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Featured researches published by Willem Daenen.


Transplantation | 1996

Prevention of bone loss in cardiac transplant recipients. A comparison of biphosphonates and vitamin D

Van Cleemput J; Willem Daenen; Geusens P; Dequeker P; Van De Werf F; Vanhaecke J

Bone mineral density is already abnormally reduced at the moment of cardiac transplantation and bone loss occurs at an impressive rate in the first postoperative year. The aim of the study was to compare two prophylactic medical regimens as to their efficacy in mitigating bone loss after transplantation. Forty-eight consecutive recipients were randomized to receive either alternating calcium carbonate and disodium etidronate (group A) or a daily supplement of calcium carbonate and alphacalcidol (group B). Bone mineral density measurements were performed immediately before hospital discharge and 6, 12, and 24 months after surgery using dual energy X-ray absorptiometry. Clinical events were recorded and roentgenograms of the spine were performed postoperatively and 1 and 2 years later. In both treatment groups bone loss remained significant at the level of the lumbar spine in the first postoperative year (P<0.005) and at the level of the femoral neck in the first (P<0.005) and the second (P<0.06) year after transplantation. Six months after transplantation, however, patients receiving alphacalcidol had a significant reduction in bone loss at the level of the lumbar spine (P=0.047) and at the level of the femoral neck (P=0.043). At the level of the femoral neck this decrease in bone loss was even more pronounced in the second postoperative year (P<0.001). In the group of patients treated with disodium etidronate, 4 recipients needed additional hospitalizations for treatment of symptomatic fractures at the level of the lumbar spine or the femoral neck. No such events happened in recipients receiving vitamin D supplements. Prophylactic administration of calcium carbonate and alphacalcidol after cardiac transplantation reduces bone loss and seems to decrease osteoporotic complications.


The Annals of Thoracic Surgery | 2001

Fifteen-year experience with the mitral Carpentier-Edwards PERIMOUNT pericardial bioprosthesis

Michel Marchand; Michel Aupart; Robert Norton; Ira Goldsmith; L. Conrad Pelletier; Michel Pellerin; Thomas W. Dubiel; Willem Daenen; Paul Herijgers; Filip Casselman; Michael P. Holden; Tirone E. David

BACKGROUND This multicenter study concerning the mitral PERIMOUNT valve previously reported clinical results at 12 years; this report updates the performance to 15 years postoperatively. METHODS The 435 patients (mean age 60.7+/-11.6 years; 41.1% male) underwent implantation with the PERIMOUNT valve between 1984 and 1989 at seven institutions. Follow-up was complete for 96.1% of the cohort. The mean follow-up was 8.1+/-4.4 years (range 0 to 15.4 years) for a total of 3492 patient-years. RESULTS There were 34 (7.8%) operative deaths, one (0.2%) valve related. The late mortality rate was 5.3%/patient-year (2.2%/patient-year valve related). At 14 years, the overall actuarial survival rate was 37.1%+/-3.3% (63.1%+/-4.4% valve related). Actuarial freedom from complications at 14 years was as follows: thromboembolism, 83.8%+/-3.2% (1.1%/patient-year); hemorrhage, 86.6%+/-3.2% (1.1%/patient-year); and explant due to structural valve deterioration (SVD), 68.8%+/-4.7%. Actual freedom from explant due to SVD was 83.4%+/-2.3%. Rates of structural failure decreased with increasing age at implant. CONCLUSIONS The Carpentier-Edwards PERIMOUNT Pericardial Bioprosthesis is a reliable choice for a tissue valve in the mitral position, especially in patients more than 60 years of age.


Journal of the American College of Cardiology | 1994

ALCAPA syndrome : an example of chronic myocardial hypoperfusion ?

Bharati Shivalkar; Marcel Borgers; Willem Daenen; Marc Gewillig; Willem Flameng

OBJECTIVES The purpose of this study was to evaluate functional variables and morphologic correlates of chronically hypoperfused myocardium before and after revascularization. BACKGROUND Neonates with congenital anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA syndrome) develop some myocardial necrosis shortly after birth. The survivors of this event are left with a localized infarction and an almost entirely collateral circulation-dependent perfusion of the left ventricle that results in poor global left ventricular function. Survival beyond infancy is uncommon because of severe left heart failure. Revascularization, however, brings about functional recovery with good clinical outcome. The ALCAPA syndrome is thus characterized by chronic collateral circulation-dependent low perfusion, low contraction matching and potential revivability. METHODS Five patients with ALCAPA syndrome are presented, with preoperative and postoperative clinical findings and histologic data obtained from intraoperative transmural biopsy specimens. RESULTS The angiographically assessed preoperative ejection fraction was 33 +/- 19% (mean +/- SD). Postoperative echocardiographic follow-up revealed normal left ventricular function in all patients. Histologic study of the biopsy specimens taken from the region perfused by the anomalous artery showed a variable degree of fibrosis (51 +/- 32%). The ultrastructure of the remaining myocytes revealed viable characteristics, but a substantial percent (46 +/- 26%) showed a markedly reduced fraction of contractile material. CONCLUSIONS These ultrastructural studies suggest delayed subcellular adaptive responses in the chronically hypoperfused myocardium of patients with ALCAPA syndrome.


