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V Klauss

Publications and source records attributed to V Klauss.

At least 19 recordsLinked to original sources

Reproducibility of neointima quantification with motorized intravascular ultrasound pullback in stented coronary arteries.

BACKGROUND: Intravascular ultrasound (IVUS) imaging has shown excellent reproducibility immediately after coronary stent implantation. However, the variability of measurements in lesions late after stent implantation, when neointima formation is present, has not been studied. Neointimal tissue is generally low echogenic and thus difficult to quantify. We therefore sought to analyze the reproducibility of morphometric measurements late after stent implantation. METHODS AND RESULTS: Fifty consecutive patients were investigated 6 months after Palmaz-Schatz stent implantation (motorized catheter pullback 0.5 mm/s). Two experienced investigators independently identified the stent area, lumen area, and neointimal area at different sites within the stent. Planimetric measurements were performed with commercially available software. Correlation coefficient and mean difference for corresponding measurements were calculated for the intraobserver and interobserver comparisons. Variability for the intraobserver and interobserver comparisons was similar. Observer agreement regarding the presence of neointimal hyperplasia was as high as 71% (interobserver comparison 62%). The mean difference for neointima area was 0.06 +/- 1.5 mm(2) (-0.6 +/- 1.5 mm(2)); mean differences for lumen area were 0.02 +/- 0.19 mm(2) (0.03 +/- 0.17 mm(2)) and for stent area 0.01 +/- 0.09 mm(2) (-0.02 +/- 0.12 mm(2)) (values for interobserver comparison are given in parentheses). Correlation between measurements was high for all structures: correlation coefficients were 0.66 (0.69) for neointima, 0.94 (0.95) for lumen, and 0.95 (0. 91) for stent area. CONCLUSIONS: Morphometric measurements of IVUS investigations with motorized IVUS pullback late after stent placement show good reproducibility. Intraobserver variability and interobserver variability are low. Differences for corresponding measurements were more pronounced for neointima area. Motorized catheter pullback guarantees high reliability of IVUS measurements and should be used routinely for clinical IVUS studies.

Aged↗

Predictors of reduced coronary flow reserve in heart transplant recipients without angiographically significant coronary artery disease.

BACKGROUND: Determination of coronary flow reserve (CFR) is increasingly used to assess the functional significance of cardiac allograft vasculopathy. Although the relation between CFR and angiographically defined vasculopathy has been studied extensively, little is known about other factors determining CFR in heart transplant recipients without significant lesions by coronary angiography. METHODS: Sixty consecutive patients were studied 0.5 to 148 months after heart transplantation with intracoronary Doppler and intravascular ultrasound. An endothelium-independent CFR< or =2.5 was defined as abnormal. Stepwise logistic regression analysis was used to identify factors (demographic data of donor and recipient, lipid profile, epicardial vessel morphology by intravascular ultrasound, left ventricular hypertrophy, acute rejection episodes, and hemodynamics) potentially associated with a reduced CFR. RESULTS: Only the presence of left ventricular hypertrophy (48% vs. 14%, P=0.007 and P=0.023, bivariate and multivariate analysis, respectively) and higher donor ages (41+/-12 vs. 29+/-11 years, P=0.002 and P=0.013, bivariate and multivariate analysis, respectively) showed an independent association with an abnormal flow reserve. CFR in patients with left ventricular hypertrophy was reduced due to higher baseline flow velocities (27+/-11 vs. 20+/-6 cm/sec, P=0.004). Furthermore, resting flow velocity increased as a function of donor age (r=0.264, P=0.047), while hyperemic flow velocity was not different. Other patient characteristics and hemodynamics did not affect CFR. CONCLUSION: The presence of left ventricular hypertrophy and higher donor ages independently contribute to a reduced CFR in patients after heart transplantation. This reduction in CFR is due to elevated baseline flow velocities rather than to a change in hyperemic flow velocities. These findings should be taken into account for the interpretation of reduced CFR values obtained by intracoronary Doppler in heart transplant recipients without angiographically overt coronary lesions.

Adult↗

Diagnostic and prognostic value of serial dobutamine stress echocardiography for noninvasive assessment of cardiac allograft vasculopathy: a comparison with coronary angiography and intravascular ultrasound.

