BARCELONA – Combined treatment with a very low dosage of the anticoagulant rivaroxaban plus low-dose aspirin produced significant cuts in major adverse coronary, cerebral, and peripheral artery disease events with just a modest rise in major bleeding events in patients with stable disease in the COMPASS pivotal, randomized trial with more than 27,000 patients.
The benefits from the rivaroxaban plus aspirin regimen included a statistically significant 24% relative risk reduction in the study’s primary, combined endpoint, and a significant 18% relative risk reduction in all-cause death compared with a standard regimen of aspirin only, John W. Eikelboom, MD, said at the annual congress of the European Society of Cardiology. In addition, analysis of the net clinical benefit from treatment that took into account both the major adverse cardiovascular events prevented and major bleeding events induced, showed that the rivaroxaban-plus-aspirin regimen cut these by a statistically significant 20%, compared with aspirin alone.
Other notable benefits documented by the findings included a statistically significant 42% relative risk reduction for stroke and a statistically significant 46% relative risk reduction in the incidence of major adverse limb events among the roughly one-quarter of enrolled patients who entered the study with evidence of peripheral artery disease.
These risk reductions are similar in magnitude to the secondary-prevention benefits produced by controlling hypertension or dyslipidemia, noted Dr. Eikelboom, a researcher at McMaster University in Hamilton, Ont. “In the future, rivaroxaban will take its place among the other foundational treatments for long-term, secondary prevention,” he predicted in a video interview.
The COMPASS trial produced “unambiguous results that should change guidelines and the management of stable coronary artery disease,” commented Eugene Braunwald, MD, designated discussant for Dr. Eikelboom’s report. The results are “an important step for thrombocardiology,” said Dr. Braunwald, professor of medicine at Harvard Medical School in Boston.
Concurrently with Dr. Eikelboom’s report the results appeared in an article published online (N Engl J Med. 2017 Aug 27. doi: 10.1056/NEJMoa1709118). This publication also include an editorial by Dr. Braunwald (N Engl J Med. 2017 Aug 27. doi: 10.1056/NEJMe1710241).
The Rivaroxaban for the Prevention of Major Cardiovascular Events in Coronary or Peripheral Artery Disease (COMPASS) trial enrolled 27,395 patients with stable coronary, carotid, or peripheral artery disease, or a combination of two or more of these, at 602 centers in 33 countries. About 90% of enrolled patients had coronary artery disease and 27% had peripheral artery disease. The enrolled patients averaged 68 year old and were an average of 7 years removed from their index arterial event. Randomization assigned patients to receive 2.5 mg rivaroxaban (Xarelto) twice daily plus 100 mg aspirin daily, 5 mg rivaroxaban twice daily, or 100 mg aspirin once daily. The trial stopped early, after an average follow-up of 23 months, because of the overwhelming benefit seen for the rivaroxaban plus aspirin combination. The rivaroxaban-monotherapy arm failed to show any statistically significant benefits, compared with the aspirin-monotherapy control group.
The study’s primary endpoint – the combined rate of cardiovascular disease death, nonfatal stroke, and nonfatal MI – occurred in 4.1% of patients in the rivaroxaban-plus-aspirin group and in 5.4% of patients on aspirin alone. The rate of major bleeding events was 3.1% among patients on rivaroxaban plus aspirin and 1.9% in those who received aspirin only, a 51% relative increase among patients on the dual regimen, but the results showed no statistically significant increase in the rates of fatal bleeds, intracerebral bleeds, or bleeding in other critical organs.
Sonia Anand, MD, a colleague of Dr. Eikelboom’s at McMaster, presented a separate set of analyses that focused on the 7,470 enrolled patients who had been diagnosed at enrollment with peripheral artery disease. In this subgroup, the rivaroxaban-plus-aspirin regimen produced a statistically significant 28% relative risk reduction in the rate of the primary endpoint, compared with the aspirin control group. The dual regimen also produced a statistically significant 46% relative risk reduction in major adverse limb events and a significant 70% relative reduction in the incidence of major lower-extremity amputations, reported Dr. Anand, professor of medicine and director of the vascular medicine clinic at McMaster.
The COMPASS findings follow a 2012 published report from the ATLAS ACS 2-TIMI 51 trial showing that treatment with the same low-dose rivaroxaban regimen plus aspirin and a thienopyridine (clopidogrel or ticlopidine) reduced the same combined triple endpoint by a statistically significant 16%, compared with aspirin and a thienopyridine alone, in patients with a recent acute coronary syndrome event (N Engl J Med. 2012 Jan 5;366:9-19). Despite this evidence, the Food and Drug Administration never approved the 2.5-mg formulation of rivaroxaban, nor did it approve marketing of rivaroxaban for this acute coronary syndrome population. This decision may have been driven in part by a problem with incomplete follow-up of several of the enrolled patients.
The COMPASS results were “very consistent” with the ATLAS ACS 2-TIMI 51 results. noted Dr. Eikelboom. “I think it’s time to look at these two trials in combination,” he suggested. Availability of the 2.5-mg rivaroxaban formulation used in both trials would allow “a treatment strategy that could start early after an acute coronary syndrome event and then extend long term,” he said.
COMPASS was sponsored by Bayer, which markets rivaroxaban (Xarelto). Dr. Eikelboom has received research support from Bayer and also from Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi, Janssen, Pfizer, Portola, and Sanofi. Dr. Anand has received speaking honoraria from several drug compnies. Dr. Braunwald had no disclosures.
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