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Dive into the research topics where Robert A.E. Dion is active.

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Featured researches published by Robert A.E. Dion.


The Journal of Thoracic and Cardiovascular Surgery | 2011

Tricuspid annuloplasty prevents right ventricular dilatation and progression of tricuspid regurgitation in patients with tricuspid annular dilatation undergoing mitral valve repair

Nico R.L. van de Veire; Jerry Braun; Victoria Delgado; Michel I.M. Versteegh; Robert A.E. Dion; Robert J.M. Klautz; Jeroen J. Bax

OBJECTIVESnWe hypothesize that concomitant tricuspid annuloplasty in patients with tricuspid annular dilatation who undergo mitral valve repair could prevent progression of tricuspid regurgitation and right ventricular remodeling.nnnMETHODSnIn 2002, 80 patients underwent mitral valve repair. Concomitant tricuspid annuloplasty was performed in 13 patients with grade 3 or 4 tricuspid regurgitation. In 2004, 102 patients underwent mitral valve repair. Concomitant tricuspid annuloplasty was performed in 21 patients with grade 3 or 4 tricuspid regurgitation and in 43 patients with an echocardiographically determined tricuspid annular diameter of 40 mm orxa0greater. Patients underwent transthoracic echocardiographic analysis preoperatively and at the 2-year follow-up.nnnRESULTSnIn the 2002 cohort right ventricular dimensions did not decrease (right ventricular long axis, 69xa0± 7 vs 70xa0± 8 mm; right ventricular short axis, 29xa0± 7 vs 30xa0± 7 mm); tricuspid regurgitation grade and gradient remained unchanged. In the 2004 cohort right ventricular reverse remodeling was observed (right ventricular long axis, 71xa0± 6 vs 69xa0± 9 mm; right ventricular short axis, 29xa0± 5 vs 27xa0± 5 mm; Pxa0<xa0.0001); tricuspid regurgitation diminished (1.6xa0± 1.0 vs 0.9xa0± 0.6, Pxa0<xa0.0001), and transtricuspid gradient decreased (28xa0± 13 vs 23xa0± 15 mm Hg, Pxa0=xa0.021). Subanalysis of the 2002 cohort showed that in 23 patients without grade 3 or 4 tricuspid regurgitation but baseline tricuspid annular dilatation, the degree of tricuspid regurgitation was worse at the 2-year follow-up. Moreover, this caused right ventricular dilatation. Subanalysis of the 2004 cohort demonstrated reverse right ventricular remodeling and decreased tricuspid regurgitation in 43 patients with preoperative tricuspid annular dilatation who underwent tricuspid annuloplasty.nnnCONCLUSIONSnConcomitant tricuspid annuloplasty during mitral valve repair should be considered in patients with tricuspid annular dilatation despite the absence of important tricuspid regurgitation at baseline because this improves echocardiographic outcome.


American Journal of Cardiology | 2010

Predictors of Mitral Regurgitation Recurrence in Patients With Heart Failure Undergoing Mitral Valve Annuloplasty

Agnieszka Ciarka; Jerry Braun; Victoria Delgado; Michel I.M. Versteegh; Eric Boersma; Robert J.M. Klautz; Robert A.E. Dion; Jeroen J. Bax; Nico R.L. van de Veire

Restrictive mitral annuloplasty is a surgical treatment option for patients with heart failure (HF) and functional mitral regurgitation (MR). However, recurrent MR has been reported at mid-term follow-up. The aim of the present study was to identify the echocardiographic predictors of recurrent MR in patients with HF undergoing mitral annuloplasty. During a mean follow-up of 2.6 +/- 1.6 years, 109 patients with HF (49% ischemic and 51% idiopathic dilated cardiomyopathy) who had undergone mitral valve repair were followed up (of 122 total patients). The severity of MR was quantified, and the following parameters were measured before intervention and at the mid-term follow-up examination: left ventricular (LV) and left atrial volumes and dimensions, LV sphericity index, mitral annular area, and mitral valve geometry parameters. At mid-term follow-up, 21 patients presented with significant MR (grade 2 to 4), and 88 patients had only MR grade 0 to 1. Both groups of patients had had a similar preoperative MR grade, mitral annular area, and LV volume and dimension. In contrast, patients with recurrent MR had had increased preoperative posterior and anterior leaflet angles, tenting height, tenting area, and LV sphericity index compared to the patients without recurrent MR. Of the different parameters of mitral and LV geometry, the distal mitral anterior leaflet angle (hazard ratio 1.48, 95% confidence interval 1.32 to 1.66, p <0.001) and posterior leaflet angle (hazard ratio 1.13, 95% confidence interval 1.07 to 1.19, p <0.001) were independent determinants of MR at mid-term follow-up. In conclusion, in patients with HF of ischemic or idiopathic etiology and functional MR, distal mitral leaflet tethering and posterior mitral leaflet tethering were associated with recurrent MR after restrictive mitral annuloplasty.


