bluuebunny/crossref_metadata_2025 huggingface dataset:
Angiotensin II Type 1A Receptor Knockout Mice Display Less Left Ventricular Remodeling and Improved Survival After Myocardial Infarction
Authors: Harada Koichiro , Sugaya Takeshi , Murakami Kazuo , Yazaki Yoshio , Komuro Issei
Published: June 2012

Background
—Angiotensin II (Ang II) has been implicated in ventricular remodeling after myocardial infarction (MI), which is an important determinant for prognosis after MI. The aim of this study was to determine whether Ang II type 1A receptor (AT
1A
)–mediated Ang II signals are critically involved in the mortality and LV remodeling after MI.

Methods and Results
—We examined survival, cardiac geometry and function, cardiac fibrosis, and gene expression of AT
1A
knockout (KO) mice and wild-type (WT) mice at 1 and 4 weeks after large MI. The survival rate was higher in KO mice than in WT mice at 4 weeks after MI. All WT survivors showed severe heart failure, detected by marked increases in both RV weight and lung weight. LV remodeling, such as the development of LV dilatation, LV dysfunction, and cardiac fibrosis at the noninfarcted area, were comparable in both kinds of mice at 1 week after MI. At 4 weeks after MI, however, WT mice showed more marked remodeling than KO mice. mRNA levels of AT
1
at the noninfarcted area were increased from 1 to 4 weeks after MI only in WT mice, whereas levels of AT
2
were not changed by MI in either kind of mouse. Accompanied by the development of geometric and structural remodeling, expression of fetal-type genes, collagen, and transforming growth factor-β
1
genes were upregulated and sustained in the noninfarcted area of WT hearts. In contrast, they were rapidly downregulated to basal levels at 4 weeks after MI in that of KO hearts.

Conclusions
—These results indicate that AT
1A
signals play a pivotal role in the progression of LV remodeling after MI, resulting in overt heart failure.
Rate- and Site-Dependent Effects of Propafenone, Dofetilide, and the New
I
Ks
-Blocking Agent Chromanol 293b on Individual Muscle Layers of the Intact Canine Heart
Authors: Bauer Alexander , Becker Ruediger , Freigang Kirsten D. , Senges Julia C. , Voss Frederik , Hansen Alexander , Müller Matthias , Lang Hans Jochen , Gerlach Uwe , Busch Andreas , Kraft Patricia , Kübler Wolfgang , Schöls Wolfgang
Published: June 2012

Background
—Recent in vitro studies have demonstrated regional differences in electrophysiological properties of individual left ventricular muscle layers. Controversy exists on the relevance of these findings for the situation in vivo. Thus, this study was designed to determine whether the in vivo canine heart exhibits regional differences in left ventricular refractoriness and in the susceptibility to sodium and potassium channel blockers.

Methods and Results
—In 16 dogs, 36 needle electrodes (12 mm long, 4 bipolar electrodes, interelectrode distance 2.5 mm) were inserted into the left ventricular wall. By use of a computerized multiplexer-mapping system, the spread of activation in epicardial, endocardial, and midmyocardial muscle was reconstructed during ventricular pacing at 300- and 850-ms basic cycle length (BCL). Effective refractory periods (ERPs) were determined at baseline and after application of propafenone (2 mg/kg), dofetilide (30 μg/kg), or chromanol 293b (10 mg/kg) by the extrastimulus technique (BCL 300 and 850 ms). At baseline, activation patterns and ERPs were uniform in all muscle layers. Propafenone homogeneously decreased conduction velocity and moderately prolonged ERPs without any regional differences. Dofetilide and chromanol 293b did not affect the spread of activation. Dofetilide exhibited reverse use-dependent effects on ERP, still preserving transmural homogeneity of refractoriness. Chromanol 293b led to a regionally uniform but more pronounced increase in local ERPs at faster than at slower pacing rates.

Conclusions
—At the heart rates applied, the in vivo canine heart does not exhibit regional differences in electrophysiological properties. Given the homogeneity of antiarrhythmic drug effects, induction of local gradients of refractoriness is obviously not a common mechanism of proarrhythmia in normal hearts.
Nocturnal Continuous Positive Airway Pressure Decreases Daytime Sympathetic Traffic in Obstructive Sleep Apnea
Authors: Narkiewicz Krzysztof , Kato Masahiko , Phillips Bradley G. , Pesek Catherine A. , Davison Diane E. , Somers Virend K.
Published: June 2012

Background
—Patients with obstructive sleep apnea (OSA) have high levels of muscle sympathetic nerve activity (MSNA). We tested the hypothesis that long-term continuous positive airway pressure (CPAP) treatment will decrease MSNA in OSA patients.

Methods and Results
—We measured blood pressure, heart rate, and MSNA in 11 normotensive, otherwise healthy patients with OSA who were treated with CPAP. The measurements were obtained at baseline and after 1 month, 6 months, and 1 year of CPAP treatment. These measurements were compared with those recorded in 9 otherwise healthy OSA patients who were not treated with CPAP for 1 year. In both untreated and treated patients, blood pressure and heart rate did not change over time. MSNA was similar during repeated measurements in the untreated group. By contrast, MSNA decreased significantly over time in patients treated with CPAP. This decrease was evident after both 6 months and 1 year of CPAP treatment (
P
=0.02 for both).

Conclusions
—CPAP treatment decreases muscle sympathetic traffic in patients with OSA. This effect of CPAP is evident only after an extended duration of therapy.
Profound Apoptosis-Mediated Regional Myocyte Loss and Compensatory Hypertrophy in Pigs With Hibernating Myocardium
Authors: Lim Hajin , Fallavollita James A. , Hard Robert , Kerr Christopher W. , Canty John M.
Published: June 2012

Background
—Myocyte apoptosis is seen in ischemic heart disease, but whether it can occur after reversible ischemia or independent of necrosis and replacement fibrosis is unknown.

