BackgroundDespite timely primary percutaneous coronary intervention, coronary microvascular obstruction (CMVO) continues to limit myocardial reperfusion and worsen prognosis in patients with ST-elevation myocardial infarction (STEMI). Agonistic autoantibodies targeting the angiotensin II type 1 (AT1R) and endothelin-1 type A (ETAR) receptors have been associated with CMVO, but whether they directly contribute to microvascular injury remains unclear.MethodsWe prospectively enrolled 287 STEMI patients and evaluated CMVO, left ventricular remodeling, and major adverse cardiovascular events during a median follow-up of 460 days. Immunoglobulins were isolated from a subset of patients with the highest AT1R-AA and ETAR-AA titers and from seronegative controls. Human cardiac microvascular endothelial cells were exposed to patient-derived or control immunoglobulins, with or without pharmacological receptor blockade.ResultsPatients with higher autoantibody titers showed a greater prevalence of CMVO and worse clinical outcomes. In vitro, immunoglobulins from seropositive patients rapidly induced endothelial dysfunction, characterized by cytoskeletal disorganization, junctional disruption, endothelial activation, and increased mitochondrial oxidative stress. These alterations were most pronounced at 24 hours and progressed to reduced cell viability and increased cytotoxicity at 48 hours. Immunoglobulins from seronegative controls had no relevant effects. Blockade of AT1R and ETAR significantly mitigated endothelial injury and oxidative stress.ConclusionsAgonistic autoantibodies against AT1R and ETAR directly damage coronary microvascular endothelium and reproduce key features of CMVO observed in STEMI patients. These findings support a clinically relevant, immune-mediated mechanism of microvascular injury and suggest that receptor antagonism represents a biologically plausible, receptor-dependent mechanism warranting further investigation as a potential microvascular protective strategy in high-risk STEMI patients.

Cardiovascular diseases remain the leading cause of mortality worldwide, underscoring the urgent need for reliable in vitro models that recapitulate the complexity of the native myocardium. Conventional two-dimensional (2D) cultures lack structural and biochemical complexity, whereas in vivo models are costly, raise ethical concerns, and have poor translational potential. In this study, we developed a novel hydrogel scaffold derived from decellularized porcine ventricular myocardium (dECM). A newly optimized decellularization strategy effectively removed cellular and nuclear components while preserving essential extracellular matrix proteins. The dECM-based hydrogel exhibited reproducible self-crosslinking, gelation kinetics, and stability. Cytocompatibility assays using human bone marrow-derived mesenchymal stem cells demonstrated excellent viability and proliferation upon contact with the biomaterial. Multidimensional hydrogel applications (2.5D and 3D) in vitro revealed higher cell densities than those observed under 2D conditions. Moreover, using human umbilical vein endothelial cells, the dECM-based hydrogel proved to be a valid tool for fabricating cardiovascular in vitro models. As such, this cardiac dECM-based hydrogel is a structurally preserved, biocompatible platform that supports both short- and long-term cell culture. The scaffold has the potential to serve promising applications in cardiac tissue engineering, disease modeling, and cardiotoxicity screening by offering a closer mimicry of the native myocardial environment.

Cardiomyopathies comprise a heterogeneous group of myocardial disorders characterized by structural and/or functional abnormalities in the absence of secondary causes of myocardial dysfunction. Although genetic determinants play a central role in many forms of the disease, incomplete penetrance and the frequent absence of identifiable pathogenic variants suggest that additional mechanisms contribute to disease onset and progression. Growing evidence supports the pathogenic role of autoimmune processes in several cardiomyopathy phenotypes. A spectrum of autoantibodies targeting cardiac self-antigens, including structural proteins, intercalated disc components, intracellular proteins such as calreticulin, and G protein-coupled receptors, has been identified in affected patients. Experimental and clinical data suggest that these autoantibodies may exert functional effects on cardiomyocyte signaling pathways and intercellular coupling, thereby promoting maladaptive remodeling, progressive ventricular dysfunction, and an increased risk of arrhythmias. Accordingly, autoantibody profiling may facilitate the identification of biologically distinct cardiomyopathy subsets with potential diagnostic and prognostic implications. From a therapeutic perspective, pathogenic autoantibodies can be removed from patient serum through plasmapheresis or immunoadsorption strategies, and these approaches have been associated with improvements in hemodynamic parameters and clinical outcomes in selected patients.

