bluuebunny/crossref_metadata_2025 huggingface dataset:
The incidence of treated hypertension and time trends in the use of antihypertensive medications in older adults
Authors: Psaty Bruce M. , Smith Nicholas L. , Manolio Teri A. , Heckbert Susan R. , Gottdiener John S. , Burke Gregory L. , Powe Neil R. , Weissfeld Joel L. , Enright Paul , Furberg Curt D.
Published: July 2021

0011

In the Cardiovascular Health Study (CHS), a cohort study of adults aged 65 or older, annual examinations included blood pressure measurements and an assessment of medication use. In 1989-90, 5201 subjects were recruited, and in 1992-3, another 687 African Americans joined the cohort. At baseline, 40% of the cohort had treated hypertension. During follow-up, 1091 started antihypertensive treatment, and 639 stopped. By 1997, 55% of the cohort had treated hypertension. Between baseline and the 1996-7 exam, the annual incidence of treated hypertension increased from 5.5% up to 8.3% as the cohort aged. In multivariate analysis, high levels of weight, systolic and diastolic blood pressure, non-white race, female sex, target organ disease, non-smoking, and a family history of CHD were all associated with incident treated hypertension. The adjusted incidence was higher in African Americans than in whites (OR = 1.32; 95% CI = 1.04-1.67). Among treated hypertensive participants, about 5% stopped antihypertensive treatment each year; and stopping was associated with older age, the use of fewer medications, and lower levels of systolic blood pressure. Between 1989 and 1997, among subjects free of coronary disease, the use of thiazide diuretics decreased from 60% to 40%, and β-blockers from 26% to 21%. During the same period, the use of ACE inhibitors increased steadily from 17% to 31%; α-blockers from 6% to 9%; and calcium channel blockers increased from 14% to 35% in 1995 and thereafter remained stable. A similar pattern of trends was apparent in subjects with coronary disease: for instance, thiazide diuretic use declined from 36% to 20% in subjects with coronary disease. Even though clinical trials published in the early 1990s have documented the importance of low-dose diuretic therapy for preventing the cardiovascular complications of untreated high blood pressure in older adults, the use of proven, effective, and inexpensive antihypertensive therapies declined between 1989 and 1997.
Incidence, Location, Pathology, and Significance of Pulmonary Homograft Stenosis After the Ross Operation
Authors: Carr-White Gerald S. , Kilner Philip J. , Hon Jimmy K.F. , Rutledge Thomas , Edwards Sue , Burman Elisabeth D. , Pennell Dudley J. , Yacoub Magdi H.
Published: July 2021

Background

The Ross operation has several theoretical advantages. However, concern exists regarding evolving pathology in the pulmonary homograft.

Methods and Results

Consecutive patients (n=144; mean age 31 years, range 2 months to 64 years) undergoing the Ross operation were studied between 1993 and 2000. Echocardiographic examination of the pulmonary homograft was performed immediately after surgery, then at yearly intervals for a mean interval of 48 months. Fifteen patients (mean age 37 years) in whom echocardiography revealed peak pulmonary gradients ≥30 mm Hg (mean 46±18 mm Hg) underwent MRI with velocity mapping in a Picker 1.5-T magnet. No patient had more than mild pulmonary regurgitation. Four patients required reoperation for rapidly progressive pulmonary homograft stenosis; in all 4, there was macroscopic and microscopic evidence of a pronounced chronic adventitial reaction, with perivascular infiltration producing extrinsic compression. Freedom from any pulmonary homograft stenosis at 7-year follow-up was 79.7%, with instantaneous hazard falling to zero after 4 years. Freedom from reoperation at 7 years was 96.7%. In those studied with MRI, there was evidence of narrowing of the whole homograft or distal suture line in 14 of 15 patients, with obvious excess surrounding tissue in 11. Mean minimum diameter and peak velocity by MRI were 11±2 mm and 3.2±0.7 m/s, respectively. Multivariate analysis of patient-, surgery-, and homograft-related variables did not reveal any significant risk factors for development of neopulmonary stenosis.

Conclusions

Pulmonary homograft stenosis after the Ross operation is clinically important and appears to represent an early postoperative inflammatory reaction to the pulmonary homograft that leads to extrinsic compression and/or shrinkage.
Procalcitonin, A Donor-Specific Predictor of Early Graft Failure-Related Mortality After Heart Transplantation
Authors: Wagner Frank D. , Jonitz Britta , Potapov Evgenij V. , Qedra Naser , Wegscheider Karl , Abraham Klaus , Ivanitskaia Ekaterina A. , Loebe Matthias , Hetzer Roland
Published: July 2021

Background

To date, donor-specific markers to predict outcome after heart transplantation (HTx) are unknown. Increased procalcitonin (PCT) levels have been found in infectious inflammation with systemic reactions and/or poor organ perfusion but have not been studied in heart donors. We evaluated PCT as a predictor of early graft failure-related mortality after HTx.

Methods and Results

PCT and C-reactive protein (CRP) serum concentrations were measured in samples collected immediately before pericardium opening from 81 consecutive brain-dead multiple-organ donors. Donors for high-urgency-status recipients (n=2) were excluded from analysis. The remaining donors were retrospectively divided into 2 groups: donors for recipients who died within 30 days after HTx, after an early graft failure (group II, n=8), and all other donors (group I, n=71). No differences in donor and recipient demographic characteristics were found between groups. Areas under the receiver operating characteristic curves for graft failure-related mortality were 0.71 for PCT and 0.64 for CRP. A PCT value >2 ng/mL as a predictor of graft failure-related mortality had a specificity of 95.8% and sensitivity of 50.0%. The odds ratio for graft failure-related mortality for recipients of hearts from donors with PCT levels >2 ng/mL was 22.7 (unadjusted, 95% CI 3.7 to 137.8,
P
=0.0007) and 43.8 (after adjustment for prespecified potential confounders, 95% CI 1.4 to 1361.0,
P
=0.031).

