Andreas Frech

University of Innsbruck, Innsbruck, Tyrol, Austria

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Publications (7)17.64 Total impact

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    ABSTRACT: Cardiovascular morbidity is high among patients with peripheral arterial occlusive disease (PAOD). The aim of this study was to evaluate the ability of ischemia-modified Albumin (IMA), N-terminal proBNP (NT-proBNP), and high-sensitive cardiac Troponin T (hs-cTnT) to predict cardiovascular complications in male patients with Fontaine stage II PAOD.
    09/2014;
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    ABSTRACT: The aim of this study was to compare the accuracy of (123)I-MIBG SPECT/CT with that of (68)Ga-DOTATOC PET/CT for staging extraadrenal paragangliomas (PGL) using both functional and anatomical images (i.e. combined cross-sectional imaging) as the reference standards.
    European journal of nuclear medicine and molecular imaging 08/2014; · 5.11 Impact Factor
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    ABSTRACT: Despite medical treatment, one third of patients with uncomplicated type B aortic dissections experience severe late complications. The aim of this study was to identify patients at high risk of mortality during follow-up. A total of 183 patients with acute Stanford type B dissection were treated in one of the university hospitals (Aachen [Germany], Maastricht [The Netherlands], and Innsbruck [Austria]) between 1997 and 2010. Records indicated that 120 patients were treated conservatively. Of these patients, 16 were lost to follow-up. The maximum diameter, extent of the dissection, and patency of the side branches were determined from computed tomography angiography data. Survival and treatment failure were analyzed by univariate and multivariate Cox regression analysis. The univariate analysis investigated the influence of aortic diameter (≥41 vs <41 mm) on survival, and the multivariate analysis investigated the influence of aortic diameter, age, sex, and surgery on survival. During the follow-up period, the initial treatment was converted to surgical treatment in 21 patients (20.2%). Sixteen of the 104 patients (15.4%) died after a mean of 845.5 ± 805.9 days. The mean maximum aortic transversal diameter at admission was 41.2 ± 8.7 mm. The multivariate analysis identified aortic diameter (P = .004; hazard ratio, 1.07) and age (P = .038; hazard ratio, 1.05) as risk factors that significantly reduce survival. Our study revealed both early aortic dilatation and older age as risk factors for increased mortality after conservative treatment of type B dissection.
    The Journal of thoracic and cardiovascular surgery 04/2014; · 3.41 Impact Factor
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    ABSTRACT: Purpose 18F-Fluoro-l-dihydroxyphenylalanine (18F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by 68Ga-DOTA-Tyr3-octreotide (68Ga-DOTA-TOC) PET. Therefore, we compared 68Ga-DOTA-TOC and 18F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. Methods A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with 68Ga-DOTA-TOC PET and 18F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUVmax) of each functional imaging modality in concordant tumour lesions was measured. Results Compared with anatomical imaging, 68Ga-DOTA-TOC PET and 18F-DOPA PET each had a per-patient and per-lesion detection rate of 100 % in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of 68Ga-DOTA-TOC was 100 % and that of 18F-DOPA PET was 56.0 %. Overall, 68Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and 18F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of 68Ga-DOTA-TOC PET was 100 % (McNemar, P < 0.5), and that of 18F-DOPA PET was 71.1 % (McNemar, P < 0.001). The SUVmax (mean ± SD) of all 32 concordant lesions was 67.9 ± 61.5 for 68Ga-DOTA-TOC PET and 11.8 ± 7.9 for 18F-DOPA PET (Mann-Whitney U test, P < 0.0001). Conclusion 68Ga-DOTA-TOC PET may be superior to 18F-DOPA PET and diagnostic CT in providing valuable information for pretherapeutic staging of extra-adrenal PGL, particularly in surgically inoperable tumours and metastatic or multifocal disease.
    European journal of nuclear medicine and molecular imaging 12/2013; 40(12). · 5.11 Impact Factor
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    ABSTRACT: Due to the systemic nature of atherosclerosis, the prevalence of coronary artery disease (CAD) is high in patients with peripheral arterial disease (PAD). A biochemical assay for assessing cardiac risk might improve clinical evaluation of PAD patients. The aim of this study was to investigate whether a new high-sensitivity cardiac Troponin T (hs-cTnT) assay can predict exercise-induced myocardial ischemia in PAD patients without clinical signs of CAD. Sixty-eight ambulatory patients with Fontaine stage II PAD underwent treadmill stress testing to maximum walking distance. Myocardial ischemia was assessed using a 2-lead Holter ECG and ST-segment depression of ≥ 0.2 mV was considered significant. Hs-cTnT was measured from serum samples taken at baseline as well as 5, 10 and 30 min after exercise. Hs-cTnT baseline levels were significantly higher (19.3 ng/L (5.0; 20.2 ng/L) vs. 6.6 ng/L (4.4; 9.4 ng/L); p=0.037) and increase of serum levels 5 min after cessation of exercise was more pronounced (1.09 ng/L (0.23; 1.80 ng/L) vs. 0.22 ng/L (-0.1; 0.65 ng/L), p=0.032) in ECG positive patients compared to individuals with normal ECG. Logistic regression analysis identified the baseline hs-cTnT serum level as an independent risk factor for developing significant exercise-induced ST-segment depression (odds ratio 1.2 per 1-unit increase, p=0.015). In patients with PAD, exercise-induced myocardial ischemia is associated with elevated baseline levels and a significant early increase of hs-cTnT serum levels.
    Clinica chimica acta; international journal of clinical chemistry 05/2012; 413(19-20):1678-82. · 2.54 Impact Factor
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    ABSTRACT: Constant-load treadmill testing is frequently used to estimate walking ability of patients with peripheral arterial disease and to assess changes in functional capacity following therapeutic interventions or through disease progression. The value of this test has frequently been disputed based on doubts concerning its reproducibility. The aim of this study was to investigate the reliability of treadmill testing at a speed of 3 km/h and a constant inclination of 12%. Sixty-eight patients with stable peripheral arterial disease who were familiar with treadmill testing underwent two sessions of walking exercise at 3 km/h and 12% inclination within three weeks. Initial claudication distance (ICD) and maximum walking distance (MWD) on the treadmill as well as reported walking distances on level ground at individual speed were recorded. Correlation coefficients of 0.8 and within-subject variation coefficients of 15% for ICD and 13% for MWD demonstrated low variability of walking distances between visits. No learning effects were observed. Intra-class correlation coefficients of 0.78 for ICD and 0.83 for MWD proved good reproducibility of treadmill testing. Correlation of measured and reported walking distances was poor. Constant-load treadmill testing at 3km/h and 12% inclination is a well reproducible method to investigate walking capacity of patients with stable intermittent claudication who are familiar with this test method. From treadmill walking distances, no conclusions should be drawn concerning the actual walking range of the patient.
    International angiology: a journal of the International Union of Angiology 04/2012; 31(2):150-5. · 1.46 Impact Factor
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    ABSTRACT: Abdominal aortic aneurysms represent both an individual risk of mortality and a socioeconomic burden for health care systems worldwide, but screening is not performed in all countries. Here, the authors summarize the pros and cons of screening to reduce abdominal aortic aneurysm-related mortality.
    Journal of primary care & community health. 04/2012; 3(2):142-147.