Evaluation of the cost of atrial fibrillation during emergency hospitalization.

OBJECTIVE: The number of hospitalizations for atrial fibrillation has increased dramatically. This increase, in the number of hospital stays will continue, given the growth projections based on epidemiological data, and will contribute to significantly increase expenses for the social security system.The objective of this study was to evaluate the length of hospital stay, the average cost borne by social security, and the types of hospital stay expenditures for patients admitted through the emergency department for atrial fibrillation. METHODS: Patients were identified by using the minimal clinical summaries of seven general hospitals in Belgium in 2008. Only hospitalized patients having as primary diagnosis code ICD-9-CM 42731 'atrial fibrillation'were selected for this study. Hospital billing files were analysed in order to isolate the costs borne by social security. Outliers were isolated in order not to have results influenced by patients having an atypical length of stay. RESULTS: Results show that the mean length of stay was 8.6 days and the mean cost charged to social security was euro 3,066.02 per hospital stay.The mean cost of care was strongly associated with the degree of severity index related to the APR-DRG. Approximately 85% of the total cost was related to the cost of hospital days and medical procedures with medical imaging and laboratory tests being the two main cost inductors. 18% of patients had cardioversion during their hospital stay, including 4% who had only that treatment. 19% of patients used amiodarone. Flecainide and propafenone were also used, but less frequently. CONCLUSIONS: The mean cost of care for AF patients admitted via the emergency department is strongly associated with the degree of severity. Approximately 85% of the total cost is related to the cost of hospital days and medical procedures. Hypertension is the most common secondary diagnosis. An optimal treatment of this risk factor could help to reduce the risk of atrial fibrillation, and thereby reduce the morbidity and costs associated with this disease.

New Platform for Label-Free, Proximal Cellular Pharmacodynamic Assays: Identification of Glutaminase Inhibitors Using Infrared Matrix-Assisted Laser Desorption Electrospray Ionization Mass Spectrometry.

Cellular pharmacodynamic assays are crucial aspects of lead optimization programs in drug discovery. These assays are sometimes difficult to develop, oftentimes distal from the target and frequently low throughput, which necessitates their incorporation in the drug discovery funnel later than desired. The earlier direct pharmacodynamic modulation of a target can be established, the fewer resources are wasted on compounds that are acting via an off-target mechanism. Mass spectrometry is a versatile tool that is often used for direct, proximal cellular pharmacodynamic assay analysis, but liquid chromatography-mass spectrometry methods are low throughput and are unable to fully support structure-activity relationship efforts in early medicinal chemistry programs. Infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) is an ambient ionization method amenable to high-throughput cellular assays, capable of diverse analyte detection, ambient and rapid laser sampling processes, and low cross-contamination. Here, we demonstrate the capability of IR-MALDESI for the detection of diverse analytes directly from cells and report the development of a high-throughput, label-free, proximal cellular pharmacodynamic assay using IR-MALDESI for the discovery of glutaminase inhibitors and a biochemical assay for hit confirmation. We demonstrate the throughput with a ∼100,000-compound cellular screen. Hits from the screening were confirmed by retesting in dose-response with mass spectrometry-based cellular and biochemical assays. A similar workflow can be applied to other targets with minimal modifications, which will speed up the discovery of cell active lead series and minimize wasted chemistry resources on off-target mechanisms.

Vitamin D deficiency-induced hypertension is associated with vascular oxidative stress and altered heart gene expression.

Vitamin D deficiency (VDD) is associated with an increased cardiovascular risk. We investigated the effect of VDD on the cardiovascular system of growing male rats fed with a vitamin D-deficient diet. Using isolated rat aorta, we assessed both superoxide anion and endothelial-dependent relaxations. Microarray technology was used to identify changes induced by VDD in cardiac gene expression. Compared with control, VDD increased systolic blood pressure (P < 0.05) and superoxide anion production in the aortic wall (P < 0.05) and tended to increase serum levels of angiotensin II and atrial natriuretic peptide (P < 0.15). However, VDD slightly improved maximal relaxation to acetylcholine from 75 % ± 3% to 83% ± 2% (P < 0.05). Incubation of aortic rings either with nitro-l-arginine methyl ester (l-NAME) or catalase did not eliminate the enhancement of endothelial-mediated relaxation observed in vitamin D-deficient rats. Only incubation with indometacin or calcium-activated potassium channels blockers suppressed this difference. Compared with control, the expression of 51 genes showed different expression, including several genes involved in the regulation of oxidative stress and myocardial hypertrophy. In conclusion, VDD in early life increases arterial blood pressure, promotes vascular oxidative stress, and induces changes in cardiac gene expression. However, the endothelial-mediated regulation of vasomotor tone is maintained throughout the enhancement of an NO-independent compensatory pathway.