Conclusions

A PCT level >2 ng/mL in a cardiac donor at the time of explantation appears to predict early graft failure-related mortality.
All-Blood (Miniplegia) Versus Dilute Cardioplegia in Experimental Surgical Revascularization of Evolving Infarction
Authors: Velez Daniel A. , Morris Cullen D. , Budde Jason M. , Muraki Satoshi , Otto Rachel N. , Guyton Robert A. , Vinten-Johansen Jakob
Published: July 2021

Background

The advantages of blood cardioplegia include the oxygen-carrying capacity, superior oncotic and buffering properties, and endogenous antioxidants contained in blood. However, the partial dilution of blood in 4:1 (blood:crystalloid) cardioplegic solutions may nullify these advantages and progressively dilute blood during continuous retrograde delivery. This study tested the hypothesis that all-blood (66:1) cardioplegia provides superior myocardial protection compared with dilute (4:1) cardioplegia delivered in a continuous retrograde modality during surgical reperfusion of evolving myocardial infarction.

Methods and Results

After 60 minutes of left anterior descending coronary artery (LAD) occlusion, anesthetized canines were placed on cardiopulmonary bypass and randomized to either all-blood cardioplegia (AB group) or dilute blood cardioplegia (Dil group). After cross clamping, arrest was induced with 5 minutes of tepid (30°C) antegrade potassium all-blood or dilute blood cardioplegia and maintained with tepid retrograde coronary sinus cardioplegia for a total of 1 hour. The LAD was released after 30 minutes of arrest, simulating revascularization. The cardioplegia hematocrit for the Dil group was lower than that for the AB group (7±1% versus 12±2%,
P
<0.05); at the end of bypass, systemic hematocrit was lower in the Dil group than in the Ab group (15±1% versus 20±1%,
P
<0.05). Infarct size (triphenyltetrazolium chloride staining) was comparable between the AB and Dil groups (29.6±2.9% versus 30.3±3.9% of area at risk), and there was no difference in area-at-risk myocardium systolic shortening (by sonomicrometry, −0.3±1% versus −0.4±1%). Tissue edema after bypass tended to be greater in the Dil group compared with the AB group in the heart (82±0% versus 81±1%), lung (79±1% versus 78±1%), liver (75±1% versus 74±0%), and skeletal muscle (76±1% versus 73±2%) and was significantly greater in the duodenum (80±1% versus 79±1%,
P
<0.05) and kidney (82±1% versus 79±1%,
P
<0.05). Postexperimental endothelial function (relaxation of acetylcholine) was impaired in LADs of the AB group versus the Dil group (59±6% versus 77±5%,
P
<0.05).

Conclusions

Both all-blood cardioplegia and dilute cardioplegia have disadvantages, but these do not have an impact on the pathogenesis of infarct size or recovery of regional contractile function.
Biochemical and Structural Evidence for Pig Myocardium Adherens Junction Disruption by Cardiopulmonary Bypass
Authors: Bianchi Cesario , Araujo Eugenio G. , Sato Kaori , Sellke Frank W.
Published: July 2021

Background

Given that cardiopulmonary bypass (CPB) is associated with edema and heart dysfunction and that adherens junctions may regulate vascular permeability barrier integrity and cardiomyocyte function, we investigated adherens junction protein steady-state levels in a pig model of CPB.

Methods and Results

Pigs were subjected to normothermic CPB for 90 minutes, followed by post-CPB perfusion for 90 minutes. Atrial and ventricular myocardium tissue samples were harvested before institution of bypass (basal levels) and at the end of post-CPB perfusion. Adherens junctions were analyzed by either total lysate or cadherin immunoprecipitates that were immunoblotted for pan-cadherin, VE-cadherin, β-catenin, and γ-catenin. Adherens junction solubility was addressed with Triton X-100 extraction. Frozen tissue sections were labeled with the same antibodies, and adherens junctions were visualized by confocal microscopy. Immunoblotting of total lysates revealed an increase in smaller-molecular-weight fragments of VE-cadherin, β-catenin, and γ -catenin after post-CPB perfusion, indicating partial protein degradation. Smaller-molecular-weight fragments recognized by VE-cadherin and β-catenin antibodies were also obtained from VE-cadherin immunoprecipitation, indicating degradation of endothelial cell adherens junctions. A prominent increase in adherens junction complex solubility was observed in post-CPB perfusion samples. Confocal microscopy of hearts obtained before CPB showed a continuous, homogeneous pattern of cell-cell labeling that contrasted with an irregular, discontinuous, punctuate, or zigzag pattern observed in post-CPB perfusion samples, corroborating biochemical data.

Conclusions

These results indicate that CPB is associated with signs of degradation of endothelial and cardiomyocytes adherens junctions, pointing to a molecular mechanism leading to increased vascular permeability and cardiomyocyte dysfunction.
Gelatin Sheet Incorporating Basic Fibroblast Growth Factor Enhances Healing of Devascularized Sternum in Diabetic Rats
Authors: Iwakura Atsushi , Tabata Yasuhiko , Tamura Nobushige , Doi Kazuhiko , Nishimura Kazunobu , Nakamura Tatsuo , Shimizu Yasuhiko , Fujita Masatoshi , Komeda Masashi
Published: July 2021

Background

Poor healing of the sternum often limits the use of bilateral internal thoracic arteries (BITAs) after coronary bypass surgery in diabetic patients. We have reported that a gelatin sheet that incorporates basic fibroblast growth factor (bFGF) accelerates sternal healing after BITA removal in normal rats. This study evaluated the effects of the above method for sternal healing in diabetic animals.

