Olaf Schouten

Reinier de Graaf Groep, Delft, South Holland, Netherlands

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Publications (143)822.18 Total impact

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    Journal of Vascular Surgery 06/2011; 53(6). DOI:10.1016/j.jvs.2011.03.046 · 3.02 Impact Factor
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    ABSTRACT: Vascular surgery patients are at increased risk for late sudden cardiac death. Identification of patients at risk during surgery offers the opportunity for focused therapy. We monitored 483 vascular surgery patients who had no documented history of arrhythmias to identify perioperative new-onset ventricular tachyarrhythmia (VT) and myocardial ischemia using a continuous electrocardiographic (ECG) device for 72 hours. Cardiac risk factors, left ventricular ejection fraction (LVEF), medical therapy, inflammation status, and perioperative ischemia in relation to arrhythmia were noted in all patients. During follow-up, event-based outcomes analysis was used to describe survival. New-onset perioperative VT was detected in 33 patients (6.8%). A higher percentage of patients experiencing perioperative VT had reduced LVEF preoperatively than those without VT (24% vs 12%; P = .04). Additionally, fewer patients experiencing VT were receiving statins than those without (70% vs 85%; P = .02). Patients experiencing VT had a higher incidence of myocardial ischemia (30% vs 18%; P = .10). Perioperative VT was preceded by ischemia in only 60% of the cases. The overall cohort survival was 83% at 24-month follow-up (interquartile range [IQR], 1.1-1.3). Sudden cardiac death free survival among patients experiencing VT was less than in those without (79% vs 92%; P = .02). After adjusting for gender, cardiac risk factors, and type of surgery, new-onset perioperative VT was associated with sudden cardiac death (hazard ratio [HR], 2.6; 95% confidence interval [CI], 1.1-5.8). Perioperative VT is likely to be associated with late sudden cardiac death and decreased survival. Continuous perioperative ECG is an effective method to identify VT and may allow improved management of these patients.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 03/2011; 53(3):732-7; discussion 737. DOI:10.1016/j.jvs.2010.09.013 · 3.02 Impact Factor
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    T.A. Winkle · O. Schouten · S.E. Hoeks ·

    Journal of Vascular Surgery 11/2010; 52(5):1421. DOI:10.1016/j.jvs.2010.09.046 · 3.02 Impact Factor
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    O Schouten · G M J M Welten · D Poldermans ·

    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 11/2010; 40(5):616-7. DOI:10.1016/j.ejvs.2010.08.005 · 2.49 Impact Factor
  • Olaf Schouten · Hence J M Verhagen · Don Poldermans ·

