Left bundle branch area versus conventional pacing after transcatheter valve implant for aortic stenosis: the LATVIA study.

BACKGROUND: Atrioventricular block (AVB) is a frequent complication in patients undergoing transcatheter aortic valve implantation (TAVI). Right apex ventricular pacing (RVP) represents the standard treatment but may induce cardiomyopathy over the long term. Left bundle branch area pacing (LBBAP) is a promising alternative, minimizing the risk of desynchrony. However, available evidence with LBBAP after TAVI is still low. OBJECTIVE: To assess the feasibility and safety of LBBAP for AVB post-TAVI compared with RVP. METHODS: Consecutive patients developing AVB early after TAVI were enrolled between 1 January 2022 and 31 December 2022 at three high-volume hospitals and received LBBAP or RVP. Data on procedure and at short-term follow-up (at least 3 months) were collected. RESULTS: A total of 38 patients (61% men, mean age 83 ±â€Š6 years) were included; 20 patients (53%) received LBBAP. Procedural success was obtained in all patients according to chosen pacing strategy. Electrical pacing performance at implant and after a mean follow-up of 4.2 ±â€Š2.8 months was clinically equivalent for both pacing modalities. In the LBBAP group, procedural time was longer (70 ±â€Š17 versus 58 ±â€Š15 min in the RVP group, P = 0.02) and paced QRS was shorter (120 ±â€Š19 versus 155 ±â€Š12 ms at implant, P < 0.001; 119 ±â€Š18 versus 157 ±â€Š9 ms at follow-up, P < 0.001). Complication rates did not differ between the two groups. CONCLUSION: In patients with AVB after TAVI, LBBAP is feasible and safe, resulting in a narrow QRS duration, either acutely and during the follow-up, compared with RVP. Further studies are needed to evaluate if LBBAP reduces pacing-induced cardiomyopathy in this clinical setting.

Harnessing RNA Technology to Advance Therapeutic Vaccine Antigens against Chagas Disease.

Chagas disease (CD) (American trypanosomiasis caused by Trypanosoma cruzi) is a parasitic disease endemic in 21 countries in South America, with increasing global spread. When administered late in the infection, the current antiparasitic drugs do not prevent the onset of cardiac illness leading to chronic Chagasic cardiomyopathy. Therefore, new therapeutic vaccines or immunotherapies are under development using multiple platforms. In this study, we assessed the feasibility of developing an mRNA-based therapeutic CD vaccine targeting two known T. cruzi vaccine antigens (Tc24─a flagellar antigen and ASP-2─an amastigote antigen). We present the mRNA engineering steps, preparation, and stability of the lipid nanoparticles and evaluation of their uptake by dendritic cells, as well as their biodistribution in c57BL/J mice. Furthermore, we assessed the immunogenicity and efficacy of two mRNA-based candidates as monovalent and bivalent vaccine strategies using an in vivo chronic mouse model of CD. Our results show several therapeutic benefits, including reductions in parasite burdens and cardiac inflammation, with each mRNA antigen, especially with the mRNA encoding Tc24, and Tc24 in combination with ASP-2. Therefore, our findings demonstrate the potential of mRNA-based vaccines as a therapeutic option for CD and highlight the opportunities for developing multivalent vaccines using this approach.

Arrhythmogenic Cardiomyopathy: Definition, Classification and Arrhythmic Risk Stratification.

Arrhythmogenic cardiomyopathy (ACM) is a heart disease characterized by a fibrotic replacement of myocardial tissue and a consequent predisposition to ventricular arrhythmic events, especially in the young. Post-mortem studies and the subsequent diffusion of cardiac MRI have shown that left ventricular involvement in arrhythmogenic cardiomyopathy is common and often develops early. Regarding the arrhythmic risk stratification, the current scores underestimate the arrhythmic risk of patients with arrhythmogenic cardiomyopathy with left involvement. Indeed, the data on arrhythmic risk stratification in this group of patients are contradictory and not exhaustive, with the consequence of not correctly identifying patients at a high arrhythmic risk who deserve protection from arrhythmic death. We propose a literature review on arrhythmic risk stratification in patients with ACM and left involvement to identify the main features associated with an increased arrhythmic risk in this group of patients.

