Tailoring Of Platelet Inhibition to Avoid Stent Thrombosis

TOPAS-1, A Pharmacodynamic Phase II Study of Clopidogrel P2Y12 Platelet Inhibition

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00914368

Acronym

TOPAS-1

Enrollment

450

Registered

2009-06-05

Start date

2009-01-31

Completion date

2010-03-31

Last updated

2010-04-13

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

Conditions

Acute Coronary Syndrome, Coronary Artery Disease, Heart Diseases, Myocardial Infarction, Stent Thrombosis

Keywords

Platelet Aggregation Inhibitors, Aspirin, Clopidogrel, Pathologic Processes, Disease, Therapeutic Uses, Syndrome, Hematologic Agents, Cardiovascular Diseases, Pharmacologic Actions

Brief summary

The primary objective of this study is to establish a cut off level of platelet inhibition that separates patients with or without previous stent occlusion with acute clinical onset while on aspirin and clopidogrel treatment within 6 months after coronary stenting for coronary artery disease.

Detailed description

To establish cut off levels of platelet inhibition using ADP-induced P2Y12-receptor mediated platelet aggregation using Accumetrics VerifyNow P2Y12 assay (PRU) and Vasodilator-stimulated phosphoprotein (VASP, PRI %)for patients with experienced stent occlusion with acute clinical onset and/or myocardial infarction within 6 months after coronary stenting for coronary artery disease.

Interventions

DRUGClopidogrel

Patients not already on clopidogrel treatment a loading dose of clopidogrel 600 mg followed by a maintenance dose of 75 mg once daily will be administered.

Study design

Allocation

NON_RANDOMIZED

Intervention model

PARALLEL

Primary purpose

SCREENING

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Inclusion criteria

* Provide signed written informed consent. * Male or female patients above 18 years old. * Previous PCI and coronary stenting for coronary artery disease * Previous (after coronary stenting) or current dual antiplatelet treatment (aspirin 75 mg once daily (o.d) and clopidogrel 75 mg o.d). All patients need to be on treatment with aspirin 75 mg once daily at least seven days prior to enrollment. * Experienced one of the following alternatives: * Stent thrombosis within 6 months of PCI while on dual antiplatelet treatment; OR * Experienced MI within 6 month after coronary stenting while on dual antiplatelet treatment; OR * No experience of stent thrombosis or MI for at least 6 months and until visit 1 (matched control)

Exclusion criteria

General

Design outcomes

Primary

Measure	Time frame
VerifyNow P2Y12 (PRU)	Within 6 months

Secondary

Measure	Time frame
VASP (PRI, %)	Within 6 months

Countries

Sweden

Outcome results

None listed

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