Impact of fibrinolysis on immediate prognosis of patients with out-of-hospital cardiac arrest.

Fibrinolytic therapy (FT) during out-of-hospital cardiac arrest (OHCA) has been studied in several trials, but they have produced unsatisfactory results even in the most recent Thrombolysis in Cardiac Arrest (TROICA) study. This study aimed to assess the impact of FT provided by an out-of-hospital emergency physician on the immediate prognosis of patients with OHCA. We performed a retrospective study in which the primary endpoint was survival to hospital admission. Among 5,102 patients with OHCA in Paris and the suburban area who received medical care from the Fire Brigade of Paris, 1,261 met the following inclusion criteria: age above 18 years with non-traumatic OHCA. Among 107 patients who received FT, 51 (47.7%) survived to hospital admission whereas 272 out of 1,154 (23.6%) patients who did not receive FT survived to hospital admission. A matching process based on a propensity score used to equalise potential prognosis factors in both groups demonstrated that FT was associated with more frequent survival to hospital admission (OR adjusted: 1.7; CI 95% [1.09-2.68]). This result was observed particularly in patients who were not initially shocked by automatic electrical defibrillator (AED) (OR(a) = 3.61; CI 95% [1.88-6.96]). This study showed that fibrinolysis was associated with improved survival to hospital admission, after performing a propensity analysis. FT may be beneficial in out-of-hospital arrest patients. However, any conclusions drawn are limited by the retrospective nature of the study.

Starting a medical home: better health at lower cost.

At Adventist HealthCare, a patient-centered medical home pilot project: Helped improve the health of high-risk members while increasing the efficiency of healthcare delivery. Supported the primary care physicians treating the high-risk patients. Reduced the costs of treating the patients.

Oxidative stress produced by circulating microparticles in on-pump but not in off-pump coronary surgery.

OBJECTIVE: This study was undertaken to assess whether plasmas isolated during off-pump coronary surgery trigger less oxidative stress than those isolated during on-pump surgery. METHODS AND RESULTS: Plasmas were sampled from patients before (TO), just after (TI) and 24 hours after (T2) cardiac surgery (n=24 on-pump and n=10 off-pump). Rings of rat thoracic aortas were incubated for 20 hours with these different plasmas (100 microl + 4 ml medium) or saline (control). Thereafter, superoxide anion production was assessed by chemiluminescence and the mean signal was expressed as percent of that in the control ring. In rat aorta exposed to plasmas from on-pump CABG patients (n=6), the signal was enhanced by 210 +/- 29% at T1 (P < 0.05) and by 174 +/- 29% at T2 (P < 0.05) versus 53 +/- 12% at T0. Moreover, at T1 and T2, there was an upregulation of p22(phox), the key subunit of NADPH oxidase, the main enzyme involved in oxidative stress of the vascular wall. In contrast, off-pump plasmas did not induce this superoxide production. Incubation with microparticles obtained by ultracentrifugation also markedly enhanced the signal at T1 and T2 (vs. T0) in the on-pump group (but not in the off-pump group). Selective removal of CD34, CD105, CD59, CD146, CD42 microparticles using flow cytometry did not abolish the signal. CRP and SAA plasma levels were enhanced only at T2 in both groups. CONCLUSIONS: Plasmas isolated after on-pump but not off-pump coronary bypass surgery can induce superoxide generation by the vascular wall which seems related to circulating microparticles remaining present at least 24 hours after the procedure that might be of endothelial origin.

