Capillaroscopic differences between primary Raynaud phenomenon and healthy controls indicate potential microangiopathic involvement in benign vasospasms.

BACKGROUND: For primary Raynaud phenomenon (PRP), an otherwise unexplained vasospastic disposition is assumed. To test the hypothesis of an additional involvement of distinct ultrastructural microvascular alterations, we compared the nailfold capillary pattern of patients with PRP and healthy controls. METHODS: A total of 120 patients with PRP (with a median duration of vasospastic symptoms of 60 [IQR: 3-120] months) were compared against 125 controls. In both groups, nailfold capillaroscopy was performed to record the presence of dilatations, capillary edema, tortuous capillaries, ramifications, hemorrhages, and reduced capillary density and to determine a semiquantitative rating score. Further, the capacity of finger skin rewarming was investigated by performing infrared thermography in combination with cold provocation. RESULTS: Unspecific morphologic alterations were found in both, PRP, such as controls, whereby the risk for PRP was four times as high in the presence of capillary dilations (CI: 2.3-7.6) and five times as high if capillary density was reduced (CI: 1.9-13.5). Capillary density correlated with thermoregulatory capacity in both hands in the PRP group, but not in controls. In addition, a negative correlation between the microangiopathy score and the percentage degree of rewarming in both hands was found for patients with PRP only. CONCLUSION: We found specific differences within the microvascular architecture between patients with PRP and controls. As a conclusion, PRP may not be an entirely benign vasospastic phenomenon, but might be associated with subtle microcirculatory vasculopathy. In addition, we suggest that the implementation of a scoring system might serve as guidance in the diagnostic process at least of patients with long-standing PRP.

Comparison Evaluation of Automated Nucleated Red Blood Cell Enumeration by Sysmex XN 1000 in Comparison With Microscopic Reference in Children Under 1 Year.

BACKGROUND: In newborns, elevated nucleated red blood cell (NRBC) levels can be associated with enhanced erythropoietic stress and might be predictive for adverse outcome. Also, the presence of NRBC in peripheral blood might lead to erroneous enumeration results of white blood cells in automated hematology analyzers. We aimed to assess the comparability of the Sysmex XN 1000 to manual slide reviews and correlation of NRBC with inflammation markers. METHODS: Specimens of 3397 children under 1 year were compared by automated and microscopic NRBC enumeration. Additionally, potential correlations between NRBC and age and inflammation markers were examined. RESULTS: Overall, there was good correlation (r = 0.97) between automated (range: 0%-3883%) and microscopic enumeration (range: 0%-3694%) of NRBC with high comparability up to a NRBC value of 200% and an increase in the variation between the two methods with increasing NRBC numbers. When 94 samples with ≤ 200% NRBC and ≥ 30% divergence between methods were separately reanalyzed with respect to overlapping cell populations in their scattergrams, Sysmex would have generated unrecognized incorrect automated results in 47 samples, corresponding to 1.4% of total study samples. NRBC counts were negatively correlated to age, but not to inflammation markers. CONCLUSION: Sysmex XN 1000 is highly precise in the enumeration of NRBC in children under 1 year up to counts of 200% and might replace time-intense manual counting in routine diagnostics. In the setting of neonatal and intensive care diagnostics, microscopic control and supervision of scattergrams are highly recommended for any automated NRBC enumeration processes.

Assessing the influence of diurnal variations and selective Xa inhibition on whole blood aggregometry.