European Journal of Cardio-Thoracic Surgery | 2001

Pulmonary valve insertion late after repair of Fallot's tetralogy

Mark G. Hazekamp; M.M.J. Kurvers; P.H. Schoof; Hubert W. Vliegen; B.J.M. Mulder; Arno A.W. Roest; Jaap Ottenkamp; Robert A.E. Dion

Objectives: To analyze the results of pulmonary valve insertion late after initial repair of Fallot’s tetralogy. Pulmonary insufficiency (PI) after correction of Fallot’s tetralogy is usually well tolerated in the short term, but is associated with symptomatic right ventricular dilatation and an increased risk of ventricular arrhythmias over longer periods of time. Methods: From 1993 to July 2000, 51 patients were reoperated for PI at a mean age of 25.7 ^ 11.9 years. The mean age at initial repair was 6.4 ^ 7.2 years. Patients with a conduit inserted at initial operation, with absent pulmonary valve syndrome or with a more than moderate ventricular septal defect at reoperation were excluded from the study. A cryopreserved pulmonary (96%) or aortic (4%) homograft was implanted in the orthotopic position with the use of cardiopulmonary bypass 19.3 ^ 9.1 years (2.7‐40.3 years) after initial correction. Preoperative symptoms (New York Heart Association, NYHA class), degree of PI (echo-Doppler, MRI), right ventricular dimensions (MRI) and QRS duration were compared to findings at last follow-up. Results: Follow-up is complete and had a mean duration of 1.7 ^ 1.4 years. Hospital mortality was 2%. No serious morbidity occurred. Severe PI was present preoperatively in all patients. At last follow-up echo-Doppler studies showed PI to be absent or trivial in 96% and mild in 4% of patients. In 13 patients MRI studies were performed both pre- and postoperatively: in this group PI was reduced from a mean of 48 to 4%. After 6 months NYHA capacity class had improved significantly from 2.3 ^ 0.6 to 1.4 ^ 0.5. After 1 year end-diastolic and end-systolic right ventricular volumes were reduced significantly. Right ventricular ejection fraction and QRS duration remained unchanged. Conclusions: PI late after correction of Fallot’s tetralogy may lead to serious symptomatic right ventricle dilatation. After pulmonary homograft insertion right ventricular dimensions decrease rapidly and functional improvement is observed in almost all patients. q 2001 Elsevier Science B.V. All rights reserved.


The Annals of Thoracic Surgery | 2004

Long-term follow-up of coronary artery bypass grafting in three-vessel disease using exclusively pedicled bilateral internal thoracic and right gastroepiploic arteries

Giuseppe Tavilla; Arie Pieter Kappetein; Jerry Braun; Jiwan Gopie; Andrew Tjon Joek Tjien; Robert A.E. Dion

BACKGROUNDnConsiderable data now exist that show that coronary artery bypass grafting with bilateral internal thoracic artery (ITA) grafts produce better outcomes than the use of a single ITA graft. The benefit of a third arterial graft has been less well established. Therefore this article describes the survival and cardiac-related event-free survival in patients having bilateral ITA and gastroepiploic artery (GEA) grafting for 3-vessel disease.nnnMETHODSnFrom November 1992 to May 2002, 201 patients (mean age 53 +/- 7 years) presented with 3-vessel disease and received exclusively bilateral internal thoracic (ITAs) and right gastroepiploic (GEA) arteries as pedicled grafts for coronary artery bypass procedure. Twenty-seven (13%) patients were not elective, 10 (5%) were reoperations, 115 (57%) had one or more myocardial infarction, 21 (10%) had diabetes. In total 733 anastomoses were constructed (3.7/patient), with sequential grafting in 124 (62%) patients. The clinical follow-up was complete. The patients were followed for up to 10 years (mean 6.4 +/- 2.7 years).nnnRESULTSnTen-year actuarial survival (including in-hospital death) was 87%. The actuarial freedom from angina pectoris, after hospital discharge, was 97% and 86% at 5 and 10 years respectively. None of the patients needed a repeat surgical revascularization after leaving the hospital, whereas 9 (5%) patients underwent a percutaneous transluminal coronary angioplasty. At 5 years 86% and at 10 years 69% of the patients remained free of any cardiac-related event.nnnCONCLUSIONSnThe results of this study clearly indicate that the exclusive and extensive use of pedicled bilateral ITA and GEA in coronary bypass grafting provides excellent 10-year patient survival and functional improvement in terms of freedom from return of angina pectoris and, more impressive, freedom from any cardiac-related event. Our findings clearly corroborate the concomitant use of bilateral ITA and GEA grafts in selected patients with 3-vessel disease.