Introduction: autoantibodies (AAs) activating endothelin-1 receptor type A (ETAR-AAs) and angiotensin II receptor type 1 (AT1R-AAs) are associated with microvascular obstruction, left ventricular remodeling and major adverse cardiovascular events after ST-elevation myocardial infarction (STEMI). Their association with myocardial dysfunction in the early phases after STEMI is still unknown. Hypothesis: we hypothesized ETAR-AAs and AT1R-AAs, due to their proinflammatory and profibrotic effects, are associated with myocardial dysfunction in the early phases after STEMI. Methods: we studied STEMI patients treated with primary PCI between February 2021 and April 2024 at Padua University Hospital. Blood samples for AAs level measurements were obtained within 12 h of admission. Patients were defined as seronegative or seropositive according to the AT1R-AA and ETAR-AA seropositivity threshold (>10 U/mL). Myocardial dysfunction was assessed measuring NTproBNP levels. NTproBNP levels were assessed routinely in all patients admitted for STEMI, either at admission or within 48 hours. NTproBNP levels were categorized as low/high according to the cutoff suggested for acute heart failure (300 pg/mL). We included in multivariable models measures of infarct extension and possible confounders (not including confounders which are not correlated with NTproBNP in our cohort). Results: 170 patients (median age 61 yrs, 82% males) were enrolled. Median NTproBNP was 163 pg/mL. NTproBNP was significantly correlated with ETAR-AAs (rho=0.253, p <0.001) and AT1R-AAs levels (rho=0.204, p=0.008). NTproBNP was significantly higher in ETAR-AAs seropositive (p<0.001) and in AT1R-AAs seropositive (p=0.014) patients compared to their seronegative counterparts ( Figure 1 ). At multivariable linear regression, ETAR-AAs seropositivity was independently associated with NTproBNP levels, while AT1R-AAs seropositivity was not ( Table 1 ). After multiple adjustment for all covariables reported in Table 1, ETAR-AAs positivity was associated with high NTproBNP levels (OR 5.0 (2.2-11.5), p<0.001). Conclusions: ETAR-AAs are associated with myocardial dysfunction independently from features of STEMI severity and from most common confounders. These findings suggest that ETAR-AAs can induce myocardial dysfunction irrespectively of infarct extension, possibly through a direct effect on cardiomyocytes. Further studies in individuals without a recent acute coronary syndrome are warranted.

Background:Functional autoantibodies against angiotensin II type 1 (AT1R-AAs) and endothelin-1 type A (ETAR-AAs) receptors are associated with microvascular obstruction and myocardial remodeling after ST-elevation myocardial infarction (STEMI). However, their role in the long-term prognosis after STEMI has not been investigated. Methods:This is a prospective observational study enrolling STEMI patients undergoing early primary PCI. The incidence of major adverse cardiovascular events (MACE) was investigated during the follow-up. Autoantibody seropositivity was defined as a level >10 U/ml. Results:200 STEMI patients (89% male, median age 61 years) were enrolled. 110 (55%) were seronegative for both autoantibodies, 44 (22%) were seropositive for one autoantibody, and 46 (23%) were seropositive for both autoantibodies. Over a median follow-up of 1.2 years, the incidence of MACE was higher in patients with double (31%) and single (25%) seropositivity than in seronegative patients (13%, p = 0.02 among groups). Double seropositivity was independently associated with higher risk of MACE (HR 2.386, 95% CI 1.471-3.864, p < 0.001). Conclusion:AT1R-AAs and ETAR-AAs are associated with an increased risk of MACE after STEMI. Assessment of autoantibody levels paves the way for future therapies targeting specific molecular pathways associated with poor prognosis after an acute coronary event.

The pivotal role of angiotensin II (AngII) in cardiovascular disease has been firmly established, as evidenced by a robust body of literature and the broad clinical application of AngII-inhibiting therapies. AngII type 1 receptor is the primary mediator of AngII action, and its activation initiates a multitude of cellular responses that contribute to the development of hypertension, structural changes in the heart and vasculature, and damage to target organs. This review examines AngII from a different perspective, exploring the link between the renin–angiotensin–aldosterone system and cardiovascular risk beyond hypertension, with particular emphasis on atherosclerosis development and progression.

