Manfred Olschewski

Universität Freiburg, Freiburg, Lower Saxony, Germany

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Publications (77)478.47 Total impact

  • Article: Wound complications after median sternotomy: a single-centre study.
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    ABSTRACT: OBJECTIVES Sternal wound complications following median sternotomy remain a challenge in cardiac surgery. Changes in both patient profile and type of operations have been observed in recent years. Therefore, we analysed current wound healing complications after median sternotomy at our centre.METHODS All adult patients undergoing a median sternotomy between January 2009 and April 2011 were included in this retrospective analysis. Transplants and assist devices implantations were omitted. We assessed outcome, prognostic factors and microbiological results of standardized wound swabs.RESULTSIn total, 1297 patients with an average age of 67.0 ± 12.7 years were analysed. Operation types included 598 solitary coronary artery bypass grafts (CABGs), 213 solitary valve procedures, 105 CABGs with aortic valve replacement and 116 solitary aortic operations or conduit implantations. Furthermore, 255 of the remaining 265 were combined or otherwise complex procedures. Superficial healing disorders occurred in 43 patients (3.3%), while 33 (2.5%) developed deep wound complications. Six patients with sternal wound complications (7.9%) died in-hospital. In 7 patients, no pathogen was identified and the wound appeared uninfected (21% of all deep complications or 0.05% of all patients). These healing disorders were considered deep dehiscences. Patients with insulin-dependent diabetes mellitus, BMI of >40 kg/m(2) and who underwent reoperation were prone to superficial infections. Risk factors for all deep sternal wound complications were insulin-dependent diabetes mellitus, COPD and reoperation. Moreover, multivariate analysis revealed 'emergency' as an independent prognostic factor for all sternal wound complications. Microbial swabs of the sternal wound were taken in 82 of the 1297 patients (6.6%). Pathogens of the normal skin flora represented the majority of pathogens in both superficial and deep wound complications. Eight patients with deep, but only 2 patients with superficial complications suffered from polymicrobial infections. All deep polymicrobial infections involved coagulase-negative Staphylococci.CONCLUSIONS Wound complications following median sternotomy remain a challenge to cardiac surgery. Redo and emergency operations are the most important risk factors in this contemporary series. More efforts seem mandatory to decrease this arduous morbidity and the costs of prolonged treatment.
    Interactive cardiovascular and thoracic surgery 01/2013;
  • Article: Diagnosis of viral myocarditis by cardiac magnetic resonance and viral genome detection in peripheral blood.
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    ABSTRACT: In patients with acute myocarditis, viral genome can be detected in plasma and peripheral leukocytes. Its relationship with active myocardial inflammation, however, is not well understood. Myocardial edema as a feature of inflammation and myocardial necrosis or fibrosis can be frequently observed in patients with acute myocarditis by cardiovascular magnetic resonance (CMR). We assessed the association of viral genome presence in peripheral blood samples with myocardial edema and irreversible injury. We examined consecutive patients with clinically suspected myocarditis after an episode of viral illness. State-of-the-art methods were used for detecting myocardial edema and irreversible injury using CMR and viral genome applying reverse transcribed, nested polymerase chain reaction in peripheral blood samples. The specificity of viral amplification products was confirmed by automatic DNA sequencing. Of a total of 55 patients (53.5 ± 15.6 years), 21 were positive for viral genome in peripheral leukocytes. Interestingly, 18 (86 %) of these patients also showed global myocardial edema, as compared to only 7/34 (21 %) without PCR evidence for viral genome. The overall agreement between CMR criteria for edema and viral PCR was 84 %. In contrast, there was no significant relationship of viral genome presence with myocardial necrosis or scars. In patients with clinically suspected myocarditis, myocardial edema but not irreversible myocardial injury is associated with the presence of viral genome in peripheral blood.
    The international journal of cardiovascular imaging 05/2012; · 2.15 Impact Factor
  • Article: Evidence of myocardial edema in patients with nonischemic dilated cardiomyopathy.
