bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3191: Experimental Validation Using Radiolabeled Microspheres of Absolute Quantitation of Regional Myocardial Blood Flow (MBF) Using Dynamic Rb-82 Positron Emission Tomography (PET)
Authors: El Fakhri Georges , Mekkaoui Choukri , Sitek Arkadiusz , Dione Donald P , Carson Richard E , Brennan Matthew , Di Carli Marcelo F , Sinusas Albert J 
Published: July 2021

Absolute quantitation of MBF with dynamic Rb-82 PET has great potential in the assessment of the extent and severity of ischemia in patients with suspected coronary artery disease, particularly at centers that lack access to a cyclotron, but requires validation of MBF estimation.
METHODS: In order to validate our automated Rb-82 PET MBF quantitation based on generalized factor and compartment analyses (GFADS), we compared rest/stress regional Rb-82 MBF to reference MBF measured with radiolabeled microspheres (MS) in 6 dogs before and after creation of a critical LAD stenosis. High resolution dynamic Rb-82 PET acquisitions were performed on a Siemens HRRT in 3D listmode at rest and during adenosine stress in conjunction with injection of MS. Studies were rebinned into 24 5-sec, 6 10-sec, and 4 20-sec frames, and reconstructed using OSEM, compensating for scatter, randoms, attenuation and resolution. Hearts were cut into 5 mm slices (8 radial segments per slice). Myocardial segments were re-mapped to match the 17 segments of the standard polar map. Left and right ventricle input functions were automatically computed using GFADS. LV input was validated with on-line measurements of arterial activity. Polar maps of MBF (K1, ml/g/min) and coronary flow reserve (CFR) were computed using a 2-compartment kinetic model yielding 34 segments at rest and stress for each dog, that were remapped into apical, mid and basal ischemic and non-ischemic territories.
RESULTS: MBF (uncorrected by RPP) derived from dynamic PET were in reasonable agreement with MS values at rest: MBF (PET) = 0.38 x MS + 0.39, r= 0.70, and in good agreement with MS values at stress: MBF(PET) = 0.48 x MS + 0.22; r=0.86. Regional CFR derived from dynamic PET was also in good agreement with MS values in the normal LCX territory (PET:1.44Â±0.17 vs MS:1.53Â±0.14) as well as in the LAD territory where a stenosis was created (1.07Â±0.18 vs. 1.17Â±0.16). PET and MS CFR values correlated well over the range of 0.51–2.37: CFR(PET) = 0.796 x MS + 0.421; r=0.940.
CONCLUSION: Absolute quantification of MBF and CFR can be obtained from dynamic rest/stress Rb-82 PET using a fully automated GFADS approach which was validated in experimental animals using MS flow and should permit rapid determination of absolute MBF in patients.
Abstract 436: The Fat1 Cadherin Intracellular Domain Interacts with Atrophin Proteins and Recruits Robust Transcription Activity
Authors: Hou Rong , Sibinga Nicholas 
Published: July 2021

Background: We recently reported that the atypical cadherin Fat1 is strongly induced after arterial injury, inhibits growth and promotes migration of vascular smooth muscle cells (VSMCs), and can undergo cleavage, with subsequent translocation of its intracellular domain (Fat1IC) to the cell nucleus. In Drosophila, dFat and Atrophin, a nuclear receptor transcriptional corepressor implicated in the control of cell polarity and migration, have been linked by both physical and genetic interaction. Together, these findings suggest an important integrative role for Fat1 in active vascular remodeling, and raise the possibility that some Fat1 effects are mediated from the nucleus via interaction with transcriptional regulators.
Objectives, methods, findings: We hypothesized that the interaction of mammalian Fat1IC with nuclear proteins, such as the mammalian Atrophin homologues atro-1 and atro-2, might contribute to the phenotypic effects of Fat1 on VSMC activation. To test for such interactions, we performed co-immunoprecipitation and Western analysis, identified a physical interaction of Fat1 with atro-1 and atro-2, and mapped necessary Fat1IC sequences to a discrete domain. Immunocytochemical staining showed partial co-localization of Fat1 and atro-1 and -2 in the nucleoplasm. In mammalian two-hybrid assays, surprisingly, tethering of the Fat1IC to DNA yielded very robust transcriptional activation, not repression. This activity was augmented by COUP-TFs, orphan nuclear receptor transcription factors known to associate with atrophins and implicated in both angiogenesis and cardiac development, but not previously linked to Fat1. The biological relevance of these interactions is further supported by quantitative PCR analysis that showed induction of both atro-1 and atro-2 mRNAs after vascular injury, similar to the pattern we identified for Fat1.
Conclusion: The biological significance and molecular functions of the multiple cadherin superfamily proteins expressed in VSMCs are not well understood. Our studies demonstrate the physical and functional interaction of the Fat1IC with multiple nuclear proteins involved in transcriptional regulation, and point to novel pathways by which Fat1 may affect VSMC growth and migration.
Abstract 3226: The “Single-Big-Cryo-Balloon” Technique for Pulmonary Vein Isolation - A New Ice Age?
Authors: Chun Julian , Antz Matthias , Ouyang Feifan , Satomi Kazuhiro , Bansch Dietnar , Tilz Roland , Zerm Thomas , Kuck Karl-Heinz 
Published: July 2021