Asaio Journal | 2006

Modeling ventricular function during cardiac assist: does time-varying elastance work?

Stijn Vandenberghe; Patrick Segers; Paul Steendijk; Bart Meyns; Robert A.E. Dion; James F. Antaki; Pascal Verdonck

The time-varying elastance theory of Suga et al. is widely used to simulate left ventricular function in mathematical models and in contemporary in vitro models. We investigated the validity of this theory in the presence of a left ventricular assist device. Left ventricular pressure and volume data are presented that demonstrate the heart-device interaction for a positive-displacement pump (Novacor) and a rotary blood pump (Medos). The Novacor was implanted in a calf and used in fixed-rate mode (85 BPM), whereas the Medos was used at several flow levels (0–3 l/min) in seven healthy sheep. The Novacor data display high beat-to-beat variations in the amplitude of the elastance curve, and the normalized curves deviate strongly from the typical bovine curve. The Medos data show how the maximum elastance depends on the pump flow level. We conclude that the original time-varying elastance theory insufficiently models the complex hemodynamic behavior of a left ventricle that is mechanically assisted, and that there is need for an updated ventricular model to simulate the heart–device interaction.


Acta Physiologica | 2010

Single‐beat estimation of the left ventricular end‐systolic pressure–volume relationship in patients with heart failure

E. A. Ten Brinke; Robert J.M. Klautz; Harriette F. Verwey; E. E. van der Wall; Robert A.E. Dion; Paul Steendijk

Aim:u2002 The end‐systolic pressure–volume relationship (ESPVR) constructed from multiple pressure–volume (PV) loops acquired during load intervention is an established method to asses left ventricular (LV) contractility. We tested the accuracy of simplified single‐beat (SB) ESPVR estimation in patients with severe heart failure.


European Journal of Cardio-Thoracic Surgery | 2008

Early and late outcome of left ventricular reconstruction surgery in ischemic heart disease

Patrick Klein; Jeroen J. Bax; Leslee J. Shaw; Harm H. H. Feringa; Michel I.M. Versteegh; Robert A.E. Dion; Robert J.M. Klautz

A systematic review of the literature was performed to determine early and late mortality associated with left ventricular (LV) reconstruction surgery and to assess the influence of different surgical techniques, concomitant surgical procedures, clinical and hemodynamic parameters on mortality. The MEDLINE database (January 1980-January 2005) was searched and from the pooled data, hospital mortality and survival were calculated. Summary estimates of relative risks (RR) were calculated for the techniques that were used and for concomitant coronary artery bypass grafting (CABG) and mitral valve surgery. The risk-adjusted relationships between mortality and clinical and hemodynamic parameters were assessed by meta-regression. A total of 62 studies (12,331 patients) were identified. Weighted average early mortality was 6.9%. Cumulative 1-year, 5-year and 10-year survival were 88.5%, 71.5% and 53.9%, respectively. Endoventricular reconstruction (EVR) showed a reduced risk for both early (RR=0.79, p<0.005) and late (RR=0.67, p<0.001) mortality compared to the linear repair (early: RR=1.38, p<0.001; late: RR=1.83, p<0.001). Early and late mortality were mainly cardiac in origin, with as predominant cause heart failure in respectively 49.7% and 34.5% of the cases. Ventricular arrhythmias caused 16.6% of early deaths and 17.2% of late deaths. Concomitant CABG significantly decreased late mortality (RR=0.28, p<0.001) without increasing early mortality (RR=1.018, p=0.858). Concomitant mitral valve surgery showed both an increased risk for early (RR=1.57, p=0.001) and late mortality (RR=4.28, p<0.001). No clinical or hemodynamic parameters were found to influence mortality. It is noteworthy that only one third of patients included in the current analysis were operated for heart failure (14 studies, 4135 patients). In this group we noted an early mortality of 11.0% with a late mortality (3-year) of 15.2%. This analysis of pooled literature data showed that LV reconstruction surgery is performed with acceptable mortality and EVR may be the preferred technique with a reduced risk for early and late mortality. Concomitant CABG improved outcome, whereas the need for mitral valve surgery appeared an index of gravity. No clinical or hemodynamic parameters were found to influence mortality; specifically LV ejection fraction and LV volumes both did not predict outcome.