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    ABSTRACT: Nonischemic dilated cardiomyopathy (DCM) is associated with high mortality and morbidity. Cardiovascular magnetic resonance allows for the noninvasive assessment of function, morphology, and myocardial edema. Activation of inflammatory pathways may play an important role in the etiology of chronic DCM and may also be involved in the disease progression. The purpose of our study was to assess the incidence of myocardial edema as a marker for myocardial inflammation in patients with nonischemic DCM. We examined 31 consecutive patients ( mean age, 57 ± 12 years) with idiopathic DCM. Results were compared with 39 controls matched for gender and age (mean age, 53 ± 13 years). Parameters of left ventricular function and volumes, and electrocardiogram-triggered, T2-weighted, fast spin echo triple inversion recovery sequences were applied in all patients and controls. Variables between patients and controls were compared using t tests for quantitative and χ2 tests for categorical variables. Ejection fraction (EF) was 40.3 ± 7.8% in patients and 62.6 ± 5.0% in controls (P < 0.0001). In T2-weighted images, patients with DCM had a significantly higher normalized global signal intensity ratio compared to controls (2.2 ± 0.6 and 1.8 ± 0.3, respectively, P = 0.0006), consistent with global myocardial edema. There was a significant but moderate negative correlation between signal intensity ratio in T2-weighted images and EF (-0.39, P < 0.001). Evidence shows that myocardial edema is associated with idiopathic nonischemic DCM. Further studies are needed to assess the clinical and prognostic impact of these findings.
    Clinical Cardiology 03/2012; 35(6):371-6. · 2.15 Impact Factor
  • Article: Risk factors and complications following percutaneous endoscopic gastrostomy: a case series of 1041 patients.
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    ABSTRACT: Most studies exclude patients with severe coagulation disorders or those taking anticoagulants when evaluating the outcomes of percutaneous endoscopic gastrostomy (PEG). To investigate complications and risk factors of PEG in a large clinical series including patients undergoing antiplatelet and anticoagulant therapy. During a six-year period, 1057 patients referred for PEG placement were prospectively audited for clinical outcome. Exclusion criteria and follow-up care were defined. Complications were defined as minor or severe. Uni- and multivariate analyses were used to evaluate 14 risk factors. No standardized antibiotic prophylaxis was given. A total of 1041 patients (66% male, 34% female) with the following conditions underwent PEG: neurogenic dysphagia (n=450), cancer (n=385) and others (n=206). No anticoagulants were administered to 351 patients, thrombosis prophylaxis was given to 348 while full therapeutic anticoagulation was received by 313. No increased bleeding risk was associated with patients who had above-normal international normalized ratio values (OR 0.79 [95% CI 0.08 to 7.64]; P=1.00). The total infection rate was 20.5% in patients with malignant disease, and 5.5% in those with nonmalignant disease. Severe complications occurred in 19 patients (bleeding 0.5%, peritonitis 1.3%). Cirrhosis (OR 2.91 [95% CI 1.31 to 6.54]; P=0.008), cancer (OR 2.34 [95% CI 1.33 to 4.12]; P=0.003) and radiation therapy (OR 2.34 [95% CI 1.35 to 4.05]; P=0.002) were significant predictors of post-PEG infection. The 30-day mortality rate was 5.8%. There were no procedure-related deaths. Cancer, cirrhosis and radiation therapy were predictors of infection. Post-PEG bleeding and other complications were rare events. Collectively, the data suggested that patients taking concurrent anticoagulants had no elevated risk of post-PEG bleeding.
    Canadian journal of gastroenterology = Journal canadien de gastroenterologie 04/2011; 25(4):201-6. · 1.21 Impact Factor
  • Article: Palliative cancer care: an epidemiologic study.
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    ABSTRACT: To analyze the need for palliative care in hospital patients who have cancer. Palliative care is an essential component of comprehensive cancer care and identification of palliative care needs (PCNs) of patients with cancer is a topic that has not been thoroughly studied. Data were collected prospectively from inpatients of University Medical Center Freiburg in Freiburg, Germany, with 982 hospital beds included in the study. During the observation period of 17 months, each patient discharged from a hospital ward was screened by surveying the treating physician who was responsible for dismissal about patients' PCNs based on the WHO 1990 definition of palliative care. To complete obligatory electronic discharge management, a modified dismissal form asking to classify the patient as having PCN "yes/no" had to be filled out for each patient discharged. The response rate was 96% with data for 39,849 patients that could be analyzed. A total of 6.9% of all hospital patients and 9.1% of patients older than age 65 years were considered to have PCNs. Of the 2,757 patients with PCNs, 67% (n = 1,836) had cancer. Among the 11,584 patients with cancer, 15.8% were classified as having PCNs. PCNs were particularly high in patients with head and neck cancer (28.3%), malignant melanoma (26.0%), and brain tumors (18.2%). Suffering from cancer increases the probability of developing PCNs by a factor of 3.63 (95% CI, 3.27 to 4.04). For patients with metastatic cancer, the risk of developing PCNs is increased 12-fold (odds ratio, 12.27; 95% CI, 11.07 to 13.60). Structures to provide palliative care for patients with cancer are needed.
