Late-breaking results from the PROMPT-AF, CRRF-PeAF, TRIM-AF and ARREST-AF trials presented at AHA 2024 shed new light on cutting-edge approaches to revolutionizing the management of patients with atrial fibrillation (AFIb).

In PROMPT-AF, which was also published in JAMA, researchers found that linear ablation combined with ethanol infusion of the vein of Marshall (EIVOM) in addition to pulmonary vein isolation (PVI) significantly improved freedom from atrial arrhythmias within 12 months in patients with persistent AFib compared with PVI alone. In presenting the findings, Chenyang Jiang, MD, specifically noted that freedom from atrial arrhythmia recurrence without antiarrhythmic drugs was achieved in 70.7% of patients assigned to PVI plus linear ablation and EIVOM, compared with 61.5% assigned to PVI alone.

In a related editorial comment, Miguel Valderrábano, MD, PhD, FACC, writes that the trial results demonstrate the value of EIVOM for improving outcomes of persistent AFib ablation. "Although EIVOM-specific mechanisms – such as parasympathetic denervation – may apply," he writes, "conceptually, the results provide further proof that improving the reliability of a lesion set – as EIVOM does for the mitral isthmus – can improve outcomes."

Researchers presenting on the CRRF-PeAF study found that cryoballoon ablation was not inferior to radiofrequency ablation with respect to the clinical efficacy in patients with persistent AFib at one year. Additionally, Kengo Kusano, MD, in presenting the findings, said cryoballoon ablation demonstrated less atrial structural change compared with radiofrequency ablation despite the similar recurrence rate and AFib burden after ablation between the two groups.

Findings from the TRIM-AF study found that treatment with metformin, lifestyle/risk factor modification that included diet and exercise counseling, or a combination of both did not improve AFib burden or progression when compared with standard care involving the distribution of educational pamphlets on healthy diet and exercise to patients and no individual counseling.

"I think one of the key messages from this study is that talking to patients with AFib about lifestyle/risk factor modification and giving them written instructions or more intensive individualized instructions performed well," said lead study author Mina K. Chung, MD, FACC. "However, at this time, metformin alone should not be recommended as an upstream therapy for AFib. The combination of metformin and lifestyle/risk factor modification appeared to show some benefits, but these only reached levels similar to the standard of care arm."

In ARREST-AF, aggressive risk factor management was shown to reduce arrhythmia recurrence in the 12-months following catheter ablation when compared with usual care among patients with AFib, elevated BMI and one additional cardiometabolic risk factor. In presenting the findings, Rajeev K. Pathak, MD, PhD, FACC, noted that the percentage of patients free from AFib after ablation (the primary endpoint) was 66% in the risk-factor management group compared with 42% in the usual care group. AFib symptom severity and risk-factor profiles were also significantly improved among those receiving risk factor management compared with usual care.