Combo therapy works better than only aspirin for heart diseases

People with vascular disease are less likely to suffer further heart complications if they are taking a combination of two drugs - rivaroxaban and aspirin - rather than aspirin alone, according to a recent study.

The study, called COMPASS and led by the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences (HHS) in Hamilton, Canada, looked at 27,400 people with stable coronary or peripheral artery disease from 33 countries worldwide.

The results showed that the combination of 2.5 mg of rivaroxaban twice daily plus 100 mg of aspirin once daily was significantly better than only aspirin or only rivaroxaban in preventing heart attacks, strokes and death.

Rivaroxaban, often known by the brand name Xarelto, is an anticoagulant, aspirin is an antiplatelet drug, and both are blood thinners.

The clear result of this clinical study - that the combination reduced strokes, heart attacks and cardiovascular death by practically 25 per cent compared to either drug alone in both patients with stable coronary or peripheral artery disease - caused the clinical trial to be stopped early, after 23 months, in February 2017.

The researchers report that the drug combination does increase the chance of a major bleeding. These bleeds were mainly gastroenterological, and not in critical organs such as the brain nor fatal.

Co-principal investigator John Eikelboom and his team compared rivaroxaban at doses of 2.5 mg twice-daily combined with 100 mg of aspirin once-daily to rivaroxaban 5 mg twice-daily or to aspirin 100 mg once-daily. In the randomized clinical trial, patients were seen at one and six months, and then every six months.

They found the drug combination reduces cardiovascular outcomes, increases bleeding and improves survival in stable coronary or peripheral artery disease.

"Efforts to improve aspirin have focused primarily on combining aspirin with another antiplatelet drug or replacing aspirin with another antiplatelet drug, but this has had only limited success," said Eikelboom.

A second paper from the same study, which is forthcoming in The Lancet, showed that the same drug combination is superior to aspirin for the risk of losing limbs or severe limb ischemia (limitation of blood flow to a limb), as well as decreasing cardiovascular events, among patients with peripheral artery disease (PAD).

The study looked at 7,470 patients with PAD who took part in the COMPASS study, and found the combination reduced heart attacks, stroke or cardiovascular death by 28 per cent and damage to limbs by 46 percent.

Sonia Anand, who led the PAD component of the COMPASS trial, said: "This is an important advance for patients with peripheral artery disease. Until now we have only had aspirin for these patients, which is only modestly effective. To now have a therapy that both reduce major adverse cardiovascular events and major adverse limb events by one-third is going to be a great benefit for these high-risk patients."

The results will be published in the New England Journal of Medicine.