Methods and Results
—Pigs were instrumented with a stenosis of the left anterior descending coronary artery to chronically reduce coronary flow reserve over a period of 3 months. At this time, there was viable dysfunctional myocardium having the physiological features of hibernating myocardium. Resting subendocardial perfusion was reduced to 0.65±0.08 (mean±SEM) mL · min
−1
· g
−1
in hibernating myocardium of instrumented pigs compared with 0.98±0.14 mL · min
−1
· g
−1
in myocardium of sham-operated pigs (
P
<0.05). There was a critical limitation in subendocardial flow during vasodilation to 0.78±0.20 mL · min
−1
· g
−1
in instrumented pigs versus 3.24±0.50 mL · min
−1
· g
−1
in sham-operated pigs (
P
<0.001). Histology revealed a regional reduction in myocyte nuclear density to 995±100 nuclei/mm
2
in hibernating myocardium from the instrumented group versus 1534±65 nuclei/mm
2
in myocardium from the sham-operated group (
P
<0.05), regional myocyte hypertrophy (myocyte volume per nucleus, 14 183±2594 in the instrumented group versus 9130±1301 μm
3
in the sham group;
P
<0.05), and minimal increases in connective tissue (5.8±0.9% in the instrumented group versus 3.0±0.2% in the sham group,
P
<0.05). Necrosis was not identified, but apoptosis was increased from 30±9 myocytes per 10
6
myocyte nuclei in myocardium from the sham group to 220±77 myocytes per 10
6
myocyte nuclei in hibernating myocardium (
P
<0.05).

Conclusions
—These findings indicate that reversible ischemia in an area of chronically reduced coronary flow reserve induces regional myocyte loss via an apoptotic mechanism. This may contribute to the progression of chronic coronary disease to heart failure and explain the lack of complete functional recovery after revascularization in hibernating myocardium.
Novel Modulator for Endothelial Adhesion Molecules
Authors: Ouchi Noriyuki , Kihara Shinji , Arita Yukio , Maeda Kazuhisa , Kuriyama Hiroshi , Okamoto Yoshihisa , Hotta Kikuko , Nishida Makoto , Takahashi Masahiko , Nakamura Tadashi , Yamashita Shizuya , Funahashi Tohru , Matsuzawa Yuji
Published: June 2012

Background
—Among the many adipocyte-derived endocrine factors, we recently found an adipocyte-specific secretory protein, adiponectin, which was decreased in obesity. Although obesity is associated with increased cardiovascular mortality and morbidity, the molecular basis for the link between obesity and vascular disease has not been fully clarified. The present study investigated whether adiponectin could modulate endothelial function and relate to coronary disease.

Methods and Results
—For the in vitro study, human aortic endothelial cells (HAECs) were preincubated for 18 hours with the indicated amount of adiponectin, then exposed to tumor necrosis factor-α (TNF-α) (10 U/mL) or vehicle for the times indicated. The adhesion of human monocytic cell line THP-1 cells to HAECs was determined by adhesion assay. The surface expression of vascular cell adhesion molecule-1 (VCAM-1), endothelial-leukocyte adhesion molecule-1 (E-selectin), and intracellular adhesion molecule-1 (ICAM-1) was measured by cell ELISA. Physiological concentrations of adiponectin dose-dependently inhibited TNF-α–induced THP-1 adhesion and expression of VCAM-1, E-selectin, and ICAM-1 on HAECs. For the in vivo study, the concentrations of adiponectin in human plasma were determined by a sandwich ELISA system that we recently developed. Plasma adiponectin concentrations were significantly lower in patients with coronary artery disease than those in age- and body mass index–adjusted control subjects.

Conclusions
—These observations suggest that adiponectin modulates endothelial inflammatory response and that the measurement of plasma adiponectin levels may be helpful in assessment of CAD risk.
Effects of Lovastatin and Warfarin on Early Carotid Atherosclerosis
Authors: Byington Robert P. , Evans Gregory W. , Espeland Mark A. , Applegate William B. , Hunninghake Donald B. , Probstfield Jeffrey , Furberg Curt D.
Published: June 2012

Background
—Few clinical trials have documented the efficacy of preventive treatment in asymptomatic women.

Methods and Results
—Lovastatin and minidose warfarin were evaluated in a factorially designed, placebo-controlled, randomized trial. The primary outcome was 3-year change in the mean maximum intimal-medial thickness of the carotid arteries as measured by B-mode ultrasonography. Participants (n=919) were randomized to 1 of 4 treatment groups: lovastatin alone, warfarin alone, lovastatin+warfarin combination, or a double-placebo group. Eligible participants were asymptomatic for cardiovascular disease, with evidence of early carotid atherosclerosis and moderately elevated LDL cholesterol level. Almost half (n=445) of the participants were women. To avoid confounding, 117 women taking estrogen were excluded from analysis. Both sexes experienced reductions in disease progression with lovastatin; there was no evidence of an overall sex×treatment interaction (
P
=0.72). When estimates of the sex-specific results were examined post hoc, women experienced disease regression to the greatest extent with the lovastatin+warfarin combination (
P
=0.02), although the women on lovastatin alone also had a reduction in progression (
P
=0.09). Men experienced the greatest reduction with lovastatin alone (
P
=0.02), although there is a suggestion that warfarin may also reduce progression to some extent.

