Atrial Fibrillation Impairs the Diagnostic Performance of Cardiac Natriuretic Peptides in Dyspneic Patients: Results From the BACH Study (Biomarkers in ACute Heart Failure)

Study Questions:

What is the effect of atrial fibrillation (AF) on the diagnostic performance of mid-region amino terminal pro-atrial natriuretic peptide (MR-proANP), in comparison to B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP), in patients enrolled in the BACH (Biomarkers in Acute Heart Failure) trial?

Methods:

This was a post-hoc analysis. The BACH trial was a prospective, multicenter, international study of patients presenting to the emergency department with acute dyspnea. Results previously indicated noninferiority for MR-proANP for diagnosis of heart failure (HF). A total of 1,445 patients had measurements taken of MR-proANP, BNP, and NT-proBNP on enrollment to the BACH trial, and were grouped according to presence or absence of AF and HF. The discriminative power of each peptide for the diagnosis of HF was analyzed separately for AF and non-AF patients by receiver-operator characteristic (ROC) curve analysis.

Results:

Of the 1,445 patients included in the current analysis, 557 (38.5%) had HF, and 242 (16.7%) had AF. AF was more common in those with HF than in those without (27.5% and 10%, respectively, p < 0.001). There was a significant increase in the levels of all three peptides in patients with AF without HF (p < 0.001 for all three peptides) and a further step up in levels in HF with or without AF (p < 0.001 for all peptides). Areas under ROC curves for discrimination of acute HF were substantially reduced in the presence of all three peptides in those with AF (0.701-0.757).

Conclusions:

The authors concluded that the performance of natriuretic peptides (MR-proANP, BNP and NT-proBNP) in the diagnosis of acute HF in dyspneic patients is impaired by AF.

Perspective:

Results from this analysis of the BACH trial demonstrate that the performance of MR-proANP, BNP, and NT-proBNP is impaired by the presence of AF. Peptide thresholds derived from non-AF patients result in preserved sensitivity, but reduced specificity. Such findings have implications for considering different threshold values for natriuretic peptides to diagnose HF in the presence of AF in dyspneic patients.

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

Keywords: Heart Diseases, Biological Markers, Troponin I, Heart Failure, ROC Curve, Dyspnea, Atrial Natriuretic Factor, Natriuretic Peptide, Brain


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