Predicting and Recognizing Drug-Induced Type I Brugada Pattern Using ECG-Based Deep Learning

BACKGROUND

Brugada syndrome (BrS) has been associated with sudden cardiac death in otherwise healthy subjects, and drug-induced BrS accounts for 55% to 70% of all patients with BrS. This study aims to develop a deep convolutional neural network and evaluate its performance in recognizing and predicting BrS diagnosis.

METHODS AND RESULTS

Consecutive patients who underwent ajmaline testing for BrS following a standardized protocol were included. ECG tracings from baseline and during ajmaline were transformed using wavelet analysis and a deep convolutional neural network was separately trained to (1) recognize and (2) predict BrS type I pattern. The resultant networks are referred to as BrS-Net. A total of 1188 patients were included, of which 361 (30.3%) patients developed BrS type I pattern during ajmaline infusion. When trained and evaluated on ECG tracings during ajmaline, BrS-Net recognized a BrS type I pattern with an AUC-ROC of 0.945 (0.921-0.969) and an AUC-PR of 0.892 (0.815-0.939). When trained and evaluated on ECG tracings at baseline, BrS-Net predicted a BrS type I pattern during ajmaline with an AUC-ROC of 0.805 (0.845-0.736) and an AUC-PR of 0.605 (0.460-0.664).

CONCLUSIONS

BrS-Net, a deep convolutional neural network, can identify BrS type I pattern with high performance. BrS-Net can predict from baseline ECG the development of a BrS type I pattern after ajmaline with good performance in an unselected population.

Acute Aortic Syndromes from Diagnosis to Treatment-A Comprehensive Review

This work aims to provide a comprehensive description of the characteristics of a group of acute aortic diseases that are all potentially life-threatening and are collectively referred to as acute aortic syndromes (AASs). There have been recent developments in the care and diagnostic plan for AAS. A substantial clinical index of suspicion is required to identify AASs before irreversible fatal consequences arise because of their indefinite symptoms and physical indicators. A methodical approach to the diagnosis of AAS is addressed. Timely and suitable therapy should be started immediately after diagnosis. Improving clinical outcomes requires centralising patients with AAS in high-volume centres with high-volume surgeons. Consequently, the management of these patients benefits from the increased use of aortic centres, multidisciplinary teams and an "aorta code". Each acute aortic entity requires a different patient treatment strategy; these are outlined below. Finally, numerous preventive strategies for AAS are discussed. The keys to good results are early diagnosis, understanding the natural history of these disorders and, where necessary, prompt surgical intervention. It is important to keep in mind that chest pain does not necessarily correspond with coronary heart disease and to be alert to the possible existence of aortic diseases because once antiplatelet drugs are administered, a blocked coagulation system can complicate aortic surgery and affect prognosis. The management of AAS in "aortic centres" improves long-term outcomes and decreases mortality rates.

Inflammatory Status Assessment by Machine Learning Techniques to Predict Outcomes in Patients with Symptomatic Aortic Stenosis Treated by Transcatheter Aortic Valve Replacement

(1) Background: Although transcatheter aortic valve replacement (TAVR) significantly improves long-term outcomes of symptomatic severe aortic stenosis (AS) patients, long-term mortality rates are still high. The aim of our study was to identify potential inflammatory biomarkers with predictive capacity for post-TAVR adverse events from a wide panel of routine biomarkers by employing ML techniques. (2) Methods: All patients diagnosed with symptomatic severe AS and treated by TAVR since January 2016 in a tertiary center were included in the present study. Three separate analyses were performed: (a) using only inflammatory biomarkers, (b) using inflammatory biomarkers, age, creatinine, and left ventricular ejection fraction (LVEF), and (c) using all collected parameters. (3) Results: A total of 338 patients were included in the study, of which 56 (16.5%) patients died during follow-up. Inflammatory biomarkers assessed using ML techniques have predictive value for adverse events post-TAVR with an AUC-ROC of 0.743 and an AUC-PR of 0.329; most important variables were CRP, WBC count and Neu/Lym ratio. When adding age, creatinine and LVEF to inflammatory panel, the ML performance increased to an AUC-ROC of 0.860 and an AUC-PR of 0.574; even though LVEF was the most important predictor, inflammatory parameters retained their value. When using the entire dataset (inflammatory parameters and complete patient characteristics), the ML performance was the highest with an AUC-ROC of 0.916 and an AUC-PR of 0.676; in this setting, the CRP and Neu/Lym ratio were also among the most important predictors of events. (4) Conclusions: ML models identified the CRP, Neu/Lym ratio, WBC count and fibrinogen as important variables for adverse events post-TAVR.