Conclusions
—Lovastatin is beneficial in reducing disease progression in women and men. Warfarin has no effect in women, although it may reduce progression in men. In men, warfarin does not add to the benefit of lovastatin and has no advantage over lovastatin alone.
Effects of Oral Folic Acid Supplementation on Endothelial Function in Familial Hypercholesterolemia
Authors: Verhaar Marianne C. , Wever Robert M. F. , Kastelein John J. P. , van Loon Douwe , Milstien Sheldon , Koomans Hein A. , Rabelink Ton J.
Published: June 2012

Background
—Folates have been suggested to be of benefit in reducing cardiovascular risk. The present study was designed to examine whether oral folic acid supplementation could improve endothelial function as an intermediate end point for cardiovascular risk in patients with increased risk of atherosclerosis due to familial hypercholesterolemia (FH).

Methods and Results
—In a prospective, randomized, double-blind, placebo-controlled study with crossover design, we evaluated the effects of 4 weeks of treatment with oral folic acid (5 mg PO) on endothelial function in FH. In 20 FH patients, forearm vascular function was assessed at baseline, after 4 weeks of folic acid treatment, and after 4 weeks of placebo treatment by venous occlusion plethysmography, with serotonin and sodium nitroprusside used as endothelium-dependent and -independent vasodilators. In addition, we examined the vasoconstrictor response to the NO synthase inhibitor
N
G
-monomethyl-
l-
arginine to assess basal NO activity. In FH patients, folic acid supplementation restored the impaired endothelium-dependent vasodilation, whereas it did not significantly influence endothelium-independent vasodilation or basal forearm vasomotion. There was a trend toward improvement in basal NO activity.

Conclusions
—These data demonstrate that oral supplementation of folic acid can improve endothelial function in patients with increased risk of atherosclerotic disease due to hypercholesterolemia, without changes in plasma lipids.
Angiogenesis Gene Therapy
Authors: Rosengart Todd K. , Lee Leonard Y. , Patel Shailen R. , Sanborn Timothy A. , Parikh Manish , Bergman Geoffrey W. , Hachamovitch Rory , Szulc Massimiliano , Kligfield Paul D. , Okin Peter M. , Hahn Rebecca T. , Devereux Richard B. , Post Martin R. , Hackett Neil R. , Foster Taliba , Grasso Tina M. , Lesser Martin L. , Isom O. Wayne , Crystal Ronald G.
Published: June 2012

Background
—Therapeutic angiogenesis, a new experimental strategy for the treatment of vascular insufficiency, uses the administration of mediators known to induce vascular development in embryogenesis to induce neovascularization of ischemic adult tissues. This report summarizes a phase I clinical experience with a gene-therapy strategy that used an E1
−
E3
−
adenovirus (Ad) gene-transfer vector expressing human vascular endothelial growth factor (VEGF) 121 cDNA (Ad
GV
VEGF121.10) to induce therapeutic angiogenesis in the myocardium of individuals with clinically significant coronary artery disease.

Methods and Results
—Ad
GV
VEGF121.10 was administered to 21 individuals by direct myocardial injection into an area of reversible ischemia either as an adjunct to conventional coronary artery bypass grafting (group A, n=15) or as sole therapy via a minithoracotomy (group B, n=6). There was no evidence of systemic or cardiac-related adverse events related to vector administration. In both groups, coronary angiography and stress sestamibi scan assessment of wall motion 30 days after therapy suggested improvement in the area of vector administration. All patients reported improvement in angina class after therapy. In group B, in which gene transfer was the only therapy, treadmill exercise assessment suggested improvement in most individuals.

Conclusions
—The data are consistent with the concept that direct myocardial administration of Ad
GV
VEGF121.10 to individuals with clinically significant coronary artery disease appears to be well tolerated, and initiation of phase II evaluation of this therapy is warranted.
Lepirudin (Recombinant Hirudin) for Parenteral Anticoagulation in Patients With Heparin-Induced Thrombocytopenia
Authors: Greinacher Andreas , Janssens Uwe , Berg Gunther , Böck Markus , Kwasny Harald , Kemkes-Matthes Bettina , Eichler Petra , Völpel Heiko , Pötzsch Bernd , Luz Matthias
Published: June 2012

Background
—We prospectively investigated lepirudin for further parenteral anticoagulation in patients with heparin-induced thrombocytopenia (HIT).

Methods and Results
—Patients with confirmed HIT (n=112) received lepirudin according to need for 2 to 10 days (longer if necessary): A1, treatment: 0.4 mg/kg IV bolus, followed by 0.15 mg · kg
−1
· h
−1
intravenous infusion, n=65; A2, treatment in conjunction with thrombolysis: 0.2 mg/kg, followed by 0.10 mg · kg
−1
· h
−1
, n=4; and B, prophylaxis: 0.10 mg · kg
−1
· h
−1
, n=43. Outcomes from 95 eligible lepirudin-treated patients were compared with those of historical control patients (n=120). Complete laboratory response (activated partial thromboplastin time ratio >1.5 with ≤2 dose increases and platelet count normalization by day 10) was achieved in 65 lepirudin-treated patients (69.1%; 95% CI, 59.3% to 78.3%). At 2 weeks after cessation of lepirudin, 11 patients died (9.8%), 10 underwent limb amputation (8.9%), and 20 suffered a new thromboembolic complication (17.9%). The average combined event rate per patient-day decreased from 5.1% in the pretreatment period to 1.5% in the treatment period. Thirty-five days after HIT confirmation, fewer lepirudin-treated patients than historical control patients had experienced ≥1 outcome (cumulative incidence 30.9% versus 52.1%; relative risk [RR] 0.71;
P
=0.12, log-rank test). Bleeding events were more frequent in the lepirudin group than the historical control group (cumulative incidence at 35 days, 44.6% versus 27.2%; RR 2.57;
P
=0.0001, log-rank test). No difference was observed in bleeding events requiring transfusion (cumulative incidence at 35 days, 12.9% versus 9.1%; RR 1.66;
P
=0.23, log-rank test); no intracranial bleeding was observed in the lepirudin group.

