Recruiting

Antithrombotic Treatment

Sponsor:

McMaster University

Code:

NCT05646394

Conditions

Antiphospholipid Syndrome

Arterial Thrombosis

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Dual antiplatelet therapy

Combined antithrombotic therapy

Vitamin K antagonist standard intensity

Vitamin K antagonist high intensity

Study Details

Brief summary:

The goal of this registry is to gather more information on the efficacy and safety of various antithrombotic regimens. The registry collects data on patients with antiphospholipid syndrome and an arterial event within the past 12 months, on treatment with either A) a VKA with therapeutic range, INR 2.0-3.0 plus low-dose aspirin (75-100 mg daily), B) a VKA alone with therapeutic range, INR 2.0-3.0, C) a VKA with therapeutic range, INR 3.0-4.0, or D) with a dual antiplatelet regimen. The follow-up is 2 years.

Conditions

Antiphospholipid Syndrome

Arterial Thrombosis

Study ID

NCT05646394

Start date

Jul 1, 2022

Status verified date

Nov, 2025

Completion date

Dec 31, 2029

Anticipated

Primary completion date

Jul 31, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Patients of at least 18 years of age with confirmed antiphospholipid syndrome according to Sydney criteria and with first or recurrent arterial thrombotic manifestation, including those with asymptomatic brain infarcts on diagnostic imaging.
2. Treatment with either A) a vitamin K antagonist (VKA) with therapeutic range, international normalized ratio (INR) 2.0-3.0 plus low-dose aspirin (75-100 mg daily), B) a VKA alone with therapeutic range, INR 2.0-3.0 or C) VKA with therapeutic range, INR 3.0-4.0, or D) with a dual antiplatelet regimen, if considered appropriate by the treating physician.
3. Signed informed consent obtained (in jurisdictions where required).

Exclusion Criteria:

1. Inability to follow the patient due to geographical or other reasons.
2. Patients with documented poor compliance.
3. Bleeding risk that in the opinion of the treating physician makes combination antithrombotic therapy unsafe.
4. Pregnancy or planned pregnancy.
5. Venous thrombotic event diagnosed after the last arterial event.

Study Design

Enrollment

150 participants

Anticipated

Interventions and Outcome Measures

Interventions

Dual antiplatelet therapy

Aspirin plus any of clopidogrel, ticagrelor or prasugrel

Combined antithrombotic therapy

Combination of a vitamin K antagonist, such as warfarin, acenocoumarol, phenprocoumon, phenindione etc, with low-dose aspirin.

Vitamin K antagonist standard intensity

vitamin K antagonist, such as warfarin, acenocoumarol, phenprocoumon, phenindione etc, with therapeutic range, international normalized ratio 2.0-3.0

Vitamin K antagonist high intensity

vitamin K antagonist, such as warfarin, acenocoumarol, phenprocoumon, phenindione etc, with therapeutic range, international normalized ratio 3.0-4.0

Primary outcome measure

  • Number of Participants with thromboembolism verified by diagnostic imaging, electrocardiogram or troponin rise [ Time Frame: 2 years ]
  • Number of Participants with major hemorrhage fulfilling at least one of the International Society on Thrombosis and Haemostasis criteria [ Time Frame: 2 years ]

Central Contacts and Locations

Central contacts

Sam Schulman, MD, PhD

+19055270271schulms@mcmaster.ca

Hannah Cohen, MD, FRCP

+442034477368hannah.cohen@ucl.ac.uk

Locations

McMaster University

Recruiting

Hamilton, Ontario, Canada, L9H 7M1

Contacts

Sam Schulman

9059796437schulms@mcmaster.ca

More Information

Sponsor

McMaster University

Last update posted

Dec 9, 2025

Last verified

Nov, 2025

Keywords

  • anticoagulation
  • vitamin K antagonist
  • antiaggregant
  • stroke
  • myocardial infarction
  • hemorrhage

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by McMaster University on 2025-12-09.