Clinical and imaging outcomes after intermediate- or high-risk pulmonary embolus

Long-term outcomes of pulmonary embolism in children and adolescents

ABSTRACT

Knowledge regarding the long-term consequences of pulmonary embolism (PE) in children is limited. This cohort study describes the long-term outcomes of PE in children who were followed-up at a single-center institution using a local protocol that included clinical evaluation, chest imaging, echocardiography, pulmonary function tests, and cardiopulmonary exercise tests at follow-up, starting 3 to 6 months after acute PE. Children objectively diagnosed with PE at age 0 to 18 years, who had ≥6 months of follow-up were included. Study outcomes consisted of PE resolution, PE recurrence, death, and functional outcomes (dyspnea, impaired pulmonary or cardiac function, impaired aerobic capacity, and post-PE syndrome). The frequency of outcomes was compared between patients with/without underlying conditions. In total, 150 patients were included; median age at PE was 16 years (25th-75th percentile, 14-17 years); 61% had underlying conditions. PE did not resolve in 29%, recurrence happened in 9%, and death in 5%. One-third of patients had at least 1 documented abnormal functional finding at follow-up (ventilatory impairments, 31%; impaired aerobic capacity, 31%; dyspnea, 26%; and abnormal diffusing capacity of the lungs to carbon monoxide, 22%). Most abnormalities were transient. When alternative explanations for the impairments were considered, the frequency of post-PE syndrome was lower, ranging between 0.7% and 8.5%. Patients with underlying conditions had significantly higher recurrence, more pulmonary function and ventilatory impairments, and poorer exercise capacity. Exercise intolerance was, in turn, most frequently because of deconditioning than to respiratory or cardiac limitation, highlighting the importance of physical activity promotion in children with PE.

Evaluating cardiopulmonary function following acute pulmonary embolism

INTRODUCTION

Pulmonary embolism is a common cause of cardiopulmonary mortality and morbidity worldwide. Survivors of acute pulmonary embolism may experience dyspnea, report reduced exercise capacity, or develop overt pulmonary hypertension. Clinicians must be alert for these phenomena and appreciate the modalities and investigations available for evaluation.

AREAS COVERED

In this review, the current understanding of available contemporary imaging and physiologic modalities is discussed, based on available literature and professional society guidelines. The purpose of the review is to provide clinicians with an overview of these modalities, their strengths and disadvantages, and how and when these investigations can support the clinical work-up of patients post-pulmonary embolism.

EXPERT OPINION

Echocardiography is a first test in symptomatic patients post-pulmonary embolism, with ventilation/perfusion scanning vital to determination of whether there is chronic residual emboli. The role of computed tomography and magnetic resonance in assessing the pulmonary arterial tree in post-pulmonary embolism patients is evolving. Functional testing, in particular cardiopulmonary exercise testing, is emerging as an important modality to quantify and determine cause of functional limitation. It is possible that future investigations of the post-pulmonary embolism recovery period will better inform treatment decisions for acute pulmonary embolism patients.

An Untapped Resource: Characteristics of Thrombus Recovered from Intermediate or High Risk Pulmonary Embolus Patients

INTRODUCTION

Response to anticoagulation varies during management of acute hospitalized pulmonary embolism. We aimed to study thrombus histology in pulmonary embolism samples removed during acute surgical embolectomy to evaluate whether thrombus morphology was similar between patients and whether there was an association with duration of symptoms and/or resolution on follow up imaging.

METHODS

This was a retrospective observational single center study at the University of Rochester Medical Center. We evaluated patients that underwent acute surgical embolectomy and followed up in our clinic 2-4 months after the event with Ventilation/Perfusion (V/Q) scan obtained for all regardless of symptoms. Thromboemboli were formalin fixed and processed for light microscopy in the hospital histopathology laboratory. Four-micron thick sections were stained with hematoxylin and eosin, Masson trichrome, and Verhoeff elastic tissue stains. Immunohistochemistry was performed using anti-CD31 and anti-CD68. Slides were independently evaluated for time-dependent microscopic changes using Irniger's classification by two blinded pathologists.

RESULTS

Sixteen patients underwent embolectomy with fifteen having V/Q imaging at follow up. The majority of patients were female. Samples showed a generally similar overall architecture that included a central core composed primarily of red blood cells and fibrin and an outer layer of platelets and monocytes. Two samples had evidence of fibrosis and recanalization.

