The current standard of care for pediatric patients with unrepairable congenital valvular disease is a heart valve implant. However, current heart valve implants are unable to accommodate the somatic growth of the recipient, preventing long-term clinical success in these patients. Therefore, there is an urgent need for a growing heart valve implant for children. This article reviews recent studies investigating tissue-engineered heart valves and partial heart transplantation as potential growing heart valve implants in large animal and clinical translational research. In vitro and in situ designs of tissue engineered heart valves are discussed, as well as the barriers to clinical translation.

Background: Healthcare providers currently calculate risk of the composite outcome of morbidity or mortality associated with a coronary artery bypass grafting (CABG) surgery through manual input of variables into a logistic regression-based risk calculator. This study indicates that automated artificial intelligence (AI)-based techniques can instead calculate risk. Specifically, we present novel numerical embedding techniques that enable NLP (natural language processing) models to achieve higher performance than the risk calculator using a single preoperative surgical note. Methods: The most recent preoperative surgical consult notes of 1,738 patients who received an isolated CABG from July 1, 2014 to November 1, 2022 at a single institution were analyzed. The primary outcome was the Society of Thoracic Surgeons defined composite outcome of morbidity or mortality (MM). We tested three numerical-embedding techniques on the widely used TextCNN classification model: 1a) Basic embedding, treat numbers as word tokens; 1b) Basic embedding with a dataloader that Replaces out-of-context (ROOC) numbers with a tag, where context is defined as within a number of tokens of specified keywords; 2) ScaleNum, an embedding technique that scales in-context numbers via a learned sigmoid-linear-log function; and 3) AttnToNum, a ScaleNum-derivative that updates the ScaleNum embeddings via multi-headed attention applied to local context. Predictive performance was measured via area under the receiver operating characteristic curve (AUC) on holdout sets from 10 random-split experiments. For eXplainable-AI (X-AI), we calculate SHapley Additive exPlanation (SHAP) values at an ngram resolution (SHAP-N). While the analyses focus on TextCNN, we execute an analogous performance pipeline with a long short-term memory (LSTM) model to test if the numerical embedding advantage is robust to model architecture. Results: A total of 567 (32.6%) patients had MM following CABG. The embedding performances are as follows with the TextCNN architecture: 1a) Basic, mean AUC 0.788 [95% CI (confidence interval): 0.768–0.809]; 1b) ROOC, 0.801 [CI: 0.788–0.815]; 2) ScaleNum, 0.808 [CI: 0.785–0.821]; and 3) AttnToNum, 0.821 [CI: 0.806–0.834]. The LSTM architecture produced a similar trend. Permutation tests indicate that AttnToNum outperforms the other embedding techniques, though not statistically significant verse ScaleNum (p-value of .07). SHAP-N analyses indicate that the model learns to associate low blood urine nitrate (BUN) and creatinine values with survival. A correlation analysis of the attention-updated numerical embeddings indicates that AttnToNum learns to incorporate both number magnitude and local context to derive semantic similarities. Conclusion: This research presents both quantitative and clinical novel contributions. Quantitatively, we contribute two new embedding techniques: AttnToNum and ScaleNum. Both can embed strictly positive and bounded numerical values, and both surpass basic embeddings in predictive performance. The results suggest AttnToNum outperforms ScaleNum. With regards to clinical research, we show that AI methods can predict outcomes after CABG using a single preoperative note at a performance that matches or surpasses the current risk calculator. These findings reveal the potential role of NLP in automated registry reporting and quality improvement.

Many young adults require heart valve replacements. Current options for valve replacement in adults include mechanical valves, bioprosthetic valves, or the Ross procedure. Of these, mechanical and bioprosthetic valves are the most common options, although mechanical valve usage predominates in younger adults due to durability, while bioprosthetic valve usage predominates in older adults. Partial heart transplantation is a new method of valvular replacement that can deliver durable and self-repairing valves and allow adult patients freedom from anticoagulation therapy. This procedure involves transplantation of donor heart valves only, permitting expanded utilization of donor hearts as compared with orthotopic heart transplantation. In this review, we discuss the potential benefits of this procedure in adults who elect against the anticoagulation regimen required of mechanical valve replacements, although it has not yet been clinically established. Partial heart transplantation is a promising new therapy for the treatment of pediatric valvular dysfunction. This is a novel technique in the adult population with potential utility for valve replacement in young patients for whom anticoagulation therapy is problematic, such as women who wish to become pregnant, patients with bleeding disorders, and patients with active lifestyles.

