Single cell atlas of cd45+ cells in angiotensin II-induced hypertension

 

Hypertension has been recently identified as an inflammatory disease. Immune cell infiltration is a characteristic feature in the vasculature and the kidneys in experimental hypertension, but the unique nature of such inflammatory infiltrates has not yet been comprehensively characterised.

Accordingly, we aimed to provide in-depth characteristics of immune cells in the vasculature and the kidneys in experimental hypertension.

To achieve this, we used single-cell RNA-sequencing of leukocytes (CD45+ cells were sorted) using the 10x Genomics platform in the aortas and the kidneys of male 12-week-old C57BL/6J mice (n=16–17/group) upon AngII (490 ng/min/kg) or sham buffer 14-day infusion, using osmotic minipumps. Samples were pooled to analyse three independent replicates. Bioinformatics analysis used Seurat/R to identify immune cell subpopulations and characterise differentially expressed genes (DEGs), pathways, and interactions signatures.

Ang II infusion increases the total number of CD45+ leukocytes in the aorta (346.7±89.1 vs. 1210±214.3; p=0,048), while in the kidneys, this was much less pronounced (1.1±0.5 fold vs. sham). Fifteen leukocyte populations/clusters were identified in the aorta and kidney based on their unique markers. In the aorta, shifts in numerous populations were evident, with the most significant differences in tissue-resident macrophages and activated tissue-resident macrophages, monocyte-derived dendritic cells and NK cells (Figure 1). Kidneys did not display such profound changes. The transcriptomic profile analysis showed 767 significant DEGs in the aorta and only 35 in the kidney. CellChat analysis also indicated more robust interactions between the immune cells in the aorta than in kidneys. These included Ifitm1, Apoe, Il1b, and C1q a/b/c, which were shared between aorta and kidney and may play an immunoregulatory role, affecting smooth muscle cell proliferation and arterial vascular remodelling. Top up-regulated leukocyte genes in the aorta included Ccl8, Ccl3, Cxcl2, Lyz2, and Spp1, while in the kidney, Cd74, Cst3, Fos, Fcer1g, Tyrobp, and Ccl4. GO pathway signatures of aortic leukocyte DEGs revealed pathways related to leukocyte migration, cytokine production, T cell activation, and leukocyte activation and adhesion. Cell-specific analysis showed that macrophage subpopulations most strongly increased in Ang II-induced hypertension displayed the most pronounced changes in the transcriptome profiles and cell-cell interactions.

Comprehensive single-cell RNA sequencing identifies tissue-resident macrophages, monocyte-derived dendritic cells, and NK cells as most affected leukocyte subpopulations in hypertensive vasculature. Differentially expressed genes support the role of these cells in vascular remodelling and propagation of inflammation, further supporting the identification of these cells as potential future targets for therapeutic interventions in hypertension.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Research Council

Local gentamicin-collagen sponge reduces cardiovascular implantable electronic device infections and pocket hematoma

OBJECTIVE

Implantation or replacement of a cardiovascular implantable electronic device (CIED) may be associated with complications, such as pocket hematomas and infections. This study aims to determine whether a lyophilized gentamycin-containing collagen implant (GCCI) reduces major CIED infections and pocket hematomas after implant.

SUBJECTS AND METHODS

A retrospective study was conducted among patients who underwent implantation or replacement of CIED at the Tor Vergata Polyclinic (Rome, Italy) between June 2007 and November 2019. The primary combined endpoint was infection and hematoma occurrence through 12 months of follow-up post-procedure. The rate of single infectious complications, pocket hematomas or both were also assessed.

RESULTS

We compared 475 patients treated with the GCCI (GCCI group) with 714 patients who did not receive it (control group). Complications occurred in 127 patients (11%); a statistically significant reduction of infections and pocket hematomas in the GCCI group was reported when compared with control patients (1% vs. 17%; p<0.0001). A total of 20 (2%) infectious events were reported, 102 (8%) patients developed a pocket hematoma, and 5 (0.4%) had both. The rate of single complications was significantly lower in GCCI group: infection 0.2% vs. 2.6% (p=0.002), pocket hematoma 0.6% vs. 13.8% (p<0.001). The association between antiplatelet/anticoagulation therapy and hematoma development was not statistically significant.

CONCLUSIONS

The GCCI is a medical device that can be used in addition to local hemostasis and prophylactic doses of systemic antibiotics with the aim of reducing infective complications and pocket hematoma after permanent CIED implantation or replacement.

SCN5A mutation is associated with severity of abnormalities detected by ECG imaging in Brugada syndrome

Funding Acknowledgements

Type of funding sources: None.

