Valor prognóstico da troponina I de alta sensibilidade versus troponina T nas síndromes coronarianas agudas / Prognostic value of high-sensitivity troponin I versus troponin T in acute coronary syndromes

FUNDAMENTO: Apesar da superior precisão diagnóstica das troponinas cardíacas de alta sensibilidade, seu valor prognóstico ainda não foi validado contra troponinas cardíacas convencionais. OBJETIVO: Testar o valor prognóstico da troponina I de alta sensibilidade (TnI-as) em comparação com a troponina T convencional (TnT-c) no cenário de síndromes coronarianas agudas sem supradesnivelamento do segmento ST (SCA). MÉTODOS: No momento da admissão, uma amostra de plasma foi coletada de 103 pacientes consecutivos com angina instável ou infarto agudo do miocárdio sem supradesnivelamento do segmento ST. Nessa amostra, a troponina foi medida tanto pelo método TnI-as quanto pelo método TnT-c. O valor prognóstico das duas troponinas foi comparado em relação à ocorrência de evento cardiovascular maior, definido como o composto de morte, infarto agudo do miocárdio não fatal ou angina instável refratária durante a internação. RESULTADOS: Durante uma hospitalização mediana de 8 dias (intervalo interquartil = 5-11), a incidência de eventos cardiovasculares foi 10% (5 mortes, 3 infartos não fatais e 2 anginas refratárias não fatais). Troponina I de alta sensibilidade predisse significativamente eventos cardiovasculares, com C-estatísticas de 0,73 (95% CI = 0,59-0,87), à semelhança da TnT-c (0,70; 95% CI = 0,55-0,84) - P = 0,75. A definição de troponina positiva que proporcionou melhor acurácia prognóstica foi TnI-as > 0,055 mg / L e TnT-c > 0,010 mg / L, com sensibilidade de 90% e especificidade de 52% para ambos os ensaios. CONCLUSÃO: Troponina I de alta sensibilidade prediz eventos cardiovasculares de forma semelhante à troponina T convencional no cenário de SCA. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0).

BACKGROUND: Despite superior diagnostic accuracy of high-sensitivity cardiac troponins, their prognostic value has not been validated against conventional cardiac troponins. OBJECTIVE: To test the prognostic value of high-sensitivity cardiac troponin I (hs-cTnI), compared with conventional cardiac troponin T (cTnT) in the setting of non-ST elevation acute coronary syndromes. METHODS: At hospital admission, a plasma sample was collected from 103 consecutive patients with unstable angina or non-ST elevation acute myocardial infarction. In this sample, troponin was measured both by hs-cTnI and cTnT methods. Their prognostic value was compared as to the occurrence of major cardiovascular events, defined as a combination of death, nonfatal acute myocardial infarction or refractory unstable angina during hospitalization. RESULTS: During median hospitalization of 8 days (interquartile range = 5 - 11), the incidence of cardiovascular events was 10% (5 deaths, 3 non-fatal myocardial infarctions and 2 non-fatal refractory anginas). High-sensitivity troponin I significantly predicted cardiovascular events, with a C-statistics of 0.73 (95% CI = 0.59 - 0.87), similarly to cTnT (0.70; 95% CI = 0.55 - 0.84) - P = 0.75. The definition of positive cardiac marker that provided the best prognostic accuracy was hs-cTnI > 0.055 µg/L and cTnT > 0.010 µg/L, with equal sensitivity of 90% and specificity of 52% for both assays. Positive hs-cTnI was associated with 17% incidence of events, compared with 2% in patients with negative hs-cTnI (P = 0.02). CONCLUSION: High-sensitivity troponin I predicts cardiovascular events similarly to conventional troponin T in the setting of non-ST-elevation ACS. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0).

Prognostic value of high-sensitivity troponin I versus troponin T in acute coronary syndromes.

BACKGROUND: Despite superior diagnostic accuracy of high-sensitivity cardiac troponins, their prognostic value has not been validated against conventional cardiac troponins. OBJECTIVE: To test the prognostic value of high-sensitivity cardiac troponin I (hs-cTnI), compared with conventional cardiac troponin T (cTnT) in the setting of non-ST elevation acute coronary syndromes. METHODS: At hospital admission, a plasma sample was collected from 103 consecutive patients with unstable angina or non-ST elevation acute myocardial infarction. In this sample, troponin was measured both by hs-cTnI and cTnT methods. Their prognostic value was compared as to the occurrence of major cardiovascular events, defined as a combination of death, nonfatal acute myocardial infarction or refractory unstable angina during hospitalization. RESULTS: During median hospitalization of 8 days (interquartile range = 5 - 11), the incidence of cardiovascular events was 10% (5 deaths, 3 non-fatal myocardial infarctions and 2 non-fatal refractory anginas). High-sensitivity troponin I significantly predicted cardiovascular events, with a C-statistics of 0.73 (95% CI = 0.59 - 0.87), similarly to cTnT (0.70; 95% CI = 0.55 - 0.84) - P = 0.75. The definition of positive cardiac marker that provided the best prognostic accuracy was hs-cTnI > 0.055 µg/L and cTnT > 0.010 µg/L, with equal sensitivity of 90% and specificity of 52% for both assays. Positive hs-cTnI was associated with 17% incidence of events, compared with 2% in patients with negative hs-cTnI (P = 0.02). CONCLUSION: High-sensitivity troponin I predicts cardiovascular events similarly to conventional troponin T in the setting of non-ST-elevation ACS.