Introduction: autoantibodies (AAs) activating angiotensin II receptor type 1 (AT1R-AAs) and endothelin-1 receptor type A (ETAR-AAs) are associated with microvascular obstruction (MVO) and major adverse cardiovascular events (MACE) after ST-elevation myocardial infarction (STEMI). Hypothesis: we hypothesized that the effect of AT1R-AAs and ETAR-AAs on MVO and MACE is stronger in patients with smaller infarct extension. Indeed, while larger infarcts are expected to face more MVO and worse prognosis, AT1R-AAs and ETAR-AAs could explain the quote of STEMI patients with smaller infarct sizes and poor outcomes. Methods: we studied STEMI patients treated with primary PCI between February 2021 and April 2024 at Padua University Hospital ( Fig A) . Blood samples for AAs level measurements were obtained within 12 h of admission. Patients were defined as seronegative, single, or double seropositive according to the AT1R-AA and ETAR-AA seropositivity (>10 U/mL). Cardiac magnetic resonance (CMR) was performed within 30 days after STEMI. Telephonic interviews and medical record revisions were performed to investigate MACE (death, myocardial reinfarction, and hospitalization for HF). Smaller or larger infarct was defined using the median infarct size in the MVO analysis and the median peak troponin level in the MACE analysis. Results: 56 patients (median age 58 yrs, 82% males) underwent CMR. The degree of seropositivity was associated with the prevalence of MVO in patients with a smaller infarct size (p=0.047), but not in those with a larger infarct size (p=0.129) ( Fig B) . A total of 174 patients (median age 61 yrs, 84% males) were investigated for incident MACE. Compared to seronegativity, double seropositivity was associated with a significantly higher risk of MACE in patients with a smaller (p=0.035), but not a larger (p=0.265), infarct extension ( Fig C). The results were confirmed after adjusting for age and infarct-related artery. Conclusions: the degree of autoantibody seropositivity was strongly correlated with MVO and MACE in patients with smaller infarct sizes, suggesting that AT1R-AAs and ETAR-AAs could play a relevant role in patients who, despite relatively small infarcts, face the adverse complications of STEMI.

Background The left ventricular remodeling (LVR) process has limited the effectiveness of therapies after myocardial infarction. The relationship between autoantibodies activating AT1R‐AAs (angiotensin II receptor type 1‐AAs) and ETAR‐AAs (autoantibodies activating endothelin‐1 receptor type A) with myocardial infarction has been described. Among patients with ST‐segment–elevation myocardial infarction, we investigated the relationship between these autoantibodies with LVR and subsequent major adverse cardiac events. Methods and Results In this prospective observational study, we included 131 patients with ST‐segment–elevation myocardial infarction (61±11 years of age, 112 men) treated with primary percutaneous coronary intervention. Within 48 hours of admission, 2‐dimensional transthoracic echocardiography was performed, and blood samples were obtained. The seropositive threshold for AT1R‐AAs and ETAR‐AAs was >10 U/mL. Patients were followed up at 6 months, when repeat transthoracic echocardiography was performed. The primary end points were LVR, defined as a 20% increase in left ventricular end‐diastolic volume index, and major adverse cardiac event occurrence at follow‐up, defined as cardiac death, nonfatal re‐myocardial infarction, and hospitalization for heart failure. Forty‐one (31%) patients experienced LVR. The prevalence of AT1R‐AAs and ETAR‐AAs seropositivity was higher in patients with versus without LVR (39% versus 11%, P<0.001 and 37% versus 12%, P=0.001, respectively). In multivariable analysis, AT1R‐AAs seropositivity was significantly associated with LVR (odds ratio [OR], 4.66; P=0.002) and represented a risk factor for subsequent major adverse cardiac events (OR, 19.6; P=0.002). Conclusions AT1R‐AAs and ETAR‐AAs are associated with LVR in patients with ST‐segment–elevation myocardial infarction. AT1R‐AAs are also significantly associated with recurrent major adverse cardiac events. These initial observations may set the stage for a better pathophysiological understanding of the mechanisms contributing to LVR and ST‐segment–elevation myocardial infarction prognosis.

