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Comprehensive clinical and imaging-based surveillance represents a fundamental aspect in the management of thoracic aortic aneurysms (TAAs), affording the opportunity to identify intermediate-sized TAAs before the onset of worrying symptoms or devastating acute aortic dissection/rupture. Currently, size-based indices are favoured as the major determinants driving patient selection for surgery, as supported by aortic guidelines, although it is recognised that smaller sub-threshold TAAs may still confer substantial risks. Prophylactic aortic surgery can be offered within set timeframes at dedicated aortic centres with excellent outcomes, to mitigate the threat of acute aortic complications associated with repeatedly deferred intervention. In this commentary, we discuss a recent article from the Journal of Cardiac Surgery which highlights important socio-economic disparities in TAA surveillance and follow-up.

Interspecific interactions within biofilms determine relative species abundance, growth dynamics, community resilience, and success or failure of invasion by an extraneous organism. However, deciphering interspecific interactions and assessing their contribution to biofilm properties and function remain a challenge. Here, we describe the constitution of a model biofilm composed of four bacterial species belonging to four different genera (Rhodocyclus sp., Pseudomonas fluorescens, Kocuria varians, and Bacillus cereus), derived from a biofilm isolated from an industrial milk pasteurization unit. We demonstrate that the growth dynamics and equilibrium composition of this biofilm are highly reproducible. Based on its equilibrium composition, we show that the establishment of this 4-species biofilm is highly robust against initial, transient perturbations but less so towards continuous perturbations. By comparing biofilms formed from different numbers and combinations of the constituent species and by fitting a growth model to the experimental data, we reveal a network of dynamic, positive, and negative interactions that determine the final composition of the biofilm. Furthermore, we reveal that the molecular determinant of one negative interaction is the thiocillin I synthesized by the B. cereus strain, and demonstrate its importance for species distribution and its impact on robustness by mutational analysis of the biofilm ecosystem.

