Addressing Atrial Fibrillation and Atrial Flutter in Patients With Severe Tricuspid Regurgitation Undergoing Evaluation for a Transcatheter Valve Procedure

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EP LAB DIGEST. 2025;25(9):6.

Bradley P Knight, MD, FACC, FHRS

Dear Readers,
As the number of transcatheter tricuspid valve replacement (TTVR) and other percutaneous TV procedures for patients with severe tricuspid regurgitation (TR) continues to grow, electrophysiologists will increasingly encounter more patients with intraprocedural heart block requiring urgent pacemaker implantation (using either a coronary sinus [CS] lead or a leadless pacemaker), and entrapped preexisting transvenous pacing and defibrillator leads.¹ Close collaboration between interventional cardiologists and electrophysiologists is critical in the care of these patients. Another issue that has received less attention in these patients with severe TR is the high prevalence of atrial fibrillation (AF). In the TRISCEND II pivotal trial, AF was present in 95% of patients.² Although not all patients were in permanent AF at the time of TTVR, it is evident that nearly all patients with severe TR have a history of AF or atrial flutter (AFL). Thus, evaluation for TTVR provides an important opportunity to reassess the management of AF. 

It is not surprising that there is a strong relationship between AF and TR. It is well recognized that TR can cause right atrial enlargement, which promotes fibrosis, conduction delay, and arrhythmogenic triggers that can lead to AF. More recently, it has been recognized that AF itself can lead to atrial enlargement, resulting in annular dilatation as well as functional mitral regurgitation (MR) and TR. There is also evidence that restoration of sinus rhythm can improve functional MR and TR. In a study published in May 2025, 80 patients with persistent AF and newly diagnosed MR or TR that was at least moderate in severity underwent either electrical cardioversion (44%) or catheter ablation (56%).³ In this study, over 90% of patients had at least moderate or severe MR or TR at baseline, but after sinus rhythm was restored, a majority of patients had only mild regurgitation at 3- and 12-month follow-up.

Although the decision to be aggressive with rhythm control in patients with AF is often based on the patient’s awareness of their AF, there are often consequences of the AF that must be considered in individual patients who might argue for a more aggressive approach. For example, even in patients who have no awareness of their AF, a high AF burden can lead to progression from paroxysmal to persistent AF, cognitive dysfunction and dementia, a further increase in their risk of stroke, ventricular dysfunction, and congestive heart failure, sinus node dysfunction, and MR/TR.

There is increasing evidence that early and aggressive rhythm control improves outcomes in patients with AF. In the EAST-AFNET 4 trial, over 2500 patients with AF were randomized to an early rhythm control approach versus usual care. Fewer than 20% of patients in the early rhythm control approach underwent catheter ablation during the 2-year follow-up, but about half remained on antiarrhythmic drug therapy. Patients in the early rhythm control approach had a significant reduction in the primary outcome, which was a composite outcome of death from cardiovascular causes, stroke, or hospitalization with worsening of heart failure or acute coronary syndrome. Therefore, when patients with severe TR are evaluated for TTVR, careful consideration should be given to more aggressive management of AF. It is also important to consider that the outcomes for catheter ablation are better in patients with paroxysmal AF compared to persistent AF, particularly when the AF has been persistent for more than 1 year. One must also consider that catheter ablation procedures largely target the left atrium with pulmonary vein isolation and posterior left atrial ablation. Therefore, many patients with severe right atrial enlargement may not benefit from the usual ablation approaches that target the left atrium. Newer anatomically or electrogram-based ablation approaches are needed for patients with refractory AF and severe TR.

It is also critical that patients with typical AFL are identified during an evaluation for TTVR. Patients with severe TR and a large tricuspid annulus often have long peri-tricuspid AFL cycle lengths. Many of these patients are misdiagnosed as having atrial tachycardias or AF, and are not considered for ablation. Given that ablation of the cavotricuspid isthmus (CTI) is associated with a very high success rate and might result in improvement in their TR, all patients with typical AFL and severe TR should undergo ablation of the CTI. It would also be a missed opportunity to not ablate their typical AFL before TTVR, especially given that ablation of the CTI would not be technically feasible after the region is covered with a transcatheter TV. 

For patients with AF in whom rhythm control has failed or is not feasible and who are being evaluated for TTVR, the adequacy of their ventricular rate control should be considered. For patients who have drug-refractory rapid ventricular rates, an atrioventricular node (AVN) ablation should be considered. However, a consideration is that standard ventricular pacing after an AVN ablation can result in ventricular desynchrony and offset the benefit of complete rate control with pacing. The usual ways to mitigate this dysynchrony include biventricular pacing from the right ventricle and CS, and conduction system pacing of the left bundle branch from the right ventricle. These strategies are not feasible for patients who have undergone TTVR, as pacing options in this population are limited to leadless systems—which currently do not allow conduction system pacing—or to single-site left ventricular pacing via the CS. 

Given that nearly all patients with severe TR undergoing TTVR have a history of AF, these patients should all be evaluated for more aggressive rhythm or rate control in addition to the usual planning for potential heart block or entrapment of pre-existing transvenous leads associated with TTVR. 

Disclosures: Dr Knight has served as a paid consultant to Medtronic and was an investigator in the PULSED AF trial. In addition, he has served as a consultant, speaker, investigator, and/or has received EP fellowship grant support from Abbott, AltaThera, AtriCure, Baylis Medical, Biosense Webster, Biotronik, Boston Scientific, CVRx, Philips, and Sanofi; he has no equity or ownership in any of these companies. Dr Knight reports payment or honoraria from Convatec for a lecture. 

References

1.    Knight BP. Managing heart rhythm and implantable device considerations in patients undergoing percutaneous transcatheter tricuspid valve replacement. EP Lab Digest. 2025;25(6):6.

2.    Hahn RT, Makkar R, Thourani VH, et al. Transcatheter valve replacement in severe tricuspid regurgitation. N Engl J Med. 2024;392(2):115-126. doi:10.1056/nejmoa2401918

3.    Schwarz F, Biewener S, Sannino A, et al. Improvement in mitral and tricuspid regurgitation in patients with atrial fibrillation after restoration of sinus rhythm - a prospective cohort study. EP Europace. 2025;27(Suppl 1):euaf085.493. doi:10.1093/europace/euaf085.493