Paul Herijgers | KU Leuven (original) (raw)
Papers by Paul Herijgers
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 29, 2015
Recent studies have shown that aortic diameter alone is an insufficient parameter to identify pat... more Recent studies have shown that aortic diameter alone is an insufficient parameter to identify patients at risk for aortic dissection. The aim of this study was to determine the value of the ratio of aortic diameter to medial wall thickness as a new marker of risk. We obtained data from 181 patients with an ascending aortic aneurysm (n = 94) or an acute type A aortic dissection (n = 87), surgically treated at our institution (1996-2012). Measurements of the maximum aortic diameter and the medial wall thickness were conducted by retrospective review of preoperative imaging studies and histological specimens, respectively. Nearly 60% of the dissection patients had aortic diameters smaller than 50 mm. There was a significant negative linear correlation between medial wall thickness and aortic diameter (P = 0.01) in the dissection group only. Among patients with aortic diameters above 50 mm, dissection patients had significantly thinner aortic media (P = 0.04). Among patients with a mild...
Interactive cardiovascular and thoracic surgery, 2013
Personalized external aortic root support has completed initial evaluation and has technology app... more Personalized external aortic root support has completed initial evaluation and has technology appraisal in the UK for patients with Marfan syndrome for use as an alternative to root replacement. Its long-term success in preventing aortic dissection remains uncertain. Here, we report a study in sheep to establish whether the externally supporting mesh, as used clinically, is biologically incorporated. The strength of the resulting mesh/artery composite has been tested. The carotid artery of growing sheep (n=6) was enclosed in a mesh sleeve made of a polymer, polyethylene terephthalate. After a predefined interval of 4-6 months, a length of the artery was excised, including the sleeved and unsleeved portions, and was stress tested and examined histologically. One animal died of pneumonia 7 days after implantation. Comparing sleeved with normal segments, the overall thickness was increased and there was a fibrotic sheet in the periarterial space. The overall vessel wall architecture wa...
Journal of the mechanical behavior of biomedical materials, 2015
The existence of residual stresses in human arteries has long been shown experimentally. Research... more The existence of residual stresses in human arteries has long been shown experimentally. Researchers have also demonstrated that residual stresses have a significant effect on the distribution of physiological stresses within arterial tissues, and hence on their development, e.g., stress-modulated remodeling. Through progress in medical imaging, image analysis and finite element (FE) meshing tools it is now possible to construct in vivo patient-specific geometries and thus to study specific, clinically relevant problems in arterial mechanics via FE simulations. Classical continuum mechanics and FE methods assume that constitutive models and the corresponding simulations start from unloaded, stress-free reference configurations while the boundary-value problem of interest represents a loaded geometry and includes residual stresses. We present a pragmatic methodology to simultaneously account for both (i) the three-dimensional (3-D) residual stress distributions in the arterial tissue...
Catheterization and Cardiovascular Interventions, 2015
To assess midterm (3 years) clinical outcomes of transcatheter aortic valve implantation (TAVI) i... more To assess midterm (3 years) clinical outcomes of transcatheter aortic valve implantation (TAVI) in Belgium using the Edwards SAPIEN valve or the Medtronic CoreValve transcatheter heart valve (THV). Medium and long term follow-up data of both THVs are still relatively scarce, although of great clinical relevance for a relatively new but rapidly expanding treatment modality. Therefore, reporting mid- and long term clinical outcome data, coming from large "real world" national registries, remains contributive. Between December 2007 and March 2012, 861 "real world" patients who were not candidates for surgical aortic valve replacement as decided by the local heart teams, underwent TAVI at 23 sites. Eleven sites exclusively used SAPIEN THV (n = 460), while 12 exclusively used CoreValve THV (n = 401). Differences in clinical outcomes by valve system were assessed, according to access route and baseline EuroSCORE risk profile (<10%: low, 10-20%: intermediate and >20%: high risk). Overall cumulative survival at 3 years was 51% for SAPIEN vs. 60% for CoreValve (P = 0.021). In transfemorally treated patients, SAPIEN and CoreValve had similar survival at 3 years for each of the baseline EuroSCORE cohorts (low risk: 72% vs. 76%, P = 0.45; intermediate risk: 62% vs. 59%, P = 0.94; high risk: 48% vs. 53%, P = 0.65). Cumulative midterm 3 year survival after transfemoral TAVI in "real world" patients refused for surgery with similar baseline EuroSCORE risk profile is not different between SAPIEN or CoreValve. © 2015 Wiley Periodicals, Inc.
