Prognostic Implications of Plasma Levels of Atrial Natriuretic Factor in Patients with Acute Myocardial Infarction.

Several neurohormonal factors have been proposed as markers of the severity of acute myocardial infarction (MI). To determine whether plasma concentrations of atrial natriuretic factor (ANF) might predict post-MI prognosis, we studied 130 patients with acute MI (97 males and 33 females, mean age 62 years). Within one-half to one day after admission, a blood sample was taken for estimation of circulating ANF. The mean follow-up period was 37 months, and the follow-up rate was 97%. Of the 130 patients, 28 died from cardiac causes during the follow-up period. Patients were classified into three groups according to plasma ANF levels (group 1, < 99 pg/ml; group 2, 100-199 pg/ml; group 3; > 200 pg/ml). The survival curves were constructed by the Kaplan-Meier method. There were significant differences in the cumulative survival rate among the three groups (group 1 > group 2 > group 3; p < 0.001). The baseline characteristics (age, atrial pressure, and cardiac index) were different among the groups, therefore these variables were analyzed by a Cox multiple regression model. Significant predictors of cardiac mortality were plasma ANF class (p < 0.002) and pulmonary capillary wedge pressure (p < 0.007). In conclusion, these observations demonstrated that stratification of acute MI patients by plasma ANF level is a useful non-invasive method for predicting prognosis and for identifying individuals at high risk of cardiac death.