For those with severe chest pain and heart attacks comes research showing a drug would make them far less likely to die or suffer heart-related problems so long as it’s taken with anti-clotting medicine.
While the benefit is strong, patients and their cardiologists should weigh taking the drug rivaroxaban against the increased risk of serious bleeding, often in the digestive tract.
“We’re trying to walk the tightrope of balancing efficacy with non-excessive bleeding,” said Robert Welsh, cardiac catheterization laboratory director at the Mazankowski Albert Heart Institute in Edmonton. “Those things are tough... we are trying to find that sweet spot where we can deliver safe care.”
Published online in the New England Journal of Medicine on Sunday, the study found a low dose (2.5 mg) of the drug taken twice daily with an anti-platelet cut the risk of dying of any cause by more than 30 per cent.
Though the drug is licensed for use in Canada for the prevention of venous thromboembolic events in those who had elective total hip or knee replacement surgery, doctors say they will need to carefully select which heart patients can reap its biggest benefit.
An estimated 22,161 people died in 2008-2009 of acute coronary syndrome in Canada, which occurs when a blood clot blocks a coronary artery, a condition that can lead to unstable angina or heart attacks.
Though new drugs are added to treatment protocols, Dr. Welsh said it may be worth considering whether it is time to drop others that are less efficacious.
“We’re always adding new therapies on top of what’s already been proven,” said Dr. Welsh, a study investigator, said in a telephone interview from Orlando, Fla. Sunday. “We have a new drug that’s shown very promising results and maybe some of our old drugs should be taken away.”
The double blind, randomized, placebo-controlled study tracked 15,500 patients worldwide with acute coronary syndrome. The study included 190 Canadian patients in 17 hospital sites.
In the study, all patients who left the hospital following severe chest pain from clogged arteries or a heart attack were prescribed an older blood thinner and aspirin, the current standard of care. A third of patients were given a low dose of rivaroxaban; another third were given a higher dose of 5 mg.
After about one year of taking the drug, almost 11 per cent of those on the usual medicines sustained a heart attack, heart-related death or stroke, compared to less than 9 per cent of patients on the higher or lower dose of rivaroxaban.
The lower dose proved safer. Specifically, less than 3 per cent of those taking it died of any cause during the study, compared with 4.5 per cent taking the usual medicines, which translates into a 32 percent lower risk of death with the new drug.
Put another way, to prevent one heart-related death, heart attack or stroke, 56 people would need to be treated for two years with a low dose of the new drug.
Side effects included serious bleeding that was nearly four times more common with the drug, including bleeding in the head. Bleeding that caused death, however, was no greater, according to the study sponsored by the drug's makers, Johnson & Johnson and Bayer Healthcare, and released at an American Heart Association conference in Orlando, Florida on Sunday.
Rivaroxaban is currently under review by Health Canada for two other indications: stroke prevention in patients with atrial fibrillation (the most common abnormal rhythm of the heart) and treatment of deep venous thrombosis.
An application seeking approval from Health Canada for this new use will be made in Canada, after the United States and Europe file for approval with their respective regulatory agencies at the end of year, Shurjeel Choudhri, senior vice-president and head of medical and scientific affairs for Bayer Inc., said in a telephone interview.