    New England Journal of Medicine 10/2010; 363(15):1480-1; author reply 1481-2. · 55.87 Impact Factor
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    ABSTRACT: Major vascular surgery patients are at high risk for developing asymptomatic perioperative myocardial ischemia reflected by a postoperative troponin release without the presence of chest pain or electrocardiographic abnormalities. Long-term prognosis is severely compromised and characterized by an increased risk of long-term mortality and cardiovascular events. Current guidelines on perioperative care recommend single antiplatelet therapy with aspirin as prophylaxis for cardiovascular events. However, as perioperative surgical stress results in a prolonged hypercoagulable state, the postoperative addition of clopidogrel to aspirin within 7 days after perioperative asymptomatic cardiac ischemia could provide improved effective prevention for cardiovascular events. DECREASE-VII is a phase III, randomized, double-blind, placebo-controlled, multicenter clinical trial designed to evaluate the efficacy and safety of early postoperative dual antiplatelet therapy (aspirin and clopidogrel) for the prevention of cardiovascular events after major vascular surgery. Eligible patients undergoing a major vascular surgery (abdominal aorta or lower extremity vascular surgery) who developed perioperative asymptomatic troponin release are randomized 1:1 to clopidogrel or placebo (300-mg loading dose, followed by 75 mg daily) in addition to standard medical treatment with aspirin. The primary efficacy end point is the composite of cardiovascular death, stroke, or severe ischemia of the coronary or peripheral arterial circulation leading to an intervention. The evaluation of long-term safety includes bleeding defined by TIMI criteria. Recruitment began early 2010. The trial will continue until 750 patients are included and followed for at least 12 months. DECREASE-VII is evaluating whether early postoperative dual antiplatelet therapy for patients developing asymptomatic cardiac ischemia after vascular surgery reduces cardiovascular events with a favorable safety profile.
    American heart journal 09/2010; 160(3):387-93. DOI:10.1016/j.ahj.2010.06.038 · 4.46 Impact Factor
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    ABSTRACT: Cardiac troponin T (cTnT) assays with increased sensitivity might increase the number of positive tests. Using the area under the curve (AUC) with serial sampling of cTnT an exact quantification of the myocardial damage size can be made. We compared the prognosis of vascular surgery patients with integrated cTnT-AUC values to continuous and standard 12-lead electrocardiography (ECG) changes. 513 Patients were monitored. cTnT sampling was performed on postoperative days 1, 3, 7, 30 and/or at discharge or whenever clinically indicated. If cTnT release occurred, daily measurements of cTnT were performed, until baseline was achieved. CTnT-AUC was quantified and divided in tertiles. All-cause mortality and cardiovascular events (cardiac death and myocardial infarction) were noted during follow-up. 81/513 (16%) Patients had cTnT release. After adjustment for gender, cardiac risk factors, and site and type of surgery, those in the highest cTnT-AUC tertile were associated with a significantly worse cardiovascular outcome and long-term mortality (HR 20.2; 95% CI 10.2-40.0 and HR 4.0; 95% CI 2.0-7.8 respectively). Receiver operator analysis showed that the best cut-off value for cTnT-AUC was <0.01 days*ng m for predicting long-term cardiovascular events and all-cause mortality. In vascular surgery patients quantitative assessment of cTnT strongly predicts long-term outcome.
    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 09/2010; 40(6):739-46. DOI:10.1016/j.ejvs.2010.08.012 · 2.49 Impact Factor
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    W-J Flu · O Schouten · J-P van Kuijk · D Poldermans ·
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    ABSTRACT: Patients undergoing vascular surgery are at increased risk for developing cardiac complications. Majority of patients with perioperative myocardial damage are asymptomatic. Our objective is to review the available literature addressing the prevalence and prognostic implications of perioperative myocardial damage in vascular surgery patients. An Internet-based literature search was performed using MEDLINE to identify all published reports on perioperative myocardial damage in vascular surgery patients. Only those studies published from 2000 to 2010 evaluating myocardial damage using troponin I or T, with or without symptoms of angina pectoris were included. Thirteen studies evaluating the prevalence of perioperative myocardial ischaemia or infarction were included in the study. The incidence of perioperative myocardial ischaemia ranged from 14% to 47% and the incidence of perioperative myocardial infarction ranged from 1% to 26%. In addition, 10 studies evaluating the prognostic value of perioperative myocardial ischaemia towards postoperative mortality or the occurrence of major adverse cardiac events were included. In the retrieved studies, hazard ratios varied from 1.9 to 9.0. The high prevalence and asymptomatic nature of perioperative myocardial damage, combined with a substantial influence on postoperative mortality of vascular surgery patients, underline the importance of early detection and adequate management of perioperative myocardial damage. This article provides an extended overview regarding the prevalence and prognostic value of perioperative myocardial ischaemia and infarction in vascular surgery patients. In addition, treatment options to reduce the risk of perioperative myocardial damage are provided based on the current available literature.
