Weakness of lower limb muscle in symptomatic peripheral artery disease with media sclerosis detected by ultrasound shear wave elastography.

Background: Symptomatic peripheral arterial disease (PAD) is difficult to non-invasively diagnose in the presence of calcified, media sclerotic arteries that are incompressible by blood pressure cuffs. Standard ankle-brachial index (ABI) measurements in these PAD patients are very often not helpful. Shear wave elastography (SWE) is a modern ultrasound technique to detect peripheral muscle stiffness changes i.e. muscle weakness during exercise. In a pilot study, we examined whether SWE could be a reproducible tool for diagnosing ischemic loss of muscle stiffness in patients with PAD and concomitant arterial media sclerosis. Patients and methods: N=13 consecutive patients with peripheral artery disease and media sclerosis were enrolled in the pilot study. All 13 patients were symptomatic in different stages of their PAD due to hemodynamically relevant arterial stenosis or occlusions of limb arteries as confirmed by oscillography, color-coded duplex sonography or angiography. Results: ABI measurements were invalid in all 13 patients. Mean SWE measurements of medial gastrocnemius muscles showed a significant transient muscle stiffness loss (weakness) at maximum exercise (active dorsal flexion of the foot, 103.4±25.9 kPa on the asymptomatic vs. 62.5±21.9 kPa on the symptomatic limb (p<0.001). Conclusions: SWE can reproducibly detect peripheral muscle weakness during exercise in the symptomatic leg of media sclerotic PAD patients. SWE of lower limb muscles may help to identify symptomatic PAD in patients presenting with invalid ABI measurements and unclear vascular status.

Bioresorbable zinc stent with ultra-thin center struts attenuates stent jail in porcine femoral artery bifurcations.

INTRODUCTION: An ultra-thin, fracture-resistant and bioresorbable stent may be advantageous for provisional stenting in vessel bifurcations, if catheter passage and side-branch post-dilatation is facilitated to prevent a 'stent jail' by struts obstructing the orifice of a major side branch. MATERIAL AND METHODS: We studied a highly radiopaque, slowly bioresorbable zinc alloy stent characterized by a novel design of a radiopaque-marked region of ultra-thin struts in the center of the stent. The stent is characterized by an extended range flexibility and high fracture resistance. Zn-stents and Zn-drug eluting stents (DES) were implanted opposite to rigid Nitinol stents into both femoral artery bifurcations of 21 juvenile pigs, followed for one and three months and studied by angiography and histomorphometry.Results and conclusion: Bare Zn-stents with thinner stent struts showed less neointimal hyperplasia compared to Zn-stents with thicker struts. Neointimal formation was further reduced by 12% in Zn-alloy DES. Both, bare Zn-stents and Zn-DES, can be precisely positioned into the femoral artery bifurcation, allowing easy balloon catheter passage through the very thin strut mesh. Side branch orifices remained open after Zn-stent deployment without stent jailing. No stent fractures or particles emboli occurred after the deployment. A Zn-stent with ultra-thin center struts may be useful for provisional stenting in vessel bifurcations.

Gender-related differences in patients undergoing transcatheter mitral valve interventions in clinical practice: 1-year results from the German TRAMI registry.

OBJECTIVES: Information on gender-related differences in terms of baseline characteristics and clinical outcome of patients undergoing MitraClip® implantation in daily clinical practice have been studied in smaller populations previously. This study sought to additionally evaluate gender-related differences in a larger German real-world patient population. METHODS AND RESULTS: We analyzed data from the prospective and multicenter German TRAMI Registry. Between 08/2010 and 07/2013 327 women and 501 men underwent MitraClip® implantation for significant mitral valve regurgitation. Female patients were significantly older and showed higher rates of frailty compared to men. In contrast, men had significantly higher rates of comorbidities compared to women. The majority of patients underwent MitraClip® implantation for secondary mitral regurgitation, with no significant gender-related differences. MitraClip® treatment was equally effective in terms of procedural results and residual mitral regurgitation in women and men and complication rates were low. However, in this real-world analysis severe bleeding complications were significantly higher in women (p = .02) and re-intervention rates were significantly higher in men after MitraClip® treatment (p = .02). Women showed less improvement in functional NYHA class after MitraClip® treatment compared to men at 1-year follow-up (FU; p < .001). No significant differences between female and male patients were found in 1-year mortality and in re-hospitalization rates. CONCLUSION: In this analysis from a large prospective, multicenter real-world registry MitraClip® implantation is safe and effective for treatment of significant mitral regurgitation with equal postprocedural results and mortality rates during 1-year follow-up. Men and women showed a persisting and significant clinical benefit at 1-year FU after treatment. Complication and re-intervention rates were low. Additional studies are needed to further evaluate our findings on increased bleeding complications and decreased functional improvement in women at 1-year follow-up after MitraClip® therapy.