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): SID 227944/22 DOR 2331157/23 Background Cardiotoxicity is the occurrence of cardiac dysfunction induced by pathophysiological stimuli as a result of toxic effects. A considerable number of drugs, including chemotherapics, antibiotics antidepressants but also antiarrhythmics, could cause an alteration of cardiac physiology, and then cardiac damage. These include disturbances in ventricular repolarization and QT interval, arrhythmias, bradycardia, tachycardia, decreases in left ventricular ejection fraction, and congestive heart failure. Precinical evaluation of drug cardiotoxicity has used animal models, which tend to be expensive, have lo throughput, and have limitations as not ever faithfully reflect the human pathophysiology, while current two-dimensional cellular models revealed to be not sufficient and specific. Purpose The aim of this study is to develop a myocardial tissue-like scaffold, in order to realize an efficient and easy-replicable in vitro model for drug cardiotoxicity prediction. This must be able to mimic the morphological, cellular, and electrophysiological complexity of the intact adult human myocardium. Material and Methods Starting from fresh porcine hearts, cardiac specimens were isolated from left ventricles using a scalpel, sectioned with a vibratome and punched with a biopsy puncher obtaining myocardial patches. Thus, samples were decellularized through a novel serial decellularization treatment based on osmotic shock and detergents. The decellularization procedure exploited a new automated, dynamic perfusion device for a standardized and optimized removal of cardiac cells and non-ECM proteins. These samples were analysed for decellularization effectiveness by DNA quantification, histology and immunofluorescence staining to evaluate cell removal and extracellular matrix integrity. Moreover, they were tested for cytocompatibility using human mesenchymal stem cells and cardiac progenitors, also derived from induced pluripotent stem cells. Cellular adhesion, behaviour, vitality, proliferation, and possible apoptotic effects were tested, too. Results In order to advance a robust bioelectronics model, an automated platform was developed to generate a three-dimensional, bioengineered replica of human myocardial tissue. With respect to the common decellularization protocol characterized by mild agitation, results based on the automated, dynamic treatments have shown a superior ability to obtain acellular, biocompatible scaffolds in terms of cell elements’ removal and extracellular matrix preservation, as well as time- and cost-effectiveness. Indeed, these decellularized scaffolds allow cell penetration, adhesion and survival. Conclusions Further experiments will be focused on evaluating functional bioengineered myocardial tissues with electrophysiological and molecular analysis to evaluate this new model's throughput capacity. Finally, the validation of these bioelectronic platforms will be performed with drugs with known cardiotoxic effects.

Abstract Background The Prognosis after ST-elevation myocardial infarction (STEMI) remains poor. Angiotensin-II and endothelin-1 contribute to adverse prognosis after STEMI through molecular mechanisms that lead to myocardial inflammation, fibrosis and, ultimately, adverse myocardial remodeling. Functional autoantibodies against angiotensin II type 1 (AT1R-AAs) and endothelin-1 type A (ETAR-AAs) receptors bind to the same receptors as natural ligands, eliciting similar (and amplified) responses. In patients with STEMI, AT1R-AAs and ETAR-AAs have been associated with a higher risk of developing microvascular obstruction and left ventricular remodeling. Both microvascular obstruction and left ventricular remodeling are associated with a poor prognosis. Purpose To assess the prognostic role of AT1R-AAs and ETAR-AAs after STEMI. Methods Consecutive STEMI patients who underwent primary percutaneous coronary intervention within 12 h after pain onset were enrolled in this prospective study. The levels of AT1R-AAs and ETAR ETAR-AAs at the time of hospital admission were measured using an enzyme-linked immunosorbent assay (ELISA) in all patients. The incidence of major adverse cardiovascular events (MACE, defined as a composite of cardiovascular mortality, myocardial re-infarction, and hospitalizations for heart failure) during follow-up was the primary outcome. Autoantibody seropositivity was defined according to ELISA’s kit manufacturer’s instructions (levels > 10 U/mL). Results Two hundred patients with STEMI were enrolled. The baseline characteristics of the patients are shown in Table 1. Of these, 110 (55%) were seronegative for both autoantibodies, 44 (22%) were seropositive for one autoantibody (but not both), and 46 (23%) were seropositive for both autoantibodies. The incidence of MACE over a 14-month median follow-up was higher in patients with double (31%) and single (25%) seropositivity than in seronegative patients (13%, p=0.009 and p=0.06, respectively). Survival free from MACE was significantly different across the different degrees of autoantibody seropositivity (Figure 1). In the multivariable Cox regression analysis, adjusted for the variables that were significant in the univariate analysis (highlighted in bold in Table 1), double seropositivity was independently associated with an increased risk of MACE (hazard ratio 2.386, 95 % CI 1.471-3.864, p<0.001). Conclusions The degree of seropositivity for AT1R-AAs and ETAR-AAs is associated with an increased risk of MACE after STEMI. Our findings provide valuable mechanistic insights into the pathophysiology of STEMI and pave the way for future therapies focused on the improvement of long-term prognosis after acute coronary syndromes.