A biological rhythm in platelet function is well known. Multiple electrode aggregometry (MEA) is a widely used assay to measure platelet aggregability. Rivaroxaban is a new oral anticoagulant frequently used in an increasing number of indications. In this randomized, crossover trial we investigated whether a biological rhythm exists in MEA measurements and potential effects of rivaroxaban on platelet aggregation. Sixteen healthy volunteers were included in the study and blood samples were obtained at 08:00, 12:00, 16:00 and 20:00 h. Each subject was tested without rivaroxaban intake first and randomly assigned to 3 days of rivaroxaban intake at 08:00 or 3 days of rivaroxaban intake at 20:00 h and vice versa. In MEA measurements, a significant increase in platelet aggregation after addition of ristocetin at 12:00 h compared to other investigated time-points (122 ± 8 AU at 12:00 h vs. 109 ± 9 AU at 08:00 h, 114 ± 10 AU at 16:00 h and 103 ± 8 AU at 20:00 h, p = 0.027) could be detected. There was no biological rhythm detectable using other agonists (ADP, arachidonic acid, thrombin-receptor activating peptide-6). After rivaroxaban intake at 08:00 h an increased ristocetin-induced platelet aggregation was measured in the next morning (126 ± 4 AU (rivaroxaban at 08:00 h) vs. 109 ± 9 AU (no rivaroxaban), 111 ± 6 AU (rivaroxaban at 20:00 h; p = 0.002). No other effects of rivaroxaban on platelet function were found. We detected a biological rhythm in ristocetin-induced platelet aggregation with a peak at 12:00 h (noon). No influence of selective Xa inhibition on platelet aggregation was detected.

Influence of proton pump inhibitors and VKORC1 mutations on CYP2C9-mediated dose requirements of vitamin K antagonist therapy: a pilot study.

Interindividual variations in dose requirements of oral vitamin K antagonists (VKA) are attributed to several factors, including genetic variant alleles of vitamin K epoxide reductase complex subunit 1 (VKORC1) and cytochrome P450 2C9 (CYP2C9), but also interaction with co-medications. In this context, proton pump inhibitor (PPI)-related alterations of VKA maintenance dose requirements have been published. The present investigation aimed to test for an interaction profile of oral VKA-therapy and PPIs in relation to the CYP2C9 genotype. Median weekly stable VKA dose requirements over 1 year were recorded in 69 patients. Patients were genotyped for CYP2C9*2, CYP2C9*3, VKORC1c.-1639G>A and VKORC1c.174-136C>T and assessed for an association with PPI use and total VKA maintenance dose requirements. PPI users with CYP2C9 genetic variations required significantly lower weekly VKA maintenance doses than those with the wild-type genotype (t-test: P = 0·02). In contrast, in subjects without PPI use, the CYP2C9 genotype had no significant influence on oral VKA dose requirements. Further, the combined CYP2C9/VKORC1 genotype was a significant predictor for VKA dose requirements [linear regression: estimate: -1·47, standard error: 0·58 (P = 0·01)]. In conclusion, in carriers of CYP2C9 gene variations, the interference with the VKA metabolism is modified by PPI co-medication and the VCKORC1 genotype. Preceding knowledge of the genetic profile and the awareness for potentially occurring severe over-anticoagulation problems under PPI co-medication could contribute to a safer and personalized VKA pharmacotherapy.

Predictors of participation in preventive health examinations in Austria.

BACKGROUND: Preventive health check-ups in Austria are offered free of charge to all insured adults (98% of the population) and focus on early detection of chronic diseases, primary prevention, and health counseling. The study aims to explore predictors of compliance with the recommended interval of preventive health check-up performance. METHODS: Source of data was the Austrian Health Interview Survey 2006/07 (15,474 subjects). Participation in a preventive health examination during the last three years was used as dependent variable. Socio-demographic and health-related characteristics were used as independent variables in a multivariate logistic regression analysis. RESULTS: Results show that 41.6% of men and 41.8% of women had attended a preventive health check-up within the last three years. In multivariate analysis, subjects ≥ 40 years, with higher education, higher income or born in Austria were significantly more likely to attend a preventive health check-up. Furthermore, a chronic disease was associated with a higher attendance rate (OR: 1.21; CI: 1.07-1.36 in men; OR: 1.19; CI: 1.06-1.33 in women). CONCLUSIONS: Attendance rates for health check-ups in the general Austrian population are comparatively high but not equally distributed among subgroups. Health check-ups must increase among people at a young age, with a lower socio-economic status, migration background and in good health.

