bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotonin Increases Interleukin-6 Synthesis in Human Vascular Smooth Muscle Cells
Authors: Ito Takayuki , Ikeda Uichi , Shimpo Masahisa , Yamamoto Keiji , Shimada Kazuyuki
Published: June 2012

Background
—Interleukin-6 (IL-6) is a key molecule in chronic inflammation and has been implicated in the progression of atherosclerosis. Serotonin (5-hydroxytryptamine; 5-HT) causes vascular contraction and proliferation, but its role in atherogenesis has not been clarified. We investigated the effects of 5-HT on IL-6 synthesis in human vascular smooth muscle cells (VSMCs).

Methods and Results
—IL-6 levels in the culture medium of VSMCs were determined by ELISA. IL-6 mRNA accumulation was determined by use of a Quantikine mRNA colorimetric quantification kit. NF-κB activation was tested by gel retardation assay. 5-HT induced IL-6 production by VSMCs in a time- and dose-dependent manner, with increased IL-6 mRNA accumulation and nuclear factor-κB activation. The effect of 5-HT on IL-6 production was significantly inhibited by the 5-HT
2
receptor antagonist ketanserin and the selective 5-HT
2A
receptor antagonist sarpogrelate. Conversely, the 5-HT
2
receptor agonist α-methyl-5-HT increased IL-6 production. The protein kinase C (PKC) inhibitor calphostin C, but not the protein kinase A inhibitor KT5720, suppressed 5-HT–induced IL-6 production. The effect of 5-HT was also abolished in PKC-depleted VSMCs after pretreatment with phorbol 12-myristate 13-acetate for 24 hours.

Conclusions
—5-HT acts on 5-HT
2A
receptors and increases IL-6 synthesis in human VSMCs at least partially through a PKC-dependent pathway. These results suggested that 5-HT may contribute to inflammatory activation of the vessels during atherogenesis.
Circulating Immune Complexes in 50-Year-Old Men as a Strong and Independent Risk Factor for Myocardial Infarction
Authors: Mustafa Awder , Nityanand Soniya , Berglund Lars , Lithell Hans , Lefvert Ann Kari
Published: June 2012

Background
—Circulating immune complexes (CICs) and autoantibodies against oxidatively modified LDLs (oxLDLs) and cardiolipin occur in patients with atherosclerosis and myocardial infarction (MI). The ability of such CICs and antibodies to predict myocardial infarction (MI) was investigated in a prospective nested case-control study in which healthy 50-year-old men were followed for 20 years.

Methods and Results
—Two hundred fifty-seven men were included in the study, and 119 developed MI (39 died) between 50 and 70 years of age. One hundred thirty-eight randomly chosen men who did not develop MI up to 70 years of age served as controls. The prevalence of elevated levels of CICs and the concentration of CICs in men who developed MI were higher than in those who remained healthy. The concentration of CICs at age 50 was associated with a marked increased risk for MI, and this risk was independent of other conventionally recognized risk factors. There was a positive correlation between the levels of CIC and IgG antibodies to cardiolipin in men who developed MI. The level of IgG antibodies and the prevalence of elevated IgG and IgM antibodies to cardiolipin were higher in those who developed MI and had CICs than in those without CICs. Among men homozygous for C4 null alleles, those who developed MI had higher concentrations of CICs than did those who remained healthy.

Conclusions
—This prospective study shows that CICs alone or in combination with autoantibodies against cardiolipin in healthy males at 50 years of age predict subsequent MI between the age of and 70 years.
Abnormal Cardiac Autonomic Nervous Activity After Right Ventricular Outflow Tract Reconstruction
Authors: Ohuchi Hideo , Suzuki Hiroshi , Toyohara Keiko , Tatsumi Kimiko , Ono Yasuo , Arakaki Yoshio , Echigo Shigeyuki
Published: June 2012

Background
—There are few studies of cardiac autonomic nervous activity (CANA) in patients with congenital heart disease.

Methods and Results
—We evaluated CANA in 54 patients after closure of an atrial/ventricular septal defect (group A), 54 patients after successful right ventricular outflow tract reconstruction (RVOTR) (group B1), 35 RVOTR patients with residual stenosis (group B2), and 47 controls. Cardiac parasympathetic nervous activity (PSNA) was estimated by heart rate (HR) change after cholinergic blockade, HR variability, and arterial baroreflex sensitivity (BRS). Cardiac sympathetic nervous activity was estimated by the heart-to-mediastinum
123
I-metaiodobenzylguanidine activity ratio (H/M) and HR increase after isoproterenol infusion (β). HR response (ΔHR) and peak oxygen uptake (V̇
o
2
) were measured by exercise test. There was no difference in β among study groups. Group A exhibited mildly impaired PSNA, which recovered 1 year after surgery, and no change in H/M. Impaired PSNA and low H/M were found in groups B1 and B2 compared with controls (
P
<0.001), although the PSNA tended to recover 1 year after re-RVOTR. In group B1, PSNA and β were related to ΔHR, and BRS correlated inversely with the number of surgical procedures and age at RVOTR and positively correlated with the follow-up period, whereas ΔHR correlated with peak V̇
o
2
(
P
<0.01 to 0.001).

Conclusions
—After RVOTR, postsynaptic β-sensitivity is maintained and is important in ΔHR during exercise, as is PSNA, although ventricular sympathetic denervation is common. Impaired PSNA immediately after RVOTR improves with improved ΔHR and results in future amelioration of aerobic capacity, whereas ventricular sympathetic reinnervation is uncertain.
Noninvasive Ultrasound Imaging of Inflammation Using Microbubbles Targeted to Activated Leukocytes
Authors: Lindner Jonathan R. , Song Ji , Xu Fang , Klibanov Alexander L. , Singbartl Kai , Ley Klaus , Kaul Sanjiv
Published: June 2012

Background
—Lipid microbubbles used for perfusion imaging with ultrasound are retained within inflamed tissue because of complement-mediated attachment to leukocytes within venules. We hypothesized that incorporation of phosphatidylserine (PS) into the microbubble shell may enhance these interactions by amplifying complement activation and thereby allow ultrasound imaging of inflammation.

