Patients living with Atrial Fibrillation, or AFib, are typically prescribed an anticoagulant – blood thinner medication – to reduce the risk of stroke. However, some patients may soon be able to discontinue the use of certain anti-clotting medications. According to a recent study published in the Nov. 8, 2025 issue of The New England Journal of Medicine, AFib patients who undergo successful catheter ablation procedures may no longer need to take certain blood thinners, if they meet certain medical requirements.
Dr. John Day – a cardiologist at the Heart Center at St. Mark’s and the physician executive of Cardiovascular Services for MountainStar Healthcare, was the first in Utah to use pulsed-field ablation technology. The technology has quickly become the "gold standard" in the treatment of AFib. Dr. Day performed the first PFA in the state in March 2024 at St. Mark’s Hospital. Dr. Day is board certified in cardiology and cardiac electrophysiology.
Dr. Day joined FOX13’s The PLACE Friday to discuss the research supported by two new clinical trials. He is one of the leading experts in the deployment of PFA technology.
“I understand why people worry about the cost, inconvenience, and potential side effects of taking blood thinners indefinitely,” Dr. Day expressed. “We are now actively ‘de-prescribing’ blood thinners in most of our successfully ablated patients.”
Pulsed-Field Ablation (PFA) to treat AFib
Ablation is one of several procedural and medical interventions used to control AFib symptoms and reduce stroke risk. Catheter ablation — a procedure that destroys faulty electrical pathways in the heart — has become a routine, first-line procedure for AFib treatment. The more traditional ablation treatment, done for years, uses either heat or cold energy to create tiny scars in an area of the heart. The catheter, or tube, is placed into blood vessels and guided to the heart. According to the Mayo Clinic, “The signals that tell the heart to beat can't pass through scar tissue so the treatment helps block faulty signals that cause AFib.”
In more recent years, Pulsed-Field Ablation, or PFA, has become more commonly used. PFA utilizes a controlled electric field to selectively ablate cardiac tissue that is causing irregular heartbeats. This treatment method has been shown to minimize the risk of damage to surrounding tissues because PFA disables cardiac cells using electricity rather than extreme temperatures. Further, the technology allows ablation procedures to be performed in less time.
“Pulsed-Field Ablation represents the future of Atrial Fibrillation ablation procedures. The significantly shorter procedure times and notable safety benefits represent a substantial improvement over traditional methods,” said Dr. Day. “Given that PFA tends to be a faster and safer ablation procedure (when compared to radiofrequency or cryoablation) and the fact that PFA causes less inflammation and irritation to the heart, patients tend to recover much more quickly. In fact, more than 99% of our PFA patients at St. Mark’s Hospital are able to go home same-day. Patients can return to the gym in just four or five days!”
Atrial Fibrillation, or AFib, is the most common type of heart rhythm disorder or irregular heartbeat, also known as an arrhythmia. There are an estimated five million people in the U.S. living with AFib.
“Data suggests that one in four Americans will experience AFib at some point in their life,” Dr. Day says.
When operating correctly, the heart’s electrical rhythm is regulated by an area of the heart known as the sinus node. When someone has AFib, a disruption causes haphazard electrical impulses, creating a chaotic heart rhythm that may feel alarming.
The condition causes a variety of symptoms, including fast or chaotic heartbeat, a fluttering sensation in the chest, fatigue, shortness of breath and chest pain. The condition can take a toll on the heart, which has to work harder in AFib. This elevates the risk for several other health problems, including blood clots and of course, stroke.
Why blood thinners are often prescribed for AFib
Atrial Fibrillation, AFib, can cause blood to stagnate and form clots in the heart’s upper chambers (atria). Because a clot may travel to the brain and trigger a stroke, many AFib patients take anti-clotting medications. AFib patients have a higher chance of developing blood clots, which significantly increases the risk for stroke. Simply put, physicians may prescribe an anticoagulant or blood thinner medication for AFib patients to reduce that risk.
