bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 692: Therapeutic Inhibition of miR-33 Does Not Promote Obesity, Insulin Resistance or Hepatic Lipid Accumulation
Authors: Karunakaran Denuja , Geoffrion Michéle , Barrett Danyk , Harper Mary-Ellen , Esau Christine C , Rayner Katey J
Published: July 2021

Inhibition of miR-33, a critical post-transcriptional regulator of cholesterol homeostasis, prevents atherosclerosis progression both dependently and independently of its effects on circulating HDL levels. However, recent studies suggest that genetic deletion or inhibition of miR-33 may adversely affect metrics of insulin resistance, lipid metabolism and hepatic steatosis. Given the therapeutic interest in miR-33 inhibitors for treating atherosclerosis, we sought to determine the effects of long-term pharmacological inhibition of miR33 in a mouse model of diet-induced obesity (DIO). Results: C57BL6/J mice were fed a high-fat diet in conjunction with anti-miR therapy (10mg/kg of control anti-miR or anti-miR33) for 20 weeks. There was significant but equivalent weight gain in all 3 groups. While anti-miR33 therapy increased total plasma cholesterol compared to control anti-miR treated mice (p≤0.01), there was no differences relative to PBS treated mice. Anti-miR33 treatment also resulted in a marked decrease in serum triglycerides relative to control anti-miR (29% decrease, p≤0.05) but once again not compared to PBS treated mice. Metrics of insulin resistance (GTT, ITT) were not altered in anti-miR33 treated mice relative to controls. Interestingly, indirect calorimetric measurements demonstrated that anti-miR33 treated mice had reduced respiratory exchange ratios (RER) compared to both control anti-miR and PBS treated mice (18% decrease, p≤0.05), suggesting an increase in fatty acid versus carbohydrate utilization in anti-miR33 treated mice. In addition, hepatic protein expression of known miR-33 target gene ABCA1 was de-repressed upon miR-33 inhibition, indicating that miR-33 was efficiently inhibited in this model. In contrast, putative miR-33 target gene SREBP-1 protein expression was not altered, nor were SREBP-1 downstream target genes FASN and ACC. Finally, anti-miR33 treated mice did not accumulate more lipids in their livers relative to control. In conclusion, we show in a DIO model that therapeutic silencing of miR-33 does not promote hepatic steatosis nor does it increase metrics of insulin resistance, suggesting that pharmacological inhibition of miR-33 may be a safe therapeutic for the treatment of atherosclerosis.
Abstract 697: Protein Sumoylation in the Adipocyte Modulates Inflammatory Responses, Diabetes and Cardiovascular Disease
Authors: Min Wang , Shao Lan , Zhou Jenny Huanjiao , Huang Qunhua
Published: July 2021

Adipocyte dysfunction is highly correlated with the development of diabetes. Protein SUMOylation has emerged as important regulatory mechanisms for protein function. In this study, we show that mice with a genetic deletion of the SUMO-specific protease SENP1 gene in adipocytes (SENP1-apKO) develop a type 1 diabetes mellitus (T1DM), including hyperglycemia, glucose intolerance, and increased circulating diabetic markers insulin autoantibody, C-reactive protein and beta-hydroxybutyrate with normal lipid profiles. The pancreases of SENP1-apKO mice exhibit increased infiltration of T cells and inflammation-induced β-cell apoptosis. Detailed analyses indicate that proinflammatory cytokines produced by pancreatic adipocytes in SENP1-apKO mice precedes the onset of T1DM phenotype. Mechanistic studies show that NEMO, the NF-κB essential molecule, is a major target of SENP1 in the adipose tissues. SENP1 deletion in pancreatic adipocytes enhances NEMO SUMOylation at lysine 277/309, augmenting NF-κB activity, cytokine production and pancreatic inflammation. More importantly, NF-κB inhibitor could inhibit pre-diabetic cytokine production, beta cell damages and T1DM phenotype in SENP1-apKO mice. Our study has uncovered a novel mechanism for the onset and progression of T1DM associated with adipocyte dysfunction. The SENP-apKO mice also develop other cardiovascular disease phenotype and we will discuss potential mechanisms.
Abstract 698: Increases Reticulated Platelets due to Enhanced Proliferation and Expansion of Bone Marrow Megakaryocyte Progenitors Accelerates Atherosclerosis in Diabetes
Authors: Kraakman Michael J , Dragoljevic Dragana , Hanssen Nordin M , Jandeleit-Dahm Karin , Kile Benjamin T , Josefsson Emma , Febbraio Mark A , Chin-Dusting Jaye P , Cooper Mark E , Nagareddy Prabhakara R , Goldberg Ira J , Murphy Andrew J
Published: July 2021