    Journal of Clinical Oncology 02/2011; 29(6):646-50. · 18.37 Impact Factor
  • Article: Evidence for non-ischemic scarring in patients with ventricular ectopy.
    International journal of cardiology 02/2011; 147(3):482-4. · 7.08 Impact Factor
  • Article: Success of arterial revascularization determined by contrast ultrasound muscle perfusion imaging.
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    ABSTRACT: In the early postoperative evaluation of the success of arterial revascularization, ankle-brachial index (ABI) and other noninvasive tests lack reliability, especially in patients with incompressible arteries or local edema. Contrast-enhanced ultrasound (CEUS) imaging of limb muscle perfusion may be an alternative to standard tests if it detects treatment success reliably. We compared a simplified CEUS method with clinical staging, pulse volume recording (PVR), and ABI in patients with lifestyle-limiting peripheral arterial disease undergoing revascularization by percutaneous transluminal angioplasty (PTA) or bypass surgery. Patients underwent staging, PVR, ABI, and CEUS before, directly after, and 3 to 5 months after successful PTA (n = 20) or successful bypass grafting (n = 14). For CEUS, contrast agent was injected into an antecubital vein, and the time from beginning to peak intensity of contrast enhancement (TTP) in the calf muscle was measured. Successful revascularization by both PTA and bypass was associated with a significant improvement in staging, PVR, ABI, and TTP directly after intervention and at follow-up. Median ABI increased from 0.60 to 0.85 (P = .001) after PTA and from 0.36 to 0.76 (P = .003) after bypass surgery. Median TTP decreased from 45 seconds to 24 seconds (P = .015) and from 30 seconds to 27 seconds (P = .041), respectively. McNemar analysis revealed unidirectional changes in both ABI and TTP (P = .625 after PTA and P = 1.000 after bypass surgery), and equivalence analysis showed 95% confidence intervals within clinical indifference, indicating that TTP was equivalent to standard tests in detecting successful revascularization. Contrast ultrasound perfusion imaging of calf muscle after arterial revascularization may be a valuable alternative to standard noninvasive tests such as ABI or PVR to determine the success of an arterial revascularization.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 12/2010; 52(6):1531-6. · 3.52 Impact Factor
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    Article: Diagnosis of early myocarditis after respiratory or gastrointestinal tract viral infection: insights from cardiovascular magnetic resonance.
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    ABSTRACT: The diagnosis of myocarditis continues to be a challenging task in clinical practice. The purpose of our study was to investigate cardiovascular magnetic resonance imaging in the diagnostic workup of ambulatory patients with the suspicion of early myocarditis after respiratory or gastrointestinal tract viral infection. The need for accurate diagnosis of early myocarditis arises from the low diagnostic accuracy of routine clinical tests. We examined 67 consecutive patients with symptoms of weakness, palpitations, and fatigue after respiratory or gastrointestinal tract infection. We compared these patients to 31 controls. ECG-triggered, T2-weighted, fast-spin-echo triple inversion recovery sequences and delayed enhancement imaging were obtained in all patients, as well as functional parameters of left ventricular function and dimensions. In addition, in 25 patients and 10 controls, ECG-triggered, T1-weighted, multi-slice spin-echo images were obtained in axial orientation. We found a significant difference between patients with suspected myocarditis and controls in T2-global myocardial signal intensity. In addition, the ratio of global myocardial signal intensity/muscle signal intensity was 2.3 ± 0.4 in patients and 1.8 ± 0.3 in controls, which was highly significant (p < 0.001). In 23 patients, a pathological late enhancement pattern was seen, but only in one of the controls. There was no significant difference in T1-signal parameters. Cardiovascular magnetic resonance technique is able to detect early myocardial involvement after respiratory or gastrointestinal tract infection.