Background: Cryothermal-energy (CTE) applied via a balloon catheter (Arctic Front, Cryocath) represents a novel technology which may facilitate accomplishing the challenging endpoint of complete electrial pulmonary vein isolation (PVI). However, as in all balloon based PVI approaches, phrenic nerve (PN) injury remains a concern. Therefore, we pursued the ,,single big cryo-balloon technique“ deploying proximal (antral) CTE to

achieve complete electrical PVI and

avoid PN palsy in patients (pts) with paroxysmal atrial fibrillation (PAF).

Methods: After double transseptal punctures one lasso catheter and the big 28 mm Cryo-balloon catheter (10.5 F) using a steerable sheath (15F) were inserted into the left atrium (LA). PV angiographies and ostial lasso recordings from all PVs were obtained. Selective PV occlusion angiographies were used to evaluate balloon to LA-PV junction contact. One CTE freezing cycle lasted 300 seconds. To early identify PN injury, the PN was constantly paced (10 V, 2.9 ms) from the superior caval vein while applying energy at the right superior PV (RSPV). Follow up included weekly telephonic interviews, holter ECGs, office visits after 1, 3 and 6 months and additional daily tele ECGs.
Results: Twenty-six pts (18 males, mean age: 56 ± 9, LA size: 41.5 ± 5.2) with highly symptomatic paroxysmal atrial fibrillation (mean duration: 6.7 ± 5.8 years) despite antiarrhythmic drug therapy (3 ± 1) were included in this study. Complete electrical PV isolation was achieved in 93/95 PVs (98%) using exclusively the big balloon technique. Mean procedural-, balloon- and fluoroscopy-time were 239 ± 99, 135 ± 66, and 56 ± 22 min, respectively. One persistent PN palsy occurred due to an unanticipated ablation inside the RSPV (inner balloon defect). A total of 17 pts (62 %) remained in sinusrhythm during a mean follow up of 142 ± 114 days.
Conclusion: Using exclusively the “single big cryo-balloon” technique, the vast majority of all PVs (98%) can be electrically isolated resulting in an acceptable clinical success rate after one procedure. PN palsy is avoided as long ablation is performed at the proximal LA-PV junction.
Abstract 3336: Fractional and Coronary Flow Reserve in Prediction of Functional Recovery of Myocardium in Patients with Previous Myocardial Infarction
Authors: Beleslin Branko , Ostojic Miodrag , Djordjevic-Dikic Ana , Vukcevic Vladan , Stojkovic Sinisa , Nedeljkovic Milan , Stankovic Goran , Orlic Dejan , Stepanovic Jelena , Giga Vojislav , Arandjelovic Aleksandra 
Published: July 2021