The Japanese Journal of Thoracic and Cardiovascular Surgery, 2002
Physics in medicine and biology, Jan 7, 2015
The aim of this study was to validate carotid artery strain assessment in-vivo using ultrasound s... more The aim of this study was to validate carotid artery strain assessment in-vivo using ultrasound speckle tracking. The left carotid artery of five sheep was exposed and sonomicrometry crystals were sutured onto the artery wall to obtain reference strain. Ultrasound imaging was performed at baseline and stress, followed by strain estimation using an in-house speckle tracking algorithm tuned for vascular applications. The correlation between estimated and reference strain was r = 0.95 (p < 0.001) and r = 0.87 (p < 0.01) for longitudinal and circumferential strain, respectively. Moreover, acceptable limits of agreement were found in Bland-Altman analysis (longitudinally: -0.15 to 0.42%, circumferentially: -0.54 to 0.50%), which demonstrates the feasibility of estimating carotid artery strain using ultrasound speckle tracking. However, further studies are needed to test the algorithm on human in-vivo data and to investigate its potential to detect subclinical cardiovascular disease...
International journal of cardiology, 2014
Although tricuspid valve (TV) surgery has become more popular, isolated TV surgery is infrequentl... more Although tricuspid valve (TV) surgery has become more popular, isolated TV surgery is infrequently performed. The aims of this study were (1) to evaluate the postoperative and long-term mortality of patients undergoing isolated TV surgery, (2) to compare the outcomes of patients undergoing their first TV surgery or TV reoperation, and (3) to assess the additive value of echocardiographic and invasive hemodynamic evaluations for predicting postoperative outcome. We followed a contemporary cohort of patients undergoing isolated TV surgery from January 1, 1995, through December 31, 2011. Preoperative demographic, echocardiographic, hemodynamic, and operative data were included. Outcome was all-cause mortality. Ninety-two patients (38% male; mean age: 56±14 years) were included. Kaplan-Meier survival analyses showed that 30-day, 3-month, 5-year, and 10-year mortality were 7.9%, 15.2%, 25.7%, and 53.7%, respectively. No difference in outcome was found between patients undergoing first TV...
The Journal of thoracic and cardiovascular surgery, 2014
Acta cardiologica, 2013
Although closure of an atrial septal defect type secundum often normalizes right heart dimensions... more Although closure of an atrial septal defect type secundum often normalizes right heart dimensions and pressures, mild tricuspid insufficiency might persist. This study aimed at (1) identification of determinants explaining the persistence of tricuspid insufficiency after atrial septal defect closure, and (2) evaluation of functional capacity of patients with persistent mild tricuspid insufficiency. Twenty-five consecutive patients (age 42+17 y) were included from the outpatient clinic of congenital heart disease at the University Hospitals of Leuven. All underwent transthoracic echocardiography, semi-supine bicycle stress echocardiography and cardio-pulmonary exercise testing. Six patients (24%) had mild tricuspid insufficiency (2/4) compared to 19 patients (76%) with no or minimal tricuspid insufficiency ( 1/4) as assessed by semi-quantitative colour Doppler echocardiography. Mann-Whitney U and Fisher's exact tests were performed where applicable. Patients with persistent mild ...
The Journal of heart valve disease, 2012
Elevated pulmonary artery systolic pressure (PASP) causes functional tricuspid valve insufficienc... more Elevated pulmonary artery systolic pressure (PASP) causes functional tricuspid valve insufficiency (TI). However, the differential contribution of pressure load and right ventricular (RV) dilatation is not well established. The study aim was to evaluate both variables in relation to TI. A cross-sectional study was performed of consecutive transthoracic echocardiographic studies of patients with pre-capillary pulmonary hypertension (PH). Both, demographic data and echocardiographic RV parameters were reviewed. TI was graded semi-quantitatively with color Doppler flow imaging. Trend analyses for TI severity (TI grade 0/4, 1/4, 2/4, 3/4, or 4/4) were performed. A proportional odds logistic regression analysis was carried out to identify independent predictors of TI severity. Eighty-one patients (56 females, 25 males; mean age 60 +/- 15 years) with pre-capillary PH were evaluated. Patients with more severe TI had a significantly lower body mass index, a lower mean systemic blood pressur...
