RESUMEN
OBJECTIVE: To evaluate systolic blood pressure (SBP) control in hypertensive patients with a stable coronary heart disease (CHD) in general practice in France. METHODS: A survey was conducted in a sample of 206 general practitionners (GP) representative of the French medical population, in 2003 [LHYCORNE survey]. Each GP had to include 3 hypertensive patients, >18 years old, BP > or = 140/90 mmHg and/or treated for hypertension, and with evidence of CHD documented by myocardial infarction (MI) or angina pectoris (AP) [diagnosis previously established by a cardiologist]. Three office BP measurements were performed, the last two recorded. BP levels were considered as controlled by treatement if they were < 140/90 mmHg. RESULTS: 595 patients were included, 75% men mean age 66 years, 25% women mean age 73 years. All patients had a CHD: MI 46%, AP 54%; 533 (90%) had more than 2 cardiovascular risk factors: hyperlipidemia (411; 69%), smokers (375; 63%), diabetes (158; 27%). Mean BP was 140.7 +/- 14/80.8 +/- 9.7 mmHg; 553 (93%) of these hypertensive patients were treated, and 239 (40%) were considered as having a controlled SBP at the treshold of 140 mmHg: 47% in patients with previous MI and 38% with AP (p < 0.001). Diastolic BP (DBP) was <90 mmHg in 480 (81%) and pulse pressure was >65 mmHg in 202 (34%); 313 (53%) patients received a combination of three drugs or more; 354 (60%) had a beta-blocker, 260 (44%) a calcium channel blocker, 237 (40%) an ACE inhibitor, 287 (48%) other antihypertensive drugs (246 diuretics, 41%); 502 (84%) received antiplatelet therapy, 403 (68%) statins. CONCLUSION: This survey shows that systolic BP is not at goal in 6/10 hypertensive patients with stable CHD suggesting there is a place for a more effective combination therapy according to evidence-based medicine.
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Antihipertensivos/uso terapéutico , Enfermedad Coronaria/complicaciones , Hipertensión/tratamiento farmacológico , Hipertensión/patología , Adulto , Anciano , Femenino , Francia , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
Allogeneic hematopoietic stem cell transplantation (SCT) is a widely used, cost-intensive procedure. Although pretransplant nonmyeloablative (NMA) or reduced-intensity conditioning regimens appear very promising, prospective studies comparing this approach with the conventional myeloablative (MA) approach in specific hematologic diseases are necessary, especially in patients in whom the conventional approach is not contraindicated. Cost may be an important factor in the decision-making process. We compared the costs of MA and NMA transplants in patients with acute myeloid leukemia (AML). We estimated 1-year resource utilization in 12 consecutive MA patients (median age: 39 years) and in 11 consecutive NMA patients (median age: 58 years) who underwent HLA-identical sibling SCT for AML. Resources care expenses were valued using the average daily rate for personnel costs, supplies, and room costs. Other data were directly collected from the patients' charts. Despite a trend for lower costs in NMA patients during the first 6 months, costs during the 6-12-month period were significantly higher after NMA due to late complications and readmissions (P=0.03). Finally, mean 1-year costs were not different in MA and NMA patients (P=0.75). Prospective studies comparing conventional and NMA approaches in homogeneous populations should include economic items.