Background: Fractional flow reserve (FFR) may provide clinically useful diagnostic information both in patients (pts) with normal left ventricular (LV) function as well as in pts with previous myocardial infarction (MI). However, the question remains to the relation between improvement of FFR and improvement of LV function in pts with previous MI undergoing percutaneous coronary intervention (PCI).
Aim: The aim of the study was to evaluate the relation between FFR and simultaneously evaluated coronary flow reserve by thermodilution (CFRthermo), with functional improvement of LV function in pts with previous MI undergoing PCI.
Methods: Study population consisted of 50 pts (mean age 53±8 years; 40 male) with previous MI and significant coronary stenosis in one-vessel CAD (33 LAD, 4 Cx, 13 RCA) undergoing PCI of infarct-related coronary artery. In all pts we have evaluated by single pressure/thermo wire FFR and CFRthermo before and immediately after PCI. In all pts, we have evaluated LV ejection fraction by echo and wall motion score index (WMSI) before and 3 months after PCI.
Results: Coronary lesions were successfully treated in all pts with decrease of diameter stenosis from 63±7% to 18±9% (p<0.001). FFR increased significantly (p<0.001) from 0.62±0.15 to 0.91±0.06 after PCI, whereas CFRthermo increased significantly (p<0.01) from 1.5±0.3 to 2.5±0.7. LV ejection fraction increased from 49±6% to 55±8% (p<0.0001), and WMSI decreased from 1.44±0.24 to 1.29±0.29 (p<0.0001). LV functional improvement was observed in 33/50 (66%) of pts. In pts with LV functional recovery in comparison to pts with no recovery there was significant difference in FFR before PCI (0.57±0.15 vs. 0.71±0.11, p=0.001), improvement of FFR during PCI (0.34±0.15 vs. 0.21±0.13, p=0.004), improvement of CFRthermo during PCI (1.2±0.6 vs. 0.6±0.5, p=0.001) and CFRthermo after PCI (2.7±0.7 vs. 2.1±0.6, p=0.008), respectively.
Conclusion: Evaluation of FFR and CFRthermo provide significant prognostic information on LV functional recovery in pts with previous MI undergoing PCI. Lower FFR before PCI, higher CFRthermo after PCI, as well as higher improvement of FFR and CFRthermo during PCI are indicative of left ventricular functional improvement in pts with previous MI.
Abstract 3367: Prospective Testing of Isoproterenol and Adenosine After Pulmonary Vein Isolation: Acute Results
Authors: Callahan Thomas D , Zakaib John S , Meulet John , Barrett Conor , Phillips Karen , Wasson Sanjeev , Elayi Claude , Ching Chi Keong , Dresing Thomas , Schweikert Robert , Martin David , Burkhardt J D , Cummings Jennifer , Wazni Ousama , Kanj Mohamed , Saliba Walid , Natale Andrea 
Published: July 2021

Background: Pulmonary vein isolation (PVI) offers an estimated cure rate from atrial fibrillation (AF) of 60 to 80% after the first procedure. While some data suggest that lack of inducibility of AF by electrical stimulation after atrial fibrillation ablation may predict improved outcomes, chemical induction of AF during PVI has not been well-studied. In an on-going prospective study, we seek to determine if chemical induction of AF after PVI with subsequent ablation of elicited triggers improves overall success. Herein, we report acute results of attempted re-induction of AF using adenosine and isoproterenol in patients undergoing PVI.
Methods: Fourty-three consecutive patients with symptomatic AF presented for PVI. Following initial isolation and while catheters were still in place in the left atrium, 18 to 24 mg of IV adenosine was administered as a single bolus. Subsequently, infusion of isoproterenol was administered at up to 20 mcg/min. After administration of each drug, patients were observed for induction of AF or other atrial arrhythmias, focal firing including frequent monomorphic PAC’s or focal atrial tachycardias or evidence of recovery of conduction from the pulmonary veins.
Results: Adenosine administration induced atrial fibrillation in 3 of 43 patients. Notably, no arrhythmias or focal firing were seen with isoproterenol in these three patients. Adenosine did not uncover recovery of conduction from the pulmonary veins in any patient or induce focal firing. Isoproterenol administration induced atrial fibrillation in 3 patients. Focal firing was induced in 18 patients. Recovery of conduction into pulmonary veins was observed after isoproterenol in 6 of 43 patients resulting in application of additional lesions to achieve re-isolation in each case.
Conclusions: Our initial data suggests atrial fibrillation may be chemically re-induced with adenosine and isoproterenol administration in a minority of patients undergoing PVI. Focal firing may also be induced with isoproterenol. Isoproterenol but not adenosine uncovered recovery of conduction into the pulmonary veins in several patients. The mechanism by which arrhythmias and AF initiate may differ with adenosine versus isoproterenol.
Abstract 3387: The Effects of Restrictive Annuloplasty on Mitral Leaflet Coaptation and The Mechanism Regulating Functional Mitral Regurgitation: Simplified Echocardiographic Study
Authors: Shudo Yasuhiro , Taniguchi Kazuhiro , Toda Koichi , Matsue Hajime , Hata Hiroki , Fujita Shinichi 
Published: July 2021

Objectives: The effects of restrictive annuloplasty on mitral leaflet coaptation in a clinical setting have not been fully elucidated. We developed a novel simplified method for assessing the actual degree of coaptation and investigated changes caused by its use. Based on our findings, we evaluated the direct effects of restrictive annuloplasty on mitral leaflet coaptation and the mechanism regulating mitral regurgitation.
Methods and Results: We studied 23 patients (mean 60 years old) with functional mitral regurgitation (grade 3 to 4+) with congestive heart failure (LV ejection fraction 32±10%) due to idiopathic (n=8) or ischemic (n=15) who underwent mitral valve repair with restrictive annuloplasty and 20 normal control subjects. We measured the septal-lateral diameter, tenting height, tenting area, and coaptation length of the mitral valve in 4-chamber, 2-chamber, and long-axis views at mid-systole before and after surgery using transthoracic and transesophageal echocardiography procedures. Coaptation length was calculated with the following formula: Ad-Ac, where Ad equals the whole length of the anterior leaflet during the diastolic phase and Ac equals the length of the non-coaptation free portion of the anterior leaflet at mid-systole. Coaptation length index was defined as the ratio of coaptation length to septal-lateral diameter.

