Publications by authors named "Guido Van Nooten"

Locating the site of increased resistance within the vascular tree in pulmonary arterial hypertension could assist in both patient diagnosis and tailoring treatment. Wave intensity analysis (WIA) is a wave analysis method that may be capable of localizing the major site of reflection within a vascular system. We investigated the contribution of WIA to the analysis of the pulmonary circulation in a rabbit model with animals subjected to variable occlusive pulmonary disease.

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Background: Aortic regurgitation (AR) is a valvular disease that can lead to systolic heart failure. Treatment options besides cardiac surgery are limited and consequently severe AR is associated with higher mortality and morbidity when not operated. In this investigation, we examined the effects of a novel cardiac myosin activator, Omecamtiv-mecarbil (OM), in rats with chronic severe AR.

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Arterial compliance (C) is related to the elasticity, size, and geometrical distribution of arteries. Compliance is a determinant of the load that impedes ventricular ejection. Measuring compliance is difficult, particularly in the pulmonary circulation in which resistive and compliant vessels overlap.

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Background: With more than 15,000 implanted patients worldwide and a survival rate of 80% at 1-year and 59% at 5-years, left ventricular assist device (LVAD) implantation has become an interesting strategy in the management of heart failure patients who are resistant to other kinds of treatment. There are limited data in the literature on the change over time of exercise capacity in LVAD patients, as well as limited knowledge about the beneficial effects that rehabilitation might have on these patients. Therefore, the aim of our study was to evaluate the evolution of exercise capacity on a cohort of patients implanted with the same device (HeartWare) and to analyse the potential impact of rehabilitation.

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Objectives: Concerns have been raised about the durability of the first-generation Mitroflow aortic bioprosthesis (model 12 A-LX) due to the lack of anticalcification treatment. This study reflects a 10-year experience with this prosthesis for aortic valve replacement.

Methods: From June 2003 to May 2012, the Mitroflow prosthesis was used for aortic valve replacement in 510 patients, of whom only 467 with complete clinical follow-up were included for analysis.

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Objectives: To investigate the long-term results of a low international normalized ratio (INR)-anticoagulation program in selected patients after aortic valve replacement (AVR) with the Medtronic Open Pivot mechanical heart valve (OPMHV).

Methods: From January 1993 to December 2012, 909 OPMHV valves were used for single AVR. Patients with preserved sinus rhythm and left ventricular function (Low-INR, n  = 552), were managed to an INR of 1.

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Background: In the pulmonary circulation, there is a linear relationship between systolic pulmonary arterial pressure (SPAP) and mean pulmonary arterial pressure (MPAP). The aim of this study was to determine the passive or active nature of this mechanism by exploring the relationship in patients with and without autonomic rhythm control of the heart and pulmonary circulation.

Methods: Pulmonary arterial pressure recordings from non-transplanted patients and patients with heart transplants or double lung transplants were retrospectively reviewed.

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To date an optimal decellularization protocol of heart valve leaflets (HVL) and pericardia (PER) with an adequate preservation of the extracellular matrix (ECM) is still lacking. This study compares a 4 day Triton X-100-based protocol with faster SDC-based protocols for the decellularization of cardiac tissues. Decellularized and non-treated HVL and PER were processed for histological, biochemical and mechanical analysis to determine the effect of these agents on the structure, ECM components, and biomechanical properties.

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Background: Due to budgetary restrictions our university heart transplant program came to a standstill to be gradually restarted early 2011. Consequently waiting-times for transplantation increased dramatically beyond the usual 10-15 months. We reviewed the clinical results of this peculiar transplant program over the past 4 years.

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Background And Aim Of The Study: Currently, no effective crosslinking reagents are available to treat xenogenic decellularized heart valve matrices. The study aim was to evaluate the crosslinking effect of quercetin, catechin, caffeic acid and tannic acid on porcine aortic valve matrices.

Methods: Cytotoxicity of the different crosslinkers was evaluated.

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Introduction: We describe an unusual durability of a Hancock II porcine bioprosthesis in tricuspid position. Sustainability of bioprostheses is known to be limited especially in young patients.

Presentation Of The Case: A 52-year old Caucasian woman with a history of multiple valve interventions.

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We describe a patient with ascending aorta aneurysm and bovine aortic arch who initially presented with fever. A 65-year-old man with a 2-month history of intermittent fever was referred to our hospital and diagnosed as having a gonococcal ascending aorta aneurysm with penetrating ulcers. He was successfully treated by resection of the ascending aorta and ulcers, replacement of the aortic valve, and prolonged postoperative antibiotic therapy.

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Background: Since May 1992 the Medtronic Open Pivot mechanical heart valve has been implanted routinely at the authors' institution. The study aim was to analyze, retrospectively, the 20-year clinical results of the valve.