Many AFib patients may soon safely discontinue their use of the medication if they undergo a successful ablation procedure. While it is common for patients to ask their cardiologist if they can stop taking their blood thinner after the procedure, the answer depends more on a patient’s underlying risk of stroke. This must only be done under the supervision and direction of a patient’s cardiologist.
A physician and the larger care team can and will determine a patient’s risk of forming blood clots inside the heart chamber and ultimately calculate their risk for stroke. The CHA₂DS₂-VASc score calculates a quantifiable stroke risk for AFib patients. The score considers a range of factors, including age, gender and health conditions such as heart disease, diabetes and vascular disorders. The scoring system can help identify those people who are at much higher risk.
· You can utilize an online calculator like this one to determine your CHA₂DS₂-VASc score.
The CHA₂DS₂-VASc score ranges from 0 to 9, with the minimum score being 0, where no risk factors are deemed present and the maximum score is 9, where a patient has the highest risk for stroke. Maximum risk, for example: Age ≥75 [2pts], History of Stroke [2pts], Heart Failure [1pt], Hypertension [1pt], Diabetes [1pt], Vascular disease [1pt], Female sex [1pt].
For men, a low risk may be characterized by a score of 0-1; intermediate risk from 2-3; and a high risk would receive a score of 4 or higher. In women, low risk is 1-2; intermediate risk is a score of 3; and high risk is also 4 or higher.
Clinical trials may pave way for patients to safely get off medication
The Optimal Anticoagulation for Enhanced Risk Patients Post-Catheter Ablation for AFib (OCEAN) trial published in The New England Journal of Medicine involved 1,284 patients who had undergone successful catheter ablation for AFib at least one year earlier and had a CHA₂DS₂-VASc score of 1 or more (or ≥2 for women or for patients in whom vascular disease was a risk factor). Patients were randomly assigned to receive either aspirin or rivaroxaban and followed for three years. Findings revealed that when an ablation was successful, the minimally invasive therapy may allow some patients to stop taking certain anti-clotting medications.
The Long-Term Anticoagulation Discontinuation After Catheter Ablation for AFib or (ALONE-AF) randomized clinical trial was published online in The Journal of the American Medical Association (JAMA) on Aug. 31, 2025. The trial was designed to evaluate whether discontinuing oral anticoagulant therapy could lead to fewer adverse events (including stroke, systemic embolism, and major bleeding) compared with continuing direct oral anticoagulant therapy in patients without documented AFib recurrence for at least one year after ablation. The multicenter trial included 840 adult patients. The trial found that discontinuing oral anticoagulant therapy, or blood thinners, lowered the risk of the primary outcome (stroke, systemic embolism, and major bleeding) compared with continuing oral anticoagulant therapy (0.3% vs 2.2%), primarily driven by fewer major bleeding events.
In the ALONE-AF trial, a low overall incidence of stroke and an elevated risk of bleeding in the anticoagulation group were observed, results that were similar to those of the OCEAN trial. The data suggests that AFib patients who have a low-to-moderate risk of stroke and undergo successful catheter ablation and monitoring for recurrent AFib have a low enough risk of stroke that continued use of blood thinners may not be justified, particularly given the associated bleeding risks.
· RELATED: St. Mark’s Hospital takes part in PFA treatment research
The two trials suggest that with a successful AFib ablation (defined by having no recurrence for one-year post-procedure), anticoagulation could be stopped in patients whose score is 3 or lower.
Based on the ALONE-AF and OCEAN trials, Dr. Day says if men have a CHA₂DS₂-VASc score of 0-1 and women score 1-2, the typical approach now is to stop anticoagulation medication one month after a successful ablation. If a man scores 2-3 and a woman scores 3, anticoagulation is typically stopped one year after a successful ablation. If a patient’s score is 4 or higher and their goal is to get off blood thinners, patients may have the option of having a concomitant procedure.