Acta cardiologica, 2012
The clinical impact of tricuspid valve regurgitation (TR) is in most cases undetermined.This stud... more The clinical impact of tricuspid valve regurgitation (TR) is in most cases undetermined.This study aimed at evaluating: (1) the prevalence of TR, (2) the degree of its relationship with several types of heart disease and (3) the association of the routine echocardiographic variables with TR in each cardiac pathology. The database of the University Hospitals of Leuven was searched for all transthoracic echocardiographic studies, performed between November 2010 and January 2011, to reach a target of at least 2000 patients. The study population was divided into predefined categories. Significant TR was defined as graded > 2/4 on colour Doppler. In total 2054 consecutive echocardiographic studies were retrieved. The prevalence of significant TR was 10.2% in the total population, ranging from 1.1% to 34.4%. TR was strongly associated with pulmonary arterial hypertension (PAH) [OR 35.8 (11.7-110.3; P < 0.001)], valvular heart disease [OR 6.7 (2.3-19.2; P < 0.001)], heart transpla...
European heart journal cardiovascular Imaging, 2013
This study was designed in order to compare the strain and strain rate deformation parameters ass... more This study was designed in order to compare the strain and strain rate deformation parameters assessed by speckle tracking imaging (STI) with those of tissue Doppler imaging (TDI) and conductance catheter measurements in chronic murine models of left ventricular (LV) dysfunction. Twenty-four male C57BL/6J mice were assigned to wild-type (n = 8), myocardial infarction (n = 8) and transaortic constriction (n = 8) groups. Echocardiographic and conductance measurements were simultaneously performed at rest and during dobutamine infusion (5 µg/kg/min) in all animals 10 weeks post-surgery. The LV circumferential strain (Scirc) and the strain rate (SRcirc) were derived from grey scale and tissue Doppler data at frame rates of 224 and 375 Hz, respectively. Scirc and SRcirc by TDI/STI correlated well with the preload recruitable stroke work (PRSW) (r = -0.64 and -0.71 for TDI; r = -0.46 and -0.50 for STI, P < 0.05). Both modalities showed a good agreement with respect to Scirc and SRcirc ...
Cardiovascular diabetology, 2012
The number of patients with diabetes or the metabolic syndrome reaches epidemic proportions. On t... more The number of patients with diabetes or the metabolic syndrome reaches epidemic proportions. On top of their diabetic cardiomyopathy, these patients experience frequent and severe cardiac ischemia-reperfusion (IR) insults, which further aggravate their degree of heart failure. Food restriction and angiotensin-converting enzyme inhibition (ACE-I) are standard therapies in these patients but the effects on cardiac IR injury have never been investigated. In this study, we tested the hypothesis that 1° food restriction and 2° ACE-I reduce infarct size and preserve cardiac contractility after IR injury in mouse models of diabetes and the metabolic syndrome. C57Bl6/J wild type (WT) mice, leptin deficient ob/ob (model for type II diabetes) and double knock-out (LDLR-/-;ob/ob, further called DKO) mice with combined leptin and LDL-receptor deficiency (model for metabolic syndrome) were used. The effects of 12 weeks food restriction or ACE-I on infarct size and load-independent left ventricul...
The Journal of heart valve disease, 2010
Triple valve surgery remains a challenge, although with an improved survival rate compared to his... more Triple valve surgery remains a challenge, although with an improved survival rate compared to historical data. Aws assessment was made as to whether the type of valve surgery, underlying valve lesion and pathology were independent predictors of outcome. The patient characteristics were also described according to the type of surgery performed. A total of 166 consecutive patients underwent triple valve surgery and were followed up between October 1972 and June 2006. The clinical and operative variables were obtained retrospectively by physicians. The median follow up was 6.11 years (interquartile range 2.13-10.43). The overall 30-day mortality was 10%, five-year survival 70%, and 10-year survival 60%. In patients with three mechanical valves, survival at five years was 90%, and 85% at 10 years, compared to 40% at five years and 30% at 10 years in patients with three bioprostheses. Among all patients with a mechanical valve in the aortic and mitral positions, those with a tricuspid bi...