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Trasplante de Células Madre Hematopoyéticas/economía , Leucemia Mieloide Aguda/terapia , Trasplante de Células Madre/métodos , Trasplante Homólogo/economía , Adulto , Anciano , Estudios de Cohortes , Femenino , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Enfermedad Veno-Oclusiva Hepática/etiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Recurrencia , Inducción de Remisión , Factores de Tiempo , Acondicionamiento Pretrasplante , Trasplante Homólogo/efectos adversosRESUMEN
BACKGROUND: Propionibacterium acnes, a gram positive, anaerobic, skin commensal bacillus, is too often considered a biologic fluid contaminant, of blood cultures in particular. Its implication has been shown in various infections, including brain abscess, ocular infections, osteitis, and acne. It is also the cause of infective endocarditis (IE). METHODS: Retrospective, observational study of 11 patients with P. acnes IE, hospitalised between 1993 and 2001 at the Louis Pradel Hospital, Lyon-Bron, and review of 20 published cases. RESULTS: P. acnes IE is rare, though its prevalence is probably underestimated. It is most likely to affect men (71%), and affects all ages (children 4/31 cases). An entry point, probably cutaneous, is rarely confirmed. P. acnes IE often develops on valve prosthesis (42%), and embolisms are common (61%). The infective site is usually aortic (55%). The often-subtle symptoms and slow growth of the organism in vitro complicate the diagnosis, which is often made at a late stage, when valvular and peri-valvular destruction has become major. Despite the high sensitivity of P. acnes to most antimicrobials, a surgical intervention is very often needed (81%). The mortality is relatively high (15% to 27%). Examination of pathologic specimens by polymerase chain reaction increases the sensitivity and speed of its detection. The identification of P. acnes in a biologic specimen, valvular tissue in particular, requires a thorough knowledge of the clinical context before concluding to contamination, and mandates close surveillance of the patient. P. acnes can be the cause of IE long before it has been detected.
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Endocarditis Bacteriana/diagnóstico , Infecciones por Bacterias Grampositivas/diagnóstico , Propionibacterium acnes , Anciano , Niño , Ecocardiografía Transesofágica , Endocarditis Bacteriana/microbiología , Endocarditis Bacteriana/mortalidad , Endocarditis Bacteriana/terapia , Femenino , Francia/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/mortalidad , Infecciones por Bacterias Grampositivas/terapia , Humanos , Lactante , Masculino , Persona de Mediana Edad , Prevalencia , Propionibacterium acnes/aislamiento & purificación , Estudios RetrospectivosRESUMEN
BACKGROUND: Following upon the recent development of minimally invasive coronary robotic surgery, we set out to evaluate the feasibility of bilateral internal mammary artery (IMA) harvesting using the voice-controlled AESOP 2000 video assisted robot. METHODS: The robot is placed on the right side of the patient. The left IMA is first totally video-harvested, with the arm of the robot crossing over the patient to reach the left chest. The voice-controlled movement of the arm allows the surgeon to obtain the best video image of the artery. After completion of the dissection, the arm is positioned on the right part of the chest. The right IMA is then harvested using the same technique. RESULTS: Two patients underwent harvest of a bilateral IMA using this technique. The time of dissection was 52 min and 86 min, respectively. CONCLUSION: This technique allows a more precise, faster, tremor-free dissection, as compared to a conventional thoracoscopic harvesting.
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Puente de Arteria Coronaria/métodos , Robótica/métodos , Arterias Torácicas/cirugía , Cirugía Torácica Asistida por Video/métodos , Adulto , Estudios de Factibilidad , Humanos , Anastomosis Interna Mamario-Coronaria/métodos , Arterias Mamarias/cirugía , Persona de Mediana Edad , Robótica/estadística & datos numéricos , Cirugía Torácica Asistida por Video/estadística & datos numéricos , Factores de TiempoRESUMEN
PURPOSE: The aim was to investigate in patients receiving doxorubicin whether any alteration in myocardial oxidative metabolism or blood flow as assessed by positron emission tomography (PET) could be observed either after the first dose of the drug, or during its chronic administration. METHODS: Six female non-heart-failure cancer patients treated with doxorubicin were included in a longitudinal study. Resting radionuclide cineangiography and PET scanning with carbon-11 acetate were performed the day before the initiation of doxorubicin treatment at a dosage of 50 mg/m2 every 3 weeks, and 3 weeks after the cumulative administration of 300 mg/m2 (chronic toxicity). In addition, PET was performed 24 h after the first administration of doxorubicin (evaluation of acute toxicity). Myocardial oxidative metabolism and blood flow were assessed by PET (acute and chronic toxicity), and left ventricular ejection fraction was measured by radionuclide angiography (chronic toxicity). RESULTS: Using PET for both acute and chronic toxicity evaluations, no significant effect of doxorubicin was observed either on the flux through the tricarboxylic acid (TCA) cycle or on myocardial blood flow. However, systolic left ventricular function showed a small but significant impairment after the administration of 300 mg/m2 of doxorubicin. CONCLUSIONS: Other hypotheses should be explored to better explain the predominant mechanisms of the cardiotoxicity of anthracyclines in humans.