The Gender Gap in Aortic Dissection: A Prospective Analysis of Risk and Outcomes

Aortic dissection (AD) is a severe cardiovascular condition that could have negative consequences. Our study employed a prospective design and examined preoperative, perioperative, and postoperative data to evaluate the effects of gender on various medical conditions. We looked at how gender affected the results of aortic dissection (AD). In contrast to female patients who had more systemic hypertension (p=0.031), male patients had higher rates of hemopericardium (p=0.003), pulmonary hypertension (p=0.039), and hemopericardium (p=0.003). Dobutamine administration during surgery significantly raised the mortality risk (p=0.015). There were noticeably more women patients (p=0.01) in the 71 to 80 age group. Significant differences in age (p=0.004), eGFR at admission (p=0.009), and eGFR at discharge (p=0.006) were seen, however, there was no association between gender and mortality. In conclusion, our findings highlight that gender may no longer be such an important aspect of aortic dissection disease as we previously thought, and this information could have an important contribution for surgeons as well as for anesthesiologists involved in the management of acute aortic dissection.

Staphylococcus-induced proliferative glomerulonephritis and cerebral hemorrhage - fatal complications in a young female with postpartum cardiomyopathy and an implanted left ventricular assist device: a case report and review of the literature

Background: The continuous-flow left ventricular assist device (CF-LVAD) is used to save the lives of patients in the final stage of congestive heart failure, replacing the pump function of the left ventricle. Although quality of life increases significantly, CF-LVAD-related complications might prove fatal, as in the case presented in this paper.Methods: A 20-year-old female, during her second pregnancy, presented with signs of heart failure. Emergency caesarean section was necessary to save the baby, but peripartum cardiomyopathy developed in the mother. The use of an implantable cardioverter-defibrillator (ICD) was necessary 5 years later. As the clinical progression was unfavorable under medical treatment, with the patient reaching INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) Profile 1 (refractory cardiogenic shock), the treatment of choice was the implantation of a CF-LVAD.Results: After 3 years of follow-up (at the age of 28), the patient presented with a positive hemoculture for Staphylococcus aureus. Prolonged antibiotic therapy and attentive follow-up was prescribed. Although an effective antiplatelet and anticoagulant treatment was applied, and despite therapeutic values of prothrombin time and international normalized ratio (INR), the patient died as result of a fatal cerebral hemorrhage. The autopsy also revealed septic emboli, disseminated intravascular coagulation, and focal proliferative glomerulonephritis.Conclusions: Although the benefits of CF-LVAD are significant, bleeding episodes can be severe and LVAD-associated infection can trigger glomerular injury and increase mortality.

