Multicenter Trial of Antithrombotic Strategies in Acute Coronary Syndrome With Coronary Artery Ectasia (OVER-TIME II)

April 6, 2026 updated by: Diego Araiza-Garaygordobil, Instituto Nacional de Cardiologia Ignacio Chavez

Dual Antiplatelet Therapy Versus Antiplatelet Monotherapy Plus Anticoagulation in Patients With Acute Coronary Syndrome and Coronary Artery Ectasia: A Multicenter Randomized Clinical Trial

Coronary artery ectasia (CAE) is a condition in which a coronary artery becomes abnormally dilated, measuring at least 50% larger than the adjacent normal segment. Although relatively uncommon, CAE is clinically important because it can lead to abnormal blood flow and increase the risk of blood clot formation. Patients with CAE are at higher risk of angina, myocardial infarction, and complications during coronary interventions. Despite these risks, the optimal antithrombotic treatment for patients with acute coronary syndrome (ACS) and CAE remains uncertain.

Dual antiplatelet therapy (aspirin plus clopidogrel) is currently the most commonly used treatment. However, the abnormal blood flow patterns observed in CAE may promote clot formation through mechanisms that could potentially be better addressed with anticoagulant therapy.

The OVER-TIME II trial is a multicenter randomized clinical trial designed to compare two antithrombotic strategies in patients with ACS and CAE: standard dual antiplatelet therapy versus antiplatelet monotherapy combined with anticoagulation. The study aims to determine whether the addition of anticoagulation reduces major cardiovascular events without significantly increasing bleeding risk.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Coronary artery ectasia (CAE) is defined as an abnormal dilatation of a coronary artery segment measuring at least 50% greater than the diameter of the adjacent normal segment. Although relatively uncommon, CAE represents a clinically relevant phenotype of coronary artery disease. Its reported prevalence ranges from 0.3% to 4.9% worldwide; however, higher frequencies have been described in certain populations. At the National Institute of Cardiology "Ignacio Chávez" (INCICh) in Mexico, a prevalence of approximately 10.3% has been documented among patients presenting with ST-segment elevation myocardial infarction (STEMI), highlighting the importance of studying this condition in the Mexican population.

The pathophysiology of CAE involves abnormal coronary blood flow dynamics, including turbulent flow and blood stasis within dilated segments. These changes may promote thrombus formation through multiple mechanisms, including platelet activation, local inflammatory processes, endothelial dysfunction, and potential prothrombotic states. Genetic susceptibility and molecular pathways related to vascular remodeling may also contribute to the development and progression of the disease. Clinically, patients with CAE have been associated with a higher risk of angina, myocardial infarction, distal embolization, and complications during percutaneous coronary intervention.

Despite its clinical significance, the optimal antithrombotic strategy in patients with acute coronary syndrome (ACS) and CAE remains uncertain. Dual antiplatelet therapy (DAPT), typically consisting of aspirin and a P2Y12 inhibitor, is the most commonly used treatment. However, given the propensity for thrombus formation related to abnormal flow conditions in ectatic coronary segments, anticoagulation has been proposed as a potentially beneficial therapeutic strategy.

The exploratory OVERTIME trial conducted at INCICh compared an antithrombotic regimen consisting of antiplatelet monotherapy plus a direct oral anticoagulant (clopidogrel 75 mg plus rivaroxaban 15 mg daily) with standard dual antiplatelet therapy (aspirin 100 mg plus clopidogrel 75 mg daily) in patients with ACS and CAE. Although limited by sample size, the study demonstrated a numerical reduction in major adverse cardiovascular events and a shorter endogenous fibrinolysis time among patients receiving the combination of antiplatelet therapy and anticoagulation, without a significant increase in bleeding events.

These findings support the hypothesis that anticoagulation combined with antiplatelet therapy may improve clinical outcomes in this high-risk population. However, larger randomized studies are needed to confirm these results and provide definitive evidence to guide clinical management.

The OVER-TIME II trial is a multicenter, randomized clinical trial designed to compare two antithrombotic strategies in patients with ACS and angiographically confirmed CAE: (1) standard dual antiplatelet therapy and (2) antiplatelet monotherapy combined with oral anticoagulation. The primary objective is to evaluate whether the addition of anticoagulation reduces major cardiovascular events without significantly increasing bleeding risk.

In addition to the clinical trial component, the study will incorporate a translational research arm. Peripheral blood samples will be collected to investigate genetic variants and DNA and RNA expression profiles that may be associated with susceptibility to CAE, disease progression, and differential response to antithrombotic therapy. These analyses aim to improve the understanding of the biological mechanisms underlying CAE and to identify potential biomarkers that could inform future personalized treatment strategies.

