Bas A J M de Mol

Academic Medical Center (AMC), Amsterdamo, North Holland, Netherlands

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Publications (89)364.97 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Major surgery induces a long fasting time and provokes an inflammatory response which increases the risk of infections. Nutrition given before and during surgery can avoid fasting and has been shown to increase the arginine/asymmetric dimetlhylarginine ratio, a marker of nitric oxide availability, in cardiac tissue and increased concentrations of branched chain amino acids in blood plasma. However, the effect of this new nutritional strategy on organ inflammatory response is unknown. Therefore, we studied the effect of nutrition before and during cardiac surgery on myocardial inflammatory response. In this trial, 32 patients were randomised between enteral, parenteral, and no nutrition supplementation (control) from 2 days before, during, up to 2 days after coronary artery bypass grafting. Both solutions included proteins or amino acids, glucose, vitamins, and minerals. Myocardial atrial tissue was sampled before and after revascularization and was analysed immunohistochemically, subdivided into cardiomyocytic, fatty, and fibrotic areas. Inflammatory cells, especially leukocytes, were present in cardiac tissue in all study groups. No significant differences were found in the myocardial inflammatory response between the enteral, parenteral, and control groups. In conclusion, nutrition given before and during surgery neither stimulates nor diminishes the myocardial inflammatory response in patients undergoing coronary artery bypass grafting. The trial was registered in Netherlands Trial Register (NTR): NTR2183 .
    Journal of nutrition and metabolism 08/2015; 2015(3):123158. DOI:10.1155/2015/123158
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    ABSTRACT: Background: Aortic valve stenosis (AS) induces compensatory alterations in left ventricular hemodynamics, leading to physiological and pathological alterations in coronary hemodynamics. Relief of AS by transcatheter aortic valve implantation (TAVI) decreases ventricular afterload and is expected to improve microvascular function immediately. We evaluated the effect of AS on coronary hemodynamics and the immediate effect of TAVI. Methods and results: Intracoronary pressure and flow velocity were simultaneously assessed at rest and at maximal hyperemia in an unobstructed coronary artery in 27 patients with AS before and immediately after TAVI and in 28 patients without AS. Baseline flow velocity was higher and baseline microvascular resistance was lower in patients with AS as compared with controls, which remained unaltered post-TAVI. In patients with AS, hyperemic flow velocity was significantly lower as compared with controls (44.5±14.5 versus 54.3±18.6 cm/s; P=0.04). Hyperemic microvascular resistance (expressed in mm Hg·cm·s(-1)) was 2.10±0.69 in patients with AS as compared with 1.80±0.60 in controls (P=0.096). Coronary flow velocity reserve in patients with AS was lower, 1.9±0.5 versus 2.7±0.7 in controls (P<0.001). Improvement in coronary hemodynamics after TAVI was most pronounced in patients without post-TAVI aortic regurgitation. In these patients (n=20), hyperemic flow velocity increased significantly from 46.24±15.47 pre-TAVI to 56.56±17.44 cm/s post-TAVI (P=0.003). Hyperemic microvascular resistance decreased from 2.03±0.71 to 1.66±0.45 (P=0.050). Coronary flow velocity reserve increased significantly from 1.9±0.4 to 2.2±0.6 (P=0.009). Conclusions: The vasodilatory reserve capacity of the coronary circulation is reduced in AS. TAVI induces an immediate decrease in hyperemic microvascular resistance and a concomitant increase in hyperemic flow velocity, resulting in immediate improvement in coronary vasodilatory reserve.
    Circulation Cardiovascular Interventions 08/2015; 8(8):e002443. DOI:10.1161/CIRCINTERVENTIONS.114.002443 · 6.22 Impact Factor
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    ABSTRACT: Early recognition and, where possible, avoidance of risk factors that contribute to the development of poststernotomy mediastinitis (PSM) form the basis for successful prevention. Once the presence of PSM is diagnosed, the known risk factors have been shown to have limited influence on management decisions. Evidence-based knowledge on treatment decisions, which include the extent and type of surgical intervention (other than debridement), timing and others is available but has not yet been incorporated into a classification on management decisions regarding PSM. Ours is a first attempt at developing a classification system for management of PSM, taking the various evidence-based reconstructive options into consideration. The classification is simple to introduce (there are four Types) and relies on the careful establishment of two variables (sternal stability and sternal bone viability and stock) prior to deciding on the best available reconstructive option. It should allow better insight into why treatment decisions fail or have to be altered and will allow better comparison of treatment outcomes between various institutions.