Methods and Results
—In 6 mice, intravital microscopy of tissue necrosis factor-α–treated cremaster muscle was performed to assess the microvascular behavior of fluorescein-labeled lipid microbubbles with and without PS in the shell. Ten minutes after intravenous injection, microbubble attachment to leukocytes within inflamed venules was greater for PS-containing than for standard lipid microbubbles (20±4 versus 10±3 per 20 optical fields,
P
<0.05). The ultrasound signal from retained microbubbles was assessed in the kidneys of 6 mice undergoing renal ischemia-reperfusion injury and in 6 control kidneys. The signal from retained microbubbles in control kidneys was low (<2.5 video intensity units) for both agents. After ischemia-reperfusion, the signal from retained microbubbles was 2-fold higher for PS-containing than for standard lipid microbubbles (18±6 versus 8±2 video intensity units,
P
<0.05). An excellent relation was found between the ultrasound signal from retained microbubbles and the degree of renal inflammation, assessed by tissue myeloperoxidase activity.

Conclusions
—We conclude that noninvasive assessment of inflammation is possible by ultrasound imaging of microbubbles targeted to activated leukocytes by the presence of PS in the lipid shell.
Catheter Ablation of Cardiac Autonomic Nerves for Prevention of Vagal Atrial Fibrillation
Authors: Schauerte Patrick , Scherlag Benjamin J. , Pitha Jan , Scherlag Michael A. , Reynolds Dwight , Lazzara Ralph , Jackman Warren M.
Published: June 2012

Background
—Vagal stimulation shortens the atrial effective refractory period (AERP) and maintains atrial fibrillation (AF). This study investigated whether the parasympathetic pathways that innervate the atria can be identified and ablated by use of transvenous catheter stimulation and radiofrequency current catheter ablation (RFCA) techniques.

Methods and Results
—In 11 dogs, AERPs were determined at 7 atrial sites during bilateral cervical vagal nerve stimulation (VNS) and electrical stimulation of the third fat pad (20 Hz) in the right pulmonary artery (RPA). VNS shortened the AERP at all sites (from 123±4 to 39±4 ms,
P
<0.001) and increased the covariance of AERP (COV-AERP) (from 9±3% to 27±13%,
P
<0.001). RPA stimulation shortened the AERP at all sites from 123±4 to 66±13 ms (
P
<0.001) and increased the COV-AERP from 9±3% to 30±12% (
P
<0.001). In 7 dogs, transvascular RFCA of the parasympathetic pathways along the RPA was performed, and in 3 dogs, additional RFCA of parasympathetic fibers along the inferior (n=2) or superior (n=1) vena cava was performed. RFCA blunted the AERP shortening at all sites during VNS (114±4 ms after RFCA), abolished the increase of COV-AERP during VNS (12±7% after RFCA), and led to an increase of the baseline AERP (123±4 ms before versus 127±3 ms after RFCA,
P
=0.002). Before RFCA, AF could be induced and maintained as long as VNS was continued, whereas after RFCA, AF was no longer inducible during VNS.

Conclusions
—Transvascular atrial parasympathetic nerve system modification by RFCA abolishes vagally mediated AF. This antifibrillatory procedure may provide a foundation for investigating the usefulness of neural ablation in chronic animal models of AF and eventually in patients with AF and high vagal tone.
Primary Pulmonary Hypertension
Authors: Archer Stephen , Rich Stuart
Published: June 2012

Abstract
—Primary pulmonary hypertension (PPH) is a syndrome of dyspnea, chest pain, and syncope defined by increased pulmonary vascular resistance and the absence of a known cause. It also occurs in a familial form, which is linked to unidentified genes on chromosome 2. This syndrome is characterized by abnormalities of pulmonary vascular biology in each compartment of the blood vessel. The lumen has a prothrombotic diathesis, the endothelium displays an excessive production of vasoconstrictors relative to vasodilators, and the smooth muscle cells are depolarized and calcium-overloaded, which is due in part to reduced expression of voltage-gated potassium channels (Kv). This causes vasoconstriction and may promote cell proliferation. The adventitia displays excessive remodeling, which is associated with exaggerated metalloproteinase and elastase activity. Conceptually, PPH seems to require a permissive genotype, a susceptible phenotype (eg, endothelial dysfunction) and, in many cases, an exogenous trigger (eg, an anorexigen). Although there is not a generally accepted, unifying hypothesis regarding its cause, impaired function and the expression of vascular and platelet Kv channels suggest PPH may be a disease of the ion channels. Abnormal matrix metalloproteinase and elastase activity could also explain the abnormal vascular tone, platelet activation, and remodeling in PPH. Although calcium-channel blockers and prostacyclin, particularly when coadministered with warfarin, improve survival, PPH has a 5-year mortality rate of ≈50%. Pharmacological and gene therapies aimed at enhancing the activity of prostacyclin, nitric oxide synthases, and Kv channels or at inhibiting endothelin and matrix metalloproteinases are promising areas for future development.
Simvastatin Improves Disturbed Endothelial Barrier Function
Authors: Amerongen Geerten P. van Nieuw , Vermeer Mario A. , Nègre-Aminou Pascale , Lankelma Jan , Emeis Jef J. , van Hinsbergh Victor W. M.
Published: June 2012

Background
—Recent clinical trials have established that inhibitors of the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (statins) reduce the risk of acute coronary events. These effects of statins cannot be fully explained by their lipid-lowering potential. Improved endothelial function may contribute to the positive effects of statin treatment.