People who might be good candidates to stop blood thinners following a successful catheter ablation are typically those who have a low risk of stroke to begin with, according to the latest research and as written in this February 2026 heart health article in Harvard Health Publishing. In general, “that means people who are younger than 65 who’ve never had a stroke and who have no major risk factors like heart failure, high blood pressure, or diabetes.”
The decision, however, should be made cautiously and in consultation with the practicing physician. It should only be done after waiting an intentional period of time after the ablation procedure is performed to allow for adequate monitoring and the determination that the ablation was successful.
“Don’t stop taking your anti-clotting medication or blood thinner without oversight by your cardiologist—your physician. Your physician should determine whether going off blood thinners is a safe and healthy choice for you,” Dr. Day warns.
People at high risk of stroke should not stop taking their medication.
Dr. Day encourages an AFib detecting smart watch or a home ECG device for all ablation patients to ensure arrhythmias do not return after an ablation.
· RELATED: Can a smart watch save your life? Monitoring your heart health with MountainStar Healthcare
“Everyone’s wearing their Apple watches, their Samsung watches, their Fitbit watches, and so many of these watches are able to diagnose Atrial Fibrillation. Or, you can actually run an EKG right from your watch,” Dr. Day said.
What about AFib patients who should not take (or cannot tolerate) anti-clotting drugs indefinitely? A Left Atrial Appendage Closure (LAAC) procedure is a nondrug alternative that may offer a good (possible) solution for particular patients. LAAC is performed by implanting a device – a tiny filter that traps clots – in the heart that permanently closes off the left atrial appendage, keeping blood clots from entering the bloodstream and traveling to the brain, thereby reducing the risk for stroke. The device is sometimes implanted at the same time as the ablation procedure.
A patient must have a CHA₂DS₂-VASc score of 3 to quality for LAAC. Patients can typically get off anticoagulation medication three months after this procedure.
Free upcoming education seminar at St. Mark’s Hospital
Dr. Day will soon host a free educational seminar for members of the public interested in learning about how to safely get off blood thinners if it is safe to do so. The seminar will take place at St. Mark’s Hospital. Be sure to follow the hospital on Facebook and Instagram to stay updated on the upcoming date and details!
· RELATED: Behind-the-scenes in the OR for your heart at St. Mark's Hospital
The Heart Center at St. Mark’s offers a variety of services for people with heart conditions, including but not limited to convergent ablation, Transcatheter Aortic Valve Replacement (TAVR), arrhythmia treatments, cardiac catheterization and left atrial appendage closure.
The Heart Center at St. Mark's cares for patients who have heart diseases and other problematic issues or conditions. The center’s highly trained team of cardiologists are experts in treating many cardiovascular conditions, including coronary artery disease, hypertension, congestive heart failure and cardiac arrhythmias. The center provides this care as an accredited Chest Pain Center.
The Heart Center at St. Mark's offers cardiovascular consults within 24 hours. For immediate access for appointments and provider questions, call (801) 288-4400.
About Dr. John D. Day
Dr. John Day graduated from medical school at Johns Hopkins University. He did his residency in internal medicine, cardiology, and cardiac electrophysiology fellowship training at Stanford University.
Dr. Day previously served as president of the Heart Rhythm Society and was the past president of the Utah chapter of the American College of Cardiology. He is recognized as an international thought leader, regularly speaking at Atrial Fibrillation medical conferences around the world about the latest developments in the treatment of AFib.
Dr. Day currently serves as the physician executive of cardiovascular services for MountainStar Healthcare (HCA Healthcare’s Mountain Division). He has a large clinical practice focusing on AFib at St. Mark's Hospital. Dr. Day warmly welcomes new patients into his practice.
The Heart Center at St. Mark’s Hospital
1160 East 3900 South Suite 2000
Salt Lake City, UT 84124
For more information, visit StMarksHeart.com or call (801) 266-3418. St. Mark’s Hospital is one of eight MountainStar Healthcare hospitals in Utah.
ADDITIONAL STORIES:
· RELATED: St. Mark's Hospital first in Utah to use new, revolutionary AFib treatment