Response to Letter to Editor Regarding: Equivalent outcomes with minimally invasive and sternotomy mitral valve repair for degenerative mitral valve disease. J Card Surg. 2021; 36:2636-43.Authors: Ramsey S. Elsayed, MD MS1, Brittany Abt, MD1, and Michael E. Bowdish, MD MS1,2Institutions and Affiliations: 1Division of Cardiac Surgery, Department of Surgery, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA2Department of Preventive Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USAAddress for Correspondence: Dr. Michael E. Bowdish, Associate Professor of Surgery and Preventive Medicine; Department of Surgery, Keck School of Medicine of USC; University of Southern California; 1520 San Pablo Street, HCC II Suite 4300; Los Angeles, CA 90033; Phone: (323)-442-5849; Email: Michael.Bowdish@med.usc.eduConflicts of Interest/Competing Interests: NoneFunding: Research reported in this publication was supported by the Department of Surgery of the Keck School of Medicine of USC. MEB is partially supported by UM1-HL11794 from the National Heart Lung and Blood Institute of the National Institutes of Health.To the editor,We would like to thank Song et. al. for their letter regarding our recent publication in the Journal of Cardiac Surgery titled “Equivalent outcomes with minimally invasive and sternotomy mitral valve repair for degenerative mitral valve disease”1. They asked some important questions and brought up valuable points that are worthy of discussion.Regarding the selection criteria we use for operative approach for mitral valve repair operations, it is primarily based on collective surgeon-patient decision making. However, patients with a previous history of cardiac surgery or peripheral vascular disease (which would render peripheral cannulation difficult), and those in need of concomitant cardiac procedures such as coronary artery bypass grafting, aortic replacement, or biatrial ablation, are not offered a minimally invasive approach. Regarding the role of artificial chordae (neochordae) in mitral valvuloplasty, we use elongated polytetrafluorethylene made of interrupted GoreTex (Gore-Tex, WL Gore and Associates, Inc., Flagstaff, AZ) sutures placed in a horizontal mattress fashion. These neochordae are routinely used to repair elongated or ruptured chordae causing mitral valve prolapse or regurgitation.2 Typically, the neochordae are used in the anterior leaflet of the mitral valve. The etiologies of degenerative mitral valve disease are comprised of myxomatous degeneration of the MV, fibroelastic deficiency including so called Barlow’s valves, and dystrophic calcification of the mitral annulus.3 While the etiologies are not mutually exclusive and may overlap, myxomatous degeneration and fibroelastic deficiencies resulting in severe, symptomatic MR were the most common indications for operation in our patient population. As mentioned by Song and colleagues, the success and durability of MVr can vary depending on etiology, particularly on how much of the valve apparatus is affected by pathology. While not examined in this paper specifically, previous papers (including Tatum et al. conducted at our institution), have demonstrated that anterior leaflet repair is significantly associated with recurrence and progression of MR after surgery, whereas isolated posterior repair is protective.3,4The operative team was similar in all cases, whereas the senior author (VAS) performed over 85% of the total procedures and nearly 100% of the minimally invasive procedures. The success rate of the minimally invasive cohort was 100% (as defined by the Society of Thoracic Surgeons). There was one conversion to conventional sternotomy in the minimally invasive cohort (.003%) for bleeding control.Finally, Song and colleagues are to be congratulated on their robotic and thoracoscopic mitral valvuloplasty results. Their 10-year total robotic mitral valve valvuloplasty results showing excellent cardiac function with 93% of patients in NYHA classes I and II.5 Furthermore, their early thoracoscopic results were very good with one operative mortality and only two reoperations demonstrating thoracoscopic mitral valvuloplasty is a technically feasible, safe, effective, and reproducible technique.6References:Bowdish ME, Elsayed RS, Tatum JM, Cohen RG, Mack WJ, Abt B, Yin V, Barr ML, Starnes VA. Equivalent outcomes with minimally invasive and sternotomy mitral valve repair for degenerative mitral valve disease. J Card Surg. 2021 Aug;36(8):2636-2643. PMID: 33908645.Bortolotti U, Milano AD, Frater RW. Mitral valve repair with artificial chordae: a review of its history, technical details, long-term results, and pathology. Ann Thorac Surg. 2012 Feb;93(2):684-91. PMID: 22153050.David, Tirone E. ”Durability of mitral valve repair for mitral regurgitation due to degenerative mitral valve disease.” Annals of cardiothoracic surgery 4.5 (2015): 417.Tatum, James M., et al. ”Outcomes after mitral valve repair: a single-center 16-year experience.” The Journal of thoracic and cardiovascular surgery 154.3 (2017): 822-830.Zhao H, Gao C, Yang M, Wang Y, Kang W, Wang R, Zhang H. Surgical effect and long-term clinical outcomes of robotic mitral valve replacement: 10-year follow-up study. J Cardiovasc Surg (Torino). 2021 Apr;62(2):162-168. PMID: 33302613.Cui H, Zhang L, Wei S, Li L, Ren T, Wang Y, Jiang S. Early clinical outcomes of thoracoscopic mitral valvuloplasty: a clinical experience of 100 consecutive cases. Cardiovasc Diagn Ther. 2020 Aug;10(4):841-848. PMCID: PMC7487400.

Increased prevalence of Autoimmune Diseases in Children with Chronic Spontaneous UrticariaMichelle Le, MD1, Lydia Zhang MD2, Sofianne Gabrielli MSc2, Connor Prosty BSc, MD(c)1, Laura May Miles LLM, MD(c)2, Elena Netchiporouk, MD, MSc1, Sharon Baum, MD3, Shoshana Greenberger, MD3, Luis F. Ensina, MD, MSc, PhD4, Fatemeh Jafarian, MD1, Xun Zhang, PhD5, Moshe Ben-Shoshan, MD, MSc21Division of Dermatology, McGill University, Montreal, QC, Canada2Division of Pediatric Allergy and Clinical Immunology, Department of Pediatrics, McGill University Health Centre, Montreal, QC, Canada3Department of Dermatology, Chaim Sheba Medical Center, Tel-Aviv University, Sackler School of Medicine, Tel Hashomer, Israel4Department of Pediatrics, Federal University of São Paolo, Brazil5Centre for Outcome Research and Evaluation, Research Institute of McGill University Health Centre, Montreal, QC, CanadaCorrespondence: Michelle Le, M.D., 1001 Decarie Blvd, Montréal, Québec, H4A 3J1 email: michelle.le@mail.mcgill.caArticle type: LetterManuscript word count: 981References : 10Tables : 1Figures: NoneFunding sources : NoneConflicts of interest: None declaredIRB Approval Status : Reviewed and approved by McGill University Health Centre; approval 12-255GEN

