Sensitive Troponin I Assay in Patients with Chest Pain - Association with Significant Coronary Lesions with or Without Renal Failure / Troponinas I Sensíveis em Pacientes com Dor Torácica - Associação com Lesões Coronarianas Significativas e Variação em Insuficiência Renal Crônica

Abstract Introduction: Despite having higher sensitivity as compared to conventional troponins, sensitive troponins have lower specificity, mainly in patients with renal failure. Objective: Study aimed at assessing the sensitive troponin I levels in patients with chest pain, and relating them to the existence of significant coronary lesions. Methods: Retrospective, single-center, observational. This study included 991 patients divided into two groups: with (N = 681) and without (N = 310) significant coronary lesion. For posterior analysis, the patients were divided into two other groups: with (N = 184) and without (N = 807) chronic renal failure. The commercial ADVIA Centaur® TnI-Ultra assay (Siemens Healthcare Diagnostics) was used. The ROC curve analysis was performed to identify the sensitivity and specificity of the best cutoff point of troponin as a discriminator of the probability of significant coronary lesion. The associations were considered significant when p < 0.05. Results: The median age was 63 years, and 52% of the patients were of the male sex. The area under the ROC curve between the troponin levels and significant coronary lesions was 0.685 (95% CI: 0.65 - 0.72). In patients with or without renal failure, the areas under the ROC curve were 0.703 (95% CI: 0.66 - 0.74) and 0.608 (95% CI: 0.52 - 0.70), respectively. The best cutoff points to discriminate the presence of significant coronary lesion were: in the general population, 0.605 ng/dL (sensitivity, 63.4%; specificity, 67%); in patients without renal failure, 0.605 ng/dL (sensitivity, 62.7%; specificity, 71%); and in patients with chronic renal failure, 0.515 ng/dL (sensitivity, 80.6%; specificity, 42%). Conclusion: In patients with chest pain, sensitive troponin I showed a good correlation with significant coronary lesions when its level was greater than 0.605 ng/dL. In patients with chronic renal failure, a significant decrease in specificity was observed in the correlation of troponin levels and severe coronary lesions.

Resumo Fundamento: Apesar de apresentar maior sensibilidade em comparação às troponinas convencionais, as troponinas sensíveis apresentam menor especificidade, principalmente em pacientes com insuficiência renal. Objetivo: Avaliar os valores de troponina I sensível em pacientes com dor torácica, relacionando-os à presença de lesões coronarianas significativas. Métodos: Estudo retrospectivo, unicêntrico e observacional. Foram incluídos 991 pacientes, divididos em dois grupos: com (N = 681) ou sem lesão coronariana (N = 310). Para análise posterior, os pacientes foram separados em outros dois grupos: com (N = 184) ou sem insuficiência renal (N = 807). A troponina utilizada pertence ao kit comercial ADVIA Centaur® TnI-Ultra (Siemens Healthcare Diagnostics). A análise foi feita por curva ROC para identificar a sensibilidade e a especificidade do melhor ponto de corte da troponina como discriminador de probabilidade de lesão coronariana. As associações foram consideradas significativas quando p < 0,05. Resultados: Cerca de 52% dos pacientes eram do sexo masculino e a idade mediana da amostra foi de 63 anos. A área sob a curva ROC entre os valores de troponina e lesões coronarianas significativas foi de 0,685 (IC 95%: 0,65 - 0,72). Em pacientes sem e com insuficiência renal, as áreas sob a curva foram 0,703 (IC 95%: 0,66 - 0,74) e 0,608 (IC 95%: 0,52 - 0,70), respectivamente. Os melhores pontos de corte para discriminar a presença de lesão coronária significativa foram: 0,605 ng/dL (sensibilidade de 63,4%, especificidade de 67%) no grupo geral, 0,605 ng/dL (sensibilidade de 62,7% e especificidade de 71%) em pacientes sem insuficiência renal e 0,515 ng/dL (sensibilidade de 80,6% e especificidade de 42%) no grupo com insuficiência renal crônica. Conclusão: Na população avaliada de pacientes com dor torácica, a troponina I sensível apresentou boa correlação com lesões coronarianas significativas quando acima de 0,605 ng/dL. Em pacientes com insuficiência renal crônica, observamos uma queda importante de especificidade na correlação dos valores com lesões coronarianas graves.