    Clinical Research in Cardiology 11/2010; 99(11):707-14. · 2.95 Impact Factor
  • Article: Improvement of exhausted cerebral vasoreactivity in carotid occlusion: benefit of statins?
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    ABSTRACT: In internal carotid artery occlusion (ICAO), a spontaneous increase of cerebral vasoreactivity (CVR) may occur over time. Statins are known to increase CVR. We analyzed the influence of statin treatment and other cofactors on CVR improvement in patients with ICAO. Sixty-six patients with ICAO were reexamined after 15 ± 6 months. CVR in both middle cerebral arteries was assessed by transcranial Doppler and inhalation of 7% CO(2). Pre-defined cut-off values were used to define exhausted CVR. Cofactors analyzed were: age, sex, hypertension, diabetes, statin treatment, degree of contralateral stenosis, quality of intracranial collateral flow, duration of ICAO. Mean CVR did not differ between the two studies. Twenty patients had exhausted CVR at baseline, 11 of them improved above the cut-off at follow-up (55%). Factors significantly associated with this improvement were good collateral pattern at baseline (p = 0.0065) and statin treatment (p = 0.0179). Odds ratios for improving CVR were 36.0 [95% CI 2.7-476.3] for good collateral flow and 20.0 [95% CI 1.7-238.6] for statin treatment. In conclusion, exhausted CVR frequently improves during the course of ICAO. Good collateral function and statin treatment are significantly associated with improving CVR.
    Journal of Neurology 11/2010; 258(5):791-4. · 3.47 Impact Factor
  • Article: Enhanced microparticles in ventricular assist device patients predict platelet, leukocyte and endothelial cell activation.
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    ABSTRACT: Platelet dysfunction followed by thromboembolic as well as bleeding complications are severe events in patients with ventricular assist devices (VADs). Microparticles (MP) are cell vesicles with inflammatory and coagulatory potency that are released by cells during activation and can be used as specific cell activation markers. The aim of the study was to establish MP as surrogate markers for platelet, leukocyte and endothelial activation in VAD patients predicting platelet activation and vascular inflammation. Therefore, MP from platelet, leukocyte and endothelial origin were measured in 12 patients with VAD and compared to controls. VAD patients had significantly increased levels of platelet microparticles (PMP) (VAD 1705+/-1100 cpm vs. co: 527+/-238 cpm, P=0.002), leukocyte microparticles (LMP) (VAD 43+/-16 cpm vs. co: 18+/-8 cpm, P<0.001) and endothelial microparticles (EMP) (VAD 135+/-66 cpm vs. co: 46+/-23 cpm, P<0.001) indicating enhanced vascular inflammation and pro-coagulation. Furthermore, LMP correlated well to EMP suggesting that LMP induce endothelial cell dysfunction. In conclusion, VAD patients suffer from enhanced platelet, leukocyte and endothelial activation that can be easily quantified by measuring PMP, LMP and EMP and that may help to estimate the thrombotic risk and contribute to avoid ischemic but also bleeding complications.
    Interactive cardiovascular and thoracic surgery 08/2010; 11(2):133-7.
  • Article: Complex plaques in the proximal descending aorta: an underestimated embolic source of stroke.
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    ABSTRACT: To investigate the incidence of retrograde flow from complex plaques (> or =4-mm-thick, ulcerated, or superimposed thrombi) of the descending aorta (DAo) and its potential role in embolic stroke. Ninety-four consecutive acute stroke patients with aortic plaques > or =3-mm-thick in transesophageal echocardiography were prospectively included. MRI was performed to localize complex plaques and to measure time-resolved 3-dimensional blood flow within the aorta. Three-dimensional visualization was used to evaluate if diastolic retrograde flow connected plaque location with the outlet of the left subclavian artery, left common carotid artery, or brachiocephalic trunk. Complex DAo plaques were considered an embolic source if retrograde flow reached a supra-aortic vessel that supplied the territory of visible acute and embolic retinal or cerebral infarction. Only decreasing heart rate was correlated (P<0.02) with increasing flow reversal to the aortic arch. Retrograde flow from complex DAo plaques reached the left subclavian artery in 55 (58.5%), the left common carotid artery in 23 (24.5%), and the brachiocephalic trunk in 13 patients (13.8%). Based on routine diagnostics and MRI of the ascending aorta/aortic arch, stroke etiology was determined in 57 and cryptogenic in 37 patients. Potential embolization from DAo plaques was then identified in 19 of 57 patients (33.3%) with determined and in 9 of 37 patients (24.3%) with cryptogenic stroke. Retrograde flow from complex DAo plaques was frequent in both determined and cryptogenic stroke and could explain embolism to all brain territories. These findings suggest that complex DAo plaques should be considered a new source of stroke.