Methods and Results
—In the present study, we report that simvastatin reduces endothelial barrier dysfunction, which is associated with the development of atherosclerosis. Treatment of human umbilical vein endothelial cells for 24 hours with 5 μmol/L simvastatin reduced the thrombin-induced endothelial barrier dysfunction in vitro by 55±3%, as assessed by the passage of peroxidase through human umbilical vein endothelial cell monolayers. Similar effects were found on the thrombin-induced passage of
125
I-LDL through human aortic endothelial cell monolayers. This reduction in barrier dysfunction by simvastatin was both dose and time dependent and was accompanied by a reduction in the thrombin-induced formation of stress fibers and focal adhesions and membrane association of RhoA. Simvastatin treatment had no effect on intracellular cAMP levels. In Watanabe heritable hyperlipidemic rabbits, treatment for 1 month with 15 mg/kg simvastatin reduced vascular leakage in both the thoracic and abdominal part of the aorta, as evidenced by the Evans blue dye exclusion test. The decreased permeability was not accompanied by a reduction of oil red O–stainable atherosclerotic lesions.

Conclusions
—These data show that simvastatin, in a relatively high concentration, improves disturbed endothelial barrier function both in vitro and in vivo. The data also support the beneficial effects of simvastatin in acute coronary events by mechanisms other than its lipid-lowering effect
.
1α,25-Dihydroxyvitamin D
3
and Its Potent Synthetic Analogs Downregulate Tissue Factor and Upregulate Thrombomodulin Expression in Monocytic Cells, Counteracting the Effects of Tumor Necrosis Factor and Oxidized LDL
Authors: Ohsawa Mai , Koyama Takatoshi , Yamamoto Keiko , Hirosawa Shinsaku , Kamei Sachiko , Kamiyama Ryuichi
Published: June 2012

Background
—We have recently found that a hormonally active form of vitamin D, 1α,25-dihydroxyvitamin D
3
[1,25(OH)
2
D
3
], exerts anticoagulant effects by upregulating the expression of an anticoagulant glycoprotein, thrombomodulin (TM), and downregulating the expression of a critical coagulation factor, tissue factor (TF), in monocytic cells including human peripheral monocytes. In this study, we investigated the counteracting effects of 1,25(OH)
2
D
3
and its potent analogs on TF induction and TM downregulation by tumor necrosis factor and oxidized LDL in monocytic cells and the modulatory effects of potent analogs on TF and TM expression.

Methods and Results
—Effects of 1,25(OH)
2
D
3
and its potent synthetic analogs (22R)-22-methyl-20-epi-1,25(OH)
2
D
3
(KY3) and 22-oxacalcitriol on TF and TM antigen levels, cell surface activities, and mRNA levels in monocytic cells were examined. 1,25(OH)
2
D
3
and its potent analogs showed anticoagulant effects in monocytic cells by downregulating TF and upregulating TM expression, counteracting the effects of tumor necrosis factor and oxidized LDL. KY3 was most potent in its regulatory effect on TF and TM expression.

Conclusions
—Because KY3 has the highest affinity for vitamin D receptor, our findings suggest that TF and TM regulation by 1,25(OH)
2
D
3
analogs is also mediated by vitamin D receptor. The 1,25(OH)
2
D
3
analogs KY3 and 22-oxacalcitriol may have the potential to serve as an agent for preventing and treating atherosclerotic and other cytokine-mediated thrombotic diseases and as a tool for studying the molecular mechanisms of TF and TM regulation.
Chronic Hypoxia Stimulates Periarterial Sympathetic Nerve Development in Chicken Embryo
Authors: Ruijtenbeek K. , le Noble F. A. C. , Janssen G. M. J. , Kessels C. G. A. , Fazzi G. E. , Blanco C. E. , De Mey J. G. R.
Published: June 2012

Background
—Epidemiological findings suggest an association between low-for-age birth weight and the risk to develop coronary heart diseases in adulthood. During pregnancy, an imbalance between fetal demands and supply may result in permanent alterations of neuroendocrine development in the fetus. We evaluated whether chronic prenatal hypoxia increases arterial sympathetic innervation.

Methods and Results
—Chicken embryos were maintained from 0.3 to 0.9 of the 21-day incubation period under normoxic (21% O
2
) or hypoxic conditions (15% O
2
). At 0.9 incubation, the degree of sympathetic innervation of the embryonic femoral artery was determined by biochemical, histological, and functional (in vitro contractile reactivity) techniques. Chronic hypoxia increased embryonic mortality (32% versus 13%), reduced body weight (21.9±0.4 versus 25.4±0.6 g), increased femoral artery norepinephrine (NE) content (78.4±9.4 versus 57.5±5.0 pg/mm vessel length), and increased the density of periarterial sympathetic nerve fibers (14.4±0.7 versus 12.5±0.6 counts/10
4
μm
2
). Arteries from hypoxic embryos were less sensitive to NE (pD
2
, 5.99±0.04 versus 6.21±0.10). In the presence of cocaine, however, differences in sensitivity were no longer present. In the embryonic heart, NE content (156.9±11.0 versus 108.1±14.7 pg/mg wet wt) was also increased after chronic hypoxia.

Conclusions
—In the chicken embryo, chronic moderate hypoxia leads to sympathetic hyperinnervation of the arterial system. In humans, an analogous mechanism may increase the risk for cardiovascular disease in adult life.
Immediate Changes of Collateral Function After Successful Recanalization of Chronic Total Coronary Occlusions
Authors: Werner Gerald S. , Richartz Barbara M. , Gastmann Oliver , Ferrari Markus , Figulla Hans R.
Published: June 2012

Background
—Coronary collaterals are essential to maintain myocardial function in chronic total coronary occlusions (TCOs). The aim of the present study was to assess the collateral circulation in TCOs before coronary angioplasty and to determine the recruitable collateral perfusion after recanalization by use of intracoronary Doppler flow velocimetry.

