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NCT Number: NCT07709780

Apixaban Versus Warfarin for Left Ventricular Thrombus

Left ventricular thrombus is a blood clot that forms in the left ventricle and is associated with risk of systemic embolism and ischemic stroke. Warfarin has historically been used for anticoagulation in this condition, but it requires frequent international normalized ratio monitoring and is affected by dietary and drug interactions. Apixaban is a direct oral factor Xa inhibitor with fixed dosing and no routine anticoagulation monitoring requirement, and it is increasingly used in clinical practice for left ventricular thrombus, although definitive randomized evidence remains limited.

This randomized, noninferiority trial will compare apixaban with warfarin for treatment of left ventricular thrombus. Eligible adults with recently confirmed left ventricular thrombus will be randomized 1:1 to apixaban or warfarin. The primary endpoint is complete left ventricular thrombus resolution at 3 months assessed by cardiac magnetic resonance imaging. Participants will be followed through 12 months for thrombus-related, bleeding, cardiovascular, and mortality outcomes.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

Banner University Medical Center - Tucson

Tucson, Arizona, 85724, United States

Location status: Recruiting

Location contact

Alane Blythe C Dy, PhD, MSPH

PRINCIPAL_INVESTIGATOR

Song Peng Ang, MD

PRINCIPAL_INVESTIGATOR

Tushar Acharya, MD, MPH

PRINCIPAL_INVESTIGATOR

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age ≥18 years
  • LV thrombus confirmed within 14 days prior to randomization by CMR or contrast TTE or cardiac CT; baseline CMR required pre-randomization (or ≤7 days post-randomization if clinically unavoidable)
  • Candidate for oral anticoagulation for ≥3 months
  • Able to provide informed consent.

Exclusion criteria

  • Absolute indication for VKA (mechanical valve, moderate-severe rheumatic MS and antiphospholipid syndrome) or clear preference or contraindication for one of the study drugs precluding randomization (see below)
  • Antiphospholipid syndrome
  • Estimated CrCl <15 mL/min or dialysis
  • Severe hepatic impairment (ICD-10: K70.40, K70.41, K71.10, K71.11, K72.00, K72.01, K72.10, K72.11, K72.90, K72.91)
  • Active clinically significant bleeding
  • Platelets <50,000/µL
  • Pregnancy or lactation; women of childbearing potential unwilling to use contraception
  • Life expectancy <1 year or other conditions compromising follow-up

Additional contraindications to use of warfarin or apixaban. This includes, but is not limited to:

  • Active pathological bleeding, major bleeding diathesis, or known blood dyscrasia
  • Recent or planned surgery involving the central nervous system or eye, traumatic surgery with large open surfaces, or procedures (spinal/epidural puncture or major regional block anesthesia) where bleeding cannot be safely controlled.
  • Conditions associated with high risk of bleeding such as threatened abortion, eclampsia, severe preeclampsia, or malignant/uncontrolled hypertension.
  • History of severe hypersensitivity or allergy to warfarin or apixaban.
  • Ongoing treatment with a combined P-gp and strong CYP3A4 inhibitor or inducer that cannot be safely discontinued or substituted. Examples include strong combined inhibitors such as ketoconazole, itraconazole, ritonavir or posiconazole, and strong combined inducers such as rifampin, carbamazepine, phenytoin, and St. John's wort.

Treatment and study plan

Apixaban

Drug

Apixaban 5 mg orally twice daily

Warfarin

Drug

Warfarin will be prescribed with dose adjustment to maintain INR 2.0-3.0.

Primary outcomes

  1. Complete Left Ventricular Thrombus Resolution at 3 Months

    Time frame: 3 months after randomization

    Proportion of participants with complete resolution of left ventricular thrombus at 3 months, assessed by cardiac magnetic resonance imaging. The primary noninferiority comparison will use the absolute between-group difference in the proportion of participants with complete thrombus resolution, apixaban minus warfarin.

Secondary outcomes

  1. Major Bleeding

    Time frame: 6 months

    Proportion of participants with major bleeding defined as BARC type 3 or 5 bleeding.

  2. Change in LV Thrombus Volume

    Time frame: Baseline to 3, 6, or 12 months

    Change in thrombus volume assessed by CMR

  3. Left Ventricular Remodeling

    Time frame: Baseline to 3, 6,12 months

    Change in left ventricular ejection fraction and left ventricular volumes on follow-up imaging.

  4. Recurrent LV Thrombus

    Time frame: 12 months

    Proportion of participants with recurrent LV thrombus after documented resolution.

  5. Ischemic Stroke

    Time frame: 12 months

    Proportion of participants with ischemic stroke.

  6. Systemic embolism

    Time frame: 12 months

    Proportion of participants with systemic embolism

  7. Cardiovascular Mortality

    Time frame: 12 months

    Proportion of participants with cardiovascular death.

  8. All-Cause Mortality

    Time frame: 12 months

    Proportion of participants with death from any cause.

Study contacts

Contact information is provided by the study sponsor or research team.

Tushar Acharya, MD, MPH

CONTACT

[email protected]

520-626-0968

Sponsors and collaborators

Lead sponsor

University of Arizona

Other

Registry information

Official study title

Apixaban vs. Warfarin in Left Ventricular Thrombus: A Randomized, Noninferiority Trial

Acronym: APEX

Important dates

Study start
2026
Primary completion
2028
Study completion
2029
First posted
Jul 17, 2026
Registry last updated
Jul 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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