Background

Brugada syndrome (BrS) is caused by mutations in SCN5A gene in 15%-20% of cases. Previous studies showed a worse prognosis in SCN5A mutation carriers (SCN5A+).

Purpose

To evaluate genotype-phenotype correlation with ECG imaging (ECGI).

Methods

All consecutive patients who underwent ECGI with CardioInsight for BrS were retrospectively analyzed. ECGI parameters analyzed before and after ajmaline administration were: 1) Right ventricular outflow tract (RVOT) activation time (RVOT-AT) and 2) RVOT recovery time (RVOT-RT). Genetic analysis was performed in all patients with SeqCap EZ Human Exome Probes v3.0 for BrS. Patients were defined as SCN5A+ if they had a pathogenic/likely pathogenic mutation in SCN5A following ACMG guidelines.

Results

Thirty-six BrS patients were included and 8 patients (22%) were SCN5A+. At baseline ECGI map, mean RVOT-RT was higher in SCN5A+ [384.8 ms vs 362 ms, p=0.037], with no difference in RVOT-AT (p=0.65). After ajmaline administration SCN5A+ patients showed higher RVOT-AT [125.6 ms vs 102.4 ms, p=0.045] (Figure) and higher RVOT-RT [426.4 ms vs 400 ms, p=0.038]. At univariate logistic regression, baseline RVOT-RT was a predictor of SCN5A mutation (specificity: 0.64, sensitivity 0.88, AUC 0.75).

Conclusion

In BrS syndrome SCN5A+ patients exhibit marked depolarization and repolarization abnormalities as assessed by ECGI.

Left atrial function after standalone totally thoracoscopic left atrial appendage exclusion in af patients with absolute contraindication to oral anticoagulation therapy

Funding Acknowledgements

Type of funding sources: None.

Introduction

Left atrial appendage (LAA) is the source of more than 90% of thrombi in patients with atrial fibrillation (AF).  The Totally Thoracoscopic (TT) LAA exclusion with epicardial clip has become a safe and effective procedure, but the effect on left atrial (LA) function remains unknown.

Purpose

The aim of this study was to assess the effect of TT LAA exclusion on LA function.

Methods

20 patients (15 males) with non-valvular AF and contraindication to oral anticoagulation therapy (OAT) or antiplatelet therapy underwent standalone TT LAA exclusion with the Atriclip Pro II device. All patients were screened preoperatively with 3D CT scan, trans-esophageal echocardiography, spirometry and cerebrovascular doppler ultrasound. Intraoperative Atriclip Pro II positioning and LAA exclusion were guided and confirmed by trans-esophageal echo. To objectify LA function, transthoracic echocardiography with 2D Speckle tracking was performed before surgery, at discharge and at 3-month follow-up. All patients were not on anticoagulation nor antiplatelet therapy at the time of surgery, at discharge and at control visit.

Results

Baseline characteristics are reported in Table I. There were no major complications during the procedures. One non cardiovascular death, one minor stroke and 4 hospitalizations occur at 1-year follow up. The reservoir LA function considering the strain measurements dramatically decreased few days after the procedure and it recovered at 3-month follow-up compared to baseline, even though the LA volume is augmented (Table II). Furthermore, NT pro-BNP increased and ventricular strain decreased significantly after the procedure recovering over time.

Conclusion

TT LAA exclusion with Atriclip Pro II device is a safe and effective procedure in preventing AF related stroke in patients with contraindication to OAT. Our findings suggest that the LAA epicardial clip impairs immediately the reservoir LA function that recovers over time. Abstract Table I  Abstract Table II

New insights into risk stratification of Brugada syndrome from high density epicardial electroanatomic mapping

Background/Introduction

Brugada syndrome (BrS) has been initially described as a channelopathy with no structural heart disease but a growing body of evidence points towards structural anomalies in the epicardium of right ventricle outflow tract (RVOT-EPI). Since its first description the electrical substrate of BrS has been thought to be a fractionation of the electrograms (EGMs) in the RVOT-EPI. Also there is recent evidence that SCN5A mutation BrS patients might be at increased risk of sudden cardiac death (SCD). No studies correlated high-density mapping substrate with clinical outcomes.

Purpose

The aim of the current study was to compare clinical characteristics of BRS patients with EGMs characteristics from high-density epicardial mapping with Advisor HD-Grid mapping catheter.