    Stroke 06/2010; 41(6):1145-50. · 5.73 Impact Factor
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    Article: Four minutes for a patient, twenty seconds for a relative - an observational study at a university hospital.
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    ABSTRACT: In the modern hospital environment, increasing possibilities in medical examination techniques and increasing documentation tasks claim the physicians' energy and encroach on their time spent with patients. This study aimed to investigate how much time physicians at hospital wards spend on communication with patients and their families and how much time they spend on other specific work tasks. A non-participatory, observational study was conducted in thirty-six wards at the University Medical Center Freiburg, a 1700-bed academic hospital in Germany. All wards belonging to the clinics of internal medicine, surgery, radiology, neurology, and to the clinic for gynaecology took part in the study. Thirty-four ward doctors from fifteen different medical departments were observed during a randomly chosen complete work day. The Physicians' time for communication with patients and relatives and time spent on different working tasks during one day of work were assessed. 374 working hours were analysed. On average, a physician's workday on a university hospital ward added up to 658.91 minutes (10 hrs 58 min; range 490 - 848 min). Looking at single items of time consumption on the evaluation sheet, discussions with colleagues ranked first with 150 minutes on average. Documentation and administrative requirements took an average time of 148 minutes per day and ranked second. Total time for communication with patients and their relatives was 85 minutes per physician and day. Consequently, the available time for communication was 4 minutes and 17 seconds for each patient on the ward and 20 seconds for his or her relatives. Physicians assessed themselves to communicate twice as long with patients and sevenfold with relatives than they did according to this study. Workload and time pressure for physicians working on hospital wards are high. To offer excellent medical treatment combined with patient centred care and to meet the needs of patients and relatives on hospital wards, physicians should be given more time to focus on core clinical tasks. Time and health care management solutions to minimize time pressure are required. Further research is needed to assess quality of communication in hospital settings.
    BMC Health Services Research 04/2010; 10:94. · 1.66 Impact Factor
  • Article: Reducing the ischemic time of donor hearts will decrease morbidity and costs of cardiac transplantations.
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    ABSTRACT: With liberalization of donor eligibility criteria, donor hearts are being harvested from remote locations, increasing ischemic times. The aim of this study was to examine the effect of total ischemic time (TIT) on length of stay in the intensive care unit (LOS in ICU) and its economic consequences. The study population included recipients without prior mechanical support undergoing heart transplantation between 1998 and 2008 at a single institution. The mean age of the 72 recipients (56 men, 16 women) was 50.6 years (range 15-68 years) and the mean donor age was 41.5 years (range 11-61 years). The median TIT was 181.2 min (range 107-243) and median LOS in ICU was 11.5 days (range 3-107 days). There was a statistically significant linear relationship between TIT and LOS in ICU r(72)=0.317, P=0.004. Each 5 min and 38 s of TIT equated to one more day in ICU. An ischemic time >180 min was associated with higher LOS in ICU, renal failure, and a more frequent use of nitric oxide in our cohort. For longer distance harvesting, the reduction of TIT by the fastest possible transport (learjet, helicopter) would have economic advantages with regards to the high cost of treatment in ICU.
    Interactive cardiovascular and thoracic surgery 03/2010; 10(6):945-7.
