Folates dysmetabolism promotes atrial cardiomyopathy/fibrillation through a cardiac-bone marrow networking involving endothelial progenitor cell dysfunction and erythropoiesis diversion

Funding Acknowledgements

Type of funding sources: Private hospital(s). Main funding source(s): dedicated cardiovascular research foud

Background

Recent advances support the concept that pre-persistent Atrial Fibrillation (AF) does not explain the wholeness of embolic strokes, suggesting the recently postulated hypothesis of a broad Atrial Cardiomyopathy (AC). In contrast to its worldwide distribution and its very inclusive definition, pathogenic mechanisms underlying AC are still largely unknown. Folate cycle disorders (FCD) are a yet underrated dysmetabolism only partly explained by methylene tetrahydrofolate reductase (MTHFR)-inherited defects. On a translational basis, FCD could hinder both endothelial and circulating endothelial progenitor cell (EPCs) functioning, therefore providing one-shot explanation to both atrial stasis (increasing atrial fibrosis and generating atrial hypocontractility) and endothelial dysfunction (ED). If such cardiac-bone marrow networking would be verified, a fundamental pathogenic mechanism of AC and subsequent AF would be unraveled.

Purpose

This study aims to enquire for the hypothesis that: 1) atrial fibrosis (AFib) would relate to FCD (intended as both: a)MTHFR C677T inherited mutations and b)bone-marrow function disorders, here referring to erythropoiesis diversions) and 2) AF patients would show dysfunctional EPCs.

Methods

We studied 59 consecutive patients admitted to the Cardiology Unit of the General Hospital "F.Miulli", with preserved EF, subjected to AF ablation. AFib was quantified by relative % of low-voltage (<0,5 mV) bipolar peak-to-peak points, with respect to the wholeness of the endocavitary mapping. Blood count cell was evaluated. MTHFR C677T genotypes were elucidated by RT-PCR. Folate were measured by a commercial laboratory test. EPCs isolation and characterization were performed by Ficoll-Hypaque gradient and flow cytometry analysis for cell surface antigens: CD45, CD34, CD133, VEGFR2 and KDR. EPCs functional wound healing assay was performed.

Results

Baseline characteristics did not differ between Sample and Control groups (Fig. 1 – Left Table). % of Afib significantly differs between C677T MTHFR homozigosis patients (n=15) with respect to non-C677T MTHFR homozygosis patients (n=44) (Fig.1 – Right graph. - p < 0,02). Once univariate analysis was performed, subsequent multivariate analysis highlights highest fit once merged RBC, RDW-SD and folates values were inputed: Goodness of fit was proper, modelling good (Fig.2 – superior graph. - R2=0,39; p=0,0001). Either RBC, RDW-SD and folates coefficient reached significance (p < 0,0001; p < 0,01; p < 0,05 respectively). Number of EPCs significantly differs between AF patients and matched controls (Fig 2 – inferior graph. – p < 0,001).

Conclusions

Our findings support the hypothesis that genetically determined folates dysmetabolism (MTHFR dysfunction) promotes AFib via a complex cardiac-bone marrow networking involving circulating EPCs and unraveled by erythropoiesis diversions. Such results suggest a pathogenic role of folate cycle disorders in the AC development.

P365 CARDIOVASCULAR RISK SCORE MAY BE USEFUL IN STRATIFY DEATH RISK IN HOSPITALIZED COVID19 PATIENTS

Background

COVID–19 induce a robust systemic inflammation. Patients with cardiovascular disease (CVD) present an increased death risk. However, many efforts are spent to identify possible predictors of negative outcomes in order to have a more specific clinical setting. CVD score are useful tools in evaluation of risk of cardiovascular events Aim: We evaluated oxygenation and characteristics in COVID–19 according to cardiovascular risk stratification performed using Framingham (FRS) and Atherosclerotic cardiovascular disease (ASCVD) risk scores.

Material and Methods

We evaluated 155 COVID–19 patients (110 males and 45 females, aged 67.43±14.72 yrs). All patients underwent to a complete physical examination, chest imaging, laboratory tests, and blood gas analysis at the time of diagnosis. Seventeen patients died (10 males and 7 females, aged 74.71±7.23 yrs) while the remaining 138 patients (100 males and 38 females, aged 66.07±15.16 yrs) were alive at discharge.