Methods

All consecutive patients with BrS who underwent hybrid RVOT-EPI substrate ablation at our University Hospital between April 2018 and March 2021 were retrospectively included in the study. Genetic analysis was performed in all patients and clinical data were collected. BrS was diagnosed following current recommendations. Inclusion criteria were: 1) use of Advisor HD-Grid mapping catheter and 3D-electroanatomical (EAM) mapping system EnSite Precision; 2) acquisition of EAM before and after ajmaline infusion at standard protocol (1 mg/kg in 5 minutes). Bipolar EGMs were considered abnormal (aEGMs) if they met at least 1 of the following: prolonged duration (&gt;80 ms), fragmented components (at least 2 distinct peaks), and/or late potentials extending beyond the end of the QRS complex. aEGMs duration (Ed) was defined as the time from surface QRS onset in D2 to bipolar EGM offset.

Results

Fifteen patients were included in the study. Six patients (40%) had history of SCD or inducible ventricular arrhythmias (VAs) at electrophysiological study and 5 patients (33.3%) had a mutation of SCN5A. The mean number of points of EAMs was 1020±500. Patients with history of SCD or VAs compared with patients without history had similar Ed before ajmaline [117.5 ms (100.6–132.5) vs 110.5 ms (106.8–114.8), p=0.72] but longer Ed after ajmaline [247.5 ms (231.6–273.9) vs 188.0 ms (178.0, 211.5), p=0.034]. The best cutoff of Ed after ajmaline to predict VAs history was 233 msec (AUC of the model 0.83, sensitivity: 0.98, specificity: 0.66). Patients with SCN5A mutation compared with patients without had similar Ed before ajmaline [125.2 ms (117.9–132.6) vs 105.0 ms (103.0–119.0), p=0.24] but longer Ed after ajmaline [270.0 ms (259.0–280.5) vs 200.8 ms (181.2–224.2), p=0.037], figure 1. The best cutoff of Ed after ajmaline to predict SCN5A mutation was 256.5 ms (AUC of the model 0.84, sensitivity: 0.80, specificity: 0.98), figure 2.

Conclusions

High density RVOT epicardial mapping provides data of clinical meaning in risk stratification of BrS patients. These data should be interpreted in the context of a population undergone RVOT-EPI substrate ablation.

Funding Acknowledgement

Type of funding sources: None. aEGM duration and SCD/VA or SCN5AROC curves for EGM derived prediction

A local gentamicin-collagen sponge reduces cardiovascular implantable electronic device infections and pocket hematoma

Background

Implantation or replacement of cardiovascular implantable electronic device (CIED) may be associated with complications such as pocket hematoma and infections.

Purpose

The aim of this study is to determine whether a lyophilized collagen impact impregnated with the aminoglycoside antibiotic gentamicin, applied according to the size of pocket into the surgical wound during implantation or replacement, reduces major CIED infections and pocket hematoma 12 months after the surgical intervention.

Methods

We conducted a retrospective study including 1189 patients (mean age 77.45±9.83 y.o.), who underwent implantation or replacement of CIED in our center between June 2007 and November 2018. We compared 475 patients treated with the local gentamicin-collage sponge (group I) with 714 patients who did not receive it (group II). The primary endpoints were the reduction of infectious complications and pocket hematoma through 12 months of follow-up post procedure.

Results

Complications occurred in 127 of 1189 patients (10.68%): 102 of 1189 patients (8.58%) developed pocket hematoma, 20 of 1189 patients (1.68%) infectious events and 5 of 1189 patients (0.42%) both. Specifically, the rate of complications was lower in group I: pocket hematoma 0.63% vs 13.86% (p&lt;0.001), infections 0.21% vs 2.6% (p=0.02), both 0% vs 0.7% (p=0.17). The study also shows a statistically significant major incidence of infectious complications in subjects undergoing implantation or replacement of ICD, compared to subjects undergoing implantation or replacement of PPM (5.59% vs 1.5%; p&lt;0.05%).

Regarding the type of intervention and the incidence of complications within the subgroups, was demonstrated a statistically significant reduction in the incidence of infections in de novo implant-group I subgroup compared to de novo implant-group II subgroup (0.5% vs 3.5%; p&lt;0.05); a statistically significant reduction in the incidence of infectious complications was also observed in replacement-group I subgroup (0%) compared to replacement-group II subgroup (0% vs 1.4%; p&lt;0.05). Similar results were demonstrated for the incidence of pocket hematoma, with a statistically significant reduction in de novo implant-group I subgroup compared to de novo implant-group II subgroup (0.5% vs 14.13%; p&lt;0.05) and in replacement-group I subgroup compared to replacement-group II subgroup (1.4% vs 12.5%; p&lt;0.05).

