Israel Medical Association Journal

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.
 

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.