Pulmonary vascular imaging characteristics after pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension

J Heart Lung Transplant. 2020 Mar;39(3):248-256. doi: 10.1016/j.healun.2019.11.020. Epub 2019 Dec 5.

Abstract

Background: Between 16% and 51% of patients with chronic thromboembolic pulmonary hypertension will have residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). Whether residual PH is related to remaining (sub-)segmental macrovascular lesions or to microvascular disease is unknown. New imaging techniques can provide detailed information about (sub-)segmental pulmonary arteries and parenchymal perfusion. The aim of this study was to describe the prevalence after PEA of remaining (sub-)segmental vascular lesions on electrocardiogram-gated computed tomography pulmonary angiography (CTPA) and parenchymal hypoperfusion on magnetic resonance imaging (MRI) and to relate these imaging abnormalities to the presence or absence of residual PH after PEA.

Methods: In a prospective cohort of patients with operable chronic thromboembolic pulmonary hypertension, hemodynamics, CTPA, and lung perfusion MRI were performed before and 6 months after PEA. The percentage of (sub-)segmental vascular lesions was calculated on CTPA and parenchymal hypoperfusion on lung perfusion MRI.

Results: PEA led to significant improvements in hemodynamics and a reduction of imaging abnormalities. Residual PH was present in 45% of patients after PEA, whereas remaining (sub-)segmental vascular lesions and parenchymal hypoperfusion were present in 20% and 21% of the pulmonary vasculature, respectively. Patients with and without residual PH after PEA had similar percentages of remaining (sub-)segmental vascular lesions (25% ± 14% vs 17% ± 15%; p = 0.16) and similar degrees of parenchymal hypoperfusion (20% ± 7% vs 19% ± 6%; p = 0.63).

Conclusions: After successful PEA, advanced imaging shows that around 20% of the pulmonary vasculature remains abnormal, independent of the presence of residual PH. This may suggest that microvascular disease, rather than residual macrovascular lesions, plays a prominent role in residual PH after PEA.

Keywords: chronic thromboembolic pulmonary hypertension; computed tomography angiography; magnetic resonance imaging; pulmonary endarterectomy; residual pulmonary hypertension.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chronic Disease
  • Computed Tomography Angiography / methods*
  • Endarterectomy*
  • Female
  • Follow-Up Studies
  • Humans
  • Hypertension, Pulmonary / diagnosis*
  • Hypertension, Pulmonary / etiology
  • Hypertension, Pulmonary / physiopathology
  • Lung / diagnostic imaging
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Postoperative Period
  • Prospective Studies
  • Pulmonary Artery / diagnostic imaging*
  • Pulmonary Artery / surgery
  • Pulmonary Embolism / complications*
  • Pulmonary Embolism / physiopathology
  • Pulmonary Embolism / surgery
  • Tomography, X-Ray Computed / methods*