ABSTRACT
FUNDAMENTO: O diagnóstico de Embolia Pulmonar (EP) ainda requer longos períodos de trabalho e inúmeros testes. OBJETIVO: Nosso objetivo é avaliar os desfechos clínicos após uma investigação negativa usando um protocolo combinado de angio TC de tórax e venografia por TC (CTA/CTV) como único teste de diagnóstico em pacientes não selecionados com suspeita de EP. MÉTODOS: Estudo de coorte retrospectivo que incluiu pacientes consecutivos com suspeita de EP que foram investigados com um protocolo combinado de CTA/CTV. Os pacientes que apresentaram inicialmente uma investigação negativa e não receberam anticoagulantes foram acompanhados por seis meses para ocorrência de eventos tromboembólicos venosos recorrentes. RESULTADOS: De 425 pacientes com suspeita de EP, 62 (14,6%) tiveram diagnóstico de tromboembolismo venoso no CTA/CTV inicial. A média de idades foi de 56 ± 19 anos, e 61% da população se enquadravam na categoria de baixa probabilidade clínica. A trombose venosa profunda isolada representou 21% de todos os eventos tromboembólicos venosos, e quando se considerou toda a população, a CTV foi associada a um incremento no rendimento diagnóstico de 3,1%. Nosso grupo era composto de 320 pacientes com CTA/CTV inicialmente negativo e que não receberam anticoagulantes. Após seis meses de acompanhamento, apenas três pacientes apresentaram recorrência de eventos tromboembólicos (0,9%, IC 95% -0,1% - 2,0%) e nenhum foi fatal. Não houve mortes relacionadas com a EP. CONCLUSÕES: Nosso estudo sugere que uma estratégia de diagnóstico que utiliza CTA/CTV como único teste de diagnóstico pode descartar EP com segurança, em população com risco baixo a moderado, e está associada a resultados favoráveis, com um valor preditivo negativo de 99,1%. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0).
BACKGROUND: The diagnosis of pulmonary embolism (PE) still requires long work-up periods and multiple tests. OBJECTIVE: We aim to assess clinical outcomes after a negative investigation using a combined protocol of CT pulmonary angiography and CT venography (CTA/CTV) as a sole diagnostic test in unselected patients with suspected PE. METHODS: This retrospective cohort study enrolled consecutive patients with suspected PE who were investigated with a combined CTA/CTV protocol. Patients who had an initially negative investigation and were not anticoagulated were followed for 6 months for the occurrence of recurrent venous thromboembolic events. RESULTS: Out of 425 patients with suspected PE, 62 (14.6%) had venous thromboembolism diagnosed on the initial CTA/CTV. The mean age was 56 ± 19 years and 61% of the population fell into the low clinical probability category. Isolated deep vein thrombosis represented 21% of all venous thromboembolic events, and when considering the whole population, CTV was associated with an increment in diagnostic yield of 3.1%. Our cohort was composed of 320 patients with initially negative CTA/CTVs and who were not anticoagulated. After 6 months of follow up, only three patients presented with recurrent thromboembolic events (0.9%; 95% CI -0.1% - 2.0%) and none was fatal. There were no PE-related deaths. CONCLUSION: Our study suggests that a diagnostic strategy that utilizes CTA/CTV as a sole diagnostic test can safely rule out PE in a low to moderate risk population and is associated with favorable outcomes with a negative predictive value of 99.1%. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0).
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Angiography/methods , Pulmonary Embolism , Tomography, X-Ray Computed/methods , Cause of Death , Clinical Protocols , Cohort Studies , Lung , Outcome Assessment, Health Care , Phlebography/methods , Risk Factors , Radiography, Thoracic/methods , Tomography Scanners, X-Ray Computed , Venous ThromboembolismABSTRACT
BACKGROUND: The diagnosis of pulmonary embolism (PE) still requires long work-up periods and multiple tests. OBJECTIVE: We aim to assess clinical outcomes after a negative investigation using a combined protocol of CT pulmonary angiography and CT venography (CTA/CTV) as a sole diagnostic test in unselected patients with suspected PE. METHODS: This retrospective cohort study enrolled consecutive patients with suspected PE who were investigated with a combined CTA/CTV protocol. Patients who had an initially negative investigation and were not anticoagulated were followed for 6 months for the occurrence of recurrent venous thromboembolic events. RESULTS: Out of 425 patients with suspected PE, 62 (14.6%) had venous thromboembolism diagnosed on the initial CTA/CTV. The mean age was 56 ± 19 years and 61% of the population fell into the low clinical probability category. Isolated deep vein thrombosis represented 21% of all venous thromboembolic events, and when considering the whole population, CTV was associated with an increment in diagnostic yield of 3.1%. Our cohort was composed of 320 patients with initially negative CTA/CTVs and who were not anticoagulated. After 6 months of follow up, only three patients presented with recurrent thromboembolic events (0.9%; 95% CI -0.1% - 2.0%) and none was fatal. There were no PE-related deaths. CONCLUSION: Our study suggests that a diagnostic strategy that utilizes CTA/CTV as a sole diagnostic test can safely rule out PE in a low to moderate risk population and is associated with favorable outcomes with a negative predictive value of 99.1%.
Subject(s)
Angiography/methods , Pulmonary Embolism/diagnostic imaging , Tomography, X-Ray Computed/methods , Adult , Aged , Cause of Death , Clinical Protocols , Cohort Studies , Female , Humans , Lung/diagnostic imaging , Male , Middle Aged , Outcome Assessment, Health Care , Phlebography/methods , Radiography, Thoracic/methods , Risk Factors , Tomography Scanners, X-Ray Computed , Venous Thromboembolism/diagnostic imagingABSTRACT
Many parasite populations are difficult to sample because they are not uniformly distributed between several host species and are often not easily collected from the living host, thereby limiting sample size and possibly distorting the representation of the population. For the parasite Schistosoma mansoni, we investigated the use of eggs, in aggregate, from the stools of infected individuals as a simple and representative sample. Previously, we demonstrated that microsatellite allele frequencies can be accurately estimated from pooled DNA of cloned S. mansoni adults. Here, we show that genotyping of parasite populations from reproductively isolated laboratory strains can be used to identify these specific populations based on characteristic patterns of allele frequencies, as observed by polyacrylamide gel electrophoresis and automated sequencer analysis of fluorescently labeled PCR products. Microsatellites used to genotype aggregates of eggs collected from stools of infected individuals produced results consistent with the geographic distribution of the samples. Preferential amplification of smaller alleles, and stutter PCR products, had negligible effect on measurement of genetic differentiation. Direct analysis of total stool eggs can be an important approach to questions of population genetics for this parasite by increasing the sample size to thousands per infected individual and by reducing bias.