Results

No differences there were in Hb, C–reactive protein nor in d–dimers between the two groups. Compared to alive, died group presents a significant increase in white blood cells (p < 0.05) and d–dimers (p < 0.05). No difference there were in pCO2, SO2, and in alveolar arteriolar oxygen difference (A–aDO2). On the contrary, in died patients there is an increased pO2 (p < 0.05) and a decreased ratio between oxygen inspired and pO2 (P/F; p < 0.05). Died patients have increased both in FRS (27.37±5.03 vs 21.33±9.49, p < 0.05) and ASCVD (40.18±20.36 vs 21.47±17.23, p < 0.05). FRS, but not ASCVD, presents a negative correlation to P/F (r–0.42, p < 0.05) in died while no correlation was found in alive. No other correlation has been found with blood gas parameters or in the phlogosis parameters evaluated in the two groups. ROC curve analysis showed a good performance in prediction of death for both scores (AUC FRS 0.71, ASCVD 0.77) with a good sensitivity (FRS 76.92%, ASVCD 75.00%) and specificity (FRS 65.00%, ASCVD 81.13%).

Discussion

CVD may be considered as a major risk factor for death in COVID–19 patients. The increase risk relates to a reduced lung capacity but it is not related to alteration in gas exchange. Similarly, CV risk results independent from inflammatory state we found. CVD risk score may be useful to stratify patients at admittance for a better treatment

P87 MEDIASTINAL SYNDROME REVEALED HEART LOCALIZATION OF A PRIMARY MEDIASTINAL B–CELL LYMPHOMA

Background

Primary mediastinal B–cell lymphoma (PMBCL) is an aggressive B–cell lymphoma that represents 2–3% of non –Hodgkin lymphoma cases and typically affects young adult Caucasian women. Diagnosis can be difficult and often need a multidisciplinary approach.

Case

a 75 year old female, with history of hypertension, came to ER for severe dyspnea. She complains also neck and left arm oedema. Blue swelling of face and trunk were described. Heart PoCUS was inconclusive, describing only a hypoechoic dilation of right atrium while the other three heart chambers were reduced in dimensions. Chest TC revealed a huge mediastinal mass next to a thrombosis of superior cava vein and right atrium (7 cm diameter) and a diffuse subsegmental pulmonary embolism. Arm and neck Lymphnodes were also enlarged . Low molecular weight heparin was given twice a day. Due the respiratory failure a high–flow nasal cannula oxygen treatment was performed. PET revealed FDG uptake in antero–superior mediastinum, but there was the same uptake in heart right atrium without a connection with the previous described. Therefore, this was no more considered as thrombus but as mass. The micro–bubble test revealed right to left shunt. She refused heart MRI. The patient was not suitable for an open–surgery biopsy, thus she was scheduled for a TC guided one, in order to obtain a pathological diagnosis for a suspected right atrium sarcoma. Due to the high risk we choose to perform the less invasive as possible way to have a histological sample. Thus, and intravascular biopsy of atrial mass by femoral vein was performed. The patient did not present any sequelae after procedure and she continued anticoagulation. The subsequent histological analysis revealed a PMBCL with a primary localization in Right atrium. Unfortunately, a sepsis by multiple resistant pseudomonas Aeruginosa and Aspergillus spp. arose and the patient died three weeks after biopsy.

Conclusion

A PMBCL is a rare and aggressive disease. Like in our patient, mediastinal syndrome is often associated to the disease. However, intracardiac localization are even rarer events. In large case series, less than 1% of intracardiac masses were lymphomas. In our patient, open–surgery was not suitable for multiple comorbidities. However, intravascular approach was less aggressive but effective to obtain enough tissue for diagnosis. Unfortunately, the immune suppression related to PMBCL and opportunistic infections drive a mortal sepsis.