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Antibióticos Antineoplásicos/efectos adversos , Circulación Coronaria/efectos de los fármacos , Doxorrubicina/efectos adversos , Corazón/efectos de los fármacos , Miocardio/metabolismo , Neoplasias/tratamiento farmacológico , Anciano , Ciclo del Ácido Cítrico/efectos de los fármacos , Electrocardiografía/efectos de los fármacos , Femenino , Humanos , Estudios Longitudinales , Persona de Mediana Edad , Neoplasias/metabolismo , Oxidación-Reducción , Tomografía Computarizada de EmisiónRESUMEN
The patients who have only single vessel disease of the right coronary artery have an excellent prognosis, unaffected by surgery. The object of this study was to evaluate the long-term prognosis of these patients after transluminal coronary angioplasty. The criteria of analysis were survival, anginal symptoms, quality of life and ergometric parameters. Two hundred and forty eight patients with an isolated lesion of the right coronary artery who underwent angioplasty were reassessed 39.6 +/- 22 months after angioplasty. The primary success rate was 89.9% with 5.2% of severe complications during the hospital period (myocardial infarction, bypass surgery, coronary angiography +/- angioplasty). The actuarial global and cardiac survival rates at 7 years were 88.4 and 96.2% respectively with no difference between the success and failure groups. The eight cardiovascular deaths and thirteen myocardial infarctions which were observed in the long-term were all in the successful angioplasty group. From the symptomatic viewpoint, 76% of the population became asymptomatic. The same results were observed in terms of quality of life with 58% of patients estimating it to be good in correlation with anginal status. The comparison of ergometric tests showed a significant gain in performance in 67% of patients. The authors conclude that the results suggest that angioplasty in single vessel disease of the right coronary artery provides a significant symptomatic and ergometric benefit but that it is impossible to assess the eventual benefits in terms of survival which would have needed a group of similar patients assessed under anti-ischaemic treatment and taking into consideration the recent innovations (stents, statins).
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Angioplastia Coronaria con Balón , Enfermedad Coronaria/terapia , Adulto , Anciano , Angina de Pecho/patología , Angina de Pecho/terapia , Enfermedad Coronaria/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Calidad de Vida , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Resultado del TratamientoAsunto(s)
Cateterismo Cardíaco/instrumentación , Angiografía Coronaria/instrumentación , Arterias Mamarias/diagnóstico por imagen , Diseño de Equipo , Análisis de Falla de Equipo , Humanos , Revascularización Miocárdica/instrumentación , Complicaciones Posoperatorias/diagnóstico por imagen , Sensibilidad y EspecificidadRESUMEN
OBJECTIVE: To evaluate and compare in a double-blinded and prospective study the incidence of adverse reactions between two contrast agents used for coronary angiography and ventriculography. The first agent was the non-ionic, dimeric, isotonic contrast medium iodixanol (Visipaque), the other was the ionic dimeric contrast medium ioxaglate (Hexabrix). METHODS: A total of 110 consecutive patients were randomized and received either iodixanol 320 mgl/ml or ioxaglate 320 mgl/ml. The efficacy, safety, tolerability and specific cardiovascular effects were evaluated. Adverse reactions were recorded during the procedure and during the first 24 hours after the examination. Hemodynamic and electrophysiological parameters were recorded before and after the ventricular injection and the first injections into the left and right coronary artery, respectively. RESULTS: The incidence of clinical adverse reactions was significantly different between iodixanol and ioxaglate (3% vs 28%, p = 0.0004). 24 patients (16 iodixanol; 8 ioxaglate) experienced no discomfort (sensation of warmth, coldness or pain), and the intensity of discomfort experienced by the remainder was similar for the two groups. No patient reported pain. During the 3 minutes after injection of contrast medium, the LV end-diastolic pressure increased but, apart from one reading, the increases with iodixanol were always significantly different (p < 0.05), and less than those for ioxaglate. During the same time period, heart rate was increased to a greater extent by ioxaglate (p < 0.05). QT interval was significantly (p < 0.05) prolonged with both ioxaglate and iodixanol, but the changes were less marked after iodixanol. The angiographic studies were of diagnostic quality for all patients and optimal diagnostic information was achieved in 92% of both groups. CONCLUSION: This randomized study shows that iodixanol and ioxaglate are of comparable diagnostic efficacy in coronary angiography and ventriculography, but that iodixanol is better tolerated by patients and results in less marked hemodynamic and eletrophysiological changes than does ioxaglate.