Diabetes (type 1 & 2) is a major risk factor for cardiovascular disease which represents the major cause of mortality in this group. Patients with diabetes present with reticulated thrombocytosis (increased immature platelets), which lower the efficacy of current anti-platelet therapies. We hypothesized that the reticulated thrombocytosis observed in people with diabetes plays an important role in atherogenesis. Thus, we investigated the mechanisms contributing to increased reticulated platelets in diabetes. Streptozotocin induced diabetic mice had significantly higher level (2-fold) of reticulated platelets. This was paralleled by an increase in the population of megakaryocyte progenitors (MkPs) and megakaryocytes in the bone marrow (BM). Diabetes caused an increase in circulating thrombopoietin (TPO) without altering the expression of the TPO receptor (c-MPL) on any of the BM progenitor cells or circulating platelets. TPO expression is generally upregulated by Kupffer cell derived interleukin-6 (IL-6). We found more Kupffer cells in the liver of diabetic mice which expressed higher levels of cell surface RAGE (Receptor for Advanced Glycated End-products) and produced more IL-6. Depletion of Kupffer cells using clodronate liposomes normalized the levels of total and reticulated platelets along with MkPs in the BM. Rage-/- BM transplantation (BMT) into mice that were then made diabetic were protected from diabetes-induced thrombocytosis and MkP expansion. Kupffer cells from diabetic Rage-/- BMT mice failed to express IL-6 and plasma TPO levels remained similar to the non-diabetic mice. IL-6-/- BMT mice were also protected from diabetes-induced thrombocytosis. Together, we identified a role for RAGE in the liver Kupffer cells of diabetic mice that triggers IL-6 expression, which in-turn promotes TPO production. TPO then enhances proliferation and expansion of MkPs in the BM, resulting in an increase in the abundance of reticulated platelets. Using BM from a genetic model (Bcl-xPlt20) of low platelets transplanted into Ldlr+/- mice we found that lower circulating platelets resulted in smaller atherosclerotic lesions. Our data suggests that increased platelet production contributes to accelerated atherogenesis in diabetes.
Effect of Accessory Pulmonary Blood Flow on Survival After the Bidirectional Glenn Procedure
Authors: Mainwaring Richard D. , Lamberti John J. , Uzark Karen , Spicer Robert L. , Cocalis Mark W. , Moore John W.
Published: July 2021

Background
—The bidirectional Glenn procedure (BDG) is used in the staged surgical management of patients with a functional single ventricle. Controversy exists regarding whether accessory pulmonary blood flow (APBF) should be left at the time of BDG to augment systemic saturation or be eliminated to reduce volume load of the ventricle. The present study was a retrospective review of patients undergoing BDG that was conducted to assess the influence of APBF on survival rates.

Methods and Results
—From 1986 through 1998, 149 patients have undergone BDG at our institution. Ninety-three patients had elimination of all sources of APBF, whereas 56 patients had either a shunt or a patent right ventricular outflow tract intentionally left in place to augment the pulmonary blood flow provided by the BDG. The operative mortality rate was 2.2% without APBF and 5.4% with APBF. The late mortality rate was 4.4% without APBF and 15.1% with APBF. Actuarial analysis demonstrates a divergence of the Kaplan-Meier curves in favor of patients in whom APBF was eliminated (
P
<0.02). One hundred seven patients have subsequently undergone completion of their Fontan operation, so the actuarial analysis includes the operative risk of this second operation.

Conclusions
—The results suggest that the elimination of APBF at the time of BDG may confer a long-term advantage for patients with a functional single ventricle.
Quantitative Changes In T-Cell Populations After Left Ventricular Assist Device Implantation
Authors: Ankersmit Hendrik-Jan , Edwards Niloo M. , Schuster Michael , John Ranjit , Kocher Alfred , Rose Eric A. , Oz Mehmet , Itescu Silviu
Published: July 2021

Background
—Left ventricular assist devices (LVADs) are currently being evaluated as permanent therapy for end-stage heart failure. Because life-threatening infections limit successful long-term device implantation, we investigated the relationship between quantitative T-cell defects in LVAD recipients and CD95-mediated T-cell apoptosis.

Methods and Results
—Immunological studies were performed in NYHA class IV patients awaiting cardiac transplantation who received either a TCI Heartmate left ventricular assist device (LVAD) or medical management. Fluorochrome-labeled Mabs were used in T-cell phenotypic analyses. T-cell apoptosis was measured by annexin V binding of T cells cultured in medium for 24 hours. Circulating serum levels of soluble CD95 were measured by ELISA. LVAD recipients had a relative lymphopenia and reduction in CD4 T-cell levels compared with NYHA class IV heart failure controls. These observations were confirmed in a longitudinal study in LVAD recipients, which showed that device implantation was accompanied by progressive and sustained reductions in circulating CD4 T-cell levels. These abnormalities in LVAD recipients were accompanied by increased levels of circulating soluble CD95 and by excessive CD4 and CD8 T-cell apoptosis. Susceptibility to induction of apoptosis was >2-fold greater for CD4 T cells than for CD8 T cells.

Conclusions
—These results suggest that the reduction in CD4 T-cell levels accompanying LVAD implantation is a consequence of an augmented pathway of CD95-mediated apoptosis. The clinical consequences of these abnormalities may include increased prevalence of systemic infections.
Toward the Best Treatment for Uncomplicated Patients With Type B Acute Aortic Dissection
Authors: Marui Akira , Mochizuki Takaaki , Mitsui Norimasa , Koyama Tadaaki , Kimura Fumiko , Horibe Mayumi
Published: July 2021

Background
—In the treatment of type B acute aortic dissection without complications, better results are obtained if surgery is performed before enlargement of the aorta in patients who are predicted to show aortic enlargement and if drug-based treatment is continued for patients who are predicted to show no enlargement. The purpose of this study was to predict the acute-phase factors that may affect chronic-phase aortic enlargement by studying chronic-phase enlargement of dissections in patients without complications during the acute phase.

Methods and Results
—In 101 patients with type B acute dissection who had no complications, univariate and multivariate factor analyses were performed to determine the predictors for chronic-phase enlargement (≥60 mm) of the dissected aorta. The independent predominant predictors for aortic enlargement in the chronic phase were a maximum aortic diameter of ≥40 mm and a patent false lumen during the acute phase. The values of actuarial freedom from aortic enlargement for the patients with a maximum aortic diameter of 40 mm and a patent false lumen at 1, 5, and 10 years were 43%, 33%, and 22%, respectively, whereas in patients with a maximum aortic diameter of <40 mm and a closed false lumen, the values were 97%, 94%, and 84%, respectively.

