Common and Distinctive Intercellular Communication Patterns in Human Obstructive and Nonobstructive Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy (HCM) is a common inherited disorder characterized by unexplained left ventricular hypertrophy with or without left ventricular outflow tract (LVOT) obstruction. Single-nuclei RNA-sequencing (snRNA-seq) of both obstructive and nonobstructive HCM patient samples has revealed alterations in communication between various cell types, but no direct and integrated comparison between the two HCM phenotypes has been reported. We performed a bioinformatic analysis of HCM snRNA-seq datasets from obstructive and nonobstructive patient samples to identify differentially expressed genes and distinctive patterns of intercellular communication. Differential gene expression analysis revealed 37 differentially expressed genes, predominantly in cardiomyocytes but also in other cell types, relevant to aging, muscle contraction, cell motility, and the extracellular matrix. Intercellular communication was generally reduced in HCM, affecting the extracellular matrix, growth factor binding, integrin binding, PDGF binding, and SMAD binding, but with increases in adenylate cyclase binding, calcium channel inhibitor activity, and serine-threonine kinase activity in nonobstructive HCM. Increases in neuron to leukocyte and dendritic cell communication, in fibroblast to leukocyte and dendritic cell communication, and in endothelial cell communication to other cell types, largely through changes in the expression of integrin-β1 and its cognate ligands, were also noted. These findings indicate both common and distinct physiological mechanisms affecting the pathogenesis of obstructive and nonobstructive HCM and provide opportunities for the personalized management of different HCM phenotypes.

Novel Use of the Perceval Valve for Prosthetic Aortic Valve Endocarditis Requiring Root Replacement

The surgical management of aortic valve endocarditis can be challenging. Infection with abscess formation can destroy the root and annulus, making it difficult to anchor a valve conduit. In this article, we present a novel and efficient strategy for proximal aortic reconstruction. We used a Dacron tube graft and anchored it proximally with a running suture line deep in the left ventricular outflow tract. The coronary buttons were attached, and a Perceval valve was then deployed inside the neo-root to create a bio-Bentall.

A rare cause of Right ventricular outflow tract Pseudoaneurysm in Tetralogy of Fallot

Pseudoaneurysm of the right ventricular outflow tract(RVOT) is an uncommon yet catastrophic complication after intracardiac repair of Tetralogy of Fallot(TOF). We describe a patient diagnosed with RVOT pseudoaneurysm in the immediate postoperative period after complete repair for TOF with single pulmonary artery. The pseudoaneurysm was repaired successfully. This case is reported to emphasise the importance of a high degree of suspicion of this rare entity in these patients for its early diagnosis and management.

Tissue Engineered Transcatheter Pulmonary Valved Stent Implantation: Current State and Future Prospect

Patients with the complex congenital heart disease (CHD) are usually associated with right ventricular outflow tract dysfunction and typically require multiple surgical interventions during their lives to relieve the right ventricular outflow tract abnormality. Transcatheter pulmonary valve replacement was used as a non-surgical, less invasive alternative treatment for right ventricular outflow tract dysfunction and has been rapidly developing over the past years. Despite the current favorable results of transcatheter pulmonary valve replacement, many patients eligible for pulmonary valve replacement are still not candidates for transcatheter pulmonary valve replacement. Therefore, one of the significant future challenges is to expand transcatheter pulmonary valve replacement to a broader patient population. This review describes the limitations and problems of existing techniques and focuses on decellularized tissue engineering for pulmonary valve stenting.

