Effect of Leadless Pacemaker Implantation on Tricuspid Regurgitation

Leadless pacemakers (LLPM) eliminate trans-tricuspid leads and are presumed to reduce tricuspid regurgitation (TR), though longitudinal data are limited.

We retrospectively studied 356 patients with paired echocardiography before and after Micra implantation at a single tertiary care center. TR and MR severity were graded as none, mild, moderate, or severe. The primary analysis compared baseline with the most recent available echocardiogram. Secondary analyses examined TR severity at three mutually exclusive intervals: < 1 year, 1-3 years, and > 3 years postimplantation. Within-patient changes were assessed using paired Wilcoxon signed-rank tests.

Over a median follow-up of 540 days (IQR 67-1136 days), TR worsened in 155 patients (43.5%), improved in 89 (25.0%), and was unchanged in 112 (31.5%) at most recent available follow-up (p < 0.001). TR severity increased significantly at 1-3 years (p = 0.003) and beyond 3 years (p = 0.006), but not within the first year (p = 0.12). The proportion with severe TR increased from 6.2% at baseline to 11.2% at most recent follow-up, while none or mild TR declined from 75.5% to 65.2%. MR remained stable (p = 0.14). Within-patient comparisons showed greater TR than MR at all timepoints (all p < 0.001). Left ventricular ejection fraction declined modestly at all follow-up intervals (p < 0.001).

LLPM implantation was associated with progressive TR despite the absence of a trans-tricuspid lead, with worsening emerging beyond the first year, supporting a remodeling-based mechanism. The stability of MR argues against generalized valvular deterioration. Further studies are needed to define the clinical impact of LLPM-associated TR progression.