Arquivos Brasileiros de Cardiologia (Feb 2005)
Determinação do peptídeo natriurético cerebral humano em portadores da doença de Chagas Measurement of human brain natriuretic peptide in patients with Chagas' disease
Abstract
OBJETIVO: Determinar os níveis séricos do peptídeo natriurético cerebral (PNB) em pacientes com cardiopatia chagásica crônica e em indivíduos com sorologia positiva para doença de Chagas sem comprometimento cardíaco, e correlacionar os níveis de PNB com o grau de comprometimento cardíaco, dimensões cardíacas, presença de marcapasso e fração de ejeção. MÉTODOS: Concentrações séricas de PNB foram determinadas através do Triage® - BNP Test, produzido pela BIOSITE®. Foi avaliado o PNB sérico de 25 indivíduos do ambulatório de doença de Chagas do Hospital Universitário Oswaldo Cruz, distribuídos em 2 grupos, um, G1; composto por 13 portadores de sorologia positiva para doença de Chagas, assintomáticos e sem cardiopatia detectável pelo eletrocardiograma, radiografia do tórax e ecocardiograma, o outro, G2; por 12 portadores da doença de Chagas com comprometimento cardíaco. RESULTADOS: Níveis significativamente mais elevados de PNB foram detectados nos pacientes chagásicos com comprometimento cardíaco: (G1=4,4±4,4 pg/ml, G2=293,0±460,2 pg/ml) pOBJECTIVE: To measure the serum levels of brain natriuretic peptide (BNP) in patients with chronic chagasic heart disease and in individuals with positive serology for Chagas' disease and no heart impairment, and to correlate the serum BNP levels with the degree of cardiac impairment, cardiac dimensions, presence of a pacemaker, and ejection fraction. METHODS: Serum BNP concentrations were determined by use of the Triage - BNP Test produced by BIOSITE. Serum BNP was assessed in 25 patients from the Chagas' disease outpatient clinic of the Hospital Universitário Oswaldo Cruz, who were divided into 2 groups as follows: 1) G1 - comprising 13 assymptomatic patients with positive serology for Chagas' disease and no heart disease detectable on electrocardiography, chest X-ray, and echocardiography; and 2) G2 - comprising 12 patients with Chagas' disease and heart impairment. RESULTS: Significantly more elevated BNP levels were detected in the chagasic patients with cardiac impairment: (G1=4.4 ±4.4 pg/ml, G2=293.0±460.2 pg/ml); (P<0.01). In the 2 groups, the serum levels of BNP correlated neither with age nor with sex. The levels were directly proportional to functional class and cardiac area on chest X-ray. Although a trend towards an increment in systolic function impairment was observed, no linear correlation with the ejection fraction on echocardiography occurred. The presence of definitive pacemaker and electrocardiographic alterations did not change the serum BNP levels. CONCLUSION: Asymptomatic individuals with a positive serology for Chagas' disease and no evidence of ventricular dysfunction have serum BNP levels similar to those of the general population.
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