    Journal of Cardiothoracic Surgery 11/2014; 9(1):179. DOI:10.1186/s13019-014-0179-4 · 1.03 Impact Factor
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    ABSTRACT: To evaluate our results of valve-sparing aortic root replacement and associated (multiple) valve repair. From September 2003 to September 2013, 97 patients had valve-sparing aortic root replacement procedures. Patient records and preoperative, postoperative and recent echocardiograms were reviewed. Median age was 40.3 (range: 13.4-68.6) years and 67 (69.1%) were male. Seven (7.2%) patients were younger than 18 years, the youngest being 13.4 years. Fifty-four (55.7%) had Marfan syndrome, 2 (2.1%) other fibrous tissue diseases, 15 (15.5%) bicuspid aortic valve and 3 (3.1%) had earlier Fallot repair. The reimplantation technique was used in all, with a straight vascular prosthesis in 11 (26-34 mm) and the Valsalva prosthesis in 86 (26-32 mm). Concomitant aortic valve repair was performed in 43 (44.3%), mitral valve repair in 10 (10.3%), tricuspid valve repair in 5 (5.2%) and aortic arch replacement in 3 (3.1%). Mean follow-up was 4.2 ± 2.4 years. Follow-up was complete in all. One 14-year old patient died 1.3 years post-surgery presumably of ventricular arrhythmia. One patient underwent reoperation for aneurysm of the proximal right coronary artery after 4.9 years and 4 patients required aortic valve replacement, 3 of which because of endocarditis after 0.1, 0.8 and 1.3 years and 1 because of cusp prolapse after 3.8 years. No thrombo-embolic complications occurred. Mortality, root reoperation and aortic regurgitation were absent in 88.0 ± 0.5% at 5-year follow-up. Results of valve-sparing root replacement are good, even in association with a high incidence of concomitant valve repair. Valve-sparing aortic root replacement can be performed at a very young age as long as an adult size prosthesis can be implanted.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 04/2014; 47(2). DOI:10.1093/ejcts/ezu167 · 3.30 Impact Factor
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    ABSTRACT: To evaluate long-term results of tracheoplasty using autologous pericardial patch and strips of costal cartilage for relieving severe long-segment tracheal stenosis. Data were collected retrospectively by clinical chart review. Between 1995 and 2013, 21 patients underwent tracheoplasty. Follow-up was performed by outpatient chart review; otherwise, referring physicians and parents were contacted and asked to fill in a questionnaire. Median age at the time of operation was 0.9 (range 0.5-44) years. Aetiology of tracheal stenosis was double aortic arch in 9 patients, right arch with a left ductus in 3, innominate artery compression in 1 patient, complete tracheal rings in 7, 3 of whom with pulmonary artery sling and 2 with agenesis of one lung, and other causes in 1 patient. Previous surgery was performed in 6 (29%) patients. Patch tracheoplasty was performed using autologous pericardial patch and external stenting using costal cartilage. Major complications were mediastinitis and patch dehiscence in 2 patients, 2 patients needed tracheal cannula and 1 patient had stent implantation. Three (14%) patients died in the late postoperative period: 1 patient died of sepsis, 1 had patch dehiscence and 1 erosion of tracheal stent and consequently intractable bleeding. Follow-up was 6.1 ± 2.7 years (0.75-10 years). At follow-up, 2 (11%) patients were still symptomatic, 4 (22%) had occasionally mild symptoms and 12 (67%) were free of symptoms. Treatment for severe tracheal stenosis remains challenging. With tracheoplasty using autologous pericardial patch and strips of costal cartilage, long and narrow tracheal stenosis can be repaired. There are no limitations as to the length and location and severity of the stenosis. Tracheoplasty is associated with a high complication rate. A multidisciplinary approach is mandatory to ensure favourable long-term outcomes.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 03/2014; 47(1). DOI:10.1093/ejcts/ezu101 · 3.30 Impact Factor
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    ABSTRACT: Patients with atrial fibrillation (AF) with enlarged atria or previous pulmonary vein isolation (PVI) are challenging patients for catheter ablation. Thoracoscopic surgery is an effective treatment for these patients but comes at the cost of an increase in adverse events. Recently, electrophysiological (EP) guided approaches to thoracoscopic surgery have been described which consist of EP guidance by measurement of conduction block across ablation lines. In this study we describe the efficacy and safety of EP-guided thoracoscopic surgery for AF in patients with enlarged atria and/or prior failed catheter ablation. A total of 72 patients were included. Two different approaches to EP-guided thoracoscopic surgery were implemented: epicardial or endocardial EP-guidance at the time of surgery. Residual intraoperative conduction requiring additional ablation was detected with epicardial or endocardial mapping techniques in 50% and 11%, respectively. Additional epicardial or endocardial ablation was performed until bidirectional block was confirmed. Follow-up consisted of an ECG and a 24h Holter at 3, 6 and 12months after the procedure. A total of 57 patients (79%) had freedom of AF and were off anti-arrhythmic drugs at one year follow-up (30 paroxysmal (83%), 27 persistent AF (75%)). Adverse events occurred in 13 patients (6 major). None of our patients died and all events were reversible. EP-guidance of thoracoscopic surgery can be safely performed both epicardially and endocardially and is associated with a high rate of long-term maintenance of sinus rhythm in patients with enlarged atria and/or a previously failed ablation.
    International journal of cardiology 02/2014; 173(2). DOI:10.1016/j.ijcard.2014.02.043 · 4.04 Impact Factor
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    ABSTRACT: To evaluate incidence and results of surgical intervention for neoaortic root pathology following arterial switch operation (ASO) for transposition of the great arteries (TGA). Between April 1996 and August 2013, 12 patients underwent reoperation for neoaortic root dilatation (ARD) and/or neoaortic valve regurgitation (AR). Maximal aortic sinus and annulus diameter Z-scores were recorded. Original diagnoses were TGA/IVS (6), TGA/ventricular septal defect (VSD) (4) and Taussig-Bing anomaly (2) with ASO at a median age of 0.1 (range: 0-10.6) years. Age at ASO, VSD and complex TGA were reviewed as possible risk factors for reoperation. Twelve patients with tricuspid neoaortic valves underwent 15 root operations; indications were root dilatation (4) and root dilatation with AR (8). Median age was 18.0 (3.0-29.0) years at first reoperation. Median aortic root Z-score at reoperation was 6.33 (range: 3.84-12.15). Procedures were: Bentall procedure (6), aortic valve replacement (2), neoaortic valve plasty (1), supracoronary tube (1) and switch-back operation (2). Mean follow-up was 7.0 ± 5.7 years and complete. No mortality occurred. One patient had two reoperations for late endocarditis. Technical difficulties were encountered related to specific anatomy post-ASO concerning coronary anatomy, poor exposure and thin-walled aorta at the site of pulmonary artery bifurcation after Lecompte manoeuvre. Valve sparing surgery seemed not feasible due to specific anatomy of the neoaortic root and valve. No risk factors for reoperation could be identified. After ASO, surgery for neoaortic root pathology may become necessary when follow-up is long enough and regardless of primary diagnosis or other risk factors. Redo neoaortic surgery can be performed with low risk taking into account the specific technical difficulties.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 02/2014; 46(3). DOI:10.1093/ejcts/ezu026 · 3.30 Impact Factor
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    ABSTRACT: Arterial blood pressure and echocardiography may provide useful physiological information regarding cardiac support in patients with continuous-flow Left Ventricular Assist Devices (cf-LVADs). We investigated the accuracy and characteristics of non-invasive blood pressure during cf-LVAD support. Noninvasive arterial pressure waveforms were recorded with Nexfin (BMEYE, Amsterdam, Netherlands). First these measurements were validated simultaneous with invasive arterial pressures in 29 ICU patients. Next, the association between blood pressure responses and echocardiographically derived left ventricular end diastolic dimensions (LVEDD), systolic dimensions (LVESD) and shortening fraction (LVSF) were determined during pump speed change procedures in 30 outpatients. Non-invasive arterial blood pressure waveforms by the Nexfin monitor were slightly underestimated during cf-LVAD support. Noninvasive-invasive differences (mean ± SD) of systolic-, diastolic-, mean - and pulse pressure were -7.6 ± 5.8, -7.0 ± 5.2, -6.9 ± 5.1 and -0.6 ± 4.5 mmHg respectively (all < 10%). These blood pressure responses did not correlate with LVEDD, LVESD or LVSF, while LVSF correlated weakly with both pulse pressure (r=0.24;p=0.005) and dPart/dtmax (r=0.25;p=0.004). The dicrotic notch in the pressure waveform was a better predictor of aortic valve opening (AUC=0.87) than pulse pressure (AUC=0.64) and dPart/dtmax (AUC=0.61). Patients with partial support rather than full support at 9000 rpm had a significant rise in systolic, pulse pressure and dPart/dtmax without changes in echocardiographic measures, yet it reflected blood pressure responses to pump speed changes. Blood pressure measurements by Nexfin were reliable and may thereby act as a compliment to the assessment of the cf-LVAD patient.
