Plasma concentration of atrial natriuretic peptide at admission and risk of cardiac death in patients with acute myocardial infarction.

OBJECTIVE To compare the concentration of plasma atrial natriuretic peptide in patients with acute myocardial infarction with a healthy population and to determine whether a raised concentration of plasma atrial natriuretic peptide at admission was a predictor of mortality after acute myocardial infarction. DESIGN Patients with acute myocardial infarction were divided into a group with no congestion (class I) and a group with congestion (class II-IV) according to their highest Killip classification in the first 24 hours after infarction. The concentration of plasma atrial natriuretic peptide was measured at admission. On the basis of the concentration of atrial natriuretic peptide measured in the healthy population, patients were separated into two groups: a group with a high (greater than 200 pg/ml) and a group with a low concentration of atrial natriuretic peptide (less than or equal to 200 pg/ml). The patients were followed for three years. PATIENTS 55 patients admitted to the coronary care unit within 12 hours of the appearance of symptoms of acute myocardial infarction were compared with 51 healthy individuals. MAIN OUTCOME MEASURES Plasma atrial natriuretic peptide, Killip class, mortality. RESULTS The patients had significantly higher concentrations of atrial natriuretic peptide than the healthy controls. Furthermore, patients with congestion had a significantly higher concentration of atrial natriuretic peptide than the uncongested group of patients. Total mortality was 34.5%. In the group with a low concentration of atrial natriuretic peptide the mortality was only 13.6%, whereas mortality was significantly higher (48.5%) in the group with a high concentration. CONCLUSIONS The measurement of atrial natriuretic peptide separated the patients into low and high risk groups after acute myocardial infarction.