Methods and Results
—In 21 patients with TCOs (duration >4 weeks), Doppler recordings of basal collateral flow were obtained before the first balloon inflation. Angioplasty was performed with stent implantation in all lesions. At the end of the procedure, recruitable collateral flow was measured during a repeat balloon inflation. The collateral flow index (CFI) was calculated from the velocity integral during the occlusion/velocity integral of antegrade flow. In 17 of 21 patients, angiography was repeated after 24 hours, and CFI was reassessed. Average peak velocity of collateral flow was 10.9±5.6 cm/s with a predominantly systolic flow (diastolic/systolic velocity ratio <0.5) compared with antegrade flow (diastolic/systolic velocity ratio >1.5). After recanalization, the average peak velocity of recruitable collateral flow dropped by >50% to 4.7±2.5 cm/s. CFI fell from 0.48±0.25 to 0.21±0.16 (
P
<0.001). There was no further change of CFI during the following 24 hours. CFI was higher in patients with preserved regional ventricular function than in those with akinetic myocardium (0.57±0.23 versus 0.38±0.12,
P
<0.05).

Conclusions
—Collateral circulation in TCO provided 50% of antegrade coronary flow. A considerable fraction of collateral flow was immediately lost after recanalization, indicating that TCO may not remain protected from future ischemic events by a well-developed collateral function.
Usefulness of Unipolar Electrograms to Detect Isthmus Block After Radiofrequency Ablation of Typical Atrial Flutter
Authors: Villacastin Julian , Almendral Jesus , Arenal Angel , Castellano Nicasio P. , Gonzalez Sergio , Ortiz Mercedes , García Javier , Vallbona Bartolome , Moreno Javier , Portales Javier F. , Torrecilla Esteban G.
Published: June 2012

Background
—RS morphology of the unipolar electrogram is associated with propagation of the wave front through the exploring electrode, whereas positive uniphasic (R) unipolar electrograms are characteristic of the end of activation.

Methods and Results
—Unipolar electrograms were recorded in 45 consecutive patients with atrial flutter who were undergoing radiofrequency ablation (RFA). Bidirectional cavotricuspid isthmus (CTI) block was achieved in 44 patients. The unipolar electrogram obtained before RFA at the low anterolateral right atrium during coronary sinus pacing changed from RS, rS, or QS to R or Rs in all patients after clockwise CTI block was obtained. The morphology of unipolar electrograms recorded close to the coronary sinus during pacing from the low anterolateral right atrium changed from RS or rS to R or Rs in all but 4 patients after counterclockwise CTI block. In the patient in whom CTI block was not achieved, the RS morphology of the unipolar electrogram remained unchanged. In 18 patients, the results of the RFA were assessed with only the unipolar electrogram. The unipolar electrogram correctly predicted 100% and 89% of the cases of clockwise and counterclockwise CTI block, respectively.

Conclusions
—The creation of CTI block is associated with an easily detectable loss of negative components and development of an R or Rs pattern of the unipolar electrogram recorded close to the ablation line while pacing at the opposite side of the CTI.
Ischemia-Induced Coronary Collateral Growth Is Dependent on Vascular Endothelial Growth Factor and Nitric Oxide
Authors: Matsunaga Toshiro , Warltier David C. , Weihrauch Dorothee W. , Moniz Melinda , Tessmer John , Chilian William M.
Published: June 2012

Background
—We hypothesized that ischemia-induced expression of vascular endothelial growth factor (VEGF) and the production of NO stimulate coronary collateral growth.

Methods and Results
—To test this hypothesis, we measured coronary collateral blood flow and VEGF expression in myocardial interstitial fluid in a canine model of repetitive myocardial ischemia under control conditions and during antagonism of NO synthase. Collateralization was induced by multiple (1/h; 8/d), brief (2 minutes) occlusions of the left anterior descending coronary artery for 21 days. In controls, collateral blood flow (microspheres) progressively increased to 89±9 mL · min
−1
· 100 g
−1
on day 21, which was equivalent to perfusion in the normal zone. Reactive hyperemic responses (a measure of the severity of ischemia) decreased as collateral blood flow increased. In
N
G
-nitro-
l
-arginine methyl ester (L-NAME)– and L-NAME+nifedipine–treated dogs, to block the production of NO and control hypertension, respectively, collateral blood flow did not increase and reactive hyperemia was robust throughout the occlusion protocol (
P
<0.01 versus control). VEGF expression (Western analyses of VEGF
164
in myocardial interstitial fluid) in controls peaked at day 3 of the repetitive occlusions but waned thereafter. In sham-operated dogs (instrumentation but no occlusions), expression of VEGF was low during the entire protocol. In contrast, VEGF expression was elevated throughout the 21 days of repetitive occlusions after L-NAME. Reverse transcriptase–polymerase chain reaction analyses revealed that the predominant splice variant expressed was VEGF
164
.

Conclusions
—NO is an important regulator of coronary collateral growth, and the expression of VEGF is induced by ischemia. Furthermore, the induction of coronary collateralization by VEGF appears to require the production of NO.
Hibernation in Noncontracting Mammalian Cardiomyocytes
Authors: Casey Tammy M. , Arthur Peter G.
Published: June 2012

Background
—The aim of the present study was to establish whether isolated neonatal mammalian cardiomyocytes were capable of downregulating energy-using processes other than contraction while maintaining metabolic stability when oxygen availability was reduced.