Long COVID symptoms in hospital employees after post-vaccination SARS-CoV-2 infection in Austria: A study on self-reported incidence and associated factors.

PURPOSE: Post acute sequelae of SARS-CoV-2 infection are defined by persistence or re-occurrence of symptoms six to 12 weeks after SARS-CoV-2 infections. METHODS: Twice vaccinated hospital employees after mild to moderate post-vaccination SARS-CoV-2 infection completed a questionnaire on the incidence of general, respiratory, neuropsychiatric, dermatological and gastrointestinal symptoms, experienced during their acute infection and eight weeks after recovery. Post acute sequelae of SARS-CoV-2 infection were analysed in relation to socio-demographic-, health-, virus- and acute infection-related characteristics. RESULTS: 73 participants, 25 women and 48 men with a mean age of 40.9 years, with a post-vaccination SARS-CoV-2 infection completed the survey. Out of these 93 % reported at least one symptom at time of initial SARS-CoV-2 infection, 31.5 %, predominantly women, reported post acute sequelae at least eight weeks after the acute infection stage. Fatigue, dysgeusia and dysosmia, headache or difficulty concentrating and shortness of breath during acute infection, BMI> 25 and pre-existing pulmonary disorders were associated with post acute sequelae of SARS-CoV-2 infection. Participants with initially more than five symptoms were four times more likely to report post acute sequelae. CONCLUSION: It is suggested that the multiplicity of symptoms during acute SARS-CoV-2 infections increases the risk for post acute symptoms.

Temporal association between COVID-19 vaccination and Raynaud's phenomenon: A case series.

COVID-19 vaccine-related adverse events are mostly minor to moderate, and serious events are rare. Single cases of Raynaud's phenomenon (RP) in temporal proximity to COVID-19 vaccination have been reported. Demographic data, medical history, and detailed information regarding vaccination status and RP characteristics were obtained from patients with confirmed RP after COVID-19 vaccination. Fifteen participants reported the initial manifestation of RP, which occurred in 40% after the first, in 33% after the second, and in 27% after the third vaccination. RP development and occurrence of episodes were not linked to any specific vaccine type. New onset of disease was observed in 40% of the vaccinees after BNT162b2, in 33% after mRNA-1273, and in 27% after ChAdOx1 vaccination. Three out of four participants with preexisting RP prior to COVID-19 vaccination reported aggravation in frequency and intensity after immunization. Although COVID-19 vaccination is pivotal in controlling the pandemic, the observed temporal association between vaccine administration and RP occurrence warrants global activities to support pharmacovigilance for the detection of adverse reactions, one of which may include RP.

Modeling the protective effect of previous compulsory smallpox vaccination against human monkeypox infection: from hypothesis to a worst-case scenario.

OBJECTIVES: Human monkeypox (MPX) cases are escalating worldwide. Smallpox vaccination, which was compulsory in Austria until 1981, was reported to confer 85% cross-protection against MPX. METHODS: To assess the impact of smallpox vaccine-induced protection, the age-dependent vaccine-induced immunity against human MPX and the probability of infection according to age in the general population of Vienna, Austria, were determined using a modified susceptible-infected-removed model. RESULTS: Within the population born before 1981, the average vaccine-induced protective effect was calculated at 50.4%, whereas in the population born thereafter, protection was lacking. The overall probability of infection after exposure to an infected patient was calculated at 73.8%, which exceeds the threshold value of 46.9% for an index patient to infect at least one other person (R ≥1.0). CONCLUSION: Our model shows that if no additional interventions are taken, the collective immunization status of the population alone will not suffice to contain human MPX. Although the majority of cases have occurred in a subpopulation, given the steadily increasing incidence, dissemination into the general population remains possible, as observed before with HIV. Our model emphasizes the need for adequate containment measures and may aid in specific risk assessment because it can easily be adapted to other populations and cohorts worldwide.