Conclusions
—Lepirudin effectively prevents death, limb amputations, and new thromboembolic complications and has an acceptable safety profile in HIT patients. Treatment should be initiated as soon as possible if HIT is suspected.
Amiodarone Protects Cardiac Myocytes Against Oxidative Injury by its Free Radical Scavenging Action
Authors: Ide Tomomi , Tsutsui Hiroyuki , Kinugawa Shintaro , Utsumi Hideo , Takeshita Akira
Published: June 2012

Background
—Oxidative stress plays an important role in the pathophysiology of ischemic heart disease and heart failure, and antioxidants might be beneficial in the treatment of these patients. This study was performed to determine the scavenging effects of amiodarone on oxygen free radicals and its protective effects against oxygen radical-mediated injury in cardiac myocytes.

Methods and Results
—The formation of the radical spin adduct with hydroxy radical (·OH) in the presence of H
2
O
2
(10 mmol/L) and Fe
3+
-nitrilotriacetate (20 μmol/L) was monitored by electron paramagnetic resonance spectroscopy combined with a spin trapping agent, 5,5-dimethyl pyrroline-
N
-oxide (DMPO). Amiodarone decreased the intensity of the DMPO-OH signals in a dose-dependent manner (0.1 to 100 μmol/L), whereas other antiarrhythmia drugs such as disopyramide and atenolol had no such effects. Furthermore, amiodarone (10 μmol/L) protected intact adult canine cardiac myocytes against ·OH-mediated myocyte injury, as assessed by the degree of morphological change from rod shape to the irreversible hypercontracture state during the exposure of cells to H
2
O
2
and Fe
3+
in vitro.

Conclusions
—Amiodarone can protect cardiac myocytes against oxidative stress-mediated injury by directly scavenging oxygen free radicals. Antioxidant action of amiodarone might potentially contribute to the beneficial effects of this drug in the treatment of patients with ischemic heart disease and congestive heart failure.
Aminorex, Fenfluramine, and Chlorphentermine Are Serotonin Transporter Substrates
Authors: Rothman Richard B. , Ayestas Mario A. , Dersch Christina M. , Baumann Michael H.
Published: June 2012

Background
—Coadministration of phentermine and fenfluramine (phen/fen) effectively treats obesity and possibly addictive disorders. The association of fenfluramine and certain other anorexic agents with serious side effects, such as cardiac valvulopathy and primary pulmonary hypertension (PPH), limits the clinical utility of these drugs. Development of new medications that produce neurochemical effects like phen/fen without causing unwanted side effects would be a significant therapeutic breakthrough.

Methods and Results
—We tested the hypothesis that fenfluramine (and other anorexic agents) might increase the risk of PPH through interactions with serotonin (5-HT) transporters. Because 5-HT transporter proteins in the lung and brain are identical, we examined, in rat brain, the effects of selected drugs on 5-HT efflux in vivo and monoamine transporters in vitro as a generalized index of transporter function. Our data show that drugs known or suspected to increase the risk of PPH (eg, aminorex, fenfluramine, and chlorphentermine) are 5-HT transporter substrates, whereas drugs that have not been shown to increase the risk of PPH are less potent in this regard.

Conclusions
—We speculate that medications that are 5-HT transporter substrates get translocated into pulmonary cells where, depending on the degree of drug retention, their intrinsic drug toxicity, and individual susceptibility, PPH could develop as a response to high levels of these drugs or metabolites. Emerging evidence suggests that it is possible to develop transporter substrates devoid of adverse side effects. Such medications could have therapeutic application in the management of obesity, drug dependence, depression, and other disorders.
Influence of Balloon Pressure During Stent Placement in Native Coronary Arteries on Early and Late Angiographic and Clinical Outcome
Authors: Dirschinger Josef , Kastrati Adnan , Neumann Franz-Josef , Boekstegers Peter , Elezi Shpend , Mehilli Julinda , Schühlen Helmut , Pache Jürgen , Alt Eckhard , Blasini Rudolf , Steinbeck Gerhard , Schömig Albert
Published: June 2012

Background
—High-pressure dilatation is considered a better stent placement strategy, but this has not yet been proved by appropriately designed studies. The objective of this randomized trial was to assess the role of high-pressure dilatation in the early and late outcome of patients undergoing coronary stent placement.

Methods and Results
—Consecutive patients with coronary stent placement were randomly assigned to high- (15 to 20 atm, 468 patients) or low- (8 to 13 atm, 466 patients) balloon-pressure dilatation. The primary end point of the study was the event-free survival at 1 year. Secondary end points were the incidence of stent thrombosis at 30 days and angiographic restenosis (≥50% diameter stenosis) at 6 months. The incidence of stent thrombosis was 1.7% in the high-pressure and 1.9% in the low-pressure group (relative risk 0.89; 95% CI 0.30 to 2.56). During the first 30 days, although there was no significant difference in the incidence of Q-wave myocardial infarction, the incidence of non–Q-wave infarction was 6.4% in the high-pressure and 3.4% in the low-pressure group (relative risk 1.87; 95% CI 1.02 to 3.42). The restenosis rate was 30.4% in the high-pressure and 31.4% in the low-pressure group (relative risk 0.97; 95% CI 0.75 to 1.26). Event-free survival at 1 year was not significantly different between the groups, with 78.8% in high-pressure patients and 75.5% in patients assigned to low-pressure dilatation (hazard ratio 0.85; 95% CI 0.65 to 1.11).