The Annals of Thoracic Surgery | 2010

Clinical and Functional Effects of Restrictive Mitral Annuloplasty at Midterm Follow-Up in Heart Failure Patients

Ellen A. ten Brinke; Robert J.M. Klautz; Sven A. Tulner; Harriette F. Verwey; Jeroen J. Bax; Victoria Delgado; Eduard R. Holman; Martin J. Schalij; Ernst E. van der Wall; Jerry Braun; Michel I.M. Versteegh; Robert A.E. Dion; Paul Steendijk

BACKGROUNDnRestrictive mitral annuloplasty (RMA) is increasingly applied to treat functional mitral regurgitation in heart failure patients. Previous studies indicated beneficial clinical effects with low recurrence rates. However, the underlying pathophysiology is complex and outcome in terms of left ventricular function is not well known. We investigated chronic effects of RMA on ventricular function in relation to clinical outcome.nnnMETHODSnHeart failure patients (n = 11) with severe mitral regurgitation scheduled for RMA were analyzed at baseline (presurgery) and midterm follow-up by invasive pressure-volume loops, using conductance catheters. Clinical performance was evaluated by New York Heart Association class, quality-of-life-score, and 6-minute hall-walk-test.nnnRESULTSnAll patients were alive without recurrence of mitral regurgitation at follow-up (9.4 ± 4.1 months). Clinical parameters improved significantly (all p < 0.05). Global cardiac function, assessed by cardiac output, stroke volume, and stroke work did not change after RMA. Reverse remodeling was demonstrated by decreased end-systolic and end-diastolic volumes (16% and 11%, both p < 0.001). Systolic function improved, evidenced by increased ejection fraction (0.32 ± 0.05 to 0.36 ± 0.07, p = 0.001) and leftward shift of the end-systolic pressure-volume relation (ESV(100): 116 ± 43 to 74 ± 26 mL, p < 0.001). Diastolic function, however, demonstrated impairment by increased tau (69 ± 13 to 80 ± 14 ms, p < 0.001) and stiffness constant (0.022 ± 0.022 to 0.031 ± 0.028 mL(-1), p = 0.001).nnnCONCLUSIONSnRestrictive mitral annuloplasty significantly improved clinical status without recurrence of mitral regurgitation at midterm follow-up in patients with heart failure. Hemodynamic analyses demonstrated significant reverse remodeling with unchanged global function and improved systolic function, but some signs of diastolic impairment. Overall, RMA appears an appropriate therapy for patients with dilated cardiomyopathy and functional mitral regurgitation.


European Journal of Cardio-Thoracic Surgery | 2009

Wall motion score index predicts mortality and functional result after surgical ventricular restoration for advanced ischemic heart failure

Patrick Klein; Eduard R. Holman; Michel I.M. Versteegh; Eric Boersma; Harriette F. Verwey; Jeroen J. Bax; Robert A.E. Dion; Robert J.M. Klautz