    ASAIO journal (American Society for Artificial Internal Organs: 1992) 01/2014; 60(2). DOI:10.1097/MAT.0000000000000033 · 1.52 Impact Factor
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    ABSTRACT: Echocardiography may miss prosthetic heart valve (PHV) endocarditis which advocates for novel imaging techniques to improve diagnostic accuracy and patient outcome. The purpose of this study was to determine the complementary diagnostic value of cardiac computed tomography angiography (CTA) to the clinical routine workup including transthoracic and transesophageal echocardiography (TTE/TEE) in patients with suspected PHV endocarditis and its impact on patient treatment. A diagnostic prospective cross-sectional study was chosen as design. Besides clinical routine workup (including TTE/TEE), CTA was performed to assess its diagnostic accuracy and complementary diagnostic/therapeutic value. For the diagnostic accuracy, the reference standard was surgical findings or clinical follow-up. To determine the complementary diagnostic/therapeutic value an expert-panel was used as reference standard. Twenty-eight patients were included. CTA resulted in a major diagnostic change in six patients (21 %) mainly driven by novel detection of mycotic aneurysms by CTA. Furthermore, treatment changes occurred in seven patients (25 %) compared to clinical routine workup. Diagnostic accuracy of routine clinical workup plus CTA was superior to clinical routine workup alone for the detection of PHV endocarditis in general, vegetations and peri-annular extension. This study demonstrates that CTA and clinical workup including TTE and TEE are complementary in patients with PHV endocarditis. Therefore, CTA imaging has to be considered after clinical routine workup in patients with a high suspicion on PHV endocarditis.
    The international journal of cardiovascular imaging 11/2013; 30(2). DOI:10.1007/s10554-013-0335-2 · 1.81 Impact Factor
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    Journal of the American College of Cardiology 10/2013; 62(18). DOI:10.1016/j.jacc.2013.08.1471 · 16.50 Impact Factor
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    Journal of the American College of Cardiology 10/2013; 62(18). DOI:10.1016/j.jacc.2013.08.1470 · 16.50 Impact Factor
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    ABSTRACT: The use of long-term mechanical circulatory support (MCS) for heart failure by means of implanted continuous-flow left ventricular assist devices (cf-LVADs) will increase, either to enable recovery or to provide a destination therapy. The effectiveness and user-friendliness of MCS will depend on the development of near-physiologic control strategies for which accurate estimation of pump flow is essential. To provide means for the assessment of pump flow, this study presents pump models, estimating pump flow (Qlvad) from pump speed (n) and pressure difference across the LVAD (Δplvad) or power uptake (P). The models are evaluated for the axial-flow LVADs HeartAssist5 (HA5) and HeartMate II (HMII), and for a centrifugal pump, the HeartWare (HW). For all three pumps, models estimating Qlvad from Δplvad only is capable of describing pump behavior under static conditions. For the axial pumps, flow estimation from power uptake alone was not accurate. When assuming an increase in pump flow with increasing power uptake, low pump flows are overestimated in these pumps. Only for the HW, pump flow increased linearly with power uptake, resulting in a power-based pump model that estimates static pump flow accurately. The addition of pressure head measurements improved accuracy in the axial cf-LVAD estimation models.