BACKGROUND: Routine methods for surveillance of cardiac allograft vasculopathy (CAV) are coronary angiography and intravascular ultrasound (IVUS). This study analyzed the diagnostic and prognostic value of dobutamine stress echocardiography (DSE) for noninvasive assessment of CAV. METHODS AND RESULTS: In 109 heart transplant recipients, 333 DSEs were compared with 285 coronary angiograms and 199 IVUS analyses. Studies were repeated after 1, 2, 3, 4, and >/=5 years in 88, 74, 37, 18, and 7 patients, respectively. Resting 2D echocardiography detected CAV defined by IVUS and angiography with a sensitivity of 57% (specificity 88%). DSE increased the sensitivity to 72% (P=0.002). M-mode analysis increased the sensitivity of 2D rest and stress analysis (P=0.001, 0.004). Cardiac events occurred after 1.9% of normal stress tests by 2D analysis (combined 2D and M-mode: 0%), compared with 6.3% (3.8%) of normal resting studies. Worsening of serial DSE indicated an increased risk of events compared with no deterioration (relative risk 7.26, P=0.0014). Serial deterioration detected by stress only was associated with a higher risk of events than changes evident from resting studies (relative risk 3.06, P=0.0374). CONCLUSIONS: DSE identifies patients at risk for events and facilitates monitoring of CAV. A normal DSE predicts an uneventful clinical course and justifies postponement of invasive studies. The prognostic value of DSE is comparable to that of IVUS and angiography.

Adrenergic beta-Agonists↗

Quantitative changes in reference segments during IVUS-guided stent implantation: impact on the criteria for optimal stent expansion.

Intravascular ultrasound is an established method to optimize stent implantation. Stent expansion is estimated from the relation between minimal in-stent cross-sectional area and reference lumen area. We analyzed the periprocedural lumen increment in the reference segments and its impact on intravascular ultrasound (IVUS) criteria for optimized stenting. Seventy-five consecutive patients were studied with a 2.9 Fr, 30-MHz system and motorized pullback (0.5 mm/sec). Lumen area was measured by planimetry; absolute and relative differences in area (delta area) were calculated. Lumen area increment for reference segments proximal and distal to the stent was 6.4% +/- 10.3% and 6.1% +/- 10.8%; 49/75 patients fulfilled all IVUS criteria for optimal stent expansion at the final IVUS assessment, and 10/75 patients met all the IVUS criteria in relation to the first measurement of reference lumen area, but not in relation to the final measurement of reference lumen area. During high-pressure dilatation within the stent, reference lumen increment is visible. If reference lumen planimetry is not repeated after additional high-pressure balloon inflation, the final relative stent expansion may be overestimated.

Angioplasty, Balloon, Coronary↗

IVUS analysis of the acute and long-term stent result using motorized pullback: intraobserver and interobserver variability.

Intravascular ultrasound imaging has become an established method for analysis of intra-coronary stents. We analyzed the reproducibility of morphometric measurements immediately and late after stent implantation and the variability in the selection of predefined sites during motorized catheter pullback. Fifty consecutive patients were investigated immediately and 6 months after Palmaz-Schatz stent implantation (motorized catheter pullback 0.5 mm/sec; 2.9 Fr; 30-MHz transducer). Two experienced investigators independently identified the proximal and distal reference, stent inlet, stent outlet, and the minimal in-stent area in each imaging run. The longitudinal distance between corresponding measurement sites was calculated. Lumen, stent, and vessel area were assessed by planimetry, mean difference was calculated. Long-term reproducibility was analyzed by comparison of measurements made at predefined sites within the stent, immediately and late after implantation. Observer agreement in identification of predefined measurement sites was high. Longitudinal distance between corresponding measurement sites was low and pronounced for the minimal in-stent lumen area. Variabilities for the intra- and interobserver comparison were similar. Values for interobserver comparison were given in brackets. Acute after stent implantation, the variability for the reference proximal was 4.9% (0.4%), distal -1.0% (-4.2%), minimal in-stent lumen -0.5% (1.3%). At follow-up, variability for the reference proximal was -11.0% (-2.2%), distal -1.0% (-2.3%), minimal in-stent lumen 1.9% (6.1%). Long-term reproducibility for the proximal stent inlet was 2.7% (observer 1) and -0.4% (observer 2), for the distal stent outlet 1.3% (observer 1), -3.0% (observer 2), respectively. IVUS investigations with motorized IVUS pullback in stented coronary segments show a low intra- and interobserver variability, both immediately and late after stent implantation. Absolute and relative area differences are low. Long-term reproducibility of measurements within predefined stent sites was high. Motorized catheter pullback guarantees high reliability of IVUS measurements and should be routinely used for clinical IVUS studies.