Journal of the Mechanical Behavior of Biomedical Materials, 2015
Verhandelingen - Koninklijke Academie voor Geneeskunde van België, 2008
Preconditioning is the most powerful endogenous mechanism, to protect the heart against ischemic ... more Preconditioning is the most powerful endogenous mechanism, to protect the heart against ischemic damage. Conflicting data are published whether preconditioning can be induced in case of diabetes and the metabolic syndrome, which are clinically very relevant conditions. If preconditioning could be induced consistently and chronically in this population, an important reduction of surgical morbidity and mortality could be reached. In this project we induced hypoxic preconditioning in mice and used cardiac pressure-conductance catheterisation and infarct size as outcome parameters. In the first part, we found that hypoxic preconditioning was capable to reduce infarct size with 40% and preserve the load-independent parameters with 33% after coronary occlusion. A DKO (double knock-out: ob/ob; LDLR-/-) model for the metabolic syndrome developed a larger infarct size and had a reduced contractility. No preconditioning could be induced in this model. To detect the determing factor of the res...
The Journal of heart valve disease, 2008
The long-term benefits of mitral regurgitation (MR) surgery in ischemic cardiomyopathy (ICM) are ... more The long-term benefits of mitral regurgitation (MR) surgery in ischemic cardiomyopathy (ICM) are controversial. Herein are reported the results and trends of this surgical approach over the past 24-year period. Patients were identified in refractory heart failure due to ICM with NYHA functional class III/IV symptoms, left ventricular ejection fraction < or =35% and MR who underwent mitral surgery between 1979 and 2002. The early and late outcomes were analyzed and compared for the different surgical eras classified as early (1979 to 1986), middle (1987 to 1994), and late (1995 to 2002). Mitral repair (70%) and replacement (30%) were performed with coronary artery bypass grafting (CABG) (85%) and tricuspid valve repair (7%) in 179 patients (mean age 68 +/- 9 years). The overall one- and five-year survival rates were 84% and 51%, respectively, and the corresponding freedom from recurrent MR after repair 86% and 55%. An increasing number of patients underwent surgery from the early ...
Physiological research / Academia Scientiarum Bohemoslovaca, 2008
Reactive oxygen species (ROS) have been implicated in the mechanism of postischemic contractile d... more Reactive oxygen species (ROS) have been implicated in the mechanism of postischemic contractile dysfunction, known as myocardial stunning. In this study, we examined protective effects of antioxidant enzymes, superoxide dismutase (SOD) and catalase, against ischemia/reperfusion-induced cardiac dysfunction and inhibition of Na+,K+-ATPase activity. Isolated Langendorff-perfused rabbit hearts were subjected to 15 min of global normothermic ischemia followed by 10 min reperfusion. The hearts treated with SOD plus catalase did not show significant recovery of left ventricular (LV) end-diastolic pressure compared with untreated ischemic reperfused hearts. Treatment with antioxidants had no protective effects on developed LV pressure or its maximal positive and negative first derivatives (+/-LVdP/dt). Myocardial stunning was accompanied by significant loss in sarcolemmal Na+,K+-ATPase activity and thiol group content. Inhibition of enzyme activity and oxidation of SH groups were not preven...
Seminars in thoracic and cardiovascular surgery, 2001
Valve dysfunction in right side implanted bioprostheses can be caused by fibrous sheathing and cu... more Valve dysfunction in right side implanted bioprostheses can be caused by fibrous sheathing and cusp retraction. A scoring system was employed to grade the macroscopic appearance of the cusp retraction. Stentless porcine aortic valves exhibit less cusp retraction when implanted in right-sided position than stented porcine aortic valves.
Seminars in thoracic and cardiovascular surgery, 1999
Allograft valved conduits are used routinely for reconstruction of the right ventricular outflow ... more Allograft valved conduits are used routinely for reconstruction of the right ventricular outflow tract in children with congenital heart disease; however, allografts are scarce. The purpose of this study was to evaluate two stentless aortic valves that might be suitable alternatives for right ventricular outflow tract reconstruction. Twelve juvenile sheep underwent implantation of stentless aortic heterografts as an interposition in the pulmonary artery: six porcine aortic valves (Freestyle) and six fully pericardial valves (Pericarbon stentless). In each series, three valves were explanted after 3 months, the other three after 6 months. Valves were analyzed by gross inspection, radiography, and light microscopy. The porcine aortic stentless valve (Freestyle) showed extensive calcification of its aortic wall portion, with perfectly functioning, pliable cusps without calcification or fibrous overgrowth up to 6 months. The pericardial valves (Pericarbon stentless) showed extensive fib...
