Dual-Energy CT Pulmonary Angiography for the Assessment of Surgical Accessibility in Patients with Chronic Thromboembolic Pulmonary Hypertension.

Matthias Eberhard,Silvia Ulrich,Mona Lichtblau,Thomas Frauenfelder,Micheal Mcinnis,Ilhan Inci,Marc De Perrot,Isabelle Opitz

doi:10.3390/diagnostics12020228

Abstract

We assessed the value of dual-energy CT pulmonary angiography (CTPA) for classification of the level of disease in chronic thromboembolic pulmonary hypertension (CTEPH) patients compared to the surgical Jamieson classification and prediction of hemodynamic changes after pulmonary endarterectomy. Forty-three CTEPH patients (mean age, 57 ± 16 years; 18 females) undergoing CTPA prior to surgery were retrospectively included. “Proximal” and “distal disease” were defined as L1 and 2a (main and lobar pulmonary artery [PA]) and L2b-4 (lower lobe basal trunk to subsegmental PA), respectively. Three radiologists had a moderate interobserver agreement for the radiological classification of disease (k = 0.55). Sensitivity was 92–100% and specificity was 24–53% to predict proximal disease according to the Jamieson classification. A median of 9 segments/patient had CTPA perfusion defects (range, 2–18 segments). L1 disease had a greater decrease in the mean pulmonary artery pressure (p = 0.029) and pulmonary vascular resistance (p = 0.011) after surgery compared to patients with L2a to L3 disease. The extent of perfusion defects was not associated with the level of disease or hemodynamic changes after surgery (p > 0.05 for all). CTPA is highly sensitive for predicting the level of disease in CTEPH patients with a moderate interobserver agreement. The radiological level of disease is associated with hemodynamic improvement after surgery.

Highlights

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare, progressive pulmonary vascular disease [1,2]
This study aimed (i) to assess the predictive value of a radiological classification of the level of disease in chronic thromboembolic pulmonary hypertension (CTEPH) patients on CT pulmonary angiography (CTPA) using the surgical classification as a standard of reference, (ii) to assess whether perfusion defects assessed on dual-energy computed tomography (CT) iodine maps correlate with the radiological level of disease assessed on CTPA, and (iii) to assess the association of the radiological level of CTEPH and the extent of perfusion defects with the improvement of hemodynamics after surgery
In all patients included in the final analysis (n = 43), the diagnosis of CTEPH was confirmed in a multidisciplinary conference, including a thoracic surgeon, a pulmonologist, and a radiologist following guidelines for the diagnosis of group 4 pulmonary hypertension [21]

Summary

Introduction

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare, progressive pulmonary vascular disease [1,2]. It is most commonly a sequela of prior venous thromboembolism with an incidence between 0.4% and 6.2%, confirmed by right heart catheterization [2,3,4]. Surgical accessibility is determined in part by the most proximal extent of chronic thromboembolic changes [8,9]. This Jamieson classification scheme is based on intraoperative findings and there are limited reports on its correlation with preoperative imaging [9,10]. Patients deemed inoperable based on comorbidities, or with extensive distal disease not accessible to surgery, may be candidates for medical therapy and/or balloon pulmonary angioplasty but these therapies are not curative [1,11]

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