Cost-utility of cardiac contractility modulation in patients with heart failure with reduced ejection fraction in Italy.

AIMS: Cardiac contractility modulation (CCM) is a device therapy for heart failure, based on the delivery of high-voltage biphasic impulses to the right ventricular septum during the myocardial absolute refractory period. This study evaluated the cost-effectiveness of CCM therapy plus optimal medical therapy (OMT) vs. OMT alone in patients with heart failure with reduced ejection fraction. METHODS AND RESULTS: A Markov model with a lifespan time horizon was developed to assess the cost-utility using the FIX trials as main data sources. A deterministic sensitivity analysis and a probabilistic sensitivity analysis were run to analyse the decision uncertainty in the model through cost-effectiveness acceptability curve (CEAC) and cost-effectiveness acceptability frontier (CEAF). Value of information analysis was also conducted computing the expected value of perfect information (EVPI) and the expected value of partial perfect information. The base case results showed that the CCM plus OMT option was highly cost-effective compared with OMT alone with an incremental cost-utility ratio of €7034/quality-adjusted life year (QALY). The CEAC and CEAF illustrated that for all willingness to pay levels above €5600/QALY, tested up to €50 000/QALY, CCM plus OMT alternative had the highest probability of being cost-effective. The EVPI per patient was estimated to be €124 412 on a willingness to pay threshold of €30 000/QALY. CONCLUSIONS: For patients with heart failure with reduced ejection fraction, CCM therapy could be cost-effective when taking a lifetime horizon. Further long-term, post-approval clinical studies are needed to verify these results in a real-world context, particularly concerning the effect of CCM therapy on mortality.

Left Atrial Appendage Occlusion in Patients with Failure of Antithrombotic Therapy: Good Vibes from Early Studies.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and predisposes patients to an increased risk of cardioembolic events (CE), such as ischemic stroke, TIA, or systemic embolism [...].

Left Bundle Branch Area Pacing over His Bundle Pacing: How Far Have We Come?

Implantable cardiac pacemakers have greatly evolved during the few past years, focusing on newer modalities of physiologic cardiac pacing [...].

Optimization of a detergent-based protocol for membrane proteins purification from mammalian cells.

Membrane proteins constitute around 20-30 % of the proteins encoded by mammalian genes, are involved in many cell functions, and represent the majority of drug targets. However, the isolation of membrane proteins is challenging because of their partial hydrophobicity, requiring detergents to extract them from cell membranes and stabilize them in solution. Many commercial kits use this principle, but they are expensive, and their chemical composition is not known. In this work, we propose a fast, detergent-based protocol for the purification of membrane proteins from murine and human cells. This protocol is based on three steps: cell washing to remove cell culture medium proteins, cells permeabilization using digitonin to remove the intracellular components, and cell membranes disruption using Triton X-100 to solubilize membrane proteins and keep them in solution. We measured the total protein yield using our protocol with two different detergent concentrations and compared it to a commercial kit. We further assessed membrane protein enrichment by comparing markers for specific cellular components using SDS-PAGE/western blot and identifying specific proteins by qualitative mass spectrometry. Our protocol led to a final protein yield analogous to the commercial kit and similar membrane protein purity, while resulting significantly cheaper compared to the commercial kit. Furthermore, this process can be applied to a different number and types of cells, resulting scalable, versatile, and robust. The possibility to perform downstream mass spectrometry analysis is of particular importance since it enables the use of "omics" techniques for protein discovery and characterization. Our approach could be used as a starting point for the isolation of membrane proteins for pharmacological and biochemical studies, or for the discovery of new druggable or prognostic markers.

Optimization of Biomimetic, Leukocyte-Mimicking Nanovesicles for Drug Delivery Against Colorectal Cancer Using a Design of Experiment Approach.