Postvaccination infections among staff of a tertiary care hospital after vaccination with severe acute respiratory syndrome coronavirus 2 vector and mRNA-based vaccines.

OBJECTIVES: The identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen or RNA in respiratory specimens ≥14 days after administration of all recommended doses of authorized coronavirus disease 2019 (COVID-19) vaccines is defined as breakthrough infection. In the present investigation, mRNA and vector-based SARS-CoV-2 vaccines were analysed with respect to postvaccination infections in vaccinated hospital employees. METHODS: A total of 8553 staff members were vaccinated with BNT162b2 (47%) or ChAdOx1-S (53%) between January and May 2021. In a retrospective observational cohort study, incidence of SARS-CoV-2 postvaccination infections was analysed in relation to demographic data, viral load, virus variants, vaccine brand and vaccination status at time of positive PCR test (fully vaccinated: ≥14 days since second dose; partially vaccinated: >21 days since first, but <14 days after second dose; insufficiently vaccinated: <22 days since first dose). RESULTS: Within the follow-up period, ending on 31 July 2021, person-time at risk-adjusted monthly rates for SARS-CoV-2 postvaccination infections were 0.18% (BNT162b2) and 0.57% (ChAdOx1-S) for insufficiently vaccinated, 0.34% (BNT162b2) and 0.32% (ChAdOx1-S) for partially vaccinated and 0.06% (BNT162b2) and 0.04% (ChAdOx1-S) for fully vaccinated participants. The two vaccine types did not differ with respect to hazard ratios for any of the respective postvaccination infection types. No cases of COVID-19-related hospitalizations or deaths were reported. Genotyping of positive PCR specimens revealed 42 variants of concern: B.1.1.7 (Alpha variant; n = 34); B.1.351 (Beta variant; n = 2), B.1.617.2 (Delta variant; n = 6). CONCLUSIONS: BNT162b2 and ChAdOx1-S are both effective in preventing breakthrough infections; however, it seems important, that all recommended vaccine doses are administered.

Effectiveness and cost-efficacy of phosphate binders in hemodialysis.

OBJECTIVES: Worldwide, incidence rates of chronic renal insufficiency have clearly increased over the past decade, especially in people of older age. Hyperphosphatemia is the strongest independent risk factor for mortality in renal patients. In order to reduce serum phosphate concentrations to recommended values, phosphate binders (P binders) are used to bind ingested phosphate in the digestive tract. Besides the traditional therapies with calcium and aluminium salts, sevelamer and lanthanum represent recent developments on the market. The purpose of the present health technology assessment (HTA) report was to compare the effectiveness and safety of different P binders in patients with chronic renal insufficiency. METHODS: Based on a systematic literature search followed by a two-part selection process with predefined criteria 18 publications were included in the assessment. RESULTS: All P binders effectively controlled serum phosphate, calcium and parathyroid hormone concentrations. The numbers of hypercalcemic episodes were higher when using calcium-containing P binders compared to sevelamer and lanthanum. Regarding mortality rate, cardiovascular calcification and bone metabolism no definite conclusions could be drawn; however, sevelamer seemed to be more effective than calcium in certain patient subgroups, such as older patients and patients with preexisting arterial calcification. CONCLUSIONS: From a medical point of view, sevelamer showed superiority over calcium-containing P binders at least for special indications.

Comparison of metabolic and biomechanic responses to active vs. passive warm-up procedures before physical exercise.

