N-Terminal Pro–B-Type Natriuretic Peptide (NT-proBNP) Immunoreactivity Is Reduced After 6 Years of Storage at −70 °C

Risk Assessment after ST-Segment Elevation Myocardial Infarction: Can Biomarkers Improve the Performance of Clinical Variables?

Introduction: Myocardial infarction with ST-segment elevation (STEMI) is the coronary artery disease associated with the highest risk of morbimortality; however, this risk is heterogeneous, usually being evaluated by clinical scores. Risk assessment is a key factor in personalized clinical management of patients with this disease. Aim: The aim of this study was to assess whether some new cardiac biomarkers considered alone, combined in a multibiomarker model or in association with clinical variables, improve the short- and long-term risk stratification of STEMI patients. Materials and Methods: This was a retrospective observational study of 253 patients with STEMI. Blood samples were obtained before or during the angiography. The assessed biomarkers were C-terminal fragment of insulin-like growth factor binding protein-4 (CT-IGFBP4), high sensitive cardiac troponin T (hs-cTnT), N-terminal fragment of probrain natriuretic peptide (NT-proBNP), and growth differentiation factor 15 (GDF-15); they reflect different cardiovascular (CV) physiopathological pathways and underlying pathologies. We registered in-hospital and follow-up mortalities and their causes (cardiovascular and all-cause) and major adverse cardiac events (MACE) during a two year follow-up. Discrimination, survival analysis, model calibration, and reclassification of the biomarkers were comprehensively evaluated. Results and Discussion: In total, 55 patients (21.7%) died, 33 in-hospital and 22 during the follow-up, most of them (69.1%) from CV causes; 37 MACE occurred during follow-up. Biomarkers showed good prognostic ability to predict mortality, alone and combined with the multibiomarker model. A predictive clinical model based on age, Killip–Kimball class, estimated glomerular filtration rate (eGFR), and heart rate was derived by multivariate analysis. GDF-15 and NT-proBNP significantly improved risk assessment of the clinical model, as shown by discrimination, calibration, and reclassification of all the end-points except for all-cause mortality. The combination of NT-proBNP and hs-cTnT improved CV mortality prediction. Conclusions: GDF-15 and NT-proBNP added value to the usual risk assessment of STEMI patients.

N-Terminal-pro-Brain natriuretic peptide dynamics during effort phenotypes ischemic heart failure and determines prognosis regardless of ejection fraction

Ischemic heart disease leading to heart failure (HF) portends a high overall morbidity and mortality. A higher N-terminal-pro-B-type natriuretic peptide (NT-pro-BNP) at rest reflects HF severity and impaired cardiac output, most often secondary to reduced ejection fraction (EF). As an insufficient increase in cardiac output during exertion is common in all HF phenotypes, we examined the value of NT-pro-BNP during exercise testing as a risk stratification index for ischemic HF secondary to either reduced (HFrEF) or mid-ranged/preserved EF (HFmrEF/HFpEF). 213 patients (123 HFrEF; 90 HFmrEF/HFpEF) underwent cardiopulmonary exercise testing (CPET). NT-pro-BNP was determined at rest and peak exercise. The distribution of HFrEF and HFmrEF/HFpEF etiology in subjects with and without oxygen consumption trajectory flattening during CPET was similar (p > 0.05). Patients with HFrEF had higher plasma levels of NT-pro-BNP at rest and peak exercise than those with HFmrEF/HFpEF (984 vs. 780; 1012 vs. 845 pg/mL, p < 0.01, respectively), whereas ΔNT-pro-BNPpeak/rest was similar (60 vs. 50 pg/mL, p > 0.05). During the tracking period (22.4 ± 20.3 months) 34 patients died, and there were 2 cardiac transplantations and 3 LVAD implantations. In a multivariate regression model only the NT-pro-BNPpeak and ΔNT-pro-BNPpeak/rest were retained in the regression for the prediction of adverse events (Chi-square:8.97, p = 0.003). ROC analysis demonstrated that NT-pro-BNPpeak ≥1506 pg/mL and ΔNT-pro-BNPpeak/rest ≥108 pg/mL were optimal for identifying patients with a risk (Sn = 76.9, 74.4 %; Sp = 84.7, 80.9 %, respectively). NT-pro-BNP changes during effort and absolute peak values reached provide novel insights emerging as new and strong predictors of adverse events in HF of any EF.

A Pilot Study of the Association of Amino-Terminal Pro-B-Type Natriuretic Peptide and Severity of Illness in Pediatric Septic Shock

OBJECTIVES

Biomarkers that can measure illness severity and predict the risk of delayed recovery may be useful in guiding pediatric septic shock. Amino-terminal pro-B-type natriuretic peptide has not been assessed in pediatric septic patients at the time of presentation to the emergency department prior to any interventions. The primary aim was to assess if emergency department amino-terminal pro-B-type natriuretic peptide is associated with worse outcomes and severity of illness.

DESIGN

Prospective observational pilot study.

SETTINGS

Tertiary free-standing children's hospital.

PATIENTS

Children 0-17 years old with a diagnosis of septic shock were enrolled. Patients with preexisting cardiac and renal dysfunction were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Amino-terminal pro-B-type natriuretic peptide analysis was performed on samples obtained in the emergency department prior to any intervention. The association between biomarkers and clinical outcomes and illness severity using Pediatric RISk of Mortality 3 were assessed. Eighty-two patients with septic shock underwent analysis. The median (interquartile range) amino-terminal pro-B-type natriuretic peptide levels was 394 pg/mL (102-1,392 pg/mL). Each decile change increase in amino-terminal pro-B-type natriuretic peptide was associated with a change in ICU length of stay by 8.7%, (95% CI, 2.4-15.5), hospital length of stay by 5.7% (95% CI, 0.4-11.2), organ dysfunction by 5.1% (95% CI, 1.8-8.5), a higher inotropic score at 12, 24, and 36 hours, and longer time requiring vasoactive agents. There was a significant correlation between baseline amino-terminal pro-B-type natriuretic peptide and the Pediatric RISk of Mortality 3 score (Spearman rho = 0.247; p = 0.029).

CONCLUSIONS

This pilot study shows an association between emergency department amino-terminal pro-B-type natriuretic peptide on presentation and worse septic shock outcomes and amino-terminal pro-B-type natriuretic peptide levels correlates with an ICU severity score.