Correlação dos níveis de NT-proBNP com CK-MB, troponina I, escore de risco timi e fração de ejeção do ventrículo esquerdo na síndrome coronariana aguda sem supradesnível do segmento ST

• Ano de defesa: 2006
• Autor(a) principal: Luiz Ricardo de Ataide Castro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Peptídeos natriurétricos; Síndrome coronariana aguda; Infarto agudo do miocárdio; Angina instável; Coronariopatias; Natriuréticos; Síndrome; Angina Instável; Infarto do miocárdio
• Link de acesso: http://hdl.handle.net/1843/ECJS-6XLHX8

Acute coronary syndrome without ST-segment elevation is definedby patients with unstable angina or non-ST elevation myocardial infarction and, when it is associated with the elevation of brain natriuretic peptide, it may lead to increased mortality rates. The human N-terminal pro-brain natriuretic peptide is produced in the heart, mainly in the ventricles, stimulated by myocyte stretch. Such process releases a biologically active 32 amino-acid molecule (brain natriuretic peptide) and the N-terminal fragment pro-brain natriuretic peptide comprising 76 amino acids. The present investigation is aimed to evaluate the meaning of the plasmatic dosage of the precursor of the N-terminal pro-brain natriuretic peptide in hospitalized patients with acute coronary syndrome without ST-segment elevation, unstable angina and non-ST elevation myocardial infarction and correlate with the markers of myocardium necrosis (creatine phosphokinase muscle-brain fraction and troponin I), with the TIMI risk score and with the left ventricular ejection fraction. The study was observational, transversal and descriptive, including 87 consecutive patients with definite diagnosis of acute coronary syndrome without ST-segment elevation. Exclusion criteria were: previous diagnosis or signs and symptoms of congestive heart failure; creatininelevels > 2.5 mg/dl; recent acute myocardial infarction and severe systemic arterial hypertension. The samples for the dosage of the N-terminal pro-brain natriuretic peptide were collected 72 hours after the beginning of the symptoms. The echocardiogram test was carried out in order to assess the left ventricular ejection fraction. The patients were divided into two groups: 37 (42.5%) with unstable angina; and 50 (57.5%) with non-ST elevation myocardial infarction. Left ventricular ejection fraction over 40% was found in 86.2% out of the total number of patients. Increased serum levels of the N-terminal pro-brain natriuretic peptideshowed to be more significant than those in patients with non-ST elevation myocardial infarction with unstable angina (p<0.001). Increased levels of Nterminal pro brain natriuretic peptide were associated with the increase in troponin I (rs=0.425, p<0.001), with the peak of creatine phosphokinase muscle-brain fraction (rs=0.458, p<0.001) and with the depression of the left ventricular ejection fraction (rs= 0.345, p=0.002), but was not correlated with the TIMI risk score (rs=0.082, p=0.44). Through multivariate analysis, the left ventricular ejection fraction (p=0.017), as well as the levels of troponin I (p=0.002) showed to beindependently correlated with the levels of the N-terminal pro-brain natriuretic peptide.