Active warm-up before physical exercise is a widely accepted practice to enhance physical performance, whereas data on modalities to passively raise tissue temperature are rare. The study compared the effect of active vs. passive warm-up procedures before exercise on energy supply and muscle strength performance. Twenty young, male volunteers performed 3 spiroergometer-test series without prior warm-up and after either an active or passive warm-up procedure. Oxygen uptake (VO2), heart rate (HR), pH value, and lactate were determined at 80% of individual VO2max values and during recovery. Comparing no prior warm-up with passive warm-up, pH values were lower at the fourth test minute (p < 0.004), and lactate values were higher at the sixth and third minutes of recovery (p < 0.01 and p < 0.010, respectively), after no prior warm-up. Comparing active with passive warm-up, HR was lower, and VO2 values were higher at the fourth and sixth test minutes (p < 0.033 and p < 0.011, respectively, and p < 0.015 and p < 0.022, respectively) after active warm-up. Differentiation between active and passive warm-up was more pronounced than between either warm-up or no warm-up. Conditions that may promote improved performance were more present after active vs. passive warm-up. Thus, athletes may reach the metabolic steady state faster after active warm-up.

"Oldest old" patients in intensive care: prognosis and therapeutic activity.

OBJECTIVE: In view of ethical considerations and the limited resources in intensive care medicine, the present investigation aims to give a descriptive overview of the prognosis and therapeutic activity for the oldest age group of elderly patients admitted to an intensive care unit (ICU) in comparison with younger ICU patients. PATIENTS AND METHODS: 3069 patients admitted to the ICU during a seven-year period were categorized into four age groups: under 65 years (48%), 65 to 74 years (26%), 75 to 85 years (22%) and 85 years or older (5%). Type and reason for ICU admission, length of ICU stay, severity of illness as measured by the simplified acute physiology score (SAPS)-II, level of provided care as measured by the simplified therapeutic intervention scoring system (TISS)-28, and vital status at the date of ICU discharge were recorded. RESULTS: The ICU mortality rate of patients aged 85 years or older was significantly higher than in patients under 65 (OR of mortality: 1.8, p < 0.001). Non-survivors had higher SAPS II levels (even when excluding age points) in all age groups, but higher daily average TISS points only in patients under 85. The daily average TISS score was negatively correlated to age (r = -0.03; p < 0.001) and was significantly lower in the oldest group when compared with all the younger groups (p < 0.001). The oldest patients had a significantly shorter length of stay (median: 2; interquartile range [IQR] 1-3, p < 0.001) than the younger patient groups. CONCLUSIONS: Within the very elderly population, age is an important and independent predictor of mortality, but acute severity of illness is even more strongly associated with mortality. Consequently, age alone may be an inappropriate criterion for allocation of ICU resources.

Deregulated BCL-2 family proteins impact on repair of DNA double-strand breaks and are targets to overcome radioresistance in lung cancer.

PURPOSE: DNA damage-induced cell death is a major effector mechanism of radiotherapy. Aberrant expression of anti-apoptotic BCL-2 family proteins is frequently observed in lung cancers. Against this background, we studied radioresistance mediated by BCL-2 family proteins at the mechanistic level and its potential as target for radiochemotherapy. METHODS: Lung cancer models stably expressing BCL-xL or MCL-1 were irradiated to study cell death, clonogenic survival, and DNA repair kinetics in vitro, and growth suppression of established tumors in vivo. Additionally, endogenous BCL-xL and MCL-1 were targeted by shRNA or pharmacologic agents prior to irradiation. RESULTS: Radiation exposure induced apoptosis at negligible levels. Yet, anti-apoptotic BCL-xL and MCL-1 expression conferred short-term and long-term radioresistance in vitro and in vivo. Radioresistance correlated with pertubations in homologous recombination repair and repair of DNA double-strand breaks by error-prone, alternative end-joining. Notably, genetic or pharmacologic targeting of BCL-xL or MCL-1 effectively sensitized lung cancer cells to radiotherapy. CONCLUSIONS: In addition to directly suppressing apoptosis, BCL-2 family proteins confer long-term survival benefits to irradiated cancer cells associated with utilization of error-prone repair pathways. Targeting BCL-xL and MCL-1 is an attractive strategy for improving lung cancer radiotherapy.

Plasminogen activator inhibitor-1 4G/5G genotype and residual venous occlusion following acute unprovoked deep vein thrombosis of the lower limb: A prospective cohort study.