  • Article: Four minutes for a patient, twenty seconds for a relative - an observational study at a university hospital
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    ABSTRACT: Abstract Background In the modern hospital environment, increasing possibilities in medical examination techniques and increasing documentation tasks claim the physicians' energy and encroach on their time spent with patients. This study aimed to investigate how much time physicians at hospital wards spend on communication with patients and their families and how much time they spend on other specific work tasks. Methods A non-participatory, observational study was conducted in thirty-six wards at the University Medical Center Freiburg, a 1700-bed academic hospital in Germany. All wards belonging to the clinics of internal medicine, surgery, radiology, neurology, and to the clinic for gynaecology took part in the study. Thirty-four ward doctors from fifteen different medical departments were observed during a randomly chosen complete work day. The Physicians' time for communication with patients and relatives and time spent on different working tasks during one day of work were assessed. Results 374 working hours were analysed. On average, a physician's workday on a university hospital ward added up to 658.91 minutes (10 hrs 58 min; range 490 - 848 min). Looking at single items of time consumption on the evaluation sheet, discussions with colleagues ranked first with 150 minutes on average. Documentation and administrative requirements took an average time of 148 minutes per day and ranked second. Total time for communication with patients and their relatives was 85 minutes per physician and day. Consequently, the available time for communication was 4 minutes and 17 seconds for each patient on the ward and 20 seconds for his or her relatives. Physicians assessed themselves to communicate twice as long with patients and sevenfold with relatives than they did according to this study. Conclusions Workload and time pressure for physicians working on hospital wards are high. To offer excellent medical treatment combined with patient centred care and to meet the needs of patients and relatives on hospital wards, physicians should be given more time to focus on core clinical tasks. Time and health care management solutions to minimize time pressure are required. Further research is needed to assess quality of communication in hospital settings.
    BMC Health Services Research. 01/2010;
  • Article: Improvement in coronary endothelial function is independently associated with a slowed progression of coronary artery calcification in type 2 diabetes mellitus.
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    ABSTRACT: To examine a relationship between alterations of structure and function of the arterial wall in response to glucose-lowering therapy in type 2 diabetes mellitus (DM) after a 1-year follow-up (FU). In DM (n = 22) and in healthy controls (n = 17), coronary artery calcification (CAC) was assessed with electron beam tomography and carotid intima-media thickness (IMT) with ultrasound, whereas coronary function was determined with positron emission tomography-measured myocardial blood flow (MBF) at rest, during cold pressor testing (CPT), and during adenosine stimulation at baseline and after FU. The decrease in plasma glucose in DM after a mean FU of 14 +/- 1.9 months correlated with a lower progression of CAC and carotid IMT (r = 0.48, P < or = 0.036 and r = 0.46, P < or = 0.055) and with an improvement in endothelium-related DeltaMBF to CPT and to adenosine (r = 0.46, P < or = 0.038 and r = 0.36, P < or = 0.056). After adjusting for metabolic parameters by multivariate analysis, the increases in DeltaMBF to CPT after glucose-lowering treatment remained a statistically significant independent predictor of the progression of CAC (P < or = 0.001 by one-way analysis of variance). In DM, glucose-lowering treatment may beneficially affect structure and function of the vascular wall, whereas the observed improvement in endothelium-related coronary artery function may also mediate direct preventive effects on the progression of CAC.
    European Heart Journal 11/2009; 30(24):3064-73. · 10.48 Impact Factor
  • Article: EGFR and HER2 expression in advanced biliary tract cancer.
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    ABSTRACT: To analyze the pathogenetic role and potential clinical usefulness of the epidermal growth factor receptor (EGFR) and the human epidermal growth factor receptor 2 (HER2) in patients with advanced biliary tract cancer (BTC). EGFR and HER2 expression was studied in biopsy samples from 124 patients (51% women; median age 64.8 years), with advanced BTC diagnosed between 1997 and 2004. Five micrometers sections of paraffin embedded tissue were examined by standard, FDA approved immunohistochemistry. Tumors with scores of 2+ or 3+ for HER2 expression on immunochemistry were additionally tested for HER2 gene amplification by fluorescence in situ hybridisation (FISH). 34/124 patients (27.4%) had gallbladder cancer, 47 (37.9%) had intrahepatic BTC and 43 (34.7%) had extrahepatic or perihilar BTC. EGFR expression was examined in a subset of 56 samples. EGFR expression was absent in 22/56 tumors (39.3%). Of the remaining samples expression was scored as 1+ in 12 (21.5%), 2+ in 13 (23.2%) and 3+ in 9 (16%), respectively. HER2 expression was as follows: score 0 73/124 (58.8%), score 1+ 27/124 (21.8%), score 2+ 21/124 (17%) and score 3+ 4/124 (3.2%). HER2 gene amplification was present in 6/124, resulting in an overall amplification rate of 5%. Our data suggest that routine testing and therapeutic targeting of HER2 does not seem to be useful in patients with BTC, while targeting EGFR may be promising.