Conclusions
—These results suggest that patients with type B acute aortic dissection who show a maximum aortic diameter of ≥40 mm and a patent false lumen should undergo surgery earlier during the chronic phase before enlargement of aorta, whereas patients with a maximum aortic diameter of <40 mm and a closed false lumen should continue to receive hypotensive therapy.
Preconditioning by Mitochondrial ATP-Sensitive Potassium Channel Openers
Authors: Kevelaitis Egidijus , Oubénaïssa Abdeslam , Peynet Jacqueline , Mouas Christian , Menasché Philippe
Published: July 2021

Background
—Recent studies have implicated mitochondrial ATP-sensitive potassium (K
ATP
) channels in the cardioprotective effects of ischemic preconditioning. The present study used a model of prolonged cold heart storage to assess whether the mitochondrial K
ATP
opener diazoxide could reproduce the protection conferred by ischemic preconditioning.

Methods and Results
—Fifty-four isolated rat hearts were arrested with and stored in Celsior at 4°C for 10 hours before a 2-hour reperfusion. They were divided into 5 groups. Group 1 hearts served as controls. In group 2, hearts were preconditioned by two 5-minute episodes of global ischemia, each separated by 5 minutes of reperfusion before arrest. In group 3, hearts received a 15-minute infusion of the mitochondrial K
ATP
opener diazoxide (30 μmol/L) followed by 5 minutes of washout before arrest. In groups 4 and 5, hearts underwent a protocol similar to that used in groups 2 and 3, respectively, except that the preconditioning was preceded by a 10-minute infusion of the mitochondrial K
ATP
blocker 5-hydroxydecanoate (5-HD, 100 μmol/L). Both ischemic and diazoxide preconditioning provided a similar degree of cardioprotection demonstrated by a significantly better preservation of left ventricular compliance, reduced leakage of creatine kinase, and smaller degree of myocardial edema compared with control hearts. These beneficial effects were abolished by 5-HD pretreatment. Postischemic left ventricular contractility and endothelium-dependent coronary response to 5-hydroxytryptamine and acetylcholine were not different among groups. However, the endothelium-independent vasodilatory postischemic response to papaverine was better preserved after ischemic and diazoxide preconditioning than in the other groups.

Conclusions
—These data support the concept that the cardioprotective effects of ischemic preconditioning can be duplicated by a mitochondrial K
ATP
opener and suggest that activation of these channels could be an effective means of improving the preservation of globally ischemic cold-stored hearts, as occurs during cardiac transplantation.
Oxidative Stress Induces NF-κB Nuclear Translocation Without Degradation of IκBα
Authors: Canty Timothy G. , Boyle Edward M. , Farr Angie , Morgan Elizabeth N. , Verrier Edward D. , Pohlman Timothy H.
Published: July 2021

Background—
Rel/NF-κB, an oxidative stress–responsive transcription factor, participates transiently in the control of gene expression. The cellular mechanisms that mediate NF-κB activation during ischemia (and during reperfusion in the course of treating ischemia) are not known.

Methods and Results—
To investigate the NF-κB activation induced during oxidative stress, we examined human cardiac tissue obtained during surgical procedures requiring cardiopulmonary bypass. In vitro, we examined human umbilical vein endothelial cells (HUVECs) exposed to hypoxia, reoxygenation after hypoxia, or a reactive oxygen intermediate (H
2
O
2
). Electrophoretic mobility shift assays performed on right atrial tissue revealed prominent NF-κB activation after hearts had been exposed to ischemia and reperfusion. The assays also showed that NF-κB activation was observed in hypoxic HUVECs after reoxygenation and in cultures treated with H
2
O
2
(500 μmol/L). Pervanadate (200 μmol/L) also induced marked NF-κB activation in HUVECs, indicating that H
2
O
2
-induced NF-κB activation is potentiated by the inhibition of tyrosine phosphatases. Western blotting of cytoplasmic IκBα demonstrated that NF-κB activation induced by oxidative stress was not associated with IκBα degradation. In contrast, tumor necrosis factor-α–induced NF-κB activation occurred in concert with degradation of IκBα. Inhibition of IκBα degradation with a proteasome inhibitor, MG-115, blocked NF-κB activation induced by tumor necrosis factor-α; however, MG-115 had no effect on NF-κB activation during oxidative stress.

Conclusions—
This study demonstrated a stimulus-specific mechanism of NF-κB activation in endothelial cells that acts independently of IκBα degradation and may require tyrosine phosphorylation.
Aortic Root Characteristics of Human Pulmonary Autografts
Authors: Carr-White Gerald S. , Afoke A. , Birks E. J. , Hughes S. , O’Halloran A. , Glennen Sally , Edwards Sue , Eastwood M. , Yacoub Magdi H.
Published: July 2021

Background
—After pulmonary autograft replacement of the aortic valve and root, the pulmonary artery (PA) wall is subjected to higher pressures. Concern exists that this may lead to structural and functional changes in the implanted autograft and subsequent aortic root dilatation and neoaortic regurgitation. We therefore assessed root dimensions and neoaortic regurgitation, morphological structure, and mechanical behavior in patients who underwent the Ross operation.

Methods and Results
—Seventy-four patients who were randomized to undergo aortic valve replacement with an aortic homograft or a pulmonary autograft were followed up echocardiographically for up to 4 years and had their aortic root dimensions measured at the level of the annulus, sinuses, and sinotubular junction. In a separate series of 18 patients who underwent pulmonary autograft surgery and 8 normal organ donors, samples from the PA and aorta were analyzed for medial wall thickness, distribution of the staining of collagen and elastin, and elastin fragmentation. Finally, stress-strain curves were obtained from samples of the PA and aorta from 9 patients who underwent pulmonary autograft surgery and from 1 patient in whom a 4-month-old autograft was explanted. No patient in either group had aortic dilatation at any level of >20% or more than mild aortic regurgitation at up to 4 years of follow-up. The aortic media was thicker in both autografts and normal donors (
P
<0.01), and there was a trend for the PA media to be thicker in the autograft group. Elastic fiber in all aortas showed little or no variation, whereas in the PA, there was considerable variation in fragmentation. Patients with higher preoperative PA pressures tended to have lower fragmentation scores (χ
2
P
<0.01). The lower stiffness modulus, higher stiffness modulus, and maximum tensile strength of the aorta was 34% to 38% higher than that of the PA (
P
<0.01); however, the 4-month-old autograft appeared to show adaptation in mechanical behavior.

