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Dive into the research topics where Lex A. van Herwerden is active.

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Featured researches published by Lex A. van Herwerden.


The New England Journal of Medicine | 2001

Comparison of coronary-artery bypass surgery and stenting for the treatment of multivessel disease.

Patrick W. Serruys; Felix Unger; J. Eduardo Sousa; Adib D Jatene; Hans Bonnier; Jacques P.A.M. Schönberger; Nigel Buller; Robert Bonser; Marcel van den Brand; Lex A. van Herwerden; Marie-Angèle Morel; Ben van Hout

BACKGROUND The recent recognition that coronary-artery stenting has improved the short- and long-term outcomes of patients treated with angioplasty has made it necessary to reevaluate the relative benefits of bypass surgery and percutaneous interventions in patients with multivessel disease. METHODS A total of 1205 patients were randomly assigned to undergo stent implantation or bypass surgery when a cardiac surgeon and an interventional cardiologist agreed that the same extent of revascularization could be achieved by either technique. The primary clinical end point was freedom from major adverse cardiac and cerebrovascular events at one year. The costs of hospital resources used were also determined. RESULTS At one year, there was no significant difference between the two groups in terms of the rates of death, stroke, or myocardial infarction. Among patients who survived without a stroke or a myocardial infarction, 16.8 percent of those in the stenting group underwent a second revascularization, as compared with 3.5 percent of those in the surgery group. The rate of event-free survival at one year was 73.8 percent among the patients who received stents and 87.8 percent among those who underwent bypass surgery (P<0.001 by the log-rank test). The costs for the initial procedure were


Circulation | 2009

The Ross Procedure A Systematic Review and Meta-Analysis

Johanna J.M. Takkenberg; Loes M.A. Klieverik; Paul H. Schoof; Robert-Jan van Suylen; Lex A. van Herwerden; Pieter E. Zondervan; Jolien W. Roos-Hesselink; Marinus J.C. Eijkemans; Magdi H. Yacoub; Ad J.J.C. Bogers

4,212 less for patients assigned to stenting than for those assigned to bypass surgery, but this difference was reduced during follow-up because of the increased need for repeated revascularization; after one year, the net difference in favor of stenting was estimated to be


Journal of the American College of Cardiology | 2000

Smoking Cessation Reduces Mortality After Coronary Artery Bypass Surgery: A 20-Year Follow-up Study

Ron T. van Domburg; Karin Meeter; Dorien F.M van Berkel; Rolf F. Veldkamp; Lex A. van Herwerden; Ad J.J.C. Bogers

2,973 per patient. CONCLUSION As measured one year after the procedure, coronary stenting for multivessel disease is less expensive than bypass surgery and offers the same degree of protection against death, stroke, and myocardial infarction. However, stenting is associated with a greater need for repeated revascularization.


Journal of the American College of Cardiology | 1996

Three-dimensional echocardiography of normal and pathologic mitral valve: a comparison with two-dimensional transesophageal echocardiography.

Alessandro Salustri; Anton E. Becker; Lex A. van Herwerden; Wim B. Vletter; Folkert J. ten Cate; Jos R.T.C. Roelandt

Background— Reports on outcome after the Ross procedure are limited by small study size and show variable durability results. A systematic review of evidence on outcome after the Ross procedure may improve insight into outcome and potential determinants. Methods and Results— A systematic review of reports published from January 2000 to January 2008 on outcome after the Ross procedure was undertaken. Thirty-nine articles meeting the inclusion criteria were allocated to 3 categories: (1) consecutive series, (2) adult patient series, and (3) pediatric patient series. With the use of an inverse variance approach, pooled morbidity and mortality rates were obtained. Pooled early mortality for consecutive, adult, and pediatric patients series was 3.0% (95% confidence interval [CI], 1.8 to 4.9), 3.2% (95% CI, 1.5 to 6.6), and 4.2% (95% CI, 1.4 to 11.5). Autograft deterioration rates were 1.15% (95% CI, 1.06 to 2.06), 0.78% (95% CI, 0.43 to 1.40), and 1.38%/patient-year (95% CI, 0.68 to 2.80), respectively, and for right ventricular outflow tract conduit were 0.91% (95% CI, 0.56 to 1.47), 0.55% (95% CI, 0.26 to 1.17), and 1.60%/patient-year (95% CI, 0.84 to 3.05), respectively. For studies with mean patient age >18 years versus mean patient age ≤18 years, pooled autograft and right ventricular outflow tract deterioration rates were 1.14% (95% CI, 0.83 to 1.57) versus 1.69% (95% CI, 1.02 to 2.79) and 0.65% (95% CI, 0.41 to 1.02) versus 1.66%/patient-year (95% CI, 0.98 to 2.82), respectively. Conclusions— The Ross procedure provides satisfactory results for both children and young adults. Durability limitations become apparent by the end of the first postoperative decade, in particular in younger patients.