Methods and Results
—Metabolic response of cardiomyocytes was investigated under moderate (5 to 6 μmol/L) and severe (2 to 3 μmol/L) forms of hypoxia. Cells exposed to oxygen concentrations of 5 to 6 μmol/L exhibited rates of oxygen consumption, which were decreased to 64% of normoxic rates. Rates of cellular energy usage were decreased because this reduced rate of oxygen consumption was not associated with either decreased intracellular ATP and phosphocreatine concentrations or a compensatory switch to glycolysis. When cells were exposed to oxygen concentrations of 2 to 3 μmol/L, rates of oxygen consumption decreased to 9% of normoxic rates. This decreased rate of oxygen consumption was associated with energetic stress, because a significant switch to glycolysis occurred and intracellular phosphocreatine concentrations were decreased by 40%. Rates of cellular energy usage were further decreased as indicated by stable intracellular ATP concentrations.

Conclusions
—Our results suggest that isolated cardiomyocytes are capable of downregulating energy-consuming processes other than contraction when oxygen supply is decreased. Regions of myocardial tissue are also capable of downregulating metabolic activity during ischemia by shutting down contractile activity (myocardial hibernation). We suggest that metabolic downregulation associated with myocardial hibernation may not be exclusively due to reduced rates of contractile activity. Other energy-using processes (eg, protein synthesis, mRNA synthesis, ion channel activity, and proton leak) may also be shut down.
Hirudin Reduces Tissue Factor Expression and Attenuates Graft Arteriosclerosis in Rat Cardiac Allografts
Authors: Hölschermann Hans , Bohle Rainer M. , Schmidt Heiko , Zeller Hagen , Fink Ludger , Stahl Ulrich , Grimm Helmut , Tillmanns Harald , Haberbosch Werner
Published: June 2012

Background
—Intravascular clotting has been implicated in the pathogenesis of cardiac allograft vasculopathy (CAV). We previously identified the expression of tissue factor (TF), the primary cellular initiator of blood coagulation, within the coronary intima, which was associated with neointimal thickening. In the present study, the effect of recombinant hirudin on CAV was assessed in Lewis to Fisher rat heterotopic cardiac allografts.

Methods and Results
—Transplant recipients were randomized to a control group (n=10) and a hirudin-treated group (n=12; 2 mg · kg
−1
· d
−1
SC). Histological evaluations of rejection, CAV, and TF staining were performed 120 days after transplantation. No significant differences were observed between the 2 groups with respect to the degree of rejection. Hirudin significantly (
P
<0.05) suppressed the development of CAV in the graft microvessels, but it was less effective in large coronary arteries. Graft intimal cells, isolated by laser-assisted cell picking, showed a marked upregulation of TF gene transcription, which was prevented by hirudin (
P
<0.01). As demonstrated by immunohistochemistry and quantitative analyses of TF mRNA levels by real-time polymerase chain reaction, hirudin treatment resulted in a significant reduction of TF protein and mRNA expression (
P
<0.001).

Conclusions
—Treatment with hirudin in this rat cardiac transplant model inhibited TF expression and decreased neointimal hyperplasia. These results suggest that TF inhibition by hirudin, in addition to its direct effect on thrombin, may attenuate the hypercoagulable state and prevent the development of CAV at least in restricted sites of the graft coronary vasculature.
Association of Coronary Heart Disease Risk Factors With Microscopic Qualities of Coronary Atherosclerosis in Youth
Authors: McGill Henry C. , McMahan C. Alex , Zieske Arthur W. , Tracy Richard E. , Malcom Gray T. , Herderick Edward E. , Strong Jack P.
Published: June 2012

Background
—This study examined whether atherosclerosis in young people is associated with the risk factors for clinical coronary heart disease (CHD).

Methods and Results
—Histological sections of left anterior descending coronary arteries (LADs) from 760 autopsied 15- to 34-year-old victims of accidents, homicides, and suicides were graded according to the American Heart Association (AHA) system and computerized morphometry. Risk factors (dyslipoproteinemia, smoking, hypertension, obesity, impaired glucose tolerance) were assessed by postmortem measurements. Approximately 2% of 15- to 19-year-old men and 20% of 30- to 34-year-old men had AHA grade 4 or 5 (advanced) lesions. No 15- to 19-year-old women had grade 4 or 5 lesions; 8% of 30- to 34-year-old women had such lesions. Approximately 19% of 30- to 34-year-old men and 8% of 30- to 34-year-old women had atherosclerotic stenosis ≥40% in the LAD. AHA grade 2 or 3 lesions (fatty streaks), grade 4 or 5 lesions, and stenosis ≥40% were associated with non-HDL cholesterol ≥4.14 mmol/L (160 mg/dL). AHA grade 2 or 3 lesions were associated with HDL cholesterol <0.91 mmol/L (35 mg/dL) and smoking. AHA grade 4 or 5 lesions were associated with obesity (body mass index ≥30 kg/m
2
) and hypertension (mean arterial pressure ≥110 mm Hg).

Conclusions
—Young Americans have a high prevalence of advanced atherosclerotic coronary artery plaques with qualities indicating vulnerability to rupture. Early atherosclerosis is influenced by the risk factors for clinical CHD. Long-range prevention of CHD must begin in adolescence or young adulthood.
Electrophysiological Mapping and Ablation of Intra-Atrial Reentry Tachycardia After Fontan Surgery With the Use of a Noncontact Mapping System
Authors: Betts Timothy R. , Roberts Paul R. , Allen Stuart A. , Salmon Anthony P. , Keeton Barry R. , Haw Marcus P. , Morgan John M.
Published: June 2012

Background
—Atrial tachyarrhythmias are a complication of Fontan surgery. Conventional electrophysiological mapping and ablation techniques are limited by the complex anatomic and surgical substrate and a high arrhythmia recurrence rate. This study investigates the use of noncontact mapping to identify arrhythmia circuits and guide ablation in Fontan patients.