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Medios de Contraste/efectos adversos , Angiografía Coronaria/métodos , Ventrículos Cardíacos/diagnóstico por imagen , Ácido Yoxáglico/efectos adversos , Ácidos Triyodobenzoicos/efectos adversos , Adolescente , Adulto , Anciano , Método Doble Ciego , Erupciones por Medicamentos/etiología , Monitoreo de Drogas , Electrocardiografía/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Humanos , Laringitis/inducido químicamente , Persona de Mediana Edad , Náusea/inducido químicamente , Estudios ProspectivosRESUMEN
AIMS: To develop a predictive clinical risk score of post-operative morbidity after coronary artery bypass grafting. METHODS AND RESULTS: Data were collected retrospectively from 679 patients undergoing emergency or planned bypass surgery between 1 January and 31 December 1996. The incidence of morbidity was 23%. Multivariate stepwise logistic regression analysis on two-thirds of the patients identified eight independent risk factors for severe morbidity. Six of these were pre-operative: symptomatic right heart failure, previous ventricular arrhythmias, previous coronary bypass surgery, chronic pulmonary disease, ST changes on pre-operative electrocardiogram, body mass index <24 kg. m-2, and two were intra-operative factors: the surgeon who operated, and the cardiopulmonary bypass time. A predictive clinical risk score was developed with the six pre-operative risk factors. The negative predictive value of the model is 87% and the area under the receiver operating characteristic curve is 0.77. When tested on the remaining patients not used for developing the model, the area under the curve is 0.65. CONCLUSION: This pre-operative risk score provides a simple method of risk stratification for patients undergoing coronary artery surgery. However, as for all predictive models, the performance of the score decreases when applied to a population other than that used to develop it.
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Puente de Arteria Coronaria/efectos adversos , Adulto , Enfermedad Coronaria/cirugía , Femenino , Humanos , Modelos Logísticos , Masculino , Morbilidad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la EnfermedadRESUMEN
Intravascular ultrasound imaging is able to provide direct images of the stent meshwork. However, a paradoxical question remains unanswered: Why is it not possible to correct or prevent implantation defects by ultrasound-guided implantation? We postulate that these discrepancies are due to image artifacts. We performed an in vitro experiment allowing detection, physical characterization, and computerized simulations of the various aspects of these artifacts. The width of the echo of a strut is variable, dependent on its distance from the transducer. The stent strut echo orientation is variable, and depends on the position of the transducer inside the stent. The stent contour image depends on the position of the transducer. In conclusion, knowledge of these stent intravascular ultrasound image artifacts enabled us to discriminate accurately between artifacts and real stent implantation defects, and are indispensable for accurate qualitative and quantitative analyses of stents.