P318 RIGHT HEART CHANGE IMPACTS ON SURVIVAL IN PATIENTS AFFECTED BY CARDIAC AMYLOIDOSIS: A SINGLE CENTRE STUDY

Amyloidosis is due to deposition of an excessive amount of protein in tissues. Cardiac Amyloidosis (CA) is an inauspicious prognostic factor and leading sudden death. We retrospectively analyzed 135 systemic amyloidosis, admitted between 1981 and 2019. 54 patients (46.30% F, aged 63.95±12.82) presented CA at baseline. In 53 patients, it was associated with a multiorgan involvement, while in one there was a primary myocardial deposition. We compared this group with the 81 patients (49.30% F, aged 58.33±15.65) who did not meet criteria for CA. CA presented a decreased SBP (p = 0.036), while nCA had an increased proteinuria (p = 0.02). TnI and NT–proBNP were significantly increased compared to nCA (p = 0.031 and p = 0.047, respectively). In CA patients we found an increased LDH compared to nCA (p = 0.0011). CA patients were also found to have an increased interventricular septum thickness compared to nCA (p = 0.002), a decreased Ejection Fraction (p = 0.0018) and Doppler velocity E/e’ ratio (p = 0.0095). Moreover, CA patients had an enhanced right atrium area (p = 0.0179), right ventricle basal diameter (p = 0.0112) and wall thickness (p = 0.0471) compared to nCA, and an increased inferior cava vein diameter (p = 0.0495) as well. TAPSE was the method chosen to evaluate systolic function of the right heart. In CA subjects very poor TAPSE levels were found compared to nCA patients (p = 0.0495). Additionally, we found a significant positive correlation between TAPSE and lymphocyte count (r = 0.47; p = 0.031) as well as Gamma globulins (r = 0.43, p = 0.033), Monoclonal components (r = 0.72; p = 0.047) and IgG values (r = 0.62, p = 0.018). CA patients had very poor survival rates compared to controls (30 vs. 66 months, p = 0.15). Mean survival of CA individuals was worse also when stratified according to NT–proBNP levels, using 2500 pg/mL as class boundary (174 vs. 5.5 months, respectively p = 0.013). In much the same way, a decreased right heart systolic function was correlated with a worse prognosis (18.0 months median survival, not reached in subjects with higher values than 18 mm, p = 0.0186). Finally, our data highlight the potential prognostic and predictive value of right heart alterations characterizing amyloidosis, as a novel clinical parameter correlated to increased LDH and immunoglobulins levels. Overall, we confirm the clinical relevance of cardiac involvement suggests that right heart evaluation may be considered as a new marker for clinical risk stratification in patients with amyloidosis.

P317 FATAL EVOLUTION IN A YOUNG WOMAN DUE TO AMYLOIDOSIS HEART FAILURE IN A RARE MULTIPLE MYELOMA DISEASE

Introduction

Immunoglobulin (Ig) D (IgD) monoclonal gammopathy is a rare subtype of multiple myeloma (MM) associated with a worse prognosis. Ig light chains amyloidosis is a disorder characterized by extracellular deposition of Ig light chains in various tissues, leading to organ dysfunction.

Case

A 29–year–old woman was admitted for dyspnea and tachycardia for moderate efforts. Lab revealed hypogammaglobulinemia with a monoclonal IgD K paraprotein. There was an increase in K free chains, with a dramatic increase in K/λ free chains Ratio. Proteinuria was 1360 mg/24h with a free K chains Bence Jones Protein. An increase in values of Troponin–I (137,5 pg/mL) and NT–proBNP (12527 pg/mL) pointed towards heart involvement. Furthermore, the ECG showed low voltages in the peripheral leads. Echocardiogram showed a moderate concentric left ventricular hypertrophy with diffused myocardial speckled pattern, an ejection fraction (EF) of 53% and PAPs of 71 mmHg and pericardial effusion. Chest CT scan showed bilateral pleural effusion. Spine MRI and whole body PET/CT indicated areas of osteolytic lesions. Plasma cells infiltration (85% CD138, MUM1 and K chains positivity) was present at bone marrow biopsy. Amyloid deposition was detected in abdominal fat tissue sample. Total bone scintigraphy excluded a transthyretin heart deposition. Thus, amyloidosis associate to IgD MM was diagnosed. In few days heart failure worsened (hs–cTnI 156,6 pg/mL; NT–proBNP 26583 pg/mL, EF 48%,) and the patient began complaining non–productive cough, dyspnea, and columnar edema of the lower limbs. She was not eligible for bone marrow transplantation, so daratumumab, bortezomib, melphalan and prednisone were administered. Despite serological improvement after a short five days course of therapy, she worsened with a further reduction of EF (35%). Blood gas analysis showed hypoxemia and lactate increase quickly turned into a cardiogenic shock. She died by cardiac arrest, just three weeks after admission.

Discussion

The present case is remarkable for age and gender of the patient as well as the rapid onset and fast worsening of symptoms, which were related to secondary heart amyloid deposition. Symptoms associated to cardiac amyloidosis are expressions of right heart involvement. The early good results of the therapy did not turn the evolution of disease. The fatal and overwhelming progression of the myocardial involvement led to the patient’s death in less than one month.

