[Relationship between plasma brain natriuretic peptide concentration and clinical prognosis in patients of acute myocardial infarction].

OBJECTIVE: To evaluate the value of brain natriuretic peptide (BNP) in estimating risk stratification in patients with acute myocardial infarction (AMI) and to determine the relationship between BNP and adverse cardiac events after AMI.

METHODS: The 135 subjects were selected into the study, including 25 healthy subjects and 110 patients with a first AMI. The plasma concentrations of BNP were measured at two to four days after infarction in patients and healthy controls. Left ventricular function was evaluated by echocardiography with the parameters of left ventricular ejection function (LVEF) after 3 months. Patients were followed up at 12 months. The main outcome measures were heart failure, left remodeling, mortality and other adverse cardiac events at one year.

RESULTS: Plasma BNP concentrations in patients with AMI were much higher than those in the health control people (416.7 +/- 208.0 ng/L versus 61.8 +/- 34.1 ng/L, P < 0.01). The BNP count ranged from 5 to 2500 ng/L in AMI patients. There was no association between the BNP count and mortality rate. The development of new congestive heart failure (CHF) was associated with a higher BNP count (P = 0.02). The development of any of the clinical end points (death/CHF/shock) occurred more frequently in patients with a higher BNP count (13.8% for BNP count of < 100 ng/L, 39.1% for BNP count of 100 - 200 ng/L, 43.3% for BNP count of 200 - 400 ng/L, 46.4% for BNP count of > 400 ng/L; P = 0.019). Plasma BNP concentrations remained independently associated with the development of clinical end points in multivariable model that adjusted for potential confounding variables.

CONCLUSION: The results of the present study confirm that the elevated BNP count related to the risk stratification and prognosis in patients with AMI. Elevations in BNP count are associated with a higher incidence of new CHF and adverse clinical outcomes after AMI. It could serve as a strong predictor for the subsequent development of poor outcomes in AMI patients.