Platelet Reactivity and Treatment With Prostacyclin Analogues in Pulmonary Arterial Hypertension

Study Overview
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Brief Summary
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Background: Prostacyclin analogues (epoprostenol, treprostinil and iloprost) induce vasodilation in advanced pulmonary arterial hypertension (PAH) but also inhibit platelets, increasing patients' bleeding risk. The antiplatelet effects of different prostacyclin analogues have never been compared head-to-head. The goal of the PAPAYA (Platelet Reactivity and Treatment With Prostacyclin Analogues in Pulmonary Arterial Hypertension) trial is(i) to compare platelet function (platelet reactivity, extracellular vesicles concentration and thrombus formation) in patients with PAH treated with prostacyclin analogues on top of endothelin receptor antagonists (ERA) and/or phosphodiesterase type 5 inhibitors (PDE5i) and patients treated only with ERA and PDE5i, and (ii) to compare the antiplatelet effect of different prostacyclin analogues. Venous blood will be collected from patients treated with prostacyclin analogues (study group; n=40) and patients treated with ERA or PDE5i (control group; n=40). Platelet reactivity will be analysed in whole blood by impedance aggregometry using arachidonic acid, adenosine diphosphate and thrombin receptor-activating peptide as agonists. Concentrations of extracellular vesicles from all platelets (CD61+), activated platelets (CD62P+), leukocytes (CD45+) and endothelial cells (CD146+) will be analysed in platelet-depleted plasma using flow cytometry (A-60 Micro). Platelet-rich thrombus formation will be measured using whole blood perfusion system. The study will determine the antiplatelet effect of prostacyclin analogues and compare different prostacyclin analogues head-to-head to identify the best drugs to use in case of thrombosis or bleeding.

Official Title
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Platelet Reactivity and Treatment With Prostacyclin Analogues in Pulmonary Arterial Hypertension

Conditions
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Pulmonary Hypertension

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent to participate in the study Pulmonary arterial hypertension confirmed with right heart catheterization Treatment with prostacyclin analogues (epoprostenol, treprostinil, iloprost) - study group Treatment with endothelin receptor antagonists and phosphodiesterase type 5 inhibitors - control group Exclusion Criteria: Known coagulopathy Active pathological bleeding Known history of bleeding disorder Severe thrombocytopenia (platelet count < 50,000/μL ) Need for antiplatelet therapy with acetylsalicylic acid or P2Y12 antagonists Severe chronic renal failure (estimated glomerular filtration rate < 30 mL/min) Severe liver insufficiency (Child-Pugh class C) Known pregnancy, breast-feeding, or intention to become pregnant during the study period Study drug intolerance Participation in any previous study with prostacyclin analogues

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 99 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Study group<br>Patients with pulmonary arterial hypertension treated with prostacyclin analogues on top of ERA or PDE-5i. | |
| Control group<br>Patients with pulmonary arterial hypertension treated with ERA or PDE-5i only. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Platelet reactivity | Difference in platelet reactivity between patients treated with prostacyclin analogues and treated with ERA and/ or PDE5-i, assessed using impedance aggregometry | July 5, 2017 - November 30, 2019 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Concentration of extracellular vesicles from platelets, leukocytes and endothelial cells | Differences in concentration of extracellular vesicles from platelets, leukocytes and endothelial cells between patients treated with prostacyclin analogues and treated with ERA and/ or PDE5i, assessed using flow cytometry | July 5, 2017 - November 30, 2019 | 
| Platelet-rich thrombus formation parameters | Differences in platelet-rich thrombus formation parameters between patients treated with prostacyclin analogues and treated with ERA and/ or PDE5i, assessed using whole-blood flow-chamber perfusion system | July 5, 2017 - November 30, 2019 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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prostacyclin analogues, pulmonary arterial hypertension, platelet reactivity, extracellular vesicles, thrombus formation