New recommendations on cerebral venous and dural sinus thrombosis from the German consensus-based (S2k) guideline

Over the last years, new evidence has accumulated on multiple aspects of diagnosis and management of cerebral venous and dural sinus thrombosis (CVT) including identification of new risk factors, studies on interventional treatment as well as treatment with direct oral anticoagulants. Based on the GRADE questions of the European Stroke Organization guideline on this topic, the new German guideline on CVT is a consensus between expert representatives of Austria, Germany and Switzerland. New recommendations include:• CVT occurring in the first weeks after SARS-CoV-2 vaccination with vector vaccines may be associated with severe thrombocytopenia, indicating the presence of a prothrombotic immunogenic cause (Vaccine-induced immune thrombotic thrombocytopenia; VITT).• D-dimer testing to rule out CVT cannot be recommended and should therefore not be routinely performed.• Thrombophilia screening is not generally recommended in patients with CVT. It should be considered in young patients, in spontaneous CVT, in recurrent thrombosis and/or in case of a positive family history of venous thromboembolism, and if a change in therapy results from a positive finding.• Patients with CVT should preferably be treated with low molecular weight heparine (LMWH) instead of unfractionated heparine in the acute phase.• On an individual basis, endovascular recanalization in a neurointerventional center may be considered for patients who deteriorate under adequate anticoagulation.• Despite the overall low level of evidence, surgical decompression should be performed in patients with CVT, parenchymal lesions (congestive edema and/or hemorrhage) and impending incarceration to prevent death.• Following the acute phase, oral anticoagulation with direct oral anticoagulants instead of vitamin K antagonists should be given for 3 to 12 months to enhance recanalization and prevent recurrent CVT as well as extracerebral venous thrombosis.• Women with previous CVT in connection with the use of combined hormonal contraceptives or pregnancy shall refrain from continuing or restarting contraception with oestrogen-progestagen combinations due to an increased risk of recurrence if anticoagulation is no longer used.• Women with previous CVT and without contraindications should receive LMWH prophylaxis during pregnancy and for at least 6 weeks post partum.Although the level of evidence supporting these recommendations is mostly low, evidence from deep venous thrombosis as well as current clinical experience can justify the new recommendations.This article is an abridged translation of the German guideline, which is available online.

Venous thrombosis following endovenous laser ablation with and without thromboprophylaxis

OBJECTIVE

Venous thromboembolism (VTE) occurs infrequently after endovenous laser ablation (EVLA). The purpose of this study was to assess the incidence of VTE after EVLA with and without pharmacologic prophylaxis.

METHODS

From October 2019 to March 2020, a series of consecutive patients from the prospectively maintained VEINOVA (vein occlusion with various techniques) registry was retrospectively analyzed. All the patients underwent EVLA with and without postoperative thromboprophylaxis. A 1470-nm laser wavelength with a radial fiber was used for EVLA. Concomitant phlebectomy or sclerotherapy of insufficient tributaries was allowed. Perivenous tumescence was applied with 1% Rapidocaine (lidocaine hydrochloride monohydrate; Sintetica SA). Ablation of varicose veins was performed by continuously drawing back the laser fiber at a power of 10 W, aiming for a linear endovenous energy delivery of 60 to 90 J/cm. Compression stockings were applied postoperatively, and the patients were advised to wear them for 1 week. Duplex ultrasound was performed at the 1- and 4-week follow-up visits to determine the occlusion rate and the occurrence of EHIT and VTE.

RESULTS

Overall, 249 patients were identified from the registry. Of the 249 patients, 26 were omitted because of treatment of recurrent varicose veins. Finally, 223 consecutive patients with 223 legs and 227 saphenous veins (159 great saphenous veins, 49 small saphenous veins, and 19 anterior accessory saphenous veins) were included in the final analysis. Their mean age was 58.1 ± 13.8 years, and 167 patients (73.1%) were women. The clinical CEAP (clinical, etiology, anatomy, pathophysiology) classification was C2 for 11 legs (4.9%), C3 for 123 legs (55.2%), C4a or C4b for 86 legs (38.6%), and C5 to C6 for 3 legs (1.4%). Thromboprophylaxis was given to 132 patients (59.2%) for 3 days (rivaroxaban 10 mg once daily to 130 patients [98.5%] and low-molecular-weight heparin to 2 patients [1.5%]). No thromboprophylaxis was administered to 91 patients (40.8%) after EVLA. The average treatment length was 34.2 ± 19.3 cm and the average diameter was 5.0 ± 1.3 mm. At 1 week of follow-up, no thrombotic event had occurred in either group. At 4 weeks of follow-up, one case of EHIT class 2 (1.1%) and one case of pulmonary embolism (1.1%) had occurred in the group without thromboprophylaxis. In the thromboprophylaxis group, one deep vein thrombosis (0.8%) event had occurred (adjusted P = .135). At 1 and 4 weeks of follow-up, the treated varicose veins remained occluded in both groups.

CONCLUSIONS

Endovenous ablation of truncal varicose veins appears to be safe with a low thrombotic event rate with or without pharmacologic thromboprophylaxis. However, more data are needed before a final recommendation regarding the best thromboprophylaxis treatment option can be given.

Men with erectile dysfunction (ED) should be screened for cardiovascular risk factors - Cost-benefit considerations in Swiss men

Background: Current evidence indicates that erectile dysfunction (ED) is an independent risk factor for future cardiovascular events. This study aimed to estimate the cost-effectiveness of screening and subsequent preventive treatment for cardiovascular risk factors among men newly diagnosed with ED from the Swiss healthcare system perspective. Methods: Based on known data on ED and cardiovascular disease (CVD) prevalence and incidence costs and effects of a screening intervention for cardiovascular risk including corresponding cardiovascular prevention in men with ED were calculated for the Swiss population over a period of 10 years. Results: Screening and cardiovascular prevention over a period of 10 years in Swiss men with ED of all seriousness degrees, moderate and severe ED only, or severe ED only can probably avoid 41,564, 35,627, or 21,206 acute CVD events, respectively. Number needed to screen (NNS) to prevent one acute CVD event is 30, 23, and 10, respectively. Costs for the screening intervention are expected to be covered at the seventh, the fifth, and the first year, respectively. Conclusion: Screening and intervention for cardiovascular risk factors in men suffering from ED is a cost-effective tool not only to strengthen prevention and early detection of cardiovascular diseases but also to avoid future cardiovascular events.

Erectile dysfunction: role of computed tomography cavernosography in the diagnosis and treatment planning of venous leak

BACKGROUND

Venous leak appears to be the most common cause of vasculogenic erectile dysfunction (ED), which can be treated with venous embolization. Traditionally, conventional cavernosography was used for the diagnosis and treatment planning of venous leak. Recently, computed tomography (CT) cavernosography was introduced as a novel cross-sectional imaging method proposed to be advantageous over conventional cavernosography. We created a novel management algorithm for diagnosing venous leak including CT cavernosography as an imaging modality. In order to provide a broader basis for our management algorithm, a systematic literature review was conducted.

MAIN BODY

In this article we systematically review relevant literature on using CT cavernosography for the diagnosis and treatment planning in ED patients with venous leak following the PRISMA selection process. Nine full-text articles were included in the review and assigned a level of evidence grade (all grade II). Two studies (2/9) compared the results of conventional cavernosography with those of CT cavernosography which was superior for site-specific venous leak identification (19.4% vs. 100%, respectively). CT cavernosography is a more detailed imaging method that is faster to perform, exposes the patient to less radiation, and requires less contrast material. In one study (1/9), CT cavernosography was used for diagnostic purposes only. Eight studies (8/9) cover both, diagnostic imaging and treatment planning including embolization (1/9) and sclerotherapy (2/9) of venous leak in patients with venogenic ED. Three studies (3/9) describe anatomical venous leak classifications that were established based on CT cavernosography findings for accurate mapping of superficial and/or deep venous leak and identification of mixed or more complex forms of venous leak present in up to 84% of patients. In addition to treatment planning, one study (1/9) used CT cavernosography also for follow-up imaging post treatment.

