Microvascular Disease in Chronic Thromboembolic Pulmonary Hypertension: Hemodynamic Phenotyping and Histomorphometric Assessment

Abstract Objectives The aim of this study was to describe the radiological features of chronic thromboembolic pulmonary disease (CTEPD), not yet systematically described in the literature. Furthermore, we compared vascular scores between CTEPD and chronic thromboembolic pulmonary hypertension (CTEPH) patients, trying to explain why pulmonary hypertension does not develop at rest in CTEPD patients. Methods Eighty-five patients (40 CTEPD, 45 CTEPH) referred to our centre for pulmonary endarterectomy underwent dual-energy computed tomography pulmonary angiography (DE-CTPA) with iodine perfusion maps; other 6 CTEPD patients underwent single-source CTPA. CT scans were reviewed independently by an experienced cardiothoracic radiologist and a radiology resident to evaluate scores of vascular obstruction, hypoperfusion and mosaic attenuation, signs of pulmonary hypertension and other CT features typical of CTEPH. Results Vascular obstruction burden was similar in the two groups (p = 0.073), but CTEPD patients have a smaller extension of perfusion defects in the iodine map (p = 0.009) and a smaller number of these patients had mosaic attenuation (p < 0.001) than CTEPH patients, suggesting the absence of microvascular disease. Furthermore, as expected, the two groups were significantly different considering the indirect signs of pulmonary hypertension (p < 0.001). Conclusions CTEPD and CTEPH patients have significantly different radiological characteristics, in terms of signs of pulmonary hypertension, mosaic attenuation and iodine map perfusion extension. Importantly, our results suggest that the absence of peripheral microvascular disease, even in presence of an important thrombotic burden, might be the reason for the absence of pulmonary hypertension in CTEPD. Key Points • CTEPD and CTEPH patients have significantly different radiological characteristics. • The absence of peripheral microvascular disease might be the reason for the absence of pulmonary hypertension in CTEPD.

Download Full-text

Pulmonary Microvascular Disease in Chronic Thromboembolic Pulmonary Hypertension

Proceedings of the American Thoracic Society ◽

10.1513/pats.200605-113lr ◽

2006 ◽

Vol 3 (7) ◽

pp. 571-576 ◽

Cited By ~ 119

Author(s):

N. Galie

Keyword(s):

Pulmonary Hypertension ◽

Chronic Thromboembolic Pulmonary Hypertension ◽

Microvascular Disease ◽

Thromboembolic Pulmonary Hypertension

Download Full-text

Microvascular disease in chronic thromboembolic pulmonary hypertension: a role for pulmonary veins and systemic vasculature

European Respiratory Journal ◽

10.1183/09031936.00169113 ◽

2014 ◽

Vol 44 (5) ◽

pp. 1275-1288 ◽

Cited By ~ 97

Author(s):

Peter Dorfmüller ◽

Sven Günther ◽

Maria-Rosa Ghigna ◽

Vincent Thomas de Montpréville ◽

David Boulate ◽

...

Keyword(s):

Pulmonary Hypertension ◽

Pulmonary Veins ◽

Pulmonary Arteries ◽

Chronic Thromboembolic Pulmonary Hypertension ◽

Microvascular Disease ◽

Pulmonary Endarterectomy ◽

Functional Importance ◽

Lung Histology ◽

Thromboembolic Pulmonary Hypertension ◽

History Of

Limited numbers of operated patients with chronic thromboembolic pulmonary hypertension (CTEPH) are refractory to pulmonary endarterectomy (PEA) and experience persistent pulmonary hypertension (PH).We retrospectively assessed lung histology available from nine patients with persistent PH (ineffective PEA (inPEA) group) and from eight patients transplanted for distal CTEPH inaccessible by PEA (noPEA group). Microscopically observed peculiarities were compared with the histology of a recently developed CTEPH model in piglets. Pre-interventional clinical/haemodynamic data and medical history of patients from the inPEA and noPEA groups were collected and analysed.Conspicuous remodelling of small pulmonary arteries/arterioles, septal veins and pre-septal venules, including focal capillary haemangiomatosis, as well as pronounced hypertrophy and enlargement of bronchial systemic vessels, were the predominant pattern in histology from both groups. Most findings were reproduced in our porcine CTEPH model. Ink injection experiments unmasked abundant venular involvement in so-called small vessel or microvascular disease, as well as post-capillary bronchopulmonary shunting in human and experimental CTEPH.Microvascular disease is partly due to post-capillary remodelling in human and experimental CTEPH and appears to be related to bronchial-to-pulmonary venous shunting. Further studies are needed to clinically assess the functional importance of this finding.

Download Full-text