Serial analyses of N-terminal pro-B-type natriuretic peptide in patients with non-ST-segment elevation acute coronary syndromes: a Fragmin and fast Revascularisation during In Stability in Coronary artery disease (FRISC)-II substudy.

OBJECTIVES: The aim of this research was to describe N-terminal part of the pro-B-type natriuretic peptide (NT-proBNP) levels over time in non-ST-segment elevation acute coronary syndromes (NSTEACS), to elucidate factors associated with changes of NT-proBNP levels, and to examine association with long-term mortality.

BACKGROUND: The NT-proBNP levels are associated with mortality. Long-term temporal changes of NT-proBNP levels and their relation to other factors have not been examined.

METHODS: The NT-proBNP was analyzed at randomization and at 48 h, after 6 weeks, 3 and 6 months in NSTEACS patients enrolled in the Fragmin and fast Revascularisation during InStability in Coronary artery disease (FRISC)-II trial. The NT-proB-type natriuretic peptide was analyzed at least three time points in 1,216 patients.

RESULTS: The median NT-proBNP level, which at randomization was 529 ng/l, decreased throughout the whole sampling period to 238 ng/l at six months. Elevated troponin T, C-reactive protein, and female gender were associated with higher reduction rates, and high age, diabetes, previous myocardial infarction, treatment with diuretics, and nitrates on admission with lower reduction rates. At each time point, the NT-proBNP level was predictive of the two-year mortality. However, the adjusted odds ratio increased for each time point.

CONCLUSIONS: The initial rise of NT-proBNP in NSTEACS is mainly reversible. Factors associated with less reversibility are related to chronically impaired left ventricular function, and factors associated with greater reversibility are related to the acute myocardial damage. The NT-proBNP level measured during a chronic, relatively stable phase is a better predictor of mortality than during an acute unstable phase. The clinical setting and timing of measurement will be important to consider when using NT-proBNP for risk assessment.