    World Journal of Gastroenterology 09/2009; 15(36):4511-7. · 2.47 Impact Factor
  • Article: Effect of hormone replacement therapy on vasomotor function of the coronary microcirculation in post-menopausal women with medically treated cardiovascular risk factors.
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    ABSTRACT: The aim of this study was to evaluate the effect of hormone replacement therapy (HRT) on coronary vasomotor function in post-menopausal women (PM) with medically treated cardiovascular risk factors (RFs) in a cross-sectional and a longitudinal follow-up (FU) study. Myocardial blood flow (MBF) response to cold pressor testing (CPT) and during pharmacologically induced hyperaemia was measured with positron emission tomography in pre-menopausal women (CON), in PM with HRT and without HRT, and repeated in PM after a mean FU of 24 +/- 14 months. When compared with CON at baseline, the endothelium-related change in MBF (DeltaMBF) to CPT progressively declined in PM with HRT and without HRT (0.35 +/- 0.23 vs. 0.24 +/- 0.20 and 0.16 +/- 0.12 mL/g/min; P = 0.171 and P = 0.021). In PM without HRT and in those with HRT at baseline but with discontinuation of HRT during FU, the endothelium-related DeltaMBF to CPT was significantly less at FU than at baseline (0.05 +/- 0.19 vs. 0.16 +/- 0.12 and -0.03 +/- 0.14 vs. 0.25 +/- 0.18 mL/g/min; P = 0.023 and P = 0.001), whereas no significant change was observed in PM with HRT (0.19 +/- 0.22 vs. 0.23 +/- 0.22 mL/g/min; P = 0.453). Impaired hyperaemic MBFs when compared with CON were not significantly altered from those at baseline exam. Long-term administration of oestrogen may contribute to maintain endothelium-dependent coronary function in PM with medically treated cardiovascular RFs.
    European Heart Journal 03/2009; 30(8):978-86. · 10.48 Impact Factor
  • Article: Retrograde embolism from the descending aorta: visualization by multidirectional 3D velocity mapping in cryptogenic stroke.
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    ABSTRACT: The purpose of this study was to determine the role of plaques >or=4 mm and thrombi (complex plaques) in the descending aorta (DAo) as an embolic high-risk source for stroke. In 63 acute stroke patients scheduled for TEE, territory and embolic pattern of brain ischemia were prospectively assessed. Multidirectional 3D MRI velocity mapping of the aorta was performed to correlate the extent of retrograde diastolic blood flow with the distance of complex DAo plaques from the left subclavian artery (LSA). Embolic risk from the DAo was present for (1) retrograde flow connecting complex DAo plaques with the LSA, (2) embolic pattern of brain ischemia in a territory supplied by the left vertebral artery, and (3) stroke that could not be explained by other means. 33 of 63 patients had complex DAo plaques (distance to LSA 28.1+/-29.9 mm). Mean retrograde flow in these subjects was 26.2+/-12.3 mm. In 20 of 63 patients (31.7%) retrograde flow connected complex DAo plaques with the LSA. In 4 of these 20 patients (20%) with an embolic stroke in the territory of the brain stem, cerebellum or posterior cerebral artery, etiology could not be explained by other means. Substantial diastolic retrograde flow originating from complex plaques in the descending aorta was detected by multidirectional 3D MRI velocity mapping and constitutes a stroke mechanism that was previously not demonstrable.
    Stroke 01/2009; 40(4):1505-8. · 5.73 Impact Factor
  • Article: Electrocardiography and outcome in patients with diabetes mellitus on maintenance hemodialysis.
