De Novo and Progressive Pulmonary Vein Stenosis Following Pediatric Heart Transplantation: A Multicenter Retrospective Study

Background: Pulmonary vein stenosis (PVS) is a rare condition in which neointimal proliferation leads to venous and arterial hypertension. Little is known about PVS after heart transplant (HTx) in children. We sought to describe the characteristics and outcomes of children who develop PVS after HTx. Methods: We performed a retrospective review of patients ≤18 years old who underwent HTx at two HTx centers between April 2012 and October 2023. Patients with PVS were identified via database queries. Cardiac diagnosis, PVS location and extent, and outcomes were recorded. Results: Over 11.5 years, 422 patients underwent HTx across both centers. Nineteen patients with PVS (10 male) were identified, 15 with de novo PVS. Sixteen had underlying congenital heart disease (CHD), two with anomalous pulmonary venous return. PVS was diagnosed at a median of 2 months (range 2 weeks to 14 years) after HTx. At time of initial diagnosis, 13 patients had one-vessel PVS. At final follow-up, 7/19 (37%) had increases in the number of vessels involved. Six patients underwent surgery, and nine patients had stent or balloon angioplasty. Two patients were treated for pulmonary hypertension following PVS diagnosis. Three patients died from right heart failure secondary to PVS. Conclusions: This is the largest study to describe the characteristics of post-HTx PVS in children. PVS occurs in 4.5% of HTx, and underlying CHD is a strong risk factor. Multiple vessels can be involved and may require catheter-based or surgical intervention. Clinicians must be vigilant in monitoring the development of PVS in this population.