Determinación cualitativa de marcadores de necrosis miocárdica desde la fase prehospitalaria del síndrome coronario agudo / Qualitative determination of markers for myocardiac necrosis during pre-hospital admission for acute coronary syndrome

Objetivo: medir el valor diagnóstico que tienen la troponina I, mioglobina y creatinfosfocinasa MB (CPK-MB) desde la fase de atención prehospitalaria, en pacientes con dolor torácico. Material y métodos: pacientes consecutivos que solicitaron atención prehospitalaria con ambulancia de terapia intensiva o que se encontraban en las primeras horas de hospitalización por dolor torácico. A todos se les realizó electrocardiograma de 12 derivaciones en la ambulancia o en el servicio de urgencias, y se les determinó nivel de creatinfosfocinasa sérica total (como patrón de referencia). Fueron distribuidos en cinco grupos: grupo I, 13 pacientes con infarto agudo del miocardio sin elevación del segmento ST; grupo II, 11 pacientes con angina inestable; grupo III, 14 pacientes con dolor torácico atípico para angina; grupo IV, cinco sujetos sanos; grupo V, cinco pacientes con infarto agudo del miocardio con elevación del segmento ST. Se hizo una evaluación cualitativa con un dispositivo automático de interpretación rápida para troponina I, mioglobina y CPK-MB. Resultados: 48 pacientes con edad promedio de 55 + 18 años: 25 hombres (52 %) y 23 mujeres (48 %). La mediana del tiempo de evolución de iniciados los síntomas fue de 3.5 horas (cuartiles 25, 75: 2 a 6). Para la troponina I, mioglobina y CPK-MB, la especificidad fue de 94, 91 y 94 %; la sensibilidad fue de 100 % para los tres marcadores, al igual que el valor predictivo negativo; el valor predictivo positivo fue de 89, 84 y 89 %, y el cociente de probabilidad de 8.7, 5.5 y 8.7, respectivamente. Conclusiones: desde la fase prehospitalaria, la troponina I, mioglobina y CPK-MB tienen alto valor diagnóstico en el síndrome coronario agudo. Su determinación es recomendable como parte del protocolo de diagnóstico y de gran ayuda para decidir la hospitalización y el tratamiento.

OBJECTIVE: We measured the diagnostic value of troponin I (TnI), mioglobin (Miog) and creatine kinase MB (CPK-MB) in patients with thoracic pain during the period of preadmission to the hospital. METHODS: We included patients who requested prehospital attention with intensive therapy ambulance or who were in the first hours of hospitalization for thoracic pain. A 12-lead electrocardiogram was carried out in the ambulance or in the emergency room. The levels of total creatine phosphokinase were determined (as reference pattern). Five study groups were included: group I, 13 patients with acute myocardial infarction without elevation of the ST segment; group II, 11 patients with unstable angina; group III, 14 patients with atypical thoracic pain for angina; group IV, five healthy patients; and group V, five patients with acute myocardial infarction with elevation of the ST segment. A qualitative evaluation was made with an automatic device for quick interpretation of TnI, Miog and CPK-MB. RESULTS: Forty eight patients were studied with an average age of 55+/-18 years, 25 men (52%) and 23 women (48%), average time of symptom evolution was 3.5 h (quartiles 2 and 6 h). Total level of CPK was taken as a reference pattern. Sensitivity of TnI, Miog, and CPK-MB was 100%, specificity was 94, 91 and 94%, respectively. Positive predictive value was 89, 84 and 89%, respectively. Negative predictive value was 100%. Likelihood of probability was 8.7, 5.5 and 8.7, respectively. CONCLUSIONS: TnI, Miog and CPK-MB have high diagnostic value in acute coronary syndrome (ACS) from the time of prehospital admission. Determination is advisable as part of the diagnostic protocol, which is of great importance in order to plan the hospitalization and treatment in this group of patients.