Bamlanivimab and Etesevimab administered in an outpatient setting for SARS-CoV-2 infection

The early administration of anti-SARS-CoV-2 monoclonal antibodies (mAb) could decrease the risk of severe disease and the need of inpatients care. Herein, our clinical experience with Bamlanivimab/Etesevimab for the treatment of early SARS-CoV-2 infection through an outpatient service was described. Patients with confirmed COVID-19 were selected by General Practitioners (GPs) if eligible to mAb administration, according to manufacturer and AIFA (Agenzia-Italiana-del-Farmaco) criteria. If suitability was confirmed by the Multidisciplinary Team, the patient was evaluated within the next 48-72 hours. Then, all patients underwent a medical evaluation, followed by mAb infusion or hospitalization if the medical condition had worsened. Overall, from March 29th to June 4th, 2021, 106 patients with confirmed COVID-19 were identified by GPs; 26 were considered not eligible and then excluded, while 9 refused treatment. Among the 71 remaining, 6 were not treated because of worsening of symptoms soon after selection. Finally, 65 received mAb therapy. All treated patients survived. However, 2/65 developed adverse events (allergic reaction and atrial fibrillation, respectively) and 6/65 needed hospitalization. By performing univariate logistic regression analysis, diabetes was the only risk factor for hospitalization after mAb administration [aOR = 9.34, 95%CI = 1.31-66.49, p= .026]. Importantly, subjects who worsened awaiting mAb were more frequently obese (OR = 16.66, 95%CI = 1.80-153.9, p= .013) and received home corticosteroid therapy for COVID-19 (OR = 14.11, 95%CI = 1.53-129.6, p= .019). Establishing a network among GPs and COVID units could be an effective strategy to provide mAb treatment to patients with early SARS-CoV-2 infection to reduce hospitalizations and pressure on healthcare systems.

Heme Oxygenase-1/High Mobility Group Box 1 Pathway May Have a Possible Role in COVID-19 ARDS (Acute Respiratory Distress Syndrome): A Pilot Histological Study

COVID-19 is a pandemic disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The persistent and excessive inflammatory response can build up a clinical picture that is difficult to manage and potentially fatal. Potent activators of inflammatory phenomena are damage-associated molecular patterns (DAMPs) and, in particular, the high-mobility group box 1 (HMGB1). HMGB1 is an intranuclear protein that is either passively released during hypoxia-related necrosis or actively released by macrophages. Heme oxygenase (HO-1) has an anti-inflammatory effect by inhibiting HMGB1, which could be a therapeutic target to reduce COVID-19 inflammation. In our study, we evaluated CD3, CD4, CD8, HMGB1 and HO-1 in the COVID-19 lung and correlated it to clinical data.

Analysis of Aortic Remodeling and Stiffness in Patients with Obstructive Sleep Apnea Syndrome: Preliminary Results

Obstructive sleep apnea (OSA) is a well-known risk factor for cardiovascular diseases. Several studies have shown that OSA is associated with vessel remodeling, but few studies have examined aorta.

AIM

to analyse aortic remodelling in OSA.

METHODS

Thirty consecutive OSA patients (22 males and 8 females, aged 58.5 ± 13.2 years) were studied. All patients underwent a morning blood gas analysis, a full cardiorespiratory evaluation, including nocturnal polygraphy and echocardiography, that assessed aortic root diameter (ARD) and aortic stiffness index (ASI). Patients were grouped as follows: Group 1, non-severe OSA (Apnea-Hypopnea Index; AHI <30, 14 patients); Group 2, severe OSA (AHI ≥30, 16 patients).

RESULTS

No difference was found between the groups in ARD as absolute value (Group 1, 33.64 ± 0.91 mm; Group 2, 33.64 ± 1.02, p = ns) and as normalized value for the body surface area - ARDi (Group 1, 16.72 ± 0.63 mm/m²; Group 2, 16.09 ± 0.44, p = ns). Moreover, no difference was found in the ASI (Group 1, 14.04 ± 2.26; Group 2, 13.41 ± 2.22, p = ns). Considering all OSA patients, AHI showed an inverse correlation with ARDi (p = 0.018) and ASI (p = 0.0449). Moreover, the ASI showed a direct correlation with ARDi (p = 0.01) and morning PaO2 (p = 0.0349) as well as an inverse correlation with the oxygen desaturation index (ODI, p = 0.031) and total time with apnea and hypopnea (p = 0.039).