Uso da cintilografia miocárdica em repouso durante dor torácica para descartar infarto agudo do miocárdio / Utilización de la centellografía miocárdica en reposo durante dolor torácico para descartar infarto agudo de miocardio / Use of resting myocardial scintigraphy during chest pain to exclude diagnosis of acute myocardial infarction

FUNDAMENTO: A imagem de perfusão miocárdica adquirida durante episódio de dor torácica tem sido utilizada nos pacientes na sala de emergência. OBJETIVO: Avaliar as características operacionais da cintilografia com 99mTc-Tetrofosmin durante episódio de dor torácica para descartar o diagnóstico de infarto agudo do miocárdio. MÉTODOS: 108 pacientes admitidos com dor torácica ou até quatro horas do término dos sintomas e eletrocardiograma não diagnostico realizaram cintilografia em repouso e dosagens de troponina I. Pacientes com passado de infarto do miocárdio (IM) não foram excluídos (24 pacientes). Troponina I foi dosada na admissão e seis horas após. Médicos nucleares realizaram análise cega das imagens. Infarto do miocárdio foi confirmado com elevação da troponina I maior que três vezes o controle. RESULTADOS: A imagem perfusional de repouso foi anormal em todos os seis pacientes com IM. Apenas um paciente apresentou imagem normal e elevação da troponina. Outros 55 pacientes obtiveram imagem positiva sem IM e 46 pacientes com imagens e troponinas normais. A prevalência da doença foi 6,5 por cento. A sensibilidade da imagem de repouso durante dor torácica para a evidência de IM foi 85,7 por cento e especificidade de 45,5 por cento. O valor preditivo negativo foi 97,7 por cento. CONCLUSÃO: Pacientes submetidos ao protocolo de dor torácica com cintilografia de perfusão miocárdica demonstraram um excelente valor preditivo negativo para afastar o diagnóstico de infarto do miocárdio. Estes resultados sugerem que a imagem de perfusão em repouso é uma ferramenta importante na unidade de dor torácica.

BACKGROUND: Images of myocardial perfusion taken during an episode of chest pain have been used for patients in the emergency department. OBJECTIVE: To evaluate the operating characteristics of 99mTc-Tetrofosmin scintigraphy during an episode of chest pain to exclude the diagnosis of acute myocardial infarction. METHODS: One hundred and eight patients admitted with chest pain, or up to four hours after the end of symptoms and nondiagnostic electrocardiogram, underwent resting scintigraphy and measurement of troponin I concentrations. Patients with a history of myocardial infarction (MI) were not excluded (24 patients). Troponin I concentrations were determined at admission and 6 hours later. Nuclear physicians performed a blind analysis of the images, and myocardial infarction was confirmed whenever troponin I level increase was three times that of the control. RESULTS: Resting perfusion image was abnormal in all 6 patients with MI. Only 1 patient had a normal image and increased troponin levels. Fifty-five patients had positive images without MI, and 46 patients had normal images and troponin levels. The prevalence of the disease was 6.5 percent. The sensitivity and specificity of the resting images during an episode of chest pain to diagnose MI was 85.7 percent and 45.5 percent, respectively. The negative predictive value was 97.7 percent. CONCLUSION: Patients undergoing chest pain protocol with SPECT showed an excellent negative predictive value to exclude diagnosis of myocardial infarction. These results suggest that resting perfusion image is an important tool at the chest pain unit.

FUNDAMENTO: La utilización en los pacientes de la imagen de perfusión miocárdica, adquirida durante episodio de dolor torácico, es frecuente en la sala de emergencia. OBJETIVO: Evaluar las características operacionales de la centellografía con 99mTc-Tetrofosmin, durante episodio de dolor torácico, para descartar el diagnóstico de infarto agudo de miocardio. MÉTODOS: Un total de 108 pacientes ingresados con dolor torácico, o hasta tras 4 horas del término de los síntomas, con electrocardiograma no diagnostico, realizaron centellografía en reposo y dosificaciones de troponina I. No se excluyeron a los pacientes con pasado de infarto de miocardio (IM) (24 pacientes). Se dosificó troponina I al ingreso y tras 6 horas del ingreso. Médicos nucleares realizaron análisis ciego de las imágenes. Se confirmó infarto de miocardio, con elevación de la troponina I mayor que tres veces el control. RESULTADOS: La imagen de perfusión en reposo se mostró anormal en todos los seis pacientes con IM. Sólo un paciente presentó imagen normal y elevación de la troponina. Otros 55 pacientes obtuvieron imagen positiva sin IM y 46 pacientes presentaron imágenes y troponinas normales. La prevalencia de la enfermedad fue de un 6,5 por ciento. Fue de un 85,7 por ciento la sensibilidad de la imagen de reposo durante dolor torácico para la evidencia de IM, y la especificidad de un 45,5 por ciento. El valor predictivo negativo fue de un 97,7 por ciento. CONCLUSIÓN: Pacientes sometidos al protocolo de dolor torácico con centellografía de perfusión miocárdica demostraron un excelente valor predictivo negativo para la exclusión del diagnóstico de infarto de miocardio. Estos resultados sugieren que la imagen de perfusión en reposo es una herramienta importante en la unidad de dolor torácico.