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, Jan 29, 2015
Recent studies have shown that aortic diameter alone is an insufficient parameter to identify pat... more Recent studies have shown that aortic diameter alone is an insufficient parameter to identify patients at risk for aortic dissection. The aim of this study was to determine the value of the ratio of aortic diameter to medial wall thickness as a new marker of risk. We obtained data from 181 patients with an ascending aortic aneurysm (n = 94) or an acute type A aortic dissection (n = 87), surgically treated at our institution (1996-2012). Measurements of the maximum aortic diameter and the medial wall thickness were conducted by retrospective review of preoperative imaging studies and histological specimens, respectively. Nearly 60% of the dissection patients had aortic diameters smaller than 50 mm. There was a significant negative linear correlation between medial wall thickness and aortic diameter (P = 0.01) in the dissection group only. Among patients with aortic diameters above 50 mm, dissection patients had significantly thinner aortic media (P = 0.04). Among patients with a mild...
Interactive cardiovascular and thoracic surgery, 2013
Personalized external aortic root support has completed initial evaluation and has technology app... more Personalized external aortic root support has completed initial evaluation and has technology appraisal in the UK for patients with Marfan syndrome for use as an alternative to root replacement. Its long-term success in preventing aortic dissection remains uncertain. Here, we report a study in sheep to establish whether the externally supporting mesh, as used clinically, is biologically incorporated. The strength of the resulting mesh/artery composite has been tested. The carotid artery of growing sheep (n=6) was enclosed in a mesh sleeve made of a polymer, polyethylene terephthalate. After a predefined interval of 4-6 months, a length of the artery was excised, including the sleeved and unsleeved portions, and was stress tested and examined histologically. One animal died of pneumonia 7 days after implantation. Comparing sleeved with normal segments, the overall thickness was increased and there was a fibrotic sheet in the periarterial space. The overall vessel wall architecture wa...
Journal of the mechanical behavior of biomedical materials, 2015
The existence of residual stresses in human arteries has long been shown experimentally. Research... more The existence of residual stresses in human arteries has long been shown experimentally. Researchers have also demonstrated that residual stresses have a significant effect on the distribution of physiological stresses within arterial tissues, and hence on their development, e.g., stress-modulated remodeling. Through progress in medical imaging, image analysis and finite element (FE) meshing tools it is now possible to construct in vivo patient-specific geometries and thus to study specific, clinically relevant problems in arterial mechanics via FE simulations. Classical continuum mechanics and FE methods assume that constitutive models and the corresponding simulations start from unloaded, stress-free reference configurations while the boundary-value problem of interest represents a loaded geometry and includes residual stresses. We present a pragmatic methodology to simultaneously account for both (i) the three-dimensional (3-D) residual stress distributions in the arterial tissue...
Catheterization and Cardiovascular Interventions, 2015
To assess midterm (3 years) clinical outcomes of transcatheter aortic valve implantation (TAVI) i... more To assess midterm (3 years) clinical outcomes of transcatheter aortic valve implantation (TAVI) in Belgium using the Edwards SAPIEN valve or the Medtronic CoreValve transcatheter heart valve (THV). Medium and long term follow-up data of both THVs are still relatively scarce, although of great clinical relevance for a relatively new but rapidly expanding treatment modality. Therefore, reporting mid- and long term clinical outcome data, coming from large &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;real world&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; national registries, remains contributive. Between December 2007 and March 2012, 861 &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;real world&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; patients who were not candidates for surgical aortic valve replacement as decided by the local heart teams, underwent TAVI at 23 sites. Eleven sites exclusively used SAPIEN THV (n = 460), while 12 exclusively used CoreValve THV (n = 401). Differences in clinical outcomes by valve system were assessed, according to access route and baseline EuroSCORE risk profile (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;10%: low, 10-20%: intermediate and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;20%: high risk). Overall cumulative survival at 3 years was 51% for SAPIEN vs. 60% for CoreValve (P = 0.021). In transfemorally treated patients, SAPIEN and CoreValve had similar survival at 3 years for each of the baseline EuroSCORE cohorts (low risk: 72% vs. 76%, P = 0.45; intermediate risk: 62% vs. 59%, P = 0.94; high risk: 48% vs. 53%, P = 0.65). Cumulative midterm 3 year survival after transfemoral TAVI in &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;real world&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; patients refused for surgery with similar baseline EuroSCORE risk profile is not different between SAPIEN or CoreValve. © 2015 Wiley Periodicals, Inc.