Conclusions
—In our series of patients, there was no significant progressive dilatation of the aortic root. We demonstrated differences in the anatomic structure and mechanical behavior of the PA in vitro and highlighted histological and mechanical modes of adaptation.
A Prospective Analysis of the Immunogenicity of Cryopreserved Nonvalved Allografts Used in Pediatric Heart Surgery
Authors: Breinholt John P. , Hawkins John A. , Lambert Linda M. , Fuller Thomas C. , Profaizer Tracie , Shaddy Robert E.
Published: July 2021

Background
—The purpose of this study was to prospectively determine the immunogenicity of nonvalved allograft tissue used to repair congenital heart defects.

Methods and Results
—We prospectively analyzed the immune response of 11 children, 1.4 months to 10 years of age, who required nonvalved allografts to alleviate stenosis during repair of congenital heart defects. In 7 patients, pulmonary arterial grafts were used; in 3 patients, monocusp pulmonary artery grafts were used; and in 1 patient, a section of glutaraldehyde-preserved allograft pericardium was used. We measured the level of HLA panel-reactive antibody (PRA) before surgery, 1 week after, 1 month after, and 3 months after surgery. PRA was determined by the antiglobulin technique and flow cytometry. HLA class I and class II antibodies measured by either technique were negligible before and 1 week after surgery. Nine of 11 patients (82%) exhibited a significant immune response at 1 month after surgery that further increased at 3 months. The measured PRA for class I antibodies with the antiglobulin technique increased to 43±36% at 1 month and to 69±38% at 3 months after surgery. Flow cytometry class I PRA measurements were similar. Class II PRA increased to 26±34% at 1 month and to 41±36% at 3 months. Age negatively correlated with the degree of elevation of PRA, but neither allograft area nor the area indexed to patient body surface area correlated with PRA.

Conclusions
—Cryopreserved nonvalved allografts induce a strong HLA antibody response in the majority of children.
Deloading of the Left Ventricle by Ventricular Assist Device Normalizes Increased Expression of Endothelin ET
A
Receptors But Not Endothelin-Converting Enzyme-1 in Patients With End-Stage Heart Failure
Authors: Morawietz Henning , Szibor Marten , Goettsch Winfried , Bartling Babett , Barton Matthias , Shaw Sidney , Koerfer Reiner , Zerkowski Hans-Reinhard , Holtz Juergen
Published: July 2021

Background
—Ventricular assist devices (VAD) are implanted in patients with end-stage heart failure for bridging the time until heart transplantation, resulting in hemodynamic unloading of the failing heart, improved cardiac contractile and mitochondrial function, and reversal of cardiac hypertrophy. It is unknown whether VAD unloading may affect the cardiac endothelin (ET) system, which has been proposed as one of the putative pathomechanisms of heart failure.

Methods and Results
—With the use of standard-calibrated, competitive reverse-transcription–polymerase chain reaction mRNA expression of components of the ET system was analyzed in left ventricular myocardium from nonfailing donor hearts, from failing hearts without and with ACE inhibitor therapy, and from patients with end-stage heart failure at the time of VAD implantation and 103±15 days after VAD implantation during removal with subsequent heart transplantation. ET receptor A (ET
A
) was markedly upregulated in failing human myocardium. This increased ET
A
expression was not affected by ACE inhibitor treatment but was normalized by VAD unloading. ET
A
expression before or after VAD implantation did not correlate with duration of VAD implantation or suppression of Pro-ANP mRNA. ET
B
mRNA expression was unaffected by heart failure or VAD. In contrast, increased ET-converting enzyme-1 mRNA and ET-1 peptide levels in failing myocardium were partially normalized by ACE inhibition but not by VAD unloading.

Conclusions
—We conclude that VAD implantation normalizes ET
A
expression in failing human left ventricular myocardium, probably as the result of the beneficial effects of VAD unloading.
Disappearance of Aortic Intramural Hematoma and Its Significance to the Prognosis
Authors: Nishigami Kazuhiro , Tsuchiya Takeshi , Shono Hiroyuki , Horibata Yoko , Honda Takashi
Published: July 2021

Background
—An aortic intramural hematoma (IMH) is a form of aortic dissection (AD). IMHs regress with time or completely disappear in some patients, whereas they progress to overt AD in other patients. The purpose of the present study was to investigate how IMHs change serially during a follow-up period.

Methods and Results
—We analyzed 44 consecutive medically treated patients with IMHs, in whom transesophageal echocardiography (TEE) was performed serially at both 1 and 6 months after the onset. After TEE, the patients were followed with interviews (mean follow-up 1552±539 days). IMHs disappeared at 6 months in 21 patients (48%) (disappearance group), whereas IMHs were still demonstrated at 6 months in 20 patients (45%) (persistent group); in the disappearance group, IMHs disappeared at 1 month in 8 patients (18%). In 3 patients (7%) in whom an IMH was demonstrated at 1 month, overt AD occurred until 6 months. The disappearance group was younger than the persistent group (64±11 versus 72±8 years,
P
<0.01), and the maximum diameter of the aorta was smaller in the disappearance group than in the persistent group (33±5 versus 42±7 mm,
P
<0.01). During the long-term follow-up, overt AD occurred at 7 and 11 months in 2 patients, and progressive aortic dilatation that required surgical treatment occurred at 12 and 24 months in 2 of the persistent group patients, whereas neither overt AD nor progressive aortic dilatation occurred in the disappearance group. In the patients in whom overt AD occurred, the maximal aortic diameter was >45 mm and an IMH was demonstrated at 1 month. On the other hand, those with a maximal aortic diameter of <45 mm or a disappeared IMH did not have overt AD.