Expression of the oxygen-sensitive transcription factor subunit HIF-1α in patients suffering from secondary Raynaud syndrome.

Anti-ischemic therapy remains a challenge due to the complexity of hypoxia response pathways. Hypoxia-inducible factor (HIF)-1 is a heterodimer transcription factor consisting of 2 subunits, HIF-1α and HIF-1ß. Hypoxia-dependent activation of HIF-1α regulates cellular O2 homeostasis. Raynaud syndrome (RS), as a comorbidity of the autoimmune disease systemic sclerosis (SS), is characterized by vasospasms that limit blood flow to the limbs, resulting in hypoxia. A single-center randomized study was conducted to compare prostaglandin E1 (PgE1) therapy with a treatment combining PgE1 and an endothelin-1 blocker, bosentan. A total of 30 patients suffering from SS with RS were enrolled. We examined the regulation of HIF-1α, its target heme oxygenase-1 (HMOX-1), and the serum levels of the HIF-1α protein in a subset of patients as well as in ten healthy individuals. The expression of HIF-1α and HMOX-1 in monocytes was measured using absolute plasmid-based quantitative real-time PCR, whereas serum HIF-1α levels were measured with ELISA. Samples were taken at the time of randomization and after 24 weeks. We found that HIF-1α and HMOX-1 mRNA expression in monocytes and serum HIF-1α protein levels were significantly higher in the SS/RS patients compared to the healthy control group. Single-drug therapy significantly increased HIF-1α and HMOX-1 mRNA expression in monocytes and serum HIF-1α protein levels in the SS/RS patients compared to those at the time of randomization, whereas combining PgE1 with an endothelin-1 blocker prevented the further increases in HIF-1α and HMOX-1 expression. We propose HIF-1α and HMOX-1 as novel markers for anti-ischemic therapy in RS.

Drug-coated balloons--the importance of packing and dosing antiproliferative drugs.

Several balloon catheters coated with paclitaxel have been shown to reduce restenosis rates in the superficial femoral artery (SFA) revealing a relatively wide therapeutic window of effective doses ranging from 2 to 3 µg/mm(2) balloon surface area. Delivering lower antiproliferative drug doses to the vessel wall may not be inferior to higher drug doses provided that effective drug-excipient formulations have been chosen. Leaving non-flow limiting dissection in the SFA non-stented might be an option after use of drug-coated balloons.

A novel hollow and perforated flexible wire allows the safe and effective local application of thrombolytic therapy in a mouse model of deep vein thrombosis.

We tested the feasibility of local thrombolytic therapy via a novel hollow flexible and perforated wire in a mouse model of deep vein thrombosis. Inferior vena cava (IVC) thrombosis was induced by vessel wall exposure to ferric chloride after laparotomy in anesthetized C57Bl/6 mice. Thrombus formation was visualized by intravital microscopy of rhodamine-labeled platelets and leukocytes. A nitinol hypotube coronary wire with perforated tip was inserted via a 0.8 × 40 mm canula into the IVC lumen distal to the site of ferric chloride exposure. Either tissue plasminogen activator (tPA, alteplase) or saline (control) was administered via the platinum wire distal to the thrombus, avoiding mechanical fragmentation. Thrombus size was assessed by immunohistochemistry (platelet CD41 staining). Intravital microscopy of the IVC demonstrated platelet-containing thrombus growth starting 1 min after ferric chloride exposure. Alteplase administration resulted in significant thrombus size reduction within 10-20 min observed by intravital microscopy and confirmed by histological assessment of IVC cross-sections. Saline-treated mice (n = 4) demonstrated near total IVC occlusion with thrombotic material (84 ± 8% of cross-sectional area in serial sections), whereas alteplase-treated mice showed a dose-dependent decrease of thrombotic area [56 ± 5% with 1.5, 39 ± 4 % with 15 and 21 ± 6% with 150 mg/kg, respectively (n = 4)]. We demonstrate that a flexible hollow and perforated wire enables the successful application of thrombolytic therapy to IVC thrombi in mice without vessel wall perforation. Flexible wire-based thrombolytic therapy appears to be a safe and reliable method for thrombus dissolution even in fragile small veins and may become a promising strategy for targeted therapy of small vessel thrombosis.

