Michael Hunter, MD on Medika Life

A Father Lost, A Question Lingers: Rethinking Stroke Treatment

Anticoagulation shows no benefit in preventing a second stroke.

2015, my world shifted when I lost my father to a stroke at the age of 85. I vividly recall a conversation with his neurologists about the risks of strong blood thinners (anticoagulants) for stroke prevention, particularly considering the potential for bleeding complications.

Back then, this felt like the only approach.

My father decided that the potential benefits of anticoagulation were not worth the risks.

But I always wondered: Had my brilliant father chosen poorly?

Photo by Javier Allegue Barros on Unsplash

Fast forward to today, and two recent studies, NOAH-AFNET 6 and ARTESiA, are shaking things up in stroke management.

These studies are re-evaluating the use of anticoagulants for stroke prevention in a specific patient group.

This new research sparked my curiosity.

Do the new findings vindicate my father’s decision? Or because he had a first stroke with associated symptoms, is his case different?

More importantly, could they change how we treat individuals suffering a stroke moving forward?

My Goals

In this article, I’ll delve into the NOAH-AFNET 6 and ARTESiA studies, explore their potential impact on stroke treatment, and discuss what these findings might mean for the future.

I’ll end with some ways you can drop your stroke risk.

Photo by Diego PH on Unsplash

Blood Thinners to Prevent a Second Stroke

Both NOAH-AFNET 6 and ARTESiA were large-scale, randomized clinical trials designed to evaluate the effectiveness and safety of anticoagulant blood thinning or clot-preventing) therapy compared to standard treatment (aspirin or placebo) for stroke prevention.

The studies focused on a specific group of patients: those with a history of stroke or transient ischemic attack (TIA) detected by implanted cardiac devices.

Transient Ischemic Attack (TIA)


These TIAs, often referred to as “mini-strokes,” are brief episodes of neurological dysfunction that typically last less than an hour and leave no lasting damage.

However, they serve as a warning sign for potential future strokes.

Here is where my dad’s case differs. Doctors diagnosed my father’s stroke because of his symptoms.

Photo by National Cancer Institute on Unsplash

In contrast, in these studies, doctors identified the strokes or TIAs through implanted cardiac devices that continuously monitor heart rhythm.

This approach allowed researchers to identify a subgroup of patients who might have experienced these events without exhibiting outward symptoms, potentially putting them at a higher risk of future strokes.

Study Results: Balancing Risks and Benefits

When analyzed using a meta-analysis approach, NOAH-AFNET 6 and ARTESiA findings revealed some intriguing results.

The studies demonstrated this:

For patients with a history of device-detected stroke or TIA, using blood thinners (specifically edoxaban and apixaban in these studies) reduced the risk of ischemic stroke (strokes caused by blood clots blocking blood flow to the brain) compared to aspirin or placebo.

However, the studies also highlighted a crucial trade-off.

While these drugs reduced ischemic stroke risk, there was a corresponding increase in the risk of major bleeding events associated with blood thinners.

Let’s explore how many people we would have to treat to see a benefit from blood thinning drugs.

A Personalized Approach on the Horizon?

The findings from NOAH-AFNET 6 and ARTESiA represent a significant shift in stroke prevention strategies.

Traditionally, the risk of bleeding complications often outweighed the potential benefits of blood thinners in stroke patients.

Thus, my father declined anticoagulants.

Photo by KOMMERS on Unsplash

However, these studies suggest that the balance might tip favor anticoagulation for a specific subgroup with device-detected stroke or TIA.

Breaking Down the Numbers

Taya Glotzer, MD, an electrophysiologist at the Hackensack University Medical Center (New Jersey, USA), highlights the relatively small reduction in stroke risk observed in both studies.

In ARTESiA, the annual stroke reduction was just 0.44 percent, requiring treatment for 250 patients to prevent one stroke.

NOAH-AFNET 6 showed even smaller reductions, with a 0.2 percent decrease in the main trial and a 0.7 percent reduction in patients with stroke history.

The combined results translate to this:

We would need to treat 500 (for the ARTESiA study) and 143 patients (for NOAH-AFNET 6), respectively, to prevent a single stroke.

Photo by digitale.de on Unsplash

Benefits Are Small

Dr. Taya Glotzer, an electrophysiologist at Hackensack University Medical Center, emphasizes that these reductions wouldn’t meet the “class 1 recommendation” criteria for blood thinners, which typically require a 1–2% annual stroke reduction.

However, she does acknowledge a positive takeaway: the studies demonstrate a “very, very low” stroke rate in patients with a history of stroke.

My Take

These studies offer valuable insights, but we should exercise caution.

While blood thinners might be beneficial for some stroke patients with implanted cardiac devices, the reduced stroke risk comes with an increased risk of bleeding.

More research is needed to determine the optimal approach for this specific patient population.

The recent research findings pave the way for a more personalized approach to stroke prevention.

By considering factors like the type of stroke, underlying risk factors, and implanted cardiac devices, doctors can have a more nuanced conversation with patients about anticoagulant therapy’s potential benefits and risks.

This comprehensive approach can empower patients to make informed decisions about their stroke prevention plan.

A clot in a blood vessel. Adobe Stock Photos.

However, it’s important to remember that these studies are just the beginning.

More research is needed to fully understand the long-term implications of blood thinners in this patient population and further refine treatment strategies.

Perhaps, by exploring this new landscape, we can honor the memory of those lost and pave the way for better treatment options for those facing stroke.

Take Action

Here are some steps you can take to drop your stroke risk:

  • Keep your cholesterol and blood pressure in the normal range
  • Don’t smoke
  • Keep your glucose (blood sugar) in the normal range
  • If you have heart disease, get treatment
  • Maintain a healthy weight
  • Be active
  • Eat a balanced diet.

Taking these steps can also help lower your risk of diabetes and heart disease.


While blood thinners reduce the risk of ischemic stroke, they also increase the risk of major bleeding events.

Before 2024, stroke prevention felt like a clear-cut decision — a binary choice between anticoagulation and not.

Now, we find ourselves in a complex grey zone, carefully weighing the risk of stroke against the potential for bleeding complications with blood thinners. This shift in our understanding requires a more nuanced approach to stroke treatment.

Anticoagulation Shows No Benefit in Preventing Second Stroke

For patients who have had a stroke, anticoagulation with edoxaban didn’t reduce the risk for another.


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Michael Hunter, MD
Michael Hunter, MD
I received an undergraduate degree from Harvard, a medical degree from Yale, and trained in radiation oncology at the University of Pennsylvania. I practice radiation oncology in the Seattle area.

Michael Hunter, MD

I received an undergraduate degree from Harvard, a medical degree from Yale, and trained in radiation oncology at the University of Pennsylvania. I practice radiation oncology in the Seattle area.

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