Results: Tenting height and tenting area were significantly decreased, while coaptation length and coaptation length index were significantly increased (Table

). In multivariate analysis, coaptation length index showed a statistically significant negative correlation with degree of residual MR (r=0.77, p<0.0001) and was found to be the most reliable predictor of MR grade.

Conclusion: Our novel simplified method provided quantitative and morphological descriptions of mitral leaflet coaptation, and can also provide important information for developing a surgical strategy for regulation of MR.

Table
Abstract 3403: Heart Failure Patients Improve their Exercise Capacity after Cardiac Rehabilitation Irrespective of having a Preserved or Depressed Ejection Fraction
Authors: Franco Veronica , Brown Todd M , Tallaj Jose A , Sanderson Bonnie , Bittner Vera A 
Published: July 2021

Background: Whether exercise training reduces morbidity and mortality in heart failure (HF) patients is unknown. The objective of this study was to determine if cardiac rehabilitation (CR) outcomes differ in HF patients with and without systolic dysfunction.
Methods: We included the 152 patients completing CR from 1996 to 2006 with HF listed as the primary diagnosis or as a co-morbidity. Based on left ventricular ejection fraction (LVEF) at enrollment, we divided patients into 2 groups: those with LVEF ≥ 45% (51/152, 34%) and those with LVEF < 45% (101/152, 66%). At baseline, we compared distance, perceived exertion (Borg Scale), shortness of breath (Dyspnea Scale), and maximum heart rate (MHR) during a 6 minute walk test (MWT);self reported physical activity (total metabolic hours); depressive symptoms (Beck Depression Inventory [BDI]); and quality of life (physical component score [PCS] and mental component score [MCS] of the SF-36) between the 2 groups. Within each group, we compared changes from baseline to CR completion for each parameter. We compared differences between groups with multivariate linear regression to assess the association between LVEF classification and changes in each parameter, controlling for age, race, gender, and baseline value of the parameter.

Results: Mean age (61 vs. 62 years), race (43% vs. 43% non-white), and gender (36% vs. 37% women) were similar in the 2 groups. At baseline, both groups had similar 6 MWT values, depressive symptoms, and quality of life, although Borg scores were higher in the LVEF ≥ 45% group. At CR completion, the 2 groups showed improvement in all parameters (all p<0.05) except MHR on 6 MWT, which was unchanged in both groups. After adjusting for age, race, gender, and baseline value of each parameter, there was no difference in the magnitude of the improvement between the 2 groups (table

).

Conclusions: Patients with clinical heart failure symptoms, regardless of ejection fraction, benefit from exercise training.
Abstract 3497: Low Serum Estradiol and Cardiovascular Disease Mortality in Older Men: The Rancho Bernardo Study
Authors: Laughlin Gail A , Barrett-Connor Elizabeth , Bergstrom Jaclyn 
Published: July 2021

Context: The traditional view that the male excess in cardiovascular disease (CVD) mortality is due to harmful effects of testosterone has been challenged. In older men, low, rather than high, testosterone predicts atherosclerotic disease progression, and serum estradiol, not testosterone, is prospectively associated with CVD events.
Objective: To determine the association of endogenous sex hormones with cardiovascular disease mortality in older community-dwelling men.
Methods: Prospective population-based study of 858 men aged 50 to 91 years (median 73) who had serum estradiol and testosterone measurements at baseline (1984 – 87) and were followed for mortality through July, 2006.
Results: Median (95% interval) hormone levels were 300 (175, 505) ng/dl for testosterone and 20 (11, 32) pg/ml for estradiol. During the 22 year (average 12.6) follow-up, 559 deaths occurred; 281 (50%) were due to CVD. Age-adjusted Cox regression analyses using hormone quintiles showed testosterone was not related to CVD mortality, but suggested a threshold effect for lower levels of estradiol (P < .001). The risk of CVD death was 1.77 (95% CI 1.32, 2.38) for men in the lowest estradiol quintile (< 15 pg/ml) compared to those with higher levels (P < .001), adjusting for age, BMI, current smoking, physical activity and alcohol intake. This association was independent of the metabolic syndrome, diabetes and prevalent cardiovascular disease. Additional adjustment for lipids, lipoproteins, blood pressure, insulin resistance, CRP, IL-6, leptin, adiponectin or androgen deficiency (total testosterone < 250 ng/dl) had minimal effect on results. Exclusion of deaths that occurred during the first 2 years (to minimize the effect of occult disease) or adjustment for a combination of health status markers also had no effect. Men with low estradiol had lower BMI, smaller waist girth, and were more likely to have lost 10 pounds in the previous 10 years (all P < .001); adjusting for these factors did not influence results.
Conclusions: Low serum estradiol in older men is associated with increased risk of cardiovascular death, independent of age, adiposity, and lifestyle choices. This relationship does not appear to be due to pre-existing disease and is not related to androgen deficiency.
Abstract 3503: Low Dose Aspirin and Incident Diabetes Mellitus in Apparently Healthy Middle-Aged American Women - the Women’s Health Study
Authors: Pradhan Aruna , Cook Nancy , Manson JoAnn , Ridker Paul , Buring Julie 
Published: July 2021