The Annals of Thoracic Surgery | 1996

Determinants of early and late results of combined valve operations and coronary artery bypass grafting.

Willem Flameng; Paul Herijgers; J Szecsi; Paul Sergeant; Willem Daenen; Ilse Scheys

BACKGROUND Factors determining the outcome of operative correction of valvular abnormalities combined with coronary artery bypass grafting are still incompletely defined. METHODS Determinants of early and late (more than 90 days) deaths and event-free survival were studied for combined valve operations and coronary artery bypass grafting in 741 patients using multivariate analysis. RESULTS Ninety-day survival probability was 89% (95% confidence interval, 87% to 92%). Preoperative risk factors for early death were age, female sex, renal failure, New York Heart Association class IV or V, and mitral insufficiency. The operative risk factor was the duration of aortic cross-clamping. Five- and 10-year survival probabilities were 74% (95% confidence interval, 71% to 78%) and 43% (95% confidence interval, 36% to 50%), respectively. Preoperative risk factors for late death were age, preoperative renal failure, New York Heart Association class IV or V, vessel disease, and nonsinus rhythm. Five- and 10-year event-free survival probabilities were 57% (95% confidence interval, 53% to 61%) and 23% (95% confidence interval, 17% to 28%), respectively. Preoperative risk factors for non-event-free survival were age, female sex, reduced left ventricular function, mitral regurgitation, and pacemaker rhythm. CONCLUSION The demographic factors of age and female sex; the comorbid condition of renal failure; the cardiac conditions of advanced New York Heart Association class, left ventricular function, mitral regurgitation, vessel disease, and cardiac rhythm; and the operative condition of ischemia time are the most important predictors of clinical outcome after combined valve operations and coronary artery bypass grafting.


The Journal of Thoracic and Cardiovascular Surgery | 1999

Structural valve deterioration in mitral replacement surgery: comparison of Carpentier-Edwards supra-annular porcine and perimount pericardial bioprostheses.

W.R. Eric Jamieson; Michel Marchand; Conrad L. Pelletier; Robert Norton; Michel Pellerin; Thomas W. Dubiel; Michel Aupart; Willem Daenen; Michael P. Holden; Tirone E. David; Eke A. Ryba; William N. Anderson

BACKGROUND Bioprostheses preserved with glutaraldehyde, both porcine and pericardial, have been available as second-generation prostheses for valve replacement surgery. The performance with regard to structural valve deterioration with the Carpentier-Edwards supra-annular (CE-SAV) porcine bioprosthesis and the Carpentier-Edwards Perimount (CE-P) pericardial bioprosthesis (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) was evaluated to determine whether there was a difference in mitral valve replacement. METHODS The CE-SAV bioprosthesis was implanted in 1266 overall mitral valve replacements (isolated mitral, 1066; mitral in multiple, 200) and the CE-P bioprosthesis in 429 overall mitral valve replacements (isolated mitral, 328; mitral in multiple, 101). The mean age of the CE-SAV population was 64.2 +/- 12.2 years and that of the CE-P population, 60.7 +/- 11.7 years (P =.0001). For the study, structural valve deterioration was diagnosed at reoperation for explantation. RESULTS The freedom from structural valve deterioration was evaluated to 10 years, and the freedom rates reported are at 10 years. For the overall mitral valve replacement groups, the actuarial freedom from deterioration was significant (P =.0001): CE-P > CE-SAV for 40 years or younger, 80% versus 60%; 41 to 50 years, 91% versus 61%; 51 to 60 years, 84% versus 69%; 61 to 70 years, 95% versus 75%. The older than 70-year group was 100% versus 92% (no significant difference). The actual freedom from structural valve deterioration also demonstrated the same pattern at 10 years: 40 years or younger, CE-P 82% versus CE-SAV 68%; 41 to 50 years, 92% versus 70%; 51 to 60 years, 90% versus 80%; 61 to 70 years, 97% versus 88%; and older than 70 years, 100% versus 97%. The independent risk factors of structural valve deterioration for the overall mitral valve replacement group were age and age groups and prosthesis type (CE-SAV > CE-P). The prosthesis type either in isolated replacement or in multiple replacement was not predictive of structural valve deterioration. The pathology of structural valve deterioration was different: 70% of CE-P failures were due to calcification and 57% of CE-SAV failures were due to combined calcification and leaflet tear. CONCLUSION The actuarial and actual freedom from structural valve deterioration, diagnosed at reoperation, is greater at 10 years for CE-P than for CE-SAV bioprostheses. The mode of failure is different, and the cause remains obscure. Long-term evaluation is recommended, because the different modes of failure may alter the clinical performance by 15 and 20 years.