CONCLUSION

CT cavernosography is superior to conventional cavernosography for diagnosis and treatment planning in patients with ED caused by venous leak (grade II levels of evidence). Consequently, CT cavernosography should be included in management algorithms for ED patients with suspected venous leak.

Long-Term Outcomes of Drug-Eluting Stent Implantation for Patients With Atherosclerotic Erectile Dysfunction not Responding to PDE-5-Inhibitors

PURPOSE

Endovascular therapy of erection-related arteries was shown to be a promising treatment option for patients with severe erectile dysfunction. Purpose of this study was to assess the longer-term safety and clinical success rate of endovascular revascularization of erection-related arteries with the Angiolite BTK stent in patients with arteriogenic erectile dysfunction.

MATERIALS AND METHODS

A total of 147 consecutive men (63.5±9.3 years) with erectile dysfunction due to 345 atherosclerotic lesions underwent endovascular revascularization. Patients received an International Index of Erectile Function (IIEF)-15 questionnaire at 30.3±7.2 months (follow-up [FU] period no less than 18 months) after stenting. An improvement by 4 points in the erectile function domain consisting of 6 questions (IIEF-6) was defined as minimal clinically important difference (MCID).

RESULTS

Technical success was achieved in 99% of lesions. One major adverse event occurred after endovascular revascularization. Sixty-eight (46%) patients completed their latest FU at least 18 months following the last intervention. Minimal clinically important difference was achieved in 54% (37/68) of patients.

CONCLUSIONS

In patients with arteriogenic erectile dysfunction not responding to phosphodiesterase-5-inhibitors (PDE-5-Is), endovascular therapy with a novel thin-strut sirolimus-eluting stent is a safe and effective treatment option during short- and longer-term FU.

CLINICAL IMPACT

Patients with severe erectile dysfunction profit greatly from endovascular therapy of erection-related arteries. Stable clinical outcomes are seen beyond a 1-year timeframe. It is proven that, the drug-eluting stent therapy for atherosclerotic ED in patients who have not responded to PDE-5-I therapy is safe and effective during longer-term follow-up.

Role of Lp(a) in patients with erectile dysfunction undergoing angioplasty for symptomatic pelvic artery disease

Background: Atherosclerotic disease of erection-related arteries is a major reason for erectile dysfunction (ED). Lp(a) has been implied in the pathophysiology of atherosclerosis in the coronary and lower limb arteries. Here, we investigated if Lp(a) plays a specific role in ED due with symptomatic pelvic artery atherosclerosis. Patients and methods: Out of 276 consecutive patients treated for ED with angioplasties on proximal (69%) and distal (31%, distal to Alcock channel) erection-related arteries, 236 patients (age: 62±10 years) of which Lp(a) values were available were retrospectively analyzed. Results: The baseline International Index of Erectile Function-15 (IIEF-15) score was 29±15 and significantly increased to 43±20 (increase: 14±21) after treatment at average follow up of 286±201 days. In 25%, Lp(a) values were elevated to more than 30 mg/dL. Hypercholesterolemia, coronary, lower extremity peripheral, and polyvascular disease were more common in patients with Lp(a) ≥60 mg/dl. Anatomic arterial lesion distribution (proximal/distal), improvement in IIEF-15 and clinically driven re-intervention rate (overall 7%) did not differ between patients with <30, 30-59, and ≥60 mg/dL Lp(a). Conclusions: While angioplasty is an effective therapy for ED of arterial origin in patients with obstruction of erection-related arteries, Lp(a) does not seem to play a major role for clinical outcomes in these patients.

Venous Leak Embolization in Patients with Venogenic Erectile Dysfunction via Deep Dorsal Penile Vein Access: Safety and Early Efficacy

PURPOSE

This all-comers registry aimed to assess safety and early efficacy of venous embolization in patients with venogenic erectile dysfunction due to venous leak in an unselected cohort.

METHODS

Between October 2019 and September 2022, patients with venogenic erectile dysfunction resistant to phosphodiesterase-5-inhibitors were treated with venous embolization using ultrasound-guided anterograde access via a deep dorsal penile vein in a single center. A mix of ethiodized oil and modified cyanoacrylate-based glue n-butyl 2 cyanoacrylate (NBCA) monomer plus methacryloxy-sulpholane monomer (Glubran-2, GEM, Italy) was used as liquid embolic agent. Prior to embolization, venous leak had been verified based on penile duplex sonography and computed tomography cavernosography. Procedural success was defined as technically successful and complete target vein embolization. The primary safety outcome measure was any major adverse event 6 weeks after the procedure. The primary feasibility outcome measure was IIEF-15 (International Index of Erectile Function-15) score improvement ≥ 4 points in ≥ 50% of subjects on 6 weeks follow-up post intervention.

RESULTS

Fifty consecutive patients (mean age 61.8 ± 10.0 years) with severe erectile dysfunction due to venous leak underwent venous embolization. Procedural success was achieved in 49/50 (98%) of patients with no major adverse events on follow-up. The primary feasibility outcome measure at 6 weeks was reached by 34/50 (68%) of patients.

CONCLUSION

Venous leak embolization via deep dorsal penile vein access using a liquid embolic agent was safe for all and efficacious in the majority of patients with severe venogenic erectile dysfunction on 6 weeks follow-up.

Frequency and anatomic distribution of arterial obstructions in patients with vasculogenic erectile dysfunction not responding to intracavernous prostaglandin

Background: The extent of arterial disease in patients with erectile dysfunction (ED) non-responsive to intracavernosal injection of Alprostadil is of importance for therapeutic options. However, published evidence, in particular angiographically validated is scarce. Here we investigated arterial lesion patterns in this specific patient cohort by selective angiography. Patients and methods: A cohort of 239 patients received a clinical and duplex-sonographic workup for ED of suspected vascular origin. Duplex ultrasound of the cavernosal arteries was performed after intracavernosal injection of 10 μg Alprostadil. Consequently, standardized workup included grading of the erectile and determination of peak systolic velocity (PSV) and end-diastolic velocity (EDV) in both cavernosal arteries. PSV-values below 30 cm/sec indicated reduced arterial flow, whereas EDV-values above 15 cm/sec indicated a venous leak of the pudendal veins. All patients with suspected arterial ED based on duplex sonography underwent contrast-enhanced computed tomography. Endovascular therapy was carried out in ED patients not responsive or with significant side effects to PDE-5-inhibitors or Alprostadil by selective angiographic depiction of erection-related arteries. Results: 54 patients with a mean age of 61.2 (±9.8) years underwent angioplasty of erectionr elated arteries. Out of these 48/54 (89%) patients presented with an erection considered insufficient for penetration (E0-E3) subsequent to intracavernous application of 10 μg Alprostadil. 14/48 (29%) patients had bilateral arterial obstructions and 34/48 (71%) had unilateral disease. Commonly affected was the internal pudendal artery (n = 31, 65%), followed closely by the common penile artery (n = 30, 64%). The least affected arteries were the dorsal penile (n = 6, 13%), hypogastric (n = 4, 8%), common iliac (n = 4, 8%), cavernosal (n = 4, 8%), and inferior gluteal (n = 1, 2%) arteries. Conclusions: Arterial obstructions amenable to endovascular revascularization are frequent in patients non-responsive to intracavernosal prostaglandin administration. Therapeutic strategies in ED patients non-responsive to conservative measures should therefore consider endovascular treatment opportunities.