    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 07/2010; 40(1):1-8. DOI:10.1016/j.ejvs.2010.03.014 · 2.49 Impact Factor
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    Journal of Vascular Surgery 06/2010; 51(6). DOI:10.1016/j.jvs.2010.02.181 · 3.02 Impact Factor
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    ABSTRACT: The prognostic value of heart failure symptoms on postoperative outcome is well acknowledged in perioperative guidelines. The prognostic value of asymptomatic left ventricular (LV) dysfunction remains unknown. This study evaluated the prognostic implications of asymptomatic LV dysfunction in vascular surgery patients assessed with routine echocardiography. Echocardiography was performed preoperatively in 1,005 consecutive vascular surgery patients. Systolic LV dysfunction was defined as LV ejection fraction less than 50%. Ratio of mitral-peak velocity during early and late filling, pulmonary vein flow, and deceleration time was used to diagnose diastolic LV dysfunction. Troponin-T measurements and electrocardiograms were performed routinely perioperatively. Multivariate regression analyses evaluated the relation between LV function and the study endpoints, 30-day cardiovascular events, and long-term cardiovascular mortality. Left ventricular dysfunction was diagnosed in 506 (50%) patients of which 80% were asymptomatic. In open vascular surgery (n = 649), both asymptomatic systolic and isolated diastolic LV dysfunctions were associated with 30-day cardiovascular events (odds ratios 2.3, 95% confidence interval [CI] 1.4-3.6 and 1.8, 95% CI 1.1-2.9, respectively) and long-term cardiovascular mortality (hazard ratios 4.6, 95% CI 2.4-8.5 and 3.0, 95% CI 1.5-6.0, respectively). In endovascular surgery (n = 356), only symptomatic heart failure was associated with 30-day cardiovascular events (odds ratio 1.8, 95% CI 1.1-2.9) and long-term cardiovascular mortality (hazard ratio 10.3, 95% CI 5.4-19.3). This study demonstrated that asymptomatic LV dysfunction is predictive for 30-day and long-term cardiovascular outcome in open vascular surgery patients. These data suggest that preoperative risk stratification should include not only solely heart failure symptoms but also routine preoperative echocardiography to risk stratify open vascular surgery patients.
    Anesthesiology 06/2010; 112(6):1316-24. DOI:10.1097/ALN.0b013e3181da89ca · 5.88 Impact Factor
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    ABSTRACT: The pathophysiology of new-onset cardiac arrhythmias is complex and may bring about severe cardiovascular complications. The relevance of perioperative arrhythmias during vascular surgery has not been investigated. The aim of this study was to assess risk factors and prognosis of new-onset arrhythmias during vascular surgery. A total of 513 vascular surgery patients, without a history of arrhythmias, were included. Cardiac risk factors, inflammatory status, and left ventricular function (LVF; N-terminal pro-B-type natriuretic peptide and echocardiography) were assessed. Continuous electrocardiography (ECG) recordings for 72 hours were used to identify ischemia and new-onset arrhythmias: atrial fibrillation, sustained ventricular tachycardia, supraventricular tachycardia, and ventricular fibrillation. Logistic regression analysis was applied to identify preoperative risk factors for arrhythmias. Cox regression analysis assessed the impact of arrhythmias on cardiovascular event-free survival during 1.7 years. New-onset arrhythmias occurred in 55 (11%) of 513 patients: atrial fibrillation, ventricular tachycardia, supraventricular tachycardia, and ventricular fibrillation occurred in 4%, 7%, 1%, and 0.2%, respectively. Continuous ECG showed myocardial ischemia and arrhythmias in 17 (3%) of 513 patients. Arrhythmia was preceded by ischemia in 10 of 55 cases. Increased age and reduced LVF were risk factors for the development of arrhythmias. Multivariate analysis showed that perioperative arrhythmias were associated with long-term cardiovascular events, irrespective of the presence of perioperative ischemia (hazard ratio 2.2, 95% CI 1.3-3.8, P = .004). New-onset perioperative arrhythmias are common after vascular surgery. The elderly and patients with reduced LVF show arrhythmias. Perioperative continuous ECG monitoring helps to identify this high-risk group at increased risk of cardiovascular events and death.
