Correlations between the alpha-Gal antigen, antibody response and calcification of cardiac valve bioprostheses: experimental evidence obtained using an alpha-Gal knockout mouse animal model

IntroductionPreformed antibodies against αGal in the human and the presence of αGal antigens on the tissue constituting the commercial bioprosthetic heart valves (BHVs, mainly bovine or porcine pericardium), lead to opsonization of the implanted BHV, leading to deterioration and calcification. Murine subcutaneous implantation of BHVs leaflets has been widely used for testing the efficacy of anti-calcification treatments. Unfortunately, commercial BHVs leaflets implanted into a murine model will not be able to elicit an αGal immune response because such antigen is expressed in the recipient and therefore immunologically tolerated.MethodsThis study evaluates the calcium deposition on commercial BHV using a new humanized murine αGal knockout (KO) animal model. Furtherly, the anti-calcification efficacy of a polyphenol-based treatment was deeply investigated. By using CRISPR/Cas9 approach an αGal KO mouse was created and adopted for the evaluation of the calcific propensity of original and polyphenols treated BHV by subcutaneous implantation. The calcium quantification was carried out by plasma analysis; the immune response evaluation was performed by histology and immunological assays. Anti-αGal antibodies level in KO mice increases at least double after 2 months of implantation of original commercial BHV compared to WT mice, conversely, the polyphenols-based treatment seems to effectively mask the antigen to the KO mice’s immune system.ResultsCommercial leaflets explanted after 1 month from KO mice showed a four-time increased calcium deposition than what was observed on that explanted from WT. Polyphenol treatment prevents calcium deposition by over 99% in both KO and WT animals. The implantation of commercial BHV leaflets significantly stimulates the KO mouse immune system resulting in massive production of anti-Gal antibodies and the exacerbation of the αGal-related calcific effect if compared with the WT mouse. DiscussionThe polyphenol-based treatment applied in this investigation showed an unexpected ability to inhibit the recognition of BHV xenoantigens by circulating antibodies almost completely preventing calcific depositions compared to the untreated counterpart

The GENESIS (Randomized, Multicenter Study of the Pimecrolimus-Eluting and Pimecrolimus/Paclitaxel-Eluting Coronary Stent System in Patients with De Novo Lesions of the Native Coronary Arteries) Trial

ObjectivesThe aim of this study was to compare, in a randomized multicenter trial, paclitaxel-eluting stents (CoStar, Conor Medsystems, Menlo Park, California) versus pimecrolimus-eluting stents (Corio, Conor Medsystems) versus stents with dual elution of both drugs (SymBio, Conor Medsystems) in native coronary arteries.BackgroundThe CoStar cobalt-chromium reservoir-based stent platform, eluting paclitaxel in a controlled way via a bioresorbable polymer, reduces restenosis versus its respective bare-metal stent. The reservoir system allows the use of other drugs targeted to different mechanisms involved in the process of vascular restenosis and simultaneous loading of multiple, synergistic drugs.MethodsPatients with single de novo lesions were asymmetrically randomized to 1 of the 3 types of stent (1:2:2). Six-month coronary angiography was planned in all. The primary analysis was a noninferiority test for the primary end point of 6-month angiographic in-stent late lumen loss of Corio versus CoStar and SymBio versus CoStar. Secondary end points included binary angiographic restenosis and major adverse clinical events (cardiac death, myocardial infarction, target vessel revascularization).ResultsThe trial was prematurely suspended after 246 patients were enrolled (planned enrollment: 375 patients): 49 patients received CoStar, 97 received SymBio, and 100 received Corio. In-stent late loss was significantly reduced with CoStar versus either SymBio or Corio (0.58 ± 0.58 mm vs. 0.96 ± 0.73 mm and 0.58 ± 0.58 mm vs. 1.40 ± 0.67 mm, p < 0.001 for both comparisons). Binary in-stent restenosis rates were, 7.1%, 20%, and 40.9%, respectively (p < 0.001 for both comparisons); 6-month major adverse cardiac event rates were, 2.0%, 14.4%, and 39.0%, respectively (p < 0.001 for both comparisons).ConclusionsStents eluting pimecrolimus or the dual combination of pimecrolimus and paclitaxel failed to show angiographic noninferiority when compared with paclitaxel-eluting stents. (A Randomized, Multi-Center Study of the Pimecrolimus-Eluting and Pimecrolimus/Paclitaxel-Eluting Coronary Stent Systems; NCT00322569

A new device to seal large coronary aneurysms: a case report

<p>Abstract</p> <p>Introduction</p> <p>Coronary artery aneurysm is an uncommon disease. It is defined as a coronary artery dilatation, exceeding the diameter of the normal adjacent segment or the diameter of the patient's largest coronary vessel by 1.5 to 2 times. Coronary artery aneurysms are typically diagnosed by coronary angiography. The prognosis of coronary artery aneurysm is not well known and the management is challenging.</p> <p>Case presentation</p> <p>A 68-year-old Italian-Caucasian man presented to our hospital with angina. Coronary angiography revealed a large coronary aneurysm of the right coronary artery, which was successfully treated by the percutaneous implantation of an MGuard™stent.</p> <p>Conclusion</p> <p>This case report provides evidence that coronary artery aneurysms, even if very large, can be safely treated by MGuard™stent implantation. We strongly emphasize the high flexibility and good deliverability of this device, which leads to the complete exclusion of the aneurysm mediated by the process of endothelization of its thin mesh sleeves.</p