Predictores de síndrome coronario agudo sin supradesnivel del ST y estratificación de riesgo en la unidad de dolor torácico. Experiencia en 1.168 pacientes / Predictors of acute coronary syndrome without ST segment elevation and risk stratification in the chest pain unit

Background: Nearly 10 percent of patients with an actual acute coronary syndrome (ACS) are discharged with an inadequate diagnosis. Aim To select clinical and laboratory predictors to identify patients with a high likelihood of ACS in the Chest Pain Unit. Material and methods: Prospective evaluation of patients consulting in a Chest Pain Unit of a University Hospital. Initial assessment was standardized and included evaluation of pain characteristics, electrocardiogram and Troponin I. Independent predictors of ACS were identified with a multiple logistic regression. Results: In a four years period, 1,168 patients aged 62±23 years (69 percent males), were studied. After initial evaluation, 62 percent of the patients were admitted to the hospital for further testing and in 71 percent of them, a definite diagnosis of ACS was made. No events were reported by patients directly discharged from the Chest Pain Unit. Independent predictors associated with a higher likelihood of ACS were an abnormal electrocardiogram at the initial evaluation (Odds ratio (OR) 5.37, 95 percent confidence intervals (CI) 3.61-7.99), two or more cardiovascular risk factors (OR 2.16, 95 percent CI 1.21-2.84), cervical irradiation of the pain (OR 1.84, 95 percent CI 1.25-2.69), age over 65years (OR 1.73, 95 percent CI (1.32-2.27) and a Troponin I above the upper normal limit (OR: 5.68, 95 percent CI 3.72-8.29). Conclusions: Simple clinical findings allow an appropriate identification of patients with a high likelihood of ACS without specialized methods for myocardial ischemia detection.

An assessment of neutrophils/lymphocytes ratio in patients suspected of acute coronary syndrome / Avaliação da relação neutrófilos/linfócitos em pacientes com suspeita de síndrome coronariana aguda

FUNDAMENTO: A contagem total de leucócitos é um marcador de risco independente para eventos cardiovasculares. A relação entre a contagem de neutrófilos e linfócitos (N/L) tem sido explorada como novo preditor de risco cardiovascular, mas seu papel diagnóstico na avaliação de pacientes com suspeita de síndrome coronariana aguda (SCA) é desconhecido. OBJETIVO: Avaliar o valor diagnóstico da relação N/L em pacientes admitidos com suspeita de SCA em uma Unidade de Dor Torácica (UDT). MÉTODOS: Foram avaliados 178 pacientes admitidos com dor torácica, seguindo fluxograma diagnóstico conforme aspectos clínicos, eletrocardiográficos e laboratoriais. Os diagnósticos estabelecidos foram: infarto agudo do miocárdio com (IAMEST) e sem elevação de segmento ST (IAMSEST), angina instável (AI) e dor não-cardíaca (NC). Contagens total e diferencial de leucócitos foram realizadas em amostra de sangue periférico coletada na admissão. RESULTADOS: Pacientes com dor diagnosticada como não-cardíaca apresentaram a menor relação N/L (n = 45; 3,0 ± 1,6), seguidos por AI (n = 65; 3,6 + 2,9), IAMSEST (n = 33; 4,8 ± 3,7) e IAMEST (n = 35; 6,9 ± 5,7) (p < 0,0001). A relação N/L acima de 5,7 (quartil mais elevado) teve especificidade de 91,1 por cento, com odds ratio de 4,51 (intervalo de confiança de 95 por cento [IC 95 por cento], 1,51 a 13,45) para um diagnóstico final de SCA, em comparação com os grupos em quartis menores. CONCLUSÃO: A relação N/L apresenta correlação com o diagnóstico final de pacientes admitidos com suspeita de SCA. Por ser um exame de baixo custo e com boa reprodutibilidade, novos estudos deverão elucidar se a relação poderá ter importância nos fluxogramas diagnósticos atualmente empregados.

