Signs of chronic thromboembolic pulmonary hypertension in acute pulmonary embolism: results from the FOCUS study

Background/Introduction

Chronic thromboembolic pulmonary hypertension (CTEPH) is considered to be a late complication of acute pulmonary embolism (PE). However, up to one third of CTEPH patients do not report prior symptomatic venous thromboembolism (VTE). Furthermore, a substantial proportion of patients presenting with an acute PE event may exhibit radiological signs of chronicity at baseline computed tomography pulmonary angiography (CTPA).

Purpose

To determine the prevalence of baseline radiological parameters indicating chronic thrombosis or pulmonary hypertension, and ultimately pre-existing CTEPH, among patients with acute PE enrolled in the prospective multicentre Follow-Up after Acute Pulmonary Embolism (FOCUS) cohort study.

Methods

Patients with acute symptomatic PE and absence of a known history of CTEPH, enrolled at two large FOCUS centres, were included. The assessment of index CTPA scans was conducted by two independent expert radiologists who were unaware of the clinical characteristics and the follow-up data of the patients. CTPA parameters indicating chronicity were prespecified on the basis of recently proposed criteria in the literature. A third independent expert radiologist provided an assessment in case of disagreement between the first two. Baseline radiological data were prospectively validated with the aid of two-year prospective clinical follow-up data focusing on CTEPH and the post-PE syndrome (co-primary outcomes of the FOCUS study).

Results

A total of 303 patients (median age: 63 years, 44.6% women) were included. In >95% of the patients, the expert radiologists could confirm signs of acute PE at baseline CTPA. Radiological signs of chronic thrombi or pulmonary hypertension at baseline were detected in 46 (15.2%) patients. In 8 patients, the expert radiologists agreed on the presence of pre-existing CTEPH based on their interpretation of the overall radiological pattern. During follow-up, five (1.7%; 95% CI 0.7–3.8%) of 303 patients were diagnosed with CTEPH, over a median time of 95 days after baseline. Four of them were among the 8 patients in whom the radiological experts suspected pre-existing CTEPH at baseline, and among the 46 patients in whom CTPA findings suggesting chronic thrombi or chronic pulmonary hypertension were present at baseline. The use of the predefined individual parameters of chronicity from the literature also helped identifying patients with chronic disease, and could be used as a tool for screening acute PE patients for pre-existing CTEPH.

Conclusion

A substantial proportion of patients who are diagnosed with CTEPH during follow-up after acute PE may already have pre-existing CTEPH at the time of the index event. An intensified follow-up programme and focussed screening for CTEPH should be considered in patients with signs of chronicity at baseline CTPA.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bayer Health Care

Chronic thromboembolic pulmonary hypertension (CTEPH) - potential role of multidetector-row CT (MD-CT) and MR imaging in the diagnosis and differential diagnosis of the disease

Chronic thromboembolic pulmonary hypertension (CTEPH) can be defined as pulmonary hypertension (resting mean pulmonary arterial pressure of 25 mm Hg or more determined at right heart catheterization) with persistent pulmonary perfusion defects. It is a rare, but underdiagnosed disease with estimated incidences ranging from 0.5% to 3.8% of patients after an acute pulmonary embolism (PE), and in up to 10% of those with a history of recurrent PE. CTEPH is the only form of pulmonary hypertension that can be surgically treated leading to normalization of pulmonary hemodynamics and exercise capacity in the vast majority of patients. The challenges for imaging in patients with suspected CTEPH are fourfold: the imaging modality should have a high diagnostic accuracy with regard to the presence of CTEPH and allow for differential diagnosis. It should enable detection of patients suitable for PEA with great certainty, and allow for quantification of PH by measuring pulmonary hemodynamics (mPAP and PVR), and finally, it can be used for therapy monitoring. This overview tries to elucidate the potential role of ECG-gated multidetector CT pulmonary angiography (MD-CTPA) and MR imaging, and summarizes the most important results that have been achieved so far. Generally speaking, ECG-gated MD-CTPA is superior to MR in the assessment of parenchymal and vascular pathologies of the lung, and allows for the assessment of cardiac structures. The implementation of iodine maps as a surrogate for lung perfusion enables functional assessment of lung perfusion by CT. MR imaging is the reference standard for the assessment of right heart function and lung perfusion, the latter delineating typical wedge-shaped perfusion defects in patients with CTEPH. New developments show that with MR techniques, an estimation of hemodynamic parameters like mean pulmonary arterial pressure and pulmonary vascular resistance will be possible. CT and MR imaging should be considered as complementary investigations providing comprehensive information in patients with CTEPH.

[Surgical therapy of segmental jejunal, primary intestinal lymphangiectasia]

Primary intestinal lymphangiectasia (PIL) is a protein-losing, exsudative gastroenteropathy causing lymphatic obstruction. Diagnosis depends on clinical examination and histological findings. Conservative treatment modalities include a low-fat diet and enteral nutritional therapy in order to reduce enteric protein loss and to improve fat metabolism. Other treatment options consist of administration of antiplasmin or octreotide to lower lymph flow and secretion. We report on a 58-year-old patient who underwent exploratory laparotomy due to a worsening physical status, recurrent chylaskos and leg oedema under conservative dietary therapy. Intraoperative findings showed a typical PIL of the jejunum about 20 cm distal to the Treitz's ligament. Histological examinations confirmed this diagnosis. One year after segmental small bowel resection (105 cm) with end-to-end anastomosis the patient is healthy, free of symptoms, has gained weight and his serum protein level has increased. Intraabdominal ascites and leg oedema have not reoccurred since.