First experiences of ultrasound vector flow imaging at the femoropopliteal artery in peripheral arterial disease

Background: The femoropopliteal artery (FPA) plays a central role in diagnosing and treating peripheral arterial disease (PAD). FPA lesions are the most frequent cause of intermittent claudication, and no other artery of the lower extremities is recanalised more frequently. Generally, ultrasound is the primary imaging tool in PAD, particularly FPA. With the development of high-frame-rate ultrasound technology in addition to traditional ultrasound modes, vector flow imaging (VFI) has provided deeper haemodynamic insights when used in the carotid artery. Here, we report the use of VFI at the FPA level in routine PAD examinations. Patients and methods: In this single-centre prospective study, we evaluated consecutive patients with PAD using B-mode imaging, colour Doppler, pulsed wave Doppler (PW) and vector flow. Hemodynamic parameters at predefined locations at the carotid artery and FPA were compared. Results: Qualitatively adequate VFI at all sites was possible in 76% of the patients with PAD. With decreasing volume flow from the common carotid artery to the internal carotid artery and from the common femoral artery via the superficial femoral artery to the popliteal artery, the correlation between VFI- and PW-derived-volume flow was high at every site. Based on different techniques, the VFI-derived values were significantly lower than the PW-derived values. The mean wall shear stress was significantly lower at all femoropopliteal sites than at the carotid sites, whereas the oscillatory shear index at the femoral site was higher than that at the carotid sites rather than at the popliteal location. Conclusions: Our findings suggest that vector flow data acquisition in the FPA is feasible in most patients with PAD. Therefore, with knowledge of the method and its limitations, VFI provides haemodynamic information beyond traditional ultrasound techniques and is a promising new tool for flow analysis in PAD.

Prognostic value of extended cardiac risk assessment before elective open abdominal aortic surgery

BACKGROUND

Major vascular surgery is associated with a high perioperative risk and significant mortality. Despite advances in risk stratification, monitoring, and management of perioperative complications, cardiac complications are still common. Stress echocardiography is well established in coronary artery disease diagnostics; however, its prognostic value before high-risk aortic surgery is unknown. This prospective, single-center study compared the outcome of patients undergoing extended cardiac risk assessment before open abdominal aortic surgery with the outcome of patients who had received standard preoperative assessment.

METHODS

The study included patients undergoing elective open abdominal aortic surgery. Patients who underwent standard preoperative assessment before the start of a dedicated protocol were compared with patients who had extended cardiac risk assessment, including dobutamine stress echocardiography, as part of a stepwise interdisciplinary cardiovascular team approach. The combined primary endpoint was cardiovascular death, myocardial infarction, emergency coronary revascularization, and life-threatening arrhythmia within 30 days. The secondary endpoint was acute renal failure and severe bleeding.

RESULTS

In total, 77 patients (mean age 68.1 ± 8.1 years, 70% male) were included: 39 underwent standard and 38 underwent cardiac risk assessment. The combined primary endpoint was reached significantly more often in patients before than after implementation of the extended cardiac stratification procedure (15% vs. 0%, p = 0.025). The combined secondary endpoint did not differ between the groups.

CONCLUSIONS

Patients with extended cardiac risk assessment undergoing elective open abdominal aortic surgery had better 30-day outcomes than did those who had standard preoperative assessment.

Improved mid-term stability of MR reduction with an increased number of clips after percutaneous mitral valve repair in functional MR

Background

Percutaneous mitral valve repair (PMVR) has evolved to be a standard procedure in suitable patients with mitral regurgitation (MR) not accessible for open surgery. Here, we analyzed the influence of the number and positioning of the clips implanted during the procedure on MR reduction analyzing also sub-collectives of functional and degenerative MR (DMR).

Results

We included 410 patients with severe MR undergoing PMVR using the MitraClip® System. MR and reduction of MR were analyzed by TEE at the beginning and at the end of the PMVR procedure. To specify the clip localization, we sub-divided segment 2 into 3 sub-segments using the segmental classification of the mitral valve.

Results

We found an enhanced reduction of MR predominantly in DMR patients who received more than one clip. Implantation of only one clip led to a higher MR reduction in patients with functional MR (FMR) in comparison to patients with DMR. No significant differences concerning pressure gradients could be observed in degenerative MR patients regardless of the number of clips implanted. A deterioration of half a grade of the achieved MR reduction was observed 6 months post-PMVR independent of the number of implanted clips with a better stability in FMR patients, who got 3 clips compared to patients with only one clip.

Conclusions

In patients with FMR, after 6 months the reduction of MR was more stable with an increased number of implanted clips, which suggests that this specific patient collective may benefit from a higher number of clips.