BACKGROUND: Leukocytes total count is an independent risk marker for cardiovascular events. The ratio between neutrophils and lymphocytes (N/L) count has been investigated as a new predictor for cardiovascular risk, although its diagnostic role when assessing patients suspected of an acute coronary syndrome (ACS) condition is not yet known. OBJECTIVE: To evaluate the diagnostic power of N/L ratio in patients who have been admitted at a Chest Pain Unit (CPU) with the suspicion of ACS. METHODS: Evaluation was conducted in 178 patients admitted with chest pain. Diagnostic flowchart including clinical, electrocardiographic, and laboratory data. Diagnosis obtained was: acute myocardial infarction (AMI) with (AMI-STE) and with no segment T elevation (AMI-NSTE), unstable angina (UA ) and non-cardiac pain (NC). Total and differential leukocyte count was conducted in peripheral blood sample collected at admission. RESULTS: Patients diagnosed with non-cardiac pain reported the lowest N/L ratio (n=45; 3.0 ± 1.6), followed by UA (n=65; 3.6 ± 2.9), AMI-NSTE (n=33; 4.8 ± 3.7) and AMI-STE (n=35; 6.9 ± 5.7); p < 0.0001. N/L ratio above 5.7 (highest quartile) reported 91.1 percent specificity, 4.51 odds ratio (CI 95 percent 1.51 to 13.45) for the final diagnosis of ACS when compared to the groups at lower quartiles. CONCLUSION: The N/L ratio presents correlation with final diagnosis of patients with suspicion of ACS at admission. Considering this is a low cost, good reproductibility test, new studies should ellucidate whether the ratio may be of relevance for diagnosis flowcharts currently in use.

Importância da proteína C-reativa no diagnóstico e no prognóstico intra-hospitalar em pacientes com dor torácica na sala de emergência / C-reactive protein diagnostic and prognostic value in patients presenting at the emergency room with chest pain / C-reactive protein diagnostic and prognostic value in patients presenting at the emergency room with chest pain

OBJETIVO: Testar os valores diagnóstico e prognóstico imediatos da proteína C-reativa (PCR) nos pacientes admitidos na sala de emergência (SE) com dor torácica (DT) e sem elevação do segmento ST no eletrocardiograma (ECG). MÉTODOS: De janeiro de 2002 a dezembro de 2003, 980 pacientes consecutivos foram atendidos com DT suspeita de síndrome coronariana aguda na SE (idade = 64,9 ± 14,3 anos, homens = 55 por cento, diabéticos = 18 por cento, ECG normal = 84 por cento). Dosou-se a PCR na admissão, a creatinofosfoquinase MB fração massa (CKMB) e a troponina I seriadas, além de se registrar ECG seriados. As medidas da PCR foram padronizadas (PCR-p) pelo valor do limite superior da normalidade (LSN) do teste utilizado (3,0 mg/L para a PCR de alta sensibilidade-PCR-AS e 0,1 mg/dl para PCR titulada-PCR-t). RESULTADOS: Foi diagnosticado infarto agudo do miocárdio (IAM) em 125 pacientes, e seus valores para a PCR-p foram 1,31 ± 2,90 (mediana = 0,47) versus 0,79 ± 1,39 (0,30) nos sem IAM (p = 0,031). A PCR-p > 1,0 apresentou sensibilidade de 30 por cento, especificidade de 80,4 por cento, valores preditivos positivo e negativo de 6,1 por cento e de 96,7 por cento, para o diagnóstico de IAM. Houve quarenta eventos cardíacos intra-hospitalares (óbitos = dezesseis, revascularizações de urgência = 22, IAM = dois). No 1° quartil da PCR-p (< 0,10) registraram-se três eventos, enquanto no 4° quartil (> 0,93) ocorreram quinze eventos (p = 0,003). Na regressão logística foram preditores independentes para eventos cardíacos a insuficiência ventricular esquerda, o sexo masculino e a PCR-p > 0,32, com razão de chances de 7,6, 2,8 e 2,2, respectivamente. CONCLUSÃO: Nos pacientes atendidos com DT na SE, a PCR-p: 1) Não foi um bom marcador de IAM, apesar de um valor normal praticamente afastar esse diagnóstico; 2) Um valor superior a um terço do seu limite superior da normalidade (LSN) (>1 mg/L da PCR-AS ou >0,33 mg/dl da PCR-t) foi preditor de eventos cardíacos adversos intra-hospitalares.