Methods and Results
—Eleven arrhythmias were recorded in 6 patients. Noncontact mapping improved recognition of the anatomic and surgical substrate and identified exit sites from zones of slow conduction in all clinical arrhythmias. Radiofrequency linear lesions were targeted across these critical zones in 5 patients. One patient underwent surgical cryotherapy. Although immediate success was achieved in 3 of 5 patients with radiofrequency ablation, 2 patients had a recurrence after a mean of 6.4 months of follow-up. The patient who underwent cryoablation remains free of arrhythmias.

Conclusions
—Noncontact mapping can identify arrhythmia circuits in the Fontan atrium and guide placement of ablation lesions. Arrhythmia recurrence is high, possibly because of inadequate lesion creation rather than inaccurate mapping and lesion targeting.
Myocardial Blood Flow and Myocardial Uptake of
201
Tl and
99m
Tc-Sestamibi During Coronary Vasodilation Induced by CGS-21680, a Selective Adenosine A
2A
Receptor Agonist
Authors: He Zuo-Xiang , Cwajg Eduardo , Hwang Wayne , Hartley Craig J. , Funk Etai , Michael Lloyd H. , Verani Mario S.
Published: June 2012

Background
—We investigated the hemodynamic and coronary vasodilatory effects of CGS-21680, a potent selective adenosine A
2A
agonist, as well as its potential use as a new stress modality in combination with perfusion scintigraphy.

Methods and Results
—A stenosis of the left anterior descending coronary artery (LAD) was produced in dogs to reduce the reactive hyperemic response to <20%. Adenosine and CGS-21680 were then separately infused to maximize left circumflex coronary artery (LCx) flow velocity.
201
Tl (0.5 mCi) and
99m
Tc-sestamibi (5 mCi) were injected at the maximal dose of CGS-21680. Heart rate decreased with adenosine but increased during CGS-21680 infusion (
P
<0.005). The decrease in systolic blood pressure was more prominent with adenosine than with CGS-21680 (
P
<0.005). In the control LCx zone, maximal myocardial blood flow (MBF) (measured by radioactive microspheres) increased 3.1-fold during adenosine infusion (
P
<0.005) and 3.8-fold during CGS-21680 infusion (
P
<0.005). In the stenotic LAD zone, MBF did not change significantly. During adenosine and CGS-21680 infusion, stenosis/control zone MBF ratios were comparable (0.32±0.11 versus 0.27±0.10,
P
=NS), and transmural
201
Tl and
99m
Tc-sestamibi count-activity ratios (0.48±0.11 and 0.51±0.09, respectively) were also comparable (
P
=NS). Myocardial scintigraphy uncovered perfusion defects in all dogs.

Conclusions
—CGS-21680 elicits coronary vasodilation comparable to that of adenosine and produces profound heterogeneity of MBF and of
201
Tl and
99m
Tc-sestamibi myocardial uptake, rendering it a promising agent for pharmacological myocardial perfusion imaging.
Involvement of Cytokines in the Mechanism of Whole-Body Hyperthermia-Induced Cardioprotection
Authors: Yamashita Nobushige , Hoshida Shiro , Otsu Kinya , Taniguchi Naoyuki , Kuzuya Tsunehiko , Hori Masatsugu
Published: June 2012

Background
—Hyperthermia increases cardiac tolerance to ischemia/reperfusion injury and activates manganese superoxide dismutase (Mn-SOD), an intrinsic radical scavenger, in myocardium in a biphasic manner. Tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) induced a biphasic cardioprotection that corresponded to the activation of Mn-SOD. However, a direct association between Mn-SOD activation in myocardium and the acquisition of tolerance to ischemia/reperfusion injury induced by hyperthermia and the involvement of the cytokines in the signal transduction pathway for the hyperthermia-induced cardioprotection have not yet been elucidated.

Methods and Results
—Hyperthermia was induced in anesthetized rats by placement in a temperature-controlled water bath. At 0.5 and 72 hours after hyperthermia, ischemia was induced by occlusion of the left coronary artery for 20 minutes, followed by reperfusion for 48 hours. Inhibition of the increases in Mn-SOD content and activity 72 hours after hyperthermia by the administration of antisense oligodeoxynucleotides to Mn-SOD abolished the expected decrease in myocardial infarct size. The simultaneous administration of neutralizing antibodies to TNF-α and IL-1β before hyperthermia abolished the biphasic cardioprotection and increase in Mn-SOD activity.

Conclusions
—The increase in Mn-SOD activity mediated through the production of TNF-α and IL-1β by whole-body hyperthermia is important in the acquisition of early- and late-phase cardioprotection against ischemia/reperfusion injury in rats.
Alcohol Consumption and Risk of Coronary Heart Disease by Diabetes Status
Authors: Ajani Umed A. , Gaziano J. Michael , Lotufo Paulo A. , Liu Simin , Hennekens Charles H. , Buring Julie E. , Manson JoAnn E.
Published: June 2012

Background
—An inverse association between moderate alcohol consumption and coronary heart disease (CHD) has been observed in several epidemiological studies. To assess whether a similar association exists among diabetics, we examined the relation between light to moderate alcohol consumption and CHD in men with and without diabetes mellitus in a prospective cohort study.

Methods and Results
—A total of 87 938 US physicians (2790 with diagnosed diabetes mellitus) who were invited to participate in the Physicians’ Health Study and were free of myocardial infarction, stroke, cancer, or liver disease at baseline were followed for an average of 5.5 years for death with CHD as the underlying cause. During 480 876 person-years of follow-up, 850 deaths caused by CHD were documented: 717 deaths among nondiabetic men and 133 deaths among diabetic men. Among men without diabetes at baseline, the relative risk estimates for those reporting rarely/never, monthly, weekly, and daily alcohol consumption were 1.00 (referent), 1.02, 0.82, and 0.61 (95% CI 0.49 to 0.78;
P
for trend <0.0001) after adjustment for age, aspirin use, smoking, physical activity, body mass index, and history of angina, hypertension, and high cholesterol. Among men with diabetes at baseline, the relative risk estimates were 1.00 (referent), 1.11, 0.67, and 0.42 (95% CI 0.23 to 0.77;
P
for trend=0.0019).