Background: Nonadherence to follow-up after bariatric surgery is associated with lower long-term weight loss. Yet limited data exists on the youngest bariatric population, adolescents and young adults (AYA), who experience life changes in social, psychological, and behavioral domains that can interrupt follow-up. To better understand how age groups affected health outcomes in these populations, this study compared bariatric clinic follow-up adherence between AYA and assessed the impact of follow-up interruption on weight loss. Methods: Using an institutional registry, we retrospectively reviewed adolescents (age 14–18) and young adults (YA) (age ≥19–26) who underwent sleeve gastrectomy between January 2018 and May 2023. Primary outcome was follow-up compliance (1, 3, 6, 12, 18, 24 months). Secondary outcomes included median total weight loss percentage (%TWL). Lost to follow-up (LTF) was determined by the last bariatric clinic visit attended. Results: Of 73 (46.8%) adolescents and 83 (53.2%) YA, median preoperative BMI was higher in adolescents (51.0 [44.5,56.8] vs. 48.5 [43.4,51.7], p = 0.015). Median total weight loss percentage (%TWL) was greater in YA up to 6 months postoperatively (23.3 [20.5,27.4] vs. 20.2 [15.1,24.9], p = 0.008) but did not differ afterward. Median missed follow-up appointments were similar between adolescents (3[3,4]) and YA (4[3,4]). Adolescents were more likely to be LTF at 6 months (34.3% vs. 20.5%, p = 0.053). Patients in both age groups were more likely to be LTF if %TWL was in the lowest tertile at 6 months (OR 4.78, 95% CI [2.04, 11.18], p = < 0.001) or 1 year (OR 18.45, 95% CI [5.75, 59.2], p < 0.001). Conclusions: Clinic adherence in the post-bariatric AYA population is poor especially among patients with less %TWL. Identifying when AYA are at risk of LTF allows for targeted interventions to maximize adherence and potentially improve long-term health.

Objectives. The upper limit of recipient age for combined heart-kidney transplantation (HKT) remains controversial. This study evaluated the outcomes of HKT in patients aged ≥65 years. Methods. The United Network of Organ Sharing (UNOS) was used to identify patients undergoing HKT from 2005 to 2021. Patients were stratified by age at transplantation: <65 and ≥ 65 years. The primary outcome was one-year mortality. Secondary outcomes included 90-day and 5-year mortality, postoperative new-onset dialysis, postoperative stroke, acute rejection prior to discharge, and rejection within one-year of HKT. Survival was compared using Kaplan–Meier analysis, and risk adjustment for mortality was performed using Cox proportional hazards modeling. Results. HKT in recipients aged ≥65 significantly increased from 5.6% of all recipients in 2005 to 23.7% in 2021 ( ). Of 2,022 HKT patients in the study period, 372 (18.40%) were aged ≥65. Older recipients were more likely to be male and white, and fewer required dialysis prior to HKT. There were no differences between cohorts in unadjusted 90-day, 1-year, or 5-year survival in Kaplan–Meier analysis. These findings persisted after risk-adjustment, with an adjusted hazard for one-year mortality for age ≥65 of 0.91 (95% CI (0.63–1.29), ). As a continuous variable, increasing age was not associated with one-year mortality (HR 1.01 (95% CI (1.00–1.02), ) per year). Patients aged ≥65 more frequently required new-onset dialysis prior to discharge (11.56% vs. 7.82%, ). Stroke and rejection rates were comparable. Conclusion. Combined HKT is increasing in older recipients, and advanced age ≥65 should not preclude HKT.