Anatomie der Arterien: Untere Extremität

Anatomie, Morphologie und Hämodynamik sind elementare Bausteine der Gefäßmedizin. Insbesondere die Kenntnis der Anatomie der Arterien der unteren Extremität ist für weiterführende diagnostische Maßnahmen wie die farbkodierte Duplexsonografie von großer Bedeutung. Der vorliegende Artikel zeigt pragmatisch in parallelen Bildern den anatomischen Verlauf der Beinarterie zum Skelett, die Projektion der Anatomie auf die Haut mit der erforderlichen Schallkopfführung und den sonografischen Normalbefund.

Demographic and procedural characteristics in the RECording COurses of vasculaR Diseases (RECCORD) registry – the first 1000 patients

Summary: Background: The RECcording COurses of vasculaR Diseases (RECCORD) registry established by the German Society of Angiology – Society for Vascular Medicine aimed to address the lack in contemporary real-world data regarding current practice of medical and interventional care in vascular patients. We herein report the demographic and procedural characteristics of the first 1000 patients undergoing endovascular revascularization (EVR) for symptomatic peripheral artery disease (PAD). Patients and methods: RECCORD is an observational, prospective, multicenter, all-comers registry. Only patients undergoing EVR for symptomatic PAD are included and followed up for at least 1 year. Demographic characteristics, comorbidities, previous peripheral vascular interventions, medication, clinical stage of lower extremity artery disease (Rutherford category), hemodynamic parameters, and procedural data including complications are recorded via an entirely web-based platform. Results: Of the first 1000 patients (mean age 70 ± 10 years, 35% female) with 1096 EVR at 1477 vascular segments of the lower extremities, 25.0% were at the stage of chronic limb threatening ischemia (CLTI) and 75.0% at non-CLTI. The femoropopliteal segment was the dominant target lesion site (61.0%), followed by iliac (26.4%) and below-the-knee EVR (10.3%). Only angioplasty was performed in 130 EVR (11.9%), adjunctive drug coated balloons (DCB) in 498 (45.4%), additional stenting in 633 (57.8%). Debulking devices were used in 106 (9.7%) EVR. Clinical (Rutherford categories) and hemodynamic parameters (ankle-brachial-index) as well as secondary preventive medication were significantly improved post EVR. Periprocedural complications occurred in 63 (5.7%) EVR with pseudoaneurysm as the leading complication type in 26 (2.4%) EVR. Conclusions: The baseline data of the first 1000 patients from the RECCORD registry representing the real-world setting illustrate that the majority of EVR are performed in patients with claudication. Adjunctive use of DCB and stenting are the dominant types of EVR, while periprocedural complications are at an acceptable low rate.

Incidental findings during computed tomographic angiography diagnostic work-up in patients with arteriogenic erectile dysfunction

AIM

To analyse the incidental findings during computed tomographic angiography (CTA) diagnostic work-up in patients with arteriogenic erectile dysfunction (ED).

PATIENTS AND METHODS

The medical records of all patients with suspected arteriogenic ED were entered into a database. Risk factors and underlying comorbidities were also collected. Pathological CTA findings were extracted from the CT readings and entered into the database. Incidental findings on CTA were classified as those requiring immediate medical treatment, requiring deferred medical treatment or of no clinical importance.

RESULTS

A total of 200 patients underwent CTA for suspected arteriogenic ED. Mean patient age was 59.6 &plusmn; 11.7 years. Of these, 181 patients (90.5%) had obstructions of erection-related arteries. In 168 patients (84.0%), CTA showed multiple incidental pathological findings. Eighty-five of 200 patients (42.5%) exhibited incidental findings requiring immediate further medical workup and/or treatment: coronary artery calcification was diagnosed in 75/200 (37.5%), aorto-iliac aneurysms in 8/200 (4%) of patients and incidentally detected embolism in 1/200 patient. Pancreatic and liver tumours were less frequent (incidence 1.5% and 1%, respectively). Incidental findings requiring deferred medical workup and/or treatment were detected in 175/200 patients (87.5%). The findings with the highest prevalence were liver steatosis followed by colon diverticulosis and prostate hyperplasia. Findings of little to no clinical importance were reported in 117 (58.5%) patients. These included uncomplicated renal cysts, spinal degeneration and renal vascular anomalies. Almost every second patient presenting with ED had an incidental finding which required immediate treatment.

CONCLUSIONS

Incidental findings not directly related to ED were common among patients undergoing CTA scans for suspected arterial obstructions. Coronary artery calcification was the leading finding requiring further medical workup and/or treatment. Thus, the benefit of CTA investigations extends beyond the anatomic description of arterial obstructions of erection-related arteries.

Arteriell bedingte Beinschmerzen

In der differentialdiagnostischen Abwägung von Beinschmerzen spielen arterielle Gefäßerkrankungen eine wichtige Rolle. Nicht selten allerdings werden in der täglichen Arztpraxis zunächst orthopädische und neurologische Ursachen in Erwägung gezogen. Ein Grund ist sicher die facettenreiche Symptomatik und die Heterogenität arterieller Durchblutungsstörungen.

Obwohl arteriell bedingte Schmerzen der Beine überwiegend arteriosklerotischer Genese sind, sollte das Vorliegen nicht-arteriosklerotischer Ursachen wie die Embolie, die Gefäßdissektion, Kompressionssyndrome und inflammatorische Erkrankungen immer in Erwägung gezogen werden. Prognoseentscheidend ist das Erkennen einer arteriell bedingten Problematik, die Abschätzung des Schweregrades der Durchblutungsstörung und dadurch auch des Amputationsrisikos der Extremität sowie ein zügiges Management.

Treatment of the antiphospholipid syndrome with direct oral anticoagulantsPosition statement of German societies

The antiphospholipid-syndrome (APS) is one of the most severe forms of thrombophilia, which may not only lead to recurrent venous but also to arterial thromboembolic events (TE), and to severe pregnancy complications, respectively. APS is defined by clinical symptoms and specific laboratory findings: 1. Lupus anticoagulant (LA), 2. anticardiolipin-antibodies (ACA), and 3. β2-Glycoprotein I-antibodies (β2GPI-Ab). All test results have to be confirmed after at least 12 weeks. The thrombotic risk is highest, if all 3 test groups are positive. It must be pointed out that the presence of UFH, VKA or DOACs may lead to false positive LA-test results; the addition of a specific absorber after blood sampling may provide reliable results in the presence of DOACs. A prospective randomized controlled trial comparing warfarin and rivaroxaban (TRAPS-trial) including only high-risk patients with triple positive APS was terminated early because of an increased rate of TE in patients treated with rivaroxaban [19 %, mostly arterial, compared to 3 % with warfarin (HR 7.4;1.7-32.9)]. Subsequently, a warning letter was issued by the pharmaceutical manufacturers of DOACs, including a warning of DOAC use in APS-patients, particularly in triple-positive high-risk patients. Conclusions: 1. Clinical suspicion of APS requires careful diagnostic testing. Because of inadequate diagnostic workup, many patients may not even have an APS, and these patients could be adequately treated with a DOAC. 2. Patients with single or double positive antiphospholipid antibodies but without positive LA may have a comparably low thrombotic risk and may also be treated with a DOAC in venous TE - sufficient evidence for that conclusion is not yet available but is suggested by the results of meta-analyses. 3. Triple positive patients or those with APS who suffered from arterial thromboembolism have a very high recurrence risk of thrombosis; the TRAPS-Study shows that these patients should be treated with VKA instead of a DOAC.

Therapie des Antiphosphoplidsyndrom (APS) mit DOAK

Das Antiphospholipid-Syndrom ist eine der schwerwiegendsten thrombophilen Störungen, die nicht nur zu rezidivierenden venösen, sondern auch zu arteriellen Thromboembolien sowie Schwangerschaftskomplikationen führen kann. Zusammen mit dem klinischen Bild ist das APS durch spezifische Laborbefunde charakterisiert: 1. Lupus Antikoagulans (LA), 2. Anticardiolipin-Antikörper (ACA), 3. β2-Glykoprotein I-Antikörper (β2GPI-AK). Alle Testergebnisse müssen nach 12 Wochen bestätigt werden. Sind alle drei Testgruppen positiv, besteht das höchste thrombotische Risiko. Beachtet werden muss, dass LA-Tests unter UFH, VKA oder DOAKs falsch positiv ausfallen können; bei DOAKs scheint die Zugabe von Absorbern nach Blutentnahme zuverlässige Ergebnisse zu liefern.