The Impact of COVID-19 on Mortality and Clinical Characteristics in Hospitalized Patients With Peripheral Artery Disease in the Year 2020 in Germany.

BACKGROUND: The COVID-19 pandemic developed its full destructive capacity in 2020. This retrospective study aimed to examine the effects of COVID-19 on the mortality and the clinical characteristics in PAD patients with COVID-19 compared to PAD patients without COVID-19. METHODS AND RESULTS: Data derived from a German nationwide register of the year 2020 which encompassed all hospitalized patients with PAD (n = 173.075); N = 2553 also suffered from a COVID-19 infection and had significantly higher mortality rates of 11.2%. PAD + COVID-19 patients presented more clinical complications like major amputations (11.59%), myocardial infarction (2.08%), cardiogenic shock (2.98%), chronic kidney failure with GFR<= 15 mL/min (5.33%) and prolonged ventilation time >48 h (3.37%). Rates of pulmonary thromboembolism (0.24%), myocardial infarction (2.08%), and stroke (1.02%) were low in patients with PAD + COVID-19. Adjusted regression analyses for risk differences revealed possible causes of higher mortality rates, such as prolonged ventilation time, pneumonia, major amputations, multiple organ system failure, and length of hospital stay in patients with severe PAD (Rutherford 5-6) + COVID-19. CONCLUSION: Pneumonia and major amputations were associated with high mortality rates in PAD + COVID-19 in 2020. However, we could not detect a relevant influence of pulmonary thromboembolism, myocardial infarction or stroke on higher death rates of PAD + COVID-19.

Treatment of functional mitral valve regurgitation with the permanent percutaneous transvenous mitral annuloplasty system: results of the multicenter international Percutaneous Transvenous Mitral Annuloplasty System to Reduce Mitral Valve Regurgitation in Patients with Heart Failure trial.

OBJECTIVES: PTOLEMY-2 was a prospective multicenter phase I single-arm feasibility trial to evaluate the second-generation permanent percutaneous transvenous mitral annuloplasty (PTMA) device in reducing functional mitral regurgitation (MR). BACKGROUND: Percutaneous MR reduction has been performed through a direct method of clipping and securing the mitral leaflets together or an indirect approach of reducing mitral annular dimension via the coronary sinus. The PTMA device is the only coronary sinus mitral repair device without a static fixation element. METHODS: Patients with at least moderate functional MR, New York Heart Association functional class II to IV, and left ventricular ejection fraction of 20% to 50% were enrolled at 14 centers in 5 countries. Device effects on patients were assessed by serial echocardiography, quality of life (QOL), and exercise capacity metrics. RESULTS: A total of 43 patients were recruited, and 30 patients (70%) were implanted with a permanent PTMA device with a mean follow-up of 5.8 ± 3.8 months. The primary safety end point (freedom from death, myocardial infarction, stroke, or emergency surgery) at 30 days was met in 28 patients, whereas 2 patients died of device-related complications. The primary efficacy end point (MR reduction of at least 1.0 grade or reduction of regurgitant orifice area by 0.1 cm(2) or regurgitant volume by 15 mL or regurgitant fraction by 10% compared with baseline) was obtained in 13 patients. No significant changes were noted in MR parameters, ventricular volumes, or QOL. Distance walked on 6 minutes testing at 6-month follow-up increased from 331 ± 167 m to 417 ± 132 m (P = .65). Compared with nonresponders, responders had a higher baseline regurgitant orifice area >0.2 cm(2) (P = .001) and less prior history of myocardial infarction (P = .02), coronary artery bypass surgery (P = .03), and ischemic MR (P = .04). CONCLUSIONS: Overall, PTMA had mild impact on MR reduction, left ventricular remodeling, QOL, and exercise capacity. During follow-up, the risk/benefit ratio remained suboptimal.

