Introduction Changes in tricuspid regurgitation (TR), mitral regurgitation (MR) and left ventricular ejection fraction (LVEF) are frequently noted after conventional pacemaker implantation but prior studies evaluating whether left bundle branch area (LBBA) or leadless pacemakers modify those observed changes are limited. This study aims to compare changes in TR, MR and LVEF after implantation of conventional right ventricular (RV), leadless, and LBBA pacemakers.

Methods Inclusion criteria were first-time pacemaker implantation and pre- and post-implant echocardiography. Change in TR, MR and LVEF were analyzed using post-hoc adjusted Kruskal-Wallis and chi-squared testing, and multivariable ordinal logistic regression.

Results Among 400 consecutive patients (RV, n=228; LBBA, n=136; leadless, n=36), the change in TR grade differed between pacemaker types (median [interquartile range] grade change: LBBA 0[0,0], leadless 0[0,1], RV 0[0,1]; p<0.01). The prevalence of severe TR was similar between pacemaker groups before implant (p=0.93), but more frequent following implant of RV and leadless pacemakers compared to LBBA pacemakers (p=0.02). In multivariable ordinal logistic regression, leadless (OR 2.26, p=0.03) and RV pacemakers (OR 1.66, p=0.03) both predicted TR worsening compared to LBBA. The change in MR grade differed between pacemaker types (grade change: LBBA 0[-1,0], leadless 0[0,1], RV 0[0,0]; p<0.01). The change in LVEF differed between pacemaker types (LVEF change: LBBA 0[- 5,7]%, leadless -5[-14,1]%, RV -3[-9,2]%; p<0.01).

Conclusion Change in TR, MR grade and LVEF following pacemaker implant varied by pacemaker type. Compared to leadless and RV, LBBA pacemaker implant was associated with more favorable changes in valvular and ventricular function.

Conflict of interest disclosure: AZ, IA, MA, AE, EY, MU: none. BA is on a steering committee, receives research support, and is a consultant for Medtronic, a consultant for Abbott, Biosense Webster, and receives research support from Pfizer and BMS.

This work was supported in part by the Inova Grants Management Office and Karolinska Institutet.

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An approval was obtained by the Inova Health System Institutional Review Board (IRB) with a retrospective waiver of individual informed consent (approval number INOVA-2024-86).

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