Boston, MA- B-type natriuretic peptide (BNP) is released from cardiac myocytes in response to increased wall stress and is elevated in response to myocardial ischemia. BNP levels are used as prognostic markers of Acute Coronary Syndrome (ACS) and response to therapy for ACS. David Morrow, MD, MPH et al from Brigham and Women’s Hospital conducted a study evaluating serial measurements of BNP during extended follow-up of patients after ACS, thereby determining the prognostic value of BNP prior to hospital discharge, at four months and at 12 months after discharge. The study, published in the December 14, 2005 issue of the Journal of the American Medical Association, found serial determinations of BNP levels during outpatient follow-up after ACS predict the risk of death or new CHF.

A group of 4497 patients with non-ST elevation or ST-elevation ACS participated in this prospective, observational study. Samples of plasma were obtained prior to randomization into the trial, shortly after onset of symptoms, and at outpatient follow-up at 4 months and 12 months.

Levels of BNP were available in 4266 patients at study entry (prior to hospital discharge), 3618 patients at 4 months, and 2966 patients at 12 months. During follow-up there were 230 deaths and 163 incident cases of CHF. Adjusting for age, sex, index event, renal function, hypertension, prior heart failure, and diabetes, elevated levels of BNP (>80 pg/mL) were associated with subsequent death or new CHF when measured at study entry (111 [21%] vs 246 [7%]; adjusted hazard ratio [HR], 2.5; 95% confidence interval [CI], 2.0-3.3), at 4 months (34 [19%] vs 125 [4%]; adjusted HR, 3.9; 95% CI, 2.6-6.0), and at 12 months (19 [11%] vs 37 [1%]; adjusted HR, 4.7; 95% CI, 2.5-8.9). Patients with newly elevated levels of BNP at 4 months were at increased risk of death or new CHF (10 [15%] vs 105 [3%]); HR, 4.5; 95% CI, 2.3-8.6). Patients with elevated levels of BNP at study entry and with BNP levels lower than 80 pg/mL at 4 months tended to have only modestly increased risk (HR, 1.7; 95% CI, 1.0-2.9) compared with patients with BNP levels lower than 80 pg/mL at both visits.

Serial determinations of BNP levels during outpatient follow-up after ACS predict the risk of death or new CHF. Changes in BNP levels over time are associated with long-term clinical outcomes and may provide a basis for enhanced clinical decision making in patients after onset of ACS.