The development of biomimetic nanoparticles (NPs) has revolutionized the concept of nanomedicine by offering a completely new set of biocompatible materials to formulate innovative drug delivery systems capable of imitating the behavior of cells. Specifically, the use of leukocyte-derived membrane proteins to functionalize nanovesicles (leukosomes) can enable their long circulation and target the inflamed endothelium present in many inflammatory pathologies and tumors, making them a promising and versatile drug delivery system. However, these studies did not elucidate the critical experimental parameters involved in leukosomes formulation. In the present study, we approached the preparation of leukosomes using a design of experiment (DoE) method to better understand the influence of experimental parameters on leukosomes features such as size, size distribution, and protein loading. We also validated this formulation technologically and tested its behavior in in vitro colorectal cancer (CRC) models, including CRC patient-derived tumor organoids (PDOs). We demonstrated leukosomes biocompatibility, endothelium adhesion capability, and tumor target in three-dimensional (3D) settings using CRC cell lines. Overall, our study offers a novel conceptual framework for biomimetic NPs using a DoE strategy and consolidates the high therapeutic potential of leukosomes as a viable drug delivery system for anti-inflammatory and antineoplastic applications.

LDL-Based Lipid Nanoparticle Derived for Blood Plasma Accumulates Preferentially in Atherosclerotic Plaque.

Apolipoprotein-based drug delivery is a promising approach to develop safe nanoparticles capable of targeted drug delivery for various diseases. In this work, we have synthesized a lipid-based nanoparticle (NPs) that we have called "Aposomes" presenting native apolipoprotein B-100 (apoB-100), the primary protein present in Low-Density Lipoproteins (LDL) on its surface. The aposomes were synthesized from LDL isolated from blood plasma using a microfluidic approach. The synthesized aposomes had a diameter of 91 ± 4 nm and a neutral surface charge of 0.7 mV ± mV. Protein analysis using western blot and flow cytometry confirmed the presence of apoB-100 on the nanoparticle's surface. Furthermore, Aposomes retained liposomes' drug loading capabilities, demonstrating a prolonged release curve with ∼80% cargo release at 4 hours. Considering the natural tropism of LDL towards the atherosclerotic plaques, we evaluated the biological properties of aposomes in a mouse model of advanced atherosclerosis. We observed a ∼20-fold increase in targeting of plaques when comparing aposomes to control liposomes. Additionally, aposomes presented a favorable biocompatibility profile that showed no deviation from typical values in liver toxicity markers (i.e., LDH, ALT, AST, Cholesterol). The results of this study demonstrate the possibilities of using apolipoprotein-based approaches to create nanoparticles with active targeting capabilities and could be the basis for future cardiovascular therapies.

Hemodialysis arteriovenous fistula ligation after renal transplantation: Impact on graft resistive index.

BACKGROUND: Kidney allograft resistive index (RI) is prognostic for graft and recipient survivals. Recipient hemodynamics could influence RI. In particular, dialysis arteriovenous fistula (AVF) has been involved in heart function changes, reversible after AVF ligation. Knowledge about AVF and RI is lacking. In this study, we prospectively evaluated RI changes after AVF ligation in kidney transplanted patients. METHODS: We enrolled 22 stable transplanted patients. Mean RI was measured before AVF ligation (T0), 18 to 24 h (T1) and 6 months (T6) after surgery; mean blood pressure (mBP), heart rate (HR), serum creatinine (sCr), estimated glomerular filtration rate (eGFR), 24 h proteinuria (24 h-P), immunosuppressive drug blood levels (IS) and antihypertensive drugs were also recorded. RESULTS: AVF ligation was performed 3.1 years (IQR: 2.1-3.8) after transplantation. Median AVF flow (Qa) was 1868 mL/min (IQR: 1538-2712) and 8 AVF were classified as high flow (Qa ≥ 2 L/min). At baseline, median sCr was 1.32 mg/dL (IQR: 1.04-1.76) and median eGFR was 57.1 mL/min. Median RI was 0.71 at T0, 0.69 at T1, 0.66 at T6. RI reduction at T1 and T6 was statistically significant (p < 0.05 and p < 0.001 respectively); in particular, 90.4% of patients had persistently improved values at T6. Furthermore, mBP increased while HR decreased. These changes were independent from sCr, 24 h-P, IS, antihypertensive drugs number, Qa and AVF type. CONCLUSIONS: AVF ligation improves kidney allograft RI; it may reflect better kidney perfusion.