    American heart journal 06/2010; 159(6):1108-15. DOI:10.1016/j.ahj.2010.03.035 · 4.46 Impact Factor
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    Journal of Vascular Surgery 06/2010; 51(6). DOI:10.1016/j.jvs.2010.02.208 · 3.02 Impact Factor
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    ABSTRACT: Few data are available that systematically describe rates and trends of postoperative mortality for fairly large, unselected patient populations. This population-based study uses a registry of 3.7 million surgical procedures in 102 hospitals in The Netherlands during 1991-2005. Patients older than 20 yr who underwent an elective, nonday case, open surgical procedure were enrolled. Patient data included main (discharge) diagnosis, secondary diagnoses, dates of admission and discharge, death during admission, operations, age, sex, and a limited number of comorbidities classified according to the International Classification of Diseases 9th revision Clinical Modification. The main outcome measure was postoperative all-cause mortality. Univariable and multivariable logistic regression analyses were applied to evaluate the relationship between type of surgery and the main outcome. Postoperative all-cause death was observed in 67,879 patients (1.85%). In a model based on a classification into 11 main surgical categories, breast surgery was associated with lowest mortality (adjusted incidence, 0.07%), and vascular surgery was associated with highest mortality (adjusted incidence, 5.97%). In a model based on 36 surgical subcategories, the adjusted mortality ranged from 0.07% for hernia nuclei pulposus surgery to 18.5% for liver transplant. The c-index of the 36-category model was 0.88, which was significantly (P < 0.001) higher than the c-index that was associated with the simple surgical classification (low vs. high risk) in the commonly used Revised Cardiac Risk Index (c-index, 0.83). This population-based study provided a detailed and contemporary overview of postoperative mortality for the entire surgical spectrum, which may act as reference standard for surgical outcome in Western populations.
    Anesthesiology 05/2010; 112(5):1105-15. DOI:10.1097/ALN.0b013e3181d5f95c · 5.88 Impact Factor
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    ABSTRACT: Atrial fibrillation (AF) is a significant risk factor for cardiovascular (CV) mortality. This study aims to evaluate the prognostic implication of AF in patients with peripheral arterial disease (PAD). The International Reduction of Atherothrombosis for Continued Health (REACH) Registry included 23,542 outpatients in Europe with established coronary artery disease, cerebrovascular disease (CVD), PAD and/or > or =3 risk factors. Of these, 3753 patients had symptomatic PAD. CV risk factors were determined at baseline. Study end point was a combination of cardiac death, non-fatal myocardial infarction (MI) and stroke (CV events) during 2 years of follow-up. Cox regression analysis adjusted for age, gender and other risk factors (i.e., congestive heart failure, coronary artery re-vascularisation, coronary artery bypass grafting (CABG), MI, hypertension, stroke, current smoking and diabetes) was used. Of 3753 PAD patients, 392 (10%) were known to have AF. Patients with AF were older and had a higher prevalence of CVD, diabetes and hypertension. Long-term CV mortality occurred in 5.6% of patients with AF and in 1.6% of those without AF (p<0.001). Multivariable analyses showed that AF was an independent predictor of late CV events (hazard ratio (HR): 1.5; 95% confidence interval (CI): 1.09-2.0). AF is common in European patients with symptomatic PAD and is independently associated with a worse 2-year CV outcome.
    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 04/2010; 40(1):9-16. DOI:10.1016/j.ejvs.2010.03.003 · 2.49 Impact Factor
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    ABSTRACT: Local anatomy and the patient's risk profile independently affect the expansion rate of an abdominal aortic aneurysm. We describe a hybrid method that combines finite element modelling and statistical methods to predict patient-specific aneurysm expansion. The 3-D geometry of the aneurysm was imaged with computed tomography. We used finite element methods to calculate wall stress and aneurysm expansion. Expansion rate was adjusted by risk factors obtained from a database of 80 patients. Aneurysm diameters predicted with and without the risk profiles were compared with diameters measured with ultrasound for 11 patients. For this specific group of patients, local anatomy contributed 62% and the risk profile 38% to the aneurysmal expansion rate. Predictions with risk profiles resulted in smaller root mean square errors than predictions without risk profiles (2.9 vs. 4.0 mm, p < 0.01). This hybrid approach predicted aneurysmal expansion for a period of 30 months with high accuracy.
    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 03/2010; 40(1):47-53. DOI:10.1016/j.ejvs.2010.02.017 · 2.49 Impact Factor
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    O Schouten · J P van Kuijk · W J Flu ·