Methods and Results

Diabetic Wistar rats with blood glucose levels >400 mg/dL and body-weight loss >20 g were established by a single intravenous injection of streptozotocin (55 mg/kg). After median sternotomy and BITA removal, 16 diabetic rats received either a gelatin sheet that incorporated bFGF (100 μg/sheet) on the posterior table of the sternum (FGF group, n=9) or no gelatin sheet (control, n=7). Peristernal blood flow, as measured by a noncontact laser Doppler 4 weeks after surgery in the FGF group, recovered to the preoperative level (106±10% versus 82±9%,
P
<0.01), and marked angiogenesis was also observed around the sternum in the FGF group (30.5±3.2 versus 15.8±2.7 vessels/unit area,
P
<0.01). Deep sternal wound complications developed in 5 control rats but only in 1 rat in the FGF group (
P
<0.05). In the FGF group, histological examination showed improved sternal healing (excellent in 6 rats and slow/poor healing in 3). Bone mineral content as assessed by dual-energy x-ray absorptometry was greater in the FGF group (75.9±18.1 versus 48.9±10.7 mg,
P
<0.05). Bone mineral density of the sternum was similar between the 2 groups.

Conclusions

A gelatin sheet that incorporates bFGF may offset sternal ischemia and accelerate sternal bone regeneration and healing, even in diabetic patients.
Comparison of Nitric Oxide Release and Endothelium-Derived Hyperpolarizing Factor–Mediated Hyperpolarization Between Human Radial and Internal Mammary Arteries
Authors: He Guo-Wei , Liu Zhi-Gang
Published: July 2021

Background

Arterial grafts for CABG have been used increasingly, and the radial artery (RA) has become a preferable graft, secondary to the internal mammary artery (IMA). In the present study, we investigated and compared NO release and endothelium-derived hyperpolarizing factor (EDHF)-mediated hyperpolarization for IMA and RA.

Methods and Results

IMA and RA segments taken from CABG patients were placed in an organ chamber. An NO-sensitive electrode (to directly measure NO release) or intracellular glass microelectrode (to measure membrane potential) was used to study NO or EDHF in response to acetylcholine (ACh) and bradykinin (BK) before and after incubation with indomethacin (a cyclooxygenase inhibitor),
N
G
-nitro-
l
-arginine (an NO synthase inhibitor), and oxyhemoglobin (an NO scavenger). The resting membrane potential of the smooth muscle cells of IMA and RA was −58±0.84 (n=61) and −61±1.3 (n=46) mV, respectively (
P
=0.03). BK-induced EDHF-mediated hyperpolarization in the IMA was significantly greater than that in RA (BK 10
−
7
mol/L: −10.9±1.5 [n=7] versus −5.8±0.9 [n=6] mV,
P
=0.04). The basal (16.8±1.9 versus 11.1±1.0 nmol/L, n=12,
P
=0.02) and stimulated releases of NO in IMA were significantly greater for BK (44.3±4.0 versus 25.8±3.6 nmol/L, n=8,
P
=0.004) and lasting longer for ACh (9.5±2.0 versus 6.6±3.6 minutes, n=12,
P
=0.03) than those in RA.

Conclusions

The basal and stimulated releases of NO and EDHF-mediated hyperpolarization in the IMA are significantly greater than that in the RA. The lower capacity of NO release may contribute to the susceptibility of RA to the perioperative vasospasm and may have an impact on the long-term graft patency.
Surgical Management of Left-Sided Carcinoid Heart Disease
Authors: Connolly Heidi M. , Schaff Hartzell V. , Mullany Charles J. , Rubin Joseph , Abel Martin D. , Pellikka Patricia A.
Published: July 2021

Background

Carcinoid involvement of left-sided heart valves has been reported in patients with a patent foramen ovale, carcinoid tumor of the lung, and active carcinoid syndrome with high levels of serotonin. The present study details the clinical features and surgical management of patients with carcinoid heart disease affecting both left- and right-sided valves.

Methods and Results

Eleven patients (7 men, 4 women) with symptomatic carcinoid heart disease underwent surgery for left- and right-sided valve disease between 1989 and 1999. Mean age was 57±9 years, and median preoperative NYHA class was 3. All patients had metastatic carcinoid tumors and were on somatostatin analog. Of 11 patients, 5 (45%) had a patent foramen ovale; 1 of these also had a primary lung carcinoid tumor. Surgery included tricuspid valve replacement in all patients, pulmonary valve replacement in 3 and valvectomy in 7, mitral valve replacement in 6 and repair in 1, aortic valve replacement in 4 and repair in 2, CABG in 2, and patent foramen ovale closure in 5. One myocardial metastatic carcinoid tumor was removed. There were 2 perioperative deaths. At a mean follow-up of 41 months, 4 additional patients were dead. All but 1 surgical survivor initially improved ≥1 functional class. No patient required reoperation.

Conclusions

Carcinoid heart disease may affect left- and right-sided valves and occurred without intracardiac shunting in 55% of this surgical series. Despite metastatic disease that limits longevity, operative survivors had improvement in functional capacity. Cardiac surgery should be considered for select patients with carcinoid heart disease affecting left- and right-sided valves.
Anterior Chordal Transection Impairs Not Only Regional Left Ventricular Function But Also Regional Right Ventricular Function in Mitral Regurgitation
Authors: Le Tourneau Thierry , Grandmougin Daniel , Foucher Claude , McFadden Eugene P. , de Groote Pascal , Prat Alain , Warembourg Henri , Deklunder Ghislaine
Published: July 2021

Background

Preservation of annuloventricular continuity through the chordae tendinae aims to maintain left ventricular (LV) function and thus improve postoperative prognosis. This study was designed to prospectively investigate the effect of anterior chordal transection on global and regional LV and right ventricular (RV) function in mitral regurgitation (MR).