Eine Vergleichsstudie (TRAPS) zwischen VKA und dem DOAK Rivaroxaban mit ausschliesslich 3-fach positiven Hochrisiko-Patienten wurde vorzeitig abgebrochen, wegen erhöhter Ereignisraten unter Rivaroxaban [19 % zumeist arterielle Ereignisse versus 3 % unter Warfarin (HR 7.4; 1.7–32.9)]. Ein daraufhin herausgegebener Rote-Hand-Brief warnt vor der Anwendung von DOAKs bei Patienten mit APS, insbesondere bei Hoch-Risiko- (3-fach positiven) Patienten, und empfiehlt die Überprüfung einer laufenden DOAK-Therapie und eine mögliche Umstellung auf VKA, insbesondere bei Hoch-Risiko-Patienten. Als Fazit soll 1. bei klinischem Verdacht eine sorgfältige APS-Diagnostik erfolgen. Viele Patienten haben aufgrund von inadäquater Diagnostik wahrscheinlich gar kein APS und können bei venöser Thromboembolie adäquat ein DOAK erhalten.

2. Bei einfach- oder zweifach-positiven Antiphospholipid-AK Tests ohne LA besteht ein vergleichbar niedriges Thromboserisiko; auch hier kann möglicherweise ebenfalls mit DOAKs behandelt werden, wenn venöse Thrombosen vorliegen – ausreichende Daten liegen noch nicht vor, aber Metaanalysen legen dies nahe. 3. Patienten mit Positivität in allen 3 APS-Tests und APS-Patienten mit arteriellen Thromboembolien haben ein sehr hohes Risiko. Die TRAPS-Studie zeigt, dass diese Patienten nicht mit DOAKs, sondern mit einem VKA behandelt werden sollen.

[Peripheral Arterial Disease: When is a PCSK9 Inhibitor Useful?]

The guideline of the European Society of Cardiology recommends an LDL-C target < 70 mg/dL or a 50 % reduction in patients with manifest peripheral arterial disease (PAD) as well as in CHD or cerebrovascular disease when the baseline LDL-C is between 70 and 135 mg/dL. Application of a PCSK9 inhibitor allows target attainment for those patients who do not achieve this under maximal conventional therapy with a statin in combination with ezetemib. In the Fourier study, patients with PAOD who had neither a myocardial infarction nor a stroke at admission of the study had a significant risk reduction (RR) of both cardiovascular (RR = 0.67, 0.47 - 0.96, p = 0.0283) as well as extremity endpoints (RR = 0.43 (0.19 - 0.99; p = 0.042). In Germany these patients are primarily seen by angiologists. This group of vascular specialists is specifically mentioned in the decision of the Federal Joint Committee as one of those who may indicate treatment with PCSK9 inhibitors.

Cell-based therapy facilitates venous thrombus resolution

Endothelial progenitor cells (EPC) are involved in many healing processes in cardiovascular diseases and can be found in spontaneously resolving venous thrombi. The purpose of the present study was to investigate whether the therapeutic administration of EPC might enhance the resolution of venous thrombi. For this purpose, venous thrombosis was induced in the infrarenal inferior vena cava (IVC) in 28 athymic nude rats. Culture expanded EPC derived from human peripheral blood mononuclear cells were injected intravenously two and four days after thrombus induction. Recanalisation of the IVC and thrombus organisation were assessed by laser Doppler measurements of the blood flow and immunohistochemical detection of endothelialised luminal structures in the thrombus. EPC transplantation resulted in significantly enhanced thrombus neovascularisation (capillary density: 186.6 ± 26.7/HPF vs. 78 ± 12.3/HPF, p<0.01; area covered by capillaries: 8.9 ± 1.7 µm2 vs. 2.5 ± 1.3 µm2, p<0.01) and was accompanied by a substantial increase in intrathrombus blood flow (perfusion ratio: 0.7 ± 0.07 vs. 0.3 ± 0.08, p<0.02). These results were paralleled by augmented macrophage recruitment into resolving thrombi in the animals treated with EPC (39.4 ± 4.7/HPF vs. 11.6 ± 1.9/HPF, p<0.01). Our data suggest that EPC transplantation might be of clinical value to facilitate venous thrombus resolution in cases where current therapeutic options have limited success.

Influence of Pulmonary Status and Diabetes Mellitus on Aortic Neck Dilatation following Endovascular Repair of Abdominal Aortic Aneurysms: A EUROSTAR Report

Purpose:

To elucidate the association of impaired pulmonary status (IPS) and diabetes mellitus (DM) with clinical outcome and the incidences of aortic neck dilatation and type I endoleak after elective endovascular infrarenal aortic aneurysm repair (EVAR).

Methods:

In 164 European institutions participating in the EUROSTAR registry, 6383 patients (5985 men; mean age 72.4±7.6 years) underwent EVAR. Patients were divided into patients without versus with IPS or with/without DM. Clinical assessment and contrast-enhanced computed tomography (CT) were performed at 1, 3, 6, 12, 18, and 24 months and annually thereafter. Cumulative endpoint analysis comprised death, aortic rupture, type I endoleak, endovascular reintervention, and surgical conversion.

Results:

Prevalence of IPS was 2733/6383 (43%) and prevalence of DM was 810/6383 (13%). Mean follow-up was 21.1±18.4 months. Thirty-day mortality, AAA rupture, and conversion rates did not differ between patients with versus without IPS and between patients with versus without DM. All-cause and AAA-related mortality, respectively, were significantly higher in patients with IPS compared to patients with normal pulmonary status (31.0% versus 19.0%, p<0.0001 and 6.8% versus 3.3%, p=0.0057) throughout follow-up. In multivariate analysis adjusted for smoking, age, gender, comorbidities, fitness for open repair, co-existing common iliac aneurysm, neck and aneurysm size, arterial angulations, aneurysm classification, endograft oversizing >15%, and type of stent-graft, the presence of IPS was not associated with significantly higher rates of aortic neck dilatation (30.6% versus 38.0%, p>0.05) and did not influence cumulative rates of type I endoleak, endovascular reintervention, or conversion to open surgery (p>0.05). Similarly, the presence of DM did not influence the above-mentioned study endpoints.

Conclusion:

In contrast to observations regarding the natural course of AAAs, impaired pulmonary status does not negatively influence aortic neck dilatation, while the presence of diabetes does not protect from these dismal events after EVAR.

Endothelial progenitor cells as a biological marker of peripheral artery disease

The role of endothelial progenitor cells (EPCs) in peripheral artery disease (PAD) remains unclear. We hypothesized that EPC mobilization and function play a central role in the development of endothelial dysfunction and directly influence the degree of atherosclerotic burden in peripheral artery vessels. The number of circulating EPCs, defined as CD34(+)/KDR(+) cells, were assessed by flow cytometry in 91 subjects classified according to a predefined sample size of 31 non-diabetic PAD patients, 30 diabetic PAD patients, and 30 healthy volunteers. Both PAD groups had undergone endovascular treatment in the past. As a functional parameter, EPC colony-forming units were determined ex vivo. Apart from a broad laboratory analysis, a series of clinical measures using the ankle-brachial index (ABI), flow-mediated dilatation (FMD) and carotid intima-media thickness (cIMT) were investigated. A significant reduction of EPC counts and proliferation indices in both PAD groups compared to healthy subjects were observed. Low EPC number and pathological findings in the clinical assessment were strongly correlated to the group allocation. Multivariate statistical analysis revealed these findings to be independent predictors of disease appearance. Linear regression analysis showed the ABI to be a predictor of circulating EPC number (p=0.02). Moreover, the functionality of EPCs was correlated by linear regression (p=0.017) to cIMT. The influence of diabetes mellitus on EPCs in our study has to be considered marginal in already disease-affected patients. This study demonstrated that EPCs could predict the prevalence and severity of symptomatic PAD, with ABI as the determinant of the state of EPC populations in disease-affected groups.

