Millions of American heart patients take warfarin — for decades a cheap, but often tricky-to-manage mainstay blood thinner.
Now, new research shows that when it is well-managed, warfarin treatment appears safe for people with atrial fibrillation, a common heart rhythm disorder.
“Well-managed warfarin treatment is a valid alternative in patients with atrial fibrillation who require anticoagulant treatments, with relatively low complication rates and low all-cause [death rates],” concludes a team led by Dr. Fredrik Bjorck of Umea University in Sweden.
The findings come in the context of newer, but much pricier, blood thinners — drugs such as Eliquis, Pradaxa and Xarelto. One expert who reviewed the new study said he would still opt for these medications over warfarin, because they are so much easier to manage.
“In my opinion, the benefits of improved patient compliance, ease of management and safety with [these drugs] as compared to warfarin, outweighs the cost issue and they are my first choice when choosing anticoagulation for atrial fibrillation patients,” said Dr. Nicholas Skipitaris. He directs cardiac electrophysiology at Lenox Hill Hospital in New York City.
The new findings were published online April 20 in the journal JAMA Cardiology.
The study authors explained that atrial fibrillation raises a person’s risk of stroke. And, warfarin therapy reduces the risk of stroke by 64 percent and the risk of death from any cause by 26 percent, the researchers said.
However, like any blood thinner, warfarin does boost the risk of major bleeding, including bleeding inside the skull (intracranial bleeding). So doctors sometimes have trouble managing the drug — balancing its anti-clotting powers against the risk for bleeding.
In the study, Bjorck’s team tracked data from more than 40,000 people in Sweden with atrial fibrillation who took warfarin.
The study found that the annual rate of intracranial bleeding was 0.44 percent and the annual rate of death from all causes was about 2.2 percent.
Among patients who also took another blood thinner, aspirin, the annual rate of any major bleeding was just over 3 percent and the annual rate of blood clots was close to 5 percent, the team noted.
The researchers also found that patients with kidney failure were at higher risk for intracranial bleeding compared to those with healthier kidneys.
But Skipitaris believes that the Swedish population study can’t show the whole picture.
“The problem is that in the ‘real world,’ we cannot predict which patients on warfarin will do well with the drug, and it remains difficult to adjust reliably,” he said.
Warfarin (also known as Coumadin), “requires frequent monitoring and has many interactions with diet and other medications,” Skipitaris said. On the other hand, the newer blood thinners, while more expensive, “do not have these requirements or restrictions,” he added.
The U.S. National Heart, Lung, and Blood Institute has more about atrial fibrillation.