Journal of the American College of Cardiology | 1986

Transesophageal two-dimensional echocardiography: its role in solving clinical problems

Elma J. Gussenhoven; Meindert A. Taams; Jos R.T.C. Roelandt; Kees M. Ligtvoet; Jacky McGhie; Lex A. van Herwerden; Michael K. Cahalan

OBJECTIVES The goal of this study was to determine the influence of smoking cessation on mortality after coronary artery bypass graft surgery (CABG), which has still not been established clearly. BACKGROUND Cigarette smoking is one of the known major risk factors of coronary artery disease. METHODS One thousand and forty-one patients underwent CABG between 1971 and 1980. The preoperative and postoperative smoking habits of 985 patients (95%) could be retrieved and were analyzed in a multivariate Cox analysis. RESULTS The median follow-up was 20 years (range 13 to 26 years). Smoking status before surgery did not entail an increased risk of mortality: patients who had smoked before surgery and those who had not smoked in the year before surgery had a similar probability of survival. However, smoking cessation after surgery was an important independent predictor of a lower risk of death and coronary reintervention during the 20-year follow-up when compared with patients who continued smoking. In analyses adjusted for baseline characteristics, the persistent smokers had a greater relative risk (RR) of death from all causes (RR 1.68 [95% confidence interval 1.33 to 2.13]) and cardiac death (RR 1.75 [1.30 to 2.37]) as compared with patients who stopped smoking for at least one year after surgery. The estimated benefit of survival for the quitters increased from 3% at five years to 14% at 15 years. The quitters were less likely to undergo repeat CABG or a percutaneous coronary angioplasty procedure (RR 1.41 [1.02 to 1.94]). CONCLUSIONS Patients who continued to smoke after CABG had a greater risk of death than patients who stopped smoking. They also underwent repeat revascularization procedures more frequently. Cessation of smoking is therefore strongly recommended after CABG. Clinicians are encouraged to start or to continue smoking-cessation programs in order to help smokers to quit smoking, especially after CABG.


Journal of the American College of Cardiology | 1989

Transesophageal doppler color flow imaging in the detection of native and Björk-Shiley mitral valve regurgitation☆

Meindert A. Taams; Elma J. Gussenhoven; Michael K. Cahalan; Jos R.T.C. Roelandt; Lex A. van Herwerden; N. Bom; Nico de Jong

OBJECTIVES This study was done to ascertain whether three-dimensional echocardiography can facilitate the diagnosis of mitral valve abnormalities. BACKGROUND The value of the additional information provided by three-dimensional echocardiography compared with two-dimensional multiplane transesophageal echocardiography for evaluation of the mitral valve apparatus has not been assessed. METHODS Thirty patients with a variety of mitral valve pathologies (stenosis in 8, insufficiency in 12, prostheses in 10) and 20 subjects with a normal mitral valve were studied. Images were acquired using the rotational technique (ever 2 degrees), with electrocardiographic and respiratory gating. From the three-dimensional data sets, cut planes were selected and presented in both two-dimensional format (anyplane echocardiography) and volume-rendered dynamic display. The data were compared with the original multiplane two-dimensional images. Different features of the mitral valve apparatus were defined and graded by three observers for clarity of visualization and confidence of interpretation as 1) inadequate, 2) sufficient, or 3) excellent. RESULTS All the techniques provided good visualization of the mitral valve (mean global scores +/- SD for multiplane, anyplane and volume-rendered echocardiography were 2.22 +/- 0.34, 2.24 +/- 0.26 and 2.30 +/- 0.25, respectively). With volume-rendered echocardiography, the mitral valve apparatus was scored higher in pathologic than in normal conditions (2.38 +/- 0.24 vs. 2.16 +/- 0.21, p < 0.002). The spatial relationships between the mitral valve and other structures, leaflet mobility, commissures and orifice were scored higher by volume-rendered echocardiography. Prostheses were evaluated equally well by the three methods. Multiplane and anyplane echocardiography were superior for the evaluation of leaflet thickness, subvalvular apparatus and annulus. CONCLUSIONS Transesophageal three-dimensional echocardiography facilitates imaging of some features of the mitral valve apparatus and provides additional information for comprehensive assessment of mitral valve abnormalities.


