Israel Medical Association Journal

Background: The identification of the etiology of a pleural effusion can be difficult. Measurement of serum B-type natriuretic peptide (BNP) levels is helpful in the diagnosis of congestive heart failure (CHF) as a cause of respiratory failure, but pleural fluid BNP measurement is still not part of the workup for pleural effusion.

Objectives: To identify the correlation between pleural fluid BNP levels and clinical diagnosis.

Methods: In this cross-sectional study, data from 107 patients admitted to the department of internal medicine between November 2009 and January 2015 were obtained from medical records. Patients underwent a diagnostic thoracocentesis as part of their evaluation. They were grouped according to final diagnosis at discharge and clinical judgment of the attending physician.

Results: Serum BNP levels were significantly higher in the CHF patients compared to patients with non-cardiac causes of pleural effusion (1519.2 and 314.1 respectively, P < 0.0001). Mean pleural fluid BNP was also significantly higher in the CHF patients (1063.2 vs. 208.3, P < 0.0001). Optional cutoff points to distinguish between cardiac and non-cardiac etiology of pleural effusion were 273.4 pg/ml (sensitivity 83.3%, specificity 72.3%, accuracy 76.7%) or 400 pg/ml (sensitivity 78.6%, specificity 86.2%, accuracy 83.0%). A strong correlation was found between serum BNP and pleural fluid BNP levels.

Conclusions: High levels of serum BNP in patients presenting with pleural effusion suggest CHF. In cases with doubt regarding the etiology of pleural effusion, high levels of pleural fluid BNP can support the diagnosis, but are not superior to serum BNP levels.

Background: When a patient arrives at the emergency department (ED) presenting with symptoms of acute decompensated heart failure (ADHF), it is possible to reach a definitive diagnosis through many different venues, including medical history, physical examination, echocardiography, chest X-ray, and B-type natriuretic peptide (BNP) levels. Point-of-care ultrasound (POCUS) has become a mainstream tool for diagnosis and treatment in the field of emergency medicine, as well as in various other departments in the hospital setting. Currently, the main methods of diagnosis of ADHF using POCUS are pleural B-lines and inferior vena cava (IVC) width and respiratory variation.

Objectives: To examine the potential use and benefits of bedside ultrasound of the jugular veins in the evaluation of dyspneic patients for identification of ADHF.

Methods: A blood BNP level was drawn from each participant at time of recruitment. The area and size of the internal jugular vein (IJV) during inspiration and expiration were examined.

Results: Our results showed that the respiratory area change of the IJVs had a specificity and sensitivity of nearly 70% accuracy rate in indentifying ADHF in our ED.

Conclusions: Ultrasound of the IJV may be a useful tool for the diagnosis of ADHF because it is easy to measure and requires little skill. It is also not affected by patient body habitus.

Objectives: To investigate the predictive value of BNP levels regarding the severity of the postoperative course in infants undergoing surgical repair of congenital heart disease.

Methods: We conducted a prospective comparative study. Plasma BNP levels in infants aged 1–12 months with congenital heart disease undergoing complete repair were measured preoperatively and 8, 24 and 48 hours postoperatively. Demographic and clinical data included postoperative inotropic support and lactate level, duration of mechanical ventilation, intensive care unit (ICU) and hospitalization stay.

Results: Cardiac surgery was performed in 19 infants aged 1-12 months. Preoperative BNP level above 170 pg/ml had a positive predictive value of 100% for inotropic score ≥ 7.5 at 24 hours (specificity 100%, sensitivity 57%) and 48 hours (specificity 100%, sensitivity 100%), and was associated with longer ICU stay (P = 0.05) and a trend for longer mechanical ventilation (P = 0.12). Similar findings were found for 8 hours postoperative BNP above 1720 pg/ml. BNP level did not correlate with measured fractional shortening.

Conclusions: In infants undergoing heart surgery, preoperative and 8 hour BNP levels were predictive of inotropic support and longer ICU stay. These findings may have implications for preplanning ICU loads in clinical practice. Further studies with larger samples are needed.

Background: Cardiac patients express elevated levels of B-type natriuretic peptide and the amino terminal segment of its prohormone (NT-proBNP). However, there are non-cardiac causes of NT-proBNP level elevation.

Objectives: To determine the upper limit of NT-proBNP for pediatric patients with acute non-cardiac disease.

Methods: We compared NT-proBNP concentrations in healthy children and children with acute non-cardiac, mostly febrile, and acute cardiac disease. We used the Student t-test and Mann-Whitney test for group comparisons, and Pearson's and Spearman's correlation coefficients to test relationships between variables. 

Results: In 138 patients with acute non-cardiac diseases (mean age 3.7 years, 53% male), median NT-proBNP concentration was 162 pg/ml, upper limit (95% percentile) 1049 pg/ml. The level did not vary significantly by disease category; was negatively correlated with weight, weight percentile, age and hemoglobin level; and positively correlated with creatinine level. Multivariant analysis showed weight to be the only factor influencing NT-proBNP level. Levels were higher in children with acute non-cardiac diseases versus healthy children (median 88 pg/ml, P < 0.001, n= 59), and lower than levels in patients with acute cardiac disease (median 29,986 pg/ml, P < 0.001, n=29). Receiver operating characteristic analysis showed good NT-proBNP performance for differentiation between children with acute cardiac versus non-cardiac disease (area under the curve 0.958), at a cutoff of 415 pg/ml.