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Artefactos , Vasos Coronarios/diagnóstico por imagen , Stents , Ultrasonografía Intervencional , Arterias/diagnóstico por imagen , Simulación por Computador , Humanos , Procesamiento de Imagen Asistido por ComputadorRESUMEN
Intravascular ultrasound (IVUS) imaging enables detailed analysis and precise measurements of vascular cross-sections. However, to achieve a reduction in the existing level of observer variability requires the development of quantitative IVUS. We have developed a fully automatic intraluminal edge detection technique, based on adaptive active contour models and called ADDER (adaptive damping dependent on echographic regions) that allows the quantitation of the intraluminal cross-sectional area (ICSA). Using a 30-MHz mechanically rotated transducer mounted at the tip of a 3.5-F catheter, 58 normal and pathologic arterial segments (from coronary, renal, splenic, iliac, and carotid arteries) were imaged in vitro. These images were analyzed by 2 experts, E1 and E2, who manually traced the intraluminal contour twice for each image, as well as with ADDER. Intra-observer variabilities for ICSAs were found to be excellent (-1.454 +/- 3.51% for E1, 0.96 +/- 5.4% for E2). The inter-observer variability was 2.1 +/- 4.3%. The success factor for ADDER was 89%. Its intra-observer variability was null, as the method always finds a unique contour. The correlation between the automatically detected ICSA and the manual ICSA was: r = 0.99 (y = 1.03x + 0.89 mm2). Morphometric variations between manually and automatically traced contours, analyzed by the centerline method, were 100 +/- 140 mm on average. In conclusion, the ADDER automatic contour detection applied to IVUS images is robust and characterized by small systematic and random errors; therefore, quantitative IVUS is a useful tool in clinical research trials.
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Vasos Sanguíneos/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador/métodos , Humanos , Procesamiento de Imagen Asistido por Computador/instrumentación , UltrasonografíaAsunto(s)
Endocarditis Bacteriana , Antibacterianos/uso terapéutico , Profilaxis Antibiótica/métodos , Cateterismo Cardíaco , Ecocardiografía Doppler , Ecocardiografía Transesofágica , Endocarditis Bacteriana/clasificación , Endocarditis Bacteriana/diagnóstico , Endocarditis Bacteriana/epidemiología , Endocarditis Bacteriana/etiología , Endocarditis Bacteriana/fisiopatología , Endocarditis Bacteriana/terapia , Humanos , Incidencia , Selección de Paciente , Pronóstico , Factores de Riesgo , Resultado del TratamientoRESUMEN
Intravascular ultrasound enables detection of the components of atherosclerotic plaques. The diagnostic value was assessed by ROC (receiver operating characteristic) curves on images acquired in vitro and correlated with the histological findings in 61 arteries. Five questions were asked of each operator; the reply was represented by a continuous variable in order to express all nuances of judgement. The area under the ROC curve, Az, was the criterion of performance (0.5 : chance response : 1.0 : all replies were accurate). Detection of plaque was satisfactory (Az = 0.89). The three layer appearance of muscular arteries was well recognised (Az = 0.94). The fibrous composition of a plaque was only just satisfactory (Az = 0.88) with 38.7% interindividual variability. The lipid composition of the plaque was poorly recognised (Az = 0.76) with large interindividual variability (52.8%) : hypoechogenicity was too ambiguous a sign from the acoustic point of view. A hypoechogenic zone must not be synonymous with a lipid plaque but a cellular zone. Calcium can almost always be detected (Az = 0.98) with a very low interindividual variability (10.7%), fibrohyaline progression of some plaques can be confusing. The authors present a more objective description of endovascular ultrasonographic images. They conclude that the diagnostic performance of 30 MHz intravascular ultrasound is satisfactory but several limitations are apparent in the interpretation of images, especially hypoechogenic zone and hyper-reflective zones with high attenuation.