Muscle ultrasound shear wave elastography for detection of early onset lower limb ischemia in patients with veno-arterial extracorporeal membrane oxygenation.

BACKGROUND AND OBJECTIVES: Limb ischemia or compartment syndrome, requiring surgery, are some of the frequent cannula-related complications in patients supported with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). The purpose of this exploratory study is to depict and evaluate the dynamic changes in the lower limb muscles with ultrasound shear wave elastography as marker for early lower limb ischemia. METHODS: Eleven patients with VA-ECMO after cardiac arrest were included in this study. Seven patients received distal perfusion cannula (DPC) after implantation of the VA-ECMO, whereas 4 had no DPC after VA-ECMO. Compartment syndrome was clinically excluded in all patients. Both lower limbs, e.g., with and without arterial cannula, were monitored with near-infrared spectroscopy (NIRS) for the oxygen saturation of the local tissue. We performed ultrasound shear wave elastrography (SWE) to assess dynamic changes of the medial gastrocnemius muscle at maximum passive muscle stretch (exercise) of both legs. Color-coded duplexsonography was conducted to examine the blood flow velocity of the popliteal artery of the lower limb. RESULTS: We found no difference between DPC and no DPC (p = 0.115) during use of VA-ECMO. However, we detected marked lower limb muscle perfusion deficits of cannulated (58.9 ± 13.5 kPa) vs. cannula-free limb (95.7 ± 27.9 kPa: p < 0.001), applying SWE. No relationship was detected between NIRS measurements and SWE values (kPa) of both lower limbs. The mean peak systolic velocity of the popliteal artery at the cannulated side (30.0 ± 11.7 cm/s) was reduced compared to the non-cannulated side (39.3 ± 18.6 cm/s; p = 0.054). CONCLUSIONS: Regardless of DPC after implantation of VA-ECMO, the gastrocnemius muscles seem to lose function due to cannula-related microcirculatory deficits. Muscle function analysis via SWE combined with NIRS might offer a sensitive indicator for early onset leg ischemia during VA-ECMO-related arterial cannulation.

Transient hyperoxic reoxygenation reduces cytochrome C oxidase activity by increasing superoxide dismutase and nitric oxide.

Oxygen therapies have been shown to be cytoprotective in a dose-dependent fashion. Previously, we have characterized the protective effects of moderate hyperoxia on cell viability of ischemic human cardiomyocytes and their mitochondrial membrane potential by transient addition of oxygenated perfluorocarbons to the cell medium. Now, we report that the activity and expression of cytochrome c oxidase (COX) after prolonged ischemia depend on the amount of oxygen delivered during reoxygenation. Transient hyperoxia during reoxygenation results in a decrease of COX activity by 62 +/- 15% and COX expression by 67 +/- 5%, when hyperoxic tensions of approximately = 300 mm Hg are reached in the cell medium. This decrease in COX expression is prevented by the inhibition of inducible nitric-oxide synthase (iNOS). Immunoblot analysis of ischemic human cardiomyocytes revealed that hyperoxic reoxygenation causes a 2-fold increase of iNOS, leading to a rise in nitric oxide production by 140 +/- 45%. Hyperoxic reoxygenation is further responsible for a 2-fold activation of hydrogen peroxide production and an increase in cytosolic superoxide dismutase expression by 35 +/- 10%. NADPH availability has no effect on the hyperoxia-induced decrease of superoxide. Overall, these results indicate that transient hyperoxic reoxygenation in optimal concentrations increases the level of nitric oxide by activation of iNOS and superoxide dismutase, thereby inducing respiration arrest in mitochondria of ischemic cardiomyocytes.

Success of arterial revascularization determined by contrast ultrasound muscle perfusion imaging.