Novel Aspects Targeting Platelets in Atherosclerotic Cardiovascular Disease—A Translational Perspective

Platelets are important cellular targets in cardiovascular disease. Based on insights from basic science, translational approaches and clinical studies, a distinguished anti-platelet drug treatment regimen for cardiovascular patients could be established. Furthermore, platelets are increasingly considered as cells mediating effects “beyond thrombosis”, including vascular inflammation, tissue remodeling and healing of vascular and tissue lesions. This review has its focus on the functions and interactions of platelets with potential translational and clinical relevance. The role of platelets for the development of atherosclerosis and therapeutic modalities for primary and secondary prevention of atherosclerotic disease are addressed. Furthermore, novel therapeutic options for inhibiting platelet function and the use of platelets in regenerative medicine are considered.

[What is confirmed in the treatment of atrial fibrillation?]

Atrial fibrillation is the most common clinically relevant cardiac arrhythmia. Important goals in the treatment of atrial fibrillation are improvement of the quality of life, relief of symptoms and the prevention of stroke. New in the current European guidelines on atrial fibrillation from 2020 is a structured approach with the introduction of the 4S-AF scheme (4S estimation of the risk of stroke, severity of symptoms, degree of severity of atrial fibrillation load and substrate, AF atrial fibrillation) for better characterization of atrial fibrillation and the ABC pathway in the treatment. The decision on the use of anticoagulation should be made after appropriate risk stratification. Depending on the characterization and symptoms of atrial fibrillation, the planning of further treatment should be made with respect to symptom control. Based on recent studies, rhythm-maintaining treatment by means of drugs or catheter ablation is gaining in importance over a strategy purely aimed at controlling the frequency. Integral components of treatment are also the identification and treatment of comorbidities and cardiovascular risk factors as well as the modification of an unhealthy lifestyle.

Severe Acute Respiratory Distress Syndrome (ARDS) or Severely Increased Chest Wall Elastance?

Esophageal manometry can be used to calculate transpulmonary pressures and optimize ventilator settings accordingly. We present the case of a 31-year-old male patient with ataxia-telangiectasia (Louis-Bar syndrome) and a BMI of 20 kg/m², admitted to our intensive care unit for coronavirus disease 2019 (COVID-19) pneumonia. The patient soon required mechanical ventilation; however, there was very poor respiratory system compliance. Cholecystitis complicated the clinical course, and veno-venous extracorporeal membrane oxygenation (ECMO) was initiated as gas exchange deteriorated. Esophageal manometry was introduced and revealed severely increased intrathoracic pressure and chest wall elastance.

[Subjective well-being and ability to work of hospital staff after SARS-CoV2 immunization with the mRNA vaccine BNT162b2]

BACKGROUND

 Since December 27, 2020, employees of the health system in Germany have been vaccinated against the SARS coronavirus-2 with the vaccine BNT162B2. Initial observations show that especially among younger vaccinated people side effects are common. In this study, using the example of clinic employees, the self-perceived well-being after the first and second dose of the vaccine was examined.

METHODS

 Anonymized online questionnaire to be filled out once by all employees after the second dose of BNT162B2 was offered. The severity of side effects was queried using an ordinal numerical rating scale with values between 0 and 10. Other key data points were age, gender, and occupational group. The ability to work in the days following the injections was recorded by self-reporting.

RESULTS

 Data from 555 respondents were evaluated. The mean age was 40.25 years (standard deviation 12.35). 56 % of the respondents were female, 44.3 % belonged to the medical service, 42.9 % to the nursing service and 12.8 % were assigned to other professional groups with COVID-19 patient contact. Around 2 % of all employees did not experience any side effects at all. The most common side effect was pain at the injection site. Fatigue, headaches and myalgia followed with decreasing frequency. After the first dose, ¾ of the respondents said they had tolerated the vaccination well overall, after the second dose it was only half. After the first dose, over 90 % of the respondents felt that they were able to work again on the following day, after the second dose one third stated that they were only able to work again on the second day. 2.2 % of all employees had to report that they were unable to work for at least one day after the first dose and 19.5 % after the second dose.

CONCLUSIONS

 Vaccination with BNT162B2 frequently leads to side effects, especially after the second dose. Perception of side effects resulted in 19 % of those questioned being sick after the second dose. Nevertheless, 95 % of all respondents would choose a coronavirus vaccination again.