Deficit in Central Auditory Processing as a Biomarker of Pre-Clinical Alzheimer's Disease.

Prevention of dementia due to Alzheimer's disease (d/AD) requires interventions that slow the disease process prior to symptom onset. To develop such interventions, one needs metrics that assess pre-symptomatic disease progression. Familiar measures of progression include cerebrospinal fluid (CSF) biochemical and imaging analyses, as well as cognitive testing. Changes in the latter can sometimes be difficult to distinguish from effects of "normal" aging. A different approach involves testing of "central auditory processing" (CAP), which enables comprehension of auditory stimuli amidst a distracting background (e.g., conversation in a noisy bar or restaurant). Such comprehension is often impaired in d/AD. Similarly, effortful or diminished auditory comprehension is sometimes reported by cognitively healthy elders, raising the possibility that CAP deficit may be a marker of pre-symptomatic AD. In 187 cognitively and physically healthy members of the aging, AD family history-positive PREVENT-AD cohort, we therefore evaluated whether CAP deficits were associated with known markers of AD neurodegeneration. Such markers included CSF tau concentrations and magnetic resonance imaging volumetric and cortical thickness measures in key AD-related regions. Adjusting for age, sex, education, pure-tone hearing, and APOEɛ4 status, we observed a persistent relationship between CAP scores and CSF tau levels, entorhinal and hippocampal cortex volumes, cortical thickness, and deficits in cognition (Repeatable Battery for Assessment of Neuropsychological Status total score, and several of its index scales). These cross-sectional observations suggest that CAP may serve as a novel metric for pre-symptomatic AD pathogenesis. They are therefore being followed up longitudinally with larger samples.

Rosuvastatin treatment protects against nitrate-induced oxidative stress in eNOS knockout mice: implication of the NAD(P)H oxidase pathway.

Nitrate tolerance is associated with an enhanced superoxide anion (O(2)(-)) production and may be attenuated by statins as they interact with the two main endothelial NO synthase (eNOS) and NAD(P)H oxidase pathways involved in this oxidative stress. Groups of wild-type (wt, C57Bl/6J) and eNOS knock-out mice (eNOS(-/-)) received rosuvastatin (20 mg kg(-1) day(-1) p.o.) for 5 weeks and a cotreatment with the statin plus nitroglycerin (NTG; 30 mg kg(-1) day(-1), subcutaneous injections b.i.d.) for the last 4 days. Another group received only NTG (30 mg kg(-1) d(-1), b.i.d. for 4 days) and finally control mice from both strains received no treatment. Rings of thoracic aortas from these groups were studied in organ baths. Relaxations to NTG (0.1 nM-0.1 mM) were determined on thromboxane analogue (U44619)-precontracted rings and O(2)(-) production (RLU 5 s(-1) mg(-1) of total protein content) was assessed in aorta homogenates with the lucigenin-enhanced chemiluminescence technique. Reverse transcriptase-polymerase chain reaction analysis was performed on aortas from both mice strains. In vivo NTG treatment induced a significant rightward shift of the concentration-effect curve to NTG compared to control group. There was, however, no cross-tolerance with non-nitrate sources of NO (unaltered response to acetylcholine in wt group). The rosuvastatin + NTG cotreatment was able to protect against the development of nitrate tolerance in both mice strains and L-mevalonate abolished this protective effect of rosuvastatin. In vivo treatment with apocynin, a purported NAD(P)H oxidase inhibitor, also produced a similar protection to that observed with rosuvastatin in both strains. Superoxide anion formation was increased after NTG treatment in both mice strains and the rosuvastatin + NTG cotreatment was able to reduce that production. Moreover, rosuvastatin treatment abolished the increase in gp91phox mRNA (an endothelial membrane NAD(P)H oxidase subunit) expression induced by in vivo exposure to NTG. These findings suggest that long-term rosuvastatin treatment protects against nitrate tolerance by counteracting NTG-induced increase in O(2)(-) production, probably via a direct interaction with the NAD(P)H oxidase pathway.

Protection of aortic endothelial function in both normal and diabetic rats by intravenous bolus injection of a medium-chain triglyceride: fish oil emulsion.