    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 01/2010; 51(1):281. DOI:10.1016/j.jvs.2009.11.068 · 3.02 Impact Factor
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    ABSTRACT: beta Blockers are widely used to improve the postoperative cardiac outcome in patients with coronary artery disease scheduled for noncardiac surgery. However, recently serious concerns regarding the safety of perioperative beta blockers have emerged. To assess the incidence, risk factors, and beta-blocker use associated with postoperative stroke in the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography (DECREASE) trials, we evaluated all 3,884 patients of the DECREASE trials for postoperative stroke. All cardiac risk factors and medication use were assessed. The incidence of stroke within 30 days after surgery was recorded. The incidence of postoperative stroke in the DECREASE trials was 0.46% (18 of 3,884). For the beta-blocker users, the incidence was 0.5%. All the strokes had an ischemic origin. A history of stroke was associated with a greater incidence of postoperative stroke (odds ratio [OR] 3.79, 95% confidence interval [CI] 1.2 to 11.6). Statins and anticoagulants were not associated with postoperative stroke (OR 0.85, 95% CI 0.3 to 2.4; and OR 1.27, 95% CI 0.4 to 4.6, respectively). No association with bisoprolol therapy was found (OR 1.16, 95% CI 0.4 to 3.4). In conclusion, with a low-dose bisoprolol regimen started > or =30 days before surgery, no association was observed between beta-blocker use and postoperative stroke.
    The American journal of cardiology 01/2010; 105(1):43-7. DOI:10.1016/j.amjcard.2009.08.646 · 3.28 Impact Factor
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    ABSTRACT: Despite recent advancements in perioperative care and guideline recommendations, patients undergoing vascular surgery remain at risk for perioperative cardiovascular complications. In this review, the results are summarized of the most recent studies on the effectiveness and safety of perioperative statin use for the prevention of these perioperative cardiovascular complications. Perioperative statin therapy was associated with an improvement in postoperative cardiovascular outcome and a reduction in serum lipid levels and levels of inflammation markers.
    Acta chirurgica Belgica 01/2010; 110(1):28-31. · 0.41 Impact Factor
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    Schouten O. · Boersma E. · Hoeks S.E. ·

    Journal of Vascular Surgery 12/2009; 50(6). DOI:10.1016/j.jvs.2009.10.096 · 3.02 Impact Factor
  • Olaf Schouten · Sanne E. Hoeks · Don Poldermans ·

    New England Journal of Medicine 11/2009; 361(22):2187-2188. · 55.87 Impact Factor

Publication Stats

5k Citations
822.18 Total Impact Points


  • 2010-2011
    • Reinier de Graaf Groep
      • Department of Surgery
      Delft, South Holland, Netherlands
  • 2005-2011
    • Erasmus MC
      • Department of Vascular Surgery
      Rotterdam, South Holland, Netherlands
  • 2006-2008
    • Erasmus Universiteit Rotterdam
      • Department of Cardiology
      Rotterdam, South Holland, Netherlands
    • Technische Universität München
      München, Bavaria, Germany
  • 2007
    • Leiden University
      Leyden, South Holland, Netherlands