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Arteriosclerosis/diagnóstico , Curva ROC , Ultrasonografía Intervencional , Arterias/diagnóstico por imagen , Arterias/patología , Calcinosis/patología , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/patología , Fibrosis/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Técnicas In Vitro , Lípidos/análisis , Modelos Biológicos , Músculo Liso Vascular/patología , Variaciones Dependientes del Observador , Sensibilidad y Especificidad , Ultrasonografía Intervencional/métodosRESUMEN
A coronary angiographic view is said to be "optimal" when the directing radius of the X-ray beam is perpendicular to the long axis of a stenosis. The object was to fulfill two criteria: 1) the accurate calculation of the spatial orientation of the stenosis to obtain the optimal position, 2) rapid and optimal positioning of the angiographic material with easy rotation around the axis of the stenosis. Two combined solutions were proposed:the Advantx L/C (GE Medical systems) angiocardiographic system with three motorised axes of rotation and a specific software. This software takes into account two longitudinal axes of the stenosis traced by the operator in two conventional incidences and then determines the angles of optimal positioning (accuracy +/-5 degrees). During 97 consecutive coronary angiograms, the software was used in 23 cases (24%) and judged to be useful in 16 cases (70%). In 2 of the 23 cases (8%) the mechanical angles calculated could not be used, the incidences being incompatible with the patient's position. During the angiograms, the best two images of stenosis (one conventional, one optimal) were retained to form a pair of images. Eight observers analysed 37 pairs of images shown side by side. 65% of the images selected from each pair as being the best descriptive appearance of the stenosis came from the optimised system. During quantitative analysis, only the length of stenosis differed statistically between the two modes of acquisition (1.26 +/- 0.36 mm; p = 0.0014). This system is useful during coronary angiography for providing optimal views of stenosis free from any geometric distorsion and without superimposition of adjacent branches.
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Angiografía Coronaria/métodos , Intensificación de Imagen Radiográfica/métodos , Programas Informáticos , Angiografía Coronaria/instrumentación , Enfermedad Coronaria/clasificación , Enfermedad Coronaria/diagnóstico por imagen , Diseño de Equipo , Estudios de Evaluación como Asunto , Humanos , Modelos Estructurales , Intensificación de Imagen Radiográfica/instrumentación , Interpretación de Imagen Radiográfica Asistida por Computador , Sensibilidad y EspecificidadRESUMEN
RATIONALE AND OBJECTIVES: For determining the optimum angulations of the x-ray beam with respect to the vascular morphology of a given patient, the authors present a solution combining a single-plane angiographic system and a dedicated procedure. METHODS: The clinical evaluation of the vessel profiling acquisitions focuses on qualitative appraisal and quantitative analysis of conventional and optimum projections. RESULTS: The qualitative evaluation demonstrates the pitfall for an operator to discern optimum from conventional projections. The 70% of preferences for vessel profiling bear witness to the constraints imposed occasionally by the optimum angulations, which may be impracticable for various reasons. However, vessel profiling yields lesions inspection at an optimum view, free of geometric foreshortening. Moreover, there is less risk of superimposition with other branches. From a quantitative standpoint, vessel profiling unveils the lesion with a length significantly longer than in conventional view. CONCLUSIONS: Vessel profiling offers a qualitative optimization of angiographic images and more exact quantitative analysis.
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Angiografía Coronaria/métodos , Intensificación de Imagen Radiográfica/métodos , Angiocardiografía/métodos , Artefactos , Enfermedad Coronaria/diagnóstico por imagen , Vasos Coronarios/patología , Estudios de Evaluación como Asunto , Humanos , Procesamiento de Imagen Asistido por Computador , Fantasmas de Imagen , Programas Informáticos , Rayos XRESUMEN
To establish the diagnosis of alveolar hemorrhage (AH) in cells recovered by bronchoalveolar lavage (BAL), Golde and colleagues created a score based on the hemosiderin content of alveolar macrophages stained with Prussian blue. We used an easier method, calculating the percentage of siderophages among the total alveolar macrophages recovered by BAL. We have retrospectively studied this method in 240 BALs performed in 194 immunocompromised patients. Prussian blue staining was performed on each BAL sample, and the Golde score was calculated for 47 samples chosen at random. The methods were compared for diagnosing AH. The percentage of siderophages correlated well with the Golde score. AH was defined by at least 20% siderophages. This definition was validated by comparison with the method of Kahn and coworkers. AH was present in 87 (36%) of the samples and was significantly associated with four parameters: thrombocytopenia (< 50,000/mm3), other abnormal coagulation parameters, renal failure (creatinine > or = 2.5 mg/dl), and a history of heavy smoking. The diagnosis of AH did not correlate with either the cause or the outcome of pneumonia. AH was seen more frequently in cardiac transplant patients (75%). In our experience, (1) a percentage of siderophages > or = 20% is sufficient and is an easier determinant of the diagnosis of AH than the Golde score; and (2) AH is rarely the sole cause of lung injury and is usually associated with other causes of pneumonia. AH may be considered more as a sign than as a distinct disease in this population.
