Research Reveals: Treating subclinical atrial fibrillation with blood thinners reduces risk of stroke

Research Reveals: Treating subclinical atrial fibrillation with blood thinners reduces risk of stroke

In an illuminating breakthrough, investigators from the world-renowned ARTESIA study have established that the use of blood thinners, or anticoagulants, significantly diminishes the risk of stroke in patients diagnosed with subclinical atrial fibrillation (AFib) and have an implanted cardiac device. The study involved more than 4,000 patients globally. Notably, Dr. Michael R. Gold, a cardiac specialist and electrophysiologist at MUSC Health, was one of the two U.S. investigators on the international steering committee for this historic trial.

The Proliferation of AFib

Dr. Gold suggested that the advent of pacemakers and implanted heart monitors, capable of tracking heart activity 24/7, has increased our understanding of atrial fibrillation. “Some patients have atrial fibrillation that only lasts for a few seconds, a few minutes, or a few hours. They may not even feel it,” said Gold. This type of AFib is categorized as subclinical because it lasts for less than 24 hours and often doesn’t present any physical symptoms.

AFib and Stroke – The Connection

AFib, a heart condition where electrical signals in the heart fire rapidly simultaneously, can cause the heart to beat faster than normal, disrupting the steady blood flow through the heart’s chambers. This interruption allows blood to accumulate in the upper chambers, inviting blood clots formation. Consequently, these blood clots can travel to the brain, blocking the oxygen transport, causing profound brain damage, protracted disability, or even death. Clinical AFib, which lasts 24 hours or longer, is treated with blood thinners. However, the role of these drugs in subclinical AFib has been unclear.

The ARTESIA Study

The ARTESIA study extended the findings of the 2012 ASSERT trial, which found that patients with implanted heart devices had a 2.5-fold higher risk of stroke if they had subclinical AFib. Building on that, the researchers in the ARTESIA study aimed to determine the efficacy of blood thinners in reducing stroke risk among older patients with subclinical AFib and cardiac implants.

Findings and Implications

The patients in the ARTESIA study were randomly assigned treatment with either the blood thinner apixaban or aspirin. The results indicated that patients treated with apixaban had a 37% lower risk of stroke than those treated with aspirin, albeit at a slightly heightened risk of bleeding. “Blood thinners significantly prevented having a stroke, but the trade-off for that was more bleeding. Fortunately, it wasn’t very serious bleeding,” Gold explained.

Following these findings, apixaban might receive a new indication for treating subclinical AFib. Currently, ARTESIA mainly concerns patients with implanted heart devices who have a heightened risk of stroke. However, the findings do raise pertinent questions regarding whether older people without implants may also experience unnoticeable subclinical AFib. Wearable technologies could prove beneficial in heart-rate monitoring for these patients.

“Athletic watches or other wearable devices that people use at home for heart rate monitoring might not be as accurate as implanted devices,” said Gold, “However, they’re good screening tools for identifying those who could be experiencing subclinical AFib and might benefit from treatment.”

Source of the Study

This information was collated from the comprehensive study, “Apixaban for stroke prevention in subclinical atrial fibrillation”, conducted by, among others, the ARTESIA Investigators and published in the New England Journal of Medicine (NEJM).