Growth and maturation of heart valves leads to changes in endothelial cell distribution, impaired function, decreased metabolism and reduced cell proliferation.

Risk factors of heart valve disease are well defined and prolonged exposure throughout life leads to degeneration and dysfunction in up to 33% of the population. While aortic valve replacement remains the most common need for cardiovascular surgery particularly in those aged over 65, the underlying mechanisms of progressive deterioration are unknown. In other cardiovascular systems, a decline in endothelial cell integrity and function play a major role in promoting pathological changes, and while similar mechanisms have been speculated in the valves, studies to support this are lacking. The goal of this study was to examine age-related changes in valve endothelial cell (VEC) distribution, morphology, function and transcriptomes during critical stages of valve development (embryonic), growth (postnatal (PN)), maintenance (young adult) and aging (aging adult). Using a combination of in vivo mouse, and in vitro porcine assays we show that VEC function including, nitric oxide bioavailability, metabolism, endothelial-to-mesenchymal potential, membrane self-repair and proliferation decline with age. In addition, density of VEC distribution along the endothelium decreases and this is associated with changes in morphology, decreased cell-cell interactions, and increased permeability. These changes are supported by RNA-seq analysis showing that focal adhesion-, cell cycle-, and oxidative phosphorylation-associated biological processes are negatively impacted by aging. Furthermore, by performing high-throughput analysis we are able to report the differential and common transcriptomes of VECs at each time point that can provide insights into the mechanisms underlying age-related dysfunction. These studies suggest that maturation of heart valves over time is a multifactorial process and this study has identified several key parameters that may contribute to impairment of the valve to maintain critical structure-function relationships; leading to degeneration and disease.

An Analysis of 183 Heart Transplants for Pediatric or Congenital Heart Disease-Impact of High Panel Reactive Antibody.

BACKGROUND: We reviewed our management strategy and outcome data for all 179 patients with pediatric and/or congenital heart disease who underwent 183 heart transplants from January 1, 2011, to December 31, 2021, and evaluated the impact of elevated panel reactive antibody (PRA). METHODS: High PRA was defined as PRA >10%. Univariate associations with long-term survival were assessed with Cox proportional hazards models. Impact of high PRA on survival was estimated with multivariable models. RESULTS: PRA >10% was present in 60 of 183 transplants (32.8%), who were more likely to have prior cardiac surgery, higher number of prior cardiac operations, prior sternotomy, prior heart transplant, and positive crossmatch (24 of 60 [40.0%] vs 11 of 123 [8.9%], P < .0001). Univariate associations with long-term survival include acquired heart disease vs congenital or retransplant (hazard ratio [HR], 0.18; 95% CI, 0.053-0.593; P = .005), prior cardiac surgery (HR, 5.6; 95% CI, 1.32-23.75; P = .020), number of prior cardiac operations (HR, 1.3 for each additional surgery; 95% CI, 1.12-1.50; P = .0004), single ventricle (HR, 2.4; 95% CI, 1.05-5.48; P = .038), and preoperative renal dysfunction (HR, 3.4; 95% CI, 1.43-7.49; P = .002). In multivariate analysis, high PRA does not impact survival when controlling for each of the factors shown in univariable analysis to be associated with long-term survival. The Kaplan-Meier method provided the following survival estimates at 1 year (95% CI) and 5 years (95% CI) after cardiac transplantation: All patients, 93.6% (89.9%-97.3%) and 85.8% (80.0%-92.1%); PRA <10%, 96.6% (93.4%-99.9%) and 86.7% (79.6%-94.3%); and PRA >10%, 86.7% (78.0%-96.4%) and 83.8% (74.0%-95.0%). Despite high PRA being associated with higher mortality at 1 year (14.9% vs 3.8%, P = .035), no significant difference exists in Kaplan-Meier overall survival at 5 years posttransplant in patients with and without high PRA (log-rank P = .4). CONCLUSIONS: In our cohort, 5-year survival in patients with high PRA (PRA >10%) is similar to that in patients without high PRA (PRA <10%), despite the presence of more risk factors in those with high PRA. Individualized immunomodulatory strategies can potentially mitigate the risk of high PRA.