GP ablation during thoracoscopic surgery for advanced AF has no detectable effect on AF recurrence but causes more major adverse events, major bleeding, sinus node dysfunction, and pacemaker implantation. (Atrial Fibrillation Ablation and Autonomic Modulation via Thoracoscopic Surgery [AFACT]; NCT01091389).

Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with pronounced morbidity and mortality. Its prevalence, expected to further increase for the forthcoming years, and associated frequent hospitalizations turn AF into a major health problem. Structural and electrical atrial remodelling underlie the substrate for AF, but the exact mechanisms driving this remodelling remain incompletely understood. Recent studies have shown that microRNAs (miRNA), short non-coding RNAs that regulate gene expression, may be involved in the pathophysiology of AF. MiRNAs have been implicated in AF-induced ion channel remodelling and fibrosis. MiRNAs could therefore provide insight into AF pathophysiology or become novel targets for therapy with miRNA mimics or anti-miRNAs. Moreover, circulating miRNAs have been suggested as a new class of diagnostic and prognostic biomarkers of AF. However, the origin and function of miRNAs in tissue and plasma frequently remain unknown and studies investigating the role of miRNAs in AF vary in design and focus and even present contradicting results. Here, we provide a systematic review of the available clinical and functional studies investigating the tissue and plasma miRNAs in AF and will thereafter discuss the potential of miRNAs as biomarkers or novel therapeutic targets in AF.Electronic supplementary materialThe online version of this article (doi:10.1007/s10557-017-6736-z) contains supplementary material, which is available to authorized users.

Background: Persistent atrial fibrillation (AF) is associated with higher stroke and mortality risk than paroxysmal AF (pAF). Outcomes of catheter or surgical ablation are worse in patients with persistent AF than in pAF, and the optimal invasive rhythm control strategy has not been established. Purpose: We provide a contemporary systematic overview on efficacy and safety of catheter and minimallyinvasive surgical ablation for persistent AF. Methods: We systematically searched EMBASE, MEDLINE and CENTRAL from inception to July 2018 for randomized trials on surgical and catheter ablation, and included all study arms on persistent AF. Outcome was AF freedom after ≥12 months follow-up without AAD use. Random effects models were used to calculate proportions with 95%-confidence intervals. Safety consisted of adverse events during treatment and follow-up. Results: We included 6 studies on minimally-invasive surgical ablation and 56 on catheter ablation, involving 7624 patients with persistent AF. AF Freedom at 12 months was 69% (95%CI 64-74%) after surgical and 51% (95%CI 46-56%) after catheter ablation. More severe procedural adverse events occurred with surgery than with catheter ablation. Conclusions: In persistent AF patients, minimally-invasive surgical ablation is associated with more procedural complications, but higher AF freedom. As adverse events after surgical ablation appear more severe than in catheter ablation, a patient-tailored therapy choice is warranted.