BACKGROUND: A recent study suggested that the plasminogen activator inhibitor (PAI)-1 4G/5G genotype may play a role in the resolution of deep vein thrombosis (DVT) after surgery. In the present study, we investigated the association between PAI-1 4G/5G genotype and the persistence of venous occlusion after acute idiopathic DVT of the lower limb. METHODS: The PAI-1 4G/5G genotype was determined by real-Time PCR in 43 patients with unprovoked DVT of the lower limb. Residual venous occlusion was assessed by duplex sonography 1, 3, 6, 12 and 24months after the acute event. The PAI-1 Activity was determined by ELISA. RESULTS: Ten patients (23%) were homozygous for 4G (4G/4G), 27 patients (63%) were heterozygous 4G/5G and 6 patients (14%) were homozygous for 5G (5G/5G). Residual venous occlusion (RVO) was found in 77%, 65%, 58%, 56% and 37% of the overall study population, at 1, 3, 6, 12 and 24months after acute DVT, respectively. The presence of residual venous occlusion at 1, 3, 6, 12 and 24months after acute unprovoked DVT did not differ significantly between genotypes, but age was associated with RVO. Plasma levels of PAI-1 activity correlated with body mass index but was not associated with genotypes in our study. CONCLUSION: The PAI-1 4G/5G genotype was not a relevant predictor of persistent residual venous occlusion after idiopathic DVT, which however was associated with age.

Molecular dissection of effector mechanisms of RAS-mediated resistance to anti-EGFR antibody therapy.

Monoclonal antibodies targeting the epidermal growth factor receptor (EGFR), cetuximab and panitumumab, are a mainstay of metastatic colorectal cancer (mCRC) treatment. However, a significant number of patients suffer from primary or acquired resistance. RAS mutations are negative predictors of clinical efficacy of anti-EGFR antibodies in patients with mCRC. Oncogenic RAS activates the MAPK and PI3K/AKT pathways, which are considered the main effectors of resistance. However, the relative impact of these pathways in RAS-mutant CRC is less defined. A better mechanistic understanding of RAS-mediated resistance may guide development of rational intervention strategies. To this end we developed cancer models for functional dissection of resistance to anti-EGFR therapy in vitro and in vivo. To selectively activate MAPK- or AKT-signaling we expressed conditionally activatable RAF-1 and AKT in cancer cells. We found that either pathway independently protected sensitive cancer models against anti-EGFR antibody treatment in vitro and in vivo. RAF-1- and AKT-mediated resistance was associated with increased expression of anti-apoptotic BCL-2 proteins. Biomarkers of MAPK and PI3K/AKT pathway activation correlated with inferior outcome in a cohort of mCRC patients receiving cetuximab-based therapy. Dual pharmacologic inhibition of PI3K and MEK successfully sensitized primary resistant CRC models to anti-EGFR therapy. In conclusion, combined targeting of MAPK and PI3K/AKT signaling, but not single pathways, may be required to enhance the efficacy of anti-EGFR antibody therapy in patients with RAS-mutated CRC as well as in RAS wild type tumors with clinical resistance.

Endurance training reduces circulating inflammatory markers in persons at risk of coronary events: impact on plaque stabilization?