CONCLUSION

No difference was found between severe and non-severe OSA in ARD. Surprisingly, the data show that the severity of OSA correlates inversely with the ASI and ARDi. The relation between PaO2 and stiffness might be explained by a feedback mechanism that tries to overcome the reduction of aortic elasticity due to night desaturation. These findings need to be investigated in further studies with a larger study population.

Belimumab restores Treg/Th17 balance in patients with refractory systemic lupus erythematosus

Belimumab, a specific inhibitor of the soluble B lymphocyte stimulator (BlyS), is the first biological drug approved by the United States Food and Drug Administration for the treatment of patients with active systemic lupus erythematosus (SLE) refractory to standard therapy. Given that an imbalance between regulatory T cells (Treg) and interleukin (IL)-17A-secreting T cells (Th17) has been reported in various autoimmune disorders, we assessed the frequency of both Treg and Th17 peripheral blood populations before and after belimumab administration in 20 patients with active SLE refractory to standard therapy. After six months of treatment, the mean SELENA-SLEDAI score as well as the mean anti-double-stranded DNA antibody titers were significantly decreased. In addition, we observed a significant increase in Treg percentages and a parallel, significant decrease in Th17 percentages, accompanied by significantly reduced serum levels of IL-21. In vitro studies showed that Treg purified from belimumab-treated patients were fully functional and displayed a suppressor function similar to that of Treg purified from healthy donors. Belimumab can restore Treg/Th17 balance in SLE patients with uncontrolled disease activity, and this results in decreased flare rate and reduced glucocorticoid dosage.

[Hemorheology and microcirculation in some pathologies of internal medicine]

AIM

It is very interesting in physiopathology to evaluate the blood flow in the microvasculature of patients affected by diabetes, arterial hypertension, lipoproteinosis, peripheral occlusive arterial disease (POAD) and liver failure.

METHODS

We studied 4 groups. Group 1: controls formed by 25 healthy subjects (15 males and 10 females aged 36+/-3 years); group 2: diabetes, including 32 patients (group 2A, 20 subjects with diabetes type 1: 12 males and 8 females aged 43+/-4 years and group 2B, 12 subjects with diabetes type 2: 6 males and 6 females aged 45+/-3 years); group 3: liver failure, formed by 6 subjects (3 males and 3 females aged 44+/-5 years); group 4: hypertensives, 50 subjects (group 4A, 28 smokers 12 males and 16 females aged 40+/-4 years and group 4B, 22 non-smokers: 12 males and 10 females aged 38+/-3 years). We evaluated the capillary morphology using computerized videocapillaroscopy, the hemorheology (red blood cell RBC deformability and aggregability) using LORCA (Laser assisted Optical Rotational Red Cell Analyzer) and tissue oxygenation using transcutaneous oxymeter (Periflux 5000 Perimed). Statistical analysis were performed using the Student t-test.

RESULTS

The capillary loops in patients with diabetic microangiopathy had in 50% of the patients studied an image such as ''deer horns'', as ''elephant nose'' in 72% and as ''cork screw'' in 44%. In diabetics we found also a capillary rarefaction in 28% of them. An improvement in perfusion was observed in patients with liver failure one week after liver transplantation from cadaver in 83% of them. Morphological alterations were present in hypertensives (27% in non-smokers, 46% in smokers). The RBC deformability evaluated as elongation index (EI) and RBC aggregability (t1/2 expressed in seconds) were detected using LORCA. Group 1: EI 0.59+/-0.02, t1/2 3+/-1 s; group 2A: EI 0.55+/-0.01; t1/2 2+/-0.5 s p<0.05 vs controls; group 2B: EI 0.56+/-0.01; t1/2 2+/-0.2 s p<0.04 vs controls; group 3: EI 0.56+/-0.02, t1/2 2+/-0.4 s p<0.04; group 4A: EI 0.56+/-0.02, t1/2 2+/-0.6 s p<0.03; group 4B: 0.57+/-0.02, t1/2 2+/-0.6 s p<0.04. We evaluated also the TcpO2 at the dorsum of the right foot expressed in mmHg: group 1, 96+/-11 mmHg; group 2A, 74+/-9 p<0.05 vs controls; group 2B, 76+/-8 mmHg p<0.05; group 3, 69+/-6 mmHg p<0.05; group 4A, 70+/-5 mmHg p<0.05; group 4B, 77+/-9 mmHg p<0.05.

CONCLUSION

This study indicates an interesting and complete methodology in order to evaluate the microcirculation condition in different pathologies inducing microvasculature alterations.