The association between therapy and development of hematoma was not statistically significant. The association between comorbidities and infectious complications in both groups was always statistically significant.

Conclusion

The local gentamicin-collagen sponge is a medical device which can be used in addition to local hemostasis and prophylactic doses of systemic antibiotics, with the aim of reducing infective complications and pocket hematoma after permanent CIED implantation or replacement.

Funding Acknowledgement

Type of funding source: None

P1296 Effects of contact-to-balloon time on variations of the left ventricle global and regional function during hospitalization of STEMI patients: an echocardiographic study

Background

Ischemic time duration is one of the most important determinants of infarct size in patients with ST-segment elevation myocardial infarction (STEMI). An early reperfusion with percutaneous coronary intervention (PCI) therapy reduces the adverse events and mortality. It also influences the wall motion abnormalities and left ventricular ejection fraction (LVEF), which can be easily detected by a standard transthoracic echocardiogram (TTE).

Purpose

Aim of our study was to assess the immediate effects of an early percutaneous revascularization in STEMI patients on variations of the left ventricle (LV) global and regional function.

Methods

The study population consists of 141 consecutive patients with STEMI undergoing PCI from January to June 2018. The population was divided into two groups basing on first medical contact-to-balloon time (C2B), respectively ≤90 minutes and &gt;90 minutes. Cardiac biomarkers were obtained uniformly. A standard TTE was performed in all patients, at moment of in-hospital admission and at the time of discharge, recording the LV wall motion abnormalities and LVEF, using the wall motion score index (WMSI) and modified Simpson’s rule, respectively. Finally, we performed a sub-analysis in the group of patients who showed an improvement of the LVEF ≥10% at discharge.

Results

In both groups at baseline, patients suffered from a moderately reduced LVEF (41 ± 8.3% in ≤90 min group vs 40.97 ± 8.91% in &gt;90 min group, p = ns). A WMSI &gt;1 was recorded uniformly: 1.78 ± 0.39 in patients with C2B ≤90 min and 1.81 ± 0.40 in patients with C2B &gt;90 min, without significant differences between the two groups. At the time of discharge, a significant improvement of LVEF (from 41 ± 8% to 44 ± 9%, p = 0.013) and WMSI (from 1.78 ± 0.39 to 1.64 ± 0.38, p = 0.036) exclusively emerged in the ≤90 min group. Furthermore, we identified 37 patients who experienced, at the time of discharge, an improvement of the LVEF ≥10% compared to baseline values. In these patients the C2B time resulted significantly shorter, when compared with patients with LVEF improvement &lt;10%: 42 min (IQR 18.5-77.5) vs. 104 (IQR 48-176), p &lt; 0.0001. Additionally, these patients had lower significant levels of cardiac biomarkers. A significant improvement in WMSI was also observed in the ≥10% group (1,69 ± 0,41 vs 1,49 ± 0,41, p= 0.039).

Conclusion

Our study shows the immediate effects of an early revascularization. In particular, the duration of C2B time influences the recovery of ventricular function, in terms of ejection fraction and parietal kinetics. A standard TTE is a low cost and easily available examination, which may provide immediate results without impacting significantly on health costs.

Different Methods for Inlay Production: Effect on Internal and Marginal Adaptation, Adjustment Time, and Contact Point

The aim of this study was to evaluate the effect of different production methods of resin and ceramic inlays on marginal and internal adaptation, adjustment time, and proximal contacts. Forty premolars were selected, embedded (their roots), and prepared to receive inlays that were made as follows (n=10): LaRe-digital impression with a Lava C.O.S. scanner, followed by milling of Lava Ultimate block (composite resin) in a milling center; CeRe-digital impression with a Cerec 3D Bluecam scanner, followed by milling of Lava Ultimate block in Cerec; CeDis-digital impression with a Cerec 3D Bluecam scanner, followed by milling of IPS e.max CAD block (lithium disilicate) in Cerec; and PresDis-impression with polyvinyl siloxane, inlay made using the lost wax technique and IPS e.max Press pressed ceramic (lithium disilicate). Marginal and internal adaptations were measured using the replica technique. The inlay adjustments were performed using diamond burs in a contra-angle hand piece, and the time for adjustment was recorded using a timer, in seconds. The tightness of the proximal contact was measured using standardized metal blades. The statistical analyses for marginal fit data showed that at the cervical edge, CeDis (177.8 μm) had greater misfit than CeRe (116.7 μm), while all the groups had similar adaptation at the occlusal edge. The groups had similar internal fit at the pulpal wall, while LaRe (104.7 μm) > CeDis (66.7 μm) = CeRe (76.7 μm) at the axial wall. The groups restored with lithium disilicate ceramic took more time for adjustment when compared to the resin restorative material. The lowest proximal contact, in micrometers, was seen in the CeRe group (8.8 μm).