Introduction: Inflammation is linked with the development of type 2 diabetes. Epidemiologic data suggest this association may be stronger in women and clinical studies demonstrate that short-term high-dose aspirin has a prominent hypoglycemic effect. However, to date, no randomized trials have directly evaluated the efficacy of aspirin in the prevention of type 2 diabetes at doses acceptable for use in routine clinical practice.
Hypothesis: We assessed the hypothesis that treatment with low-dose aspirin reduces the incidence of type 2 diabetes among initially healthy middle-aged American women.
Methods: Subjects were enrolled in the Women’s Health Study, a randomized clinical trial of aspirin and vitamin E for primary prevention of cardiovascular disease and cancer in which subjects were also monitored for the clinical occurrence of type 2 diabetes. Between 1992 and 1995, 38,716 women aged ≥ 45 years and free of diabetes, cancer, and cardiovascular disease were randomized to either low-dose aspirin (100 mg on alternate days) or placebo. During the randomized treatment period (median follow-up = 10 years), 1,696 cases of confirmed clinical type 2 diabetes accrued.
Results: There were 849 cases in the aspirin group and 847 in the placebo group (HR 1.01; CI 1.00 to 1.02). Stratification of the population by diabetes risk factors including age, BMI, physical activity, postmenopausal hormone use, family history of diabetes, and high-sensitivity C-reactive protein levels (n = 27,167) had no effect on this main finding. Analyses accounting for adherence to randomized treatment also failed to show a beneficial effect.
Conclusions: Chronic low-dose aspirin does not prevent the development of type 2 diabetes in apparently healthy middle-aged and older American women.
Abstract 3560: Obstructive Sleep Apnea Exacerbates Endothelial Dysfunction In Patients With Metabolic Syndrome
Authors: Akishita Masahiro , Ohike Yumiko , Hashimoto Masayoshi , Iijima Katsuya , Eto Masato , Teramoto Shinji , Ouchi Yasuyoshi 
Published: July 2021

Background: Both obstructive sleep apnea (OSA) and metabolic syndrome (MS) are well known as the risk factor of cardiovascular diseases, and are prevalent among obese patients. However, whether OSA deteriorates endothelial dysfunction in MS patients has not been determined. We therefore examined flow-mediated vasodilation (FMD) in MS patients with or without OSA.
Methods: We enrolled 49 overweight patients (body mass index ≥25, aged 35–69 years) and categorized into the 3 groups; patients with MS but not OSA (MS group, n=21), Group 2: patients with both MS and OSA (MS+OSA group, n=14), Group 3: patients with no risk factors but overweight (control group, n=14). MS was defined using the IDF criteria and OSA using polysomnography. FMD was measured using ultrasound as the percent change of the brachial artery diameter.
Results: Compared with the control group, MS group showed significantly lower %FMD (6.8±2.4 [mean±SD] vs 5.0±2.7, p<0.001) and HDL cholesterol, and higher triglycerides and hemoglobin A1c. Although there were no significant differences in classical risk factors between MS group and MS+OSA group, %FMD was significantly lower in MS+OSA group than in MS group (3.0±1.3 vs 5.0±2.7, p<0.001). On multiple regression analysis, OSA was significantly related to %FMD, independent of age, body mass index, blood pressure, LDL cholesterol, HDL cholesterol, triglycerides, fasting plasma glucose, and smoking (β=−0.328, p=0.02).
Conclusion: OSA exacerbates endothelial dysfunction in patients with MS, possibly leading to the increased risk of cardiovascular disease.