Atrial fibrillation (AF) is linked with more frequent progression of tricuspid regurgitation (TR) following mitral valve transcatheter edge-to-edge repair (M-TEER) in the OCEAN registry, as well as reduced TR improvement post-procedurally. Prior to M-TEER, AF was also associated with a higher prevalence of significant TR, according to the analysis of the ongoing, prospective Japanese registry in patients with mitral regurgitation (MR) undergoing M-TEER. The findings were published Monday online in the JACC: Cardiovascular Interventions, ahead of print, led by Shingo Matsumoto, MD, from Tokai University School of Medicine, in Japan and the University of Glasgow, Scotland. The researchers noted that the interplay between AF and TR has been widely noted, with the hypothesis that AF could lead to TR development via a change in right heart condition. This pathophysiological link has received “growing attention,” they added. “However, this interaction is complex, and the precise role of AF in patients undergoing M-TEER remains unclear,” wrote Matsumoto and colleagues. “Notably, little is known about the impact of AF on the dynamic nature of TR status and right heart structure and function after M-TEER, in both patients with and those without pre-existing significant TR. Additionally, the question remains whether the relationship between TR and clinical outcomes after M-TEER is modified by the presence of AF.” Despite the gap in knowledge, there remains a high prevalence of AF in those receiving TR intervention, accounting for around 40% to 50% of those undergoing tricuspid valve surgery and 80% to 90% of those given transcatheter treatments. The current study therefore set out to better define understanding of the association between AF and TR in 3,666 M-TEER patients who received the MitraClip (Abbott Cardiovascular) G2 or G4 system from April 2018 to June 2023 across 21 Japanese centers. They were indicated in primary MR due to high surgical risk and in secondary MR because of symptomatic status despite optimal medical therapy and, if applicable, cardiac resynchronization therapy. At baseline, AF was seen in 2,253 (61.5%) and 1,059 patients (28.9% had post-procedural TR of moderate or greater at discharge, the researchers said. The patients were divided into 4 groups; those with no AF and no TR (n = 1,184), no AF with significant TR (n = 229), AF and no TR (1,423), or AF with significant TR of moderate or greater at discharge (n = 830). At the post-M-TEER baseline (at discharge), those with AF and significant TR were older (mean 81.5 years ± 7.4 vs 77.2 years ± 10.7 in no AF and no TR, 77.7 years ± 11.4 in no AF with significant TR, and 78.7 years ± 8.9 in those with AF and no TR), and they had a higher proportion of clinical frailty score ≥4 compared with the other 3 groups. Left ventricular ejection fraction (LVEF) was also higher for the AF and significant TR group (a mean of 49.8% vs 42.7% in no AF and no TR, 46.8% in no AF with significant TR and 44.1% in AF with no TR). Meanwhile, N-terminal pro-B-type natriuretic peptide (NT-proBNP) level was higher in patients with TR moderate or greater compared with those with no TR (mild or less), regardless of the presence of AF. The researchers found that, before receiving M-TEER, significant TR was more common in AF patients (45.4% of those with AF vs 24.1% of those without; P<0.001). AF was also associated with more frequent TR progression and less common improvement during follow-up periods 1 month post-procedurally (TR ≥2+ in 24.1% before M-TEER vs 16.2% after M-TEER compared with TR ≥2+ in 45.3% vs 36.8%, respectively, post-procedurally) and for every year after M-TEER. TR grades of moderate or greater after M-TEER were in turn associated with a higher adjusted risk for cardiovascular death or HF hospitalization, especially in patients with AF (adjusted hazard ratio [HR]: 1.96; 95% confidence interval [CI]: 1.56-2.46; P for interaction = 0.02). Both AF and TR were associated with TA remodeling and a larger TA diameter index at baseline and during follow-up, the researchers added, "with distinct patterns observed according to MR and TR pathologies.” For those with AF, this trend was especially seen in those with persistent or permanent conditions. "Given the vicious cycle of AF and TR, our findings support comprehensive management of TR, including the consideration of early therapeutic intervention for AF," the researchers concluded. Source: Matsumoto S, Ohno Y, Noda A, et al. Atrial Fibrillation and Tricuspid Regurgitation in Patients Undergoing Mitral Valve Transcatheter Edge-to-Edge Repair. JACC: Cardiovasc Interv 2026; DOI: 10.1016/j.jcin.2025.10.041. Image Credit: ibreakstock – stock.adobe.com