    ASAIO journal (American Society for Artificial Internal Organs: 1992) 07/2013; 59(4):420-426. DOI:10.1097/MAT.0b013e3182937a3a · 1.52 Impact Factor
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    ABSTRACT: OBJECTIVES: We evaluated 30-day and 1-year clinical outcomes after percutaneous or surgical coronary revascularisation in patients with unprotected left main coronary artery (ULMCA)-related acute myocardial infarction (AMI). DESIGN: Single-centre registry. PATIENTS: Between January 1998 and December 2008, 84 patients with ULMCA-related AMI underwent revascularisation treatment in our institution (55 underwent percutaneous coronary intervention (PCI), 29 underwent coronary artery bypass graft surgery (CABG)). METHODS: One-year clinical follow-up was obtained for all patients. Univariable and multivariable analyses were performed to find predictors for 30-day mortality and treatment allocation. RESULTS: In the PCI-group, all-cause mortality was 64% at 30 days and 69% at 1 year. In the CABG-group, this was 24% at 30 days and 1 year. Independent predictors of 30-day mortality were cardiogenic shock (HR 2.83), thrombolysis in MI (TIMI) 0/1 flow (HR 2.27) and diabetes mellitus (HR 2.65). Treatment allocation to PCI was primarily determined by TIMI 0/1 flow on baseline angiogram (OR 150). In patients with TIMI 2/3 flow on initial angiogram, treatment allocation was determined by presentation with cardiogenic shock (OR 5.61), year of inclusion (OR 1.72), and distal/bifurcation disease (OR 0.11). CONCLUSIONS: Thirty-day mortality was high in patients presenting with an ULMCA-related AMI, both in the PCI as in the CABG-treatment group. Presentation with cardiogenic shock, TIMI 0/1 flow on initial angiogram and diabetes mellitus were independently predicting of 30-day mortality, whereas treatment allocation was primarily determined by presentation with TIMI 0/1 flow.
    Heart (British Cardiac Society) 03/2013; 99(10). DOI:10.1136/heartjnl-2012-303402 · 5.60 Impact Factor
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    ABSTRACT: Objectives: The aim of our study was to investigate early mortality after cardiac surgery and to determine the most adequate follow-up period for the evaluation of mortality rates. Methods: Information on all adult cardiac surgery procedures in 10 of 16 cardiothoracic centres in Netherlands from 2007 until 2010 was extracted from the database of Netherlands Association for Cardio-Thoracic Surgery (n = 33 094). Survival up to 1 year after surgery was obtained from the national death registry. Survival analysis was performed using Kaplan-Meier and Cox regression analysis. Benchmarking was performed using logistic regression with mortality rates at different time points as dependent variables, the logistic EuroSCORE as covariate and a random intercept per centre. Results: In-hospital mortality was 2.94% (n = 972), 30-day mortality 3.02% (n = 998), operative mortality 3.57% (n = 1181), 60-day mortality 3.84% (n = 1271), 6-month mortality 5.16% (n = 1707) and 1-year mortality 6.20% (n = 2052). The survival curves showed a steep initial decline followed by stabilization after ∼60-120 days, depending on the intervention performed, e.g. 60 days for isolated coronary artery bypass grafting (CABG) and 120 days for combined CABG and valve surgery. Benchmark results were affected by the choice of the follow-up period: four hospitals changed outlier status when the follow-up was increased from 30 days to 1 year. In the isolated CABG subgroup, benchmark results were unaffected: no outliers were found using either 30-day or 1-year follow-up. Conclusions: The course of early mortality after cardiac surgery differs across interventions and continues up to ∼120 days. Thirty-day mortality reflects only a part of early mortality after cardiac surgery and should only be used for benchmarking of isolated CABG procedures. The follow-up should be prolonged to capture early mortality of all types of interventions.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 03/2013; 44(5). DOI:10.1093/ejcts/ezt119 · 3.30 Impact Factor
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    ABSTRACT: Background: Apart of medical reasons, a definitive diagnosis of malignant mesothelioma may be required as a basis for a claim of financial compensation although a pathological source of conclusive evidence is missing. Clinical assessment of all available data is then the only option to come to a final conclusion. We evaluated the diagnostic work-up of a large cohort of Dutch patients who applied for financial compensation due to mesothelioma. We determined how often a pathological or clinical diagnosis can be made, and which factors are associated with making the final diagnosis malignant mesothelioma. Methods: A flow diagram of the diagnostic work-up was constructed for patients that applied to the Dutch institute for asbestos victims between 2005 and 2008 (N=1498). Both pathological and clinical factors that may influence the diagnostic outcome were assessed. Results: In 97 of the 1498 patients (6%) no pathologic diagnosis could be established because of an uncertain diagnosis (N=54), inadequate (N=22) or unavailable tumor samples (N=21). A final pathological diagnosis of malignant mesothelioma could most often be made when biopsy samples were available compared to those in whom only cytological material was available. In patients in who no conclusive diagnosis could be made, clinical assessment was performed. Eighty percent of patients (66/83) who were clinically assessed were considered to have mesothelioma. None of the clinical features analyzed were strongly associated with a confirmed diagnosis of malignant mesothelioma. Discussion: Our study shows that only in a small number of the patients who applied no pathologic diagnosis could be obtained. Based on judgment of clinical experts in the majority of these cases a near to certain diagnosis could be made. Moreover, it is reasonable to obtain biopsy material from patients to increase the chance to obtain a confirmed diagnosis. Therefore, it is important to refer patients early for diagnostic procedures.
