Pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: pathophysiology

Abstract

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are two of the key subgroups of pulmonary hypertension. They are characterised by different risk factors. PAH can be associated with mutations in the gene encoding bone morphogenetic protein receptor type II (BMPR2), HIV infection, congenital heart disease, connective tissue disease (such as systemic sclerosis), and exposure to particular drugs and toxins including fenfluramine derivatives. In contrast, CTEPH can be associated with antiphospholipid antibodies, splenectomy and the presence of a ventriculo-atrial shunt or an infected pacemaker.The first-line therapies used to treat PAH and CTEPH also differ. While medical therapy tends to be used for patients with PAH, pulmonary endarterectomy is the treatment of choice for patients with CTEPH.However, there are possible common mechanisms behind the two diseases, including endothelial cell dysfunction and distal pulmonary artery remodelling. Further research into these similarities is needed to assist the development of targeted pharmacological therapies for patients with inoperable CTEPH and patients who have persistent pulmonary hypertension after endarterectomy.

Red cell distribution width

“…Intraluminal in situ thrombus, fibrous stenosis, and total obliteration of pulmonary arteries by pulmonary arteriopathy are characteristic features of CTEPH. 5,[17][18][19] The risk for the development of CTEPH is increased when PE is detected in young or old age having large perfusion defects, during recurrent or unprovoked (idiopathic) PE, when pulmonary artery systolic pressure is >50 mm Hg at initial manifestation of PE, and when there is persistent pulmonary hypertension on ECHO performed 6 months after acute PE is detected. 5,20-22 CTEPH condition occurs due to chronic medical risk factors that lead to the development of chronic inflammatory disorders such as osteomyelitis and inflammatory bowel disease, myeloproliferative syndromes, the presence of a ventriculoatrial shunt, and splenectomy.…”

Sequential Hybrid Therapy With Pulmonary Endarterectomy and Additional Balloon Pulmonary Angioplasty for Chronic Thromboembolic Pulmonary Hypertension

“…Chronic thromboembolic pulmonary hypertension (CTEPH) is characterized by stenoses and obstruction of the pulmonary arteries caused by organized thrombus 1, 2, 3, 4, 5. Without being treated, the prognosis is so poor that a 5‐year survival rate in patients with a mean pulmonary artery pressure (mPAP) >50 mm Hg is 10% 6.…”

Right ventricular reserve in a piglet model of chronic pulmonary hypertension

“…Survival in patients with pulmonary hypertension (PH) is closely related to right ventricular (RV) function [1][2][3]. In haemodynamics-based studies, low cardiac index (CI) and increased right atrial pressure (RAP) at rest are strong predictors of outcome [4].…”