Inflammatory pathways are involved in destabilization of atherosclerotic plaques. We assessed the hypothesis that endurance training decreases circulating concentrations of inflammatory markers in persons with coronary artery disease (CAD) and cardiovascular risk factors (CVRFs). Thirty-two subjects with CAD and/or CVRFs joined a 12-week supervised endurance training. We found a significant decrease of the chemokines interleukin (IL)-8 (pre: 3.9+/-0.6, change: -1.2+/-0.4 pg/ml, -21%, p=0.002) and monocyte chemoattractant protein-1 (pre: 213+/-9, change: -20.4+/-8.2 pg/ml, -5%, p=0.03). Diabetes mellitus (DM) significantly influenced changes of IL-8 (p=0.002). IL-8 substantially dropped by 39% in diabetics. Moreover, matrix metalloproteinase-9 (MMP-9) highly significantly decreased in response to training (pre: 750+/-98, change: -278+/-77 ng/ml, -18%, p=0.005). Exercise-induced changes of MMP-9 were influenced by concomitant use of statins (p=0.038). We observed a particularly strong MMP-9 reduction of 44% in patients treated with statins. Acute phase reactants IL-6 (pre: 1.7+/-0.3, change: +0.25+/-0.7 pg/ml, +4%, p=0.58) and high sensitivity C-reactive protein (pre: 2.1+/-0.5, change: -0.25+/-0.4 mg/l, -9%, p=0.54) did not change in response to training. In conclusion, endurance training decreased circulating chemokines and MMP-9, which may in part explain its beneficial effect on coronary risk. Patients with DM or treated with statins because of hypercholesterolemia may particularly take advantage.

Association of a functional polymorphism in the clopidogrel target receptor gene, P2Y12, and the risk for ischemic cerebrovascular events in patients with peripheral artery disease.

BACKGROUND AND PURPOSE: There is considerable variability in the antiplatelet effects of the thienopyridine agent "clopidogrel." We tested for an association of gene sequence variations in P2Y12 and occurrence of neurological adverse events in patients with symptomatic peripheral artery disease (PAD) during clopidogrel treatment. METHODS: We studied 137 patients undergoing antiplatelet therapy with clopidogrel and 336 patients with aspirin for the occurrence of neurological events (ischemic stroke and/or carotid revascularization). Prevalence of 2 previously described exonic polymorphisms of the P2Y12 gene, 34C>T and 52G>T, was determined by polymerase chain reaction. RESULTS: Genotype frequencies for mutated, heterozygous, and wild-type alleles for the 34C>T and the 52G>T polymorphisms were 9% (n=40), 44% (n=210), and 47% (n=223), and 4% (n=17), 27% (n=127), and 70% (n=329), respectively. During the median follow-up of 21 months, neurological events occurred in 8% of patients. In patients with aspirin therapy, neither polymorphism was associated with neurological events. However, in clopidogrel patients, carriers of at least one 34T allele had a 4.02-fold increased adjusted risk for neurological events compared with carriers of only 34C alleles (95% confidence interval, 1.08 to 14.9). Neither polymorphism was associated with all-cause mortality. CONCLUSIONS: In PAD patients, clopidogrel response variability exists, which may result in increased risk for cerebrovascular events. Sequence alterations of the target receptor gene represent one possible mechanism for clopidogrel failure. Whether identification of the 34C>T polymorphism as a contributor to this process could serve as risk stratification tool, an indicator for higher clopidogrel doses, or the use of alternate agents warrants further investigation.

Homocyst(e)ine-lowering therapy does not affect plasma asymmetrical dimethylarginine concentrations in patients with peripheral artery disease.

BACKGROUND: Elevated plasma asymmetrical dimethylarginine (ADMA) is suggested to contribute to hyperhomocyst(e)ine-related vascular dysfunction in patients with peripheral artery disease (PAD). The present trial investigated whether homocyst(e)ine (Hcy)-lowering therapy with vitamin-B (vit-B) and folic acid affects plasma concentrations of ADMA in patients with PAD and hyperhomocyst(e)inemia. SUBJECTS AND METHODS: Forty-nine subjects (15 women, 34 men) with PAD and fasting plasma total Hcy concentrations greater than 15 micromol/liter were randomized to receive either oral vit-B and folic acid therapy (n = 27) or placebo (n = 22) for 6 wk. Fasting venous blood samples were monitored for plasma total Hcy, vit-B12 and folate, ADMA, symmetric dimethylarginine, L-arginine, and high-sensitivity C-reactive protein. RESULTS: After 6 wk, plasma Hcy concentrations were decreased, and concentrations of vit-B12 and folate were elevated in patients with vitamin supplementation (all P < 0.05 vs. baseline) and unchanged in the placebo group. Dimethylarginine plasma concentrations were not affected by treatment. High-sensitivity C-reactive protein correlated with ADMA plasma concentrations (r = 0.29; P < 0.01). CONCLUSION: The lack of vit-B and folic acid therapy on plasma concentrations of ADMA renders a role of extracellular methylarginines unlikely to be involved in the pathophysiology of hyperhomocyst(e)inemia and its complications.