Longitudinal Telomere Erosion in Lymphocyte Subsets of Patients with Atherosclerotic Peripheral Arterial Disease (PAD)

Telomere attrition has been linked to accelerate vascular ageing and seems to predispose for vascular disease. Our aim was to study the telomere length dynamics over time and in subsets of leukocytes from 15 patients with peripheral arterial disease (PAD). The mean telomere length in subsets of leukocytes of patients with PAD was in the normal range of age-related telomere length values from healthy individuals. However, we found significant higher telomere attrition for T-cells from patients with PAD over a time period of six months when compared to the controls. The higher telomere loss in T-cells of patients with PAD most likely reflects a higher cell turnover of this leukocyte subset, which is involved in the process of chronic inflammatory disease underlying vascular disease. Further studies are needed to confirm these data and to assess how far this T-cell telomere attrition will correlate to the extent of the disease.

Infrapopliteal lesion morphology in patients with critical limb ischemia: implications for the development of anti-restenosis technologies

PURPOSE

To angiographically evaluate infrapopliteal arterial lesion morphology in a consecutive series of patients presenting with critical limb ischemia (CLI) and undergoing infrapopliteal angioplasty.

METHODS

A prospective analysis was undertaken of a consecutive series of CLI patients undergoing endovascular therapy in a tertiary referral center in the year 2011. Morphological assessment of baseline angiograms obtained prior to revascularization included lesion length, assessment of calcification using a semi-quantitative scoring system, and reference vessel diameter (RVD) measurement. Delta RVDs were assessed subtracting distal RVDs from proximal RVDs. A total of 197 infrapopliteal lesions in 105 CLI patients (n=106 limbs) were assessed. Of these, 136 lesions were treated by endovascular means.

RESULTS

The average length of treated lesions was 87.1±43.8 mm in stenoses and 124.0±78.3 mm in chronic occlusions (p<0.001). Mean RVD proximal to the lesions was 1.88 mm whereas it was 1.66 mm distal to the lesions (p≤0.03). Mean arterial calcification was 1.15.

CONCLUSION

This prospective angiographic series underlines the complex nature and extensive longitudinal involvement of infrapopliteal lesions in CLI patients. These findings should be taken into consideration for anti-restenosis concepts in this challenging subgroup of peripheral artery disease patients.

Intraarterial administration of bone marrow mononuclear cells in patients with critical limb ischemia: a randomized-start, placebo-controlled pilot trial (PROVASA)

BACKGROUND

Critical limb ischemia due to peripheral arterial occlusive disease is associated with a severely increased morbidity and mortality. There is no effective pharmacological therapy available. Injection of autologous bone marrow-derived mononuclear cells (BM-MNC) is a promising therapeutic option in patients with critical limb ischemia, but double-blind, randomized trials are lacking.

METHODS AND RESULTS

Forty patients with critical limb ischemia were included in a multicenter, phase II, double-blind, randomized-start trial to receive either intraarterial administration of BM-MNC or placebo followed by active treatment with BM-MNC (open label) after 3 months. Intraarterial administration of BM-MNC did not significantly increase ankle-brachial index and, thus, the trial missed its primary end point. However, cell therapy was associated with significantly improved ulcer healing (ulcer area, 3.2±4.7 cm(2) to 1.89±3.5 cm(2) [P=0.014] versus placebo, 2.92±3.5 cm(2) to 2.89±4.1 cm(2) [P=0.5]) and reduced rest pain (5.2±1.8 to 2.2±1.3 [P=0.009] versus placebo, 4.5±2.4 to 3.9±2.6 [P=0.3]) within 3 months. Limb salvage and amputation-free survival rates did not differ between the groups. Repeated BM-MNC administration and higher BM-MNC numbers and functionality were the only independent predictors of improved ulcer healing. Ulcer healing induced by repeated BM-MNC administration significantly correlated with limb salvage (r=0.8; P<0.001).

CONCLUSIONS

Intraarterial administration of BM-MNC is safe and feasible and accelerates wound healing in patients without extensive gangrene and impending amputation. These exploratory findings of this pilot trial need to be confirmed in a larger randomized trial in patients with critical limb ischemia and stable ulcers.

Current developments in the use of stem cell for therapeutic neovascularisation: is the future therapy "cell-free"?

The plasticity and self-regenerative properties of stem cells have opened new avenues in regenerative medicine. Greater understanding of the biology of stem cells is followed by growing expectations of a rapid translation into alternative therapeutic options. Recent preclinical studies and clinical trials employing stem and progenitor cells from different sources have shown encouraging results. However, their underlying mechanisms are still poorly understood, the potential adverse effects and the discrepancy in efficacy remain to be further investigated. Their essential role in vessel regeneration has made endothelial progenitor cells (EPC) a suitable candidate for therapeutic applications aiming at tissue revascularisation. Recent evidence suggests that EPC contribute to neovascularisation not only by direct participation in tissue homeostasis but mainly via paracrine mechanisms. In future, novel therapeutic strategies could be based on EPC paracrine factors or synthetic factors, and replace cell transplantation.

Endothelial progenitor cells induce a phenotype shift in differentiated endothelial cells towards PDGF/PDGFRβ axis-mediated angiogenesis

Background

Endothelial Progenitor Cells (EPC) support neovascularization and regeneration of injured endothelium both by providing a proliferative cell pool capable of differentiation into mature vascular endothelial cells and by secretion of angiogenic growth factors.

Objective

The aim of this study was to investigate the role of PDGF-BB and PDGFRβ in EPC-mediated angiogenesis of differentiated endothelial cells.

Methods and Results

Conditioned medium from human EPC (EPC-CM) cultured in hypoxic conditions contained substantially higher levels of PDGF-BB as compared to normoxic conditions (P<0.01). EPC-CM increased proliferation (1.39-fold; P<0.001) and migration (2.13-fold; P<0.001) of isolated human umbilical vein endothelial cells (HUVEC), as well as sprouting of vascular structures from ex vivo cultured aortic rings (2.78-fold increase; P = 0.01). The capacity of EPC-CM to modulate the PDGFRβ expression in HUVEC was assessed by western blot and RT-PCR. All the pro-angiogenic effects of EPC-CM on HUVEC could be partially inhibited by inactivation of PDGFRβ (P<0.01). EPC-CM triggered a distinct up-regulation of PDGFRβ (2.5±0.5; P<0.05) and its phosphorylation (3.6±0.6; P<0.05) in HUVEC. This was not observed after exposure of HUVEC to recombinant human PDGF-BB alone.

Conclusion

These data indicate that EPC-CM sensitize endothelial cells and induce a pro-angiogenic phenotype including the up-regulation of PDGFRβ, thereby turning the PDGF/PDGFRβ signaling-axis into a critical element of EPC-induced endothelial angiogenesis. This finding may be utilized to enhance EPC-based therapy of ischemic tissue in future.

Impact of long-term corticosteroid therapy on the distribution pattern of lower limb atherosclerosis

OBJECTIVE

Ectopic calcification and mediacalcinosis can be promoted by corticosteroid use. Aim of the present investigation is to describe macrovascular disease features in patients with long-term corticosteroid therapy and symptomatic lower limb peripheral arterial occlusive disease (PAD).