Methods and Results

Sixty-five patients with severe MR underwent radionuclide angiography before and after either mitral valve (MV) repair (42 patients) or replacement with anterior chordal transection (23 patients). LV and RV ejection fractions (EF) were determined at rest. Both ventricles were divided into 9 regions to analyze regional EF and the effect of anteromedial translation related to surgery. After surgery there was a significant decrease in LVEF (
P
=0.038) and an increase in RVEF (
P
=0.036). However, LVEF did not change after MV repair (63.8±9.9% to 62.6±10.3%), whereas RVEF improved (40.7±10.1% to 44.5±8.1%,
P
=0.027). In contrast, LVEF decreased after MV replacement (61.7±10.1% to 57.2±9.9%,
P
=0.03), and RVEF was unchanged (40.9±10.9% to 41.3±9.1%). LVEF 4 and 5, in the area of anterior papillary muscle insertion, were impaired after MV replacement compared with MV repair (region 4, 77.6±16.7% versus 87.7±10.8%,
P
=0.005, and region 5, 73.9±19.3% versus 89.9±13.1%,
P
<0.001). Moreover, anterior chordal transection led to a significant impairment in the apicoseptal region of the RV (RVEF 4, 50.3±15.6% versus 59.3±13.8%,
P
=0.02).

Conclusions

Anterior chordal transection during MV replacement for MR impairs not only regional LV function but also regional RV function.
Coronary Artery Bypass With Only In Situ Bilateral Internal Thoracic Arteries and Right Gastroepiploic Artery
Authors: Nishida Hiroshi , Tomizawa Yasuko , Endo Masahiro , Koyanagi Hitoshi , Kasanuki Hiroshi
Published: July 2021

Background

With the rapid advance of catheter intervention, the direction taken by surgeons is not only to make conventional CABG less invasive but also to pursue better long-term results by using more arterial conduits.

Methods and Results

Between July 1989 and April 2000, 239 patients (218 men, 21 women) with a mean age of 59.7 (range 39 to 79) years underwent CABG with exclusive use of both internal thoracic arteries (ITAs) and the right gastroepiploic artery (RGEA). ITA grafts were harvested by using the skeletonization technique. Most patients (96%) had either triple-vessel or left main disease. Fifty percent of the patients were diabetic, and 16 were being treated with insulin. The left ventricular ejection fraction was ≤40% in 46 patients (19%). Eleven patients (5%) had chronic renal failure and were on hemodialysis. Follow-up was completed in 235 patients (98%). Postoperative follow-up averaged 43 (range 1 to 129) months. Sequential grafting was performed in 64 patients, and the mean number of anastomoses was 3.3. One patient (0.4%) died of mediastinitis on the 53rd postoperative day. Graft patency was confirmed angiographically in 230 patients (96%) 2 to 3 weeks after surgery. The patency rate was 97.1% for the left ITA, 99.6% for the right ITA, and 95.5% for the RGEA. Five-year actuarial survival rate was 92.9%, and the cardiac death-free rate was 97.8%.

Conclusions

Complete arterial grafting with both ITAs and RGEA was associated with minimal operative risk, a high early graft patency rate, and excellent long-term results.
Left Mini-Thoracotomy for Beating Heart Bypass Grafting
Authors: Dewey Todd M. , Magee Mitchell , Edgerton James , Vela Rhonda , Prince Syma L. , Acuff Tea , Mack Michael J.
Published: July 2021

Background

Progression of disease and bypass graft attrition results in a population of patients who require repeated coronary interventions. Frequently, these patients have patent internal mammary artery grafts and require isolated intervention to the circumflex distribution. As an alternative to high-risk repeated sternotomy and conventional bypass surgery or catheter-based intervention, the circumflex marginal vessels may be approached by thoracotomy. We reviewed our experience in revascularizing the circumflex distribution with off-pump techniques via left mini-thoracotomy.

Methods and Results

Thirty-two patients underwent off-pump bypass grafting of the circumflex vessels via thoracotomy from December 1995 to April 2000. Twenty-seven patients presented with circumflex disease after having previous bypass grafting. Five patients, who presented with circumflex disease and either nondiseased or ungraftable disease in their other arteries, were revascularized as a primary procedure. There was no observed mortality. Seven patients (22%) required inotropes on leaving the operating room, and 3 patients (9.4%) received transfusion of packed red blood cells. There was 1 reoperation for bleeding and 1 patient with a postoperative neurological deficit. There were no perioperative myocardial infarctions. The average length of stay was 4.8 days from time of surgery to discharge.

Conclusions

Off-pump grafting via thoracotomy provides a safe and effective alternative approach for patients requiring limited revascularization. Potential cardiac injury and danger to viable grafts from repeated sternotomy is minimized, and manipulation of the diseased ascending aorta is avoided. Morbidity, hospital length of stay, and cost are less than for conventional repeated coronary bypass surgery.
Abstract 162: c-fos Protects the Myocardium from Ischemic Injury and Improves Cardiac Function
Authors: Lu Xiangru , Lei Ming , Xiang Fuli , Feng Qingping
Published: July 2021

Background:
c-fos is an immediate early response gene. c-Fos proteins form heterodimers with Jun family proteins, and the resulting AP-1 complexes regulate transcription by binding to the AP-1 sequence found in many cellular genes. c-fos is activated in cardiomyocytes following myocardial infarction. However, the role of c-fos in regulating cardiomyocyte survival and cardiac function post myocardial infarction (MI) is not known. In the present study, we hypothesized that c-fos protects the myocardium from ischemic injury and improves cardiac function.

Methods and Results:
The generation of mice with cardiomyocyte specific c-fos
−/ −
was achieved by crossing the floxed c-fos mice with mice over-expressing Cre recombinase under the control of α-myosin heavy chain. Wild-type (WT) littermates were used as controls. MI was induced by coronary artery ligation. Infarct size, myocardial apoptosis and cardiac function were determined at 2 days post-MI. While area at risk was similar between the 2 groups, infarct size was significantly increased in c-fos
−/ −
compared to WT mice (58 ± 4% vs. 44 ± 3%,
P<
0.05). Myocardial caspase-3 activity and cytosolic DNA fragments in the peri-infarct region were significantly increased while Bcl-2/Bax protein ratio was significantly decreased in c-fos
−/−
mice (
P<
0.05). LV pressure volume relationship was assessed
in vivo
using a Millar pressure conductance catheter. LV end-systolic elastance ( E
es
) and +d
P
/dt
max
were significantly decreased in c-fos
−/−
compared to WT mice (1.7 ± 0.4 vs. 5.1 ± 1.0 mmHg/μL; 4776 ± 567 vs. 7006 ± 319 mmHg/s,
P<
0.01).