Conclusions
—IMHs disappeared until 1 month in 18% and until 6 months in 48% of patients with IMHs. The disappearance of IMHs was related to the maximum diameter of the aorta and age. Both a disappeared IMH and a maximal aortic diameter of <45 mm suggest a good prognosis.
Difference in Endothelium-Derived Hyperpolarizing Factor–Mediated Hyperpolarization and Nitric Oxide Release Between Human Internal Mammary Artery and Saphenous Vein
Authors: Liu Zhi-Gang , Ge Zhi-Dong , He Guo-Wei
Published: July 2021

Background
—The greater nitric oxide (NO) release that occurs in the internal mammary artery (IMA) when compared with the saphenous vein (SV) has been suggested by more endothelium-dependent relaxation in the IMA or measured by bioassay; however, no direct measurement of NO- or endothelium-derived hyperpolarizing factor (EDHF)–mediated hyperpolarization has been reported. The present study measured such hyperpolarization, as well as NO release, in these vessels.

Methods and Results
—IMA (n=46) and SV (n=61) segments taken from patients undergoing coronary surgery were studied in the organ chamber. Hyperpolarization (by intracellular glass microelectrode) and NO release (by NO-sensitive electrode) in response to acetylcholine and bradykinin, with and without incubation with N
G
-nitro-
l
-arginine, indomethacin, and oxyhemoglobin, were measured. The resting membrane potential of the smooth muscle cells from the IMA (58±0.8 mV; n=15) was higher than that in those from the SV (−62±0.9 mV; n=23;
P
=0.0001). The EDHF-mediated hyperpolarization induced by acetylcholine (10
−5
mol/L: −9.4±1.5 mV in IMA, n=10, versus −4.5±1.0 mV in SV, n=17;
P
<0.01) and bradykinin (10
−7
mol/L: −10.9±1.5 mV in IMA, n=8, versus −5.1±0.5 mV in SV, n=8;
P
<0.01) and the basal release of NO (16.8±1.6 nmol/L in IMA, n=13, versus 9.9±2.8 nmol/L in SV, n=13;
P
<0.001) were significantly greater in the IMA than in the SV. The duration of acetylcholine- and bradykinin-induced NO release was longer in the IMA than in the SV.

Conclusions
—The basal release of NO and EDHF-mediated hyperpolarization were significantly greater in the IMA than in the SV. In addition, the duration of the stimulated release of NO was longer in the IMA than in the SV. These differences may contribute to the superior long-term patency of IMA grafts.
Ten-Year Experience of Chordal Replacement With Expanded Polytetrafluoroethylene in Mitral Valve Repair
Authors: Kobayashi Junjiro , Sasako Yoshikado , Bando Ko , Minatoya Kenji , Niwaya Kazuo , Kitamura Soichiro
Published: July 2021

Background
—Mitral valve repair is the procedure of choice to correct mitral regurgitation (MR). Although chordal replacement with expanded polytetrafluoroethylene (ePTFE) has been widely accepted to repair anterior mitral prolapse and other difficult situations, the long-term results of the repair and the fate of ePTFE have not been delineated.

Methods and Results
—From July 1988 to April 1999, 74 patients (49 males, 25 females) aged 17 to 77 years (mean age 55.3±14.8 years) underwent mitral valve repair with chordal replacement with ePTFE. The follow-up period was from 6 months to 11.3 years (mean 4.6±3.2 years). The causes of MR were degenerative in 65 patients (88%) and infective in 9 (12%). Three patients had active infective endocarditis. Valve lesions were anterior in 35 patients, posterior in 10, and both anterior and posterior in 29. Various procedures for plasty of leaflets were necessary in 37 patients (50%). Atrial fibrillation was associated in 38 patients (51%), and the maze procedure has been performed in a selected group of 30 patients (41%) since July 1992. There was 1 in-hospital death (1.4%) and 3 late cardiac deaths (4.1%). More than moderate MR developed in 12 patients (17%) during the follow-up period. Three of these patients required early reoperation within 1 year due to hemolysis. Two patients underwent mitral valve replacement at 6 and 8 years after repair, respectively. The actuarial reoperation-free rates at 5 and 10 years were 94.3±2.8% and 81.7±9.1%, respectively. Sinus rhythm was restored in 21 patients (70%) with the maze procedure. There was only 1 thromboembolic episode (0.3%/patient-y) in a patient with atrial fibrillation who did not undergo the maze procedure. Event-free survival rates as assessed by the freedom from cardiac death, thromboembolism, reoperation, and anticoagulation-related hemorrhage at 5 and 10 years were 91.3±3.4% and 71.6±9.7%, respectively. There was no relationship between recurrent MR and the change of ePTFE. Structural analysis of the ePTFE resected during reoperation revealed no calcification and showed remaining flexibility and pliability. Protein infiltration was observed in the ePTFE, and collagenous proliferation was recognized at the site of fixation to the valve leaflet and the papillary muscle. The surface of the ePTFE was completely endothelialized, which may induce antithrombogenicity.