Biomimetic Nanoparticles Potentiate the Anti-Inflammatory Properties of Dexamethasone and Reduce the Cytokine Storm Syndrome: An Additional Weapon against COVID-19?

Recent studies on coronavirus infectious disease 2019 (COVID-19) pathophysiology indicated the cytokine release syndrome induced by the virus as the main cause of mortality. Patients with severe COVID-19 infection present a systemic hyper inflammation that can lead to lung and multi-organ injuries. Among the most recent treatments, corticosteroids have been identified to be effective in mitigating these catastrophic effects. Our group has recently developed leukocyte-derived nanovesicles, termed leukosomes, able to target in vivo the inflamed vasculature associated with pathological conditions including cancer, cardiovascular diseases, and sepsis. Herein, to gain insights on the anti-inflammatory properties of leukosomes, we investigated their ability to reduce uncontrolled inflammation in a lethal model of lipopolysaccharide (LPS)-induced endotoxemia, recapitulating the cytokine storm syndrome observed in COVID-19 infection after encapsulating dexamethasone. Treated animals showed a significant survival advantage and an improved immune response resolution, as demonstrated by a cytokine array analysis of pro- and anti-inflammatory cytokines, chemokines, and other immune-relevant markers. Our results showed that leukosomes enhance the therapeutic activity of dexamethasone and better control the inflammatory response compared to the free drug. Such an approach could be useful for the development of personalized therapies in the treatment of hyperinflammation related to infectious diseases, including the ones caused by COVID-19.

Biomimetic cellular vectors for enhancing drug delivery to the lungs.

Despite recent advances in drug delivery, the targeted treatment of unhealthy cells or tissues continues to remain a priority. In cancer (much like other pathologies), delivery vectors are designed to exploit physical and biological features of unhealthy tissues that are not always homogenous across the disease. In some cases, shifting the target from unhealthy tissues to the whole organ can represent an advantage. Specifically, the natural organ-specific retention of nanotherapeutics following intravenous administration as seen in the lung, liver, and spleen can be strategically exploited to enhance drug delivery. Herein, we outline the development of a cell-based delivery system using macrophages as a delivery vehicle. When loaded with a chemotherapeutic payload (i.e., doxorubicin), these cellular vectors (CELVEC) were shown to provide continued release within the lung. This study provides proof-of-concept evidence of an alternative class of biomimetic delivery vectors that capitalize on cell size to provide therapeutic advantages for pulmonary treatments.

Reproducible and Characterized Method for Ponatinib Encapsulation into Biomimetic Lipid Nanoparticles as a Platform for Multi-Tyrosine Kinase-Targeted Therapy.

Ponatinib (Pon) is a multi-tyrosine kinase inhibitor that demonstrated high efficiency for treating cancer. However, severe side effects caused by Pon off-targeting effects prevent its extensive use. Using our understanding into the mechanisms by which Pon is transported by bovine serum albumin in the blood, we have successfully encapsulated Pon into a biomimetic nanoparticle (NP). This lipid NP (i.e., "leukosomes") incorporates membrane proteins purified from activated leukocytes that enable immune evasion, and enhanced targeting of inflamed endothelium NPs have been characterized for their size, charge, and encapsulation efficiency. Membrane proteins enriched on the NP surface enabled modulation of Pon release. These NP formulations showed promising dose-response results on two different murine osteosarcoma cell lines, F420 and RF379. Our results indicate that our fabrication method is reproducible, nonuser-dependent, efficient in loading Pon, and applicable toward repurposing numerous therapeutic agents previously shelved due to toxicity profiles.

Non-invasive assessment of the arrhythmogenic substrate in Brugada syndrome using signal-averaged electrocardiogram: clinical implications from a prospective clinical trial.