METHODS

A consecutive series of 2783 patients undergoing clinical and angiographic work-up of PAD were screened for long-term (>5 years) corticosteroid use (group A). Comparison was performed to a randomly selected age-, sex- and risk factor-matched PAD control cohort from the same series without corticosteroid use (group B). Patients with diabetes mellitus or severe renal failure were excluded. Arterial calcification was evaluated by qualitative assessment on radiographic images. Severity of atherosclerotic lesions was analysed from angiographic images using a semi-quantitative score (Bollinger score).

RESULTS

In general, 12 patients (5 males, mean age 78.5 +/- 9.0 years) with 15 ischaemic limbs qualified to be enrolled in group A and were compared to 23 matching control patients (6 2 males, mean age 79.5 +/- 6 years) with 32 ischaemic limbs. Incompressibility of ankle arteries determined by measurement of the ankle-brachial index was seen in 12 limbs (80%) in group A compared to 3 limbs (9%) in group B (p = 0.0009). No significant difference was found comparing group A and B for segmental calcification, whereas comparison of the atherosclerotic burden using the angiographic severity score showed a significantly higher score at the infragenicular arterial level in group A (p = 0.001).

CONCLUSION

Findings suggest that the long-term corticosteroid therapy is associated with a distally accentuated, calcifying peripheral atherosclerosis inducing arterial incompressibility. This occlusion pattern is comparable to patients with renal failure or diabetes. Further research is required to support our observations.

Lack of extended venous thromboembolism prophylaxis in high-risk patients undergoing major orthopaedic or major cancer surgery. Electronic Assessment of VTE Prophylaxis in High-Risk Surgical Patients at Discharge from Swiss Hospitals (ESSENTIAL)

Extended pharmacological venous thromboembolism (VTE) prophylaxis beyond discharge is recommended for patients undergoing high-risk surgery. We prospectively investigated prophylaxis in 1,046 consecutive patients undergoing major orthopaedic (70%) or major cancer surgery (30%) in 14 Swiss hospitals. Appropriate in-hospital prophylaxis was used in 1,003 (96%) patients. At discharge, 638 (61%) patients received prescription for extended pharmacological prophylaxis: 564 (77%) after orthopaedic surgery, and 74 (23%) after cancer surgery (p < 0.001). Patients with knee replacement (94%), hip replacement (81%), major trauma (80%), and curative arthroscopy (73%) had the highest prescription rates for extended VTE prophylaxis; the lowest rates were found in patients undergoing major surgery for thoracic (7%), gastrointestinal (19%), and hepatobiliary (33%) cancer. The median duration of prescribed extended prophylaxis was longer in patients with orthopaedic surgery (32 days, interquartile range 14-40 days) than in patients with cancer surgery (23 days, interquartile range 11-30 days; p<0.001). Among the 278 patients with an extended prophylaxis order after hip replacement, knee replacement, or hip fracture surgery, 120 (43%) received a prescription for at least 35 days, and among the 74 patients with an extended prophylaxis order after major cancer surgery, 20 (27%) received a prescription for at least 28 days. In conclusion, approximately one quarter of the patients with major orthopaedic surgery and more than three quarters of the patients with major cancer surgery did not receive prescription for extended VTE prophylaxis. Future effort should focus on the improvement of extended VTE prophylaxis, particularly in patients undergoing major cancer surgery.

Novel cell-free strategy for therapeutic angiogenesis: in vitro generated conditioned medium can replace progenitor cell transplantation

BACKGROUND

Current evidence suggests that endothelial progenitor cells (EPC) contribute to ischemic tissue repair by both secretion of paracrine factors and incorporation into developing vessels. We tested the hypothesis that cell-free administration of paracrine factors secreted by cultured EPC may achieve an angiogenic effect equivalent to cell therapy.

METHODOLOGY/PRINCIPAL FINDINGS

EPC-derived conditioned medium (EPC-CM) was obtained from culture expanded EPC subjected to 72 hours of hypoxia. In vitro, EPC-CM significantly inhibited apoptosis of mature endothelial cells and promoted angiogenesis in a rat aortic ring assay. The therapeutic potential of EPC-CM as compared to EPC transplantation was evaluated in a rat model of chronic hindlimb ischemia. Serial intramuscular injections of EPC-CM and EPC both significantly increased hindlimb blood flow assessed by laser Doppler (81.2+/-2.9% and 83.7+/-3.0% vs. 53.5+/-2.4% of normal, P<0.01) and improved muscle performance. A significantly increased capillary density (1.62+/-0.03 and 1.68+/-0.05/muscle fiber, P<0.05), enhanced vascular maturation (8.6+/-0.3 and 8.1+/-0.4/HPF, P<0.05) and muscle viability corroborated the findings of improved hindlimb perfusion and muscle function. Furthermore, EPC-CM transplantation stimulated the mobilization of bone marrow (BM)-derived EPC compared to control (678.7+/-44.1 vs. 340.0+/-29.1 CD34(+)/CD45(-) cells/1x10(5) mononuclear cells, P<0.05) and their recruitment to the ischemic muscles (5.9+/-0.7 vs. 2.6+/-0.4 CD34(+) cells/HPF, P<0.001) 3 days after the last injection.

CONCLUSIONS/SIGNIFICANCE

Intramuscular injection of EPC-CM is as effective as cell transplantation for promoting tissue revascularization and functional recovery. Owing to the technical and practical limitations of cell therapy, cell free conditioned media may represent a potent alternative for therapeutic angiogenesis in ischemic cardiovascular diseases.

Cell-based therapy facilitates venous thrombus resolution

Endothelial progenitor cells (EPC) are involved in many healing processes in cardiovascular diseases and can be found in spontaneously resolving venous thrombi. The purpose of the present study was to investigate whether the therapeutic administration of EPC might enhance the resolution of venous thrombi. For this purpose, venous thrombosis was induced in the infrarenal inferior vena cava (IVC) in 28 athymic nude rats. Culture expanded EPC derived from human peripheral blood mononuclear cells were injected intravenously two and four days after thrombus induction. Recanalisation of the IVC and thrombus organisation were assessed by laser Doppler measurements of the blood flow and immunohistochemical detection of endothelialised luminal structures in the thrombus. EPC transplantation resulted in significantly enhanced thrombus neovascularisation (capillary density: 186.6 +/- 26.7/HPF vs. 78 +/- 12.3/HPF, p<0.01; area covered by capillaries: 8.9 +/- 1.7 microm(2) vs. 2.5 +/- 1.3 microm(2), p<0.01) and was accompanied by a substantial increase in intra-thrombus blood flow (perfusion ratio: 0.7 +/- 0.07 vs. 0.3 +/- 0.08, p<0.02). These results were paralleled by augmented macrophage recruitment into resolving thrombi in the animals treated with EPC (39.4 +/- 4.7/HPF vs. 11.6 +/- 1.9/HPF, p<0.01). Our data suggest that EPC transplantation might be of clinical value to facilitate venous thrombus resolution in cases where current therapeutic options have limited success.

Clinical predictors of prophylaxis use prior to the onset of acute venous thromboembolism in hospitalized patients SWIss Venous ThromboEmbolism Registry (SWIVTER)

BACKGROUND

We investigated clinical predictors of appropriate prophylaxis prior to the onset of venous thromboembolism (VTE).

METHODS

In 14 Swiss hospitals, 567 consecutive patients (306 medical, 261 surgical) with acute VTE and hospitalization < 30 days prior to the VTE event were enrolled.

