Lead‐to‐Vein Ratio and Long‐Term Vascular Safety After Transvenous Pacing in Children Weighing ≤15 Kg
Michel Cabrera Ortega, Juan Carlos Ramiro Novoa, Osmin Castañeda Chirino, Adel Eladio González Morejón, Giselle Serrano Ricardo, Yoel Coto Hernández, Mabel Elena Dominguez Gonzalez, Liz Coto Pérez, Agustín Fernández‐CisnalABSTRACT
Background
Transvenous pacing in low‐weight children is technically feasible, but its clinical use depends on long‐term venous patency, system performance, and ventricular function. We aimed to describe imaging‐defined venous abnormalities and clinically overt vascular events after first transvenous pacemaker implantation and to explore whether the lead‐to‐vein ratio provides anatomical information beyond body weight.
Methods
This prospective observational cohort included 35 children weighing ≤15 kg undergoing first transvenous pacemaker implantation between 2010 and 2020. The primary vascular endpoint was imaging‐defined venous thrombosis, occlusion, or stenosis ≥50%; clinical impact was recorded separately. Device‐related safety, minimum venous diameter, lead‐to‐vein ratio, ventricular function, synchrony, and paced QRS duration were analyzed using non‐parametric, exact, and exploratory univariable tests.
Results
Median follow‐up was 6.7 [4.5–8.2] years. Eleven patients weighed <10 kg and 3 weighed <5 kg. The imaging‐defined vascular endpoint occurred in 6/35 patients; 5 were asymptomatic surveillance findings and 1 was clinically symptomatic. The lead‐to‐vein ratio was higher in patients with the endpoint than in those without events (0.59 [0.55–0.63] vs. 0.47 [0.43–0.51]; p = 0.003). A ratio >0.55 was associated with more frequent imaging‐defined endpoints (4/8 vs. 2/27; odds ratio 12.5; 95% confidence interval 1.7–92.3). Left ventricular ejection fraction remained preserved.
Conclusion
During the first transvenous system lifespan, imaging‐defined venous abnormalities were relatively frequent but mostly asymptomatic, whereas clinically overt vascular complications were uncommon. The lead‐to‐vein ratio may support anatomical pre‐implant risk stratification, although multicenter validation and follow‐up beyond generator replacement are required.