Markers Predict Recurrence of Atrial Fibrillation after Ablation

Study suggests that certain circulating microRNA molecules are associated with the recurrence of the abnormal erratic heartbeats in some patients after ablation procedure, potentially providing markers that may help identify such patients in advance, as ablation therapy carries some risks and is expensive.

Circulating microRNAs are microRNAs (generally very stable non-coding RNAs involved in gene regulation) that have spilled out of cells into body fluids, such as blood and saliva, and can often be measured. Researchers at the Intermountain Medical Center Heart Institute have found that certain circulating microRNA could serve as markers in screening tools to help distinguish which patients with atrial fibrillation (AFib) will be more versus less likely to benefit from various therapy options.

The research team examined a series of microRNA markers in blood samples to identify AFib patients whose ablations worked the first time: they compared 85 patients who had successful ablations with 55 patients whose AFib recurred within a year. The microRNAs studied involved in inflammation, fibrosis, and heart electrical activity. They found low levels of three microRNAs in patients whose AFib came back after ablation. Those molecules had previously been associated with ablation's atrial scarring (remodeling and adverse electrical healing). Scarring and fibrosis outside of the veins that can involve both upper heart chambers often result in recurrences of AFib after an ablation.

"Our genetic makeup is important in how we respond and heal from procedures," said study senior investigator T. Jared Bunch, MD, "MicroRNA particles are a direct result of our genetic make-up. As we try to identify treatments that are tailored to an individual person, microRNA has the promise to help us determine who may be a better candidate for ablation versus other therapies."

Ablation cures AFib in 60-70% of patients, but multiple procedures are required for some. The researchers hope their findings will lead to development of tests that will help doctors determine which treatments are more likely to work for different patients, including those who wouldn't benefit from ablation.

The study was presented at the American College of Cardiology's Scientific Session on March 18, 2017, in Washington, DC, USA.