Avaliação da função e da lesão renal: um desafio laboratorial: [revisão] / Evaluation of renal function and damage: a laboratorial challenge: [review]

Atualmente a doença renal é um grande problema de saúde pública, que acomete milhares de pessoas no Brasil e no mundo. O estudo da função e dos diversos processos patológicos renais tem despertado o interesse de muitos pesquisadores, principalmente no campo do desenvolvimento de testes que auxiliem os médicos a estabelecer um diagnóstico precoce, classificar a doença de base, obter prognóstico seguro e monitorar terapêutica medicamentosa. Neste artigo sete marcadores de função e de lesão renal são avaliados: uréia, creatinina, cistatina C, proteinúria, dismorfismo eritrocitário, microalbuminúria e fração hepática das proteínas ligadas a ácidos graxos. É apresentado um breve histórico da utilização clínica e da fisiopatologia de cada um deles, seguidas de sua aplicabilidade e dos avanços técnicos e metodológicos disponíveis. Apesar de melhorias terem sido conseguidas e incorporadas à prática laboratorial, nenhum marcador atualmente disponível é completamente eficaz em analisar a função e/ou a lesão renal de forma precisa, sendo imprescindível o conhecimento de todos eles para uma correta avaliação desses testes comuns na rotina laboratorial.

Nowadays, renal disease is an important public health problem, affecting millions of people in Brazil and in the world. The study of renal function and renal pathologic processes has aroused the interest of researchers, mainly in the field of development of new assays that could aid physicians in establishing early diagnosis, better classifying the disease, obtaining better outcome and monitoring drug therapeutics. In this article, seven laboratory markers of renal function or damage are evaluated: urea, creatinine, cystatin C, proteinuria, dysmorphic erythrocytes, microalbuminuria and liver-type fatty acid binding protein (L-FABP). For each one of them, a short historical report of its clinical utility and physiopathology is presented. Then technical and methodological approaches are described as well as its utility in clinical management of kidney patients. Although improvements have been reached and incorporated in laboratorial practice, none of these markers is effective enough to define precisely kidney function and/or damage and an extensive understanding of all of these markers is crucial to correct evaluate renal function.

High-density lipoprotein subfractions in normolipidemic individuals without clinical atherosclerosis lipoprotein subfractions in an adult population.

This study evaluated the serum concentrations of lipids, lipoproteins, apolipoproteins, and high-density lipoprotein (HDL) subfractions in Brazilian adults. We analyzed the distribution of lipids in HDL2 and HDL3 in a normolipidemic population without evidence of established cardiovascular disease (CVD). A total of 93 males and 92 females, healthy and normolipidemic, volunteered to be submitted to a clinical examination, a blood collection, and to answer a questionnaire aimed at determining signs and symptoms of atherosclerotic disease. Their fasting plasma lipid, lipoproteins, apolipoproteins, and the cholesterol and triglyceride concentrations in HDL2 and HDL3, isolated by microultracentrifugation, were determined by enzymatic-colorimetric methods. The interpercentile intervals (2.5-97.5) for the population were established as being 5-18 mg/dL in men and 4-28 mg/dL in women for HDL2 cholesterol (HDL2chol) and 1-57 mg/dL in men and 2-61 mg/dL in women for HDL3 cholesterol (HDL3chol). HDL2 triglyceride levels (HDL2Tg) in men were 1-26 mg/dL and in women 2-28 mg/dL; moreover, the HDL3 triglyceride (HDL3Tg) intervals were established as 4-46 mg/dL for both sexes. The determination of reference ranges for lipids in HDL subfractions in populations without clinical atherosclerosis, is an useful tool for metabolic, diagnostic, and therapeutic approaches. We determined the intervals for HDL2chol, HDL3chol, HDL2Tg, and HDL3Tg. There were variations with sex and/or age for HDL2chol, HDL3chol, and HDL2Tg in the studied population.

The use of a hospital laboratory cohort to estimate the prevalence of dyslipidemia in an adult Brazilian population.

BACKGROUND: Dyslipidemia is diagnosed through the determination of plasma lipid profiles. This study is aimed at establishing the prevalence of dyslipidemia in a Brazilian out-patient population by using a hospital laboratory cohort. METHODS: Lipid profiles of 22,542 individuals from both sexes, aged 20 to 124 years, and registered at the University Hospital of the State University of Campinas, a standard of reference for hospital treatment in the state of São Paulo, Brazil, were retrospectively analyzed from 2000 to 2003. The cut-off values for cholesterol (C), triglycerides (TG), low-density lipoprotein-cholesterol (LDL-C) and high-density lipoprotein-cholesterol (HDL-C) were determined as recommended by the National Cholesterol Education Program. Statistical analyses were carried out using the SPSS program. RESULTS: Altered C, LDL-C and TG were found in 44%, 38% and 37% of adults and in 55%, 48% and 41% of the elderly, respectively; 35% of adults and 32% of the elderly presented undesirable low HDL-C. Combined dyslipidemia was very prevalent. CONCLUSION: Dyslipidemia was a serious public health problem in the studied population, especially among women and the elderly. The mixed phenotype of hypercholesterolemia and hypertriglyceridemia was the most prevalent. The results of this study were validated by their agreement with previously studied non-hospital Brazilian populations.