RESULTS

Prophylaxis was used in 329 (58%) patients within 30 days prior to the VTE event. Among the medical patients, 146 (48%) received prophylaxis, and among the surgical patients, 183 (70%) received prophylaxis (P < 0.001). The indication for prophylaxis was present in 262 (86%) medical patients and in 217 (83%) surgical patients. Among the patients with an indication for prophylaxis, 135 (52%) of the medical patients and 165 (76%) of the surgical patients received prophylaxis (P < 0.001). Admission to the intensive care unit [odds ratio (OR) 3.28, 95% confidence interval (CI) 1.94-5.57], recent surgery (OR 2.28, 95% CI 1.51-3.44), bed rest > 3 days (OR 2.12, 95% CI 1.45-3.09), obesity (OR 2.01, 95% CI 1.03-3.90), prior deep vein thrombosis (OR 1.71, 95% CI 1.31-2.24) and prior pulmonary embolism (OR 1.54, 95% CI 1.05-2.26) were independent predictors of prophylaxis. In contrast, cancer (OR 1.06, 95% CI 0.89-1.25), age (OR 0.99, 95% CI 0.98-1.01), acute heart failure (OR 1.13, 95% CI 0.79-1.63) and acute respiratory failure (OR 1.19, 95% CI 0.89-1.59) were not predictive of prophylaxis.

CONCLUSIONS

Although an indication for prophylaxis was present in most patients who suffered acute VTE, almost half did not receive any form of prophylaxis. Future efforts should focus on the improvement of prophylaxis for hospitalized patients, particularly in patients with cancer, acute heart or respiratory failure, and in the elderly.

Impaired endothelial progenitor cell function predicts age-dependent carotid intimal thickening

OBJECTIVES

We investigated whether qualitative or quantitative alterations of the endothelial progenitor cell (EPC) pool predict age-related structural vessel wall changes.

BACKGROUND

We have previously shown that age-related endothelial dysfunction is accompanied by qualitative rather than quantitative changes of EPCs. Animal studies suggest that impaired EPC functions lead to accelerated arterial intimal thickening.

METHODS

Intima-media thickness (IMT) was measured in the common carotid artery in our previously published groups of younger (25 +/- 1 years, n = 20) and older (61 +/- 2 years, n = 20) healthy non-smoking volunteers without arterial hypertension, hypercholesterolemia, and diabetes mellitus. Endothelial progenitor cells (EPCs, KDR(+)/CD34(+) and KDR(+)/CD133(+)) were counted in peripheral blood using flow cytometry. In ex vivo expanded EPCs, the function was determined as chemotaxis to VEGF, proliferation, and survival.

RESULTS

We observed thicker IMT in older as compared to younger subjects (0.68 +/- 0.03 mm Vs. 0.48 +/- 0.02 mm, P < 0.001). Importantly, there were significant inverse univariate correlations between IMT, EPC chemotaxis, and survival (r = -0.466 P < 0.05; r = -0.463, P < 0.01). No correlation was observed with numbers of circulating EPCs. Multivariate regression analysis revealed that age, mean arterial pressure and migration of EPCs were independent predictors of IMT (R (2 )= 0.58).

CONCLUSION

Impaired EPC function may lead to accelerated vascular remodeling due to chronic impairment of endothelial maintenance.

Oxidized low density lipoprotein impairs endothelial progenitor cell function by downregulation of E-selectin and integrin alpha(v)beta5

BACKGROUND

Oxidized low density lipoprotein (oxLDL) has been shown to induce apoptosis and senescence of endothelial progenitor cells (EPC). In the present study, we hypothesized that even sub-apoptotic concentrations of oxLDL impair the angiogenic potential of EPC and investigated if this effect is mediated by affecting adhesion and incorporation.

METHODS

A co-culture system of human microvascular endothelial cells and EPC was used to study the effect of sub-apoptotic concentrations of native (nLDL) and oxLDL on cell-cell interaction. The expression and the functional role of angiogenic adhesion molecules and integrins was monitored by FACS and neutralizing assay, respectively.

RESULTS

We observed an inhibition of tube formation and impairment of EPC integration into the vascular network of mature endothelial cells by oxLDL. In contrast, nLDL did not affect angiogenic properties of EPC. Incubation of EPC with sub-apoptotic oxLDL concentrations significantly decreased E-selectin and integrin alpha(v)beta(5) expression (37.6% positive events vs. 71.5% and 24.3% vs. 49.9% compared to control culture media without oxLDL). Interestingly, expression of alpha(v)beta(3), VE-cadherin and CD31 remained unchanged. Blocking of E-selectin and integrin alpha(v)beta(5) by neutralizing antibody effectively inhibited adhesion of EPC to differentiated endothelial cells (56.5% and 41.9% of control; p<0.001).

CONCLUSION

In conclusion, oxidative alteration of LDL impairs angiogenic properties of EPC at sub-apoptotic levels by downregulation of E-selectin and integrin alpha(v)beta(5), both substantial mediators of EPC-endothelial cell interaction.

Gene and stem cell therapy in peripheral arterial occlusive disease

Abstract

Peripheral arterial occlusive disease (PAOD) is a manifestation of systemic atherosclerosis strongly associated with a high risk of cardiovascular morbidity and mortality. In a considerable proportion of patients with PAOD, revascularization either by endovascular means or by open surgery combined with best possible risk factor modification does not achieve limb salvage or relief of ischaemic rest pain. As a consequence, novel therapeutic strategies have been developed over the last two decades aiming to promote neovascularization and remodelling of collaterals. Gene and stem cell therapy are the main directions for clinical investigation concepts. For both, preclinical studies have shown promising results using a wide variety of genes encoding for growth factors and populations of adult stem cells, respectively. As a consequence, clinical trials have been performed applying gene and stem cell-based concepts. However, it has become apparent that a straightforward translation into humans is not possible. While several trials reported relief of symptoms and functional improvement, other trials did not confirm this early promise of efficacy. Ongoing clinical trials with an improved study design are needed to confirm the potential that gene and cell therapy may have and to prevent the gaps in our scientific knowledge that will jeopardize the establishment of angiogenic therapy as an additional medical treatment of PAOD. This review summarizes the experimental background and presents the current status of clinical applications and future perspectives of the therapeutic use of gene and cell therapy strategies for PAOD.

Estrogen-mediated endothelial progenitor cell biology and kinetics for physiological postnatal vasculogenesis

Estrogen has been demonstrated to promote therapeutic reendothelialization after vascular injury by bone marrow (BM)-derived endothelial progenitor cell (EPC) mobilization and phenotypic modulation. We investigated the primary hypothesis that estrogen regulates physiological postnatal vasculogenesis by modulating bioactivity of BM-derived EPCs through the estrogen receptor (ER), in cyclic hormonally regulated endometrial neovascularization. Cultured human EPCs from peripheral blood mononuclear cells (PB-MNCs) disclosed consistent gene expression of ER alpha as well as downregulated gene expressions of ER beta. Under the physiological concentrations of estrogen (17beta-estradiol, E2), proliferation and migration were stimulated, whereas apoptosis was inhibited on day 7 cultured EPCs. These estrogen-induced activities were blocked by the receptor antagonist, ICI182,780 (ICI). In BM transplanted (BMT) mice with ovariectomy (OVX) from transgenic mice overexpressing beta-galactosidase (lacZ) regulated by an endothelial specific Tie-2 promoter (Tie-2/lacZ/BM), the uterus demonstrated a significant increase in BM-derived EPCs (lacZ expressing cells) incorporated into neovasculatures detected by CD31 immunohistochemistry after E2 administration. The BM-derived EPCs that were incorporated into the uterus dominantly expressed ER alpha, rather than ER beta in BMT mice from BM of transgenic mice overexpressing EGFP regulated by Tie-2 promoter with OVX (Tie-2/EGFP/BMT/OVX) by ERs fluorescence immunohistochemistry. An in vitro assay for colony forming activity as well as flow cytometry for CD133, CD34, KDR, and VE-cadherin, using human PB-MNCs at 5 stages of the female menstrual-cycle (early-proliferative, pre-ovulatory, post-ovulatory, mid-luteal, late-luteal), revealed cycle-specific regulation of EPC kinetics. These findings demonstrate that physiological postnatal vasculogenesis involves cyclic, E2-regulated bioactivity of BM-derived EPCs, predominantly through the ER alpha.