[Interdisciplinary aspects of oral anticoagulation with NOACs in atrial fibrillation]

Stroke prophylaxis with non-vitamin K-dependent oral anticoagulants (NOAKs) in patients with non-valvular atrial fibrillation (nvVHF) is now firmly established in routine clinical practice. The definition of nvVHF includes the absence of a mechanical heart valve and AF not associated with moderate- or high-grade mitral valve stenosis. The management of oral anticoagulation (OAC) requires a high degree of interdisciplinarity. Not least for this reason, uncertainties are repeatedly observed in practice, which can have far-reaching consequences for the individual patient. For this reason, a committee consisting of representatives from general medicine, geriatrics, cardiology, nephrology and neurology has gathered to identify aspects of practical relevance from the various disciplines and to jointly develop practical guidelines to improve therapy safety for patients in everyday life.

[Treatment of benign prostatic hyperplasia in geriatric patients-use and limitations of existing guidelines]

The demographic developments of western society and the resulting increase in the number of very old patients in urology represents a challenge for the design of clinical studies and, consequently, recommendations of guidelines. While in internal medicine there is already a subspecialization with a focus on the treatment of elderly and multimorbid patients, in urology there is hardly any subspecialization into the problems of geriatric patients. Thus, using a case study as an example, the treatment decisions for benign prostatic hyperplasia (BPH) in geriatric patients are discussed. In addition the available evidence from the literature and guidelines are presented in order to assiste in daily management of geriatric patients with lower urinary tract symptoms and to critically discuss potential fields of application and limitations of the existing guidelines. In this context, we also examine the challenges when choosing a drug therapy and in deciding which of the many surgical options should be used.

Abstract 362: Acute Exposure to Air Pollution Aggravates Acute Myocardial Infarction and Subsequent Ischemic Heart Failure in Mice

Background: Clinical, but not experimental evidence has suggested that exposure to air pollution particulate matter (PM) aggravates myocardial infarction (MI) in humans. Here, we aimed to describe mechanisms and consequences of an acute PM exposure in an experimental mouse model of MI.

Methods and Results: C57BL/6J mice were exposed to an air pollution particulate matter (PM) surrogate (Residual Oil Fly Ash) by intranasal installation, prior to surgical permanent ligation of the left anterior descending coronary artery (LAD). Mice exposed to PM showed exaggerated ischemic heart failure with decreased fractional shortening and diastolic dilatation in echocardiography 6 month after MI. Histological analysis demonstrated an increase in the infarct area by 45 ± 12 % and enhanced inflammatory cell recruitment into the myocardium of PM-exposed mice 6 days after MI. Augmented cell recruitment was caused by increased activation of circulating myeloid and vascular endothelial cells. Consistently, PM exposure increased leukocyte recruitment a model of sterile peritonitis and in intravital microscopy. Mechanistically, PM exposure potentiated levels of circulating pro-inflammatory cytokines, such as of TNF-α by up to 327 ± 100 %. Increased activation of endothelial cells and leukocytes could be reversed by TNF-α antibody blockade. We identified alveolar macrophages as primary source of elevated cytokine production. Accordingly, specific in vivo depletion of lung macrophages by clodronate inhibited cytokine secretion, abolished leukocyte recruitment in intravital microscopy, and protected from cardiac inflammation after simultaneous PM exposure. Conversely, lymphocyte-free Rag1 -/- mice where susceptible to PM, indicating that alveolar macrophages, but not lymphocytes, are the cause of the systemic inflammatory response following air pollution.

Conclusion: Our data demonstrate that an acute exposure to environmental PM worsens MI and its clinical outcome in mice. These findings provide a novel functional link between air pollution and inflammatory pathways, and emphasize the importance of environmental factors in cardiovascular disease.

Binding of CD40L to Mac-1's I-domain involves the EQLKKSKTL motif and mediates leukocyte recruitment and atherosclerosis--but does not affect immunity and thrombosis in mice

RATIONALE

CD40L figures prominently in chronic inflammatory diseases such as atherosclerosis. However, since CD40L potently regulates immune function and hemostasis by interaction with CD40 receptor and the platelet integrin GPIIb/IIIa, its global inhibition compromises host defense and generated thromboembolic complications in clinical trials. We recently reported that CD40L mediates atherogenesis independently of CD40 and proposed Mac-1 as an alternate receptor.

OBJECTIVE

Here, we molecularly characterized the CD40L-Mac-1 interaction and tested whether its selective inhibition by a small peptide modulates inflammation and atherogenesis in vivo.

METHODS AND RESULTS

CD40L concentration-dependently bound to Mac-1 I-domain in solid phase binding assays, and a high-affinity interaction was revealed by surface-plasmon-resonance analysis. We identified the motif EQLKKSKTL, an exposed loop between the α1 helix and the β-sheet B, on Mac-1 as binding site for CD40L. A linear peptide mimicking this sequence, M7, specifically inhibited the interaction of CD40L and Mac-1. A cyclisized version optimized for in vivo use, cM7, decreased peritoneal inflammation and inflammatory cell recruitment in vivo. Finally, LDLr(-/-) mice treated with intraperitoneal injections of cM7 developed smaller, less inflamed atherosclerotic lesions featuring characteristics of stability. However, cM7 did not interfere with CD40L-CD40 binding in vitro and CD40L-GPIIb/IIIa-mediated thrombus formation in vivo.

