Hidehiko Aoki

Plasma brain natriuretic peptide concentrations predict survival after acute myocardial infarction.

OBJECTIVES This study sought to examine whether plasma brain natriuretic peptide levels can predict prognosis after myocardial infarction. BACKGROUND It has been suggested that concentrations of plasma brain natriuretic peptide reflect left ventricular function. Although the prognosis after myocardial infarction depends on residual left ventricular function, it is not known whether plasma levels of brain natriuretic peptide after the onset of myocardial infarction can be used to predict long-term outcome. METHODS Plasma brain natriuretic peptide and atrial natriuretic peptide levels as well as invasive hemodynamic variables were measured in 70 patients with acute myocardial infarction (53 men, 17 women; mean age 65 years). Measurements were obtained on admission (mean 6 h after onset) and on day 2 after onset. Mean follow-up period was 18 months. RESULTS Plasma brain natriuretic peptide levels measured on admission and day 2 correlated significantly with hemodynamic variables, which are influenced by left ventricular function. However, plasma atrial natriuretic peptide levels correlated with none of the hemodynamic variables measured on admission; and of those measured on day 2, plasma atrial natriuretic peptide levels correlated only with left atrial filling pressure. During the follow-up period (mean 18 +/- 7 months), 11 patients died of cardiac causes. By Kaplan-Meier analysis, it was found that patients with plasma brain natriuretic peptide levels higher than the median level, both on admission and on day 2, had significantly higher mortality rates than those with the submedian level (on admission, p < 0.01; on day 2, p < 0.05). However, only the plasma atrial natriuretic peptide level obtained immediately after admission was significantly related to survival (p < 0.01). By Cox proportional hazards model analysis of the noninvasive variables, it was found that plasma brain natriuretic peptide concentration was more closely related to survival after myocardial infarction (p = 0.0001). CONCLUSIONS Increased plasma brain natriuretic peptide concentrations in the early or subacute phase of myocardial infarction are a powerful noninvasive indicator of poor prognosis, possibly reflecting residual left ventricular function after myocardial infarction.

Relationship between Plasma Level of Brain Natriuretic Peptide and Myocardial Infarct Size

To investigate the clinical significance of plasma brain natriuretic peptide (BNP) measurement in patients with acute myocardial infarction (MI), circulating levels of BNP, atrial natriuretic peptide, creatine kinase (CK), and hemodynamic parameters were serially determined in 24 patients with a first episode of acute MI. Plasma BNP (mean +/- SEM) gradually increased and peaked 21 h after the onset (from 13.7 +/- 2.2 to 23.0 +/- 3.3 fmol/ml; p < 0.001). A significant correlation was found between the increase in plasma BNP level and both the peak CK level (r = 0.83; p < 0.05) and the MI size (r = 0.74; p < 0.05). The increase in plasma BNP in the acute phase was found to be a significant predictor of left ventricular (LV) function evaluated in the convalescent phase (LV ejection fraction, r = -0.63; p < 0.05, LV end-diastolic pressure, r = 0.56; p < 0.05). In conclusion, in patients with acute MI, increases in plasma BNP concentration during the early phase reflect MI size, and thereby may predict later LV function.

Deletion Polymorphism of the Angiotensin I-Converting Enzyme Gene Associates with Increased Risk for Late Potentials in Patients with Myocardial Infarction

Background: The pathogenesis of the occurrence of late potentials (LP) has not been fully elucidated. Deletion polymorphism in the Angiotensin I‐converting enzyme (ACE) gene may relate the myocarclial remodeling after the myocardial infarction (Ml). The purpose of this study was to evaluate the significance of ACE gene polymorphism for the occurrence of LPs after Ml.