BACKGROUND: In the early postoperative evaluation of the success of arterial revascularization, ankle-brachial index (ABI) and other noninvasive tests lack reliability, especially in patients with incompressible arteries or local edema. Contrast-enhanced ultrasound (CEUS) imaging of limb muscle perfusion may be an alternative to standard tests if it detects treatment success reliably. METHODS: We compared a simplified CEUS method with clinical staging, pulse volume recording (PVR), and ABI in patients with lifestyle-limiting peripheral arterial disease undergoing revascularization by percutaneous transluminal angioplasty (PTA) or bypass surgery. Patients underwent staging, PVR, ABI, and CEUS before, directly after, and 3 to 5 months after successful PTA (n = 20) or successful bypass grafting (n = 14). For CEUS, contrast agent was injected into an antecubital vein, and the time from beginning to peak intensity of contrast enhancement (TTP) in the calf muscle was measured. RESULTS: Successful revascularization by both PTA and bypass was associated with a significant improvement in staging, PVR, ABI, and TTP directly after intervention and at follow-up. Median ABI increased from 0.60 to 0.85 (P = .001) after PTA and from 0.36 to 0.76 (P = .003) after bypass surgery. Median TTP decreased from 45 seconds to 24 seconds (P = .015) and from 30 seconds to 27 seconds (P = .041), respectively. McNemar analysis revealed unidirectional changes in both ABI and TTP (P = .625 after PTA and P = 1.000 after bypass surgery), and equivalence analysis showed 95% confidence intervals within clinical indifference, indicating that TTP was equivalent to standard tests in detecting successful revascularization. CONCLUSIONS: Contrast ultrasound perfusion imaging of calf muscle after arterial revascularization may be a valuable alternative to standard noninvasive tests such as ABI or PVR to determine the success of an arterial revascularization.

Treatment of coronary in-stent restenosis with a paclitaxel-coated balloon catheter.

BACKGROUND: Treatment of coronary in-stent restenosis is hampered by a high incidence of recurrent in-stent restenosis. We assessed the efficacy and safety of a paclitaxel-coated balloon in this setting. METHODS: We enrolled 52 patients with in-stent restenosis in a randomized, double-blind, multicenter trial to compare the effects of a balloon catheter coated with paclitaxel (3 microg per square millimeter of balloon surface area) with those of an uncoated balloon catheter in coronary angioplasty. The primary end point was late luminal loss as seen on angiography. Secondary end points included the rates of restenosis (a binary variable) and major adverse cardiac events. RESULTS: Multivessel disease was present in 80% of patients in both groups. Quantitative coronary angiography revealed no significant differences in baseline measures. At 6 months, angiography showed that the mean (+/-SD) in-segment late luminal loss was 0.74+/-0.86 mm in the uncoated-balloon group versus 0.03+/-0.48 mm in the coated-balloon group (P=0.002). A total of 10 of 23 patients (43%) in the uncoated-balloon group had restenosis, as compared with 1 of 22 patients (5%) in the coated-balloon group (P=0.002). At 12 months, the rate of major adverse cardiac events was 31% in the uncoated-balloon group and 4% in the coated-balloon group (P=0.01). This difference was primarily due to the need for target-lesion revascularization in six patients in the uncoated-balloon group (P=0.02). CONCLUSIONS: Treatment of coronary in-stent restenosis with paclitaxel-coated balloon catheters significantly reduced the incidence of restenosis. These data suggest that the inhibition of restenosis by local drug delivery may not require stent implantation and sustained drug release at the site of injury. (ClinicalTrials.gov number, NCT00106587 [ClinicalTrials.gov].).

Differences of platelet adhesion and thrombus activation on amorphous silicon carbide, magnesium alloy, stainless steel, and cobalt chromium stent surfaces.

