BACH - BACH

Description:

Mid-regional pro-Adrenomedullin (MR-proADM) is a novel biomarker, which reflects vascular and endothelial status of the heart and the microcirculation. The BACH trial sought to compare the efficacy of MR-proADM and brain natriuretic peptide (BNP) and N-terminal portion of probrain natriuretic peptide (NT-proBNP) in prognosticating patients presenting with shortness of breath.

Hypothesis:

MR-proADM would be associated with a significant improvement in the prognostication of patients presenting to the emergency room with shortness of breath.

Study Design

  • Blinded
  • Parallel

Patients Enrolled: 1,641
Mean Follow Up: 90 days
Mean Patient Age: 64 years
Female: 48

Patient Populations:

  • Presentation to the emergency department with shortness of breath
  • Physician assessment for heart failure

Exclusions:

  • Shortness of breath from trauma, obvious MI
  • Dialysis

Primary Endpoints:

  • Prediction of 90-day all-cause mortality in patients presenting to the emergency department with shortness of breath, and diagnosed with CHF

Secondary Endpoints:

  • 90-day all-cause mortality in patients presenting with non-CHF causes of shortness of breath
  • 90-day all-cause mortality in all patients presenting with shortness of breath

Drug/Procedures Used:

All patients received medical management, as indicated. Blood levels of BNP, NT-proBNP, and MR-proADM were assessed.

Principal Findings:

A total of 1,641 patients were enrolled, of which 568 had congestive heart failure (CHF), and 1,073 had other causes of shortness of breath (non-CHF). About 36% had a history of prior CHF, 19% had a history of prior myocardial infarction (MI), and 29% had diabetes.

In the group admitted with CHF, MR-proADM was associated with a higher prognostic accuracy (73.5%) compared with BNP (60.8%) and NT-proBNP (63.6%) (p

Adding MR-proADM to BNP and NT-proBNP was associated with an improvement in prognostication (p 0.20). However, the c-index for this biomarker, a measure of discrimination, was about 0.67 compared with 0.60 for BNP, suggesting poor discriminative ability for both biomarkers.

When levels of MR-proADM were studied in all patients with shortness of breath, it was still associated with a higher prognostic ability than BNP or NT-proBNP. Even in patients without CHF, high levels of MR-proADM were associated with a significant improvement in the prognostic ability compared with those with low levels of this biomarker (p-value for interaction = 0.005).

Interpretation:

BACH is a biomarker trial, and indicates that MR-proADM is associated with an improvement in the prognostic value for mortality in patients presenting with CHF, as well as non-CHF causes of shortness of breath, compared with BNP or NT-proBNP.

This is an interesting study, but does not help answer the question of diagnosis of heart failure in patients presenting with shortness of breath to the emergency department, but rather looks at their prognosis. Existing biomarkers are seldom used in prognosticating the course of heart failure; thus, the clinical utility of this biomarker is unclear.

References:

Presented by Dr. Stefan Anker at the American Heart Association Annual Scientific Sessions, New Orleans, November 2008.

Maisel A, Mueller C, Nowak R, Peacock WF, et al. Mid-region pro-hormone markers for diagnosis and prognosis in acute dyspnea: results from the BACH (Biomarkers in Acute Heart Failure) trial. J Am Coll Cardiol. 2010 May 11;55(19):2062-76.

Clinical Topics: Anticoagulation Management, Heart Failure and Cardiomyopathies, Acute Heart Failure, Heart Failure and Cardiac Biomarkers

Keywords: Prognosis, Myocardial Infarction, Biological Markers, Microcirculation, Heart Failure, Peptide Fragments, Emergency Service, Hospital, Dyspnea, Adrenomedullin, Diabetes Mellitus, Natriuretic Peptide, Brain


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