AIMS:Spontaneous coronary artery dissection (SCAD) is an uncommon cause of acute myocardial infarction in women and has an unclear pathophysiology. Autoantibodies (AAs) targeting angiotensin-II receptor type 1 (AT1R) and endothelin-1 receptor type A (ETAR) have known detrimental effects on endothelial function. We investigated the prevalence of these AAs in SCAD-affected female patients. METHODS AND RESULTS:Female patients diagnosed at coronary angiography with myocardial infarction and SCAD were consecutively enrolled. Autoantibodies targeting angiotensin-II receptor type 1 and ETAR-AA titres and seropositivity prevalence were compared between SCAD patients, ST-elevation myocardial infarction (STEMI) patients, and healthy women. Ten women with SCAD and 20 age-matched controls (10 women with STEMI and 10 healthy women) were included. Six out of 10 (60%) women with myocardial infarction and SCAD were seropositive for AT1R-AAs and ETAR-AAs. In contrast, only one (10%) healthy woman and one (10%) STEMI patient were seropositive for AT1R-AAs (P = 0.03 and P = 0.03, respectively). One STEMI patient was seropositive for ETAR-AAs, while none of the healthy women was found to be seropositive (P = 0.03 and P = 0.01, respectively). The median AA titre was significantly higher in SCAD patients than in healthy women (P = 0.01 for AT1R-AAs; P = 0.02 for ETAR-AAs) and STEMI patients (P < 0.001 for AT1R-AAs; P = 0.002 for ETAR-AAs). CONCLUSION:Autoantibodies targeting angiotensin-II receptor type 1 and ETAR-AA seropositivity is significantly higher in SCAD women with myocardial infarction than in healthy women or female patients with STEMI. Our findings, corroborated by previous data in the literature and biological plausibility, suggest a possible role for AT1R-AAs and ETAR-AAs in the pathophysiology of SCAD in women with acute myocardial infarction and should warrant further studies with larger sample sizes.

Introduction: Spontaneous coronary artery dissection (SCAD) is an uncommon cause of myocardial infarction (MI) in women, with a still unclear pathophysiology. Autoantibodies targeting angiotensin-II receptor type 1 (AT1R) and endothelin-1 receptor type A (ETAR) (AT1R-AAs and ETAR-AAs, respectively) lead to endothelial dysfunction and have already been associated with aortic dissection. Hypothesis: We hypothesized that titers of AT1R-AAs and ETAR-AAs are higher in patients with SCAD compared to controls. Methods: Our case-control study was conducted at Padua University Hospital between January 2022 and June 2022. Female patients diagnosed at coronary angiography with MI and SCAD were consecutively enrolled. Ten women with SCAD and 20 age-matched controls (10 women with ST-elevation MI (STEMI) and 10 healthy women) were included. Serum levels for AT1R-AAs and ETAR-AAs were determined for each participant. Absolute autoantibody titers and seropositivity prevalence were compared between SCAD patients, STEMI patients, and healthy women. Seropositivity was defined according to the threshold value suggested by the manufacturer (>10 U/mL). Results: Six out of 10 (60%) women with MI and SCAD were seropositive for AT1R-AAs and ETAR-AAs. In contrast, only one (10%) healthy woman and one (10%) STEMI patient were seropositive for AT1R-AAs (p=0.03 and p=0.03, respectively). One STEMI patient was seropositive for ETAR-AAs, while none of the healthy women was found to be seropositive (p=0.03 and p=0.01, respectively). The median autoantibody titer was significantly higher in SCAD patients than in healthy women (p=0.01 for AT1R-AAs; p=0.02 for ETAR-AAs) and STEMI patients (p<0.001 for AT1R-AAs; p=0.002 for ETAR-AAs). Conclusions: AT1R-AAs and ETAR-AAs seropositivity is significantly higher in SCAD women than in healthy women or female patients with STEMI. Our findings suggest a possible role for AT1R-AAs and ETAR-AAs in the pathophysiology of SCAD in women with MI.