The Japanese Journal of Thoracic and Cardiovascular Surgery, 2002
Physics in medicine and biology, Jan 7, 2015
The aim of this study was to validate carotid artery strain assessment in-vivo using ultrasound s... more The aim of this study was to validate carotid artery strain assessment in-vivo using ultrasound speckle tracking. The left carotid artery of five sheep was exposed and sonomicrometry crystals were sutured onto the artery wall to obtain reference strain. Ultrasound imaging was performed at baseline and stress, followed by strain estimation using an in-house speckle tracking algorithm tuned for vascular applications. The correlation between estimated and reference strain was r = 0.95 (p < 0.001) and r = 0.87 (p < 0.01) for longitudinal and circumferential strain, respectively. Moreover, acceptable limits of agreement were found in Bland-Altman analysis (longitudinally: -0.15 to 0.42%, circumferentially: -0.54 to 0.50%), which demonstrates the feasibility of estimating carotid artery strain using ultrasound speckle tracking. However, further studies are needed to test the algorithm on human in-vivo data and to investigate its potential to detect subclinical cardiovascular disease...
International journal of cardiology, 2014
Although tricuspid valve (TV) surgery has become more popular, isolated TV surgery is infrequentl... more Although tricuspid valve (TV) surgery has become more popular, isolated TV surgery is infrequently performed. The aims of this study were (1) to evaluate the postoperative and long-term mortality of patients undergoing isolated TV surgery, (2) to compare the outcomes of patients undergoing their first TV surgery or TV reoperation, and (3) to assess the additive value of echocardiographic and invasive hemodynamic evaluations for predicting postoperative outcome. We followed a contemporary cohort of patients undergoing isolated TV surgery from January 1, 1995, through December 31, 2011. Preoperative demographic, echocardiographic, hemodynamic, and operative data were included. Outcome was all-cause mortality. Ninety-two patients (38% male; mean age: 56±14 years) were included. Kaplan-Meier survival analyses showed that 30-day, 3-month, 5-year, and 10-year mortality were 7.9%, 15.2%, 25.7%, and 53.7%, respectively. No difference in outcome was found between patients undergoing first TV...
The Journal of thoracic and cardiovascular surgery, 2014
Acta cardiologica, 2013
Although closure of an atrial septal defect type secundum often normalizes right heart dimensions... more Although closure of an atrial septal defect type secundum often normalizes right heart dimensions and pressures, mild tricuspid insufficiency might persist. This study aimed at (1) identification of determinants explaining the persistence of tricuspid insufficiency after atrial septal defect closure, and (2) evaluation of functional capacity of patients with persistent mild tricuspid insufficiency. Twenty-five consecutive patients (age 42+17 y) were included from the outpatient clinic of congenital heart disease at the University Hospitals of Leuven. All underwent transthoracic echocardiography, semi-supine bicycle stress echocardiography and cardio-pulmonary exercise testing. Six patients (24%) had mild tricuspid insufficiency (2/4) compared to 19 patients (76%) with no or minimal tricuspid insufficiency ( 1/4) as assessed by semi-quantitative colour Doppler echocardiography. Mann-Whitney U and Fisher's exact tests were performed where applicable. Patients with persistent mild ...
The Journal of heart valve disease, 2012
Elevated pulmonary artery systolic pressure (PASP) causes functional tricuspid valve insufficienc... more Elevated pulmonary artery systolic pressure (PASP) causes functional tricuspid valve insufficiency (TI). However, the differential contribution of pressure load and right ventricular (RV) dilatation is not well established. The study aim was to evaluate both variables in relation to TI. A cross-sectional study was performed of consecutive transthoracic echocardiographic studies of patients with pre-capillary pulmonary hypertension (PH). Both, demographic data and echocardiographic RV parameters were reviewed. TI was graded semi-quantitatively with color Doppler flow imaging. Trend analyses for TI severity (TI grade 0/4, 1/4, 2/4, 3/4, or 4/4) were performed. A proportional odds logistic regression analysis was carried out to identify independent predictors of TI severity. Eighty-one patients (56 females, 25 males; mean age 60 +/- 15 years) with pre-capillary PH were evaluated. Patients with more severe TI had a significantly lower body mass index, a lower mean systemic blood pressur...