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Hemorragia/diagnóstico , Huésped Inmunocomprometido/inmunología , Enfermedades Pulmonares/diagnóstico , Adolescente , Adulto , Anciano , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Broncoscopía , Distribución de Chi-Cuadrado , Niño , Femenino , Hemorragia/epidemiología , Hemorragia/inmunología , Humanos , Incidencia , Enfermedades Pulmonares/epidemiología , Enfermedades Pulmonares/inmunología , Macrófagos Alveolares/citología , Macrófagos Alveolares/inmunología , Masculino , Persona de Mediana Edad , Neumonía/diagnóstico , Neumonía/epidemiología , Neumonía/inmunología , Pronóstico , Análisis de Regresión , Estudios RetrospectivosRESUMEN
Intravascular ultrasound catheters provide cross-sectional images of vessel walls and surrounding tissues with rotating transducers, and the behavior of ultrasound in heterogeneous media both cause degradation of image quality. Qualitative and quantitative analyses of in vivo studies are operator-dependent and limited by artifacts. We investigated these limitations by an in vitro study on plexiglass phantoms and segments of fresh arteries. We observed, analyzed and interpreted the most specific reasons for image artifacts: geometric distortions, the point spread function of the imaging system and the near field effects. Various practical implications have resulted from this study. Knowledge of the most obvious pitfalls will enable the user to obtain maximum benefits from intravascular ultrasound imaging, and to appreciate its limitations.
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Ultrasonografía Intervencional , Arteriopatías Oclusivas/diagnóstico por imagen , Arterias/diagnóstico por imagen , Artefactos , Interpretación Estadística de Datos , Humanos , Interpretación de Imagen Asistida por Computador , Reproducibilidad de los ResultadosRESUMEN
Intravascular ultrasound is a new method of visualizing details of vascular pathology, providing (real time) high resolution images of vascular walls. Most of the research on the technique has explored its qualitative and quantitative capabilities to improve the assessment of atherosclerotic vascular disease in vivo. Intravascular ultrasound differs from angiography and angioscopy in its ability to penetrate below the surface of the vessel lumen, demonstrating specific appearances of the distribution and composition of plaque. Image analysis is operator dependent. Although this technology is very promising limitations such as artefacts and loss of image quality in heavily calcified vessels hinder its use. There is hope that this imaging technique may ultimately improve the results of endovascular interventions.
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Arterias/diagnóstico por imagen , Arteriosclerosis/diagnóstico por imagen , Humanos , Técnicas In Vitro , UltrasonografíaRESUMEN
The ability of an intravascular ultrasound catheter to give cross-sectional images of vessel walls and surrounding tissues, and the behavior of ultrasound in heterogeneous media, are at the origin of degradation of image quality. Qualitative and quantitative analyses of in vivo studies are then operator-dependent and are limited by artifacts. We investigated these limitations by an in vitro study on plexiglass phantoms and segments of fresh arteries. We used a 20 MHz transducer mounted on the tip of a 4.8 F catheter and an interventional ultrasound system. The ultrasound beam is reflected onto the rotating transducer at 600 rotations per minute (RPM), creating 360 degrees real-time images (10 images/second). We then observed, analyzed and interpreted the most specific reasons for image artifacts: geometric distortions, multiple echoes, the point spread function (PSF) of the imaging system, near-field effects, "petal-shaped" effect, and ultrasound speckle. Various practical implications have resulted from this study. Only a thorough knowledge of how to avoid some of the most obvious pitfalls will enable the user to obtain maximum benefits from intravascular ultrasound imaging, and to appreciate its limitations.