Serial bedside B-type natriuretic peptide strongly predicts prognosis in acute coronary syndrome independent of echocardiographic abnormalities.
BACKGROUND
Elevated levels of B-type natriuretic peptide (BNP) are associated with adverse clinical outcomes in acute coronary syndrome (ACS), but several questions remain outstanding. Firstly, it has not yet been determined whether an additional BNP sample at 7 weeks post ACS would enhance risk prediction. Secondly, we assessed whether the prognostic potential of BNP in ACS could be explained by echocardiographic abnormalities such as left ventricular hypertrophy (LVH).


METHODS
We measured bedside BNP levels in 443 consecutive patients presenting with ACS and at 7 weeks outpatient follow-up. Main outcome measure was either all-cause mortality, readmission with ACS, or congestive heart failure) at 10 months from presentation.


RESULTS
Of the 443 patients, 120 patients presented with ST-elevation myocardial infarction (27%). There were 90 cardiovascular (CV) events at 10 months. Adjusting for age, sex, hypertension, diabetes mellitus, smoking status, renal dysfunction, left ventricular ejection fraction, and echocardiographic LVH elevated near patient BNP levels (>80 pg/mL) were still associated with subsequent CV events when measured on admission (adjusted relative risk [RR] 2.63 [95% CI 1.34-5.19)] and also at 7 weeks post ACS (adjusted RR 4.12 [95% CI 1.58-10.72]). Patients with persistent BNP elevation at 7 weeks were also at an increased risk of CV events compared to those with an initial high BNP which then fell (unadjusted RR 4.04 [95% CI 1.24-13.15]).


CONCLUSIONS
In ACS, bedside BNP levels predict CV events at 10 months, independent of many echocardiographic abnormalities including LVH. Furthermore, our study suggests that an additional 7 weeks post ACS BNP enhances risk stratification over and above a one-off high BNP at baseline.
Ang
Donald S C
DS
Division of Medicine and Therapeutics, University of Dundee, Ninewells Hospital and Medical School, Dundee, UK. donaldscang@doctors.org.uk
Kong
Colin F J
CF
Kao
Michelle P C
MP
Struthers
Allan D
AD
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis / Q000401:mortality; D000368:Aged; D016279:Atrial Function, Left / Q000502:physiology; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis / Q000401:mortality; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000175:diagnosis / Q000401:mortality; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000175:diagnosis / Q000401:mortality; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D011379:Prognosis; D012016:Reference Values; D012307:Risk Factors; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000175:diagnosis / Q000401:mortality
D020097:Natriuretic Peptide, Brain