ACC 2025: Rivaroxaban Comparable to Warfarin in Left Ventricular Blood Clots

New data presented at the American College of Cardiology 2025 Scientific Session demonstrate that at 3 months of follow-up, patients hospitalized for a serious heart attack who were treated with rivaroxaban (Xarelto; Johnson & Johnson) for a blood clot in the left ventricle (LV) did as well as similar patients treated with warfarin (Jantoven; Upsher-Smith).¹

LV thrombus following a heart attack is considered a serious complication | Image credit: peterschreiber.media | stock.adobe.com

LV thrombus following a heart attack is considered a serious complication due to the risk that the clot will travel to the brain and cause a stroke or systemic embolism, as well as the risk that the clot will travel to the heart, kidneys, lungs, liver, spleen, or limbs.² Although the incidence of LV thrombus following acute myocardial infarction has declined in recent decades thanks to advancements in reperfusion and antithrombotic pharmacotherapies, management of this condition remains challenging because of insufficient clinical evidence from randomized trials.³

Warfarin remains the standard treatment for LV thrombus, but patients receiving this treatment require frequent blood tests to verify that the time it takes for their blood to clot remains in a therapeutic range (international normalized ratio of 2-3). Many other therapies and foods can interact with warfarin, further increasing the patient’s risk for ischemic and bleeding complications.^1,2

Unlike warfarin, rivaroxaban is an oral factor Xa inhibitor, which has more predictable blood-thinning effects. Patients taking rivaroxaban do not need regular blood tests, and rivaroxaban is less likely to interact with foods.⁴

In the RIVAWAR trial, investigators aimed to compare the efficacy of rivaroxaban with warfarin in post-heart attack patients who developed LV thrombus. The study enrolled 261 patients, approximately 80% of whom were men with an average age of 55 years. ST-segment elevation myocardial infarction (STEMI) occurs more commonly in men, and researchers noted that the patients’ relatively young average age reflects the high burden of acute coronary syndrome in Pakistan, where the study took place.²

Approximately 90% of patients had experienced a STEMI, in which one of the primary arteries carrying blood to the heart becomes completely blocked. Approximately 94% had a condition in which less than half of the blood in the LV is pumped out with each heartbeat, and about 85% were treated with coronary angioplasty.^1,2

Participants were randomly assigned to treatment with either rivaroxaban or warfarin for 3 months. The study’s primary end point was complete dissolution of the blood clot in the LV on an echocardiogram at 1 month and 3 months. Secondary end points were death from any cause, major bleeding, and rates of stroke.^1,2

“The efficacy and safety of rivaroxaban was similar to that of warfarin in resolving left ventricular thrombus at 3 months follow-up,” said Jehangir Ali Shah, MBBS, an associate professor at the National Institute of Cardiovascular Diseases in Karachi, Pakistan, and principal investigator for the study. “We saw complete resolution of blood clots in more than 95% of patients in both groups, with no evidence of excess deaths, ischemic stroke, or major bleeding.”

At 1 month, blood clots in the LV had fully dissolved in 20.1% of participants in the rivaroxaban group compared with 8.3% of those in the warfarin group, a statistically significant difference. At 3 months, clot dissolution was comparable in both groups (95.8% in the rivaroxaban group; 96.6% in the warfarin group). Results for all secondary end points were also comparable across groups.^1,2

“These findings support the use of rivaroxaban as a viable alternative to warfarin for the treatment of LV thrombus in post-heart attack patients,” Shah concluded. “Compared with warfarin, rivaroxaban offers predictable dosing and eliminates the need for routine blood tests to monitor clotting time.”

REFERENCES

1. Shah JA. Rivaroxaban comparable to warfarin in left ventricular blood clots. Presented at: American College of Cardiology 2025 Scientific Session. Chicago, IL; March 29-31, 2025.

2. Rivaroxaban comparable to warfarin in left ventricular blood clots. News release. American College of Cardiology. March 29, 2025. Accessed March 29, 2025.

3. Camaj A, Fuster V, Giustino G, et al. Left ventricular thrombus following acute myocardial infarction: JACC state-of-the-art review. J Am Col Cardiol. 2022;79(10):1010-1022. doi:10.1016/j.jacc.2022.01.011

4. Patel MR, Mahaffey KW, Garg J, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. 2011;365(10). doi:10.1056/NEJMoa1009638