Longitudinal Study to Identify Predictive Factors of Post-thrombotic Pulmonary Hypertension

Rationale

Pulmonary hypertension (PH) post pulmonary thromboembolisms is a serious and complex disease, is one major cause of pulmonary hypertension (1). It is the most feared late complication of pulmonary thromboembolism (PT) characterized by the organization of thrombotic material within the pulmonary arteries (2). Although a purely mechanical theory is too simplistic in view of the lack of correlation between the proportion of obliterated pulmonary arteries and the numbers of PH.

Acute, symptomatic, or asymptomatic PT may be the initial event, but disease progression would result from progressive vascular remodeling of small vessels. It is possible that unresolved pulmonary arterial thrombosis is a decisive factor for vascular endothelial cells to initiate their mesenchymal transition (3).

On the other hand, Pulmonary hypertension post pulmonary thromboembolisms is the only subclass of pulmonary hypertension that has a curative surgical treatment (4). The diagnosis of this situation should be detected as soon as possible to optimize the results of surgical and pharmacological treatment. Surgical indication should be established as early as possible to avoid progression (5).

Hypothesis

The current data on the incidence of PH are very variable, depending on the different studies designs. There are no data on the prognostic of PH in patients with asymptomatic PT, neither paucisymptomatic PH, in which without a prospective follow-up would be underdiagnosed. We thought that the prognosis of both clinical forms (PT with or without symptoms) would be similar. Also we thought and that there are forms of paucisymptomatic PH whose diagnosis and treatment would benefit from a prospective follow-up.

Objectives

Main objective

To know the incidence of pulmonary hypertension (PH) post symptomatic and asymptomatic pulmonary thromboembolic (PT).

The secondary objectives of the study are:

• To defined clinical subtypes of PT with a predictive value of diagnosis of PH in two years.
• To Measure biomarkers described that may be related to the diagnosis of PH or the disease progression.
• Use of genetic, proteomic, RNA transcription, cytometric and cellular and metabolic identification assays to aid in the search for new genetic factors and / or PH biomarkers.

Inclusion criteria

• Patients 18 years or older and able to provide informed consent
• Diagnosis of pulmonary thromboembolisms confirmed by
• Computed Tomography Angiography (CTA) if there are a partial transluminal defect surrounded by contrast or a complete occlusion of pulmonary artery.
• Pulmonary ventilation/perfusion scan.- Patients with high risk based on PIOPED study criteria or in patients with deep venous thrombosis confirmed by echography and positron emission tomography (PET) scan not concluding.

Exclusion criteria

• Any contraindication to the performance of the pulmonary hypertension diagnostic tests
• Any circumstance, to investigator criteria, to impede the patient follow up
• Life expectancy lower than 6 months