A Study of Aspirin and Clopidogrel in Patients With Idiopathic Pulmonary Arterial Hypertension

A Double-Blind, Placebo-Controlled, Three Treatment Cross-Over Study of Aspirin and Clopidogrel in Patients With Idiopathic Pulmonary Arterial Hypertension

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00105209

Enrollment

Registered

2005-03-10

Start date

2002-04-30

Completion date

2003-12-31

Last updated

2005-06-24

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Hypertension, Pulmonary

Keywords

Platelets

Brief summary

Rationale: Idiopathic pulmonary arterial hypertension (IPAH) is characterized by in situ thrombosis and increased thromboxane A2 (Tx-M) synthesis. While both may be attributable to abnormal platelet function, there are no studies of anti-platelet therapy in IPAH. Objectives: The purpose of this study is to assess the effects of aspirin (ASA) and clopidogrel on platelet function and eicosanoid metabolism in patients with IPAH.

Detailed description

This is a randomized, double-blind, placebo-controlled crossover study of aspirin 81 mg once daily and clopidogrel 75 mg once daily. Platelet function is assessed with plasma P-selectin levels and aggregometry after exposure to adenosine diphosphate, arachidonic acid, and collagen. We will assess serum levels of thromboxane B2 and urinary metabolites of thromboxane A2 and prostaglandin I2 (Tx-M and PGI-M, respectively).

Interventions

DRUGAspirin

DRUGclopidogrel

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

DOUBLE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Diagnosis of IPAH * ≥ 18 years of age * NYHA functional class I, II, or III * Clinical stability (i.e., without change in pulmonary arterial hypertension medical regimen within one month prior to enrollment).

Exclusion criteria

* Other forms of PAH * A contraindication to ASA or clopidogrel * Thrombocytopenia (defined as platelet count ≤ 75,000) * History of intracranial hemorrhage or chronic thromboembolic disease * Renal failure * Inability or unwillingness to avoid non-steroidal anti-inflammatory agents, ASA, or warfarin use for the duration of the trial

Design outcomes

Primary

Measure	Time frame
Plasma P-selectin level	—
Aggregometry	—
Serum thromboxane B2	—
Urinary Tx-M	—
Urinary prostaglandin I2 (PGI-M)	—

Secondary

Measure	Time frame
Adverse events	—

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026