Conclusions
—These results suggest that light to moderate alcohol consumption is associated with similar risk reductions in CHD among diabetic and nondiabetic men.
True 3-Dimensional Reconstruction of Coronary Arteries in Patients by Fusion of Angiography and IVUS (ANGUS) and Its Quantitative Validation
Authors: Slager Cornelis J. , Wentzel Jolanda J. , Schuurbiers Johan C. H. , Oomen Jan A. F. , Kloet Jeroen , Krams Rob , von Birgelen Clemens , van der Giessen Willem J. , Serruys Patrick W. , de Feyter Pim J.
Published: June 2012

Background
—True 3D reconstruction of coronary arteries in patients based on intravascular ultrasound (IVUS) may be achieved by fusing angiographic and IVUS information (ANGUS). The clinical applicability of ANGUS was tested, and its accuracy was evaluated quantitatively.

Methods and Results
—In 16 patients who were investigated 6 months after stent implantation, a sheath-based catheter was used to acquire IVUS images during an R-wave–triggered, motorized stepped pullback. First, a single set of end-diastolic biplane angiographic images documented the 3D location of the catheter at the beginning of pullback. From this set, the 3D pullback trajectory was predicted. Second, contours of the lumen or stent obtained from IVUS were fused with the 3D trajectory. Third, the angular rotation of the reconstruction was optimized by quantitative matching of the silhouettes of the 3D reconstruction with the actual biplane images. Reconstructions were obtained in 12 patients. The number of pullback steps, which determines the pullback length, closely agreed with the reconstructed path length (
r
=0.99). Geometric measurements in silhouette images of the 3D reconstructions showed high correlation (0.84 to 0.97) with corresponding measurements in the actual biplane angiographic images.

Conclusions
—With ANGUS, 3D reconstructions of coronary arteries can be successfully and accurately obtained in the majority of patients.
Estimates of Repolarization Dispersion From Electrocardiographic Measurements
Authors: Fuller Marc S. , Sándor György , Punske Bonnie , Taccardi Bruno , MacLeod Rob S. , Ershler Phillip R. , Green Larry S. , Lux Robert L.
Published: June 2012

Background
—Repolarization dispersion (Rd) is frequently mentioned as a predictor of cardiac abnormalities. We present a new measure of Rd based on the root-mean-square (RMS) curve of an ECG lead set and compare its performance with that of the commonly used QT dispersion (QTd) measure with the use of recovery times measured from directly recorded canine electrograms.

Methods and Results
—Using isolated, perfused canine hearts suspended in a torso-shaped electrolytic tank, we simultaneously recorded electrograms from 64 epicardial sites and ECGs from 192 “body surface” sites. RMS curves were derived from 4 lead sets: epicardial, body surface, precordial, and a 6-lead optimal set. Repolarization was altered by changing cycle length, temperature, and activation sequence. Rd, calculated directly from recovery times of the 64 epicardial potentials, was then compared with the width of the T wave of the RMS curve and with QTd for each of these 4 lead sets. The correlation between T-wave width and Rd for each lead set, respectively, was epicardium, 0.91; body surface, 0.84; precordial, 0.72; and optimal leads, 0.81. The correlation between QTd and Rd for each lead set was epicardium, 0.46; body surface, 0.47; precordial, 0.17; and optimal leads, 0.11.

Conclusions
—RMS curve analysis provides an accurate method of estimating Rd from the body surface. In contrast, QTd analysis provides a poor estimate of Rd.
G-Protein β
3
-Subunit 825T Allele Is Associated With Enhanced Human Atrial Inward Rectifier Potassium Currents
Authors: Dobrev D. , Wettwer E. , Himmel H. M. , Kortner A. , Kuhlisch E. , Schüler S. , Siffert W. , Ravens U.
Published: June 2012

Background
—A C825T polymorphism was recently identified in the human gene encoding for the β
3
-subunit of heterotrimeric G proteins. The 825T allele is associated with a splice variant of Gβ
3
and enhanced signal transduction. We hypothesized that patients carrying the 825T allele exhibit the modified Gβ
3
phenotype. The resulting enhancement of signal transduction should be detectable in the Gβγ-dimer–mediated acetylcholine-stimulated K
+
current (
I
K,ACh
).

Methods and Results
—Seventy patients undergoing cardiac surgery were genotyped for the C825T polymorphism. In right atrial myocytes from these patients, the inward rectifier K
+
currents (
I
K1
,
I
K,ACh
) were studied with the whole-cell patch-clamp technique. Background current
I
K1
was measured with depolarizing ramp pulses and quantified as inward current at −100 mV; mean amplitudes were (pA/pF) 4.98±0.49 (n=30/93 patients/cells) in patients with CC genotype, 4.25±0.36 (n=31/121 patients/cells) with TC, and 7.46±1.14 (n=9/32 patients/cells;
P
<0.05) with TT. Conversely, mean
I
K,ACh
, which is maximally activated by carbachol (2 μmol/L), was reduced in patients with TT genotype (pA/pF, 4.30±1.33, n=9/27 patients/cells;
P
<0.05) compared with the other 2 groups (6.56±0.54, n=30/80 and 6.16±0.45, n=31/117 patients/cells, for CC and TC genotype, respectively). Essentially similar results were obtained with adenosine (1 mmol/L).