Preclinical Testing of Living Tissue-Engineered Heart Valves for Pediatric Patients, Challenges and Opportunities

Introduction: Pediatric patients with cardiac congenital diseases require heart valve implants that can grow with their natural somatic increase in size. Current artificial valves perform poorly in children and cannot grow; thus, living-tissue-engineered valves capable of sustaining matrix homeostasis could overcome the current drawbacks of artificial prostheses and minimize the need for repeat surgeries. Materials and Methods: To prepare living-tissue-engineered valves, we produced completely acellular ovine pulmonary valves by perfusion. We then collected autologous adipose tissue, isolated stem cells, and differentiated them into fibroblasts and separately into endothelial cells. We seeded the fibroblasts in the cusp interstitium and onto the root adventitia and the endothelial cells inside the lumen, conditioned the living valves in dedicated pulmonary heart valve bioreactors, and pursued orthotopic implantation of autologous cell-seeded valves with 6 months follow-up. Unseeded valves served as controls. Results: Perfusion decellularization yielded acellular pulmonary valves that were stable, no degradable in vivo, cell friendly and biocompatible, had excellent hemodynamics, were not immunogenic or inflammatory, non thrombogenic, did not calcify in juvenile sheep, and served as substrates for cell repopulation. Autologous adipose-derived stem cells were easy to isolate and differentiate into fibroblasts and endothelial-like cells. Cell-seeded valves exhibited preserved viability after progressive bioreactor conditioning and functioned well in vivo for 6 months. At explantation, the implants and anastomoses were intact, and the valve root was well integrated into host tissues; valve leaflets were unchanged in size, non fibrotic, supple, and functional. Numerous cells positive for a-smooth muscle cell actin were found mostly in the sinus, base, and the fibrosa of the leaflets, and most surfaces were covered by endothelial cells, indicating a strong potential for repopulation of the scaffold. Conclusions: Tissue-engineered living valves can be generated in vitro using the approach described here. The technology is not trivial and can provide numerous challenges and opportunities, which are discussed in detail in this paper. Overall, we concluded that cell seeding did not negatively affect tissue-engineered heart valve (TEHV) performance as they exhibited as good hemodynamic performance as acellular valves in this model. Further understanding of cell fate after implantation and the timeline of repopulation of acellular scaffolds will help us evaluate the translational potential of this technology.

The VALVE REGEN project. Developing an innovative tissue engineered heart valve, in vitro and in vivo testing – preliminary results

Background

Regenerative Medicine and Tissue Engineering are the grounds on which multidisciplinary teams aspire to obtain the perfect valvular substitute, which overcomes shortcomings of the present prostheses.

Purpose

Was to obtain a tissue engineered heart valve (TEHV) by repopulating with valvular resident cells – endothelial (EC) and fibroblasts (FB) a decellularized heart valve scaffold. Then their functionality and behavior was assessed in vitro and in vivo.

Methods

This study is part of a research grant approved by the Ethics Committee of the University. Six ovine pulmonary valves underwent a perfusion based decellularization protocol. Using a sequence of chemical and enzymatic treatment under a pressure gradient, cell removal was achieved and attested by histological investigations (DAPI nuclear staining –4',6-diamidino-2-phenylindol and haematoxylin-eosin) and DNA extraction. Ovine sub-dermal adipose tissue was harvested followed by stem cells isolation and culture. Using Endothelial Cell Growth Supplement and mechanical stimuli EC were differentiated and with Transforming Growth Factor-B1, FB were obtained. FB were internally seeded into cuspis bases using a 22 gauge needle and externally on the adventitia by using a rotator allowing a uniform distribution and seeding of cells. EC were seeded into leaflets pockets and intra-luminal also using the rotator. The repopulated valves were preconditionated in a bioreactor by gradually exposing them to the pulmonary hemodynamic regimen. By using a high speed camera, their behavior was examined when exposed to in vivo conditions. The in vivo testing was performed by surgical implantation in the gold model considered animal – the sheep. By transesophageal ultrasound (TEE US) and epicardic US, their intra-operatory function was evaluated. Post-procedure, evaluation was performed by periodic trans-thoracic (TTE US).

Results

Six TEHV were obtained. The decellularization histology assessment revealed acellular scaffolds and non-detectable nucleic material at the DNA extraction. Six adipose derived stem cells cultures were obtained and subsequently specialized towards EC and FB lines. The repopulation procedures underwent without incidents. During the bioreactor preconditioning, the TEHV showed complete opening and competent central coaptation. Leaflets presented physiological movement and absence of damage of valvular apparatus. The TEE US evaluation in vivo revealed normal valvular function without signs of stenosis or regurgitation. The periodic TTE US showed preserved valvular function.