Osteoprotegerin plasma concentrations correlate with severity of peripheral artery disease.

OBJECTIVE: Osteoprotegerin (OPG), a member of the tumor necrosis factor receptor family, is involved in the process of bone turnover and also in the pathogenesis of osteoporosis and premature calcification of the vascular system. In the present study on patients with peripheral artery disease (PAD), we correlated plasma OPG concentrations with severity of disease and the presence of cardiovascular risk factors. PATIENTS AND METHODS: Sixty-seven consecutive inpatients (26 females; mean age 70 years (S.D.: 12), undergoing percutaneous transluminal angioplasty (PTA) because of advanced symptomatic PAD of the lower extremities were studied. Severity grade of disease (clinical stage after "Fontaine", functional measurements in terms of the ankle brachial index (ABI) and "Bollinger score" of angiographies), biochemical parameters and a detailed cardiovascular risk profile were documented. Fasting plasma concentrations of OPG were measured by a commercial sandwich enzyme immunoassay. MAIN RESULTS: The mean plasma concentrations of OPG were 5.3 pmol/l (S.D.: 3.3). Plasma OPG concentrations in subjects with PAD, clinical stages III-IV (n=15) were 7.9 pmol/l (S.D.: 5.3) and were significantly higher than in patients without ischemic ulcerations (n=52; 4.6 pmol/l; S.D.: 2.0; p<0.01). The mean value of Bollinger score was 29.1 (S.D.: 19.8). OPG was positively correlated with Bollinger score of disease (r=0.31; p<0.02), age (r=0.58; p<0.01) and creatinine-values (r=0.32; p<0.01) and negatively correlated with ABI (r=-0.39; p<0.03). CONCLUSION: In patients with PAD, plasma OPG concentrations were significantly higher in subjects with ischemic ulcerations than in those without and were positively correlated with higher severity grade of disease, age and creatinine-values. Further studies are required to analyze the role of OPG as a diagnostic marker for severity of atherosclerotic disease and to assess a possible therapeutic potential as "vasculoprotegerin".

Endurance training increases the number of endothelial progenitor cells in patients with cardiovascular risk and coronary artery disease.

OBJECTIVE: As regular physical exercise improves endothelial dysfunction and promotes cardiovascular health, we investigated the effect of training on angiogenesis by measuring the number of circulating endothelial progenitor cells (EPC), the level of EPC-mobilizing growth factors and tested vascular function by flow-mediated dilation (FMD) in patients with coronary artery disease (CAD) and cardiovascular risk factors (CVRF). In addition, degradation products of the NO pathway (NOx) were determined. METHODS AND RESULTS: Twenty patients with documented CAD and/or CVRF joined a 12-week supervised running training. Circulating EPCs--defined by the surface markers CD34, KDR and CD133--were measured at baseline and after exercise training by flow cytometry. We found a significant increase in circulating EPCs (2.9+/-0.4-fold increase; P < .0001), which was positively correlated with both, the change of FMD (r = .81, P < .001) and the increase of NOx synthesis (r = .83, P < .001). Plasma VEGF and erythropoietin did not change in response to exercise. However, we observed a positive correlation between the number of EPCs and erythropoietin at baseline (r = .70, P < .01) and after training (r = .73, P < .01). CONCLUSIONS: Regular exercise training augments the number of circulating EPCs in patients with CVRF and CAD and is associated with improved vascular function and NO synthesis.