Circulation | 2005

Percutaneous Versus Surgical Treatment for Patients With Hypertrophic Obstructive Cardiomyopathy and Enlarged Anterior Mitral Valve Leaflets

Christopher Lee; Folkert J. ten Cate; Marcel L. Geleijnse; Marcel Kofflard; Chiara Pedone; Lex A. van Herwerden; Elena Biagini; Wim B. Vletter; Patrick W. Serruys

The diagnostic value of transesophageal two-dimensional echocardiography is described in 32 patients in whom precordial echocardiography or angiography, or both, failed to establish a definitive diagnosis. All attempted transesophageal studies were completed without complication and the referral question was definitively answered. Nineteen patients were subsequently submitted to surgery. In 18 of them, the transesophageal echocardiographic diagnoses were proven correct; in 1 patient, the diagnosis was proven partially incorrect. In the 13 unoperated patients the transesophageal echocardiographic diagnoses were not independently confirmed but were assumed correct because incontrovertible images were obtained. These results indicate that transesophageal echocardiography significantly extends the diagnostic capabilities of echocardiography.


Journal of the American College of Cardiology | 1996

Initial results of combined anterior mitral leaflet extension and myectomy in patients with obstructive hypertrophic cardiomyopathy

Marcel Kofflard; Lex A. van Herwerden; David Waldstein; P. N. Ruygrok; Eric Boersma; Meindert A. Taams; Folkert J. ten Cate

Regurgitant blood flow of mitral valves was studied by transesophageal Doppler color flow echocardiographic imaging in 11 healthy volunteers (Group 1), 25 cardiac patients with a native mitral valve (Group 2), 10 patients with a normally functioning Björk-Shiley mitral prosthesis without clinical evidence of mitral regurgitation (Group 3) and 10 patients with angiographic or surgical evidence of Björk-Shiley mitral valve regurgitation (Group 4). Holosystolic regurgitant color jets were classified as type I or type II. The data were compared with results obtained with precordial techniques, i.e., continuous wave and Doppler color flow echocardiographic imaging (Groups 1 to 4) and left ventricular angiography or surgery (Groups 2 and 4). In Group 1, transesophageal Doppler color flow imaging revealed no mitral regurgitant flow in 7 of the 11 patients and a type I jet in 4 patients that was detected in only 1 patient by precordial techniques. In Group 2, angiography showed no mitral regurgitation in 20 patients and documented mitral regurgitation in 5. Transesophageal Doppler color flow imaging detected in 4 of the 20 patients a type I jet that was not visualized with precordial techniques in 2 patients. Type II jets were detected by the transesophageal technique in all five patients with proven mitral regurgitation and were also visualized with precordial echocardiography. All patients in Group 3 showed two identical type I jets that were not detected with precordial echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)


The Annals of Thoracic Surgery | 2001

Right ventricular outflow tract reconstruction with an allograft conduit

Cornelis G Gerestein; Johanna J.M. Takkenberg; Frans Oei; Adri H. Cromme-Dijkhuis; Silja Spitaels; Lex A. van Herwerden; Ewout W. Steyerberg; Ad J.J.C. Bogers