Conclusions

Our preliminary results point out a manufactured TEHV with physiological behavior when tested in vitro and in vivo. Their interaction with a living body will be pointed out only in the explant phase, after histology analysis. The present results appear optimistic but only extended studies and follow-ups will certify their superiority in terms of performances and behavior.

Funding Acknowledgement

Type of funding source: Public grant(s) – EU funding. Main funding source(s): This paper was financed by a grant from the Competitiveness Operational Programme 2014-2020, Tissue engineering technologies for cardiac valve regeneration, valve-regen, id P_37_673, Mysmis code: 103431, contract 50/05.09.2016.

Different Manifestations in Familial Isolated Left Ventricular Non-compaction: Two Case Reports and Literature Review

Left ventricular non-compaction (LVNC) is a form of cardiomyopathy characterized by prominent trabeculae and deep intertrabecular recesses which form a distinct "non-compacted" layer in the myocardium. It results from intrauterine arrest of the compaction process of the left ventricular myocardium. Clinical manifestations vary from asymptomatic to heart failure (HF), arrhythmias, or thromboembolic events. We present a case of mother and son diagnosed with isolated LVNC (ILVNC). A 4-years-old male patient, diagnosed at 3 months with ILVNC, and NYHA functional class IV HF, was admitted to the Emergency Institute for Cardiovascular Diseases and Transplantation of Targu Mures, Romania, for cardiologic reevaluation, and diagnosis confirmation. ILVNC was confirmed using echocardiography, revealing a non-compaction to compaction (NC/C) ratio of > 2.7. His evolution was stationary until the age of 8 years, when severe pneumonia caused hemodynamic decompensation, and he was listed for heart transplantation (HT). The patient underwent HT at the age of 11 years with favorable postoperative outcome. Meanwhile, a 22-years-old female patient, mother of the aforementioned patient, was also admitted to our institute due to severe fatigue, dyspnea, and recurrent palpitations with multiple implantable cardioverter defibrillator (ICD) shock delivery. Extensive medical history revealed that a presumptive ILVNC diagnosis was established when she was 11 years old. She was asymptomatic until 18 years old, when 3 months post-partum, she developed NYHA functional class III HF, and subsequently underwent ICD implantation. Her diagnosis was confirmed using multi-detector computed tomography angiography, which revealed a NC/C ratio of > 3.3. ICD adjustments were carried out with a favorable evolution under chronic drug therapy. The last evaluation, at 27 years old, revealed that she was in NYHA functional class II HF. In conclusion, ILVNC, even when familial, can present different clinical pictures and therefore requires different medical approaches.

Therapeutic Management of Trauma-related Acute Pancreatitis in a Heart Transplant Recipient

Acute pancreatitis is a very mortal disease, mortality that increases even more in patients with cardiac transplantation. Medical-surgical management of acute pancreatitis in transplanted patients can make the difference between life and death. The aim of this paper was to highlight the severity of this pathology especially because the patient is immunosuppressed after cardiac transplant. A case of 36-year-old man, known with heart transplant, immunosuppressive treatment and chronic renal frailer, who arrived to Emergency Department, with severe abdominal pain and abdominal distention which started after a traumatic accident. Investigations revealed acute pancreatitis that needed three surgeries for acute necrotic hemorrhagic pancreatitis, acute bleeding, left subphrenic abscess and intensive care therapy. With favorable postoperative evolution, patient is discharged 60 days later He�s follow up reveled no gastrointestinal or cardiac complication with an improved quality of life.