Conclusions:
Deficiency in c-fos increases infarct size and myocardial apoptosis leading to impaired cardiac function post-MI. Our results suggest that c-fos protects the myocardium from ischemic injury and improves cardiac function.
Abstract 565: The Activation of AMP-Activated Protein Kinase Ameliorates the Severity of Heart Failure in Dogs
Authors: Sasaki Hideyuki , Asanuma Hiroshi , Fujita Masashi , Takahama Hiroyuki , Wakeno Masakatsu , Asakura Masanori , Kim Jiyoong , Minamino Tetsuo , Komamura Kazuo , Mochizuki Naoki , Kitakaze Masafumi
Published: July 2021

Backgrounds;
Since AMP-activated protein kinase (AMPK) is activated in the pressure-overloaded hypertrophic hearts, we investigated whether the activation of AMPK caused by metformin attenuates the progression of heart failure induced by rapid pacing in dogs and decreases cellular damage caused by oxidative stress in neonatal rat cardiac myocytes.

Methods and Results;
Heart failure was induced by right ventricular (RV) pacing at 230 bpm for 4 weeks in dogs. Treatment of dogs with metformin (100mg/kg/day, orally, n=8, Met group) for 4 weeks prevented significantly the progression of pacing-induced heart failure evaluated by echocardiographical and hemodynamic measurement compared with the control group (n=8). Left ventricular (LV) diastolic and systolic dimension (LVDd and LVDs) were smaller (32.8±0.4 and 26.7±0.9 mm, respectively) and fractional shortening (FS) and ejection fraction (EF) were preserved in Met group (18.6±1.8 and 45.5±3.5 %, respectively) compared with the control group (LVDd and LVDs; 36.5±1.0 and 33.0±1.0 mm, FS and EF; 9.6±0.7 and 27.0±1.9 %, p<0.05 vs. Met group each). Furthermore, both pulmonary capillary wedge pressure (PCWP) and mean pulmonary arterial pressure (mPA) were significantly lower in Met group (11.1±0.9 and 18.1±1.4 mmHg, respectively) compared with the control group (21.0±2.2 and 26.8±2.8 mmHg, respectively). Treatment of cultured cardiac myocytes with a maximal physiological concentration of metformin (10μmol/L) attenuated the cellular damage against H
2
O
2
exposure (50μmol/L). These effects were blunted by an AMPK inhibitor, compound-C (20μmol/L), suggesting that the activation of AMPK increased the cellular viability during H
2
O
2
exposure.

Conclusions;
Metformin that activates AMPK prevented the progression of heart failure induced by rapid pacing in dogs and attenuated the cellular damage against H
2
O
2
exposure in cardiac myocytes. AMPK may be one of new targets for preventing heart failure in clinical settings.
Abstract 572: Large Solid Organ Perfusion Decellularization - A Start for Human-Sized Tissue Scaffolds?
Authors: Matthiesen Thomas S , Ott Harald C , Goh Sak-Kia , Taylor Doris A
Published: July 2021

Background
. Tissue engineering involves at a minimum cells and scaffold. However, reports of generating human-sized 3-dimensional scaffolds with appropriate architecture are limited. We hypothesize that perfusion decellularization of cadaveric pig solid organs will effectively remove cellular components and DNA, potentially providing a sufficient starting point for whole solid-organ tissue engineering.

Methods
. Adult Yorkshire swine (~60kg) were euthanized after systemic heparinization. Heart, liver, and kidneys were removed and mounted on a perfusion apparatus. Cannulation was performed using either the aorta (heart), portal vein (liver), or renal artery (kidney). Saline at 25C was perfused to remove blood, followed by Sodium Dodecyl Sulfate (SDS) detergent perfusion until tissues were translucent and white in color (heart=40 liters; liver=19 liters; kidney=31 liters). SDS was followed by 2 liters of 1% Triton-X 100 to sequester remaining detergent via micelle formation and clearance. Decellularization was evaluated by histology (H&E, DAPI, IHC). Tissue DNA content post-decellularization was quantified using a Hoechst-33258 DNA assay.

Results
. By histology, heart, liver, and kidney lacked intracellular components and DAPI, but retained major ECM proteins (fibronectin, collagen, and laminin). DNA in decellularized tissue was <2.2% of cadaveric controls by wet weight for all organs (heart=16.0 ± 2.9 vs. control=762.6 ± 48.5 ng/mg; liver=3.6 ± 0.7 vs. control=1157.6 ±91.7 ng/mg; kidney=25.2 ± 1.7 vs. control=1380.0 ± 201.2 ng/mg).

Conclusion
. SDS-based perfusion decellularization of large animal organs is effective at removing cellular content and DNA. The remaining whole-organ scaffold provides a platform technology for a novel construct for tissue engineering of human sized bioartificial organs.
Abstract 598: Deletion of Microsomal PGE Synthase-1 Decreases Oxidative Stress and Protects Against Abdominal Aortic Aneurysm Formation in Angiotensin II-Infused Mice
Authors: Wang Miao , Stubbe Jane , Lee Eric , Song Wenliang , Ricciotti Emanuela , Puré Ellen , FitzGerald Garret A
Published: July 2021