Blood Vessel Prosthesis Implantation↗

[Acute hypopyon uveitis with rifabutin therapy of systemic Mycobacterium avium complex (MAC) infection in AIDS].

BACKGROUND: Hypopyon-uveitis has been identified as a dosage-dependent side effect in patients with acquired immunodeficiency syndrome who are treated for Mycobacterium avium complex (MAC) infection with systemic rifabutin. PATIENTS AND METHODS: We report a 38-year-old female AIDS patient with bilateral hypopyon uveitis under therapy with rifabutin in combination with clarithromycin and indinavir. RESULTS: At the time of presentation of the bilateral hypopyon uveitis the patient was treated with rifabutin (300 mg/day), clarithromycin (1000 mg/day) and ethambutol (1000 mg/day) for an M. avium complex infection. Also, the patient received the protease inhibitor indinavir. The rifabutin dose was reduced to 150 mg/day. Hypopyon and inflammation resolved under therapy with steroids. CONCLUSIONS: The concomitant use of rifabutin, clarithromycin, and protease inhibitors may lead to hypopyon uveitis. Reduction of dosage of rifabutin (150 mg/day) and treatment with topical steroids are required.

AIDS-Related Opportunistic Infections↗

[Secondary glaucoma in Paraguay. Etiology and incidence].

Glaucoma is the third-most-frequent cause of blindness in the world, with a total of 5.2 million blind people as a result of this disease; 80% live in developing countries. In Paraguay, after cataract it is the second-most-frequent-cause. Early detection of the risk factors and groups can help to avoid progress of this disease. Trauma, cataract and infectious uveitis represent special risks for developing secondary glaucoma, which is a more frequent cause of blindness in third-world countries than in industrialized nations. Until now there has been little data regarding the causes, disease course, and options for therapy. Therefore, secondary glaucoma was examined in Paraguay to obtain information on the situation in Latin America. The aim of the study was to explore the causes of secondary glaucoma for programs concerning prevention and therapy. From November 1996 to February 1997 patients with secondary glaucoma were examined at the University Hospital of Asunción, Paraguay. After the clinical examination the secondary glaucomas were classified. Patients with primary glaucoma were included in the same period of time as well in order to get the rate of secondary glaucoma. Altogether 293 patients were examined: 61 with secondary and 232 with primary glaucoma. The causes of secondary glaucoma in 73 eyes were: 20 (27%) with pseudoexfoliation glaucoma, 19 (26%) with post-traumatic glaucoma, 16 (22%) with neovascular glaucoma, 4 (5%) with lens-related glaucoma, 3 (4%) with glaucoma associated with ocular surgery, 2 (3%) with pigmentary and 2 (3%) with corticoid-induced glaucoma. A ratio of 4:1 primary glaucomas to secondary glaucomas was found. The development of special measures for prevention and early therapy is only possible if the causes of this severe disease are explored. The results of this study represent basic information and could help to introduce of prevention programs.

Adolescent↗

[Bacterial keratitis. Microbiological analysis as a principle for therapeutic recommendations].

PURPOSE: The study presented differentiates between the aetiological agents of bacterial keratitis in patients with and without a history of contact lens wear. Based on these results, recommendations are given for optimal antibiotic primary therapy. PATIENTS AND METHODS: Swabs and corneal scrapings were taken from 218 patients referred to the University Eye Hospital in Munich with a diagnosis of bacterial keratitis from 1989 to 1997. Ninety-two of these patients had a history of contact lens wear; 126 had none. The germs were isolated and identified by staining and microscopy. Observing polymicrobial growth in 51 patients, a total of 275 germs was isolated. RESULTS: The most frequent pathogens were Staphylococcus epidermidis (44%), S. aureus (18%), Streptococcus spp. (10%), Propionibacterium acnes (7%) and Pseudomonas aeruginosa (6%). Gram-negative germs were nearly exclusively isolated from contact lens wearers, gram-positive germs were predominant in non-contact lens wearers. CONCLUSION: Keratitis in patients with a history of contact lens wear is often caused by aggressive gram-negative germs. Those cases should immediately be treated with quinolones and erythromycin. In keratitis caused by gram-positive pathogens, a combination with aminoglycosides and erythromycin is sufficient.