Anti-erbB2 treatment induces cardiotoxicity by interfering with cell survival pathways

INTRODUCTION: Cardiac dysfunction is among the serious side effects of therapy with recombinant humanized anti-erbB2 monoclonal antibody. The antibody blocks ErbB-2, a receptor tyrosine kinase and co-receptor for other members of the ErbB and epidermal growth factor families, which is over-expressed on the surface of many malignant cells. ErbB-2 and its ligands neuregulin and ErbB-3/ErbB-4 are involved in survival and growth of cardiomyocytes in both postnatal and adult hearts, and therefore the drug may interrupt the correct functioning of the ErbB-2 pathway. METHODS: The effect of the rat-anti-erbB2 monoclonal antibody B-10 was studied in spontaneously beating primary myocyte cultures from rat neonatal hearts. Gene expression was determined by RT-PCR (reverse transcription polymerase chain reaction) and by rat stress-specific microarray analysis, protein levels by Western blot, cell contractility by video motion analysis, calcium transients by the FURA fluorescent method, and apoptosis using the TUNEL (terminal uridine nick-end labelling) assay. RESULTS: B-10 treatment induces significant changes in expression of 24 out of 207 stress genes analyzed using the microarray technique. Protein levels of ErbB-2, ErbB-3, ErbB-4 and neuregulin decreased after 1 day. However, both transcription and protein levels of ErbB-4 and gp130 increased several fold. Calreticulin and calsequestrin were overexpressed after three days, inducing a decrease in calcium transients, thereby influencing cell contractility. Apoptosis was induced in 20% cells after 24 hours. CONCLUSION: Blocking ErbB-2 in cultured rat cardiomyocytes leads to changes that may influence the cell cycle and affects genes involved in heart functions. B-10 inhibits pro-survival pathways and reduces cellular contractility. Thus, it is conceivable that this process may impair the stress response of the heart

The Effect of Prolonged Physical Activity Performed during Extreme Caloric Deprivation on Cardiac Function

Background: Endurance exercise may induce transient cardiac dysfunction. Data regarding the effect of caloric restriction on cardiac function is limited. We studied the effect of physical activity performed during extreme caloric deprivation on cardiac function. Methods: Thirty-nine healthy male soldiers (mean age 2060.3 years) were studied during a field training exercise lasted 85– 103 hours, with negligible food intake and unlimited water supply. Anthropometric measurements, echocardiographic examinations and blood and urine tests were performed before and after the training exercise. Results: Baseline VO2 max was 5965.5 ml/kg/min. Participants ’ mean weight reduction was 5.760.9 kg. There was an increase in plasma urea (11.662.6 to 15.863.8 mmol/L, p,0.001) and urine osmolarity (6926212 to 10946140 mmol/kg, p,0.001) and a decrease in sodium levels (140.561.0 to 136.662.1 mmol/L, p,0.001) at the end of the study. Significant alterations in diastolic parameters included a decrease in mitral E wave (93.6 to 83.5 cm/s; p = 0.003), without change in E/A and E/E9 ratios, and an increase in iso-volumic relaxation time (73.9 to 82.9 ms, p = 0.006). There was no change in left or right ventricular systolic function, or pulmonary arterial pressure. Brain natriuretic peptide (BNP) levels were significantly reduced post-training (median 9 to 0 pg/ml, p,0.001). There was no elevation in Troponin T or CRP levels. On multivariate analysis, BNP reduction correlated with sodium levels and weight reduction (R = 0.8, p,0.001)

Recurrent Acute Nonrheumatic Streptococcal Myocarditis Mimicking STEMI in a Young Adult

Myocarditis consists of an inflammation of the cardiac muscle, definitively diagnosed by endomyocardial biopsy. The causal agents are primarily infectious: in developed countries, viruses appear to be the main cause, whereas in developing countries rheumatic carditis, Chagas disease, and HIV are frequent causes. Furthermore, myocarditis can be indirectly induced by an infectious agent and occurs following a latency period during which antibodies are created. Typically, myocarditis observed in rheumatic fever related to group A streptococcal (GAS) infection occurs after 2- to 3-week period of latency. In other instances, myocarditis can occur within few days following a streptococcal infection; thus, it does not fit the criteria for rheumatic fever. Myocarditis classically presents as acute heart failure, and can also be manifested by tachyarrhythmia or chest pain. Likewise, GAS-related myocarditis reportedly mimics myocardial infarction (MI) with typical chest pain, electrocardiograph changes, and troponin elevation. Here we describe a case of recurrent myocarditis, 5 years apart, with clinical presentation imitating an acute MI in an otherwise healthy 37-year-old man. Both episodes occurred 3 days after GAS pharyngitis and resolved quickly following medical treatment