Conclusions
—The systematic use of high-balloon-pressure inflation (15 to 20 atm) during coronary stent placement is not associated with any significant influence on the 1-year outcome of patients undergoing this intervention.
Reversal of Atrial Electrical Remodeling After Cardioversion of Persistent Atrial Fibrillation in Humans
Authors: Hobbs W. Julian C. , Fynn Simon , Todd Derick M. , Wolfson Peter , Galloway Mike , Garratt Clifford J.
Published: June 2012

Background
—Although atrial electrical remodeling has been studied extensively in animal models, the reversibility of this phenomenon after termination of clinical atrial fibrillation (AF) has not been demonstrated. We aimed to examine this important question of reversibility by using AF cycle length (AFCL) and coupling intervals of atrial premature beats after cardioversion as measures of atrial refractoriness.

Methods and Results
—We measured AFCL at the right atrial appendage and distal coronary sinus before attempting internal cardioversion in 39 patients with persistent AF. Patients were monitored by daily transtelephonic recordings after discharge and admitted rapidly for repeat internal cardioversion if there was spontaneous AF recurrence. Measurements of AFCL were repeated immediately before repeat cardioversions in the 17 patients who had recurrence of AF. There was an increase in AFCL from the initial cardioversion to that measured at the time of first AF recurrence at both the right atrial appendage (161±22 vs 167±26 ms,
P
=0.05) and distal coronary sinus (162±20 vs 168±22 ms,
P
=0.01) sites. The magnitude of increase in AFCL was positively correlated with duration of sinus rhythm before AF recurrence (
r=
0.524,
P
=0.001). Other measures of refractoriness (shortest coupling interval of atrial premature beats and directly measured refractory periods after cardioversion) also increased from initial to subsequent cardioversions.

Conclusions
—These findings demonstrate that changes in atrial electrophysiology associated with chronic AF in humans are reversible after cardioversion and that the extent of this reversal is dependent on the duration of sinus rhythm after cardioversion.
Construction and Functional Evaluation of a Single-Chain Antibody Fusion Protein With Fibrin Targeting and Thrombin Inhibition After Activation by Factor Xa
Authors: Peter Karlheinz , Graeber Justin , Kipriyanov Sergey , Zewe-Welschof Monika , Runge Marschall S. , Kübler Wolfgang , Little Melvyn , Bode Christoph
Published: June 2012

Background
—Recombinant technology was used to produce a new anticoagulant that is preferentially localized and active at the site of the clot.

Methods and Results
—The variable regions of the heavy and light chains of a fibrin-specific antibody were amplified by polymerase chain reaction (PCR) with hybridoma cDNA. To obtain a functional single-chain antibody (scFv), a linker region consisting of (Gly
4
Ser)
3
was introduced by overlap PCR. After the scFv clones were ligated with DNA encoding the pIII protein of the M13 phage, high-affinity clones were selected by 10 rounds of panning on the Bβ15-22 peptide of fibrin (β-peptide). Hirudin was genetically fused to the C-terminus of the variable region of the light chain. To release the functionally essential N-terminus of hirudin at the site of a blood clot, a factor Xa recognition site was introduced between scFv
59D8
and hirudin. The fusion protein was characterized by its size on SDS-PAGE (36 kDa), by Western blotting, by its cleavage into a 29-kDa (single chain alone) and 7-kDa (hirudin) fragment, by its binding to β-peptide, and by thrombin inhibition after Xa cleavage. Finally, the fusion protein inhibited appositional growth of whole blood clots in vitro more efficiently than native hirudin.

Conclusions
—A fusion protein was constructed that binds to a fibrin-specific epitope and inhibits thrombin after its activation by factor Xa. This recombinant anticoagulant effectively inhibits appositional clot growth in vitro. Its efficient and fast production at low cost should facilitate a large-scale evaluation to determine whether an effective localized antithrombin activity can be achieved without systemic bleeding complications.
Inhibition of Myosin Phosphatase by Upregulated Rho-Kinase Plays a Key Role for Coronary Artery Spasm in a Porcine Model With Interleukin-1β
Authors: Kandabashi Tadashi , Shimokawa Hiroaki , Miyata Kenji , Kunihiro Ikuko , Kawano Yoji , Fukata Yuko , Higo Taiki , Egashira Kensuke , Takahashi Shosuke , Kaibuchi Kozo , Takeshita Akira
Published: June 2012

Background
—We recently demonstrated that the Rho-kinase–mediated pathway plays an important role for coronary artery spasm in our porcine model with interleukin-1β (IL-1β). In this study, we examined whether or not Rho-kinase is upregulated at the spastic site and if so, how it induces vascular smooth muscle hypercontraction.

Methods and Results
—Segments of the left porcine coronary artery were chronically treated from the adventitia with IL-1β–bound microbeads. Two weeks after the operation, as reported previously, intracoronary serotonin repeatedly induced coronary hypercontractions at the IL-1β–treated site both in vivo and in vitro, which were markedly inhibited by Y-27632, one of the specific inhibitors of Rho-kinase. Reverse transcription–polymerase chain reaction analysis demonstrated that the expression of Rho-kinase mRNA was significantly increased in the spastic compared with the control segment. Western blot analysis showed that during the serotonin-induced contractions, the extent of phosphorylation of the myosin-binding subunit of myosin phosphatase (MBS), one of the major substrates of Rho-kinase, was significantly greater in the spastic than in the control segment and that the increase in MBS phosphorylations was also markedly inhibited by Y-27632. There was a highly significant correlation between the extent of MBS phosphorylations and that of contractions.

