Predictive value of repeated versus single N-terminal pro B-type natriuretic peptide measurements early after-myocardial infarction.

BACKGROUND

A single, markedly elevated B-type natriuretic peptide (BNP) serum concentration predicts an increased risk of death after myocardial infarction (MI), though its sensitivity and predictive accuracy are low. We compared the predictive value of a modestly and persistently elevated, versus a single, markedly elevated measurement of N terminal pro-BNP (NT-BNP) early after MI.

METHODS AND RESULTS

NT-BNP was measured 2-4, 6-10, and 14-18 weeks after MI. The median age of the 100 patients was 61 years, median left ventricular ejection fraction (LVEF) was 0.40, and 88% were males. Over a median follow-up of 39 months, 10 patients died. The initial median NT-BNP was 802 pg/mL and declined over time (P = 0.002). An initial NT-BNP > or =2,300 pg/mL (upper quintile) was observed in 19 patients and predicted a 3.4-fold higher independent risk of death (P = 0.05), with modest sensitivity (30%) and positive predictive accuracy (16%). A NT-BNP consistently > or =1,200 pg/mL (upper tertile) was observed in 19 patients, and was associated with a 5.7-fold higher independent risk of death (P = 0.01), with a higher sensitivity (50%) and positive predictive accuracy (26%) than a single, markedly elevated NT-BNP measurement.

CONCLUSIONS

A moderately and persistently elevated NT-BNP in the early post-MI period was associated with a 5.7-fold higher risk of death, independent of age, LVEF, and functional class. Compared with a single measurement, serial NT-BNP measurements early after MI were more accurate predictors of risk of death.