Nav: Home

New study finds antithrombotic therapy has no benefit for low-risk atrial fibrillation patients

March 17, 2017

Findings from a large, community-based study show that antithrombotic therapy doesn't decrease low-risk atrial fibrillation patients' risk of suffering a stroke within five years. In fact, researchers found that low-risk patients fared better without any antithrombotic therapy.

The new findings from researchers at the Intermountain Medical Center Heart Institute in Salt Lake City will be presented on March 17 at the American College of Cardiology's 66th Annual Scientific Session in Washington, D.C.

Antithrombotic agents are drugs that reduce the formation of blood clots. Antithrombotics can be used therapeutically for prevention or treatment of a dangerous blood clots.

The news findings contradict some current standards. For instance, the European Cardiology Society advocates oral anticoagulation therapy for patients with stroke risk factors as defined by a CHA2DS2 VASc score of 1 or more for men and 2 or more for women.

However, the Intermountain Medical Center Heart Institute study found that low-risk patients -- with a CHADS2 score of 0-1 or CHA2DS2 VASc score of 0-2 -- who received antithrombotic therapy experienced higher rates of stroke and significant bleeding.

CHADS2 is an acronym that helps clinicians recall major stroke risk factors, assigning one point for each letter: "C" for congestive heart failure, "H" for high blood pressure, "A" for age 75 or older and "D" for diabetes. "S" stands for stroke and the "2" denotes an extra point is assigned for a previous stroke. CHA2DS2-VASc builds on CHADS2, adding points for being female, being between the ages 65-75 and having vascular disease.

Intermountain Medical Center Heart Institute researcher Victoria Jacobs, PhD, NP, says the use of oral anticoagulation or antiplatelet therapies is controversial in the medical community.

"There is still no consensus regarding the initiation of these therapies in low-stroke risk patients, but findings from our study add important insight into this issue," she said.

The study involved 56,723 patients diagnosed with atrial fibrillation and a CHADS2 scores of 0-1 and CHADS2 VASc scores of 0-2. Patients were divided into groups receiving aspirin, Clopidogrel and Warfarin.

Follow-up after five years showed that 4.6 percent of aspirin-prescribed patients suffered a stroke versus 2.3 percent of those who weren't on it; 17.6 percent of those using aspirin experienced significant bleeding versus 11.5 percent not on it.

Of warfarin-prescribed patients, 5.7 percent suffered a stroke after five years versus 2.6 percent of those not on it; 22.3 percent of warfarin patients experienced significant bleeding versus 12.3 percent not on it.

The study concludes that anticoagulation or antiplatelet therapies don't lower stroke rates in low-risk patients, but rather increase their risk of significant bleeding and death.

"We need more studies enrolling low-risk stroke patients, particularly in randomized, controlled trials to guide providers to optimal therapies for these patients," Jacobs said.
-end-
Anjani Golive, MD, was the principal investigator on the Intermountain Medical Center Heart Institute study. Other researchers included Heidi May, PhD; Tami Bair, RN; Brian Crandall, MD; Michael J. Cutler, DO; John Day, MD, Charles Mallender, MD; Jeffrey S. Osborn, MD; Jonathan Weiss, MD; and T. Jared Bunch, MD.

Intermountain Medical Center

Related Stroke Articles:

Retraining the brain to see after stroke
A new study out today in Neurology, provides the first evidence that rigorous visual training restores rudimentary sight in patients who went partially blind after suffering a stroke, while patients who did not train continued to get progressively worse.
Catheter ablations reduce risks of stroke in heart patients with stroke history, study finds
Atrial fibrillation patients with a prior history of stroke who undergo catheter ablation to treat the abnormal heart rhythm lower their long-term risk of a recurrent stroke by 50 percent, according to new research from the Intermountain Medical Center Heart Institute.
Imaging stroke risk in 4-D
A new MRI technique developed at Northwestern University detects blood flow velocity to identify who is most at risk for stroke, so they can be treated accordingly.
Biomarkers may help better predict who will have a stroke
People with high levels of four biomarkers in the blood may be more likely to develop a stroke than people with low levels of the biomarkers, according to a study published in the Aug.
Pre-stroke risk factors influence long-term future stroke, dementia risk
If you had heart disease risk factors, such as high blood pressure, before your first stoke, your risk of suffering subsequent strokes and dementia long after your initial stroke may be higher.
Intervention methods of stroke need to focus on prevention for blacks to reduce stroke mortality
Blacks are four times more likely than their white counterparts to die from stroke at age 45.
Study shows area undamaged by stroke remains so, regardless of time stroke is left untreated
A study led by Achala Vagal, M.D., associate professor at the University of Cincinnati College of Medicine and a UC Health radiologist, looked at a group of untreated acute stroke patients and found that there was no evidence of time dependence on damage outcomes for the penumbra, or tissue that is at risk of progressing to dead tissue but is still salvageable if blood flow is returned in a stroke, but rather an association with collateral flow -- or rerouting of blood through clear vessels.
Immediate aspirin after mini-stroke substantially reduces risk of major stroke
Using aspirin urgently could substantially reduce the risk of major strokes in patients who have minor 'warning' events.
SAGE launches the European Stroke Journal with the European Stroke Organisation
SAGE, a world leading independent and academic publisher, is delighted to announce the launch of the European Stroke Journal, the flagship journal of the European Stroke Organisation.
The S-stroke or I-stroke?
The year 2016 is an Olympic year. Developments in high-performance swimwear for swimming continue to advance, along with other areas of scientific research.

Related Stroke Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Digital Manipulation
Technology has reshaped our lives in amazing ways. But at what cost? This hour, TED speakers reveal how what we see, read, believe — even how we vote — can be manipulated by the technology we use. Guests include journalist Carole Cadwalladr, consumer advocate Finn Myrstad, writer and marketing professor Scott Galloway, behavioral designer Nir Eyal, and computer graphics researcher Doug Roble.
Now Playing: Science for the People

#530 Why Aren't We Dead Yet?
We only notice our immune systems when they aren't working properly, or when they're under attack. How does our immune system understand what bits of us are us, and what bits are invading germs and viruses? How different are human immune systems from the immune systems of other creatures? And is the immune system so often the target of sketchy medical advice? Those questions and more, this week in our conversation with author Idan Ben-Barak about his book "Why Aren't We Dead Yet?: The Survivor’s Guide to the Immune System".