Microsomal (m) prostaglandin (PG) E
2
synthase(S)-1, an enzyme that catalyzes the isomerization of the cyclooxygenase (COX) product, PGH
2
, into PGE
2
, is a major source of PGE
2
in vivo
. mPGES-1 deletion in mice was found to modulate experimentally evoked pain and inflammation and atherogenesis is retarded in mPGES-1 knockout (KO) mice. The impact of mPGES-1 deletion on formation of angiotensin II (Ang II)-induced abdominal aortic aneurysms (AAA) was studied in mice lacking the low density lipoprotein receptor (LDLR
−/−
). AngII infusion increased aortic macrophage recruitment and nitrotyrosine staining while upregulating both mPGES-1 and COX-2 and urinary excretion of the major metabolite of PGE
2
(PGE-M). Deletion of mPGES-1 decreased both the incidence and severity of AAA and depressed excretion of both PGE-M and 8, 12-iso-iPF
2a
-VI, which reflects lipid peroxidation
in vivo
. While Ang II infusion augmented prostaglandin biosynthesis, deletion of mPGES-1 resulted in rediversion to PGD
2
, reflected by its major urinary metabolite. However, deletion of the PGD
2
receptor, DP1, did not affect AAA in Ang II infused LDLR
−/−
mice. These observations indicate that deletion of mPGES-1 protects against AAA formation by AngII in hyperlipidemic mice, perhaps by decreasing oxidative stress. Inhibition of mPGES-1 may represent an effective treatment to limit aneurysm occurrence and expansion.
Abstract 169: Activation of the Phosphoinositide 3-Kinase/Akt Pathway is Responsible for Cardioprotection Induced by Modulation of TLR2
Authors: Li Chuanfu , Hua Fang , Ha Tuanzhu , Ma Jing , Kelley Jim , Browder I W , Kao Race L , Williams David L
Published: July 2021

Activation of the phosphoinositide-3 kinase/Akt (PI3K/Akt) signaling pathway protects cells from ischemic injury. We have reported that the immune modulator, glucan, rapidly induces cardioprotection. Dectin-1 is a specific receptor for glucan and Toll-like receptor 2 (TLR2) is required for transmitting the signal from Dectin-1 into cells. However, the role of modulation of TLR2 in cardioprotection has not been investigated. We hypothesized that modulation of TLR2 will induce cardioprotection through a PI3K/Akt-dependent mechanism. To evaluate our hypothesis, we examined the effect of modulation of TLR2 on myocardial ischemic injury. TLR2 knockout (KO) (n=8) and wild type mice (n=8) were treated with glucan (1 mg/25g) or peptidoglycan (PDG, 75 μg/25g), a specific TLR2 ligand, one hr before the hearts were subjected to ischemia (1 hr)/reperfusion (4 hrs). Untreated mice (n=8) were also subjected to I/R. Myocardial infarction was determined by TTC staining. Infarct size was significantly reduced in glucan (11.6 ± 2.38% vs 36.1 ± 3.48%, p<0.01) and PDG (10.5 ± 3.03% vs 30.1 ± 7.59%, p<0.01) treated mice vs untreated mice. The levels of phospho-Akt (0.80 ± 0.10 vs 0.45 ± 0.09) and phospho-GSK3β (0.66 ± 0.14 vs 0.33 ± 0.10) were significantly increased in the myocardium of glucan treated mice compared with untreated mice. However, both glucan and PDG-induced cardioprotection were completely abolished in TLR2 KO mice. To investigate whether PI3K/Akt signaling is involved in cardioprotection induced by modulation of TLR2, we administered glucan (1 mg/25g) or PDG (75 μg/25g) to kdAkt (kinase deficient Akt) transgenic mice (n=8) one hr before myocardial I/R. Both glucan and PDG-induced cardioprotection were completely abolished in kdAkt mice. The results suggest that modulation of TLR2, either directly or indirectly, will induce cardioprotection through a PI3K/Akt dependent mechanism and that there is a critical link between TLR2 and PI3K/Akt signaling during myocardial I/R.
Abstract 615: LKB1 is Required for Statin-induced Activation of the AMP-activated Protein Kinase
Authors: Choi Hyoung Chul , Zhang Miao , Xie Zhonglin , Zou Ming-Hui
Published: July 2021

Statins, lipid-lowering drugs, exert many beneficial effects on the cardiovascular system. Recent studies have demonstrated that clinically relevant concentrations of statins might exert their therapeutic effects by activating the AMP-activated kinase (AMPK) in cultured endothelial cells, but the mechanism remains elusive. The aim of the study was to determine the molecular mechanism by which statins activate AMPK. Confluent bovine aortic endothelial cells (BAEC) were exposed to simvastatins for 1 to 24 h. Exposure of BAEC to simvastatins caused a time-dependent and dose-dependent increase of AMPK-Thr172 phosphorylation. In parallel, simvastatins significantly increased the phosphorylation of both LKB1 at serine 428 and protein kinase C (PKC)-ζ at Thr410/403. Further, adenoviral overexpression of LKB1 kinase-dead (LKB1 D194A) mutants, but not adenoviruses encoding green fluorescence proteins (GFP), ablated simvastatin-induced AMPK-Thr172 phosphorylation, suggesting LKB1 is required for statin-enhanced AMPK activation. Conversely, neither inhibition of calcium calmodulin-dependent kinase kinase (CaMKK) with STO609 (1 μM), a CaMKK-specific inhibitor, nor transfection of CaMKK-specific siRNA altered simvastatin-enhanced AMPK Thr172 phosphorylation, suggesting that CaMKK is not required for statin-enhanced AMPK activation. Moreover, overexpression of PKC-ζ dominant negative mutants or PKC-ζ-specific siRNA abolished simvastatin-enhanced phosphorylation of both LKB1-Ser428 and AMPK-Thr172, implying that PKC-ζ is the upstream enzyme of LKB1. Finally, compared to lean mice, the phosphorylation of both AMPK-Thr172 and LKB1-Ser428 was significantly suppressed in the hearts and livers of diabetic DB/DB mice (n=4 or 6, p<0.05). Treatment of diabetic DB/DB mice with fluvastatin (22.5 mg/kg/day in drinking water) for 4 months significantly increased the levels of total AMPK as well as AMPK-Thr172 phosphorylation in the livers and hearts of DB/DB mice. In addition, fluvastatin significantly increased detection of LKB1-Ser428 phosphorylation. We conclude that statins increase AMPK activation by increasing PKC-ζ-dependent LKB1 phosphorylation at Ser428
in vivo
.
Abstract 626: Shear Stress Regulates Angiotensin Type One Receptor Expression in Endothelial Cells
Authors: Ramkhelawon Bhama , Vilar Jose , Tedgui Alain , Stephanie Lehoux
Published: July 2021