    Lung cancer (Amsterdam, Netherlands) 02/2013; 80(2). DOI:10.1016/j.lungcan.2013.01.012 · 3.96 Impact Factor
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    ABSTRACT: Loss of body tissue resulting in undernutrition can be caused by reduced food intake, altered metabolism, ageing, and physical inactivity. The predominant cause of undernutrition before cardiac operations is unknown. First, we explored the association of reduced food intake and inactivity with undernutrition in patients before elective cardiac operations. Second, we assessed if adding these reversible, cause-based items to the nutritional screening process improved diagnostic accuracy. A prospective observational study was performed. Undernutrition was defined by low fat-free mass index (LFFMI) measured by bioelectrical impedance spectroscopy and/or unintended weight loss (UWL). Reduced food intake was defined as the patient having a decreased appetite over the previous month. Patients admitted to hospital preoperatively were assumed to be less physically active than patients awaiting cardiac operations at home. Using these data, we developed a new tool and compared this with an existing cardiac surgery-specific tool (Cardiac Surgery-Specific Malnutrition Universal Screening Tool [CSSM]). A total of 325 patients who underwent open cardiac operations were included. Reduced food intake and inactivity were associated with undernutrition (odds ratio [OR], 4.2; 95% confidence interval [CI], 2.1-8.5 and OR, 2.0; 95% CI, 1.0-4.0). Reduced food intake and inactivity were integrated with body mass index (BMI) and UWL into a new scoring system: the Cardiac Surgery-Specific Undernutrition Screening Tool (CSSUST). Sensitivity in identification of undernourished patients was considerably higher with the CSSUST (90%) than with the CSSM (71%) (receiver operating characteristic [ROC] curve-based area under the curve [AUC], 0.79; 95% CI, 0.73-0.86 and ROC AUC, 0.71; 95% CI, 0.63-0.80). Results suggest that reduced food intake and inactivity partly explain undernutrition before cardiac operations. Our new cause-based CSSUST, which includes reduced food intake and inactivity, is superior to existing tools in identifying undernutrition in patients undergoing cardiac operations.
    The Annals of thoracic surgery 02/2013; 95(2):642-7. DOI:10.1016/j.athoracsur.2012.08.119 · 3.85 Impact Factor
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    ABSTRACT: We considered a mathematical model to investigate changes in geometric and hemodynamic indices of left ventricular function in response to changes in myofiber contractility and myocardial tissue stiffness during rotary blood pump support. Left ventricular assistance with a rotary blood pump was simulated based on a previously published biventricular model of the assisted heart and circulation. The ventricles in this model were based on the one-fiber model that relates ventricular function to myofiber contractility and myocardial tissue stiffness. The simulations showed that indices of ventricular geometry, left ventricular shortening fraction, and ejection fraction had the same response to variations in myofiber contractility and myocardial tissue stiffness. Hemodynamic measures showed an inverse relation compared with geometric measures. Particularly, pulse pressure and arterial dP/dt(max) increased when myofiber contractility increased, whereas increasing myocardial tissue stiffness decreased these measures. Similarly, the lowest pump speed at which the aortic valve remained closed increased when myofiber contractility increased and decreased when myocardial tissue stiffness increased. Therefore, simultaneous monitoring of hemodynamic parameters and ventricular geometry indirectly reflects the status of the myocardial tissue. The appropriateness of this strategy will be evaluated in the future, based on in vivo studies.