C
onclusions

—The long-term durability and biological adaptation of ePTFE as artificial chordae for mitral valve repair of MR were proved for >10 years.
Glutathione Reverses Endothelial Damage From Peroxynitrite, the Byproduct of Nitric Oxide Degradation, in Crystalloid Cardioplegia
Authors: Nakamura Masanori , Thourani Vinod H. , Ronson Russell S. , Velez Daniel A. , Ma Xin-Liang , Katzmark Sara , Robinson Jill , Schmarkey L. Susan , Zhao Zhi-Qing , Wang Ning-Ping , Guyton Robert A. , Vinten-Johansen Jakob
Published: July 2021

Background
—NO has been advocated as an adjunct to cardioplegia solutions. However, NO undergoes a rapid biradical reaction with superoxide anions to produce peroxynitrite (ONOO
−
). ONOO
−
in crystalloid cardioplegia solution induces injury to coronary endothelium and to systolic function after cardioplegia and reperfusion. However, ONOO
−
may be degraded to less lethal or cardioprotective intermediates with glutathione (GSH) in reactions separate from its well known antioxidant effects. We hypothesized that GSH detoxifies ONOO
−
and reverses defects in endothelial function and systolic function when present in crystalloid cardioplegia.

Methods and Results
—In anesthetized dogs on cardiopulmonary bypass, a 45-minute period of global normothermic ischemia was followed by 60 minutes of intermittent cold crystalloid cardioplegia (Plegisol) and 2 hours of reperfusion. The cardioplegia solution contained 5 μmol/L authentic ONOO
−
; catalase was included to attenuate the potential antioxidant effects of GSH and to unmask the effects on ONOO
−
. In 1 group (CP+GSH, n=5), the cardioplegia contained 500 μmol/L GSH, whereas 1 group received crystalloid cardioplegia without GSH (CCP, n=6). There were no group differences in postcardioplegia left ventricular systolic function (end-systolic pressure-volume relation, impedance catheter: CCP 10.0±2.4 versus CP+GSH 10.6±1.3 mm Hg/mL) or diastolic chamber stiffness (β-coefficient: CCP 0.35±0.2 versus CP+GSH 0.31±0.18). Myocardial neutrophil accumulation (myeloperoxidase activity) was attenuated in CP+GSH versus CCP (2.2±0.7 versus 5.4±1.2,
P
<0.05). In postexperimental coronary arteries, maximal endothelium-dependent relaxation was greater in CP+GSH than in CCP (118±6% versus 92±5%,
P
<0.05), with a smaller EC
50
value (−7.10±0.05 versus −6.98±0.03, respectively,
P
<0.05). Smooth muscle relaxation was complete in both groups. The adherence of neutrophils to postexperimental coronary arteries as a measure of endothelial function was less in CP+GSH than in CCP (98±18 versus 234±36 neutrophils/mm
2
,
P
<0.05). Nitrosoglutathione, a byproduct of the reaction between ONOO
−
and GSH, was greater in CP+GSH than in CCP (4.1±2.3 versus 0.4±0.2 μg/mL,
P
<0.05).

Conclusions
—GSH in crystalloid cardioplegia detoxifies ONOO
−
and forms cardioprotective nitrosoglutathione, resulting in attenuated neutrophil adherence and selective endothelial protection through the inhibition of neutrophil-mediated damage.
Bicuspid Aortic Valves Are Associated With Aortic Dilatation Out of Proportion to Coexistent Valvular Lesions
Authors: Keane Martin G. , Wiegers Susan E. , Plappert Ted , Pochettino Alberto , Bavaria Joseph E. , Sutton Martin G. St. John
Published: July 2021

Background
—Bicuspid aortic valves (BAVs) are associated with premature valve stenosis, regurgitation, and ascending aortic aneurysms. We compared aortic size in BAV patients with aortic size in control patients with matched valvular lesions (aortic regurgitation, aortic stenosis, or mixed lesions) to determine whether intrinsic aortic abnormalities in BAVs account for aortic dilatation beyond that caused by valvular hemodynamic derangement alone.

Methods and Results
—Diameters of the left ventricular outflow tract, sinus of Valsalva, sinotubular junction, and proximal aorta were measured from transthoracic echocardiograms in 118 consecutive BAV patients. Annular area was measured by planimetry, and BAV eccentricity was expressed as the ratio of the right leaflet area to the total annular area. Seventy-seven control patients with tricuspid aortic valves were matched for sex and for combined severity of regurgitation and stenosis. BAV patients (79 men and 39 women, aged 44.1±15.5 years) had varying degrees of regurgitation (84 patients [71%]) and stenosis (48 patients [41%]). Within the bicuspid group, multivariate analysis demonstrated that aortic diameters increased with worsening aortic regurgitation (
P
<0.001) and advancing age (
P
<0.05) but not with the severity of aortic stenosis. BAV patients had larger aortic diameters than did control patients at all ascending aortic levels measured (
P
<0.01), despite advanced age in the control patients.

Conclusions
—Aortic dimensions are larger in BAV patients than in control patients with comparable degrees of tricuspid aortic valve disease. Although more severe degrees of aortic regurgitation are associated with aortic dilatation in BAV patients, intrinsic pathology appears to be responsible for aortic enlargement beyond that predicted by hemodynamic factors.
Functional Living Trileaflet Heart Valves Grown In Vitro
Authors: Hoerstrup Simon P. , Sodian Ralf , Daebritz Sabine , Wang Jun , Bacha Emile A. , Martin David P. , Moran Adrian M. , Guleserian Kristine J. , Sperling Jason S. , Kaushal Sunjay , Vacanti Joseph P. , Schoen Frederick J. , Mayer John E.
Published: July 2021

Background
—Previous tissue engineering approaches to create heart valves have been limited by the structural immaturity and mechanical properties of the valve constructs. This study used an in vitro pulse duplicator system to provide a biomimetic environment during tissue formation to yield more mature implantable heart valves derived from autologous tissue.