Several studies have shown that angiotensin II tends to favour atherosclerotic lesion formation and progression, acting mainly through angiotensin type one receptors (AT1R). Conversely, shear stress (SS) confers atheroprotective effects in the vasculature. However, whether SS regulates endothelial AT1R expression remains unknown. Using en face staining of C57BL/6 mouse aortas, we found a pronounced expression of AT1R in the inner regions of the aortic arch and at collateral artery branch points, known to have low flow and to be atheroprone, compared with neighboring high SS regions. Furthermore, staining of vessels from hypercholesterolemic LDLR−/−mice demonstrated a clear expression of AT1R only in endothelium overlying plaques. Using HUVECs exposed to a laminar SS of 15dynes/cm2, we observed a biphasic decrease in AT1R protein expression characterized by a first reduction at 1 hr (31+4% of static control, p<0.001), partial recovery at 3 hr (65+9%), and a second more prolonged decrease at 6, 12 and 24 hrs (48+9%, 36+9%, 33+5% of static control, respectively)(p<0.001). AT2R levels remained unchanged in these conditions. Shear-induced downregulation of AT1R was abolished by treatment with L-NAME (10–7M), suggesting that NO regulates AT1R in sheared endothelial cells. In accordance, stimulating static HUVECs with a NO donor for 1 hour decreased AT1R protein expression. The acute loss of AT1R at 1 hour SS suggested a rapid endocytosis and degradation of the protein. Indeed, immunocytochemical staining demonstrated a clear colocalisation of AT1R with caveolin-1 in HUVECs submitted to 5 mins SS, similar to that observed in angII-stimulated cells. Cholesterol depletion with methyl-beta-cyclodextrin prevented AT1R-caveolin colocalisation. No colocalisation of AT1R with clathrin was observed. In comparison, AT2R did not undergo endocytosis under any conditions tested. Finally, RT-PCR revealed a significant (p<0.001) decrease of AT1R mRNA in HUVECs exposed to SS during 6 (4+1% of static control), 12 (4+1%) and 24 hours (15+4%), suggesting a transcriptional downregulation of AT1R at length. Hence, our results demonstrate that SS may convey some of its atheroprotective effects through degradation and downregulation of AT1R in endothelial cells.
Abstract 637: A Pharmacogenetic Screen for Modifiers of Drug Induced QT Prolongation Reveals 15 Novel Genes.
Authors: Milan David J , Jones Ian L , Amsterdam Adam H , Rosenbaum David S , Roden Dan , MacRae Calum A
Published: July 2021

Introduction:
Variability in response to therapeutic drugs is a vexing problem that has recently begun to yield to intense investigatory efforts. Rigorous pharmacogenetic studies will require model systems that recapitulate the complexity of individual drug responses.

Methods:
We have employed the voltage sensitive fluorescent dye di 4-ANEPPS and high speed CCD camera acquisition to study cardiac repolarization in embryonic zebrafish. We used a known zebrafish KCNH2 mutant, anemone toxin II (ATXII) and dofetilide to perturb cardiac repolarization. We also undertook a screen of a known panel of 294 mutant zebrafish lines to identify genes that modify the response to IKr block.

Results:
Using optical mapping, we demonstrate action potential prolongation (Figure 1a,b

), reduced repolarization reserve (Figure 1d

), and spontaneous early afterdepolarizations in zebrafish harboring a mutation in KCNH2. We also show that augmentation of late sodium current using anemone toxin II prolongs action potential duration (Figure 1c

). Using this model we have conducted a pharmacogenetic screen for modifiers of drug-induced QT prolongation, and have identified 15 genes that modulate the response to IKr block, including three members of the
heg-san-vtn
pathway.

Conclusion:
Together these data implicate a complex network of non-ion channel proteins functioning in membrane microdomains to regulate channel function, and validate high-throughput screening in zebrafish to dissect complex biologic systems.
Abstract 653: Muscle Ring Finger-1 (MuRF1) Expression Shifts Cardiomyocyte Substrate Utilization from Fatty Acids to Glucose
Authors: Willis Monte S , Schisler Jon , McDonough Holly , Patterson Cam
Published: July 2021

Previous work has suggested that MuRF1, a cardiac-specific protein, regulates metabolism by its interactions with proteins that regulate ATP transport, glycolysis, and the electron transport chain. We recently identified that MuRF1 is cardioprotective in ischemia reperfusion injury. In the current study, we investigated the effects of MuRF1 expression on metabolic substrate utilization and found that MuRF1 shifts substrate utilization from fatty acids to glucose in a dose-dependent manner. Isolated neonatal ventricular cardiomyocytes were treated with an adenovirus expressing MuRF1 (Ad.MuRF1) or GFP (Ad.GFP) at a range of 0–25 MOI (Multiplicity Of Infection). 14C-Oleate or 14C-glucose were added to cells for 1 hour and 14C-CO2 release was determined using the CO2-trapping method. Trapped 14CO2 and acid soluble metabolites were used to calculate total fatty acid oxidation. Cardiomyocytes treated with 5–25 MOI Ad.MuRF1 demonstrated a dose dependent decrease in fatty acid oxidation of 10.5 +/− 2.3(5 MOI), 8.5 +/− 1.9 (10 MOI), 6.6 +/− 1.6 (15 MOI), and 5.1 +/− 1.3 (25 MOI) nmol oleate/mg protein/h. Compared with control cardiomyocytes treated with 5–25 MOI Ad.GFP (average of 5–25 MOI=13.5 +/− 0.7 nmol oleate/mg protein/h), this represents a 22.2%– 62.2% decrease in fatty acid oxidation. Inversely, glucose oxidation increased with increasing MuRF1 expression. Cardiomyocytes infected with 25 MOI Ad.MuRF1 oxidized 184% more glucose (28.9 +/− 4.6 nmol glucose/mg protein/h) compared to control cells treated with 25 MOI Ad.GFP (15.7 +/− 1.3 nmol glucose/mg protein/h). Increasing MuRF1 expression resulted in no net gain or loss of calculated ATP production (1699 +/− 157 vs. 1480 +/− 188 nmol ATP/mg protein/h). The co-utilization of glucose and fatty acids as substrates for the production of ATP allows the heart to adapt to both environmental stress and disease. Increasing the relative proportion of glucose oxidation in relationship to fatty acids is a known protective mechanism during cardiac stress, and may represent one mechanism by which MuRF1 is cardioprotective.
Abstract 661: The K
ATP
-channel Opener, Nicorandil, Attenuates Monocrotaline-induced Endothelial Damage in Pulmonary Vasculature through the Enhanced Expressions of eNOS and Anti-apoptotic Factors via PI3K/Akt and MAPK pathways
Authors: Sahara Makoto , Sata Masataka , Morita Toshihiro , Hirata Yasunobu , Nagai Ryozo
Published: July 2021