Due to the limited regenerative ability of cardiomyocytes, the disabling irreversible condition of myocardial failure can only be treated with conservative and temporary therapeutic approaches, not able to repair the damage directly, or with organ transplantation. Among the regenerative strategies, intramyocardial cell injection or intravascular cell infusion should attenuate damage to the myocardium and reduce the risk of heart failure. However, these cell delivery-based therapies suffer from significant drawbacks and have a low success rate. Indeed, cardiac tissue engineering efforts are directed to repair, replace, and regenerate native myocardial tissue function. In a regenerative strategy, biomaterials and biomimetic stimuli play a key role in promoting cell adhesion, proliferation, differentiation, and neo-tissue formation. Thus, appropriate biochemical and biophysical cues should be combined with scaffolds emulating extracellular matrix in order to support cell growth and prompt favorable cardiac microenvironment and tissue regeneration. In this review, we provide an overview of recent developments that occurred in the biomimetic design and fabrication of cardiac scaffolds and patches. Furthermore, we sift in vitro and in situ strategies in several preclinical and clinical applications. Finally, we evaluate the possible use of bioengineered cardiac tissue equivalents as in vitro models for disease studies and drug tests.

Introduction: No-reflow (NR), where the coronary artery is patent after treatment of ST-elevation myocardial infarction (STEMI) but tissue perfusion is not restored, is associated with worse outcome. Although several mechanisms contributing to NR have been identified, its pathophysiology is still not completely understood. Autoantibodies activating endothelin-1 receptors type A (ETAR-AAs) exert their detrimental effects through vasoconstriction, fibrosis, and inflammation. Interestingly, all these factors are also involved in NR. Hypothesis: We hypothesized that, after reopening of the epicardial coronary artery, the preexistence of ETAR-AAs might have detrimental effects on coronary microcirculation, resulting in microvascular obstruction (MVO) and, thus, NR. Methods: Our prospective study was conducted at Padua University Hospital between January 2022 and December 2022. Consecutive patients with STEMI who underwent PPCI within 6 h after the onset of symptoms were enrolled. Blood samples were obtained from all patients within 12 hours after the admission for ETAR-AAs level measurement. MVO was assessed by cardiac magnetic resonance imaging, within 15 days after successful PPCI. The seropositive threshold was provided by the manufacturer (>10 U/ml). Results: We recruited 50 patients with STEMI. MVO was observed in 24 patients (48%). ETAR-AAs were higher in patients with MVO (8.9 U/mL (interquartile range [IQR] 6.8-16.2 U/mL) vs. 5.7 U/mL [IQR 4.3-7.7 U/mL], p=0.002). The prevalence of MVO was higher in patients with ETAR-AAs seropositivity (72% vs. 38%, p=0.03). ETAR-AAs seropositivity was independently associated with MVO (OR 3.2, 95% CI 1.3-7.1; p=0.03). Conclusions: ETAR-AAs concentration are associated with MVO in STEMI patients. These findings set the stage for a better pathophysiological understanding of NR and may open new options in the management of myocardial infarction.

Department of Surgery, Anaesthesiology and Radiology, College of Veterinary Medicine, Assiut University, Assiut, Egypt, Cardiopulmonary Regenerative Engineering (CARE) Group, Centre for Biological Engineering (CBE), Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom, Department of Cardiac Thoracic Vascular Sciences and Public Health, University of Padua, Padua, Italy

EDITORIAL article Front. Cardiovasc. Med., 30 November 2022Sec. Heart Valve Disease Volume 9 - 2022 | https://doi.org/10.3389/fcvm.2022.1092102