Conclusions
—These results indicate that Rho-kinase is upregulated at the spastic site and plays a key role in inducing vascular smooth muscle hypercontraction by inhibiting myosin phosphatase through the phosphorylation of MBS in our porcine model.
Ventricular Defibrillation With Triphasic Waveforms
Authors: Huang Jian , KenKnight Bruce H. , Rollins Dennis L. , Smith William M. , Ideker Raymond E.
Published: June 2012

Background
—It has been reported that triphasic defibrillation waveforms cause less myocardial injury than biphasic waveforms. This study compared the defibrillation thresholds (DFTs) of triphasic and biphasic waveforms.

Methods and Results
—DFTs were determined for a transvenous lead system and a 300-μF-capacitor defibrillator. In 8 pigs (group 1), DFTs were determined for 5 triphasic waveforms with tilts of 80%, 83%, and 86% and for 1 biphasic waveform. DFTs were determined in another 8 pigs (group 2) for 2 triphasic and 4 biphasic waveforms with tilts of 43%, 49%, and 56%. In both groups, a biphasic waveform from a 140-μF-capacitor defibrillator was also evaluated, and both shock polarities were tested for each waveform. In group 1, with the 300-μF-capacitor defibrillator, the leading-edge voltage and energy stored at DFT were significantly lower for triphasic waveforms with phase-duration ratios of 50/33/17 and an anode at the right ventricular electrode for phase 1 than for biphasic waveforms (
P
<0.001). In group 2, the stored energy of triphasic waveforms with 56% and 49% tilt was significantly lower than that of biphasic waveforms with the same tilts for anodal but not cathodal phase 1 at the right ventricular electrode. Electrode polarity significantly affected the DFT of triphasic waveforms for both studies.

Conclusions
—Some 80% tilt triphasic waveforms defibrillate more efficiently than biphasic waveforms with a 300-μF-capacitor defibrillator. The triphasic waveforms for both groups were not superior to 140-μF-capacitor biphasic waveforms. The efficacy of triphasic waveforms depends on phase durations and electrode polarity.
The Apolipoprotein ε4 Allele Determines Prognosis and the Effect on Prognosis of Simvastatin in Survivors of Myocardial Infarction
Authors: Gerdes Lars Ulrik , Gerdes Christian , Kervinen Kari , Savolainen Markku , Klausen Ib Christian , Hansen Peter Steen , Kesäniemi Y. Antero , Færgeman Ole
Published: June 2012

Background
—Carriers of the ε4 allele of the apolipoprotein E gene are at a higher risk of coronary heart disease than individuals with other genotypes. We examined whether the risk of death or a major coronary event in survivors of myocardial infarction depended on apolipoprotein E genotype and whether the benefits of treatment with simvastatin differed between genotypes.

Methods and Results
—Cox proportional hazards models were used to analyze 5.5 years of follow-up data from 966 Danish and Finnish myocardial infarction survivors enrolled in the Scandinavian Simvastatin Survival Study. A total of 16% of the 166 ε4 carriers in the placebo group died compared with 9% of the 312 patients without the allele, which corresponds to a mortality risk ratio of 1.8 (95% confidence interval, 1.1 to 3.1). The risk ratio was unaffected by considerations of sex, age, concurrent angina, diabetes, smoking, and serum lipids in multivariate analyses. Simvastatin treatment reduced the mortality risk to 0.33 (95% confidence interval, 0.16 to 0.69) in ε4 carriers and to 0.66 (95% confidence interval, 0.35 to 1.24) in other patients (
P
=0.23 for treatment by genotype interaction). Apolipoprotein E genotype did not predict the risk of a major coronary event. Baseline serum levels of lipoprotein(a) also predicted mortality risk and could be combined with ε4-carrier status to define 3 groups of patients with different prognoses and benefits from treatment.

Conclusions
—Myocardial infarction survivors with the ε4 allele have a nearly 2-fold increased risk of dying compared with other patients, and the excess mortality can be abolished by treatment with simvastatin.
A Newly Created Splice Donor Site in Exon 25 of the MyBP-C Gene Is Responsible for Inherited Hypertrophic Cardiomyopathy With Incomplete Disease Penetrance
Authors: Moolman Johannes A. , Reith Sebastian , Uhl Kerstin , Bailey Sonja , Gautel Mathias , Jeschke Brigitte , Fischer Christine , Ochs Julia , McKenna William J. , Klues Heinz , Vosberg Hans-Peter
Published: June 2012

Background
—Hypertrophic cardiomyopathy is a myocardial disorder resulting from inherited sarcomeric dysfunction. We report a mutation in the myosin-binding protein-C (MyBP-C) gene, its clinical consequences in a large family, and myocardial tissue findings that may provide insight into the mechanism of disease.

Methods and Results
—History and clinical status (examination, ECG, and echocardiography) were assessed in 49 members of a multigeneration family. Linkage analysis implicated the MyBP-C gene on chromosome 11. Myocardial mRNA, genomic MyBP-C DNA, and the myocardial proteins of patients and healthy relatives were analyzed. A single guanine nucleotide insertion in exon 25 of the MyBP-C gene resulted in the loss of 40 bases in abnormally processed mRNA. A 30-kDa truncation at the C-terminus of the protein was predicted, but a polypeptide of the expected size (≈95 kDa) was not detected by immunoblot testing. The disease phenotype in this family was characterized in detail: only 10 of 27 gene carriers fulfilled diagnostic criteria. Five carriers showed borderline hypertrophic cardiomyopathy, and 12 carriers were asymptomatic, with normal ECG and echocardiograms. The age of onset in symptomatic patients was late (29 to 68 years). In 2 patients, outflow obstruction required surgery. Two family members experienced premature sudden cardiac death, but survival at 50 years was 95%.