Stenting of Common Iliac Vein Obstructions Combined with Regional Thrombolysis and Thrombectomy in Acute Deep Vein Thrombosis

OBJECTIVES

To evaluate the efficacy of stent placement after infrainguinal loco-regional thrombolysis and iliac thrombectomy (surgical TT) of acute deep vein thrombosis (DVT) in patients with May-Thurner-Syndrome.

MATERIAL AND METHODS

We retrospectively analysed a group of 11 patients (9 women) (mean age 34 years, range 16-64 years) with surgical TT and additional intra-operative stenting due to compression of the common iliac vein. Patients underwent venography to demonstrate outflow patency after surgical TT, and to identify any obstruction at the level of the left-sided common iliac vein ("Beckenvenen-Sporn"). Obstruction at the level of arterial crossing was treated using Wallstents placed via an introducer sheath from the inguinal access site. Stents were fully deployed using balloons adjusted to the size of vein. Patients were treated with oral anticoagulants for 6 months, and followed using duplex ultrasonography.

RESULTS

Technical success defined as complete vein patency and normal valve function was documented in all 11 patients. One patient needed early stent extension due to residual stenosis. At 6 months follow-up one patient (9%) had an asymptomatic occlusion of the stented common iliac vein. In all 11/11 (100%) patients the femoral segment was found to be patent, and in 1/11 (9%) there was mild reflux with few clinical symptoms of post-thrombotic syndrome. The calculated cumulative primary patency rate for venous iliac stents was 82%, and assisted patency rate was 91%, which remained unchanged over a mean follow-up of 22 months.

CONCLUSION

Combining surgical TT and stenting of common iliac vein obstructions in DVT is safe, effective, and results in a acceptable venous patency.

Endothelial progenitor cells: from bench to bedside

Strong evidence suggests that bone marrow-derived cells play a role in physiological and pathological blood vessel growth in the adult, both by augmenting angiogenesis through the secretion of angiogenic growth factors and by providing a rich source of progenitor cells that can differentiate into mature vascular endothelial cells. This is a true paradigm shift, since adult neovascularization processes were thought to be limited to angiogenesis. The cells that are critical to postnatal blood vessel growth – endothelial progenitor cells – may be analogous to the embryonic angioblast, in that they can circulate, proliferate and participate in the development of vascular networks by differentiating in situ, probably via the formation of cell clusters into mature endothelial cells. Therefore, initial reports have seen analogs to the process of vasculogenesis in the embryo, where the de novo synthesis of vessels occurs through the formation of blood island-like clusters, which subsequently connect and eventually form systemic vasculature. Recent work implicates precursors of endothelial cells in such processes as myocardial ischemia and infarction, limb ischemia, wound healing, atherosclerosis, endogenous endothelial repair and tumor vascularization. These new insights into the vascular biology of endothelial regeneration and repair led to the development of new cell therapeutic strategies to enhance adult neovascularization and re-endothelialization in ischemic cardiovascular diseases.

Nitric oxide differentially regulates proliferation and mobilization of endothelial progenitor cells but not of hematopoietic stem cells

To investigate the role of nitric oxide in controlling endothelial progenitor (EPC) and hematopoietic stem cell (HSC) mobilization, wild-type mice, L-NAME treated WT and eNOS-/- mice received either PBS or G-CSF for 5 days. Under unstimulated conditions bone marrow of either L-NAME treated WT and eNOS-/- mice, representing acute and chronic NO-deficiency, showed higher CD34(+)Flk-I+ EPC numbers compared to their WT littermates. Furthermore, CD34(+)Flk-I+ progenitors under NO-deficient conditions showed a higher cell turn over since the proliferation and apoptosis activity under in vivo as well as in vitro conditions were enhanced. In line with this finding bone marrow derived EPC differentiation towards endothelial cells was modulated in an NO-dependent manner. Administration of G-CSF resulted in an increase of EPC within the bone marrow of WT animals with a consecutive release of these cells into the peripheral circulation. Under NO-deficient conditions G-CSF failed to increase EPC numbers. In contrast, the HSC population c-kit(+)Lin- was not influenced by nitric oxide. Thus, NO differentially supports the mobilization of the endothelial committed progenitor subpopulation in bone marrow but does not have an effect on HSC in vivo.

Impaired progenitor cell activity in age-related endothelial dysfunction

OBJECTIVES

We investigated whether human age-related endothelial dysfunction is accompanied by quantitative and qualitative alterations of the endothelial progenitor cell (EPC) pool.

BACKGROUND

Circulating progenitor cells with an endothelial phenotype contribute to the regeneration and repair of the vessel wall. An association between the loss of endothelial integrity and EPC modification may provide a background to study the mechanistic nature of such age-related vascular changes.

METHODS

In 20 old and young healthy individuals (61 +/- 2 years and 25 +/- 1 year, respectively) without major cardiovascular risk factors, endothelial function, defined by flow-mediated dilation of the brachial artery via ultrasound, as well as the number and function of EPCs isolated from peripheral blood, were determined.

RESULTS

Older subjects had significantly impaired endothelium-dependent dilation of brachial artery (flow-mediated dilation [FMD] 5.2 +/- 0.5% vs. 7.1 +/- 0.6%; p < 0.05). Endothelium-independent dilation after glycerol trinitrate (GTN) was not different, but the FMD/GTN ratio was significantly lower in old subjects (49 +/- 4% vs. 37 +/- 3%; p < 0.05), suggesting endothelial dysfunction. There were no differences in the numbers of circulating EPCs, defined as CD34/KDR or CD133/KDR double-positive cells in peripheral blood. In contrast, lower survival (39 +/- 6 cells/mm(2) vs. 65 +/- 11 cells/mm(2); p < 0.05), migration (80 +/- 12 vs. 157 +/- 16 cells/mm(2); p < 0.01), and proliferation (0.20 +/- 0.04 cpm vs. 0.44 +/- 0.07 cpm; p < 0.05) implicate functional impairment of EPCs from old subjects. The FMD correlated univariately with EPC migration (r = 0.52, p < 0.05) and EPC proliferation (r = 0.49, p < 0.05). Multivariate analysis showed that both functional features represent independent predictors of endothelial function.

CONCLUSIONS

Maintenance of vascular homeostasis by EPCs may be attenuated with age based on functional deficits rather than depletion of CD34/KDR or CD133/KDR cells.

Paget-Schroëtter syndrome: what to do?

Paget-Schroëtter syndrome, or primary thrombotic occlusion of the axillary-subclavian vein, is diagnosed in a 42-year-old man subsequently treated with thrombolysis and anticoagulation. Treatment strategies, including early and delayed surgical options, are discussed to determine the best risk/benefit ratio.

Human endothelial progenitor cells from type II diabetics exhibit impaired proliferation, adhesion, and incorporation into vascular structures

BACKGROUND

The recent discovery of circulating endothelial progenitor cells (EPCs) has altered our understanding of new blood vessel growth such as occurs during collateral formation. Because diabetic complications occur in conditions in which EPC contributions have been demonstrated, EPC dysfunction may be important in their pathophysiology.

METHODS AND RESULTS

EPCs were isolated from human type II diabetics (n=20) and age-matched control subjects (n=20). Proliferation of diabetic EPCs relative to control subjects was decreased by 48% (P<0.01) and inversely correlated with patient levels of hemoglobin A1C (P<0.05). Diabetic EPCs had normal adhesion to fibronectin, collagen, and quiescent endothelial cells but a decreased adherence to human umbilical vein endothelial cells activated by tumor necrosis factor-alpha (TNF-alpha) (P<0.05). In a Matrigel assay, diabetic EPCs were 2.5 times less likely to participate in tubule formation compared with controls (P<0.05).

CONCLUSIONS

These findings suggest that type II diabetes may alter EPC biology in processes critical for new blood vessel growth and may identify a population at high risk for morbidity and mortality after vascular occlusive events.