Preditores geométricos angiográficos de infarto do miocárdio não são associados com marcadores ultra-sonográficos de vulnerabilidade da placa / Angiographic geometric predictors of myocardial infarction are not associated with ultrasonographic markers of plaque vulnerability

OBJETIVO: Certas características geométricas angiográficas de lesões coronarianas foram descritas como preditoras independentes de um futuro infarto do miocárdio. O objetivo deste estudo foi correlacionar esses marcadores com achados do ultra-som intracoronariano sabidamente associados com maior vulnerabilidade à ruptura de placa. MÉTODOS: Estudou-se 30 pacientes com síndromes coronarianas estáveis e lesões de novo (31 lesões) com angiografia e ultra-som intracoronariano. Para cada lesão as características geométricas angiográficas (grau de simetria, grau de estenose, comprimento da lesão e ângulo de saída) foram correlacionadas com as variáveis ultra-sonográficas: tipo de placa (mole, fibrosa, mista ou calcificada), área porcentual de placa e índice de remodelamento. RESULTADOS: O comprimento médio da lesão foi de 9,2 ± 4,4 mm, o porcentual de estenose foi de 50,0 por cento a 89,0 por cento (média 67,7 ± 12,1 por cento), ângulos de entrada variaram de 8,48° a 48,78° (média 24,0 ± 11,4°), ângulos de saída variaram de 8,30° a 53,03° (média 23,8 ± 11,7°) e o índice de simetria variou de 0 a 1 (média 0,56 ± 0,32). A avaliação com ultra-som intracoronariano, freqüência de placas moles ou calcificadas, remodelamento positivo e magnitude da área porcentual de placa não foram associados com nenhuma característica geométrica angiográfica (p > 0,05 para todas as análises). CONCLUSÃO: Características geométricas angiográficas que predis-põem à oclusão aguda não se correlacionam com achados morfológicos e quantitativos do ultra-som intracoronariano associados com a vulnerabilidade da placa.

Early experience with percutaneous transluminal coronary angioplasty in unstable angina.

Percutaneous transluminal coronary angioplasty was done in 13 of 105 patients with unstable angina, 10 of whom were males. Diagnostic coronary angiography revealed single vessel disease in 10 cases and two vessel disease in 3 cases; the degree of stenosis varied from 70-90%. Only a single major coronary artery was dilated. Immediate angiographic success was achieved in 12(92.3%) cases. The success rate at the time of discharge from hospital was 10 (76.9%) cases. Immediate complications encountered were acute myocardial infarction in 2 cases, they refused coronary artery bypass grafting and unsuccessful dilation in 1 case. No death occurred during the hospital stay. During follow-up of 6-9 months, 8 patients were symptom free (66.6%), 2 patients required repeat percutaneous transluminal coronary angioplasty and 2 patients died. In conclusion, percutaneous transluminal coronary angioplasty may be undertaken relatively safely in unstable angina, it leads to substantial improvement in symptoms during the early follow-up period. This therapeutic approach is highly beneficial particularly in single vessel disease.

Morphometric analysis of coronary lesions in patients with unstable angina--an arteriographic study.

In 100 patients with unstable angina and 50 patients with stable angina qualitative morphology of coronary artery lesions were compared by angiography. The mean age of the patients was 51 years. In the unstable angina group, 50 patients had rest angina, 32 had crescendo angina and 18 had denovo angina; 31 patients had single vessel disease, 33 had two vessel disease, 34 had triple vessel disease and 2 had left main disease. 'Angina-producing' artery could be identified in 90 out of 100 patients. Ten totally occluded vessels were excluded from analysis. Lesions causing diameter stenosis of greater than 50% could be categorised to one of the following groups: a) Concentric stenosis (18 vessels), b) Type I eccentric lesion (asymmetric narrowing with smooth borders and broad neck--20 vessels), c) Type II eccentric lesion (asymmetric narrowing with narrow neck and overhanging irregular edges--47 vessels), and d) Multiple irregularities (15 vessels). Lesions in 9 vessels showed an associated thrombus. It appears that Type II eccentric lesions are frequent in patients with unstable angina; they probably represent ruptured atherosclerotic plaque or partially occlusive thrombi or both.