Sensibilidade e especificidade do hormônio natriurético do tipo B para identificar doentes com insuficiência mitral grave sintomáticos e assintomáticos

Abstract

ObjectiveTo assess the sensitivity and specificity of B-type natriuretic peptide (BNP) for identifying symptomatic and asymptomatic patients with severe chronic mitral regurgitation followed up on an outpatient care basis. Methods A group of patients with mitral regurgitation underwent electrocardiography, chest teleradiography, venous blood withdrawal, and transthoracic echocardiography. Based on an analysis of the echocardiographic variables, 62 patients had mild and moderate mitral regurgitation (GI) and 34 had severe mitral regurgitation (GII). The discriminating capacity of the BNP for detecting patients with severe mitral regurgitation was assessed by use of ROC curves. ResultsThe patients' ages ranged from 15 to 63 (mean, 31.7) ConclusionThe BNP values capable of identifying asymptomatic and symptomatic patients with severe mitral regurgitation are lower than 100 pg/mL, which is considered for the diagnosis of heart failure. Key words mitral regurgitation, natriuretic peptides, BNPThe measurement of B-type natriuretic peptide (or brain natriuretic peptide, BNP) levels has been used for diagnosing congestive heart failure, especially when the symptoms and signs are discrete or mild, and in the presence of associated comorbidities, such as pulmonary disease or obesity 1 . The BNP levels have a positive correlation with left ventricular end-diastolic pressure and an inverse correlation with left ventricular function. These concentrations are considered to represent an independent evaluation of ventricular function, with no need for other more expensive tests 2 . The cutoff point of the BNP levels recommended for separating the population with heart failure from that without that syndrome is 100 pg/mL 3 . These initial findings suggest the possibility of expanding the application of BNP level measurement to other situations that gradually lead to left ventricular dysfunction, such as some valvular diseases and congenital heart diseases. The BNP levels in patients with mitral regurgitation are greater than those in controls. The study by Brookes et al 4 showed that 89% of the 22 patients with mitral regurgitation have more elevated BNP levels than healthy individuals do, 20.85 ± 16.9 versus 3.37 ± 0.9 pmol/L. Another study 5 with symptomatic and asymptomatic patients showed that the BNP levels increased according to the severity of mitral regurgitation and were greater in symptomatic patients. However, the case series of these reports are small, and the authors of both studies suggested additional investigation. The objective of the present study was to assess in a group of patients with chronic mitral regurgitation of different degrees, which is the BNP cutoff point capable of identifying the existence of severe mitral regurgitation with or without symptoms. MethodsThe study comprised patients from the valvular heart disease outpatient clinic of our institution diagnosed with chronic mitral regurgitation and who agreed to participate in the study. The diagnosis was based on physical examination due to the ...

Clinical and functional characterisation of rheumatic mitral regurgitation in children and adolescents including the brain natriuretic peptide

“…Earlier studies carried out on adults have shown a correlation between brain natriuretic peptide and the functional class of mitral regurgitation, with a progressive increase in the hormone levels accompanying an increase in functional class. 14,[32][33][34] This contrasts with the results of this study. A serious rise in brain natriuretic peptide occurs most commonly in patients with functional class III, but the median was just a little higher and not statistically significant.…”

“…Enriquez-Sarano et al 4 demonstrated that functional class has a predictive value of early or late mortality in mitral regurgitation, such that awaiting symptoms for the indication of surgery were associated with a significant rise in postoperative mortality. Earlier studies carried out on adults have shown a correlation between brain natriuretic peptide and the functional class of mitral regurgitation, with a progressive increase in the hormone levels accompanying an increase in functional class 14 , 32 – 34 . This contrasts with the results of this study.…”