Conclusions
—We found an association between the Gβ
3
825T allele and amplitude of human atrial
I
K1
and
I
K,ACh
. Increased background current density in TT carriers could shorten action potential duration and may be due to
I
K,ACh
being constitutively active in this genotype.
Epidemiology of Hypertrophic Cardiomyopathy–Related Death
Authors: Maron Barry J. , Olivotto Iacopo , Spirito Paolo , Casey Susan A. , Bellone Pietro , Gohman Thomas E. , Graham Kevin J. , Burton David A. , Cecchi Franco
Published: June 2012

Background
—Death resulting from hypertrophic cardiomyopathy (HCM), particularly when sudden, has been reported to be largely confined to young persons. These data emanated from tertiary HCM centers with highly selected referral patterns skewed toward high-risk patients.

Methods and Results
—The present analysis was undertaken in an international population of 744 consecutively enrolled and largely unselected patients more representative of the overall HCM spectrum. HCM-related death occurred in 86 patients (12%) over 8±7 years (mean±SD). Three distinctive modes of death were as follows: (1) sudden and unexpected (51%; age, 45±20 years); (2) progressive heart failure (36%; age, 56±19 years); and (3) HCM-related stroke associated with atrial fibrillation (13%; age, 73±14 years). Sudden death was most common in young patients, whereas heart failure– and stroke-related deaths occurred more frequently in midlife and beyond. However, neither sudden nor heart failure–related death showed a statistically significant, disproportionate age distribution (
P
=0.06 and 0.5, respectively). Stroke-related deaths did occur disproportionately in older patients (
P
=0.002). Of the 45 patients who died suddenly, most (71%) had no or mild symptoms, and 7 (16%) participated in moderate to severe physical activities at the time of death.

Conclusions
—HCM-related cardiovascular death occurred suddenly, or as a result of heart failure or stroke, largely during different phases of life in a prospectively assembled, regionally based, and predominantly unselected patient cohort. Although most sudden deaths occurred in adolescents and young adults, such catastrophes were not confined to patients of these ages and extended to later phases of life. This revised clinical profile suggests that generally held epidemiological tenants for HCM have been influenced considerably by skewed reporting from highly selected populations. These data are likely to importantly affect risk stratification and treatment strategies importantly for the prevention of sudden death in HCM.
Plasma Brain Natriuretic Peptide as a Prognostic Indicator in Patients With Primary Pulmonary Hypertension
Authors: Nagaya Noritoshi , Nishikimi Toshio , Uematsu Masaaki , Satoh Toru , Kyotani Shingo , Sakamaki Fumio , Kakishita Mikio , Fukushima Kengo , Okano Yoshiaki , Nakanishi Norifumi , Miyatake Kunio , Kangawa Kenji
Published: June 2012

Background
—Plasma brain natriuretic peptide (BNP) level increases in proportion to the degree of right ventricular dysfunction in pulmonary hypertension. We sought to assess the prognostic significance of plasma BNP in patients with primary pulmonary hypertension (PPH).

Methods and Results
—Plasma BNP was measured in 60 patients with PPH at diagnostic catheterization, together with atrial natriuretic peptide, norepinephrine, and epinephrine. Measurements were repeated in 53 patients after a mean follow-up period of 3 months. Forty-nine of the patients received intravenous or oral prostacyclin. During a mean follow-up period of 24 months, 18 patients died of cardiopulmonary causes. According to multivariate analysis, baseline plasma BNP was an independent predictor of mortality. Patients with a supramedian level of baseline BNP (≥150 pg/mL) had a significantly lower survival rate than those with an inframedian level, according to Kaplan-Meier survival curves (
P
<0.05). Plasma BNP in survivors decreased significantly during the follow-up (217±38 to 149±30 pg/mL,
P
<0.05), whereas that in nonsurvivors increased (365±77 to 544±68 pg/mL,
P
<0.05). Thus, survival was strikingly worse for patients with a supramedian value of follow-up BNP (≥180 pg/mL) than for those with an inframedian value (
P
<0.0001).

Conclusions
—A high level of plasma BNP, and in particular, a further increase in plasma BNP during follow-up, may have a strong, independent association with increased mortality rates in patients with PPH.
Changes in Surface Expression of Platelet Membrane Glycoproteins and Progression of Heart Transplant Vasculopathy
Authors: Fateh-Moghadam Suzanne , Bocksch Wolfgang , Ruf Andreas , Dickfeld Timm , Schartl Michael , Pogátsa-Murray Gisela , Hetzer Roland , Fleck Eckart , Gawaz Meinrad
Published: June 2012

Background
—Transplant vasculopathy is the main limiting factor of the long-term success of heart transplantation. We sought to establish the role of platelets in the development and progression of transplant vasculopathy.

Methods and Results
—Platelet analysis and intracoronary ultrasound examination were performed in 78 heart transplant recipients. Quantitative intracoronary ultrasound was used to define the severity of disease at baseline (48.8±4.5 months after transplantation) and at 1-year follow-up. Platelet activation was assessed with the use of immunological surface markers of activation (ligand-induced binding site 1 [LIBS-1], P-selectin, GPIIb-IIIa) and flow cytometry. We found that LIBS-1 immunoreactivity was significantly increased in patients with diffuse disease when compared with focal transplant disease (median [quartile], 27[14, 64] versus 18[7.9, 47],
P
=0.04). In a logistic regression model, we found that LIBS-1 was an independent predictor for the presence and progression of diffuse transplant vasculopathy (
P
=0.04). Patients with enhanced LIBS-1 levels (>75% quartile) had a 3.3-fold increased relative risk (95% CI 1.8 and 18.9,
P
=0.002) for the presence of diffuse transplant vasculopathy. When a cutoff value of 16.5 for the level of LIBS-1 was used, patients had a 4.8-fold increased relative risk (95% CI 1.9 and 12.5,
P
<0.01) for the progression of transplant vasculopathy.

Conclusions
—Enhanced platelet activation is strongly associated with the development and progression of transplant vasculopathy. Understanding the underlying pathophysiological mechanisms might contribute to the development of treatment strategies to prevent transplant vasculopathy.