Methods: Between May 1992 and December 2011 a total of 1,520 valves was inserted into 1,382 consecutive patients (1,012 aortic, 473 mitral, 26 tricuspid, 9 pulmonary).

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Objectives: The age for correction of tetralogy of Fallot has progressively declined to the postnatal period, often despite an increased rate of transannular patch repair. However, the long-term effect of premature exposure to chronic pulmonary insufficiency on the right ventricle remains unknown. On the basis of the relationship between the duration of pressure overload and age, the role of previous pressure load-related hypertrophy on right ventricular (RV) performance after chronic volume overload was investigated in a porcine model.

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Objectives: We studied a contemporary cohort of adult patients treated surgically for infective endocarditis (IE) in order to evaluate the surgical approach and predictors of outcomes, in relation to the intercurrent adaptation of the 2006 ACC/AHA guidelines.

Methods: One hundred and eighty-six consecutive patients operated on for active IE from August 1999 to September 2012 were reviewed retrospectively. Clinical presentation, surgical management and outcomes in the two study periods before and after January 2007 were compared (Period 1: n = 95 and Period 2: n = 91).

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Background And Aim Of The Study: Platelet gel (PG), a storage vehicle of growth factors, can be considered for the application of growth factors in combination with mesenchymal stem cells (MSCs) to accelerate tissue regeneration. Moreover, the addition of bioactive factors to porcine aortic valves could result in a more rapid repopulation. The study aim was to load acellular porcine aortic valve matrices with the PG-rich growth factors and to evaluate the effect on MSC repopulation.

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Objectives: This study investigates the contribution of infundibular versus pulmonary valve (PV) dysfunction on right ventricular (RV) function in a porcine model.

Background: Clinical outcome after repair of tetralogy of Fallot is determined by the adaptation of the right ventricle to the physiological sequelae of the right ventricular outflow tract (RVOT) reconstruction. Recent surgical techniques are pursuing a PV-versus infundibulum-sparing approach.

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The aim was to describe how to avoid technical difficulties during venous femoral cannula insertion for extracorporeal membrane oxygenation (ECMO) in a woman in late pregnancy. A 28-year old pregnant woman presented at 32 weeks of gestation after developing an acute respiratory distress syndrome (ARDS) of an unknown origin that required venovenous ECMO insertion via the femoral vein. A cannula insertion by the Seldinger visual control technique was impossible in the supine position.

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Background And Aim Of The Study: Since January 1990, a variety of mechanical valves (St. Jude Medical, CarboMedics, ATS Medical) have been implanted routinely at the authors' institution. The study aim was to analyze, retrospectively, the 20-year clinical results of those mechanical valves, and to challenge the anticoagulation policy employed over the years.

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Objectives: The objective of this study was to investigate the patient characteristics and outcomes in 1406 patients undergoing intra-aortic balloon pump (IABP) counterpulsation.

Methods: Between 1998 and 2008, 1406 consecutive patients were recorded in a prospective database. Based on the main clinical indication for IABP use, we defined 3 groups: group A, 630 cases of coronary ischaemia or infarction without serious left ventricular (LV) dysfunction; group B, 466 patients with left ventricular failure or cardiogenic shock; group C, 310 patients where IABP was used for miscellaneous procedures such as weaning from cardiopulmonary bypass or during high-risk angioplasty or surgery.

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Objective: Currently used decellularization procedures have negative effects on extracellular matrix (ECM) integrity. The objective of this study is to evaluate four decellularization methods and their effect on the collagen ultrastructure, mechanical behavior and antigenicity of porcine aortic valves.

Methods: Aortic valves were placed in a trypsin, osmotic, trypsin-osmotic or detergent-osmotic solution.

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Growth factors that regulate proliferation, migration, and invasion of ovine mesenchymal stem cells (oMSCs) are not well defined. In this study, we have evaluated five growth factors for their ability to initiate and support in vitro proliferation, migration, and invasion of oMSCs. oMSCs were exposed to different doses and combinations of the growth factors: basic fibroblast growth factor (bFGF), transforming growth factor-β (TGF-β), epidermal growth factor (EGF), insulin growth factor-I (IGF-I), connective tissue growth factor, and platelet-derived growth factor-AB (PDGF-AB).

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Background: Diabetes mellitus increases adverse outcomes after coronary revascularization; however, the impact of metabolic syndrome is unclear. We examined the impact of diabetes and metabolic syndrome on coronary artery bypass graft surgery (CABG) and stenting outcomes to determine the optimal revascularization option for the treatment of complex coronary artery disease.

Methods: Patients (n = 1,800) with left main or three-vessel disease or both were randomly allocated to treatment with a TAXUS Express(2) paclitaxel-eluting stent (PES) or CABG, and were included in predefined nondiabetic (n = 1,348) or diabetic subgroups (n = 452); 258 patients with diabetes also had metabolic syndrome.

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