CONCLUSIONS

We found heterogeneous histopathology in samples obtained during acute embolectomy. Further prospective studies should systematically characterize clot morphology and evaluate treatment response and outcomes. Careful thrombus specimen measurement and consistent sampling for sections will be required to draw firm conclusions.

Resting heart rate as a surrogate for improvement in intermediate risk pulmonary embolus patients?

BACKGROUND

Pulmonary embolism (PE) response teams (PERT) have been developed to improve in-hospital mortality. Identifying intermediate risk PE patients that will progress despite anticoagulation is difficult, especially because outcomes with modern anticoagulation are quite good.

OBJECTIVE

The primary aim of this study was to evaluate the rate of anticoagulation failure (new deep vein thrombosis or PE, right ventricular failure resulting in shock, cardiac arrest, or PE-attributable death) in intermediate risk PE patients managed by PERT. The secondary objective was to determine whether there was a significant decrease in heart rate 24 h after initiation of anticoagulation in intermediate risk PE.

METHODS

This was a retrospective observational study of patients treated for acute intermediate risk PE at the University of Rochester Medical Center who also had outpatient followup between November 2016-June 2019.

RESULTS

Ninety-two patients presented as intermediate-risk PE and had outpatient followup. Seventy-four patients were initially treated with anticoagulation. None of these patients failed anticoagulation. Of the eighteen intermediate risk patients that underwent advanced intervention, none failed anticoagulation first. There was significant decrease in resting heart rate 24 h after starting therapeutic anticoagulation, 107 beats/min vs 89 beats/min, p = 0.0001.

CONCLUSION

We did not observe anticoagulation failure in the management of acute, intermediate risk PE. Reductions in heart rate may reflect improvements in right ventricular function; we hypothesize that those whose heart rate does not fall may be optimal candidates for advanced intervention.

Determinants and Management of the Post-Pulmonary Embolism Syndrome

Acute pulmonary embolism (PE) is not only a serious and potentially life-threatening disease in the acute phase, in recent years it has become evident that it may also have a major impact on a patient's daily life in the long run. Persistent dyspnea and impaired functional status are common, occurring in up to 50% of PE survivors, and have been termed the post-PE syndrome (PPES). Chronic thromboembolic pulmonary hypertension is the most feared cause of post-PE dyspnea. When pulmonary hypertension is ruled out, cardiopulmonary exercise testing can play a central role in investigating the potential causes of persistent symptoms, including chronic thromboembolic pulmonary disease or other cardiopulmonary conditions. Alternatively, it is important to realize that post-PE cardiac impairment or post-PE functional limitations, including deconditioning, are present in a large proportion of patients. Health-related quality of life is strongly influenced by PPES, which emphasizes the importance of persistent limitations after an episode of acute PE. In this review, physiological determinants and the diagnostic management of persistent dyspnea after acute PE are elucidated.

Direct oral anticoagulant therapy in patients with morbid obesity after intermediate- or high-risk pulmonary emboli

There is little reported on the efficacy and safety of direct oral anticoagulants (DOACs) in morbid obesity after venous thromboembolism (VTE). In this observational study, patients were followed up after intermediate- or high-risk pulmonary embolism (PE) at the University of Rochester Pulmonary Hypertension Clinic 2-4 months after the initial event. All patients had echocardiography and V/Q imaging regardless of symptoms. Outcomes of interest were the rates of recurrent VTE, thrombus resolution and development of chronic thromboembolic pulmonary hypertension (CTEPH) in patients with morbid obesity treated with a DOAC compared to treatment with vitamin K antagonists and to non-morbidly obese patients after PE. Using the electronic medical record, recurrent events were assessed up to 12 months after the event. 107 patients (body mass index (BMI)>40 kg·m^-2, n=32; BMI 30-39.9 kg·m^-2, n=39; BMI<30 kg·m^-2, n=36) attended follow-up appointments after treatment for PE. A DOAC was used in 70 patients (BMI>40 kg·m^-2, n=19; BMI 30-39.9 kg·m^-2, n=27; BMI<30 kg·m^-2, n=24). There were no recurrent events within the first 12 months of initial diagnosis based on symptoms and imaging in any patient. There was no difference in rate of residual unmatched perfusion defect with DOACs or conventional anticoagulation (49% versus 49%). This finding remained in the subset of morbidly obese patients (47% versus 50%). For the overall cohort, there was no difference in the rate of CTEPH development based on anticoagulation with a DOAC (5% versus 8% with warfarin). There were no major bleeding complications with a DOAC. DOAC therapy appears to be effective and safe in morbid obesity even after intermediate- or high-risk PE. ​.