Conclusions
—Penetrance of this mutation was incomplete and age-dependent. The large number of asymptomatic carriers and the good prognosis support the interpretation of benign disease.
IL-8 Is an Angiogenic Factor in Human Coronary Atherectomy Tissue
Authors: Simonini Americo , Moscucci Mauro , Muller David W. M. , Bates Eric R. , Pagani Francis D. , Burdick Marie D. , Strieter Robert M.
Published: June 2012

Background
—Interleukin-8 (IL-8), a CXC chemokine that induces the migration and proliferation of endothelial cells and smooth muscle cells, is a potent angiogenic factor that may play a role in atherosclerosis. Previously, IL-8 has been reported in atherosclerotic lesions and circulating macrophages from patients with atherosclerosis. Therefore, we sought to determine whether IL-8 plays a role in mediating angiogenic activity in atherosclerosis.

Methods and Results
—Homogenates from 16 patients undergoing directional coronary atherectomy (DCA) and control samples from the internal mammary artery (IMA) of 7 patients undergoing bypass graft surgery were assessed for IL-8 content by specific ELISA, immunohistochemistry, and in situ hybridization for IL-8 mRNA. The contribution of IL-8 to net angiogenic activity was assessed using the rat cornea micropocket assay and cultured cells. IL-8 expression was significantly elevated in DCA samples compared with IMA samples (1.71±0.6 versus 0.05±0.03 ng/mg of total protein;
P
<0.01). Positive immunolocalization of IL-8 was found exclusively in DCA tissue sections, and it correlated with the presence of factor VIII–related antigen. In situ reverse transcriptase polymerase chain reaction revealed the expression of IL-8 mRNA in DCA tissue. Corneal neovascular response, defined by ingrowth of capillary sprouts toward the implant, was markedly positive with DCA pellets, but no constitutive vessel ingrowth was seen with IMA specimens. Neutralizing IL-8 attenuated both the in vivo corneal neovascular response and the in vitro proliferation of cultured cells.

Conclusions
—The results suggest that, in human coronary atherosclerosis, IL-8 is an important mediator of angiogenesis and may contribute to plaque formation via its angiogenic properties.
Abnormalities of Cardiac Sympathetic Innervation in Arrhythmogenic Right Ventricular Cardiomyopathy
Authors: Wichter Thomas , Schäfers Michael , Rhodes Christopher G. , Borggrefe Martin , Lerch Hartmut , Lammertsma Adriaan A. , Hermansen Flemming , Schober Otmar , Breithardt Günter , Camici Paolo G.
Published: June 2012

Background
—The frequent provocation of ventricular tachycardia by stress or catecholamines and the efficacy of antiarrhythmic drugs with antiadrenergic properties suggest an involvement of the cardiac adrenergic system in arrhythmogenesis in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Previous studies demonstrated abnormalities of the presynaptic uptake-1 assessed by
123
I-MIBG–single-photon emission computed tomography.

Methods and Results
—This study investigated neuronal reuptake of norepinephrine (uptake-1) and β-adrenergic receptor density in 8 patients with ARVC and 29 age-matched control subjects. All subjects underwent positron emission tomography with the volume of distribution (V
d
) of [
11
C]hydroxyephedrine (
11
C-HED) used to assess presynaptic norepinephrine reuptake, the maximum binding capacity (B
max
) of [
11
C]CGP-12177 (
11
C-CGP-12177) to assess postsynaptic β-adrenergic receptor density, and [
15
O]H
2
O for quantification of myocardial blood flow. Patients with ARVC demonstrated a highly significant global reduction in postsynaptic β-adrenergic receptor density compared with that in control subjects (B
max
of
11
C-CGP-12177: 5.9±1.3 vs 10.2±2.9 pmol/g tissue,
P
<0.0007), whereas the presynaptic uptake-1 tended toward reduction only (V
d
of
11
C-HED: 59.1±25.2 vs 71.0±18.8 mL/g tissue, NS). There were no differences in myocardial blood flow between the groups, and plasma norepinephrine was within normal limits in patients and control subjects.

Conclusions
—The findings demonstrate a significant reduction of myocardial β-adrenergic receptor density in patients with ARVC. This may result from a secondary downregulation after increased local synaptic norepinephrine levels caused by increased firing rates of the efferent neurons or as the result of impaired presynaptic catecholamine reuptake. These findings give new insights into the pathophysiology of arrhythmogenesis in ARVC, with potential impact on diagnostic evaluation and therapeutic management.
Inhibition of Transplant Vasculopathy in a Rat Aortic Allograft Model After Infusion of Anti-Inflammatory Viral Serpin
Authors: Miller Leslie W. , Dai Erbin , Nash Piers , Liu Liying , Icton Carolyn , Klironomos Dennis , Fan Lilly , Nation Patric N. , Zhong Robert , McFadden Grant , Lucas Alexandra
Published: June 2012

Background
—Transplant vasculopathy remains a difficult therapeutic problem, resulting in the majority of late cardiac graft losses. This chronic vascular disease is thought to be triggered by alloantigen-dependent and alloantigen-independent inflammatory factors. Despite improved 1-year survival, the incidence of transplant vasculopathy has not improved with current immunosuppressive protocols. Highly effective strategies have evolved in the large DNA viruses that shield infecting viruses from host inflammatory responses. Serp-1 is a secreted myxoma virus anti-inflammatory serine proteinase inhibitor. Serp-1 inhibits plasminogen activators in a manner similar to plasminogen activator inhibitor (PAI-1), a vascular protein that plays a pivotal regulatory role in vascular wound healing. In this study, we tested the ability of purified Serp-1 protein to ameliorate posttransplant vasculopathy after rat aortic allograft surgery.