OBJECTIVE: To test immediate diagnostic and prognostic values of C-reactive protein (CRP) in patients admitted to the emergency room (ER) with chest pain (CP) without ST-segment elevation on the electrocardiogram (ECG). METHODS: From January 2002 to December 2003, 980 patients were consecutively seen in the ER with CP suggestive of acute coronary syndrome (ACS) (age = 64.9 ± 14.3, men = 55 percent, diabetic = 18 percent, normal ECG = 84 percent). Serial CRP, creatine kinase MB mass (CKMB-mass) and troponin I determinations were performed on admission, in addition to serial ECG. CRP measurements were standardized (s-CRP) by the upper limit of normal (ULN) of the test used (3.0 mg/L for high-sensitivity C-reactive protein [hs-CRP] and 0.1 mg/dL for titrated CRP [t-CRP]). RESULTS: One hundred and twenty-five patients were diagnosed with acute myocardial infarction (AMI), and their s-CRP values were 1.31 ± 2.90 (median = 0.47) compared to 0.79 ± 1.39 (0.30) in no-AMI patients (p = 0.031). The s-CRP > 1.0 showed 30 percent sensitivity and 80 percent specificity, plus negative and positive predictive values of 6.1 percent and 96.7 percent, respectively, for AMI diagnosis. There were forty in-hospital cardiac events (16 deaths, 22 urgent revascularizations, and 2 acute myocardial infarction). In the first quartile of the s-CRP (< 0.10), three events were recorded, while in the fourth quartile (> 0.93) 15 events (p = 0.003) occurred. In the logistic regression model, masculine gender and s-CRP > 0.32 (odds ratio 7.6, 2.8 and 2.2, respectively) were independent predictors of cardiac events and left ventricular failure. CONCLUSION: In patients with chest pain presenting at the emergency room, s-CRP was not a good marker of AMI, although this diagnosis is virtually excluded by a normal value; in addition, values one-third above the upper limit of normal (>1 mg/L for hs-CRP or >0.33 mg/dL for t-CRP) were predictive of in-hospital adverse cardiac events.

An Increased Monocyte Count Predicts Coronary Artery Spasm in Patients with Resting Chest Pain and Insignificant Coronary Artery Stenosis

BACKGROUND: Coronary atherosclerosis with inflammation gives rise to coronary vasospasm in the patients with coronary vasospastic angina. We have postulated that the peripheral leukocyte count and the differential count are associated with vasospastic angina. METHODS: 144 patients who underwent intracoronary ergonovine provocation testing between January 2002 and December 2004 were divided into two groups: Group I (72 patients with provoked spasm, mean age: 54.8+/-10.7 years, males: 75%) and Group II (72 without spasm, mean age: 55.3+/-10.2 years, males: 35%). Blood sampling was done to measure the lipid profiles and inflammatory markers, including the high sensitive C-reactive protein (hsCRP) levels and the monocyte counts. We compared the angiographic findings and laboratory data between the two groups. RESULTS: There were no significant differences in the levels of serum lipid and hsCRP between the two groups. The white blood cell count and the monocyte count were higher in Group I than with Group II (7496.4+/-2622.28 vs. 6703.2+/-1768.37/mm3, respectively, p=0.035; 627.5+/-270.70 vs. 426.9+/-205.76/mm3, respectively, p<0.001). Gensini's score was higher in Group I than in Group II (2.2+/-2.88 vs. 0.5+/-1.03, respectively, p<0.001). Multivariate analysis showed that the monocyte count and Gensini's score were independent factors affecting coronary spasm (p=0.047 and p=0.018, respectively). According to a receiver operating characteristics curve analysis, the area under the curve of the monocyte count was 0.738, that of the neutrophil count was 0.577 and that of the WBC count was 0.572. The cut-off value of the monocyte count was 530/mm3; the sensitivity and specificity of this cut-off value were 64% and 76%, respectively. CONCLUSIONS: The peripheral monocyte count is an independent marker for predicting vasospastic angina in the patients with resting chest pain and insignificant coronary artery stenosis.

Comparison in the measurements of myoglobin and troponins between cardiac reader and AxSYM system

The time factor is important in the diagnosis of myocardial infarction and therefore methods that help in diagnosis in a short time are preferable. This study was performed to compare the methods of detecting troponins and myoglobin in the blood, one, a bedside method and the other, a laboratory-based method. Forty-nine patients admitted to Rashid Hospital Coronary Care Unit, were studied. Thirty-five were confirmed to have acute myocardial infarction by the standard criteria of history, ST elevation in the ECG and rise of C.K.M.B. enzyme. The remaining l4 patients who were regarded as controls did not have acute myocardial infarction or acute coronary syndromes. Blood was taken from these patients up to 24 hours from the onset of chest pain and sent for analysis of myoglobin and troponin. From each patient, half of the blood specimens were analysed using CARDIAC reader [Boehringer Manheim [B.M.]] and the other half using AxSYM machine [Abbott]. In patients with acute myocardial infarction, both methods gave comparable and positive results. In the control group, both methods gave negative results. We conclude that both CARDIA C reader and AxSYM methods of assaying myoglobin and troponin are accurate and comparable in predicting patients with acute myocardial infarction