The bolus intravenous injection of a novel medium-chain triglyceride:fish oil emulsion (MCT:FO) was recently proposed as a tool to provoke a rapid and sustained increase of cell phospholipid content in long-chain polyunsaturated omega3 fatty acids, for instance in selected subjects prior to anesthesia and surgery. In this study, therefore, the possible protective effect of MCT:FO upon aortic endothelial function was investigated in both normal and diabetic rats. The animals were injected intravenously 20 h before sacrifice with 1.0 ml of either saline, MCT:FO or a control medium-chain triglyceride:long-chain triglyceride emulsion. The vasomotor response of isolated aortic rings was then explored by assessing the relaxation provoked by increasing concentrations of acetylcholine in rings contracted with phenylephrine. Such measurements were performed before and after exposure of the aortic rings to suitable concentrations of oxidized LDL. In both normal and diabetic rats, the prior injection of the MCT:FO emulsion protected the aortic rings against the deleterious effect of oxidized LDL. In the diabetic rats, a beneficial effect of the MCT:FO emulsion was even observed prior to exposure of the aortic rings to oxidized LDL. These findings support the view that this novel procedure is indeed appropriate to protect endothelial function against oxidative stress.

Sustained enrichment of liver phospholipids and triglycerides in eicosapentaenoate after a bolus intravenous injection of a medium-chain triglycerides:fish oil emulsion to streptozotocin (Type 1) and Goto-Kakizaki (Type 2) diabetic rats.

This study deals with the sustained enrichment of liver phospholipids and triglycerides in long-chain polyunsaturated omega3 fatty acids (omega3) found after the bolus intravenous injection of a novel medium-chain triglyceride:fish oil emulsion (MCT:FO) to streptozotocin (Type 1) and Goto-Kakizaki (Type 2) diabetic rats. Twenty hours after injection of the MCT:FO emulsion, the relative concentration of omega3 was indeed higher in liver phospholipids and triglycerides than that found in rats injected with either saline or a control medium-chain triglyceride:long-chain triglyceride emulsion. This coincided with a decrease in the ponderal percentage of C18:3omega3, C20:4omega6 and/or C22:4omega6 in liver triglycerides. The present study further documents differences between streptozotocin-induced and Goto-Kakizaki diabetic rats in terms of body weight, glycemia, liver triglyceride content and the fatty acid pattern of both liver phospholipids and triglycerides, as well as a close correlation in the latter animals between liver and plasma phospholipids or triglycerides as far as the ratio in the relative concentration of selected fatty acids representative of desaturase and elongase activities is concerned. In light of these and previous findings, it is proposed that the beneficial metabolic and functional events of the MCT:FO emulsion may display not solely a rapid but also sustained time course.

Preparation of poly(N-isopropylacrylamide) copolymers and preliminary assessment of their acute and subacute toxicity in mice.

A subacute toxicity study was conducted to evaluate the oral toxicity profile of poly(N-isopropylacrylamide) (PNIPAAm) derivatives. These thermoresponsive polymers may have several potential pharmaceutical applications such as ingredient for oral solid dosage form. A preliminary acute oral toxicity study was performed with one of the polymer (PNIPAAm-co-NVA) at a unique dose of 4000 mg/kg body weight administered to six male and six female mice, to determine the dosage for further evaluation. No treatment-related effect was observed on behavior and health condition of the experimental animals during the 14 days observational period. The autopsy of the treated animals did not revealed any macroscopic changes in major organ aspects. Based on these preliminary results we selected a 2000 mg/kg body weight/day dose for the 28 days long subacute study. Three polymers were tested, namely PNIPAAm, PNIPAAm-co-NVA and PNIPAAm-co-AAc and compared to a saline control. No significant changes in clinical signs, body weight and food consumption, hematology, clinical chemistry or absolute organ weight were observed. Histological examination of excised major organs showed no marked differences between treated and control mice. In conclusion, PNIPAAm-co-NVA is well tolerated up to 4000 mg/kg body weight when administered orally. In addition, the subacute study indicated the absence of cumulative toxicity and a no-observed-adverse-effect level (NOAEL) of 2000 mg/kg was identified for PNIPAAm and its two copolymers. Further studies are mandatory.