Nitric oxide has been used to treat respiratory failure in post-pediatric cardiac surgical patients. High frequency oscillator ventilation is used to rescue infants who have failed conventional ventilation. In this issue a study is presented showing the benefit of combining these two therapies for improved outcomes in infants with hypoxic respiratory failure after congenital heart surgery

Cutting through the Fat: Relationship Between Comorbidities and Arrhythmias in Hypertrophic Cardiomyopathy Alan Sugrue MBBCh, MSc; David Lin MD, FHRSCardiovascular Division, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PAManuscript word count: 1223Conflicts of interest: noneFunding: noneAddress for Correspondence:David Lin, MDHospital of the University of Pennsylvania3400 Spruce Street9 Founders PavilionPhiladelphia, PA 19104Email: david.lin@pennmedicine.upenn.edu

Ventricular outflow is a common site for idiopathic PVCs and repetitive ventricular arrhythmias. Sites of origin of these arrhythmias may vary from the sites of earliest activation mapped. Better definition of the site of origin can help avoid unnecessary large volume ablation to suppress these arrhythmia.

Epicardial surgical clip is showed to be a safe and effective tool in order to achieve a complete left atrial appendage (LAA) exclusion thus reducing the risk of stroke in patients with atrial fibrillation. Historically, other methods as surgical ligation, internal oversewing or external stapling showed to be largely uneffective with an incidence of LAA residual flow ranging from 25% to 35% thus, increasing per se 5- to 10-fold the risk of stroke. Epicardial LAA exclusion by means of external clip could be potentially released under transesophageal echocardiographic guidance thus increasing the procedural success rate of complete closure with no residual stump left.

An elderly female with multiple comorbidities presented with acute onset of severe urinary retention immediately following placement of an intrathecal morphine pain pump. This case highlights the need to closely monitor chronic pain patients with complex medical histories who may be uniquely predisposed to opioid-mediated severe urinary retention.

Robotic totally endoscopic techniques to perform the LITA to LAD graft, coupled with PCI, provides the least invasive option to achieve hybrid coronary revascularization (HCR). Shorter hospital stay and reduced need for blood transfusions have been consistently being reported by several studies along with similar long-term outcomes. Considerable variations exist in the definition of HCR which can be single or two-staged with surgical revascularization being carried out after PCI or vice versa. Variations also exist with respect to usage of cardiopulmonary bypass, surgical incisions, and use of minimally invasive robotic techniques. The different strategies of HCR do not lead to similar outcomes and the findings of one strategy cannot be extrapolated to the entire group. Studies reporting different strategies of HCR, should ideally provide more granular data when reporting outcomes.

Patients with a bicuspid aortic valve (BAV) are at increased risk of valvular regurgitation compared to their counterparts with a tri-leaflet aortic valve. There is now increasing emphasis to offer BAV repair to mitigate the risks of prosthesis-related complications, including thromboembolism, haemorrhage and endocarditis, as well as structural valve deterioration and future re-operation with conventional valve replacement, particularly in younger populations. Furthermore, over the preceding two decades, our greater understanding of the functional anatomy of the BAV, pathophysiological mechanisms of BAV insufficiency and the development of a functional classification of aortic regurgitation have significantly contributed to the evolution of aortic valve reconstructive surgery. In this commentary, we discuss a recent article from the Journal of Cardiac Surgery comparing external annuloplasty and subcommissural annuloplasty as techniques for BAV repair.

The structure of a protein plays a pivotal role in determining its function. Often, the protein surface’s shape and curvature dictate its nature of interaction with other proteins and biomolecules. However, marked by corrugations and roughness, a protein’s surface representation poses significant challenges for its curvature-based characterization. In the present study, we employ unsupervised machine learning to segment the protein surface into patches. To measure the surface curvature of a patch, we present an algebraic sphere fitting method that is fast, accurate, and robust. Moreover, we use local curvatures to show the existence of “shape complementarity” in protein-protein, antigen-antibody, and protein-ligand interfaces. We believe that the current approach could help understand the relationship between protein structure and its biological function and can be used to find binding partners of a given protein.