Adolescent↗

[Preoperative infection prophylaxis with 1% polyvidon-iodine solution based on the example of conjunctival staphylococci].

BACKGROUND: Most germs causing postoperative endophthalmitis derive from the conjunctival bacterial normal flora. Postoperative endophthalmitis is often induced by staphylococcal germs. The application of polyvidone-iodine solution to the conjunctiva is one possibility to reduce potential endophthalmitis-causing bacteria. The aim of this study was to evaluate the effectiveness of 1% polyvidone-iodine solution concerning the reduction of colonization with staphylococci in the course of intraocular surgery. This is to evaluate the effectiveness of 1% polyvidone-iodine solution concerning coagulase-negative and positive staphylococci. PATIENTS AND METHODS: Patients with intrabulbar surgery (300) had three conjunctival swabs taken: the first immediately prior to preoperative preparation in the operating theatre, following in-patient application of antibiotic eye drops (Polymyxin-B-sulfat, Neomycinsulfat and Gramicidin in combination); the second swab was taken after antisepsis with polyvidone-iodine before opening the conjunctiva. At the end of surgery the third smear was taken. RESULTS: In 30.3% staphylococci were isolated from eyes before disinfection. Some patients (7.7%) were staphylococci-positive after disinfection; 5.3% of the patients showed staphylococcal growth at the end of surgery. To evaluate the effectiveness of polyvidone-iodine 1% solution we compared the first and the second smear (Mc Nemar). We found a statistically significant reduction (P < 0.001). At the end of surgery the conjunctival colonization with staphylococcal germs remained statistically significant reduced (P < 0.001). The mean operation time was 37 +/- 24 min. CONCLUSIONS: We concluded that a significant reduction of a staphylococcal colonization can be achieved by preoperative application of polyvidone-iodine (1%) (P < 0.001). Even at the end of surgery the effect of 1% polyvidone-iodine solution held.

Anti-Bacterial Agents↗

[Regression of cytomegalovirus retinitis in AIDS patients without systemic maintenance anti-cytomegalovirus therapy treated with highly active antiretroviral therapy].

BACKGROUND: The purpose of this study was to evaluate the course of CMV retinitis after initiation of highly active antiretroviral therapy (HAART) and discontinuation of systemic anti-CMV maintenance therapy. PATIENTS AND METHODS: Case reports are presented for two AIDS patients (2 eyes, ages 34, 43, male) with CMV retinitis. The CD4 count at the time of CMV retinitis was 20/microliter (patient 1) and 35/microliter (patient 2). Under HAART the CD4 count rose up to 202/microliter (patient 1) and 350/microliter (patient 2); the viral load was under detection limit in both patients. At that time systemic maintenance therapy was discontinued in both patients. RESULTS: There was no progression of retinitis during the observation period of 21 months (patient 1) and 24 months (patient 2). CONCLUSIONS: In selected patients with immune recovery under HAART it is possible to discontinue systemic anti-CMV maintenance therapy.

AIDS-Related Opportunistic Infections↗

Impact of target lesion calcification on coronary stent expansion after rotational atherectomy.

BACKGROUND: Calcified lesions carry the risk of suboptimal stent expansion. The purpose of this study was to investigate the impact of target lesion calcification on intracoronary ultrasound (ICUS) guided stent expansion after rotational atherectomy. METHODS: Stent expansion was assessed by ICUS in 39 patients with the aid of the proximal stent/proximal reference lumen, the minimal stent/mean reference lumen, and the minimal stent/minor reference lumen ratios as well as the symmetry index. Thirty-nine stent implantations in uncalcified lesions served for comparison. RESULTS: Relative stent expansion ranged between 76.3% +/- 6.7% and 98.4% +/- 16.4%. Categorization according to an ICUS-derived arc of superficial lesion calcium of <180 degrees (average 102 +/- 74 degrees) or >180 degrees (average 248 +/- 71 degrees) revealed decreased stent symmetry in calcified lesions >180 degrees compared with the control group (P <.05). Despite a trend toward less expansion with increasing calcium load, no significant differences of the lumen area ratios between the study groups was present. CONCLUSION: Rotational atherectomy before ICUS-guided stent implantation enables adequate stent expansion even in significant superficial target lesion calcification.

Aged↗

Functional and morphological findings in heart transplant recipients with a normal coronary angiogram: an analysis by dobutamine stress echocardiography, intracoronary Doppler and intravascular ultrasound.

