A daily treatment regimen of rivaroxaban and aspirin was associated with a 24 percent decreased risk of major adverse cardiovascular events (MACE) compared to aspirin-only therapy in patients with stable atherosclerotic vascular disease, according to new research published in The New England Journal of Medicine. However, patients treated with rivaroxaban plus aspirin showed a 70 percent greater risk of major bleeding events than those treated with aspirin alone.

Researchers designed the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) trial to study the effectiveness of three different treatment options in patients with stable cardiovascular disease: rivaroxaban (2.5 mg twice daily) plus aspirin (100 mg once daily), rivaroxaban monotherapy (5 mg twice daily) and aspirin monotherapy (100 mg once daily). Xarelto is the brand name for rivaroxaban.

The randomized trial enrolled 27,395 patients across 602 centers in 33 countries. The study population was 78 percent men and had a mean age of 68.2 years.

Researchers tracked MACE—defined as a composite of cardiovascular death, stroke or myocardial infarction—and major bleeding events for an average of 23 months.

Rivaroxaban, whether taken alone or combined with aspirin, was associated with more major bleeding events than aspirin monotherapy. Patients receiving just rivaroxaban did not show a significant difference of MACE when compared to aspirin-only treatment, but the combination of the treatments resulted in a significant reduction in MACE (4.1 percent versus 5.4 percent in the aspirin-only group).

The rate of net-clinical-benefit outcome, which included MACE, fatal bleeding and symptomatic bleeding into a critical organ, was 20 percent lower with the rivaroxaban/aspirin regimen than aspirin monotherapy.

"The results of COMPASS represent a true breakthrough in CAD (coronary artery disease) and PAD (peripheral artery disease), as they confirm the combination regimen of Xarelto and aspirin is highly effective and well-tolerated in preventing the devastating and irreversible CV events that often occur in these patients," COMPASS lead investigator Dr. John Eikelboom, of McMaster University, Hamilton Health Sciences in Hamilton, Ontario, said in a statement.

"In addition to achieving a positive balance of efficacy and safety, we observed a considerable reduction in stroke and CV death, which could have a profound effect on how physicians manage patients with stable CAD and PAD."