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The article presents a study on the role of the 4q25 chromosomal locus in the prediction of atrial fibrillation (AF) after coronary artery bypass graft surgery. Multivariate predictors of postoperative AF were identified by genotyping 45 single-nucleotide polymorphisms (SNPs) including the 4q25 area. Results show that the genetic variations in the 4q25 chromosomal region were associated with postoperative AF after bypass graft surgery.

Introduces the essential concepts of cardiovascular tissue engineering. Achievements in the field; Basic developmental biology of heart valves and blood vessels; Cell source for tissue-engineered valves and vessels; Discussion of the heart valve and blood vessel development; Summary of the 2001 research on progenitor and stem cells.

Purpose of Review: Modifiable patient-related risk factors, such as physical, emotional, and cognitive frailty, poor nutritional status, sleep hygiene, anemia, alcohol abuse, and smoking reduce a patient's ability to effectively recover from the insult of surgery. Herein, we review the value of implementing a comprehensive prehabilitation program for patients undergoing thoracic surgery., Recent Findings: Although prehabilitation is not a novel concept, recent evidence suggest that 4-6 weeks of prehabilitation prior to surgery is likely to increase a patient's preoperative functional status allowing patients to return to independence earlier after surgery. The value of a prehabilitation program can be determined using cost effectiveness analysis, cost-benefit analysis (CBA), cost-utility analysis (CUA), and cost-consequence analysis (CCA)., Summary: It stands to reason that well designed prehabilitation programs can add value by improving quality metrics at a lower cost to our healthcare system. Definitive randomized trials are needed to confirm this notion., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Ventricular dysfunction (VnD) after primary coronary artery bypass grafting is associated with increased hospital stay and mortality. Natriuretic peptides have compensatory vasodilatory, natriuretic, and paracrine influences on myocardial failure and ischemia. The authors hypothesized that natriuretic peptide system gene variants independently predict risk of VnD after primary coronary artery bypass grafting., Methods: A total of 1,164 patients undergoing primary coronary artery bypass grafting with cardiopulmonary bypass at two institutions were prospectively enrolled. After prospectively defined exclusions, 697 patients of European descent (76 with VnD) were analyzed. VnD was defined as need for at least 2 new inotropes and/or new mechanical ventricular support after coronary artery bypass grafting. A total of 139 haplotype-tagging single nucleotide polymorphisms (SNPs) within 7 genes (NPPA, NPPB, NPPC, NPR1, NPR2, NPR3, CORIN) were genotyped. SNPs univariately associated with VnD were entered into logistic regression models adjusting for clinical covariates predictive of VnD. To control for multiple comparisons, permutation analyses were conducted for all SNP associations., Results: After adjusting for clinical covariates and multiple comparisons within each gene, seven NPPA/NPPB SNPs (rs632793, rs6668352, rs549596, rs198388, rs198389, rs6676300, rs1009592) were associated with decreased risk of postoperative VnD (additive model; odds ratios 0.44-0.55; P = 0.010- 0.036) and four NPR3 SNPs (rs700923, rs16890196, rs765199, rs700926) were associated with increased risk of postoperative VnD (recessive model; odds ratios 3.89-4.28; P = 0.007-0.034)., Conclusions: Genetic variation within the NPPA/NPPB and NPR3 genes is associated with risk of VnD after primary coronary artery bypass grafting. Knowledge of such genotypic predictors may result in better understanding of the molecular mechanisms underlying postoperative VnD.

Background: An estimated 275,000 patients undergo heart valve replacement each year. However, existing solutions for valve replacement are complicated by the morbidity associated with lifelong anticoagulation of mechanical valves and the limited durability of bioprostheses. Recent advances in tissue engineering and our understanding of stem cell biology may provide a lifelong solution to these problems., Methods and Results: Mesenchymal stem cells were isolated from ovine bone marrow and characterized by their morphology and antigen expression through immunocytochemistry, flow cytometry, and capacity to differentiate into multiple cell lineages. A biodegradable scaffold was developed and characterized by its tensile strength and stiffness as a function of time in cell-conditioned medium. Autologous semilunar heart valves were then created in vitro using mesenchymal stem cells and the biodegradable scaffold and were implanted into the pulmonary position of sheep on cardiopulmonary bypass. The valves were evaluated by echocardiography at implantation and after 4 months in vivo. Valves were explanted at 4 and 8 months and examined by histology and immunohistochemistry. Valves displayed a maximum instantaneous gradient of 17.2+/-1.33 mm Hg, a mean gradient of 9.7+/-1.3 mm Hg, an effective orifice area of 1.35+/-0.17 cm2, and trivial or mild regurgitation at implantation. Gradients changed little over 4 months of follow-up. Histology showed disposition of extracellular matrix and distribution of cell phenotypes in the engineered valves reminiscent of that in native pulmonary valves., Conclusions: Stem-cell tissue-engineered heart valves can be created from mesenchymal stem cells in combination with a biodegradable scaffold and function satisfactorily in vivo for periods of >4 months. Furthermore, such valves undergo extensive remodeling in vivo to resemble native heart valves.

Having a reliable method of delivering cells to polymer scaffolds in vitro is fundamental to the development of tissue engineered structures. This paper compares the efficacy of two rotating systems for this purpose. Ten conduits, measuring 40 mm by 10 mm, were fabricated from polyglycolic acid mesh and poly-4-hydrobutyrate. Five conduits were placed in a rotating wall vessel (RWV, Synthecon Inc., Houston, TX), developed by the National Aeronautics and Space Administration (NASA); five conduits were also placed in rotating individual sealed tubes (RISTs). Medium in the RWV was left unchanged for the duration of the experiment; medium in the RISTs required daily change. Samples of the discarded medium and samples from the RWV were analyzed for pH, pCO2, pO2, and lactate concentration. Constructs were assayed for DNA content as a surrogate for cell number. In the RWV, pH, pCO2, and pO2 remained stable, while the lactate concentration gradually increased. The measure of PO2 did not differ significantly between the RWV and the RISTs, but the pH was lower and the pCO2 and the lactate concentration measurements were higher in the RIST system at each time point (p = 0.001). After 6 days (p = 0.001), the total DNA per conduit was 226+/-7 microg for the conduits seeded in the RISTs and 396+/-18 microg for the conduits in the RWV, suggesting that the RWV is superior to the RIST system for delivering cells to polymer scaffolds.