Acute effects of passive smoking on peripheral vascular function.

Environmental tobacco smoke (ETS) acutely affects peripheral and coronary vascular tone. Whether ETS exerts specific deleterious effects on aortic wave reflection through nicotine exposure, whether they persist after ETS cessation, and whether the smoke environment impairs microvascular function and increases asymmetrical dimethyl-arginine levels are not known. We tested these hypotheses in a randomized, crossover study design in 11 healthy male nonsmokers. The effects of 1 hour of exposure to ETS, as compared with a nontobacco smoke and normal air, on augmentation index corrected for heart rate and skin microvascular hyperemia to local heating were examined. Augmentation index increased both during (P=0.01) and after (P<0.01) the ETS session but remained unchanged in the nontobacco smoke session when compared with normal air. Nicotine levels after the exposure were related to the peak rise in augmentation index (r=0.84; P<0.01), denoting a predominant role of nicotine in ETS vascular effects. This was confirmed in a second set of experiments (n=14), where the sublingual administration of nicotine was associated with an acute impairment in wave reflection as compared with placebo (P=0.001). Both ETS and nontobacco smokes increased plasma asymmetrical dimethyl-arginine levels (P<0.001), but only ETS reduced the late rise in skin blood flow in response to heating (P=0.03). In conclusion, passive smoking specifically increases aortic wave reflection through a nicotine-dependent pathway and impairs microvascular function, even after the end of the exposure. However, both tobacco and nontobacco passive smoking inhalation increase plasma asymmetrical dimethyl-arginine levels.

Rosuvastatin treatment protects against nitrate-induced oxidative stress.

Nitrate tolerance is associated with an enhanced superoxide anion production and can be attenuated by statins, which interact with the 2 main [eNOS and NAD(P)H oxidase] pathways involved in producing this oxidative stress. Three groups of normocholesterolemic rats were treated: group 1 received rosuvastatin (10 mg/kg/d PO) for 5 weeks and in the last 3 days cotreatment with nitroglycerin (NTG 50 mg/kg/d, subcutaneous injections BID); group 2 received only NTG (50 mg/kg/d BID for the last 3 days); and group 3 served as control. Rings of thoracic aortas from these groups were studied in organ baths. Relaxations to NTG (0.1 nM to 0.1 mM) were determined on phenylephrine-preconstricted rings and O2 production (RLU/10 s/mg dry weight) was assessed by lucigenin and the luminol analogue (L-012) chemiluminescence technique. In group 2 (NTG), the concentration-response curves to NTG were significantly shifted to the right: the pD2 (-log NTG concentration evoking a half-maximal relaxation) was 6.75+/-0.06 (n=7) versus 7.75+/-0.07 (n=7) in group 3 (not exposed to NTG, P<0.05); O2 production was enhanced (10,060+/-1,205, n=7 versus 5,235+/-1,052, n=7; P<0.05). In contrast, in group 1, the rightward shift was attenuated: pD2 value was 7.20+/-0.10 (n=8), P<0.05 versus group 2; O2 production was decreased (5911+/-663; n=9, P<0.05 versus group 2). In addition, before NTG exposure, rosuvastatin treatment decreased p22phox [the essential NAD(P)H oxidase subunit] abundance in the aortic wall and decreased NAD(P)H oxidase activity. In contrast, this treatment did not alter either eNOS abundance or the basal release of endothelium-derived NO. Interestingly, in vivo treatment with apocynin, an NAD(P)H oxidase inhibitor, produced a protection similar to that with rosuvastatin. Long-term rosuvastatin treatment protects against nitrate tolerance in the rat aorta by counteracting NTG-induced increase in O2 production. This protection seems to involve a direct interaction with the NAD(P)H oxidase pathway rather than an up-regulation of the eNOS pathway.

Prevention of nitrate tolerance by long-term treatment with statins.