AIMS: Brugada syndrome (BrS) represents a major cause of sudden cardiac death in young individuals. The risk stratification to forecast future life-threatening events is still controversial. Non-invasive assessment of late potentials (LPs) has been proposed as a risk stratification tool. However, their nature in BrS is still undetermined. The purpose of this study is to assess the electrophysiological determinants of non-invasive LPs. METHODS AND RESULTS: Two hundred and fifty consecutive patients with (Group 1, n = 96) and without (Group 2, n = 154) BrS-related symptoms were prospectively enrolled in the registry. Signal-averaged electrocardiogram (SAECG) was performed in all subjects before undergoing epicardial mapping. Group 1 patients exhibited larger arrhythmogenic substrates (AS; 5.8 ± 2.8 vs. 2.6 ± 2.1 cm2, P < 0.001) with more delayed potentials (220.4 ± 46.0 vs. 186.7 ± 42.3 ms, P < 0.001). Late potentials were present in 82/96 (85.4%) Group 1 and in 31/154 (20.1%) Group 2 individuals (P < 0.001). Patients exhibiting LPs had more frequently a spontaneous Type 1 pattern (30.1% vs. 10.9%, P < 0.001), SCN5A mutation (34.5% vs. 21.2%, P = 0.02), and exhibited a larger AS with longer potentials (5.8 ± 2.7 vs. 2.2 ± 1.7 cm2; 231.2 ± 37.3 vs. 213.8 ± 39.0 ms; P < 0.001, respectively). Arrhythmogenic substrate dimension was the strongest predictor of the presence of LPs (odds ratio 1.9; P < 0.001). An AS area of at least 3.5 cm2 identified patients with LPs (area under the curve 0.88, 95% confidence interval 0.843-0.931; P < 0.001) with a sensitivity of 86%, specificity 88%, positive predictive value 85%, and negative predictive value 89%. CONCLUSION: The results of this study support the role of the epicardial AS as an electrophysiological determinant of non-invasive LPs, which may serve as a tool in the non-invasive assessment of the BrS substrate, as SAECG-LPs could be considered an expression of the abnormal epicardial electrical activity.ClinicalTrials.gov number (NCT02641431; NCT03106701).

Comparable clinical characteristics in Brugada syndrome patients harboring SCN5A or novel SCN10A variants.

AIMS: The Brugada syndrome (BrS) is an inherited disease associated with an increased risk of sudden cardiac death. Often, the genetic cause remains undetected. Perhaps due at least in part because the NaV1.8 protein is expressed more in both the central and peripheral nervous systems than in the heart, the SCN10A gene is not included in diagnostic arrhythmia/sudden death panels in the vast majority of cardiogenetics centres. METHODS AND RESULTS: Clinical characteristics were assessed in patients harboring either SCN5A or novel SCN10A variants. Genetic testing was performed using Next Generation Sequencing on genomic DNA. Clinical characteristics, including the arrhythmogenic substrate, in BrS patients harboring novel SCN10A variants and SCN5A variants are comparable. Clinical characteristics, including gender, age, personal history of cardiac arrest/syncope, spontaneous BrS electrocardiogram pattern, family history of sudden death, and arrhythmic substrate are not significantly different between probands harboring SCN10A or SCN5A variants. CONCLUSION: Future studies are warranted to further characterize the role of these specific SCN10A variants.

Macrophage-derived nanovesicles exert intrinsic anti-inflammatory properties and prolong survival in sepsis through a direct interaction with macrophages.

Despite numerous advances in medical treatment, sepsis remains one of the leading causes of death worldwide. Sepsis is characterized by the involvement of all organs and tissues as a consequence of blood poisoning, resulting in organ failure and eventually death. Effective treatment remains an unmet need and novel approaches are urgently needed. The growing evidence of clinical and biological heterogeneity of sepsis suggests precision medicine as a possible key for achieving therapeutic breakthroughs. In this scenario, biomimetic nanomedicine represents a promising avenue for the treatment of inflammatory diseases, including sepsis. We investigated the role of macrophage-derived biomimetic nanoparticles, namely leukosomes, in a lipopolysaccharide-induced murine model of sepsis. We observed that treatment with leukosomes was associated with significantly prolonged survival. In vitro studies elucidated the potential mechanism of action of these biomimetic vesicles. The direct treatment of endothelial cells (ECs) with leukosomes did not alter the gene expression profile of EC-associated cell adhesion molecules. In contrast, the interaction of leukosomes with macrophages induced a decrease of pro-inflammatory genes (IL-6, IL-1b, and TNF-α), an increase of anti-inflammatory ones (IL-10 and TGF-ß), and indirectly an anti-inflammatory response on ECs. Taken together, these results showed the ability of leukosomes to regulate the inflammatory response in target cells, acting as a bioactive nanotherapeutic.

p65BTK is a novel potential actionable target in KRAS-mutated/EGFR-wild type lung adenocarcinoma.

