 2% of visits annually. A wide variety of etiologies can result in syncope, and vascular causes may be deadly.

OBJECTIVE

This review evaluates vascular causes of syncope and their evaluation and management in the ED.

DISCUSSION

Syncope is defined by a brief loss of consciousness with loss of postural tone and complete, spontaneous recovery without medical intervention. Causes include cardiac, vasovagal, orthostatic, neurologic, medication-related, and idiopathic, and most cases of syncope will not receive a specific diagnosis pertaining to the cause. Emergency physicians are most concerned with life-threatening causes such as dysrhythmia and obstruction, and electrocardiogram is a primary means of evaluation. However, vascular etiologies can result in patient morbidity and mortality. These conditions include pulmonary embolism, subclavian steal, aortic dissection, cerebrovascular disease, intracerebral hemorrhage, carotid/vertebral dissection, and abdominal aortic aneurysm. A focused history and physical examination can assist emergency physicians in determining the need for further testing and management.

CONCLUSIONS

Syncope is common and may be the result of a deadly condition. The emergency physician, through history and physical examination, can determine the need for further evaluation and resuscitation of these patients, with consideration of vascular etiologies of syncope.

Late outcomes after acute pulmonary embolism: rationale and design of FOCUS, a prospective observational multicenter cohort study

Acute pulmonary embolism (PE) is a frequent cause of death and serious disability. The risk of PE-associated mortality and morbidity extends far beyond the acute phase of the disease. In earlier follow-up studies, as many as 30 % of the patients died during a follow-up period of up to 3 years, and up to 50 % of patients continued to complain of dyspnea and/or poor physical performance 6 months to 3 years after the index event. The most feared ‘late sequela’ of PE is chronic thromboembolic pulmonary hypertension (CTEPH), the true incidence of which remains obscure due to the large margin of error in the rates reported by mostly small, single-center studies. Moreover, the functional and hemodynamic changes corresponding to early, possibly reversible stages of CTEPH, have not been systematically investigated. The ongoing Follow-Up after acute pulmonary embolism (FOCUS) study will prospectively enroll and systematically follow, over a 2-year period and with a standardized comprehensive program of clinical, echocardiographic, functional and laboratory testing, a large multicenter prospective cohort of 1000 unselected patients (all-comers) with acute symptomatic PE. FOCUS will possess adequate power to provide answers to relevant remaining questions regarding the patients’ long-term morbidity and mortality, and the temporal pattern of post-PE abnormalities. It will hopefully provide evidence for future guideline recommendations regarding the selection of patients for long-term follow-up after PE, the modalities which this follow-up should include, and the findings that should be interpreted as indicating progressive functional and hemodynamic post-PE impairment, or the development of CTEPH.