Cardiometabolic and immune factors associated with increased common carotid artery intima-media thickness and cardiovascular disease in patients with systemic lupus erythematosus

BACKGROUND AND AIM

Patients with systemic lupus erythematosus (SLE) have a higher prevalence of subclinical atherosclerosis and higher risk of cardiovascular (CV) events compared to the general population. The relative contribution of CV-, immune- and disease-related risk factors to accelerated atherogenesis in SLE is unclear.

METHODS AND RESULTS

Fifty SLE patients with long-lasting disease (mean age 44 ± 10 years, 86% female) and 50 sex- and age-matched control subjects were studied. Common carotid artery intima-media thickness (CCA-IMT) was used as a surrogate marker of atherosclerosis. We evaluated traditional and immune- and disease-related factors, assessed multiple T-cell subsets by 10-parameter-eight-colour polychromatic flow cytometry and addressed the effect of pharmacological therapies on CCA-IMT. In SLE patients, among several cardiometabolic risk factors, only high-density lipoprotein levels (HDL) and their adenosine triphosphate-binding cassette transporter 1 (ABCA-1)-dependent cholesterol efflux capacity were markedly reduced (p < 0.01), whereas the CCA-IMT was significantly increased (p = 0.03) compared to controls. CCA-IMT correlated with systolic blood pressure, low-density lipoprotein (LDL) cholesterol and body mass index (BMI), but not with disease activity and duration. The activated CD4(+)HLA-DR(+) and CCR5(+) T-cell subsets were expanded in SLE patients. Patients under hydroxychloroquine (HCQ) therapy showed lower CCA-IMT (0.62 ± 0.08 vs. 0.68 ± 0.10 mm; p = 0.03) and better risk-factor profile and presented reduced circulating pro-atherogenic effector memory T-cell subsets and a parallel increased percentage of naïve T-cell subsets.

CONCLUSION

HDL represents the main metabolic parameter altered in SLE patients. The increased CCA-IMT in SLE patients may represent the net result of a process in which 'classic' CV risk factors give a continuous contribution, together with immunological factors (CD4(+)HLA-DR(+) T cells) which, on the contrary, could contribute through flares of activity of various degrees over time. Patients under HCQ therapy present a modified metabolic profile, a reduced T-cell activation associated with decreased subclinical atherosclerosis.

Imaging of the vulnerable carotid plaque: biological targeting of inflammation in atherosclerosis using iron oxide particles and MRI

OBJECTIVES

Identification of those patients with high-risk asymptomatic carotid plaques remains an elusive but essential step in stroke prevention. Inflammation is a key process in plaque destabilization and the propensity of atherosclerotic lesions to cause clinical sequelae. There is currently no clinical imaging technique available to assess the degree of inflammation associated with plaques. This study aims at visualizing and characterizing atherosclerosis using antibody-conjugated superparamagnetic iron oxide (SPIO) particles as an MRI probe to assess inflammation in human atherosclerotic plaques.

METHODS

Atherosclerotic plaques were collected from 20 consecutive patients (n=10 from symptomatic patients, n=10 from asymptomatic patients) undergoing carotid endarterectomy (CEA) for extracranial high-grade internal carotid artery (ICA) stenosis (>70% luminal narrowing). Inflammatory markers on human atherosclerotic plaques were detected and characterized by ex vivo magnetic resonance imaging (MRI) using anti-VCAM-1 antibody and anti-E-selectin antibody-conjugated SPIO with confirmatory immunohistochemistry.

RESULTS

Inflammation associated with human ex vivo atherosclerotic plaques could be imaged using dual antibody-conjugated SPIO by MRI. Symptomatic plaques could be distinguished from asymptomatic ones by the degree of inflammation, and the MR contrast effect was significantly correlated with the degree of plaque inflammation (r=.64, p<.001). The asymptomatic plaque population exhibited heterogeneity in terms of inflammation. The dual-targeted SPIO-induced MR signal not only tracked closely with endothelial activation (i.e. endothelial expression of VCAM-1 and E-selectin), but also reflected the macrophage burden within plaque lesions, offering a potential imaging tool for quantitative MRI of inflammatory activity in atherosclerosis.

CONCLUSIONS

These functional molecular MRI probes constitute a novel imaging tool for ex vivo characterization of atherosclerosis at a molecular level. Further development and translation into the clinical arena will facilitate more accurate risk stratification in carotid artery disease in the future.