BACKGROUND: Lung cancer is still the main cause of cancer death worldwide despite the availability of targeted therapies and immune-checkpoint inhibitors combined with chemotherapy. Cancer cell heterogeneity and primary or acquired resistance mechanisms cause the elusive behaviour of this cancer and new biomarkers and active drugs are urgently needed to overcome these limitations. p65BTK, a novel isoform of the Bruton Tyrosine Kinase may represent a new actionable target in non-small cell lung cancer (NSCLC). METHODS: p65BTK expression was evaluated by immunohistochemistry in 382 NSCLC patients with complete clinico-pathological records including smoking habit, ALK and EGFR status, and in metastatic lymph nodes of 30 NSCLC patients. NSCLC cell lines mutated for p53 and/or a component of the RAS/MAPK pathway and primary lung cancer-derived cells from Kras/Trp53 null mice were used as a preclinical model. The effects of p65BTK inhibition by BTK Tyrosine Kinase Inhibitors (TKIs) (Ibrutinib, AVL-292, RN486) and first-generation EGFR-TKIs (Gefitinib, Erlotinib) on cell viability were evaluated by MTT. The effects of BTK-TKIs on cell growth and clonogenicity were assessed by crystal violet and colony assays, respectively. Cell toxicity assays were performed to study the effect of the combination of non-toxic concentrations of BTK-TKIs with EGFR-TKIs and standard-of-care (SOC) chemotherapy (Cisplatin, Gemcitabine, Pemetrexed). RESULTS: p65BTK was significantly over-expressed in EGFR-wild type (wt) adenocarcinomas (AdC) from non-smoker patients and its expression was also preserved at the metastatic site. p65BTK was also over-expressed in cell lines mutated for KRAS or for a component of the RAS/MAPK pathway and in tumors from Kras/Trp53 null mice. BTK-TKIs were more effective than EGFR-TKIs in decreasing cancer cell viability and significantly impaired cell proliferation and clonogenicity. Moreover, non-toxic doses of BTK-TKIs re-sensitized drug-resistant NSCLC cell lines to both target- and SOC therapy, independently from EGFR/KRAS status. CONCLUSIONS: p65BTK results as an emerging actionable target in non-smoking EGFR-wt AdC, also at advanced stages of disease. Notably, these patients are not eligible for EGFR-TKIs-based therapy due to a lack of EGFR mutation. The combination of BTK-TKIs with EGFR-TKIs is cytotoxic for EGFR-wt/KRAS-mutant/p53-null tumors and BTK-TKIs re-sensitizes drug-resistant NSCLC to SOC chemotherapy. Therefore, our data suggest that adding BTK-TKIs to SOC chemotherapy and EGFR-targeted therapy may open new avenues for clinical trials in currently untreatable NSCLC.

Novel SCN5A Frameshift Mutation in Brugada Syndrome Associated With Complex Arrhythmic Phenotype.

In this case report, we characterize a novel inherited frameshift mutation c.4700_4701del (p.Phe1567Cysfs*221) in a single copy of the SCN5A gene and its association with Brugada syndrome (BrS). The proband experienced a life-threatening ventricular arrhythmia successfully treated with DC-shock and he also suffered from supraventricular tachycardia. Ajmaline test confirmed the BrS diagnosis. No other mutation nor low frequency variants in the other 23 analyzed genes were detected. The same mutation was found in the father and sister, who were both diagnosed with BrS. We hypothesize that this mutation could be responsible for BrS and potentially linked to supraventricular tachycardias. Further studies are needed to confirm this observation and to assess the clinical relevance of this mutation, in terms of risk-stratification.