The Annals of Thoracic Surgery | 1998

Fetal cardiac tamponade due to an intrapericardial teratoma

Tim Tollens; Filip Casselman; Hugo Devlieger; Marc Gewillig; Kamiel Vandenberghe; Toni Lerut; Willem Daenen

A case of an intrapericardial tumor diagnosed in utero at 26 weeks of gestation is presented. The prenatal echocardiographic follow-up of an incipient hydrops fetalis determined the management and the emergency surgical treatment. Histologically, the tumor appeared to be a benign teratoma, grade I. In the postoperative period an unexpected mediastinal tumor was found and removed later. This tumor also appeared to be a benign teratoma, grade 0. Both teratomas were independent and therefore primary.


European Journal of Cardio-Thoracic Surgery | 2003

Optimal Structure of a Congenital Heart Surgery Department in Europe: by EACTS Congenital Heart Disease Committee1

Willem Daenen; Francois Lacour-Gayet; T. Aberg; Juan V. Comas; S.H. Daebritz; R. Di Donato; J.R.L. Hamilton; Harald Lindberg; Bohdan Maruszewski; J. Monro

2003;24:343-351 Eur J Cardiothorac Surg Hamilton, H. Lindberg, B. Maruszewski and J. Monro W. Daenen, F. Lacour-Gayet, T. Aberg, J.V. Comas, S.H. Daebritz, R. Di Donato, J.R.L. 1 Congenital Heart Disease Committee Optimal Structure of a Congenital Heart Surgery Department in Europe: by EACTS This information is current as of April 16, 2008 http://ejcts.ctsnetjournals.org/cgi/content/full/24/3/343 the World Wide Web at: The online version of this article, along with updated information and services, is located on


European Journal of Pediatrics | 1995

Serial cardiorespiratory exercise testing in patients with congenital heart disease

Tony Reybrouck; Ralph Rogers; M Weymans; M Dumoulin; M Vanhove; Willem Daenen; L G Van der Hauwaert; Marc Gewillig

Aerobic capacity of patients with different forms of congenital heart disease was serially evaluated in 79 patients and the evolution was correlated with the lesion and the level of daily activity. The patients were divided into six groups: patients with a small ventricular septal defect (VSD) with mini shunt (n=14), mild pulmonary valve stenosis with gradient <40 mm Hg (PS) (n=12), mild to moderate aortic valve stenosis (gradient 36±17 mm Hg) (AS) (n=12), patients 4.7±2.1 years after repair of tetralogy of Fallot (PO-TF) (n=16), patients 2.2±2.9 years after closure of a high flow/high gradient VSD (PO-VSD) (n=13), and patients 2.6±1.7 years after Fontan repair (Fontan-PO) (n=12). Aerobic capacity was assessed by determination of the ventilatory anaerobic threshold (VAT). VAT reflects the highest aerobic exercise level prior to a disproportionate increase of CO2 and ventilation relative to O2 uptake; it is independent of patient motivation. Data are expressed as percentage of normal O2 uptake at VAT, determined in 234 age/gender matched controls. The habitual level of physical activity was assessed by a standardised questionnaire. Aerobic capacity in all subgroups of patients, even with very mild defects, was at or below the lower limit of normal. Children left unrestricted from physical exercise (VSD, PS, PO-VSD) had no change over the study period. However, aerobic capacity of patients with medically imposed physical restrictions (AS) and significant residual haemodynamic lesions (PO-TF, Fontan) decreased with age. In patients with AS, PO-TF and Fontan-PO the habitual level of physical activity was significantly decreased compared to controls.ConclusionCardiovascular exercise performance in children with medically imposed restriction of intensive physical exercise (AS) or residual haemodynamic lesions (TF and Fontan-PO) declines progressively during medium-term follow up. In the other patient groups (VSD, PS, VSD-PO), exercise performance remains stable.


