Combined Use of Angiography, Optical Coherence Tomography and Intravascular Ultrasound in Evaluation of Pulmonary Vascular Structure and Function in Patients With Pulmonary Arterial Hypertension Treated With Oral Bosentan

Study Overview
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Brief Summary
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It has been hypothesized that one of the benefits of bosentan relates to pulmonary vascular remodeling. The investigators believe that this study will help document the nature of beneficial changes that occur in patients with Pulmonary Arterial Hypertension (PAH) in response to bosentan therapy. In turn, demonstrating that changes in pulmonary vascular structure and function accompany clinical improvement.

Detailed Description
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Subjects will have Optical coherence tomography (OCT) and Intravascular Ultrasound (IVUS) imaging during the right heart catheterization that diagnoses them as having PAH. Subjects will start their bosentan and will be followed by monthly clinic visits for 4 months. At 4 months they will have repeat OCT and IVUS imaging.

Official Title
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Combined Use of Angiography, Optical Coherence Tomography and Intravascular Ultrasound in Evaluation of Pulmonary Vascular Structure and Function in Patients With Pulmonary Arterial Hypertension Treated With Oral Bosentan

Conditions
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Pulmonary Arterial Hypertension

Intervention / Treatment
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* Device: St Jude Medical C7 Dragonfly Optical Coherence Tomography (OCT)
* Device: Boston Scientific Intravascular Ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: WHO GROUP 1 AGE 18-75 Baseline 6-min walk distance (6MWD) between 200 and 450 m Diagnosed with pulmonary artery hypertension during right heart catheterization (Mean Pulmonary Artery Pressure > 25mmHg) General Exclusion Criteria Pregnant or nursing Acute or chronic illness other than those associated with PAH (collagen vascular disease, human immunodeficiency virus, or anorexigen use) Previously received any investigational medications, prostanoids, or phosphodiesterase inhibitors eGFR < 60 Angina Syncope Failing right ventricle Hemoptysis

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Pulmonary Arterial Hypertension, bosentan<br>Subjects include patients being diagnosed with pulmonary arterial hypertension and starting treatment with bosentan. | Device: St Jude Medical C7 Dragonfly Optical Coherence Tomography (OCT)<br>* All subjects will have OCT and IVUS imaging during their right heart catheterization.<br>Device: Boston Scientific Intravascular Ultrasound<br>* All subjects will have OCT and IVUS imaging during their right heart catheterization.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the measurement of Pulmonary arterial intimal + Medial thickening by OCT pre and post treatment with bosentan at 4 months |  | Baseline and 4 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in pulmonary arterial pulsatility by IVUS pre and post treatment with bosentan at 4 months |  | Baseline and 4 months | 
| Change in pulmonary arterial pressure/elastic strain index by IVUS pre and post treatment with bosentan at 4 months |  | Baseline and 4 months |