Hybrid Surgery for Severe Mitral Valve Calcification: Limitations and Caveats for an Open Transcatheter Approach

Background and Objectives: Mitral stenosis with extensive mitral annular calcification (MAC) remains surgically challenging in respect to clinical outcome. Prolonged surgery time with imminent ventricular rupture and systolic anterior motion can be considered as a complex of causal factors. The aim of our alternative hybrid approach was to reduce the risk of annual rupture and paravalvular leaks and to avoid obstruction of the outflow tract. A review of the current literature was also carried out. Materials and Methods: Six female patients (mean age 76 ± 9 years) with severe mitral valve stenosis and severely calcified annulus underwent an open implantation of an Edwards Sapien 3 prosthesis on cardiopulmonary bypass. Our hybrid approach involved resection of the anterior mitral leaflet, placement of anchor sutures and the deployment of a balloon expanded prosthesis under visual control. Concomitant procedures were carried out in three patients. Results: The mean duration of cross-clamping was 95 ± 31 min and cardiopulmonary bypass was 137 ± 60 min. The perioperative TEE showed in three patients an inconspicuous, heart valve-typical gradient on all implanted prostheses and a clinically irrelevant paravalvular leakage occurred in the anterior annulus. In the left ventricular outflow tract, mild to moderately elevated gradients were recorded. No adverse cerebrovascular events and pacemaker implantations were observed. All but one patient survived to discharge. Survival at one year was 83.3%. Conclusions: This “off label” implantation of the Edwards Sapien 3 prosthesis may be considered as a suitable bail-out approach for patients at high-risk for mitral valve surgery or deemed inoperable due to extensive MAC.

Effect of 3D-Printed Hearts Used in Left Ventricular Outflow Tract Obstruction: A Multicenter Study

Objective:The purpose of this research was to explore the application value of a three-dimensional (3D)-printed heart in the operation for left ventricular outflow tract (LVOT) obstruction. Methods: From August 2019 to October 2021, 46 patients with LVOT obstruction underwent surgical treatment at Peking University International Hospital, Southwest Medical University Affiliated Hospital of Traditional Chinese Medicine and Guangyuan First People's Hospital. According to the treatment method, 22 cases were allocated to the experimental group and 24 cases to the control group . The operation time, cardiopulmonary bypass time, intraoperative blood loss, hospitalization time, postoperative ejection fraction (EF), left ventricular flow velocity (LVFV), LVOT pressure difference (LVP), postoperative interventricular septal thickness (IST), inner diameter of the left ventricular outflow tract (IDLV), systolic anterior motion (SAM), atrioventricular block rate, aortic regurgitation (AR) rate and surgical complication rate of the two groups were compared. Results: The operation time, cardiopulmonary bypass time, intraoperative blood loss, hospitalization time, LVP, postoperative IST, AR, SAM, and postoperative LVFV of the experimental group were significantly lower than those of the control group (P < 0.05). The IDLV was larger than that of the control group (P < 0.05). There was no significant difference in the postoperative EF, atrioventricular block rate or complication rate between the two groups (P > 0.05). Conclusion: A 3D-printed heart model for in vitro simulation surgery is conducive to formulating a more reasonable surgical plan and reducing surgical trauma and operation time, thereby promoting the recovery and maintenance of the heart.

Image-Based Computational Hemodynamics Analysis of Systolic Obstruction in Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy (HCM) is a pathological condition characterized by an abnormal thickening of the myocardium. When affecting the medio-basal portion of the septum, it is named Hypertrophic Obstructive Cardiomyopathy (HOCM) because it induces a flow obstruction in the left ventricular outflow tract. In any type of HCM, the myocardial function can become compromised, possibly resulting in cardiac death. In this study, we investigated with computational analysis the hemodynamics of patients with different types of HCM. The aim was quantifying the effects of this pathology on the intraventricular blood flow and pressure gradients, and providing information potentially useful to guide the indication and the modality of the surgical treatment (septal myectomy). We employed an image-based computational approach, integrating fluid dynamics simulations with geometric and functional data, reconstructed from standard cardiac cine-MRI acquisitions. We showed that with our approach we can better understand the patho-physiological behavior of intraventricular blood flow dynamics due to the abnormal morphological and functional aspect of the left ventricle. The main results of our investigation are: (a) a detailed patient-specific analysis of the blood velocity, pressure and stress distribution associated to HCM; (b) a computation-based classification of patients affected by HCM that can complement the current clinical guidelines for the diagnosis and treatment of HOCM.