UNLABELLED: Recent studies have shown that statins seem to upregulate the endothelial NO synthase pathway (eNOS) and may, therefore, enhance NO availability, a direct scavenger of O2- and an inhibitor of oxidative enzymes. METHODS: To assess whether the oxidative stress produced by an in vivo exposure to nitroglycerin (NTG) is attenuated by statins, 4 groups of normocholesterolemic rats were treated; group 1 received pravastatin (20 mg/kg/d p.o) and group 2 atorvastatin (10 mg/kg/d) both for 5 weeks and the last 3 days, a cotreatment with the statin plus NTG (50 mg/kg/d, s.c. injections b.i.d.); group 3 (NTG) received only NTG (50 mg/kg/d, b.i.d. for 3 days) and group 4 served as control. Rings of thoracic aortas from these groups were studied in organ baths. Relaxations to NTG (0.1 nM to 0.1 mM) were determined on phenylephrine-preconstricted rings and O2- production (counts/10 s/mg) was assessed by lucigenin chemiluminescence technique. RESULTS: In vivo NTG exposure induced a rightward shift of the concentration-response curves to NTG: the pD2 (-log NTG concentration evoking a half maximal relaxation) was 5.8 +/- 0.3 (n=7) vs. 7.2 +/- 0.2 in the control group (not exposed to NTG, n=7) and O2- production was enhanced (1259 +/- 71 vs. 787 +/- 76, (n=5) P<.05). In contrast, groups 1 (n=7) and 2 (n=7) behaved as the control group (pD2 values were 7.4 +/- 0.1 (n=7) and 6.9 +/- 0.1 (n=7); O2- production was 721 +/- 109 and 647 +/- 121). The protective effect on nitrate tolerance disappeared when L-NAME (an eNOS inhibitor, 100 mg/kg/d) was co-administered with NTG in groups 1 and 2. Incubation of aortic rings with NAD(P)H (100 microM) also impaired the protective effect of both statins. Moreover, before NTG exposure, aortic cGMP content, reflecting EDNO availability, was significantly enhanced in group 1 (P<.05 vs. control). CONCLUSION: Long-term statin treatment protects against nitrate tolerance by counteracting NTG-induced increase in O2- production. Both eNOS pathway and NAD(P)H oxidases seem to be involved in this protective mechanism.

Chronic hydroxymethylglutaryl coenzyme a reductase inhibition and endothelial function of the normocholesterolemic rat: comparison with angiotensin-converting enzyme inhibition.

Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors seem to have clinical benefits beyond those predicted by their lipid-lowering action. The objective was to evaluate the vascular effect of long-term treatment with statins on isolated rat aorta and their ability to prevent the acute toxicity of oxidized low-density lipoproteins (oxLDLs) compared with angiotensin-converting enzyme (ACE) inhibitors. Four groups of Wistar rats were treated for 5 weeks. Group 1 received pravastatin 20 mg/kg/d orally; group 2 received atorvastatin 10 mg/kg/d; group 3 received ciprofibrate 25 mg/kg/d; and group 4 served as control. Total cholesterol and triglyceride plasma levels were not altered, except in group 3, in which both parameters were decreased. The inhibitory effect of the endothelium on serotonin-induced contractions was significantly increased in group 1. A significant leftward shift of the concentration-response curves to acetylcholine (1 nM-0.1 mM) was observed in group 1 but the maximal relaxation to acetylcholine was similar in the four groups. In contrast, in the presence of human Cu2+-oxLDL (300 microg/ml, 30 min of preincubation), the maximal relaxation to acetylcholine was markedly decreased (p < 0.02) in groups 3 and 4 versus that of groups 1 and 2. No difference in superoxide accumulation was observed by the chemiluminescence technique. Cyclic guanosine monophosphate (cGMP), measured by enzyme immunoassay in aortic tissues, was increased in group 1 in the presence of superoxide dismutase. Endothelial nitric oxide synthase (eNOS) expression was not altered (Western blot and enzyme-linked immunosorbent assay). In aortas isolated from a fifth group of rats treated with an ACE inhibitor (ramipril 10 mg/kg/d for 6 weeks), similar results to those of group 1 were observed except that the eNOS abundance was significantly enhanced. Thus, long-term statin treatment upregulates the eNOS pathway and attenuates the acute toxicity of human oxLDL. In contrast to chronic ACE inhibition, the eNOS abundance is not increased.