Transplantation | 1994

Safety and efficacy of low dose simvastatin in cardiac transplant recipients treated with cyclosporine

Johan Vanhaecke; Jo Van Cleemput; Johan Van Lierde; Willem Daenen; Hilaire De Geest

Hyperlipidemia is common in heart transplant patients. Lipid-lowering therapy poses special problems, yet may be important because accelerated graft atherosclerosis is the major factor limiting long-term survival. Simvastatin 5 mg/day was started > 6 months after surgery in 26 consecutive cardiac transplant recipients with a total serum cholesterol level of > 250 mg/dl. The dose of simvastatin was increased in 5-mg increments until total serum cholesterol fell below 220 mg/dl or until side effects developed or up to a maximal dose of 20 mg/day. The final average daily dose was 10 mg. Changes in serum lipid levels after 6 months of therapy were compared with data from a matched and concurrent control group of heart transplant patients not taking simvastatin. Immunosuppression for both groups consisted of CsA, AZA, and corticosteroids. In the simvastatin-treated group, the serum level of total cholesterol decreased by 27% from 315pm53 to 230pm38 mg/dl (P<0.0001), low density lipoprotein cholesterol decreased by 40% from 205pm30 to 123pm32 mg/dl (P<0.0001), and triglycerides decreased by 21% from 177pm89 to 140pm49 mg/dl (P<0.01). There was no significant change in high density lipoprotein cholesterol level. Body weight and CsA blood levels remained stable. Steroid intake decreased during the study period to a similar extent in both the treated and the control groups. In the control group, no significant changes in serum lipid levels were observed. Two patients experienced a mild form of myotoxicity. In one other patient simvastatin treatment was stopped after an acute pancreatitis of uncertain etiology developed. Low dose simvastatin effectively lowers total serum cholesterol, low density lipoprotein cholesterol, and triglycerides in heart transplant patients. With due precautions, the safety profile of the drug in this patient population seems reasonable.


European Journal of Cardio-Thoracic Surgery | 2010

Surgery for complications of trans-catheter closure of atrial septal defects: a multi-institutional study from the European Congenital Heart Surgeons Association

George E. Sarris; George Kirvassilis; Prodromos Zavaropoulos; Emre Belli; Hakan Berggren; Thierry Carrel; Juan V. Comas; Willem Daenen; Duccio Di Carlo; Tjark Ebels; José Fragata; Leslie Hamilton; Viktor Hraska; Jeffrey P. Jacobs; Stojan Lazarov; Constantine Mavroudis; Dominique Metras; Jean Rubay; Christian Schreiber; Giovanni Stellin

OBJECTIVE This study aims to analyse the collective experience of participating European Congenital Heart Surgeons Association centres in the surgical management of complications resulting from trans-catheter closure of atrial septal defects (ASDs). METHODS The records of all (n=56) patients, aged 3-70 years (median 18 years), who underwent surgery for complications of trans-catheter ASD closure in 19 participating institutions over a 10-year period (1997-2007) were retrospectively reviewed. Risk factors for surgical complications were sought. Surgical outcomes were compared with those reported for primary surgical ASD closure in the European Association of Cardio-thoracic Surgery Congenital Database. RESULTS A wide range of ASD sizes (5-34mm) and devices of various types and sizes (range 12-60mm) were involved, including 13 devices less than 20mm. Complications leading to surgery included embolisation (n=29), thrombosis/thrombo-embolism/cerebral ischaemia or stroke (n=12), significant residual shunt (n=12), aortic or atrial perforation or erosion (n=9), haemopericardium with tamponade (n=5), aortic or mitral valve injury (n=2) and endocarditis (n=1). Surgery (39 early emergent and 17 late operations) involved device removal, repair of damaged structures and ASD closure. Late operations were needed 12 days to 8 years (median 3 years) after device implantation. There were three hospital deaths (mortality 5.4%). During the same time period, mortality for all 4453 surgical ASD closures reported in the European Association of Cardio-Thoracic Surgery Congenital Database was 0.36% (p=0.001). CONCLUSIONS Trans-catheter device closure of ASDs, even in cases when small devices are used, can lead to significant complications requiring surgical intervention. Once a complication leading to surgery occurs, mortality is significantly greater than that of primary surgical ASD closure. Major complications can occur late after device placement. Therefore, lifelong follow-up of patients in whom ASDs have been closed by devices is mandatory.

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Marc Gewillig

Katholieke Universiteit Leuven

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Willem Flameng

Katholieke Universiteit Leuven

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Georges Stalpaert

Katholieke Universiteit Leuven

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Bart Meyns

Katholieke Universiteit Leuven

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R Suy

Katholieke Universiteit Leuven

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Paul Herijgers

Katholieke Universiteit Leuven

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Johan Vanhaecke

Katholieke Universiteit Leuven

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Paul Sergeant

Katholieke Universiteit Leuven

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Benedicte Eyskens

Katholieke Universiteit Leuven

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M Dumoulin

Katholieke Universiteit Leuven

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