CONCLUSIONS

We present the novel finding that CD40L binds to the EQLKKSKTL motif on Mac-1 mediating leukocyte recruitment and atherogenesis. Specific inhibition of CD40L-Mac-1 binding may represent an attractive anti-inflammatory treatment strategy for atherosclerosis and other inflammatory conditions, potentially avoiding the unwanted immunologic and thrombotic effects of global inhibition of CD40L.

Occlusion of iatrogenic pseudoaneurysms with percutaneous ultrasound guided thrombin injection

BACKGROUND

Pseudoaneurysm is a common complication of cardiac catheterization and coronary intervention with an incidence of 2% even in experienced centers.

PATIENTS AND METHODS

In a feasibility study conducted between December 2004 and February 2006 we enrolled 76 patients consecutively to receive local thrombin injection (mean 329 IU; range 100-800 IU) into the aneurysma sac.

RESULTS

Ultrasound guided thrombotic occlusion of pseudoaneurysms was successful after one injection in 83% of the patients, 17% of the patients required more than one injection. The overall success rate of the procedure was 98,9%. No peripheral embolisation of thrombin was noted during any injection and we registered no other complication that needed any further intervention.

CONCLUSIONS

We conclude that ultrasound guided occlusion of pseudoaneurysms using thrombin injection with a success rate of the procedure of 98,9% is feasible and safe.

Spatial distribution patterns of interphase centromeres during retinoic acid-induced differentiation of promyelocytic leukemia cells

BACKGROUND

The pericentromeric heterochromatin is an important element for the regulation of gene silencing. Its spatial distribution during interphase appears to be cell-type specific. This study analyzes three-dimensional (3D) centromere distribution patterns during cellular differentiation along the neutrophil pathway.

METHODS

Differentiation of the promyelocytic leukemia cell line NB4 was induced by retinoic acid. Centromeres in interphase nuclei were visualized by immunofluorescence staining of centromere-associated proteins with CREST serum. 3D images of nuclei were obtained by confocal microscopy. Automated methods for the segmentation of point-like objects in 3D images were implemented to detect the position of centromeres. Features of centromere localization patterns were determined by constructing the minimal spanning tree of the centromere distribution.

RESULTS

In differentiated NB4 cells, the number of centromere conglomerates (chromocenters) was decreased and the distance between chromocenters was increased as compared with untreated controls. The nuclear volume did not differ between the two groups.

CONCLUSIONS

The measured rearrangement of centromeres indicates a progressive clustering of heterochromatin and a global remodeling of interphase chromosome territories during differentiation of NB4 cells. The developed methods for the analysis of 3D centromere distribution patterns provide the opportunity for a fast and objective analysis of heterochromatin remodeling.

Integrin-mediated differentiation of a pancreatic carcinoma cell line is independent of FAK or MAPK activation levels

INTRODUCTION

The extracellular matrix (ECM) plays a salient role for proliferation and differentiation of epithelial cells. It was demonstrated that cell-ECM interactions mediated through integrins control gene expression and the tissue phenotype even in malignant tumors. Alterations of the ECM are a key feature of ductal adenocarcinoma of the pancreas.

AIMS

To examine the role of integrins and related signaling events for differentiation.

METHODOLOGY AND RESULTS

We established an in vitro model for ECM-induced differentiation of poorly differentiated pancreatic carcinoma cells and found that a specific pattern of ECM proteins resembling basal laminas (matrigel) induces differentiation of the PaTu-II pancreatic carcinoma cell line to a ductal phenotype. Both beta1- and beta4-integrins are required for cellular differentiation. Integrin-associated signaling events include activation of pp125 focal adhesion kinase (FAK) and mitogen-activated protein kinases (MAPKs) such as extracellular signal-regulated kinases (ERKs) and c-Jun NH2-terminal kinases (JNKs). However, beta1- and beta4-integrin-mediated differentiation of PaTu-II cells was independent from FAK, ERK, and JNK activation levels. Inhibition of MAPK kinases by PD98059 led to a reduction of proliferation but did not interfere with cellular differentiation of PaTu-II cells on matrigel.

CONCLUSION

The integrin-mediated differentiation of PaTu-II cells is regulated and maintained through FAK- and MAPK-independent signal transduction pathways.