Successful Surgical Treatment of a Giant Left Ventricular Aneurysm

Left ventricular anevrysm (LVA) is the effect of left ventricular (LV) remodeling after myocardial infarction (MI). The surgical technique to improve cardiac function is geometric reconstruction of the LV. The aim of this paper is to highlight the importance of restoring left ventricle geometry. We report a case of 53 year-old man, without any known cardiovascular history, with acute anterior myocardial infarction, left ventricular aneurysm and massive left ventricular thrombus, who arrived into the emergency department 24 hours after the onset of symptomatology. After hemodynamic stabilization, we performed geometric reconstruction of the left ventricle. With favorable postoperative evolution, patient is discharged 14 days later. At the periodic checkups it is noted that he�s postoperative ejection fraction (EF) improved and also the quality of life.

Minimally Invasive Surgical Protocol for Adipose Derived Stem Cells Collection and Isolation - Ovine Model

Many methods of stem cells collection and isolation from various tissue types harvested either from small or large experimental animals or from human tissues have been published so far, all evaluating them as a potential source of adult mesenchymal stem cells with applicability in various pathologies or tissue bioengineering. The present study purposed to describe a minimally invasive surgical protocol for adipose tissue collection from sheep�s inter-scapular area. The procedure was carried out on adult sheeps, in aseptic conditions. A light sedation protocol with Detomidine was performed, the recovery from anesthesia being carried out with Atipamezole. Throughout the sedation, the surgical procedure and the recovery from anesthesia, the vital functions of the animal were monitored. The adipose tissue samples collected in sterile tubes with culture medium (Dulbecco�s modified Eagle�s medium - DMEM/10% / FBS10 - fetal bovine serum, 2% antibiotic/antifungal), have been succesfully used by our research team for adipose tissue derived stem cells (ADSCs) isolation for further use in cardiac valves tissue engineering.

[Surgical ventricular reconstruction for ischemic left ventricular aneurysm. Early and medium-term outcomes for two surgical techniques]

INTRODUCTION

Left ventricular aneurysm is a severe complication of acute myocardial infarction, which contributes significantly to mortality and morbidity associated with this pathology. Despite the progress of correction techniques, there are still controversies about the optimal approach addressing this pathology.

AIM

The aim of this study was to analyse short and medium term outcomes of left ventricular reconstruction for ischemic left ventricular aneurysm using two surgical techniques (endoventricular patch plasty and liniar suture) in order to determine if one of these techniques has supperior results.

METHOD

117 patients were included in the study, 48 patients (41%) underwent left ventricular reconstruction with endoventricular patch (Group 1), 69 patients (59%; Group 2) had linear reconstruction. 113 patients (96.5%) required associated procedures: 108 surgical myocardial revascularization, 18 mitral valvuloplasty and 8 ventricular septal defect closure. Short and medium term morbidity, mortality, alteration of ejection fraction and NYHA class were analysed.

RESULTS

Perioperative mortality was 11.11%, 4.2% in the endoventricular patch group, and 15.9% in the linear suture group (p = 0.03). The overall 5-year survival was 78.5% (88.7% in Group 1 and 71.2% in Group 2). The left ventricular ejection fraction and NYHA functional class improved in both groups, with greater improvement in the endoventricular patch group.

CONCLUSIONS

Surgical ventricular reconstruction is a procedure performed for the correction of ischemic left ventricular aneurysm with good early and medium-term results, but with better results with the endoventricular patch technique regarding early and medium-term mortality, ejection fraction and NYHA functional class improvement. Orv Hetil. 2018; 159(51): 2167-2174.

A Standardized Dissection Protocol to Generate Aortic Valvular Scaffolds from Porcine Hearts

OBJECTIVE

To describe a particular harvesting procedure for isolating intact porcine aortic heart valve roots as potential sources for biologic scaffolds.

METHODS

Fresh porcine hearts were brought to the Tissue Engineering and Regenerative Medicine Laboratory at the University of Medicine and Pharmacy in Targu Mures. The aortic roots were extracted from the porcine hearts by anatomical dissection. For this purpose, we used a basic surgical instrument kit. This initial phase was the first step in obtaining acellular extracellular matrix as a biologic scaffold material.