Background:
Recent evidence suggests that nicorandil, a K
ATP
channel opener, reveals a number of beneficial cardiovascular actions; however, its effects on pulmonary vasculature in the context of pulmonary hypertension (PH) have not yet been elucidated.

Methods and Results:
Sprague-Dawley rats injected with 60 mg/kg monocrotaline (MCT)-IP were randomized to receive either vehicle, nicorandil (2.5–7.5 mg/kg/day), nicorandil +glibenclamide (a K
ATP
channel blocker), nicorandil +
L-
NAME (a NOS inhibitor), or ZVAD-fmk (a caspase inhibitor; 3.3 mg/kg-IV). After 28 days, the increased right ventricular systolic pressure in vehicle-group (51.6 ± 4.4 mmHg) was significantly attenuated by nicorandil in a dose-dependent manner (33.6 ± 4.5 mmHg in Nico
7.5-
group; p<0.05) or ZVAD-fmk (32.2 ± 3.1 mmHg; p<0.05). Nicorandil and ZVAD-fmk protected pulmonary endothelium from MCT-induced damage and apoptosis via the enhanced expression of eNOS in lungs, followed by inhibition of both thromboembolic formation in pulmonary microcirculation and medial wall thickening in pulmonary arterioles. These beneficial effects by nicorandil were markedly prevented by coadministration of glibenclamide or
L-
NAME. Next, HUVECs were incubated in the absence or presence of nicorandil (100 μM) or another K
ATP
channel opener, diazoxide. TUNEL staining and the MTS assay revealed that HUVECs in serum-free medium displayed apoptosis, which was attenuated by both nicorandil and diazoxide. To study the signaling pathways implicated in the nicorandil-stimulated protective responses, we determined the phosphorylation status of Akt and ERK1/2. Incubation of HUVECs with nicorandil increased both Akt and ERK1/2 phosphorylation in a time-dependent manner. In addition, nicorandil upregulated the protein levels of eNOS and an apoptosis inhibitor, Bcl-2 in HUVECs. These effects by nicorandil on HUVECs were blocked by coadministration of glibenclamide,
L-
NAME, LY294002 (a PI3K inhibitor), or PD98059 (a MEK inhibitor), respectively.

Conclusions:
Nicorandil attenuates MCT-induced endothelial damage in pulmonary vasculature through the enhanced expressions of eNOS and anti-apoptotic factors via PI3K/Akt and MAPK pathways. Nicorandil may have a therapeutic potential for PH.
Abstract 682: Lapaqistat Acetate Monotherapy: Effects of a Novel Squalene Synthase Inhibitor on LDL-C Levels and Other Lipid Parameters in Patients with Primary Hypercholesterolemia
Authors: Bays Harold E , Weiss Robert J , Rhyne James M , Chen Yinzhong , Lopez Claudia , Spezzi Andrea H
Published: July 2021

Background:
Lapaquistat acetate (LAPA) inhibits squalene synthase, an important enzyme in the cholesterol biosynthetic pathway. Early studies showed that LAPA reduced LDL-C and improved lipid profiles in animals and humans.

Methods:
This multicenter, phase III, randomized, double-blind, parallel-group, placebo-controlled study assessed LAPA monotherapy in nondiabetic patients ≥ 18 yrs old with primary hypercholesterolemia (mean LDL-C > 130 mg/dL and < 220 mg/dL; mean triglyceride [TG] ≤400 mg/dL). Treatment-naïve patients or patients discontinuing previous lipid-lowering therapy underwent a 6-wk dietary stabilization period, then were randomized to 100 mg LAPA (n = 241) or Placebo (n = 120) once daily for 12 wks. The primary endpoint was percent (%) change from baseline compared with Placebo in direct LDL-C at Wk 12 or last on-treatment value. Secondary endpoints included: % change in calculated LDL-C, non-HDL-C, total cholesterol (TC), Apo B, HDL-C, VLDL-C, Apo A1, TG, and hs-CRP. Safety was monitored using clinical and laboratory examinations.

Results:
LAPA significantly reduced LDL-C levels (see Table

) within 2– 4 wks of treatment initiation that were maintained throughout the study. LDL-C remained relatively unchanged in the Placebo group. Compared with Placebo, LAPA lowered LDL-C levels 20.09% by end of study (p < 0.001). Non-HDL-C, TC, Apo B, VLDL-C, Apo A1, TG, and hs-CRP were also significantly reduced vs Placebo. Both the overall adverse event (AE) profile and the rate of AEs considered potentially related to study drug (~24%), were similar between treatment groups. Two serious AEs occurred in each group; the 2 SAEs in lapaquistat-treated patients were considered not related to study drug.

Conclusion:
LAPA (100 mg/day) monotherapy provided significant improvements in LDL-C, non-HDL-C, TC, Apo B, VLDL-C, TG, and hs-CRP levels, was generally safe and well tolerated, and potentially represents a novel treatment for hypercholesterolemic patients.