Acta cardiologica, 2012
The clinical impact of tricuspid valve regurgitation (TR) is in most cases undetermined.This stud... more The clinical impact of tricuspid valve regurgitation (TR) is in most cases undetermined.This study aimed at evaluating: (1) the prevalence of TR, (2) the degree of its relationship with several types of heart disease and (3) the association of the routine echocardiographic variables with TR in each cardiac pathology. The database of the University Hospitals of Leuven was searched for all transthoracic echocardiographic studies, performed between November 2010 and January 2011, to reach a target of at least 2000 patients. The study population was divided into predefined categories. Significant TR was defined as graded > 2/4 on colour Doppler. In total 2054 consecutive echocardiographic studies were retrieved. The prevalence of significant TR was 10.2% in the total population, ranging from 1.1% to 34.4%. TR was strongly associated with pulmonary arterial hypertension (PAH) [OR 35.8 (11.7-110.3; P < 0.001)], valvular heart disease [OR 6.7 (2.3-19.2; P < 0.001)], heart transpla...
European heart journal cardiovascular Imaging, 2013
This study was designed in order to compare the strain and strain rate deformation parameters ass... more This study was designed in order to compare the strain and strain rate deformation parameters assessed by speckle tracking imaging (STI) with those of tissue Doppler imaging (TDI) and conductance catheter measurements in chronic murine models of left ventricular (LV) dysfunction. Twenty-four male C57BL/6J mice were assigned to wild-type (n = 8), myocardial infarction (n = 8) and transaortic constriction (n = 8) groups. Echocardiographic and conductance measurements were simultaneously performed at rest and during dobutamine infusion (5 µg/kg/min) in all animals 10 weeks post-surgery. The LV circumferential strain (Scirc) and the strain rate (SRcirc) were derived from grey scale and tissue Doppler data at frame rates of 224 and 375 Hz, respectively. Scirc and SRcirc by TDI/STI correlated well with the preload recruitable stroke work (PRSW) (r = -0.64 and -0.71 for TDI; r = -0.46 and -0.50 for STI, P < 0.05). Both modalities showed a good agreement with respect to Scirc and SRcirc ...
Cardiovascular diabetology, 2012
The number of patients with diabetes or the metabolic syndrome reaches epidemic proportions. On t... more The number of patients with diabetes or the metabolic syndrome reaches epidemic proportions. On top of their diabetic cardiomyopathy, these patients experience frequent and severe cardiac ischemia-reperfusion (IR) insults, which further aggravate their degree of heart failure. Food restriction and angiotensin-converting enzyme inhibition (ACE-I) are standard therapies in these patients but the effects on cardiac IR injury have never been investigated. In this study, we tested the hypothesis that 1° food restriction and 2° ACE-I reduce infarct size and preserve cardiac contractility after IR injury in mouse models of diabetes and the metabolic syndrome. C57Bl6/J wild type (WT) mice, leptin deficient ob/ob (model for type II diabetes) and double knock-out (LDLR-/-;ob/ob, further called DKO) mice with combined leptin and LDL-receptor deficiency (model for metabolic syndrome) were used. The effects of 12 weeks food restriction or ACE-I on infarct size and load-independent left ventricul...
The Journal of heart valve disease, 2010
Triple valve surgery remains a challenge, although with an improved survival rate compared to his... more Triple valve surgery remains a challenge, although with an improved survival rate compared to historical data. Aws assessment was made as to whether the type of valve surgery, underlying valve lesion and pathology were independent predictors of outcome. The patient characteristics were also described according to the type of surgery performed. A total of 166 consecutive patients underwent triple valve surgery and were followed up between October 1972 and June 2006. The clinical and operative variables were obtained retrospectively by physicians. The median follow up was 6.11 years (interquartile range 2.13-10.43). The overall 30-day mortality was 10%, five-year survival 70%, and 10-year survival 60%. In patients with three mechanical valves, survival at five years was 90%, and 85% at 10 years, compared to 40% at five years and 30% at 10 years in patients with three bioprostheses. Among all patients with a mechanical valve in the aortic and mitral positions, those with a tricuspid bi...