RESULTS

Aortic roots were isolated with preservation of the ascending aorta as well as the intact aortic sinus and coronaries together with the adjacent myocardial tissue and anterior leaflet of the mitral valve. This approach allowed for safe mounting of roots into mounting rings for perfusion decellularization.

CONCLUSIONS

The described procedure is a feasible protocol for obtaining intact biological valvular scaffolds from porcine hearts. Reduced requirements regarding tools and personnel underline the easiness of aortic root harvesting using this particular procedure.

Bioreactor Conditioning of Valve Scaffolds Seeded Internally with Adult Stem Cells

The goal of this study was to test the hypothesis that stem cells, as a response to valve-specific extracellular matrix "niches" and mechanical stimuli, would differentiate into valvular interstitial cells (VICs). Porcine aortic root scaffolds were prepared by decellularization. After verifying that roots exhibited adequate hemodynamics in vitro, we seeded human adipose-derived stem cells (hADSCs) within the interstitium of the cusps and subjected the valves to in vitro pulsatile bioreactor testing in pulmonary pressures and flow conditions. As controls we incubated cell-seeded valves in a rotator device which allowed fluid to flow through the valves ensuring gas and nutrient exchange without subjecting the cusps to significant stress. After 24 days of conditioning, valves were analyzed for cell phenotype using immunohistochemistry for vimentin, alpha-smooth muscle cell actin (SMA) and prolyl-hydroxylase (PHA). Fresh native valves were used as immunohistochemistry controls. Analysis of bioreactor-conditioned valves showed that almost all seeded cells had died and large islands of cell debris were found within each cusp. Remnants of cells were positive for vimentin. Cell seeded controls, which were only rotated slowly to ensure gas and nutrient exchange, maintained about 50% of cells alive; these cells were positive for vimentin and negative for alpha-SMA and PHA, similar to native VICs. These results highlight for the first time the extreme vulnerability of hADSCs to valve-specific mechanical forces and also suggest that careful, progressive mechanical adaptation to valve-specific forces might encourage stem cell differentiation towards the VIC phenotype.

Functional Heart Valve Scaffolds Obtained by Complete Decellularization of Porcine Aortic Roots in a Novel Differential Pressure Gradient Perfusion System

There is a great need for living valve replacements for patients of all ages. Such constructs could be built by tissue engineering, with perspective of the unique structure and biology of the aortic root. The aortic valve root is composed of several different tissues, and careful structural and functional consideration has to be given to each segment and component. Previous work has shown that immersion techniques are inadequate for whole-root decellularization, with the aortic wall segment being particularly resistant to decellularization. The aim of this study was to develop a differential pressure gradient perfusion system capable of being rigorous enough to decellularize the aortic root wall while gentle enough to preserve the integrity of the cusps. Fresh porcine aortic roots have been subjected to various regimens of perfusion decellularization using detergents and enzymes and results compared to immersion decellularized roots. Success criteria for evaluation of each root segment (cusp, muscle, sinus, wall) for decellularization completeness, tissue integrity, and valve functionality were defined using complementary methods of cell analysis (histology with nuclear and matrix stains and DNA analysis), biomechanics (biaxial and bending tests), and physiologic heart valve bioreactor testing (with advanced image analysis of open-close cycles and geometric orifice area measurement). Fully acellular porcine roots treated with the optimized method exhibited preserved macroscopic structures and microscopic matrix components, which translated into conserved anisotropic mechanical properties, including bending and excellent valve functionality when tested in aortic flow and pressure conditions. This study highlighted the importance of (1) adapting decellularization methods to specific target tissues, (2) combining several methods of cell analysis compared to relying solely on histology, (3) developing relevant valve-specific mechanical tests, and (4) in vitro testing of valve functionality.