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    ABSTRACT: In hemodialysis, applicable guidelines recommend regular electrocardiogram (ECG) recordings. However, respective systematic evaluations are absent. Thus, the authors investigated whether routine ECG findings add prognostic information to standard risk assessment in hemodialysis. The relationship between nine common baseline ECG variables and a combined cardiovascular endpoint (CVE; cardiac death, myocardial infarction, stroke), sudden death, stroke, MI, and all-cause death in 1253 patients from the German Diabetes and Dialysis Study was evaluated. All patients were on maintenance hemodialysis, had type 2 diabetes mellitus, and received randomized treatment with atorvastatin or placebo. During 4 yr of follow-up (March 1998 to March 2004), 469 patients reached the CVE, and 617 died. After adjustment for demographics, comorbidities, and biomarkers in multivariate analysis, patients presenting without sinus rhythm were 89% more likely to die, and the risk of CVE and stroke increased by 75% and 164%, respectively, compared with patients with preserved sinus rhythm. Left ventricular hypertrophy was associated with >2-fold increase in the risk of stroke and a 60% increase in the risk of sudden death. In hemodialysis patients with type 2 diabetes mellitus, the absence of sinus rhythm is a risk indicator for CVE, stroke, and all-cause death, and left ventricular hypertrophy is associated with stroke and sudden death. Thus, routine ECG recording adds prognostic information to standard risk assessment.
    Clinical Journal of the American Society of Nephrology 01/2009; 4(2):394-400. · 5.23 Impact Factor
  • Chapter: Zwischenauswertungen und statistisches Monitoring der Ergebnisse von klinischen Studien
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    ABSTRACT: Klinische Studien werden in der Regel geplant und durchgeführt, nach Vorgaben aus der Stichprobenkalkulation (vgl. Kapitel 10) eine bestimmte Anzahl an Patienten zu rekrutieren, die über eine bestimmten Zeitraum hinweg behandelt bzw. nach der Behandlung noch weiter nachbeobachtet werden. Insbesondere in Studien, die Mortalität oder die Zeit bis zum Auftreten eines bestimmten Ereignisses als Hauptzielkriterium aufweisen und moderate Therapieunterschiede aufdecken wollen, sind hohe Patientenzahlen und damit verbundene Gesamtlaufzeiten von mehr als 5 Jahren keine Seltenheit. Solche Langzeitstudien bis zu ihrem geplanten Ende laufen zu lassen, ohne Zwischenauswertungen während des Verlaufs vorzunehmen, wird heute aus vielfältigen Gründen als nicht adäquat angesehen. Dieses Kapitel beschreibt Rationale und Vorgehensweisen beim statistischen Monitoring von Studienergebnissen im Verlauf der Studie. Dabei ist nicht das kontinuierliche Monitoring der teilnehmenden Studienzentren durch sogenannte Studienmonitore im Rahmen der Datenerhebung gemeint, das in den Kapiteln 13 und 15 behandelt wird. Statt dessen wird hier sowohl auf deskriptive Ansätze des internen organisatorischen Monitorings, als auch insbesondere auf Verfahren, die ein externes konfirmatorisches Monitoring erlauben, eingegangen. Letztere Verfahren ermöglichen in letzter Konsequenz dann auch einen vorzeitigen Abbruch einer Studie. Die wichtigen statistischen Verfahren dazu werden kurz vorgestellt und mit Beispielen aus der Literatur illustriert. Auf die Einrichtung eines externen Data Monitoring Committees zur optimalen Gewährleistung des Monitoringprozesses sowie auf Möglichkeiten der Modifikation des Studiendesigns im Rahmen sogenannter adaptiver Verfahren soll abschließend eingegangen werden.
    12/2008: pages 207-220;

Institutions

  • 2002–2012
    • Universität Freiburg
      • • Department of Cardiology and Angiology
      • • Institute of Biology I
      • • Institute of Pathology
      Freiburg, Lower Saxony, Germany
  • 1998–2011
    • Universitätsklinikum Freiburg
      • Palliative Care
      Freiburg, Lower Saxony, Germany
  • 2003–2009
    • University of California, Los Angeles
      • Department of Molecular and Medical Pharmacology
      Los Angeles, CA, USA
  • 2005–2007
    • Universitätsmedizin Göttingen
      • • Department of Cardiology and Pneumology
      • • Department of Clinical Chemistry
      Göttingen, Lower Saxony, Germany