OBJECTIVEnAdvanced ischemic heart failure can be treated with surgical ventricular restoration (SVR). While numerous risk factors for mortality and recurrent heart failure have been identified, no plain predictor for identifying SVR patients with left ventricular damage beyond recovery is yet available. We tested echocardiographic wall motion score index (WMSI) as a predictor for mortality or poor functional result.nnnMETHODSnOne hundred and one patients electively operated between April 2002 and April 2007 were included for analysis. All patients had advanced ischemic heart failure (NYHA-class>or=III and LVEF<or=35%). Mean logistic EuroSCORE was 10+/-8. All patients were evaluated at 1-year follow-up. Risk factors for poor outcome, defined as mortality or poor functional result (NYHA class>or=III) at 1-year follow-up were identified by univariable logistic regression analysis. Preoperatively, a 16-segment echocardiographic WMSI was calculated and receiver operating characteristic curve analysis was used to identify cut-off values for WMSI in predicting poor outcome.nnnRESULTSnEarly mortality was 9.9%, late mortality 6.6%. NYHA class improved from 3.2+/-0.4 to 1.5+/-0.7. At 1-year follow-up, 10 patients (12%) were in NYHA class III and the remaining patients were in NYHA class I or II (75 patients, 88%). WMSI was found to be the only statistically significant predictor for poor outcome (odds ratio 139, 95% confidence interval (CI) 17-1116, p<0.0001). The optimal cut-off value for WMSI in predicting mortality or poor functional result was 2.19 with a sensitivity and specificity of 82% (95% CI 81.5-82.5% and 81.4-82.6%). The area under the curve was 0.94 (95% CI 0.90-0.99). Positive and negative predictive values were 67% and 92% respectively (95% CI 66.4-67.6% and 91.4-92.6%).nnnCONCLUSIONSnSufficient residual remote myocardium is necessary to recover from a SVR procedure and to translate the surgically induced morphological changes into a functional improvement. Preoperative WMSI is a surrogate measure of residual remote myocardial function and is a promising tool for better patient selection to improve results after SVR procedures for advanced ischemic heart failure.


The Journal of Thoracic and Cardiovascular Surgery | 2010

Long-term effects of surgical ventricular restoration with additional restrictive mitral annuloplasty and/or coronary artery bypass grafting on left ventricular function: Six-month follow-up by pressure-volume loops

Ellen A. ten Brinke; Robert J.M. Klautz; Sven A. Tulner; Harriette F. Verwey; Jeroen J. Bax; Martin J. Schalij; Ernst E. van der Wall; Michel I.M. Versteegh; Robert A.E. Dion; Paul Steendijk

OBJECTIVESnPrevious studies demonstrated beneficial short-term effects of surgical ventricular restoration on mechanical dyssynchrony and left ventricular function and improved midterm and long-term clinical parameters. However, long-term effects on systolic and diastolic left ventricular function are still largely unknown.nnnMETHODSnWe studied 9 patients with ischemic dilated cardiomyopathy who underwent surgical ventricular restoration with additional restrictive mitral annuloplasty and/or coronary artery bypass grafting. Invasive hemodynamic measurements by conductance catheter (pressure-volume loops) were obtained before and 6 months after surgery. In addition, New York Heart Association classification, quality-of-life score, and 6-minute hall-walk test were assessed.nnnRESULTSnAt 6 months follow-up, all patients were alive and clinically in improved condition: New York Heart Association class from 3.3 ± 0.5 to 1.4 ± 0.7, quality-of-life score from 46 ± 22 to 15 ± 15, and 6-minute hall-walk test from 302 ± 123 to 444 ± 78 m (all P < .01). Hemodynamic data showed improved cardiac output (4.8 ± 1.4 to 5.6 ± 1.1 L/min), stroke work (6.5 ± 1.9 to 7.1 ± 1.4 mm Hg · L; P = .05), and left ventricular ejection fraction (36% ± 10% to 46% ± 10%; P < .001). Left ventricular surgical remodeling was sustained at 6 months: end-diastolic volume decreased from 246 ± 70 to 180 ± 48 mL and end-systolic volume from 173 ± 77 to 103 ± 40 mL (both P < .001). Left ventricular dyssynchrony decreased from 29% ± 6% to 26% ± 3% (P < .001) and ineffective internal flow fraction decreased from 58% ± 30% to 42% ± 18% (P < .005). Early relaxation (Tau, minimal rate of pressure change) was unchanged, but diastolic stiffness constant increased from 0.012 ± 0.003 to 0.023 ± 0.007 mL(-1) (P < .001).nnnCONCLUSIONSnSurgical ventricular restoration with additional restrictive mitral annuloplasty and/or coronary artery bypass grafting leads to sustained left ventricular volume reduction at 6 months follow-up. We observed improved systolic function and unchanged early diastolic function but impaired passive diastolic properties. Clinical improvement, supported by decreased New York Heart Association class, improved quality-of-life score, and improved 6-minute hall-walk test may be related to improved systolic function, reduced mechanical dyssynchrony, and reduced wall stress.

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Jeroen J. Bax

Leiden University Medical Center

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Robert J.M. Klautz

Leiden University Medical Center

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Paul Steendijk

Leiden University Medical Center

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Michel I.M. Versteegh

Leiden University Medical Center

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Sven A. Tulner

Leiden University Medical Center

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Martin J. Schalij

Catholic University of Leuven

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Eduard R. Holman

Leiden University Medical Center

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