Plasma N-terminal B-Type natriuretic peptide as an indicator of long-term survival after acute myocardial infarction: comparison with plasma midregional pro-atrial natriuretic peptide: the LAMP (Leicester Acute Myocardial Infarction Peptide) study.

OBJECTIVES: Our aim was to assess the prognostic value of midregional pro-atrial natriuretic peptide (MR-proANP) in patients after acute myocardial infarction (AMI).

BACKGROUND: Multimarker strategies may assist risk stratification after AMI. Midregional pro-atrial natriuretic peptide is a newly described stable fragment of N-terminal pro-atrial natriuretic peptide. We compared the prognostic value of MR-proANP and an established marker, N-terminal pro-B-type natriuretic peptide (NT-proBNP), after AMI.

METHODS: We recruited 983 consecutive post-AMI patients (720 men, median age 65 [range 24 to 95] years) in a prospective study with follow-up over 343 (range 0 to 764) days.

RESULTS: Plasma MR-proANP was raised in patients who died (n = 101) compared with that seen in survivors (median 310 [range 48 to 1,150] pmol/l vs. 108 [range 4.9 to 1,210] pmol/l, p < 0.0001). Using Cox modeling, log(10)MR-proANP (hazard ratio 3.87) and log(10)NT-proBNP (hazard ratio 3.25) were significant independent predictors of death. In patients stratified by NT-proBNP in the highest quartile (> approximately 5,900 pmol/l), MR-proANP in the top quartile ( approximately 330 pmol/l) was associated with poorer outcome (p < 0.0001). Findings were similar for heart failure as an individual end point. However, neither marker predicted recurrent AMI.

CONCLUSIONS: The A- and B-type natriuretic systems are activated after AMI. Midregional pro-atrial natriuretic peptide is a powerful predictor of adverse outcome, especially in those with an elevated NT-proBNP. Midregional pro-atrial natriuretic peptide may represent a clinically useful marker of prognosis after an AMI as part of a multimarker strategy targeting the natriuretic neurohormonal pathway.