Methods and Results
—Trileaflet heart valves were fabricated from novel bioabsorbable polymers and sequentially seeded with autologous ovine myofibroblasts and endothelial cells. The constructs were grown for 14 days in a pulse duplicator in vitro system under gradually increasing flow and pressure conditions. By use of cardiopulmonary bypass, the native pulmonary leaflets were resected, and the valve constructs were implanted into 6 lambs (weight 19±2.8 kg). All animals had uneventful postoperative courses, and the valves were explanted at 1 day and at 4, 6, 8, 16, and 20 weeks. Echocardiography demonstrated mobile functioning leaflets without stenosis, thrombus, or aneurysm up to 20 weeks. Histology (16 and 20 weeks) showed uniform layered cuspal tissue with endothelium. Environmental scanning electron microscopy revealed a confluent smooth valvular surface. Mechanical properties were comparable to those of native tissue at 20 weeks. Complete degradation of the polymers occurred by 8 weeks. Extracellular matrix content (collagen, glycosaminoglycans, and elastin) and DNA content increased to levels of native tissue and higher at 20 weeks.

Conclusions
—This study demonstrates in vitro generation of implantable complete living heart valves based on a biomimetic flow culture system. These autologous tissue-engineered valves functioned up to 5 months and resembled normal heart valves in microstructure, mechanical properties, and extracellular matrix formation.
Coordinate-Free Analysis of Mitral Valve Dynamics in Normal and Ischemic Hearts
Authors: Dagum Paul , Timek Tomasz A. , Green G. Randall , Lai David , Daughters George T. , Liang David H. , Hayase Motoya , Ingels Neil B. , Miller D. Craig
Published: July 2021

Background
—The purpose of this investigation was to study mitral valve 3D geometry and dynamics by using a coordinate-free system in normal and ischemic hearts to gain mechanistic insight into normal valve function, valve dysfunction during ischemic mitral regurgitation (IMR), and the treatment effects of ring annuloplasty.

Methods and Results
—Radiopaque markers were implanted in sheep: 9 in the ventricle, 1 on each papillary tip, 8 around the mitral annulus, and 1 on each leaflet edge midpoint. One group served as a control (n=7); all others underwent flexible Tailor partial (n=5) or Duran complete (n=6) ring annuloplasty. After an 8±2-day recovery, 3D marker coordinates were measured with biplane videofluoroscopy before and during posterolateral left ventricular ischemia, and MR was assessed by color Doppler echocardiography. Papillary to annular distances remained constant throughout the cardiac cycle in normal hearts, during ischemia, and after ring annuloplasty with either type of ring. Papillary to leaflet edge distances similarly remained constant throughout ejection. During ischemia, however, the absolute distances from the papillary tips to the annulus changed in a manner consistent with leaflet tethering, and IMR was observed. In contrast, during ischemia in either ring group, those distances did not change from preischemia, and no IMR was observed.

Conclusions
—This analysis uncovered a simple pattern of relatively constant intracardiac distances that describes the 3D geometry and dynamics of the papillary tips and leaflet edges from the dynamic mitral annulus. Ischemia perturbed the papillary-annular distances, and IMR occurred. Either type of ring annuloplasty prevented such changes, preserved papillary-annular distances, and prevented IMR.
Does Cardioplegia Type Affect Outcome and Survival in Patients With Advanced Left Ventricular Dysfunction?
Authors: Flack Joseph E. , Cook James R. , May Susanne J. , Lemeshow Stanley , Engelman Richard M. , Rousou John A. , Deaton David W.
Published: July 2021

Background
—There is controversy regarding which cardioplegic solution, temperature, and route of administration provides superior protection. The CABG Patch Trial enrolled a high-risk group of coronary artery disease patients with an ejection fraction of <36%. Thus, they constitute an ideal group to benefit most from optimal cardioplegic protection.

Methods and Results
—All patients randomized into the trial were compared with respect to the use of blood and crystalloid cardioplegia. In addition, a questionnaire was sent to surgeons requesting blood cardioplegic temperature and route. Patients receiving crystalloid cardioplegia versus those receiving blood cardioplegia were found to have significantly more operative deaths (2% versus 0.3%,
P
=0.02), postoperative myocardial infarctions (10% versus 2%,
P
<0.001), shock (13% versus 7%,
P
=0.013), and postoperative conduction defects (21.6% versus 12.4%,
P
=0.001). Despite this, early death (6% crystalloid versus 4% blood cardioplegia) and late death (24% crystalloid versus 21% blood cardioplegia) statistics were not significantly different. Patients receiving normothermic blood had less postoperative right ventricular dysfunction (10%) than did patients receiving cold blood (25%) or cold blood with warm reperfusion (30%) (
P
=0.004). There was no significant difference in early or late death. Finally, patients who received combined antegrade and retrograde cardioplegia had significantly less inotrope use (71% versus 84%,
P
=0.002), right ventricular dysfunction (23% versus 41%,
P
=0.001), and postoperative balloon pump use (12% versus 19%,
P
=0.02) than did those who received antegrade cardioplegia. There was no difference in survival.

Conclusions
—Blood cardioplegia and combined antegrade and retrograde cardioplegia are superior to crystalloid and antegrade cardioplegia alone for postoperative morbidity. Despite this, there is no significant difference in early or late survival.
Humoral Immune Response During Coronary Artery Bypass Grafting
Authors: Diegeler Anno , Doll Nicolas , Rauch Thomas , Haberer Dorothea , Walther Thomas , Falk Volkmar , Gummert Jan , Autschbach Rüdiger , Mohr Friedrich-Wilhelm
Published: July 2021

Background
—The introduction of limited approaches to the heart and the avoidance of cardiopulmonary bypass (CPB) aim to reduce the invasiveness of CABG by decreasing the systemic release of inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8, as well as the anti-inflammatory agent IL-10. This study compares the humoral immune response in patients undergoing CABG with standard, minimally invasive, and “off-pump” techniques.