Conclusions: NT-proBNP levels are higher in children with acute non-cardiac diseases than in healthy children, but lower than in children with acute cardiac disease. NT-proBNP negatively correlated with weight and weight percentile.
 

Background: Surgical repair of tetralogy of Fallot may leave the patient with pulmonary regurgitation causing eventual right ventricle dilatation and dysfunction. Predicting clinical deterioration may help to determine the best timing for intervention.

Objectives: To assess whether the clinical and humoral status of patients in the second decade after repair of ToF[1] is worse than that of patients in the first decade after repair.

Methods: Twenty-one patients with repaired ToF underwent clinical assessment, electrocardiogram, echocardiogram and measurement of plasma B-type natriuretic peptide and N-terminal pro-BNP[2] as well as the 6 minute walk distance test. Patients were divided into two groups: group A – less than 10 years after repair (n=10, age < 12 years old), and group B – more than 10 years after repair (n=11, age > 12 years old). The age at repair was similar in both groups.

Results: In all but one patient the distance in the 6 min walk test was less than the minimum for age. RV[3] end-diastolic volume and the 6 min walk test correlated with age. NT-proBNP[4] levels were significantly higher in the ToF group compared to 26 healthy controls (P < 0.0001) and were inversely correlated with RV ejection fraction. Comparison of the two groups showed no difference in RV end-diastolic volume indexed for body surface area, pulmonary regurgitation severity, right or left ventricular myocardial performance index, RV ejection fraction, QRS duration, or 6 min walk indexed to minimum for age.

Conclusions: In this group of patients with similar age at operation and pulmonary regurgitation severity, most clinical, echocardiographic and humoral parameters were not worse in the second decade after repair of ToF. These data suggest that very early pulmonary valve replacement may not be of benefit.

Objectives: To evaluate the safety and efficacy of external counter-pulsation therapy in heart failure patients.

Methods: Fifteen symptomatic heart failure patients (subsequent to optimal medical and device therapy) underwent 35 hourly sessions of ECPT[1] over a 7 week period. Before and after each ECPT session we performed pro-B-type natriuretic peptide and brachial artery function studies, administered a quality of life questionnaire, and assessed exercise tolerance and functional class.

Results: Baseline left ventricular ejection fraction was 28.1 ± 5.8%. ECPT was safe and well tolerated and resulted in a reduction in pro-BNP[2] levels (from 2245 ± 2149 pcg/ml to 1558 ± 1206 pcg/ml, P = 0.022). Exercise duration (Naughton protocol) improved (from 720 ± 389 to 893 ± 436 seconds, P = 0.0001), along with functional class (2.63 ± 0.6 vs. 1.93 ± 0.7, P = 0.023) and quality of life scores (54 ± 22 vs. 67 ± 23, P = 0.001). Nitroglycerine-mediated brachial vasodilatation increased (11.5 ± 7.3% vs. 15.6 ± 5.2%, P =0.049), as did brachial flow-mediated dilation (8.35 ± 6.0% vs. 11.37 ± 4.9%, P = 0.09).

Conclusions: ECPT is safe for symptomatic heart failure patients and is associated with functional and neurohormonal improvement. Larger long-term randomized studies with a control arm are needed to confirm these initial encouraging observations.

Objectives: To test whether an early change in neurohormonal and inflammatory markers after implantation can predict the clinical response to CRT.

Methods: The study group included 32 patients with advanced symptomatic systolic heart failure and a prolonged QRS complex and who were assigned to undergo CRT. Baseline plasma levels of B-type natriuretic peptide and high sensitivity C-reactive protein were determined in the peripheral venous blood and coronary sinus. Post-implantation levels were determined 2 weeks post-procedure in the PVB[2]. Baseline levels and their change in 2 weeks were correlated with all-cause mortality and hospitalization for congestive heart failure.

Results: At baseline, coronary sinus levels of BNP[3] but not hsCRP[4] were significanly elevated compared to the PVB. Compared to baseline levels, BNP and hsCRP decreased significantly within 2 weeks after the implantation (BNP mean difference 229.1 ± 102.5 pg/ml, 95% confidence interval 24.2–434, P < 0.0001; hsCRP mean difference 5.2 ± 2.4 mg/dl, 95% CI[5] 0.3–10.1, P = 0.001). During a mean follow-up of 17.7 ± 8.2 months 6 patients died (18.7%) and 12 (37.5%) were hospitalized due to exacerbation of CHF[6]. Baseline New York Heart Association and CS[7] BNP levels predicted CHF-related hospitalizations. HsCRP levels or their change over 2 weeks did not predict all-cause mortality or hospitalizations.

Conclusions: BNP levels in the CS and peripheral venous blood during biventricular implantation and 2 weeks afterwards predict cilinical response and may guide patient management.