Background—The purpose of this study was to compare percutaneous transluminal septal myocardial ablation (PTSMA) and septal myectomy combined with mitral leaflet extension (MLE) in symptomatic hypertrophic obstructive cardiomyopathy patients with an enlarged anterior mitral valve leaflet (AMVL). Both PTSMA and myectomy reduce septal thickness and left ventricular outflow tract (LVOT) gradient; however, an uncorrected enlarged AMVL may predispose to residual systolic anterior motion (SAM) after successful standard myectomy or PTSMA. Myectomy with MLE previously demonstrated superior hemodynamic results compared with standard myectomy, but its value relative to PTSMA is unknown. Methods and Results—Twenty-nine patients (aged 44±12 years) underwent myectomy with MLE, and 43 patients (aged 52±17 years) underwent PTSMA. Mitral leaflet area was similar in both groups (16.7±3.4 versus 15.9±2.7 cm2, respectively). After PTSMA, 2 patients died, 4 needed a reintervention, and 4 required a permanent pacemaker for complete heart block. After surgery, only 1 patient needed a reintervention. At 1-year follow-up, LVOT gradients did not differ between surgical and PTSMA patients (17±14 versus 23±19 mm Hg, respectively). Preinterventional mitral regurgitation grade was more severe in the surgical group, but with myectomy combined with MLE, the residual grade was similar to that of PTSMA. Mean SAM grade decreased significantly more after surgery (from 2.9±0.3 to 0.5±0.7 mm Hg versus from 2.8±0.5 to 1.3±0.9 mm Hg, P<0.05). Conclusions—PTSMA in these selected patients with hypertrophic obstructive cardiomyopathy had more periprocedural complications and resulted in more reinterventions. Hemodynamic results (SAM grade and reduction in mitral regurgitation) were better in surgical patients.


The Journal of Thoracic and Cardiovascular Surgery | 1997

Does the pulmonary autograft in the aortic position in adults increase in diameter? An echocardiographic study

Raymond B. Hokken; Ad J.J.C. Bogers; Meindert A. Taams; Mieke B. Schiks-Berghourt b; Lex A. van Herwerden; Jos R.T.C. Roelandt; Egbert Bos

OBJECTIVES The purpose of this study was to describe the clinical and functional results of combined anterior mitral leaflet extension and myectomy in patients with hypertrophic obstructive cardiomyopathy. BACKGROUND Septal myectomy is the most commonly performed surgical procedure in patients with hypertrophic cardiomyopathy and left ventricular outflow tract obstruction. Because of the role of the mitral valve in creating the outflow tract gradient, mitral valve replacement or plication is performed in selected cases in combination with myectomy, often with better hemodynamic results than those of myectomy alone. Mitral valve leaflet extension, in which a glutaraldehyde-preserved autologous pericardial patch is used to enlarge the mitral valve along its horizontal axis, is a novel surgical approach in patients with hypertrophic obstructive cardiomyopathy. METHODS Eight patients with hypertrophic obstructive cardiomyopathy were treated with mitral leaflet extension and myectomy. Preoperative and postoperative data (New York Heart Association functional class, number of drugs prescribed, width of the interventricular septum, severity of mitral valve regurgitation severity of systolic anterior motion of the mitral valve and outflow tract gradient) were compared with those of 12 patients undergoing myectomy alone. RESULTS Preoperative evaluation demonstrated that mitral regurgitation and systolic anterior motion of the mitral valve were more severe in the group undergoing mitral valve extension (p < 0.001 and p < 0.05, respectively). There were no deaths associated with either surgical procedure. Two patients, both treated by myectomy alone, died during the follow-up period. Postoperatively, patients treated with mitral valve extension had less mitral regurgitation (p < 0.005), less residual systolic anterior motion (p < 0.001), greater improvement in functional class (p = 0.05) and greater reduction in the number of drugs (p < 0.005) and in septal thickness (p < 0.05). CONCLUSIONS Mitral leaflet extension in combination with myectomy is a promising new surgical approach that may provide superior results to those of myectomy alone. Further studies are needed to determine the clinical value of this procedure.

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Jos R.T.C. Roelandt

Erasmus University Rotterdam

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Ad J.J.C. Bogers

Erasmus University Rotterdam

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Egbert Bos

Erasmus University Rotterdam

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Ewout W. Steyerberg

Erasmus University Rotterdam

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Meindert A. Taams

Erasmus University Rotterdam

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Folkert J. ten Cate

Erasmus University Rotterdam

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