    Artificial Organs 12/2012; 37(6). DOI:10.1111/j.1525-1594.2012.01548.x · 2.05 Impact Factor
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    Henryk Jan Te Kolsté · Wilson Wan Lung Li · Bas A.J. M. de Mol
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    ABSTRACT: To the Editor: With much interest we read the recent article of Funakoshi and colleagues,1 suggesting superior long-term outcomes for patients with infective endocarditis after early surgical treatment relative to a purported conventional treatment strategy. Although the results seem in line with general consensus, several methodologic issues arise, affecting the validity of the study’s conclusions. First, we would like to comment on the definition of the study groups. The conventional treatment group includes patients who have been treated with antibiotics only, as well as patients who have been operated on at a later stage. In our opinion, these patients should not be combined into a single treatment group. To illustrate this, the in-hospital mortality is 5% for both the early and late surgical groups. On the other hand, the mortality of the conventional treatment group seems higher (5% vs 13%; P = .08), possibly caused by unfavorable results in the nonsurgical group. It would have been more informative to have 3 groups for comparison: patients after early surgical treatment, patients after late surgical treatment, and patients who have been treated with antibiotics only. Correspondingly, it is problematic to interpret the result of the propensity-matched comparison, because it remains unclear how many patients in the conventional treatment group have undergone surgical treatment. To assess the role of early surgical treatment in infective endocarditis adequately, it would be more instructive to compare the results of early surgical treatment with those of late surgical treatment. Second, the chosen period of 14 days after the initial diagnosis as cutoff point for early versus late surgery seems questionable. Several studies show that the risk of embolic events dramatically drops as early as 1 week of antibiotic treatment.2 Accordingly, the European guidelines3 on this specific subject advise that early surgical treatment should be performed within several days after the diagnosis, instead of after 14 days, whenever there is an indication for early operation. Another point of concern is the postoperative neurologic outcome. Among patients who had complicating stroke on admission, 30% had either cerebral infarction or hemorrhage after early surgical treatment, compared with 8% in the late operation group. Facing these results, one should keep in mind the recommendations by the Society of Thoracic Surgeons Clinical Practice Guidelines4 to delay surgery for at least 4 weeks if possible for patients who have had a major ischemic stroke or any intracranial hemorrhage. Finally, we are interested in the results of intraoperative valve cultures and pathologic examination of infected valves. How many patients showed traces of active endocarditis during surgery? Was this associated with the fairly high risk of reoperation during follow-up (9%-12%)? In conclusion, we could say that this study shows a lower in-hospital mortality in the early surgery group at the expense of worse neurologic outcomes. We think that if one does not know the indications for early surgery, a judgment on the outcomes of surgery will be questionable. Referring to these concerns, we consider the data presented not convincing for dropping a patient-tailored approach in favor of a priori early surgical treatment.
    The Journal of thoracic and cardiovascular surgery 12/2012; 144(6):1537-8. DOI:10.1016/j.jtcvs.2012.03.090 · 4.17 Impact Factor
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    Journal of the American College of Cardiology 10/2012; 60(17). DOI:10.1016/j.jacc.2012.08.897 · 16.50 Impact Factor
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    Journal of the American College of Cardiology 10/2012; 60(17). DOI:10.1016/j.jacc.2012.08.926 · 16.50 Impact Factor

Publication Stats

1k Citations
364.97 Total Impact Points


  • 2014
    • Academic Medical Center (AMC)
      Amsterdamo, North Holland, Netherlands
  • 2008–2014
    • Academisch Medisch Centrum Universiteit van Amsterdam
      • • Department of Cardiology and Cardio-thoracic Surgery
      • • Department of Pathology
      • • Academic Medical Center
      Amsterdamo, North Holland, Netherlands
  • 2003–2014
    • University of Amsterdam
      • Faculty of Medicine AMC
      Amsterdamo, North Holland, Netherlands
  • 2012
    • University Medical Center Utrecht
      Utrecht, Utrecht, Netherlands
  • 2007–2012
    • Technische Universiteit Eindhoven
      • Department of Biomedical Engineering
      Eindhoven, North Brabant, Netherlands