ABC | Volume 110, Nº3, March 2018

Original Article Almeida Junior et al BNP, echo and clinical evaluation in heart failure Arq Bras Cardiol. 2018; 110(3):270-277 Methods Sample studied A prospective convenience sample of patients admitted to the emergency department or coronary care unit of three hospitals (one university-affiliated and two tertiary hospitals) due to ADHF was studied. The study was conducted according to the Declaration of Helsinki standards for human research. Institutional review boards approved the research protocol, and all participants provided written informed consent before enrollment. Inclusion criteria Patients with ADHF due to LV systolic dysfunction, with LV ejection fraction (LVEF) <40% by Simpson's method, New York Heart Association (NYHA) functional class III or IV on admission and sinus rhythm were included within 24 hours of emergency care. Exclusion criteria The exclusion criteria were as follows: ADHF due to acute coronary syndrome; echocardiographic window precluding adequate analysis of hemodynamic parameters; primary valve disease; mechanical prosthetic valve; single mitral flow pattern; and presence of cardiac pacing. Physical examination The following physical findings were evaluated: jugular venous distension; hepatojugular reflux; hepatomegaly; ascites; lower extremity edema; third heart sound (S3); pulmonary rales; arterial blood pressure; and proportional pulse pressure. Patients were examined in a quiet emergency or critical care room. The jugular venous distension was evaluated with the patient sitting upright and the presence of a visible internal jugular vein above the clavicle was considered elevated. The hepatojugular reflux was tested in patients with no visible jugular vein, applying a firm right abdominal pressure. The liver was examined with the patient in recumbent position. Hepatomegaly was considered when the liver had more than 10cm of length, considering percussion technique initiating on the third intercostal space, along the midclavicular line. Liver palpation was the method of choice to assess the lower margin of the liver if it was palpable in the abdomen. Patients with chest radiography showing any sign of congestion were considered to be congested. The radiological evaluation was done through the posterior-anterior and left lateral chest radiography. In cases of inability to take chest radiography in posterior-anterior and lateral positions, an anterior-posterior position with the patient sitting in bed was performed. The chest radiography was performed immediately prior to the echocardiogram. B-type natriuretic peptide assay Simultaneously to echocardiography, blood sample was drawn for measurement of BNP. Samples were drawn in EDTA tubes and BNP was measured in whole blood, by immunofluorescence technique, using a commercially available kit (Triage ® BNP test of Biosite Inc., San Diego, CA, USA). All measurements were performed within 30 minutes of blood sampling. Patients with levels of BNP > 400 pg/mL were considered congested, 14 and with levels of BNP < 200 pg/mL were considered “dry”. 15 Echocardiogram evaluation All patients were submitted to a transthoracic echocardiography with tissue Doppler imaging (GE Vivid 7, Wauwatosa, WI, USA) within a maximum of 30 minutes after completion of the physical exam. In each center, only one examiner (the most experienced) performed all echocardiographic evaluations. Echocardiographic measurements were performed in a blinded manner: the examiner was unaware of the physical findings. Images were obtained frompatients in the left lateral and recumbent position, and measurements followed the recommendations of the American Society of Echocardiography. 16 All Doppler profiles were recorded in an apical 4-chamber view. The estimated left atrial pressure (LAP) was calculated as follows: calculation of the E/E' ratio by measuring the intra‑myocardial flow velocity with tissue Doppler. The early diastolic mitral annular velocity (E') was obtained by tissue Doppler in the LV lateral wall and in case of technical impossibility of obtaining the velocity in this wall, as in ischemic involvement, it was measured in the interventricular septum. At least three consecutive cardiac cycles were used and an average was used as the final result. This measurement, when combined with the trans-mitral flow obtained with pulsed Doppler in early diastole (E) results in the relationship E/E'. The LAP was then estimated by the formula: LAP: 1.24 x (E/E’) + 1.9. Indication of increased LV filling pressure was defined as LAP ≥ 15 mm Hg. Although patients with values below 15 mm Hg may have congestion, values ≥ 15 mm Hg have high specificity for increased LV filling pressure. Ejection fraction was evaluated through the Simpson’s method. Statistical analysis Descriptive statistics were expressed as frequency (%) for categorical variables. For continuous variables data are presented as means ± standard deviation for normally distributed data or median and interquartile range (IQR) for non-normally distributed data. Measures of diagnostic performance (sensitivity, specificity, accuracy, positive and negative predictive values) were used to evaluate the diagnostic utility of physical exam signs of heart failure and/or BNP in predicting LAP ≥ 15 mm Hg (defined as indication of increased LV filling pressure). The Spearman test was used to analyze the correlation between non-normal distribution variables. The level of significance was 5%. To determine the best cut-off value for BNP to estimate elevation in LAP, a receiver operating characteristic (ROC) curve was constructed. A clinical score (CS) was built by giving 1 point to each positive sign of decompensated heart failure (elevated jugular venous distension, hepatojugular reflux, hepatomegaly, pulmonary rales or edema). Patients with 271