Methods and Results
—Serp-1 protein or controls were infused into 98 rats immediately after segmental aortic allograft transplantation. After either late (28 days, 64 rats) or early (12 to 48 hours, 24 rats) follow-up, transplanted aortic segments were harvested for morphological and immunohistochemical analysis. Significant reductions in intimal plaque growth (
P
<0.002) and mononuclear cell invasion (
P
<0.033) were detected after Serp-1 infusion at nanogram doses. Serp-1 reduced early macrophage (
P
<0.0016) and nonspecific lymphocyte (
P
<0.0179) invasion into medial and adventitial layers and inhibited associated depletion of medial smooth muscle cells (
P
<0.0006).

Conclusions
—Infusion of a viral anti-inflammatory serpin, Serp-1, significantly reduces early inflammatory responses and later luminal occlusion in a rat aortic allograft model.
Identification of Coronary Thrombus With a IIb/IIIa Platelet Inhibitor Radiopharmaceutical, Technetium-99m DMP-444
Authors: Mitchel Joseph , Waters David , Lai Tianjie , White Michael , Alberghini Tod , Salloum Ahmad , Knibbs David , Li Dadong , Heller Gary V.
Published: June 2012

Background
—A diagnostic test that could distinguish between stable and unstable coronary atherosclerotic plaques would be useful. We tested the ability of a new glycoprotein IIb/IIIa platelet inhibitor DMP-444, labeled with technetium (Tc)-99 m, to identify platelet-rich thrombus by nuclear imaging in a canine model.

Methods and Results
—Combinations of a flow-limiting stenosis and 0 to 15 minutes of endothelial electrical stimulation at a site in the left anterior descending coronary artery were used to induce varying amounts of thrombus formation. In 10 animals with markedly positive nuclear images after the injection of Tc-99m DMP-444, the presence of platelet-rich thrombus was confirmed postmortem by gross appearance, high nuclear counts, and abundant platelets on electron microscopy. The 10 animals with negative images had lower counts, smaller thrombus weights (
P
<0.05 for each), and fewer platelets by electron microscopy.

Conclusions
—Activated platelets participating in acute thrombus formation can be accurately detected by nuclear imaging using Tc-99 m DMP-444.
Identification of Patients Most Likely to Benefit From Implantable Cardioverter-Defibrillator Therapy
Authors: Sheldon Robert , Connolly Stuart , Krahn Andrew , Roberts Robin , Gent Michael , Gardner Martin
Published: June 2012

Background
—Patients with resuscitated ventricular tachyarrhythmias (ventricular tachycardia/ventricular fibrillation) benefit from implantable cardioverter-defibrillators (ICDs) compared with medical therapy. We hypothesized that the patients who benefit most from an ICD are those at greatest risk of death.

Methods and Results
—In the Canadian Implantable Defibrillator Study (CIDS), 659 patients with resuscitated ventricular tachyarrhythmias were randomly assigned to receive an ICD or amiodarone and were then followed for a mean of 3 years. There were 98 and 83 deaths in the amiodarone and ICD groups, respectively. We used multivariate Cox analysis to assess the impact of baseline parameters on the mortality in the amiodarone group. Reduced left ventricular ejection fraction, advanced age, and poor NYHA status identified high-risk patients (
P
=0.0001 to 0.0009). Quartiles of risk were constructed, and the mortality reduction associated with ICD treatment in each quartile was assessed. There was a significant interaction between risk quartile and the ICD treatment effect (
P
=0.011). In the highest risk quartile, there was a 50% relative risk reduction (95% CI 21% to 68%) of death in the ICD group, whereas in the 3 lower quartiles, there was no benefit. Patients who are most likely to benefit from an ICD can be identified with a simple risk score (≥2 of the following factors: age ≥70 years, left ventricular ejection fraction ≤35%, and NYHA class III or IV). Thirteen of 15 deaths that were prevented by the ICD occurred in patients with ≥2 risk factors.

Conclusions
—In CIDS, patients at highest risk of death benefited most from ICD therapy. These can be identified easily on the basis of age, poor ventricular function, and poor functional status.
Evolution of the Volume-Outcome Relation for Hospitals Performing Coronary Angioplasty
Authors: Ho Vivian
Published: June 2012

Background
—Hospitals performing more surgical procedures tend to yield better outcomes. This study examines the evolution of this volume-outcome relation over time.

Methods and Results
—The relation between the number of percutaneous transluminal coronary angioplasty (PTCA) procedures performed at hospitals (volume) and in-hospital bypass surgery and death for 353 488 patients treated in California between 1984 and 1996 was examined. Descriptive statistics and logistic regression were used to compare outcomes for 3 periods: 1984 to 1987, 1988 to 1992, and 1993 to 1996. The in-hospital mortality rate was 2.5% for hospitals performing <200 PTCA procedures per year but only 1.3% for hospitals performing >400 procedures per year in 1984 to 1987. By 1993 to 1996, mortality rates in these 2 volume categories narrowed to 1.7% and 1.3%, respectively. Bypass surgery rates also narrowed and fell in low-volume (<200 procedures) versus high-volume (>400 procedures) hospitals from 12.4% versus 6.9% in 1984 to 1987 to 4.6% versus 3.3% in 1993 to 1996. In a logistic regression, PTCA procedures significantly predicted in-hospital mortality and bypass surgery rates in all 3 time periods. However, coefficient estimates indicate that improvements over time in outcomes for hospitals performing <200 procedures were comparable to the predicted benefits of increasing volume above 400 procedures within time periods.

Conclusions
—Over time, the disparity in outcomes between low- and high-volume hospitals has narrowed, and outcomes have improved significantly for all hospitals. Given these improvements, lower minimum volume standards may be advisable in less populated areas, where the alternative is no angioplasty at all.