BACKGROUND: Coronary stenting is considered to be the gold standard of percutaneous coronary interventions, because stents are able to reduce early and late elastic recoil (negative remodeling) and restenosis in comparison with balloon angioplasty alone. OBJECTIVE: It is known that stent thrombogenicity and neointimal formation are determined by the surface characteristics of the stent platform, electrochemical features of the stent surface, and the degree of degradation after implantation. Metallic stents coated with amorphous silicon carbide and biodegradable stents made of magnesium alloy have been introduced clinically, but there are no data available comparing the biocompatibility of these novel stent materials with conventional stents. METHODS: We demonstrate simple and reproducible in vitro methods assessing the rate of platelet adhesion and thrombus activation for biocompatibility tests of different stent surfaces. RESULTS: We show that amorphous silicon carbide and magnesium alloy stent surfaces markedly lower the rate of platelet adhesion and platelet/fibrin activation when compared with uncoated stainless steel or cobalt chromium alloy surfaces. Semiconductor materials on the stent surface reduce platelet and fibrin activation by increasing the critical electron gap to greater than 0.9 eV resulting in a lower electron transfer out of the stent material. CONCLUSION: Passive stent coatings with specific semiconducting properties such as amorphous silicon carbide or magnesium alloy reduce thrombogenicity and may improve biocompatibility of a stent platform.

Zn-alloy provides a novel platform for mechanically stable bioresorbable vascular stents.

Metallic Zn alloys have recently gained interest as potential candidates for developing platforms of bioresorbable vascular stents (BVS). Previous studies revealed that Mg alloys used for BVS can degrade too early, whereas PLLA materials may fail to provide effective scaffolding properties. Here we report on results of a new bioresorbable, metallic stent made from a Zn-Ag alloy studied in a porcine animal model of thrombosis and restenosis. While the tensile strength (MPa) of Zn-3Ag was higher than that of PLLA and resembled Mg's (WE43), fracture elongation (%) of Zn-3Ag was much greater (18-fold) than the PLLA's or Mg alloy's (WE43). Zn-3Ag exposed to HAoSMC culture medium for 30 days revealed degradation elements consisting of Zn, O, N, C, P, and Na at a 6 nm surface depth. Platelet adhesion rates and blood biocompatibility did not differ between Zn-3Ag, PLLA, Mg (WE43), and non-resorbable Nitinol (NiTi) stent materials. Balloon-expandable Zn-3Ag alloy BVS implanted into iliofemoral arteries of 15 juvenile domestic pigs were easily visible fluoroscopically at implantation, and their bioresorption was readily detectable via X-ray over time. Histologically, arteries with Zn-3Ag BVS were completely endothelialized, covered with neointima, and were patent at 1, 3, and 6 months follow-up with no signs of stent thrombosis. Zn-3Ag alloy appears to be a promising material platform for the fabrication of a new generation of bioresorbable vascular stents.

Publisher Correction: Real-time magnetic resonance imaging - guided coronary intervention in a porcine model.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Real-time magnetic resonance imaging - guided coronary intervention in a porcine model.

X-ray fluoroscopy is the gold standard for coronary diagnostics and intervention. Magnetic resonance imaging is a radiation-free alternative to x-ray with excellent soft tissue contrast in arbitrary slice orientation. Here, we assessed real-time MRI-guided coronary interventions from femoral access using newly designed MRI technologies. Six Goettingen minipigs were used to investigate coronary intervention using real-time MRI. Catheters were custom-designed and equipped with an active receive tip-coil to improve visibility and navigation capabilities. Using modified standard clinical 5 F catheters, intubation of the left coronary ostium was successful in all animals. For the purpose of MR-guided coronary interventions, a custom-designed 8 F catheter was used. In spite of the large catheter size, and therefore limited steerability, intubation of the left coronary ostium was successful in 3 of 6 animals within seconds. Thereafter, real-time guided implantation of a non-metallic vascular scaffold into coronary arteries was possible. This study demonstrates that real-time MRI-guided coronary catheterization and intervention via femoral access is possible without the use of any contrast agents or radiation, including placement of non-metallic vascular scaffolds into coronary arteries. Further development, especially in catheter and guidewire technology, will be required to drive forward routine MR-guided coronary interventions as an alternative to x-ray fluoroscopy.

Oxygenated perfluorochemicals improve cell survival during reoxygenation by pacifying mitochondrial activity.