Journal of the Mechanical Behavior of Biomedical Materials, 2015
Verhandelingen - Koninklijke Academie voor Geneeskunde van België, 2008
Preconditioning is the most powerful endogenous mechanism, to protect the heart against ischemic ... more Preconditioning is the most powerful endogenous mechanism, to protect the heart against ischemic damage. Conflicting data are published whether preconditioning can be induced in case of diabetes and the metabolic syndrome, which are clinically very relevant conditions. If preconditioning could be induced consistently and chronically in this population, an important reduction of surgical morbidity and mortality could be reached. In this project we induced hypoxic preconditioning in mice and used cardiac pressure-conductance catheterisation and infarct size as outcome parameters. In the first part, we found that hypoxic preconditioning was capable to reduce infarct size with 40% and preserve the load-independent parameters with 33% after coronary occlusion. A DKO (double knock-out: ob/ob; LDLR-/-) model for the metabolic syndrome developed a larger infarct size and had a reduced contractility. No preconditioning could be induced in this model. To detect the determing factor of the res...
The Journal of heart valve disease, 2008
The long-term benefits of mitral regurgitation (MR) surgery in ischemic cardiomyopathy (ICM) are ... more The long-term benefits of mitral regurgitation (MR) surgery in ischemic cardiomyopathy (ICM) are controversial. Herein are reported the results and trends of this surgical approach over the past 24-year period. Patients were identified in refractory heart failure due to ICM with NYHA functional class III/IV symptoms, left ventricular ejection fraction < or =35% and MR who underwent mitral surgery between 1979 and 2002. The early and late outcomes were analyzed and compared for the different surgical eras classified as early (1979 to 1986), middle (1987 to 1994), and late (1995 to 2002). Mitral repair (70%) and replacement (30%) were performed with coronary artery bypass grafting (CABG) (85%) and tricuspid valve repair (7%) in 179 patients (mean age 68 +/- 9 years). The overall one- and five-year survival rates were 84% and 51%, respectively, and the corresponding freedom from recurrent MR after repair 86% and 55%. An increasing number of patients underwent surgery from the early ...
Physiological research / Academia Scientiarum Bohemoslovaca, 2008
Reactive oxygen species (ROS) have been implicated in the mechanism of postischemic contractile d... more Reactive oxygen species (ROS) have been implicated in the mechanism of postischemic contractile dysfunction, known as myocardial stunning. In this study, we examined protective effects of antioxidant enzymes, superoxide dismutase (SOD) and catalase, against ischemia/reperfusion-induced cardiac dysfunction and inhibition of Na+,K+-ATPase activity. Isolated Langendorff-perfused rabbit hearts were subjected to 15 min of global normothermic ischemia followed by 10 min reperfusion. The hearts treated with SOD plus catalase did not show significant recovery of left ventricular (LV) end-diastolic pressure compared with untreated ischemic reperfused hearts. Treatment with antioxidants had no protective effects on developed LV pressure or its maximal positive and negative first derivatives (+/-LVdP/dt). Myocardial stunning was accompanied by significant loss in sarcolemmal Na+,K+-ATPase activity and thiol group content. Inhibition of enzyme activity and oxidation of SH groups were not preven...
Seminars in thoracic and cardiovascular surgery, 2001
Valve dysfunction in right side implanted bioprostheses can be caused by fibrous sheathing and cu... more Valve dysfunction in right side implanted bioprostheses can be caused by fibrous sheathing and cusp retraction. A scoring system was employed to grade the macroscopic appearance of the cusp retraction. Stentless porcine aortic valves exhibit less cusp retraction when implanted in right-sided position than stented porcine aortic valves.
Seminars in thoracic and cardiovascular surgery, 1999
Allograft valved conduits are used routinely for reconstruction of the right ventricular outflow ... more Allograft valved conduits are used routinely for reconstruction of the right ventricular outflow tract in children with congenital heart disease; however, allografts are scarce. The purpose of this study was to evaluate two stentless aortic valves that might be suitable alternatives for right ventricular outflow tract reconstruction. Twelve juvenile sheep underwent implantation of stentless aortic heterografts as an interposition in the pulmonary artery: six porcine aortic valves (Freestyle) and six fully pericardial valves (Pericarbon stentless). In each series, three valves were explanted after 3 months, the other three after 6 months. Valves were analyzed by gross inspection, radiography, and light microscopy. The porcine aortic stentless valve (Freestyle) showed extensive calcification of its aortic wall portion, with perfectly functioning, pliable cusps without calcification or fibrous overgrowth up to 6 months. The pericardial valves (Pericarbon stentless) showed extensive fib...