Study Type

Interventional

Enrollment (Estimated)

326

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Mexico
    • Tlalpan
      • Mexico City, Tlalpan, Mexico, 14080
        • Recruiting
        • Instituto Nacional de Cardiología "Ignacio Chávez"
        • Contact:
        • Principal Investigator:
          • Diego Araiza Garaygordobil, MD MSc PhD
        • Sub-Investigator:
          • Edith Adame Avilés, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18 to 80 years, of either sex, hospitalized with acute coronary syndrome (ACS) with or without ST-segment elevation.
  • Recent ACS within 7 days prior to enrollment, defined by all of the following:
  • Clinical presentation consistent with acute coronary syndrome.
  • Elevated high-sensitivity cardiac troponin above the 99th percentile.
  • Presence or absence of persistent ST-segment elevation.
  • Coronary artery ectasia in the culprit coronary artery, defined by all of the following:
  • The presence of ectasia will be determined by agreement of two expert interventional cardiologists, and will be confirmed by quantitative coronary angiography (QCA).
  • Identification of a culprit artery consistent with the electrocardiographic territory involved (in cases with ST-segment elevation) or with angiographic features suggestive of an atherothrombotic event, such as the presence of thrombus or reduced coronary flow.
  • Hospital admission lasting more than 24 hours.
  • Management with either percutaneous coronary intervention or medical therapy, as determined by the treating medical team. Intracoronary interventions such as stent implantation, balloon angioplasty, or thrombus aspiration are permitted.
  • Ability and willingness to provide written informed consent and to participate in the study.

Exclusion Criteria:

  • Pregnant women.
  • Current indication for temporary or long-term anticoagulation therapy at the time of enrollment.
  • Severe chronic kidney disease, defined as KDIGO stage G4 or higher (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m²).
  • Estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m² at hospital discharge.
  • History of major bleeding, active bleeding, or high bleeding risk, including but not limited to gastrointestinal bleeding, intracranial hemorrhage, or other conditions considered by the treating physician to confer a high risk of bleeding.
  • Advanced heart failure, defined as left ventricular ejection fraction (LVEF) <30% plus at least one of the following:
  • More than two hospitalizations or unplanned emergency department visits for heart failure in the past year, or
  • NYHA functional class III or IV symptoms despite optimal medical therapy at enrollment or within the previous 3 months.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Dual Antiplatelet Therapy
Participants receive standard dual antiplatelet therapy consisting of aspirin 100 mg once daily plus clopidogrel 75 mg once daily
Drug: Aspirin 100 mg
Participants receive aspirin 100 mg once daily
Drug: Clopidogrel 75 mg
Participants receive clopidogrel 75 mg once daily
Experimental: Antiplatelet Monotherapy Plus Oral Anticoagulation
Participants receive antiplatelet monotherapy with clopidogrel 75 mg once daily plus oral anticoagulation using rivaroxaban 15 mg once daily
Drug: Clopidogrel 75 mg
Participants receive clopidogrel 75 mg once daily
Drug: Rivaroxaban 15 mg
Participants receive oral anticoagulation using rivaroxaban 15 mg once daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time to First Major Adverse Cardiovascular Event (MACE)
Time Frame: 12 months
Time to first occurrence of the composite of cardiovascular death, non-fatal myocardial infarction, or repeat coronary revascularization in patients with coronary artery ectasia following acute coronary syndrome, according to the assigned antithrombotic treatment strategy (dual antiplatelet therapy versus clopidogrel plus rivaroxaban).
12 months
Time to First Bleeding Event According to the BARC Classification
Time Frame: 12 months
Time to first occurrence of a composite of major or minor bleeding events defined according to the Bleeding Academic Research Consortium (BARC) classification in patients with coronary artery ectasia following acute coronary syndrome, according to the assigned antithrombotic treatment strategy (dual antiplatelet therapy versus clopidogrel plus rivaroxaban).
12 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Individual Components of the Major Adverse Cardiovascular Event Composite
Time Frame: 12 months
Incidence of each individual component of the primary efficacy composite endpoint (cardiovascular death, non-fatal myocardial infarction, and repeat coronary revascularization) in patients with coronary artery ectasia following acute coronary syndrome, according to the assigned antithrombotic treatment strategy.
12 months
Individual Bleeding Events According to the BARC Classification
Time Frame: 12 months
Incidence of individual bleeding events according to the Bleeding Academic Research Consortium (BARC) classification in patients with coronary artery ectasia following acute coronary syndrome, according to the assigned antithrombotic treatment strategy.
12 months

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Genetic Variants and Gene Expression Profiles Associated With Coronary Artery Ectasia and Treatment Response
Time Frame: Baseline and 12 months
Analysis of genetic variants and gene expression profiles, including DNA, RNA and circulating microRNA obtained from peripheral blood samples collected at randomization and at 12 months of follow-up. These analyses aim to identify molecular signatures associated with susceptibility to coronary artery ectasia, disease progression, and differential response to antithrombotic therapy. This exploratory analysis will be performed in an approximately 30% subset of the study population.
Baseline and 12 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Instituto Nacional de Cardiologia Ignacio Chavez

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 11, 2026

Primary Completion (Estimated)

June 1, 2029

Study Completion (Estimated)

June 1, 2029

Study Registration Dates

First Submitted

March 30, 2026

First Submitted That Met QC Criteria

March 30, 2026

First Posted (Actual)

April 6, 2026

Study Record Updates

Last Update Posted (Actual)

April 9, 2026

Last Update Submitted That Met QC Criteria

April 6, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 26-1556

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Some information might be available upon reasonable request.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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