Perfluorochemicals (PFCs) are known to provide a unique tool for controlled uptake and delivery of oxygen. We have characterized the effects of incremental oxygen delivery on cell viability of human ischemic cardiomyocytes using chemically inert PFCs as oxygen carrier. We have found that cell viability after prolonged ischemia depends on the dose of oxygen supplementation by oxygenated (ox) PFCs during reoxygenation. Although reoxygenation with the transient addition of oxPFCs in high concentrations (2250 microMO2 in 0.4 muM PFCs) results in decreased cell viability compared with normoxic reoxygenation, cell survival increases by 30 +/- 4% after reoxygenation with moderate oxPFC concentrations (750 muM O2 in 0.1 microM PFCs). Immunoblot analysis revealed that oxPFC-supplemented reoxygenation causes marked (16-fold) deactivation of death-associated protein kinase (DAPK) signaling an increase in mitochondrial membrane potential and a decreased steady-state level of superoxide by 19 +/- 3%. Reoxygenation with oxPFCs is further responsible for a 2-fold activation of AMP-activated protein kinase (AMPK) signaling an inadequate ATP supply by oxidative phosphorylation during reoxygenation. Addition of oxPFCs stabilizes both hypoxia-inducible factor (HIF) 1-alpha and 2-alpha during reoxygenation. Overall, these results indicate that moderate doses of oxPFCs can improve cell survival during reoxygenation, causing deactivation of DAPK, up-regulation of AMPK, and HIF1-alpha and 2-alpha stabilization. These effects of oxPFCs are dose-dependent, and they lead to a stabilization of the mitochondrial membrane potential, decreased steady-state levels of superoxide, and pacification of mitochondrial activity.

Shear Wave Elastography of Peripheral Muscle Weakness in Patients with Chronic Congestive Heart Failure.

Forty-five study participants (28 chronic heart failure [CHF] patients and 17 control participants) were prospectively enrolled in this study to investigate the clinical potential of ultrasound shear wave elastography (SWE) in identifying peripheral muscle weaknesses in chronic heart failure patients. Muscle stiffness in the gastrocnemius muscle during extension (stretch) and the lower arm flexor muscles during flexion was assessed via shear wave elastography, measuring the shear modulus (kPa) for the resting and contractile states in a range of 0-300 kPa. Resting kPa revealed no significant difference between CHF and CP, but exercise kPa for extension and flexion was significantly lower in CHF than CP. The area under the receiver operating characteristic curve of the denominator kPa-Exercise stretch was 0.916, associated with a sensitivity of 89%, a specificity of 71% and a corresponding cutoff value of 81.1 kPa. Shear wave elastography is thus a reproducible and sensitive ultrasound method for evaluating peripheral muscle deficits in patients with CHF.

Systemic application of anti-ICAM-1 monoclonal antibodies to prevent restenosis in rabbits: an anti-inflammatory strategy.

OBJECTIVES: After vascular intervention, cell adhesion molecules such as ICAM-1 and VCAM are fundamental in inflammatory processes. In particular, ICAM-1 expression is strongly associated with macrophage-rich areas in restenotic lesions. Therefore, we hypothesized an anti-restenotic effect by systemic application of anti-ICAM-1 monoclonal antibodies (mAb). METHODS: Thirty two rabbits underwent balloon angioplasty and stent implantation either in the right or left iliac artery, Animals received either anti-ICAM mAb or saline solution as a control. Animals were sacrificed 7 (n=8) and 14 (n=8) days and tissue was analyzed for basic fibroblast growth factor (bFGF) and transforming growth factor beta (TGF-beta) expression. Sixteen animals were sacrificed 6 months following treatment and tissue was harvested for histomorphometric analysis. RESULTS: After balloon injury, bFGF significantly increased from 7 to 14 days only in the control group and was significantly higher compared to the anti-ICAM group. At 14 days after stent implantation, controls showed a significant increase of both bFGF and TGF-beta, whereas the anti-ICAM group only showed a significant increase of TGF-beta. Histomorphometric analysis for neointimal growth did not show any differences between control and anti-ICAM groups either after balloon injury or after stent implantation at 6 months. CONCLUSION: Administration of anti-ICAM-1 mAb following either balloon angioplasty or stent implantation results in a suppression of bFGF in the early phase of restenosis, whereas TGF-beta significantly increases from 7 to 14 days after stent implantation independent of anti-ICAM-1 mAb application. Therefore we conclude that anti-inflammatory strategies are able to interfere with growth factor expression after vascular injury.