Methods and Results
—Thirty patients were divided into 3 operative groups: full sternotomy approach plus CPB (group A); full sternotomy approach, off pump (group B); and limited left anterior thoracotomy, off pump (group C). Plasma levels of TNF-α receptors p55 and p75, IL 6, IL-8, and IL-10 were taken at baseline, during CPB, and at 4, 24, and 48 hours and 6 days after surgery. A significant increased release of activated complement factors C5a and C3d, IL-8, and IL-10 was observed in patients subjected to CPB (group A) during the initial period and for a short time after perfusion (
P
<0.05). TNF-α receptors p55 and p75 showed a prolonged elevation (up to 48 hours) in the CPB group compared with the 2 off-pump groups. IL-6 showed no different release among the 3 surgical groups throughout the entire period. There was no significant difference in any parameter measured in relation to the type of operative approach.

Conclusions
—There is an inflammatory, as well as an anti-inflammatory, response during CABG that is related to the general surgical trauma. The release of immune mediators is enhanced by the use of CPB during various perioperative and postoperative phases. The type of operative approach did not influence this immune response.
Gestational age and arterial characteristics at 29 years of age in the Atherosclerosis Risk in Young Adults (ARYA) study.
Authors: Oren Anath , Vos Lydia E , Uiterwaal Cuno SPM , Bak Annette AA , Gorissen Wim HM , Grobbee Diederick E , Bots Michiel L
Published: July 2021

P28

Background: Several studies have indicated that prenatal condition may affect cardiovascular risk factors and thereby risk of cardiovascular morbidity and mortality. Based on these findings it has been suggested that impaired intra-uterine growth leads to increased risk of atherosclerosis. Data directly relating prenatal factors to vascular changes are limited and restricted to older individuals. In the ARYA study we evaluated whether birth characteristics are associated with subclinical atherosclerosis in young adults. Methods: The ARYA-study is a cohort study of 750 men and women aged 27-30 years. Information on birth characteristics (gestational age, birth weight, birth length) was obtained from the municipal health service medical files. At baseline, information on cardiovascular risk factors was obtained by questionnaire and measurements during two visits at the research centre. Arterial characteristics were non-invasively assessed by measuring common carotid intima-media thickness (CIMT) at both carotid arteries and by measuring aortic stiffness by pulse wave velocity (PWV). At present, data on 204 subjects are available for analysis. Linear regression analysis was applied and results are adjusted for age, gender, smoking and family history. Results: This sub-analysis comprised of 204 young adults (47% men) with a mean age of 29.2 (0.5). Mean gestational age was 39.8 (1.8) weeks, birth weight 3420 (539) gram, birth length 51.0 (2.5) cm, CIMT 0.51 (0.05) mm and mean PWV 6.2 (1.0) m/s. With increasing gestational age (in weeks), CIMT decreased with 0.006 mm [CI: -0.010, -0.002], whereas PWV decreased with 0.112 m/s [CI: -0.217, -0.008]. These associations were independent of birth weight. Conclusion: This preliminary analysis of the ARYA-study indicates that decreased gestational age relates to subclinical atherosclerosis already in young adulthood.
Gender Disparities in Procedure Use for Acute Myocardial Infarction in the United States, 1995-1997
Authors: Bertoni Alain G , Brancati Frederick L
Published: July 2021

P03

Gender disparities in procedure use for acute myocardial infarction (AMI) have been well documented in selected populations in the 1980s and early 90s. However, little is known about recent trends in disparities in the general population. Therefore we conducted a series of cross-sectional analyses of data from the Nationwide Inpatient Sample for years 1995 through 1997 to compare rates of catheterization, angioplasty and coronary artery bypass grafting (CABG) performed prior to discharge for acute myocardial infarction in men vs. women. The NIS includes data (including demographics, diagnoses and procedures) on all discharges from over 900 representative civilian hospitals in 22 states. We identified 425,236 discharges with AMI (ICD9 code 410) as the first listed diagnosis during 1995-97. The cohort was 39% female (mean age 71.7) and 61% male (mean age 64.4). From 1995 to 97, catheterization rates increased in women (38.8% to 41.8%)and men (49.7% to 52.4%) as did rates of angioplasty (women 17.1% to 19.9%, men 23.0% to 26.6%) and CABG (women 8.3% to 8.7%, men 11.9% to 12.4%) After adjusting for age, race, and comorbidities, women were less than men to undergo catheterization in 1995 (odds ratio [OR] 0.85, 95% confidence interval [CI] 0.83-0.87), 1996 (OR 0.85, 95%CI 0.83-0.87), and 1997 (OR 0.87 95%CI 0.85-0.87). This gender disparity was even greater among adults aged 65 and older (adjusted OR 0.70, 95%CI 0.68-0.72 in 1995 and 96; and 0.71, 95%CI 0.69-0.72 in 1997). Women were also less likely to undergo CABG (adjusted OR 0.72, 95%CI 0.70-0.74 in 1995, 96 and 97). Among patients who underwent catheterization, women remained less likely to go on to CABG than men (adjusted OR 0.77, 95%CI 0.75-0.79). In contrast,women were only slightly less likely to undergo angioplasty (adjusted OR 0.93, 95%CI 0.91-0.94) and, once catheterized, were actually more likely to go on to angioplasty (adjusted OR 1.03, 95%CI 1.01-1.05). While procedure use for AMI is rising for men and women, these recent nationwide data suggest that women remain much less likely to undergo catheterization or CABG, but about equally likely to undergo angioplasty.