The Early Changing Pattern of the B-Type Natriuretic Peptide Concentration and its Significance as a Prognostic Marker after Acute Myocardial Infarction

Choe, Hyunmin; Yoo, Byung Su; Ryu, Ho Yeol; Koh, Sang Baek; Chang, Sei Jin; Hwang, Sung Oh; Kim, Jang Young; Lee, Seung Whan; Yoon, Junghan; Choe, Kyung Hoon

Abstract

BACKGROUND AND OBJECTIVES: The BNP concentration varies considerably after the onset of AMI, and this makes it difficult to determine the right time to measure the BNP as a valid prognostic marker. The aim of this study was to examine the early changing patterns of BNP and to decide on the suitable time for measuring the BNP as a prognostic marker after the onset of AMI.
SUBJECTS AND METHODS
From Feb 2002 to May 2005, we analyzed the changing patterns of BNP in 321 AMI patients. BNP (Triage(R)) was measured at the acute phase (< or = 24 hr), the early phase (2 to 6 day), the late phase (1 to 4 week) & the long-term phase (>4 week) after the onset of AMI. The end points were major adverse cardiac events (MACE) and cardiovascular death (CVD).
RESULTS
The mean BNP was 306.2+/-802.8 at the acute phase (mean: 9.5 hours), 251.9+/-592.8 at the early phase (mean: 5.1 days), 103.1+/-172.9 at the late phase (mean: 26.8 days) and 179.7+/-353.3 pg/mL at the long-term phase (mean: 45.9 days). There were no significant differences of the demographic factors between the MACE and Non-MACE group. Multivariative analysis showed that early phase BNP (p=0.007) and male gender (p=0.009) were significant risk factors for MACE. The early phase BNP (p=0.037) and age (p=0.022) were the significant risk factors of CVD. On the ROC curve, the early phase BNP for predicting the CVD risk was 186 pg/mL (AUC=0.87, p<0.001). The Kaplan-Meier survival curve showed that the survival rate was higher for the patients with an early phase BNP<186 pg/mL than it was for those patients with a BNP> or = 186 pg/mL (p=0.000).
CONCLUSION
The early levels or changing patterns of the BNP concentrations following AMI showed different patterns of change depending on several prognostic factors. The early phase (2 to 6 day) BNP concentration after the onset of AMI could be used as a significant prognostic marker.