BACKGROUND: Coronary angiography is still the routine screening method for cardiac allograft vasculopathy in most transplant centers. This study was designed to analyze functional and morphologic changes in heart transplant recipients with normal angiographic findings. METHODS: Dobutamine stress echocardiography and intracoronary ultrasound were obtained in 56 patients with a normal coronary angiogram 41+/-31 months after heart transplantation. Intracoronary Doppler flow velocity measurements before and after intracoronary adenosine administration were performed in 34 of 56 patients. Any regional wall motion abnormalities detected by stress echocardiography were regarded as abnormal. By quantitative intracoronary ultrasound analysis using a 6-grade scale, a mean grade of all coronary segments >3.0 was defined as significant intimal hyperplasia. RESULTS: Only 17 patients (30%) showed both a normal dobutamine stress echocardiogram and absence of significant intimal hyperplasia by intravascularultrasound. Abnormal findings were observed in 39 patients (70%): both by dobutamine stress echocardiography and intravascular ultrasound in 22 patients, by intravascular ultrasound alone in 11 patients, and by dobutamine stress echocardiography alone in 6 patients. Coronary flow velocity reserve did not discriminate between patients with normal or abnormal intravascular ultrasound or dobutamine stress echocardiographic findings. CONCLUSIONS: Only a minority of heart transplant patients with a normal coronary angiogram is free of pathological changes, when assessed by intravascular ultrasound and dobutamine stress echocardiography. Coronary flow velocity reserve does not seem useful to further characterize these patients.

Adenosine↗

Pressure-wire guided balloon angioplasty in allograft coronary vasculopathy.

We report a case of successful percutaneous transluminal coronary angioplasty guided from pressure-wire measurements in a transplanted patient. Fractional flow reserve, a lesion-specific, pressure-independent index of functional stenosis severity, was used to guide the intervention.

Angioplasty, Balloon, Coronary↗

[Bacterial keratitis in patients with and without contact lens anamnesis].

BACKGROUND: The study shows differences between contact lens wearers and patients without history of contact lenses regarding the spectrum of etiological agents in bacterial keratitis. Based on microbiological analysis, there are given recommendations for an optimal initial antibiotic treatment in both groups. MATERIAL AND METHODS: From 1989 to 1997 smears, scrapings and corneal biopsies were taken from 218 patients with bacterial keratitis. The causing pathogens were isolated on directly inoculated culture media and identified by staining and microscopy. The resistance pattern of a total of 275 germs was analysed for different antibiotics. RESULTS: The most frequently isolated germs were Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus spp., Propionibacterium acnes and Pseudomonas aeruginosa. Whereas sensitive gram-positive germs were predominating in contact lens wearers as well as in non-contact lens wearers, multiresistant gram-negative germs could nearly exclusively be isolated from contact lens wearers. Frequently administered antibiotics like aminoglycosides and quinolones are effective in infections caused by Staphylococcus spp., but increasing resistance could be seen to Streptococcus spp. In this case, erythromycin is very sensitive. Gram-negative germs like Pseudomonas aeruginosa are sensitive to quinolones and some aminoglycosides (e.g. tobramycin). CONCLUSION: In contact lens wearers, more aggressive germs have to be considered than in non-contact lens wearers. In such cases, frequently administered antibiotics like amino-glycosides are not effective. To cover problematic gram-negative germs we recommend the application of quinolones alternating with erythromycin. The latter one is more effective than quinolones and aminoglycosides in case of Streptococcus spp. co-involvement.

Adult↗

Removal of silicone oil with vision improvement after rhegmatogenous retinal detachment following CMV retinitis in patients with AIDS.

PURPOSE: To report that silicone oil may be safely removed from immuno-recovered patients with acquired immunodeficiency syndrome (AIDS) after instillation for cytomegalovirus (CMV)-related rhegmatogenous retinal detachment. METHOD: We report two patients with CMV-related retinal detachment who had previously been treated with vitrectomy and silicone oil. RESULTS: Six months after removal of silicone oil, the retina remained attached in both patients. Without specific anti-CMV therapy, there was no relapse of CMV retinitis while patients were undergoing highly active antiretroviral therapy. Best-corrected visual acuity improved in both patients. CONCLUSION: It appears to be possible to remove silicone oil safely from patients with AIDS who show immune recovery, thus avoiding side effects of long-standing silicone oil and increasing quality of life. After silicone oil removal, visual acuity was improved.

AIDS-Related Opportunistic Infections↗